[v2,4/4] iio: hid-sensors: Add hinge sensor driver

Message ID	20201119100331.2594-5-xiang.ye@intel.com (mailing list archive)
State	Superseded
Headers	show Return-Path: <linux-input-owner@kernel.org> IronPort-SDR: jwjnb0/oQuJroJ8GPf3paJ7wT6QDjaYOUXXzPVwliTm/OIgEIKHSayMndjxMbL0967SGGRp/rU rAg8ggWI6Jgw== IronPort-SDR: dY2SwWMrwaFN9jRlTOuyv/BejX5ijognleH92o1I/jIXm0U7/7W3SAq+/skhWwCevkEmQIEhKg CJKXeaaPHs/Q== From: Ye Xiang <xiang.ye@intel.com> To: jikos@kernel.org, jic23@kernel.org, srinivas.pandruvada@linux.intel.com Cc: linux-input@vger.kernel.org, linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org, Ye Xiang <xiang.ye@intel.com> Subject: [PATCH v2 4/4] iio: hid-sensors: Add hinge sensor driver Date: Thu, 19 Nov 2020 18:03:31 +0800 Message-Id: <20201119100331.2594-5-xiang.ye@intel.com> In-Reply-To: <20201119100331.2594-1-xiang.ye@intel.com> References: <20201119100331.2594-1-xiang.ye@intel.com> Precedence: bulk
Series	add custom hinge sensor support \| expand [v2,0/4] add custom hinge sensor support [v2,1/4] HID: hid-sensor-custom: Add custom sensor iio support [v2,2/4] iio: hid-sensor-trigger: Decrement runtime pm enable count on driver removal [v2,3/4] iio: hid-sensor-trigger: Use iio->trig instead trig field internal structure [v2,4/4] iio: hid-sensors: Add hinge sensor driver

Ye Xiang Nov. 19, 2020, 10:03 a.m. UTC

The Hinge sensor is a common custom sensor on laptops. It calculates
the angle between the lid (screen) and the base (keyboard). In addition,
it also exposes screen and the keyboard angels with respect to the
ground. Applications can easily get laptop's status in space through
this sensor, in order to display appropriate user interface.

Signed-off-by: Ye Xiang <xiang.ye@intel.com>
---
 .../hid-sensors/hid-sensor-attributes.c       |   2 +
 drivers/iio/position/Kconfig                  |  16 +
 drivers/iio/position/Makefile                 |   3 +
 .../iio/position/hid-sensor-custom-hinge.c    | 412 ++++++++++++++++++
 4 files changed, 433 insertions(+)
 create mode 100644 drivers/iio/position/hid-sensor-custom-hinge.c

Jonathan Cameron Nov. 21, 2020, 5:56 p.m. UTC | #1

On Thu, 19 Nov 2020 18:03:31 +0800
Ye Xiang <xiang.ye@intel.com> wrote:

> The Hinge sensor is a common custom sensor on laptops. It calculates
> the angle between the lid (screen) and the base (keyboard). In addition,
> it also exposes screen and the keyboard angels with respect to the
> ground. Applications can easily get laptop's status in space through
> this sensor, in order to display appropriate user interface.

I'm a little unclear on why the 3 axes aren't treated as a single sensor.
You seem to always grab the 3 together or am I missing something?

That will greatly simplify things and get rid of the need to have
a shared trigger with the problems that causes in the previous
patch.

Thanks,

Jonathan

> 
> Signed-off-by: Ye Xiang <xiang.ye@intel.com>
> ---
>  .../hid-sensors/hid-sensor-attributes.c       |   2 +
>  drivers/iio/position/Kconfig                  |  16 +
>  drivers/iio/position/Makefile                 |   3 +
>  .../iio/position/hid-sensor-custom-hinge.c    | 412 ++++++++++++++++++

Given it's custom probably needs a more specific name.  I guess
hid-sensor-custom-intel-hinge.c might be safe?

Same for other places we need names in here.

>  4 files changed, 433 insertions(+)
>  create mode 100644 drivers/iio/position/hid-sensor-custom-hinge.c
> 
> diff --git a/drivers/iio/common/hid-sensors/hid-sensor-attributes.c b/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> index 442ff787f7af..5b822a4298a0 100644
> --- a/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> +++ b/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> @@ -71,6 +71,8 @@ static struct {
>  	{HID_USAGE_SENSOR_TEMPERATURE, HID_USAGE_SENSOR_UNITS_DEGREES, 1000, 0},
>  
>  	{HID_USAGE_SENSOR_HUMIDITY, 0, 1000, 0},
> +	{HID_USAGE_SENSOR_HINGE, 0, 0, 17453293},
> +	{HID_USAGE_SENSOR_HINGE, HID_USAGE_SENSOR_UNITS_DEGREES, 0, 17453293},
>  };
>  
>  static void simple_div(int dividend, int divisor, int *whole,
> diff --git a/drivers/iio/position/Kconfig b/drivers/iio/position/Kconfig
> index eda67f008c5b..0346f6f2b422 100644
> --- a/drivers/iio/position/Kconfig
> +++ b/drivers/iio/position/Kconfig
> @@ -16,4 +16,20 @@ config IQS624_POS
>  	  To compile this driver as a module, choose M here: the module
>  	  will be called iqs624-pos.
>  
> +config HID_SENSOR_CUSTOM_HINGE
> +	depends on HID_SENSOR_HUB
> +	select IIO_BUFFER
> +	select IIO_TRIGGERED_BUFFER
> +	select HID_SENSOR_IIO_COMMON
> +	select HID_SENSOR_IIO_TRIGGER
> +	tristate "HID Hinge"
> +	help
> +	  This sensor present three angles, hinge angel, screen angles
> +	  and keyboard angle respect to horizon (ground).
> +	  Say yes here to build support for the HID SENSOR CUSTOM
> +	  HINGE.

Capitalization is a bit odd looking. I'd drop it.

> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called hid-sensor-custom-hinge.
> +
>  endmenu
> diff --git a/drivers/iio/position/Makefile b/drivers/iio/position/Makefile
> index 3cbe7a734352..7a6225977a01 100644
> --- a/drivers/iio/position/Makefile
> +++ b/drivers/iio/position/Makefile
> @@ -5,3 +5,6 @@
>  # When adding new entries keep the list in alphabetical order
>  
>  obj-$(CONFIG_IQS624_POS)	+= iqs624-pos.o
> +
> +obj-$(CONFIG_HID_SENSOR_CUSTOM_HINGE) += hid-sensor-custom-hinge.o

Alphabetical order preferred.

> +ccflags-y	+= -I$(srctree)/drivers/iio/common/hid-sensors

Why?

> diff --git a/drivers/iio/position/hid-sensor-custom-hinge.c b/drivers/iio/position/hid-sensor-custom-hinge.c
> new file mode 100644
> index 000000000000..a91b333f36fa
> --- /dev/null
> +++ b/drivers/iio/position/hid-sensor-custom-hinge.c
> @@ -0,0 +1,412 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * HID Sensors Driver
> + * Copyright (c) 2020, Intel Corporation.
> + */
> +#include <linux/hid-sensor-hub.h>
> +#include <linux/iio/buffer.h>
> +#include <linux/iio/iio.h>
> +#include <linux/platform_device.h>
> +
> +#include "hid-sensor-trigger.h"
> +
> +/* Channel definitions */
> +static const struct iio_chan_spec hinge_channels[] = {
> +	{ .type = IIO_ANGL,
> +	  .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> +	  .info_mask_shared_by_type =
> +		  BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_SCALE) |
> +		  BIT(IIO_CHAN_INFO_SAMP_FREQ) | BIT(IIO_CHAN_INFO_HYSTERESIS),
> +	  .scan_type.realbits = 16,
> +	  .scan_type.storagebits = 32,

It a bit odd to see a single channel that is 16 bits inside a 32 bit with
no shift or similar.  Why not just pack it into 16 bits?

> +	  .scan_type.sign = 's',
> +	  .scan_index = 0 },
> +
> +	IIO_CHAN_SOFT_TIMESTAMP(1)
> +};
> +
> +struct hinge_state {
> +	struct iio_dev *indio_dev;
> +	struct hid_sensor_hub_attribute_info hinge;
> +	/* Reserve for 1 channel + pading + timestamp */
> +	u32 hinge_val[1 + 3];

__aligned(8)

see below for requirements on this.
Perhaps better to use

	struct hinge_scan {
		u32 val;
		s64 timestamp __aligned(8); // Note this is needed for x86_32
	} scan;

> +	int scale_pre_decml;
> +	int scale_post_decml;
> +	int scale_precision;
> +	int value_offset;
> +	int64_t timestamp;
> +	u32 hinge_address;
> +};
> +
> +#define IIO_DEV_NUM 3

That needs a prefix to make it clear it's not a generic constant
but is specific to this driver.

> +
> +struct hinge_group {
> +	struct hinge_state *hg_states[IIO_DEV_NUM];
> +	struct hid_sensor_hub_callbacks callbacks;
> +	struct hid_sensor_common common_attributes;
> +};
> +
> +static struct hinge_group *hg_group;

We shouldn't see globals like this. Please figure out how to avoid it.

> +
> +/* Channel read_raw handler */
> +static int hinge_read_raw(struct iio_dev *indio_dev,
> +			  struct iio_chan_spec const *chan, int *val, int *val2,
> +			  long mask)
> +{
> +	struct hinge_state *hg_state = iio_priv(indio_dev);
> +	struct hid_sensor_hub_device *hsdev;
> +	int report_id = -1;
> +	int ret_type;
> +	s32 min;
> +
> +	hsdev = hg_group->common_attributes.hsdev;
> +
> +	*val = 0;
> +	*val2 = 0;
> +	switch (mask) {
> +	case IIO_CHAN_INFO_RAW:
> +		hid_sensor_power_state(&hg_group->common_attributes, true);
> +		report_id = hg_state->hinge.report_id;
> +		min = hg_state->hinge.logical_minimum;
> +		if (report_id < 0) {
> +			*val = 0;
> +			hid_sensor_power_state(&hg_group->common_attributes,
> +					       false);
> +			return -EINVAL;
> +		}
> +
> +		*val = sensor_hub_input_attr_get_raw_value(
> +			hg_group->common_attributes.hsdev, hsdev->usage,
> +			hg_state->hinge_address, report_id, SENSOR_HUB_SYNC,
> +			min < 0);
> +
> +		hid_sensor_power_state(&hg_group->common_attributes, false);
> +		ret_type = IIO_VAL_INT;
> +		break;
> +	case IIO_CHAN_INFO_SCALE:
> +		*val = hg_state->scale_pre_decml;
> +		*val2 = hg_state->scale_post_decml;
> +		ret_type = hg_state->scale_precision;
> +		break;
> +	case IIO_CHAN_INFO_OFFSET:
> +		*val = hg_state->value_offset;
> +		ret_type = IIO_VAL_INT;
> +		break;
> +	case IIO_CHAN_INFO_SAMP_FREQ:
> +		ret_type = hid_sensor_read_samp_freq_value(
> +			&hg_group->common_attributes, val, val2);
> +		break;
> +	case IIO_CHAN_INFO_HYSTERESIS:
> +		ret_type = hid_sensor_read_raw_hyst_value(
> +			&hg_group->common_attributes, val, val2);
> +		break;
> +	default:
> +		ret_type = -EINVAL;
> +		break;
> +	}
> +
> +	return ret_type;
> +}
> +
> +/* Channel write_raw handler */
> +static int hinge_write_raw(struct iio_dev *indio_dev,
> +			   struct iio_chan_spec const *chan, int val, int val2,
> +			   long mask)
> +{
> +	int ret;
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_SAMP_FREQ:
> +		ret = hid_sensor_write_samp_freq_value(
> +			&hg_group->common_attributes, val, val2);
> +		break;
> +	case IIO_CHAN_INFO_HYSTERESIS:
> +		ret = hid_sensor_write_raw_hyst_value(
> +			&hg_group->common_attributes, val, val2);
> +
> +		break;
> +	default:
> +		ret = -EINVAL;
> +	}
> +
> +	return ret;
> +}
> +
> +static const struct iio_info hinge_info = {
> +	.read_raw = &hinge_read_raw,
> +	.write_raw = &hinge_write_raw,
> +};
> +
> +/*
> + * Function to push data to buffer;
> + * wrapper added for symmetry with other hid-sensor drivers
> + */
> +static void hid_sensor_push_data(struct iio_dev *indio_dev, void *data, int len,

This doesn't seem to be generic, so don't name it as such.

> +				 int64_t timestamp)
> +{
> +	iio_push_to_buffers_with_timestamp(indio_dev, data, timestamp);
I hope that data buffer obeys the various rules needed by (and admittedly
not that well documented) iio_push_to_buffers_with_timestamp()

1. Needs to be 8 byte aligned.
2. Needs to have space for an aligned 8 byte timestamp at the end.

> +}
> +
> +/*
> + * Callback handler to send event after all samples are received
> + * and captured.
> + */
> +static int hinge_proc_event(struct hid_sensor_hub_device *hsdev,
> +			    unsigned int usage_id, void *priv)
> +{
> +	int i;
> +
> +	for (i = 0; i < IIO_DEV_NUM; ++i) {
If we push for all sensors together, better to have
this as a single iio_device with 3 channels.

Use the channel labels (just added to IIO) to identify which is which.

> +		struct hinge_state *hg_state;
> +		struct iio_dev *indio_dev;
> +
> +		hg_state = hg_group->hg_states[i];
> +		indio_dev = hg_state->indio_dev;
> +
> +		dev_dbg(&indio_dev->dev, "%s timestamp:%llu scan_bytes:%d\n",
> +			__func__, hg_state->timestamp, indio_dev->scan_bytes);
> +
> +		if (!hg_state->timestamp)
> +			hg_state->timestamp = iio_get_time_ns(indio_dev);
> +
> +		hid_sensor_push_data(indio_dev, hg_state->hinge_val,
> +				     sizeof(hg_state->hinge_val),
> +				     hg_state->timestamp);
> +
> +		hg_state->timestamp = 0;
> +	}
> +
> +	return 0;
> +}
> +
> +/* Capture samples in local storage */
> +static int hinge_capture_sample(struct hid_sensor_hub_device *hsdev,
> +				unsigned int usage_id, size_t raw_len,
> +				char *raw_data, void *priv)
> +{
> +	struct hinge_state *hg_state;
> +	int offset;
> +	int ret = -EINVAL;
> +	int i;
> +
> +	if (usage_id == HID_USAGE_SENSOR_TIME_TIMESTAMP) {
> +		for (i = 0; i < IIO_DEV_NUM; i++)
> +			hg_group->hg_states[i]->timestamp =

This rather implies all the data is captured together... If so single
iio_device may make more sense.

> +				hid_sensor_convert_timestamp(
> +					&hg_group->common_attributes,
> +					*(int64_t *)raw_data);
> +		return 0;
> +	}
> +
> +	switch (usage_id) {
> +	case HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_1:
> +	case HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_2:
> +	case HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_3:
> +		offset = usage_id - HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_1;
> +		hg_state = hg_group->hg_states[offset];
> +		hg_state->hinge_val[0] = *(u32 *)raw_data;
> +		ret = 0;

		return 0;

> +		break;
> +	default:
		return -EINVAL;
> +		break;
> +	}
> +
> +	return ret;
> +}
> +
> +/* Parse report which is specific to an usage id */
> +static int hinge_parse_report(struct platform_device *pdev,
> +			      struct hid_sensor_hub_device *hsdev,
> +			      unsigned int usage_id, unsigned int attr_usage_id,
> +			      struct hinge_state *st)
> +{
> +	int ret;
> +
> +	ret = sensor_hub_input_get_attribute_info(
> +		hsdev, HID_INPUT_REPORT, usage_id, attr_usage_id, &st->hinge);
> +	if (ret < 0)
> +		return ret;
> +
> +	st->hinge_address = attr_usage_id;
> +	st->scale_precision =
> +		hid_sensor_format_scale(HID_USAGE_SENSOR_HINGE, &st->hinge,
> +					&st->scale_pre_decml,
> +					&st->scale_post_decml);
> +
> +	/* Set Sensitivity field ids, when there is no individual modifier */
> +	if (hg_group->common_attributes.sensitivity.index < 0) {
> +		sensor_hub_input_get_attribute_info(
> +			hsdev, HID_FEATURE_REPORT, usage_id,
> +			HID_USAGE_SENSOR_DATA_MOD_CHANGE_SENSITIVITY_ABS |
> +				HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_1,
> +			&hg_group->common_attributes.sensitivity);
> +		dev_dbg(&pdev->dev, "Sensitivity index:report %d:%d\n",
> +			hg_group->common_attributes.sensitivity.index,
> +			hg_group->common_attributes.sensitivity.report_id);
> +	}
> +
> +	return ret;
> +}
> +
> +/* Function to initialize the processing for usage id */
> +static int hinge_add_iio_device(struct platform_device *pdev, int index,
> +				const char *name, struct hinge_state **st)
> +{
> +	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
> +	struct hinge_state *hg_state;
> +	struct iio_dev *indio_dev;
> +	int ret;
> +
> +	indio_dev =
> +		devm_iio_device_alloc(&pdev->dev, sizeof(struct hinge_state));

sizeof (*hg_state) preferred.

> +	if (indio_dev == NULL)
> +		return -ENOMEM;
> +
> +	hg_state = iio_priv(indio_dev);
> +	hg_state->indio_dev = indio_dev;
> +
> +	indio_dev->num_channels = ARRAY_SIZE(hinge_channels);
> +	indio_dev->channels =
> +		kmemdup(hinge_channels, sizeof(hinge_channels), GFP_KERNEL);

I don't immediately see anything that is modifying channels. As such you
should be able have it shared by all the instances.

> +	if (!indio_dev->channels)
> +		return -ENOMEM;
> +
> +	ret = hinge_parse_report(
> +		pdev, hsdev, hsdev->usage,
> +		HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_1 + index, hg_state);
> +	if (ret) {
> +		dev_err(&pdev->dev, "failed to setup attributes\n");
> +		goto error_free_dev_mem;
> +	}
> +
> +	indio_dev->dev.parent = &pdev->dev;
> +	indio_dev->info = &hinge_info;
> +	indio_dev->name = name;
> +	indio_dev->modes = INDIO_DIRECT_MODE;
> +
> +	ret = hid_sensor_setup_trigger(indio_dev, name,
> +				       &hg_group->common_attributes);
> +	if (ret < 0) {
> +		dev_err(&pdev->dev, "trigger setup failed\n");
> +		goto error_free_dev_mem;
> +	}
> +
> +	ret = iio_device_register(indio_dev);
> +	if (ret) {
> +		dev_err(&pdev->dev, "device register failed\n");
> +		goto error_remove_trigger;
> +	}
> +
> +	*st = hg_state;
> +
> +	return ret;
> +
> +error_remove_trigger:
> +	hid_sensor_remove_trigger(indio_dev, &hg_group->common_attributes);
> +error_free_dev_mem:
> +	kfree(indio_dev->channels);
> +	return ret;
> +}
> +
> +/* Function to deinitialize the processing for usage id */
> +static int hinge_remove_iio_device(struct platform_device *pdev, int index)
> +{
> +	struct hinge_state *hg_state = hg_group->hg_states[index];
> +	struct iio_dev *indio_dev = hg_state->indio_dev;
> +
> +	iio_device_unregister(indio_dev);
> +	hid_sensor_remove_trigger(indio_dev, &hg_group->common_attributes);
> +	kfree(indio_dev->channels);
> +
> +	return 0;
> +}
> +
> +static int hid_hinge_probe(struct platform_device *pdev)
> +{
> +	struct hinge_state *hg_state;
> +	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
> +	static const char *const names[] = { "hinge", "screen", "keyboard" };
> +	int ret;
> +	int i;
> +
> +	hg_group = devm_kzalloc(&pdev->dev, sizeof(struct hinge_group),
> +				GFP_KERNEL);

As mentioned above, I'd really not expect to see a global like this.
Technically nothing stops there being more than one instance of this
device on a platform (even if that would be a bit odd) + it's almost
always cleaner to not use a global in the first place.

> +	if (!hg_group)
> +		return -ENOMEM;
> +
> +	hg_group->common_attributes.hsdev = hsdev;
> +	hg_group->common_attributes.pdev = pdev;
> +
> +	ret = hid_sensor_parse_common_attributes(hsdev, hsdev->usage,
> +						 &hg_group->common_attributes);
> +	if (ret) {
> +		dev_err(&pdev->dev, "failed to setup common attributes\n");
> +		return ret;
> +	}
> +
> +	atomic_set(&hg_group->common_attributes.data_ready, 0);
> +	for (i = 0; i < IIO_DEV_NUM; i++) {
> +		ret = hinge_add_iio_device(pdev, i, names[i], &hg_state);
> +		if (ret)
> +			goto err_probe;
> +
> +		hg_group->hg_states[i] = hg_state;
> +	}
> +
> +	/* use the first iio device to do the PM */
> +	platform_set_drvdata(pdev, hg_group->hg_states[0]->indio_dev);
> +
> +	hg_group->callbacks.send_event = hinge_proc_event;
> +	hg_group->callbacks.capture_sample = hinge_capture_sample;
> +	hg_group->callbacks.pdev = pdev;
> +	ret = sensor_hub_register_callback(hsdev, hsdev->usage,
> +					   &hg_group->callbacks);
> +	if (ret < 0)
> +		dev_err(&pdev->dev, "callback reg failed\n");
> +
> +	return ret;
> +
> +err_probe:
> +	for (i--; i >= 0; i--)
> +		hinge_remove_iio_device(pdev, i);
> +
> +	return ret;
> +}
> +
> +/* Function to deinitialize the processing for usage id */
> +static int hid_hinge_remove(struct platform_device *pdev)
> +{
> +	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
> +	int i;
> +
> +	sensor_hub_remove_callback(hsdev, hsdev->usage);
> +
> +	for (i = 0; i < IIO_DEV_NUM; i++)
> +		hinge_remove_iio_device(pdev, i);
> +
> +	return 0;
> +}
> +
> +static const struct platform_device_id hid_hinge_ids[] = {
> +	{
> +		/* Format: HID-SENSOR-INT-usage_id_in_hex_lowercase */
> +		.name = "HID-SENSOR-INT-020b",
> +	},
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(platform, hid_hinge_ids);
> +
> +static struct platform_driver hid_hinge_platform_driver = {
> +	.id_table = hid_hinge_ids,
> +	.driver = {
> +		.name	= KBUILD_MODNAME,
> +		.pm	= &hid_sensor_pm_ops,
> +	},
> +	.probe		= hid_hinge_probe,
> +	.remove		= hid_hinge_remove,
> +};
> +module_platform_driver(hid_hinge_platform_driver);
> +
> +MODULE_DESCRIPTION("HID Sensor Custom Hinge");
> +MODULE_AUTHOR("Ye Xiang <xiang.ye@intel.com>");
> +MODULE_LICENSE("GPL");

Pandruvada, Srinivas Nov. 22, 2020, 1:46 a.m. UTC | #2

On Sat, 2020-11-21 at 17:56 +0000, Jonathan Cameron wrote:
> On Thu, 19 Nov 2020 18:03:31 +0800
> Ye Xiang <xiang.ye@intel.com> wrote:
> 
> > The Hinge sensor is a common custom sensor on laptops. It
> > calculates
> > the angle between the lid (screen) and the base (keyboard). In
> > addition,
> > it also exposes screen and the keyboard angels with respect to the
> > ground. Applications can easily get laptop's status in space
> > through
> > this sensor, in order to display appropriate user interface.
> 
> I'm a little unclear on why the 3 axes aren't treated as a single
> sensor.
> You seem to always grab the 3 together or am I missing something?
> 
> That will greatly simplify things and get rid of the need to have
> a shared trigger with the problems that causes in the previous
> patch.

They are not three axes, they are independent. Xiang did try adding x,
y and z component to represent x as hinge, y as keyboard and z as lid.
But I was not convinced.
The problem is that then what will be sysfs interface? They are really
a three sensors. Or we create new interface to call
in_angl_raw_keyboard
in_angl_raw_screen
in_angl_raw_lid.

Thanks,
Srinivas


> 
> Thanks,
> 
> Jonathan
> 
> > Signed-off-by: Ye Xiang <xiang.ye@intel.com>
> > ---
> >  .../hid-sensors/hid-sensor-attributes.c       |   2 +
> >  drivers/iio/position/Kconfig                  |  16 +
> >  drivers/iio/position/Makefile                 |   3 +
> >  .../iio/position/hid-sensor-custom-hinge.c    | 412
> > ++++++++++++++++++
> 
> Given it's custom probably needs a more specific name.  I guess
> hid-sensor-custom-intel-hinge.c might be safe?
> 
> Same for other places we need names in here.
> 
> >  4 files changed, 433 insertions(+)
> >  create mode 100644 drivers/iio/position/hid-sensor-custom-hinge.c
> > 
> > diff --git a/drivers/iio/common/hid-sensors/hid-sensor-attributes.c 
> > b/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> > index 442ff787f7af..5b822a4298a0 100644
> > --- a/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> > +++ b/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> > @@ -71,6 +71,8 @@ static struct {
> >  	{HID_USAGE_SENSOR_TEMPERATURE, HID_USAGE_SENSOR_UNITS_DEGREES,
> > 1000, 0},
> >  
> >  	{HID_USAGE_SENSOR_HUMIDITY, 0, 1000, 0},
> > +	{HID_USAGE_SENSOR_HINGE, 0, 0, 17453293},
> > +	{HID_USAGE_SENSOR_HINGE, HID_USAGE_SENSOR_UNITS_DEGREES, 0,
> > 17453293},
> >  };
> >  
> >  static void simple_div(int dividend, int divisor, int *whole,
> > diff --git a/drivers/iio/position/Kconfig
> > b/drivers/iio/position/Kconfig
> > index eda67f008c5b..0346f6f2b422 100644
> > --- a/drivers/iio/position/Kconfig
> > +++ b/drivers/iio/position/Kconfig
> > @@ -16,4 +16,20 @@ config IQS624_POS
> >  	  To compile this driver as a module, choose M here: the module
> >  	  will be called iqs624-pos.
> >  
> > +config HID_SENSOR_CUSTOM_HINGE
> > +	depends on HID_SENSOR_HUB
> > +	select IIO_BUFFER
> > +	select IIO_TRIGGERED_BUFFER
> > +	select HID_SENSOR_IIO_COMMON
> > +	select HID_SENSOR_IIO_TRIGGER
> > +	tristate "HID Hinge"
> > +	help
> > +	  This sensor present three angles, hinge angel, screen angles
> > +	  and keyboard angle respect to horizon (ground).
> > +	  Say yes here to build support for the HID SENSOR CUSTOM
> > +	  HINGE.
> 
> Capitalization is a bit odd looking. I'd drop it.
> 
> > +
> > +	  To compile this driver as a module, choose M here: the
> > +	  module will be called hid-sensor-custom-hinge.
> > +
> >  endmenu
> > diff --git a/drivers/iio/position/Makefile
> > b/drivers/iio/position/Makefile
> > index 3cbe7a734352..7a6225977a01 100644
> > --- a/drivers/iio/position/Makefile
> > +++ b/drivers/iio/position/Makefile
> > @@ -5,3 +5,6 @@
> >  # When adding new entries keep the list in alphabetical order
> >  
> >  obj-$(CONFIG_IQS624_POS)	+= iqs624-pos.o
> > +
> > +obj-$(CONFIG_HID_SENSOR_CUSTOM_HINGE) += hid-sensor-custom-hinge.o
> 
> Alphabetical order preferred.
> 
> > +ccflags-y	+= -I$(srctree)/drivers/iio/common/hid-sensors
> 
> Why?
> 
> > diff --git a/drivers/iio/position/hid-sensor-custom-hinge.c
> > b/drivers/iio/position/hid-sensor-custom-hinge.c
> > new file mode 100644
> > index 000000000000..a91b333f36fa
> > --- /dev/null
> > +++ b/drivers/iio/position/hid-sensor-custom-hinge.c
> > @@ -0,0 +1,412 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +/*
> > + * HID Sensors Driver
> > + * Copyright (c) 2020, Intel Corporation.
> > + */
> > +#include <linux/hid-sensor-hub.h>
> > +#include <linux/iio/buffer.h>
> > +#include <linux/iio/iio.h>
> > +#include <linux/platform_device.h>
> > +
> > +#include "hid-sensor-trigger.h"
> > +
> > +/* Channel definitions */
> > +static const struct iio_chan_spec hinge_channels[] = {
> > +	{ .type = IIO_ANGL,
> > +	  .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> > +	  .info_mask_shared_by_type =
> > +		  BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_SCALE)
> > |
> > +		  BIT(IIO_CHAN_INFO_SAMP_FREQ) |
> > BIT(IIO_CHAN_INFO_HYSTERESIS),
> > +	  .scan_type.realbits = 16,
> > +	  .scan_type.storagebits = 32,
> 
> It a bit odd to see a single channel that is 16 bits inside a 32 bit
> with
> no shift or similar.  Why not just pack it into 16 bits?
> 
> > +	  .scan_type.sign = 's',
> > +	  .scan_index = 0 },
> > +
> > +	IIO_CHAN_SOFT_TIMESTAMP(1)
> > +};
> > +
> > +struct hinge_state {
> > +	struct iio_dev *indio_dev;
> > +	struct hid_sensor_hub_attribute_info hinge;
> > +	/* Reserve for 1 channel + pading + timestamp */
> > +	u32 hinge_val[1 + 3];
> 
> __aligned(8)
> 
> see below for requirements on this.
> Perhaps better to use
> 
> 	struct hinge_scan {
> 		u32 val;
> 		s64 timestamp __aligned(8); // Note this is needed for
> x86_32
> 	} scan;
> 
> > +	int scale_pre_decml;
> > +	int scale_post_decml;
> > +	int scale_precision;
> > +	int value_offset;
> > +	int64_t timestamp;
> > +	u32 hinge_address;
> > +};
> > +
> > +#define IIO_DEV_NUM 3
> 
> That needs a prefix to make it clear it's not a generic constant
> but is specific to this driver.
> 
> > +
> > +struct hinge_group {
> > +	struct hinge_state *hg_states[IIO_DEV_NUM];
> > +	struct hid_sensor_hub_callbacks callbacks;
> > +	struct hid_sensor_common common_attributes;
> > +};
> > +
> > +static struct hinge_group *hg_group;
> 
> We shouldn't see globals like this. Please figure out how to avoid
> it.
> 
> > +
> > +/* Channel read_raw handler */
> > +static int hinge_read_raw(struct iio_dev *indio_dev,
> > +			  struct iio_chan_spec const *chan, int *val,
> > int *val2,
> > +			  long mask)
> > +{
> > +	struct hinge_state *hg_state = iio_priv(indio_dev);
> > +	struct hid_sensor_hub_device *hsdev;
> > +	int report_id = -1;
> > +	int ret_type;
> > +	s32 min;
> > +
> > +	hsdev = hg_group->common_attributes.hsdev;
> > +
> > +	*val = 0;
> > +	*val2 = 0;
> > +	switch (mask) {
> > +	case IIO_CHAN_INFO_RAW:
> > +		hid_sensor_power_state(&hg_group->common_attributes,
> > true);
> > +		report_id = hg_state->hinge.report_id;
> > +		min = hg_state->hinge.logical_minimum;
> > +		if (report_id < 0) {
> > +			*val = 0;
> > +			hid_sensor_power_state(&hg_group-
> > >common_attributes,
> > +					       false);
> > +			return -EINVAL;
> > +		}
> > +
> > +		*val = sensor_hub_input_attr_get_raw_value(
> > +			hg_group->common_attributes.hsdev, hsdev-
> > >usage,
> > +			hg_state->hinge_address, report_id,
> > SENSOR_HUB_SYNC,
> > +			min < 0);
> > +
> > +		hid_sensor_power_state(&hg_group->common_attributes,
> > false);
> > +		ret_type = IIO_VAL_INT;
> > +		break;
> > +	case IIO_CHAN_INFO_SCALE:
> > +		*val = hg_state->scale_pre_decml;
> > +		*val2 = hg_state->scale_post_decml;
> > +		ret_type = hg_state->scale_precision;
> > +		break;
> > +	case IIO_CHAN_INFO_OFFSET:
> > +		*val = hg_state->value_offset;
> > +		ret_type = IIO_VAL_INT;
> > +		break;
> > +	case IIO_CHAN_INFO_SAMP_FREQ:
> > +		ret_type = hid_sensor_read_samp_freq_value(
> > +			&hg_group->common_attributes, val, val2);
> > +		break;
> > +	case IIO_CHAN_INFO_HYSTERESIS:
> > +		ret_type = hid_sensor_read_raw_hyst_value(
> > +			&hg_group->common_attributes, val, val2);
> > +		break;
> > +	default:
> > +		ret_type = -EINVAL;
> > +		break;
> > +	}
> > +
> > +	return ret_type;
> > +}
> > +
> > +/* Channel write_raw handler */
> > +static int hinge_write_raw(struct iio_dev *indio_dev,
> > +			   struct iio_chan_spec const *chan, int val,
> > int val2,
> > +			   long mask)
> > +{
> > +	int ret;
> > +
> > +	switch (mask) {
> > +	case IIO_CHAN_INFO_SAMP_FREQ:
> > +		ret = hid_sensor_write_samp_freq_value(
> > +			&hg_group->common_attributes, val, val2);
> > +		break;
> > +	case IIO_CHAN_INFO_HYSTERESIS:
> > +		ret = hid_sensor_write_raw_hyst_value(
> > +			&hg_group->common_attributes, val, val2);
> > +
> > +		break;
> > +	default:
> > +		ret = -EINVAL;
> > +	}
> > +
> > +	return ret;
> > +}
> > +
> > +static const struct iio_info hinge_info = {
> > +	.read_raw = &hinge_read_raw,
> > +	.write_raw = &hinge_write_raw,
> > +};
> > +
> > +/*
> > + * Function to push data to buffer;
> > + * wrapper added for symmetry with other hid-sensor drivers
> > + */
> > +static void hid_sensor_push_data(struct iio_dev *indio_dev, void
> > *data, int len,
> 
> This doesn't seem to be generic, so don't name it as such.
> 
> > +				 int64_t timestamp)
> > +{
> > +	iio_push_to_buffers_with_timestamp(indio_dev, data, timestamp);
> I hope that data buffer obeys the various rules needed by (and
> admittedly
> not that well documented) iio_push_to_buffers_with_timestamp()
> 
> 1. Needs to be 8 byte aligned.
> 2. Needs to have space for an aligned 8 byte timestamp at the end.
> 
> > +}
> > +
> > +/*
> > + * Callback handler to send event after all samples are received
> > + * and captured.
> > + */
> > +static int hinge_proc_event(struct hid_sensor_hub_device *hsdev,
> > +			    unsigned int usage_id, void *priv)
> > +{
> > +	int i;
> > +
> > +	for (i = 0; i < IIO_DEV_NUM; ++i) {
> If we push for all sensors together, better to have
> this as a single iio_device with 3 channels.
> 
> Use the channel labels (just added to IIO) to identify which is
> which.
> 
> > +		struct hinge_state *hg_state;
> > +		struct iio_dev *indio_dev;
> > +
> > +		hg_state = hg_group->hg_states[i];
> > +		indio_dev = hg_state->indio_dev;
> > +
> > +		dev_dbg(&indio_dev->dev, "%s timestamp:%llu
> > scan_bytes:%d\n",
> > +			__func__, hg_state->timestamp, indio_dev-
> > >scan_bytes);
> > +
> > +		if (!hg_state->timestamp)
> > +			hg_state->timestamp =
> > iio_get_time_ns(indio_dev);
> > +
> > +		hid_sensor_push_data(indio_dev, hg_state->hinge_val,
> > +				     sizeof(hg_state->hinge_val),
> > +				     hg_state->timestamp);
> > +
> > +		hg_state->timestamp = 0;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +/* Capture samples in local storage */
> > +static int hinge_capture_sample(struct hid_sensor_hub_device
> > *hsdev,
> > +				unsigned int usage_id, size_t raw_len,
> > +				char *raw_data, void *priv)
> > +{
> > +	struct hinge_state *hg_state;
> > +	int offset;
> > +	int ret = -EINVAL;
> > +	int i;
> > +
> > +	if (usage_id == HID_USAGE_SENSOR_TIME_TIMESTAMP) {
> > +		for (i = 0; i < IIO_DEV_NUM; i++)
> > +			hg_group->hg_states[i]->timestamp =
> 
> This rather implies all the data is captured together... If so single
> iio_device may make more sense.
> 
> > +				hid_sensor_convert_timestamp(
> > +					&hg_group->common_attributes,
> > +					*(int64_t *)raw_data);
> > +		return 0;
> > +	}
> > +
> > +	switch (usage_id) {
> > +	case HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_1:
> > +	case HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_2:
> > +	case HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_3:
> > +		offset = usage_id -
> > HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_1;
> > +		hg_state = hg_group->hg_states[offset];
> > +		hg_state->hinge_val[0] = *(u32 *)raw_data;
> > +		ret = 0;
> 
> 		return 0;
> 
> > +		break;
> > +	default:
> 		return -EINVAL;
> > +		break;
> > +	}
> > +
> > +	return ret;
> > +}
> > +
> > +/* Parse report which is specific to an usage id */
> > +static int hinge_parse_report(struct platform_device *pdev,
> > +			      struct hid_sensor_hub_device *hsdev,
> > +			      unsigned int usage_id, unsigned int
> > attr_usage_id,
> > +			      struct hinge_state *st)
> > +{
> > +	int ret;
> > +
> > +	ret = sensor_hub_input_get_attribute_info(
> > +		hsdev, HID_INPUT_REPORT, usage_id, attr_usage_id, &st-
> > >hinge);
> > +	if (ret < 0)
> > +		return ret;
> > +
> > +	st->hinge_address = attr_usage_id;
> > +	st->scale_precision =
> > +		hid_sensor_format_scale(HID_USAGE_SENSOR_HINGE, &st-
> > >hinge,
> > +					&st->scale_pre_decml,
> > +					&st->scale_post_decml);
> > +
> > +	/* Set Sensitivity field ids, when there is no individual
> > modifier */
> > +	if (hg_group->common_attributes.sensitivity.index < 0) {
> > +		sensor_hub_input_get_attribute_info(
> > +			hsdev, HID_FEATURE_REPORT, usage_id,
> > +			HID_USAGE_SENSOR_DATA_MOD_CHANGE_SENSITIVITY_AB
> > S |
> > +				HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALU
> > E_1,
> > +			&hg_group->common_attributes.sensitivity);
> > +		dev_dbg(&pdev->dev, "Sensitivity index:report %d:%d\n",
> > +			hg_group->common_attributes.sensitivity.index,
> > +			hg_group-
> > >common_attributes.sensitivity.report_id);
> > +	}
> > +
> > +	return ret;
> > +}
> > +
> > +/* Function to initialize the processing for usage id */
> > +static int hinge_add_iio_device(struct platform_device *pdev, int
> > index,
> > +				const char *name, struct hinge_state
> > **st)
> > +{
> > +	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
> > +	struct hinge_state *hg_state;
> > +	struct iio_dev *indio_dev;
> > +	int ret;
> > +
> > +	indio_dev =
> > +		devm_iio_device_alloc(&pdev->dev, sizeof(struct
> > hinge_state));
> 
> sizeof (*hg_state) preferred.
> 
> > +	if (indio_dev == NULL)
> > +		return -ENOMEM;
> > +
> > +	hg_state = iio_priv(indio_dev);
> > +	hg_state->indio_dev = indio_dev;
> > +
> > +	indio_dev->num_channels = ARRAY_SIZE(hinge_channels);
> > +	indio_dev->channels =
> > +		kmemdup(hinge_channels, sizeof(hinge_channels),
> > GFP_KERNEL);
> 
> I don't immediately see anything that is modifying channels. As such
> you
> should be able have it shared by all the instances.
> 
> > +	if (!indio_dev->channels)
> > +		return -ENOMEM;
> > +
> > +	ret = hinge_parse_report(
> > +		pdev, hsdev, hsdev->usage,
> > +		HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_1 + index,
> > hg_state);
> > +	if (ret) {
> > +		dev_err(&pdev->dev, "failed to setup attributes\n");
> > +		goto error_free_dev_mem;
> > +	}
> > +
> > +	indio_dev->dev.parent = &pdev->dev;
> > +	indio_dev->info = &hinge_info;
> > +	indio_dev->name = name;
> > +	indio_dev->modes = INDIO_DIRECT_MODE;
> > +
> > +	ret = hid_sensor_setup_trigger(indio_dev, name,
> > +				       &hg_group->common_attributes);
> > +	if (ret < 0) {
> > +		dev_err(&pdev->dev, "trigger setup failed\n");
> > +		goto error_free_dev_mem;
> > +	}
> > +
> > +	ret = iio_device_register(indio_dev);
> > +	if (ret) {
> > +		dev_err(&pdev->dev, "device register failed\n");
> > +		goto error_remove_trigger;
> > +	}
> > +
> > +	*st = hg_state;
> > +
> > +	return ret;
> > +
> > +error_remove_trigger:
> > +	hid_sensor_remove_trigger(indio_dev, &hg_group-
> > >common_attributes);
> > +error_free_dev_mem:
> > +	kfree(indio_dev->channels);
> > +	return ret;
> > +}
> > +
> > +/* Function to deinitialize the processing for usage id */
> > +static int hinge_remove_iio_device(struct platform_device *pdev,
> > int index)
> > +{
> > +	struct hinge_state *hg_state = hg_group->hg_states[index];
> > +	struct iio_dev *indio_dev = hg_state->indio_dev;
> > +
> > +	iio_device_unregister(indio_dev);
> > +	hid_sensor_remove_trigger(indio_dev, &hg_group-
> > >common_attributes);
> > +	kfree(indio_dev->channels);
> > +
> > +	return 0;
> > +}
> > +
> > +static int hid_hinge_probe(struct platform_device *pdev)
> > +{
> > +	struct hinge_state *hg_state;
> > +	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
> > +	static const char *const names[] = { "hinge", "screen",
> > "keyboard" };
> > +	int ret;
> > +	int i;
> > +
> > +	hg_group = devm_kzalloc(&pdev->dev, sizeof(struct hinge_group),
> > +				GFP_KERNEL);
> 
> As mentioned above, I'd really not expect to see a global like this.
> Technically nothing stops there being more than one instance of this
> device on a platform (even if that would be a bit odd) + it's almost
> always cleaner to not use a global in the first place.
> 
> > +	if (!hg_group)
> > +		return -ENOMEM;
> > +
> > +	hg_group->common_attributes.hsdev = hsdev;
> > +	hg_group->common_attributes.pdev = pdev;
> > +
> > +	ret = hid_sensor_parse_common_attributes(hsdev, hsdev->usage,
> > +						 &hg_group-
> > >common_attributes);
> > +	if (ret) {
> > +		dev_err(&pdev->dev, "failed to setup common
> > attributes\n");
> > +		return ret;
> > +	}
> > +
> > +	atomic_set(&hg_group->common_attributes.data_ready, 0);
> > +	for (i = 0; i < IIO_DEV_NUM; i++) {
> > +		ret = hinge_add_iio_device(pdev, i, names[i],
> > &hg_state);
> > +		if (ret)
> > +			goto err_probe;
> > +
> > +		hg_group->hg_states[i] = hg_state;
> > +	}
> > +
> > +	/* use the first iio device to do the PM */
> > +	platform_set_drvdata(pdev, hg_group->hg_states[0]->indio_dev);
> > +
> > +	hg_group->callbacks.send_event = hinge_proc_event;
> > +	hg_group->callbacks.capture_sample = hinge_capture_sample;
> > +	hg_group->callbacks.pdev = pdev;
> > +	ret = sensor_hub_register_callback(hsdev, hsdev->usage,
> > +					   &hg_group->callbacks);
> > +	if (ret < 0)
> > +		dev_err(&pdev->dev, "callback reg failed\n");
> > +
> > +	return ret;
> > +
> > +err_probe:
> > +	for (i--; i >= 0; i--)
> > +		hinge_remove_iio_device(pdev, i);
> > +
> > +	return ret;
> > +}
> > +
> > +/* Function to deinitialize the processing for usage id */
> > +static int hid_hinge_remove(struct platform_device *pdev)
> > +{
> > +	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
> > +	int i;
> > +
> > +	sensor_hub_remove_callback(hsdev, hsdev->usage);
> > +
> > +	for (i = 0; i < IIO_DEV_NUM; i++)
> > +		hinge_remove_iio_device(pdev, i);
> > +
> > +	return 0;
> > +}
> > +
> > +static const struct platform_device_id hid_hinge_ids[] = {
> > +	{
> > +		/* Format: HID-SENSOR-INT-usage_id_in_hex_lowercase */
> > +		.name = "HID-SENSOR-INT-020b",
> > +	},
> > +	{ /* sentinel */ }
> > +};
> > +MODULE_DEVICE_TABLE(platform, hid_hinge_ids);
> > +
> > +static struct platform_driver hid_hinge_platform_driver = {
> > +	.id_table = hid_hinge_ids,
> > +	.driver = {
> > +		.name	= KBUILD_MODNAME,
> > +		.pm	= &hid_sensor_pm_ops,
> > +	},
> > +	.probe		= hid_hinge_probe,
> > +	.remove		= hid_hinge_remove,
> > +};
> > +module_platform_driver(hid_hinge_platform_driver);
> > +
> > +MODULE_DESCRIPTION("HID Sensor Custom Hinge");
> > +MODULE_AUTHOR("Ye Xiang <xiang.ye@intel.com>");
> > +MODULE_LICENSE("GPL");

Pandruvada, Srinivas Nov. 22, 2020, 2:14 a.m. UTC | #3

On Sat, 2020-11-21 at 17:46 -0800, Srinivas Pandruvada wrote:
> On Sat, 2020-11-21 at 17:56 +0000, Jonathan Cameron wrote:
> > On Thu, 19 Nov 2020 18:03:31 +0800
> > Ye Xiang <xiang.ye@intel.com> wrote:
> > 
> > > The Hinge sensor is a common custom sensor on laptops. It
> > > calculates
> > > the angle between the lid (screen) and the base (keyboard). In
> > > addition,
> > > it also exposes screen and the keyboard angels with respect to
> > > the
> > > ground. Applications can easily get laptop's status in space
> > > through
> > > this sensor, in order to display appropriate user interface.
> > 
> > I'm a little unclear on why the 3 axes aren't treated as a single
> > sensor.
> > You seem to always grab the 3 together or am I missing something?
> > 
> > That will greatly simplify things and get rid of the need to have
> > a shared trigger with the problems that causes in the previous
> > patch.
> 
> They are not three axes, they are independent. Xiang did try adding
> x,
> y and z component to represent x as hinge, y as keyboard and z as
> lid.
> But I was not convinced.
> The problem is that then what will be sysfs interface? They are
> really
> a three sensors. Or we create new interface to call
> in_angl_raw_keyboard
> in_angl_raw_screen
> in_angl_raw_lid.
> 
You seem to indicate this is possible now some new "label" patch.
Is this the patch?
commit 2c3d0c9ffd24d9b4c62c5dfb2104695a614be28c
Author: Phil Reid <preid@electromag.com.au>
Date:   Thu Sep 19 22:36:08 2019 +0800

Ideally, one iio device here is much easy to manage as other HID
sensors. If we can add something other that "x", "y" and "z" component.

Thanks,
Srinivas

> Thanks,
> Srinivas
> 
> 
> > Thanks,
> > 
> > Jonathan
> > 
> > > Signed-off-by: Ye Xiang <xiang.ye@intel.com>
> > > ---
> > >  .../hid-sensors/hid-sensor-attributes.c       |   2 +
> > >  drivers/iio/position/Kconfig                  |  16 +
> > >  drivers/iio/position/Makefile                 |   3 +
> > >  .../iio/position/hid-sensor-custom-hinge.c    | 412
> > > ++++++++++++++++++
> > 
> > Given it's custom probably needs a more specific name.  I guess
> > hid-sensor-custom-intel-hinge.c might be safe?
> > 
> > Same for other places we need names in here.
> > 
> > >  4 files changed, 433 insertions(+)
> > >  create mode 100644 drivers/iio/position/hid-sensor-custom-
> > > hinge.c
> > > 
> > > diff --git a/drivers/iio/common/hid-sensors/hid-sensor-
> > > attributes.c 
> > > b/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> > > index 442ff787f7af..5b822a4298a0 100644
> > > --- a/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> > > +++ b/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> > > @@ -71,6 +71,8 @@ static struct {
> > >  	{HID_USAGE_SENSOR_TEMPERATURE, HID_USAGE_SENSOR_UNITS_DEGREES,
> > > 1000, 0},
> > >  
> > >  	{HID_USAGE_SENSOR_HUMIDITY, 0, 1000, 0},
> > > +	{HID_USAGE_SENSOR_HINGE, 0, 0, 17453293},
> > > +	{HID_USAGE_SENSOR_HINGE, HID_USAGE_SENSOR_UNITS_DEGREES, 0,
> > > 17453293},
> > >  };
> > >  
> > >  static void simple_div(int dividend, int divisor, int *whole,
> > > diff --git a/drivers/iio/position/Kconfig
> > > b/drivers/iio/position/Kconfig
> > > index eda67f008c5b..0346f6f2b422 100644
> > > --- a/drivers/iio/position/Kconfig
> > > +++ b/drivers/iio/position/Kconfig
> > > @@ -16,4 +16,20 @@ config IQS624_POS
> > >  	  To compile this driver as a module, choose M here: the module
> > >  	  will be called iqs624-pos.
> > >  
> > > +config HID_SENSOR_CUSTOM_HINGE
> > > +	depends on HID_SENSOR_HUB
> > > +	select IIO_BUFFER
> > > +	select IIO_TRIGGERED_BUFFER
> > > +	select HID_SENSOR_IIO_COMMON
> > > +	select HID_SENSOR_IIO_TRIGGER
> > > +	tristate "HID Hinge"
> > > +	help
> > > +	  This sensor present three angles, hinge angel, screen angles
> > > +	  and keyboard angle respect to horizon (ground).
> > > +	  Say yes here to build support for the HID SENSOR CUSTOM
> > > +	  HINGE.
> > 
> > Capitalization is a bit odd looking. I'd drop it.
> > 
> > > +
> > > +	  To compile this driver as a module, choose M here: the
> > > +	  module will be called hid-sensor-custom-hinge.
> > > +
> > >  endmenu
> > > diff --git a/drivers/iio/position/Makefile
> > > b/drivers/iio/position/Makefile
> > > index 3cbe7a734352..7a6225977a01 100644
> > > --- a/drivers/iio/position/Makefile
> > > +++ b/drivers/iio/position/Makefile
> > > @@ -5,3 +5,6 @@
> > >  # When adding new entries keep the list in alphabetical order
> > >  
> > >  obj-$(CONFIG_IQS624_POS)	+= iqs624-pos.o
> > > +
> > > +obj-$(CONFIG_HID_SENSOR_CUSTOM_HINGE) += hid-sensor-custom-
> > > hinge.o
> > 
> > Alphabetical order preferred.
> > 
> > > +ccflags-y	+= -I$(srctree)/drivers/iio/common/hid-sensors
> > 
> > Why?
> > 
> > > diff --git a/drivers/iio/position/hid-sensor-custom-hinge.c
> > > b/drivers/iio/position/hid-sensor-custom-hinge.c
> > > new file mode 100644
> > > index 000000000000..a91b333f36fa
> > > --- /dev/null
> > > +++ b/drivers/iio/position/hid-sensor-custom-hinge.c
> > > @@ -0,0 +1,412 @@
> > > +// SPDX-License-Identifier: GPL-2.0-only
> > > +/*
> > > + * HID Sensors Driver
> > > + * Copyright (c) 2020, Intel Corporation.
> > > + */
> > > +#include <linux/hid-sensor-hub.h>
> > > +#include <linux/iio/buffer.h>
> > > +#include <linux/iio/iio.h>
> > > +#include <linux/platform_device.h>
> > > +
> > > +#include "hid-sensor-trigger.h"
> > > +
> > > +/* Channel definitions */
> > > +static const struct iio_chan_spec hinge_channels[] = {
> > > +	{ .type = IIO_ANGL,
> > > +	  .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> > > +	  .info_mask_shared_by_type =
> > > +		  BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_SCALE)
> > > +		  BIT(IIO_CHAN_INFO_SAMP_FREQ) |
> > > BIT(IIO_CHAN_INFO_HYSTERESIS),
> > > +	  .scan_type.realbits = 16,
> > > +	  .scan_type.storagebits = 32,
> > 
> > It a bit odd to see a single channel that is 16 bits inside a 32
> > bit
> > with
> > no shift or similar.  Why not just pack it into 16 bits?
> > 
> > > +	  .scan_type.sign = 's',
> > > +	  .scan_index = 0 },
> > > +
> > > +	IIO_CHAN_SOFT_TIMESTAMP(1)
> > > +};
> > > +
> > > +struct hinge_state {
> > > +	struct iio_dev *indio_dev;
> > > +	struct hid_sensor_hub_attribute_info hinge;
> > > +	/* Reserve for 1 channel + pading + timestamp */
> > > +	u32 hinge_val[1 + 3];
> > 
> > __aligned(8)
> > 
> > see below for requirements on this.
> > Perhaps better to use
> > 
> > 	struct hinge_scan {
> > 		u32 val;
> > 		s64 timestamp __aligned(8); // Note this is needed for
> > x86_32
> > 	} scan;
> > 
> > > +	int scale_pre_decml;
> > > +	int scale_post_decml;
> > > +	int scale_precision;
> > > +	int value_offset;
> > > +	int64_t timestamp;
> > > +	u32 hinge_address;
> > > +};
> > > +
> > > +#define IIO_DEV_NUM 3
> > 
> > That needs a prefix to make it clear it's not a generic constant
> > but is specific to this driver.
> > 
> > > +
> > > +struct hinge_group {
> > > +	struct hinge_state *hg_states[IIO_DEV_NUM];
> > > +	struct hid_sensor_hub_callbacks callbacks;
> > > +	struct hid_sensor_common common_attributes;
> > > +};
> > > +
> > > +static struct hinge_group *hg_group;
> > 
> > We shouldn't see globals like this. Please figure out how to avoid
> > it.
> > 
> > > +
> > > +/* Channel read_raw handler */
> > > +static int hinge_read_raw(struct iio_dev *indio_dev,
> > > +			  struct iio_chan_spec const *chan, int *val,
> > > int *val2,
> > > +			  long mask)
> > > +{
> > > +	struct hinge_state *hg_state = iio_priv(indio_dev);
> > > +	struct hid_sensor_hub_device *hsdev;
> > > +	int report_id = -1;
> > > +	int ret_type;
> > > +	s32 min;
> > > +
> > > +	hsdev = hg_group->common_attributes.hsdev;
> > > +
> > > +	*val = 0;
> > > +	*val2 = 0;
> > > +	switch (mask) {
> > > +	case IIO_CHAN_INFO_RAW:
> > > +		hid_sensor_power_state(&hg_group->common_attributes,
> > > true);
> > > +		report_id = hg_state->hinge.report_id;
> > > +		min = hg_state->hinge.logical_minimum;
> > > +		if (report_id < 0) {
> > > +			*val = 0;
> > > +			hid_sensor_power_state(&hg_group-
> > > > common_attributes,
> > > +					       false);
> > > +			return -EINVAL;
> > > +		}
> > > +
> > > +		*val = sensor_hub_input_attr_get_raw_value(
> > > +			hg_group->common_attributes.hsdev, hsdev-
> > > > usage,
> > > +			hg_state->hinge_address, report_id,
> > > SENSOR_HUB_SYNC,
> > > +			min < 0);
> > > +
> > > +		hid_sensor_power_state(&hg_group->common_attributes,
> > > false);
> > > +		ret_type = IIO_VAL_INT;
> > > +		break;
> > > +	case IIO_CHAN_INFO_SCALE:
> > > +		*val = hg_state->scale_pre_decml;
> > > +		*val2 = hg_state->scale_post_decml;
> > > +		ret_type = hg_state->scale_precision;
> > > +		break;
> > > +	case IIO_CHAN_INFO_OFFSET:
> > > +		*val = hg_state->value_offset;
> > > +		ret_type = IIO_VAL_INT;
> > > +		break;
> > > +	case IIO_CHAN_INFO_SAMP_FREQ:
> > > +		ret_type = hid_sensor_read_samp_freq_value(
> > > +			&hg_group->common_attributes, val, val2);
> > > +		break;
> > > +	case IIO_CHAN_INFO_HYSTERESIS:
> > > +		ret_type = hid_sensor_read_raw_hyst_value(
> > > +			&hg_group->common_attributes, val, val2);
> > > +		break;
> > > +	default:
> > > +		ret_type = -EINVAL;
> > > +		break;
> > > +	}
> > > +
> > > +	return ret_type;
> > > +}
> > > +
> > > +/* Channel write_raw handler */
> > > +static int hinge_write_raw(struct iio_dev *indio_dev,
> > > +			   struct iio_chan_spec const *chan, int val,
> > > int val2,
> > > +			   long mask)
> > > +{
> > > +	int ret;
> > > +
> > > +	switch (mask) {
> > > +	case IIO_CHAN_INFO_SAMP_FREQ:
> > > +		ret = hid_sensor_write_samp_freq_value(
> > > +			&hg_group->common_attributes, val, val2);
> > > +		break;
> > > +	case IIO_CHAN_INFO_HYSTERESIS:
> > > +		ret = hid_sensor_write_raw_hyst_value(
> > > +			&hg_group->common_attributes, val, val2);
> > > +
> > > +		break;
> > > +	default:
> > > +		ret = -EINVAL;
> > > +	}
> > > +
> > > +	return ret;
> > > +}
> > > +
> > > +static const struct iio_info hinge_info = {
> > > +	.read_raw = &hinge_read_raw,
> > > +	.write_raw = &hinge_write_raw,
> > > +};
> > > +
> > > +/*
> > > + * Function to push data to buffer;
> > > + * wrapper added for symmetry with other hid-sensor drivers
> > > + */
> > > +static void hid_sensor_push_data(struct iio_dev *indio_dev, void
> > > *data, int len,
> > 
> > This doesn't seem to be generic, so don't name it as such.
> > 
> > > +				 int64_t timestamp)
> > > +{
> > > +	iio_push_to_buffers_with_timestamp(indio_dev, data, timestamp);
> > I hope that data buffer obeys the various rules needed by (and
> > admittedly
> > not that well documented) iio_push_to_buffers_with_timestamp()
> > 
> > 1. Needs to be 8 byte aligned.
> > 2. Needs to have space for an aligned 8 byte timestamp at the end.
> > 
> > > +}
> > > +
> > > +/*
> > > + * Callback handler to send event after all samples are received
> > > + * and captured.
> > > + */
> > > +static int hinge_proc_event(struct hid_sensor_hub_device *hsdev,
> > > +			    unsigned int usage_id, void *priv)
> > > +{
> > > +	int i;
> > > +
> > > +	for (i = 0; i < IIO_DEV_NUM; ++i) {
> > If we push for all sensors together, better to have
> > this as a single iio_device with 3 channels.
> > 
> > Use the channel labels (just added to IIO) to identify which is
> > which.
> > 
> > > +		struct hinge_state *hg_state;
> > > +		struct iio_dev *indio_dev;
> > > +
> > > +		hg_state = hg_group->hg_states[i];
> > > +		indio_dev = hg_state->indio_dev;
> > > +
> > > +		dev_dbg(&indio_dev->dev, "%s timestamp:%llu
> > > scan_bytes:%d\n",
> > > +			__func__, hg_state->timestamp, indio_dev-
> > > > scan_bytes);
> > > +
> > > +		if (!hg_state->timestamp)
> > > +			hg_state->timestamp =
> > > iio_get_time_ns(indio_dev);
> > > +
> > > +		hid_sensor_push_data(indio_dev, hg_state->hinge_val,
> > > +				     sizeof(hg_state->hinge_val),
> > > +				     hg_state->timestamp);
> > > +
> > > +		hg_state->timestamp = 0;
> > > +	}
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +/* Capture samples in local storage */
> > > +static int hinge_capture_sample(struct hid_sensor_hub_device
> > > *hsdev,
> > > +				unsigned int usage_id, size_t raw_len,
> > > +				char *raw_data, void *priv)
> > > +{
> > > +	struct hinge_state *hg_state;
> > > +	int offset;
> > > +	int ret = -EINVAL;
> > > +	int i;
> > > +
> > > +	if (usage_id == HID_USAGE_SENSOR_TIME_TIMESTAMP) {
> > > +		for (i = 0; i < IIO_DEV_NUM; i++)
> > > +			hg_group->hg_states[i]->timestamp =
> > 
> > This rather implies all the data is captured together... If so
> > single
> > iio_device may make more sense.
> > 
> > > +				hid_sensor_convert_timestamp(
> > > +					&hg_group->common_attributes,
> > > +					*(int64_t *)raw_data);
> > > +		return 0;
> > > +	}
> > > +
> > > +	switch (usage_id) {
> > > +	case HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_1:
> > > +	case HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_2:
> > > +	case HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_3:
> > > +		offset = usage_id -
> > > HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_1;
> > > +		hg_state = hg_group->hg_states[offset];
> > > +		hg_state->hinge_val[0] = *(u32 *)raw_data;
> > > +		ret = 0;
> > 
> > 		return 0;
> > 
> > > +		break;
> > > +	default:
> > 		return -EINVAL;
> > > +		break;
> > > +	}
> > > +
> > > +	return ret;
> > > +}
> > > +
> > > +/* Parse report which is specific to an usage id */
> > > +static int hinge_parse_report(struct platform_device *pdev,
> > > +			      struct hid_sensor_hub_device *hsdev,
> > > +			      unsigned int usage_id, unsigned int
> > > attr_usage_id,
> > > +			      struct hinge_state *st)
> > > +{
> > > +	int ret;
> > > +
> > > +	ret = sensor_hub_input_get_attribute_info(
> > > +		hsdev, HID_INPUT_REPORT, usage_id, attr_usage_id, &st-
> > > > hinge);
> > > +	if (ret < 0)
> > > +		return ret;
> > > +
> > > +	st->hinge_address = attr_usage_id;
> > > +	st->scale_precision =
> > > +		hid_sensor_format_scale(HID_USAGE_SENSOR_HINGE, &st-
> > > > hinge,
> > > +					&st->scale_pre_decml,
> > > +					&st->scale_post_decml);
> > > +
> > > +	/* Set Sensitivity field ids, when there is no individual
> > > modifier */
> > > +	if (hg_group->common_attributes.sensitivity.index < 0) {
> > > +		sensor_hub_input_get_attribute_info(
> > > +			hsdev, HID_FEATURE_REPORT, usage_id,
> > > +			HID_USAGE_SENSOR_DATA_MOD_CHANGE_SENSITIVITY_AB
> > > S |
> > > +				HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALU
> > > E_1,
> > > +			&hg_group->common_attributes.sensitivity);
> > > +		dev_dbg(&pdev->dev, "Sensitivity index:report %d:%d\n",
> > > +			hg_group->common_attributes.sensitivity.index,
> > > +			hg_group-
> > > > common_attributes.sensitivity.report_id);
> > > +	}
> > > +
> > > +	return ret;
> > > +}
> > > +
> > > +/* Function to initialize the processing for usage id */
> > > +static int hinge_add_iio_device(struct platform_device *pdev,
> > > int
> > > index,
> > > +				const char *name, struct hinge_state
> > > **st)
> > > +{
> > > +	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
> > > +	struct hinge_state *hg_state;
> > > +	struct iio_dev *indio_dev;
> > > +	int ret;
> > > +
> > > +	indio_dev =
> > > +		devm_iio_device_alloc(&pdev->dev, sizeof(struct
> > > hinge_state));
> > 
> > sizeof (*hg_state) preferred.
> > 
> > > +	if (indio_dev == NULL)
> > > +		return -ENOMEM;
> > > +
> > > +	hg_state = iio_priv(indio_dev);
> > > +	hg_state->indio_dev = indio_dev;
> > > +
> > > +	indio_dev->num_channels = ARRAY_SIZE(hinge_channels);
> > > +	indio_dev->channels =
> > > +		kmemdup(hinge_channels, sizeof(hinge_channels),
> > > GFP_KERNEL);
> > 
> > I don't immediately see anything that is modifying channels. As
> > such
> > you
> > should be able have it shared by all the instances.
> > 
> > > +	if (!indio_dev->channels)
> > > +		return -ENOMEM;
> > > +
> > > +	ret = hinge_parse_report(
> > > +		pdev, hsdev, hsdev->usage,
> > > +		HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_1 + index,
> > > hg_state);
> > > +	if (ret) {
> > > +		dev_err(&pdev->dev, "failed to setup attributes\n");
> > > +		goto error_free_dev_mem;
> > > +	}
> > > +
> > > +	indio_dev->dev.parent = &pdev->dev;
> > > +	indio_dev->info = &hinge_info;
> > > +	indio_dev->name = name;
> > > +	indio_dev->modes = INDIO_DIRECT_MODE;
> > > +
> > > +	ret = hid_sensor_setup_trigger(indio_dev, name,
> > > +				       &hg_group->common_attributes);
> > > +	if (ret < 0) {
> > > +		dev_err(&pdev->dev, "trigger setup failed\n");
> > > +		goto error_free_dev_mem;
> > > +	}
> > > +
> > > +	ret = iio_device_register(indio_dev);
> > > +	if (ret) {
> > > +		dev_err(&pdev->dev, "device register failed\n");
> > > +		goto error_remove_trigger;
> > > +	}
> > > +
> > > +	*st = hg_state;
> > > +
> > > +	return ret;
> > > +
> > > +error_remove_trigger:
> > > +	hid_sensor_remove_trigger(indio_dev, &hg_group-
> > > > common_attributes);
> > > +error_free_dev_mem:
> > > +	kfree(indio_dev->channels);
> > > +	return ret;
> > > +}
> > > +
> > > +/* Function to deinitialize the processing for usage id */
> > > +static int hinge_remove_iio_device(struct platform_device *pdev,
> > > int index)
> > > +{
> > > +	struct hinge_state *hg_state = hg_group->hg_states[index];
> > > +	struct iio_dev *indio_dev = hg_state->indio_dev;
> > > +
> > > +	iio_device_unregister(indio_dev);
> > > +	hid_sensor_remove_trigger(indio_dev, &hg_group-
> > > > common_attributes);
> > > +	kfree(indio_dev->channels);
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +static int hid_hinge_probe(struct platform_device *pdev)
> > > +{
> > > +	struct hinge_state *hg_state;
> > > +	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
> > > +	static const char *const names[] = { "hinge", "screen",
> > > "keyboard" };
> > > +	int ret;
> > > +	int i;
> > > +
> > > +	hg_group = devm_kzalloc(&pdev->dev, sizeof(struct hinge_group),
> > > +				GFP_KERNEL);
> > 
> > As mentioned above, I'd really not expect to see a global like
> > this.
> > Technically nothing stops there being more than one instance of
> > this
> > device on a platform (even if that would be a bit odd) + it's
> > almost
> > always cleaner to not use a global in the first place.
> > 
> > > +	if (!hg_group)
> > > +		return -ENOMEM;
> > > +
> > > +	hg_group->common_attributes.hsdev = hsdev;
> > > +	hg_group->common_attributes.pdev = pdev;
> > > +
> > > +	ret = hid_sensor_parse_common_attributes(hsdev, hsdev->usage,
> > > +						 &hg_group-
> > > > common_attributes);
> > > +	if (ret) {
> > > +		dev_err(&pdev->dev, "failed to setup common
> > > attributes\n");
> > > +		return ret;
> > > +	}
> > > +
> > > +	atomic_set(&hg_group->common_attributes.data_ready, 0);
> > > +	for (i = 0; i < IIO_DEV_NUM; i++) {
> > > +		ret = hinge_add_iio_device(pdev, i, names[i],
> > > &hg_state);
> > > +		if (ret)
> > > +			goto err_probe;
> > > +
> > > +		hg_group->hg_states[i] = hg_state;
> > > +	}
> > > +
> > > +	/* use the first iio device to do the PM */
> > > +	platform_set_drvdata(pdev, hg_group->hg_states[0]->indio_dev);
> > > +
> > > +	hg_group->callbacks.send_event = hinge_proc_event;
> > > +	hg_group->callbacks.capture_sample = hinge_capture_sample;
> > > +	hg_group->callbacks.pdev = pdev;
> > > +	ret = sensor_hub_register_callback(hsdev, hsdev->usage,
> > > +					   &hg_group->callbacks);
> > > +	if (ret < 0)
> > > +		dev_err(&pdev->dev, "callback reg failed\n");
> > > +
> > > +	return ret;
> > > +
> > > +err_probe:
> > > +	for (i--; i >= 0; i--)
> > > +		hinge_remove_iio_device(pdev, i);
> > > +
> > > +	return ret;
> > > +}
> > > +
> > > +/* Function to deinitialize the processing for usage id */
> > > +static int hid_hinge_remove(struct platform_device *pdev)
> > > +{
> > > +	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
> > > +	int i;
> > > +
> > > +	sensor_hub_remove_callback(hsdev, hsdev->usage);
> > > +
> > > +	for (i = 0; i < IIO_DEV_NUM; i++)
> > > +		hinge_remove_iio_device(pdev, i);
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +static const struct platform_device_id hid_hinge_ids[] = {
> > > +	{
> > > +		/* Format: HID-SENSOR-INT-usage_id_in_hex_lowercase */
> > > +		.name = "HID-SENSOR-INT-020b",
> > > +	},
> > > +	{ /* sentinel */ }
> > > +};
> > > +MODULE_DEVICE_TABLE(platform, hid_hinge_ids);
> > > +
> > > +static struct platform_driver hid_hinge_platform_driver = {
> > > +	.id_table = hid_hinge_ids,
> > > +	.driver = {
> > > +		.name	= KBUILD_MODNAME,
> > > +		.pm	= &hid_sensor_pm_ops,
> > > +	},
> > > +	.probe		= hid_hinge_probe,
> > > +	.remove		= hid_hinge_remove,
> > > +};
> > > +module_platform_driver(hid_hinge_platform_driver);
> > > +
> > > +MODULE_DESCRIPTION("HID Sensor Custom Hinge");
> > > +MODULE_AUTHOR("Ye Xiang <xiang.ye@intel.com>");
> > > +MODULE_LICENSE("GPL");

Jonathan Cameron Nov. 22, 2020, 2:14 p.m. UTC | #4

On Sun, 22 Nov 2020 02:14:16 +0000
"Pandruvada, Srinivas" <srinivas.pandruvada@intel.com> wrote:

> On Sat, 2020-11-21 at 17:46 -0800, Srinivas Pandruvada wrote:
> > On Sat, 2020-11-21 at 17:56 +0000, Jonathan Cameron wrote:  
> > > On Thu, 19 Nov 2020 18:03:31 +0800
> > > Ye Xiang <xiang.ye@intel.com> wrote:
> > >   
> > > > The Hinge sensor is a common custom sensor on laptops. It
> > > > calculates
> > > > the angle between the lid (screen) and the base (keyboard). In
> > > > addition,
> > > > it also exposes screen and the keyboard angels with respect to
> > > > the
> > > > ground. Applications can easily get laptop's status in space
> > > > through
> > > > this sensor, in order to display appropriate user interface.  
> > > 
> > > I'm a little unclear on why the 3 axes aren't treated as a single
> > > sensor.
> > > You seem to always grab the 3 together or am I missing something?
> > > 
> > > That will greatly simplify things and get rid of the need to have
> > > a shared trigger with the problems that causes in the previous
> > > patch.  
> > 
> > They are not three axes, they are independent. Xiang did try adding
> > x,
> > y and z component to represent x as hinge, y as keyboard and z as
> > lid.
> > But I was not convinced.
> > The problem is that then what will be sysfs interface? They are
> > really
> > a three sensors. Or we create new interface to call
> > in_angl_raw_keyboard
> > in_angl_raw_screen
> > in_angl_raw_lid.
> >   
> You seem to indicate this is possible now some new "label" patch.
> Is this the patch?
> commit 2c3d0c9ffd24d9b4c62c5dfb2104695a614be28c
> Author: Phil Reid <preid@electromag.com.au>
> Date:   Thu Sep 19 22:36:08 2019 +0800

Nope, this one 
https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio.git/commit/?id=1d4ef9b39ebecca827642b8897d2d79ea2026682

The one above adds a per device label which wouldn't be much use for your
case, but this one adds a per channel label.

Done via a read_label callback.

Here you'd want to use indexed channels so something like.

in_angl0_raw
in_angl1_raw
in_angl2_raw

and

in_angl0_label = keyboard
in_angl1_label = screen
in_angl2_label = lid



> 
> Ideally, one iio device here is much easy to manage as other HID
> sensors. If we can add something other that "x", "y" and "z" component.

Agreed, using axes makes no real sense here and extended_name is
just a mess from ABI point of view.  Trying to solve this was the
reason we added the _label interface.

Jonathan


> 
> Thanks,
> Srinivas
> 
> > Thanks,
> > Srinivas
> > 
> >   
> > > Thanks,
> > > 
> > > Jonathan
> > >   
> > > > Signed-off-by: Ye Xiang <xiang.ye@intel.com>
> > > > ---
> > > >  .../hid-sensors/hid-sensor-attributes.c       |   2 +
> > > >  drivers/iio/position/Kconfig                  |  16 +
> > > >  drivers/iio/position/Makefile                 |   3 +
> > > >  .../iio/position/hid-sensor-custom-hinge.c    | 412
> > > > ++++++++++++++++++  
> > > 
> > > Given it's custom probably needs a more specific name.  I guess
> > > hid-sensor-custom-intel-hinge.c might be safe?
> > > 
> > > Same for other places we need names in here.
> > >   
> > > >  4 files changed, 433 insertions(+)
> > > >  create mode 100644 drivers/iio/position/hid-sensor-custom-
> > > > hinge.c
> > > > 
> > > > diff --git a/drivers/iio/common/hid-sensors/hid-sensor-
> > > > attributes.c 
> > > > b/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> > > > index 442ff787f7af..5b822a4298a0 100644
> > > > --- a/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> > > > +++ b/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> > > > @@ -71,6 +71,8 @@ static struct {
> > > >  	{HID_USAGE_SENSOR_TEMPERATURE, HID_USAGE_SENSOR_UNITS_DEGREES,
> > > > 1000, 0},
> > > >  
> > > >  	{HID_USAGE_SENSOR_HUMIDITY, 0, 1000, 0},
> > > > +	{HID_USAGE_SENSOR_HINGE, 0, 0, 17453293},
> > > > +	{HID_USAGE_SENSOR_HINGE, HID_USAGE_SENSOR_UNITS_DEGREES, 0,
> > > > 17453293},
> > > >  };
> > > >  
> > > >  static void simple_div(int dividend, int divisor, int *whole,
> > > > diff --git a/drivers/iio/position/Kconfig
> > > > b/drivers/iio/position/Kconfig
> > > > index eda67f008c5b..0346f6f2b422 100644
> > > > --- a/drivers/iio/position/Kconfig
> > > > +++ b/drivers/iio/position/Kconfig
> > > > @@ -16,4 +16,20 @@ config IQS624_POS
> > > >  	  To compile this driver as a module, choose M here: the module
> > > >  	  will be called iqs624-pos.
> > > >  
> > > > +config HID_SENSOR_CUSTOM_HINGE
> > > > +	depends on HID_SENSOR_HUB
> > > > +	select IIO_BUFFER
> > > > +	select IIO_TRIGGERED_BUFFER
> > > > +	select HID_SENSOR_IIO_COMMON
> > > > +	select HID_SENSOR_IIO_TRIGGER
> > > > +	tristate "HID Hinge"
> > > > +	help
> > > > +	  This sensor present three angles, hinge angel, screen angles
> > > > +	  and keyboard angle respect to horizon (ground).
> > > > +	  Say yes here to build support for the HID SENSOR CUSTOM
> > > > +	  HINGE.  
> > > 
> > > Capitalization is a bit odd looking. I'd drop it.
> > >   
> > > > +
> > > > +	  To compile this driver as a module, choose M here: the
> > > > +	  module will be called hid-sensor-custom-hinge.
> > > > +
> > > >  endmenu
> > > > diff --git a/drivers/iio/position/Makefile
> > > > b/drivers/iio/position/Makefile
> > > > index 3cbe7a734352..7a6225977a01 100644
> > > > --- a/drivers/iio/position/Makefile
> > > > +++ b/drivers/iio/position/Makefile
> > > > @@ -5,3 +5,6 @@
> > > >  # When adding new entries keep the list in alphabetical order
> > > >  
> > > >  obj-$(CONFIG_IQS624_POS)	+= iqs624-pos.o
> > > > +
> > > > +obj-$(CONFIG_HID_SENSOR_CUSTOM_HINGE) += hid-sensor-custom-
> > > > hinge.o  
> > > 
> > > Alphabetical order preferred.
> > >   
> > > > +ccflags-y	+= -I$(srctree)/drivers/iio/common/hid-sensors  
> > > 
> > > Why?
> > >   
> > > > diff --git a/drivers/iio/position/hid-sensor-custom-hinge.c
> > > > b/drivers/iio/position/hid-sensor-custom-hinge.c
> > > > new file mode 100644
> > > > index 000000000000..a91b333f36fa
> > > > --- /dev/null
> > > > +++ b/drivers/iio/position/hid-sensor-custom-hinge.c
> > > > @@ -0,0 +1,412 @@
> > > > +// SPDX-License-Identifier: GPL-2.0-only
> > > > +/*
> > > > + * HID Sensors Driver
> > > > + * Copyright (c) 2020, Intel Corporation.
> > > > + */
> > > > +#include <linux/hid-sensor-hub.h>
> > > > +#include <linux/iio/buffer.h>
> > > > +#include <linux/iio/iio.h>
> > > > +#include <linux/platform_device.h>
> > > > +
> > > > +#include "hid-sensor-trigger.h"
> > > > +
> > > > +/* Channel definitions */
> > > > +static const struct iio_chan_spec hinge_channels[] = {
> > > > +	{ .type = IIO_ANGL,
> > > > +	  .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> > > > +	  .info_mask_shared_by_type =
> > > > +		  BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_SCALE)
> > > > +		  BIT(IIO_CHAN_INFO_SAMP_FREQ) |
> > > > BIT(IIO_CHAN_INFO_HYSTERESIS),
> > > > +	  .scan_type.realbits = 16,
> > > > +	  .scan_type.storagebits = 32,  
> > > 
> > > It a bit odd to see a single channel that is 16 bits inside a 32
> > > bit
> > > with
> > > no shift or similar.  Why not just pack it into 16 bits?
> > >   
> > > > +	  .scan_type.sign = 's',
> > > > +	  .scan_index = 0 },
> > > > +
> > > > +	IIO_CHAN_SOFT_TIMESTAMP(1)
> > > > +};
> > > > +
> > > > +struct hinge_state {
> > > > +	struct iio_dev *indio_dev;
> > > > +	struct hid_sensor_hub_attribute_info hinge;
> > > > +	/* Reserve for 1 channel + pading + timestamp */
> > > > +	u32 hinge_val[1 + 3];  
> > > 
> > > __aligned(8)
> > > 
> > > see below for requirements on this.
> > > Perhaps better to use
> > > 
> > > 	struct hinge_scan {
> > > 		u32 val;
> > > 		s64 timestamp __aligned(8); // Note this is needed for
> > > x86_32
> > > 	} scan;
> > >   
> > > > +	int scale_pre_decml;
> > > > +	int scale_post_decml;
> > > > +	int scale_precision;
> > > > +	int value_offset;
> > > > +	int64_t timestamp;
> > > > +	u32 hinge_address;
> > > > +};
> > > > +
> > > > +#define IIO_DEV_NUM 3  
> > > 
> > > That needs a prefix to make it clear it's not a generic constant
> > > but is specific to this driver.
> > >   
> > > > +
> > > > +struct hinge_group {
> > > > +	struct hinge_state *hg_states[IIO_DEV_NUM];
> > > > +	struct hid_sensor_hub_callbacks callbacks;
> > > > +	struct hid_sensor_common common_attributes;
> > > > +};
> > > > +
> > > > +static struct hinge_group *hg_group;  
> > > 
> > > We shouldn't see globals like this. Please figure out how to avoid
> > > it.
> > >   
> > > > +
> > > > +/* Channel read_raw handler */
> > > > +static int hinge_read_raw(struct iio_dev *indio_dev,
> > > > +			  struct iio_chan_spec const *chan, int *val,
> > > > int *val2,
> > > > +			  long mask)
> > > > +{
> > > > +	struct hinge_state *hg_state = iio_priv(indio_dev);
> > > > +	struct hid_sensor_hub_device *hsdev;
> > > > +	int report_id = -1;
> > > > +	int ret_type;
> > > > +	s32 min;
> > > > +
> > > > +	hsdev = hg_group->common_attributes.hsdev;
> > > > +
> > > > +	*val = 0;
> > > > +	*val2 = 0;
> > > > +	switch (mask) {
> > > > +	case IIO_CHAN_INFO_RAW:
> > > > +		hid_sensor_power_state(&hg_group->common_attributes,
> > > > true);
> > > > +		report_id = hg_state->hinge.report_id;
> > > > +		min = hg_state->hinge.logical_minimum;
> > > > +		if (report_id < 0) {
> > > > +			*val = 0;
> > > > +			hid_sensor_power_state(&hg_group-  
> > > > > common_attributes,  
> > > > +					       false);
> > > > +			return -EINVAL;
> > > > +		}
> > > > +
> > > > +		*val = sensor_hub_input_attr_get_raw_value(
> > > > +			hg_group->common_attributes.hsdev, hsdev-  
> > > > > usage,  
> > > > +			hg_state->hinge_address, report_id,
> > > > SENSOR_HUB_SYNC,
> > > > +			min < 0);
> > > > +
> > > > +		hid_sensor_power_state(&hg_group->common_attributes,
> > > > false);
> > > > +		ret_type = IIO_VAL_INT;
> > > > +		break;
> > > > +	case IIO_CHAN_INFO_SCALE:
> > > > +		*val = hg_state->scale_pre_decml;
> > > > +		*val2 = hg_state->scale_post_decml;
> > > > +		ret_type = hg_state->scale_precision;
> > > > +		break;
> > > > +	case IIO_CHAN_INFO_OFFSET:
> > > > +		*val = hg_state->value_offset;
> > > > +		ret_type = IIO_VAL_INT;
> > > > +		break;
> > > > +	case IIO_CHAN_INFO_SAMP_FREQ:
> > > > +		ret_type = hid_sensor_read_samp_freq_value(
> > > > +			&hg_group->common_attributes, val, val2);
> > > > +		break;
> > > > +	case IIO_CHAN_INFO_HYSTERESIS:
> > > > +		ret_type = hid_sensor_read_raw_hyst_value(
> > > > +			&hg_group->common_attributes, val, val2);
> > > > +		break;
> > > > +	default:
> > > > +		ret_type = -EINVAL;
> > > > +		break;
> > > > +	}
> > > > +
> > > > +	return ret_type;
> > > > +}
> > > > +
> > > > +/* Channel write_raw handler */
> > > > +static int hinge_write_raw(struct iio_dev *indio_dev,
> > > > +			   struct iio_chan_spec const *chan, int val,
> > > > int val2,
> > > > +			   long mask)
> > > > +{
> > > > +	int ret;
> > > > +
> > > > +	switch (mask) {
> > > > +	case IIO_CHAN_INFO_SAMP_FREQ:
> > > > +		ret = hid_sensor_write_samp_freq_value(
> > > > +			&hg_group->common_attributes, val, val2);
> > > > +		break;
> > > > +	case IIO_CHAN_INFO_HYSTERESIS:
> > > > +		ret = hid_sensor_write_raw_hyst_value(
> > > > +			&hg_group->common_attributes, val, val2);
> > > > +
> > > > +		break;
> > > > +	default:
> > > > +		ret = -EINVAL;
> > > > +	}
> > > > +
> > > > +	return ret;
> > > > +}
> > > > +
> > > > +static const struct iio_info hinge_info = {
> > > > +	.read_raw = &hinge_read_raw,
> > > > +	.write_raw = &hinge_write_raw,
> > > > +};
> > > > +
> > > > +/*
> > > > + * Function to push data to buffer;
> > > > + * wrapper added for symmetry with other hid-sensor drivers
> > > > + */
> > > > +static void hid_sensor_push_data(struct iio_dev *indio_dev, void
> > > > *data, int len,  
> > > 
> > > This doesn't seem to be generic, so don't name it as such.
> > >   
> > > > +				 int64_t timestamp)
> > > > +{
> > > > +	iio_push_to_buffers_with_timestamp(indio_dev, data, timestamp);  
> > > I hope that data buffer obeys the various rules needed by (and
> > > admittedly
> > > not that well documented) iio_push_to_buffers_with_timestamp()
> > > 
> > > 1. Needs to be 8 byte aligned.
> > > 2. Needs to have space for an aligned 8 byte timestamp at the end.
> > >   
> > > > +}
> > > > +
> > > > +/*
> > > > + * Callback handler to send event after all samples are received
> > > > + * and captured.
> > > > + */
> > > > +static int hinge_proc_event(struct hid_sensor_hub_device *hsdev,
> > > > +			    unsigned int usage_id, void *priv)
> > > > +{
> > > > +	int i;
> > > > +
> > > > +	for (i = 0; i < IIO_DEV_NUM; ++i) {  
> > > If we push for all sensors together, better to have
> > > this as a single iio_device with 3 channels.
> > > 
> > > Use the channel labels (just added to IIO) to identify which is
> > > which.
> > >   
> > > > +		struct hinge_state *hg_state;
> > > > +		struct iio_dev *indio_dev;
> > > > +
> > > > +		hg_state = hg_group->hg_states[i];
> > > > +		indio_dev = hg_state->indio_dev;
> > > > +
> > > > +		dev_dbg(&indio_dev->dev, "%s timestamp:%llu
> > > > scan_bytes:%d\n",
> > > > +			__func__, hg_state->timestamp, indio_dev-  
> > > > > scan_bytes);  
> > > > +
> > > > +		if (!hg_state->timestamp)
> > > > +			hg_state->timestamp =
> > > > iio_get_time_ns(indio_dev);
> > > > +
> > > > +		hid_sensor_push_data(indio_dev, hg_state->hinge_val,
> > > > +				     sizeof(hg_state->hinge_val),
> > > > +				     hg_state->timestamp);
> > > > +
> > > > +		hg_state->timestamp = 0;
> > > > +	}
> > > > +
> > > > +	return 0;
> > > > +}
> > > > +
> > > > +/* Capture samples in local storage */
> > > > +static int hinge_capture_sample(struct hid_sensor_hub_device
> > > > *hsdev,
> > > > +				unsigned int usage_id, size_t raw_len,
> > > > +				char *raw_data, void *priv)
> > > > +{
> > > > +	struct hinge_state *hg_state;
> > > > +	int offset;
> > > > +	int ret = -EINVAL;
> > > > +	int i;
> > > > +
> > > > +	if (usage_id == HID_USAGE_SENSOR_TIME_TIMESTAMP) {
> > > > +		for (i = 0; i < IIO_DEV_NUM; i++)
> > > > +			hg_group->hg_states[i]->timestamp =  
> > > 
> > > This rather implies all the data is captured together... If so
> > > single
> > > iio_device may make more sense.
> > >   
> > > > +				hid_sensor_convert_timestamp(
> > > > +					&hg_group->common_attributes,
> > > > +					*(int64_t *)raw_data);
> > > > +		return 0;
> > > > +	}
> > > > +
> > > > +	switch (usage_id) {
> > > > +	case HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_1:
> > > > +	case HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_2:
> > > > +	case HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_3:
> > > > +		offset = usage_id -
> > > > HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_1;
> > > > +		hg_state = hg_group->hg_states[offset];
> > > > +		hg_state->hinge_val[0] = *(u32 *)raw_data;
> > > > +		ret = 0;  
> > > 
> > > 		return 0;
> > >   
> > > > +		break;
> > > > +	default:  
> > > 		return -EINVAL;  
> > > > +		break;
> > > > +	}
> > > > +
> > > > +	return ret;
> > > > +}
> > > > +
> > > > +/* Parse report which is specific to an usage id */
> > > > +static int hinge_parse_report(struct platform_device *pdev,
> > > > +			      struct hid_sensor_hub_device *hsdev,
> > > > +			      unsigned int usage_id, unsigned int
> > > > attr_usage_id,
> > > > +			      struct hinge_state *st)
> > > > +{
> > > > +	int ret;
> > > > +
> > > > +	ret = sensor_hub_input_get_attribute_info(
> > > > +		hsdev, HID_INPUT_REPORT, usage_id, attr_usage_id, &st-  
> > > > > hinge);  
> > > > +	if (ret < 0)
> > > > +		return ret;
> > > > +
> > > > +	st->hinge_address = attr_usage_id;
> > > > +	st->scale_precision =
> > > > +		hid_sensor_format_scale(HID_USAGE_SENSOR_HINGE, &st-  
> > > > > hinge,  
> > > > +					&st->scale_pre_decml,
> > > > +					&st->scale_post_decml);
> > > > +
> > > > +	/* Set Sensitivity field ids, when there is no individual
> > > > modifier */
> > > > +	if (hg_group->common_attributes.sensitivity.index < 0) {
> > > > +		sensor_hub_input_get_attribute_info(
> > > > +			hsdev, HID_FEATURE_REPORT, usage_id,
> > > > +			HID_USAGE_SENSOR_DATA_MOD_CHANGE_SENSITIVITY_AB
> > > > S |
> > > > +				HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALU
> > > > E_1,
> > > > +			&hg_group->common_attributes.sensitivity);
> > > > +		dev_dbg(&pdev->dev, "Sensitivity index:report %d:%d\n",
> > > > +			hg_group->common_attributes.sensitivity.index,
> > > > +			hg_group-  
> > > > > common_attributes.sensitivity.report_id);  
> > > > +	}
> > > > +
> > > > +	return ret;
> > > > +}
> > > > +
> > > > +/* Function to initialize the processing for usage id */
> > > > +static int hinge_add_iio_device(struct platform_device *pdev,
> > > > int
> > > > index,
> > > > +				const char *name, struct hinge_state
> > > > **st)
> > > > +{
> > > > +	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
> > > > +	struct hinge_state *hg_state;
> > > > +	struct iio_dev *indio_dev;
> > > > +	int ret;
> > > > +
> > > > +	indio_dev =
> > > > +		devm_iio_device_alloc(&pdev->dev, sizeof(struct
> > > > hinge_state));  
> > > 
> > > sizeof (*hg_state) preferred.
> > >   
> > > > +	if (indio_dev == NULL)
> > > > +		return -ENOMEM;
> > > > +
> > > > +	hg_state = iio_priv(indio_dev);
> > > > +	hg_state->indio_dev = indio_dev;
> > > > +
> > > > +	indio_dev->num_channels = ARRAY_SIZE(hinge_channels);
> > > > +	indio_dev->channels =
> > > > +		kmemdup(hinge_channels, sizeof(hinge_channels),
> > > > GFP_KERNEL);  
> > > 
> > > I don't immediately see anything that is modifying channels. As
> > > such
> > > you
> > > should be able have it shared by all the instances.
> > >   
> > > > +	if (!indio_dev->channels)
> > > > +		return -ENOMEM;
> > > > +
> > > > +	ret = hinge_parse_report(
> > > > +		pdev, hsdev, hsdev->usage,
> > > > +		HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_1 + index,
> > > > hg_state);
> > > > +	if (ret) {
> > > > +		dev_err(&pdev->dev, "failed to setup attributes\n");
> > > > +		goto error_free_dev_mem;
> > > > +	}
> > > > +
> > > > +	indio_dev->dev.parent = &pdev->dev;
> > > > +	indio_dev->info = &hinge_info;
> > > > +	indio_dev->name = name;
> > > > +	indio_dev->modes = INDIO_DIRECT_MODE;
> > > > +
> > > > +	ret = hid_sensor_setup_trigger(indio_dev, name,
> > > > +				       &hg_group->common_attributes);
> > > > +	if (ret < 0) {
> > > > +		dev_err(&pdev->dev, "trigger setup failed\n");
> > > > +		goto error_free_dev_mem;
> > > > +	}
> > > > +
> > > > +	ret = iio_device_register(indio_dev);
> > > > +	if (ret) {
> > > > +		dev_err(&pdev->dev, "device register failed\n");
> > > > +		goto error_remove_trigger;
> > > > +	}
> > > > +
> > > > +	*st = hg_state;
> > > > +
> > > > +	return ret;
> > > > +
> > > > +error_remove_trigger:
> > > > +	hid_sensor_remove_trigger(indio_dev, &hg_group-  
> > > > > common_attributes);  
> > > > +error_free_dev_mem:
> > > > +	kfree(indio_dev->channels);
> > > > +	return ret;
> > > > +}
> > > > +
> > > > +/* Function to deinitialize the processing for usage id */
> > > > +static int hinge_remove_iio_device(struct platform_device *pdev,
> > > > int index)
> > > > +{
> > > > +	struct hinge_state *hg_state = hg_group->hg_states[index];
> > > > +	struct iio_dev *indio_dev = hg_state->indio_dev;
> > > > +
> > > > +	iio_device_unregister(indio_dev);
> > > > +	hid_sensor_remove_trigger(indio_dev, &hg_group-  
> > > > > common_attributes);  
> > > > +	kfree(indio_dev->channels);
> > > > +
> > > > +	return 0;
> > > > +}
> > > > +
> > > > +static int hid_hinge_probe(struct platform_device *pdev)
> > > > +{
> > > > +	struct hinge_state *hg_state;
> > > > +	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
> > > > +	static const char *const names[] = { "hinge", "screen",
> > > > "keyboard" };
> > > > +	int ret;
> > > > +	int i;
> > > > +
> > > > +	hg_group = devm_kzalloc(&pdev->dev, sizeof(struct hinge_group),
> > > > +				GFP_KERNEL);  
> > > 
> > > As mentioned above, I'd really not expect to see a global like
> > > this.
> > > Technically nothing stops there being more than one instance of
> > > this
> > > device on a platform (even if that would be a bit odd) + it's
> > > almost
> > > always cleaner to not use a global in the first place.
> > >   
> > > > +	if (!hg_group)
> > > > +		return -ENOMEM;
> > > > +
> > > > +	hg_group->common_attributes.hsdev = hsdev;
> > > > +	hg_group->common_attributes.pdev = pdev;
> > > > +
> > > > +	ret = hid_sensor_parse_common_attributes(hsdev, hsdev->usage,
> > > > +						 &hg_group-  
> > > > > common_attributes);  
> > > > +	if (ret) {
> > > > +		dev_err(&pdev->dev, "failed to setup common
> > > > attributes\n");
> > > > +		return ret;
> > > > +	}
> > > > +
> > > > +	atomic_set(&hg_group->common_attributes.data_ready, 0);
> > > > +	for (i = 0; i < IIO_DEV_NUM; i++) {
> > > > +		ret = hinge_add_iio_device(pdev, i, names[i],
> > > > &hg_state);
> > > > +		if (ret)
> > > > +			goto err_probe;
> > > > +
> > > > +		hg_group->hg_states[i] = hg_state;
> > > > +	}
> > > > +
> > > > +	/* use the first iio device to do the PM */
> > > > +	platform_set_drvdata(pdev, hg_group->hg_states[0]->indio_dev);
> > > > +
> > > > +	hg_group->callbacks.send_event = hinge_proc_event;
> > > > +	hg_group->callbacks.capture_sample = hinge_capture_sample;
> > > > +	hg_group->callbacks.pdev = pdev;
> > > > +	ret = sensor_hub_register_callback(hsdev, hsdev->usage,
> > > > +					   &hg_group->callbacks);
> > > > +	if (ret < 0)
> > > > +		dev_err(&pdev->dev, "callback reg failed\n");
> > > > +
> > > > +	return ret;
> > > > +
> > > > +err_probe:
> > > > +	for (i--; i >= 0; i--)
> > > > +		hinge_remove_iio_device(pdev, i);
> > > > +
> > > > +	return ret;
> > > > +}
> > > > +
> > > > +/* Function to deinitialize the processing for usage id */
> > > > +static int hid_hinge_remove(struct platform_device *pdev)
> > > > +{
> > > > +	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
> > > > +	int i;
> > > > +
> > > > +	sensor_hub_remove_callback(hsdev, hsdev->usage);
> > > > +
> > > > +	for (i = 0; i < IIO_DEV_NUM; i++)
> > > > +		hinge_remove_iio_device(pdev, i);
> > > > +
> > > > +	return 0;
> > > > +}
> > > > +
> > > > +static const struct platform_device_id hid_hinge_ids[] = {
> > > > +	{
> > > > +		/* Format: HID-SENSOR-INT-usage_id_in_hex_lowercase */
> > > > +		.name = "HID-SENSOR-INT-020b",
> > > > +	},
> > > > +	{ /* sentinel */ }
> > > > +};
> > > > +MODULE_DEVICE_TABLE(platform, hid_hinge_ids);
> > > > +
> > > > +static struct platform_driver hid_hinge_platform_driver = {
> > > > +	.id_table = hid_hinge_ids,
> > > > +	.driver = {
> > > > +		.name	= KBUILD_MODNAME,
> > > > +		.pm	= &hid_sensor_pm_ops,
> > > > +	},
> > > > +	.probe		= hid_hinge_probe,
> > > > +	.remove		= hid_hinge_remove,
> > > > +};
> > > > +module_platform_driver(hid_hinge_platform_driver);
> > > > +
> > > > +MODULE_DESCRIPTION("HID Sensor Custom Hinge");
> > > > +MODULE_AUTHOR("Ye Xiang <xiang.ye@intel.com>");
> > > > +MODULE_LICENSE("GPL");

Pandruvada, Srinivas Nov. 22, 2020, 3:51 p.m. UTC | #5

On Sun, 2020-11-22 at 14:14 +0000, Jonathan Cameron wrote:
> On Sun, 22 Nov 2020 02:14:16 +0000
> "Pandruvada, Srinivas" <srinivas.pandruvada@intel.com> wrote:
> 
> > On Sat, 2020-11-21 at 17:46 -0800, Srinivas Pandruvada wrote:
> > > On Sat, 2020-11-21 at 17:56 +0000, Jonathan Cameron wrote:  
> > > > On Thu, 19 Nov 2020 18:03:31 +0800
> > > > Ye Xiang <xiang.ye@intel.com> wrote:
> > > >   
> > > > > The Hinge sensor is a common custom sensor on laptops. It
> > > > > calculates
> > > > > the angle between the lid (screen) and the base (keyboard).
> > > > > In
> > > > > addition,
> > > > > it also exposes screen and the keyboard angels with respect
> > > > > to
> > > > > the
> > > > > ground. Applications can easily get laptop's status in space
> > > > > through
> > > > > this sensor, in order to display appropriate user
> > > > > interface.  
> > > > 
> > > > I'm a little unclear on why the 3 axes aren't treated as a
> > > > single
> > > > sensor.
> > > > You seem to always grab the 3 together or am I missing
> > > > something?
> > > > 
> > > > That will greatly simplify things and get rid of the need to
> > > > have
> > > > a shared trigger with the problems that causes in the previous
> > > > patch.  
> > > 
> > > They are not three axes, they are independent. Xiang did try
> > > adding
> > > x,
> > > y and z component to represent x as hinge, y as keyboard and z as
> > > lid.
> > > But I was not convinced.
> > > The problem is that then what will be sysfs interface? They are
> > > really
> > > a three sensors. Or we create new interface to call
> > > in_angl_raw_keyboard
> > > in_angl_raw_screen
> > > in_angl_raw_lid.
> > >   
> > You seem to indicate this is possible now some new "label" patch.
> > Is this the patch?
> > commit 2c3d0c9ffd24d9b4c62c5dfb2104695a614be28c
> > Author: Phil Reid <preid@electromag.com.au>
> > Date:   Thu Sep 19 22:36:08 2019 +0800
> 
> Nope, this one 
> https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio.git/commit/?id=1d4ef9b39ebecca827642b8897d2d79ea2026682
> 
> The one above adds a per device label which wouldn't be much use for
> your
> case, but this one adds a per channel label.
> 
> Done via a read_label callback.
> 
> Here you'd want to use indexed channels so something like.
> 
> in_angl0_raw
> in_angl1_raw
> in_angl2_raw
> 
> and
> 
> in_angl0_label = keyboard
> in_angl1_label = screen
> in_angl2_label = lid

Thanks Jonathan. This will make the job easier.
Xiang,
You can use this method. Then you will not need other changes except
patch 1/4.
Also add a documentation patch to explain the mapping.

Thanks,
Srinivas

> 
> 
> 
> > Ideally, one iio device here is much easy to manage as other HID
> > sensors. If we can add something other that "x", "y" and "z"
> > component.
> 
> Agreed, using axes makes no real sense here and extended_name is
> just a mess from ABI point of view.  Trying to solve this was the
> reason we added the _label interface.
> 
> Jonathan
> 
> 
> > Thanks,
> > Srinivas
> > 
> > > Thanks,
> > > Srinivas
> > > 
> > >   
> > > > Thanks,
> > > > 
> > > > Jonathan
> > > >   
> > > > > Signed-off-by: Ye Xiang <xiang.ye@intel.com>
> > > > > ---
> > > > >  .../hid-sensors/hid-sensor-attributes.c       |   2 +
> > > > >  drivers/iio/position/Kconfig                  |  16 +
> > > > >  drivers/iio/position/Makefile                 |   3 +
> > > > >  .../iio/position/hid-sensor-custom-hinge.c    | 412
> > > > > ++++++++++++++++++  
> > > > 
> > > > Given it's custom probably needs a more specific name.  I guess
> > > > hid-sensor-custom-intel-hinge.c might be safe?
> > > > 
> > > > Same for other places we need names in here.
> > > >   
> > > > >  4 files changed, 433 insertions(+)
> > > > >  create mode 100644 drivers/iio/position/hid-sensor-custom-
> > > > > hinge.c
> > > > > 
> > > > > diff --git a/drivers/iio/common/hid-sensors/hid-sensor-
> > > > > attributes.c 
> > > > > b/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> > > > > index 442ff787f7af..5b822a4298a0 100644
> > > > > --- a/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> > > > > +++ b/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> > > > > @@ -71,6 +71,8 @@ static struct {
> > > > >  	{HID_USAGE_SENSOR_TEMPERATURE,
> > > > > HID_USAGE_SENSOR_UNITS_DEGREES,
> > > > > 1000, 0},
> > > > >  
> > > > >  	{HID_USAGE_SENSOR_HUMIDITY, 0, 1000, 0},
> > > > > +	{HID_USAGE_SENSOR_HINGE, 0, 0, 17453293},
> > > > > +	{HID_USAGE_SENSOR_HINGE,
> > > > > HID_USAGE_SENSOR_UNITS_DEGREES, 0,
> > > > > 17453293},
> > > > >  };
> > > > >  
> > > > >  static void simple_div(int dividend, int divisor, int
> > > > > *whole,
> > > > > diff --git a/drivers/iio/position/Kconfig
> > > > > b/drivers/iio/position/Kconfig
> > > > > index eda67f008c5b..0346f6f2b422 100644
> > > > > --- a/drivers/iio/position/Kconfig
> > > > > +++ b/drivers/iio/position/Kconfig
> > > > > @@ -16,4 +16,20 @@ config IQS624_POS
> > > > >  	  To compile this driver as a module, choose M here:
> > > > > the module
> > > > >  	  will be called iqs624-pos.
> > > > >  
> > > > > +config HID_SENSOR_CUSTOM_HINGE
> > > > > +	depends on HID_SENSOR_HUB
> > > > > +	select IIO_BUFFER
> > > > > +	select IIO_TRIGGERED_BUFFER
> > > > > +	select HID_SENSOR_IIO_COMMON
> > > > > +	select HID_SENSOR_IIO_TRIGGER
> > > > > +	tristate "HID Hinge"
> > > > > +	help
> > > > > +	  This sensor present three angles, hinge angel, screen
> > > > > angles
> > > > > +	  and keyboard angle respect to horizon (ground).
> > > > > +	  Say yes here to build support for the HID SENSOR
> > > > > CUSTOM
> > > > > +	  HINGE.  
> > > > 
> > > > Capitalization is a bit odd looking. I'd drop it.
> > > >   
> > > > > +
> > > > > +	  To compile this driver as a module, choose M here:
> > > > > the
> > > > > +	  module will be called hid-sensor-custom-hinge.
> > > > > +
> > > > >  endmenu
> > > > > diff --git a/drivers/iio/position/Makefile
> > > > > b/drivers/iio/position/Makefile
> > > > > index 3cbe7a734352..7a6225977a01 100644
> > > > > --- a/drivers/iio/position/Makefile
> > > > > +++ b/drivers/iio/position/Makefile
> > > > > @@ -5,3 +5,6 @@
> > > > >  # When adding new entries keep the list in alphabetical
> > > > > order
> > > > >  
> > > > >  obj-$(CONFIG_IQS624_POS)	+= iqs624-pos.o
> > > > > +
> > > > > +obj-$(CONFIG_HID_SENSOR_CUSTOM_HINGE) += hid-sensor-custom-
> > > > > hinge.o  
> > > > 
> > > > Alphabetical order preferred.
> > > >   
> > > > > +ccflags-y	+= -I$(srctree)/drivers/iio/common/hid-
> > > > > sensors  
> > > > 
> > > > Why?
> > > >   
> > > > > diff --git a/drivers/iio/position/hid-sensor-custom-hinge.c
> > > > > b/drivers/iio/position/hid-sensor-custom-hinge.c
> > > > > new file mode 100644
> > > > > index 000000000000..a91b333f36fa
> > > > > --- /dev/null
> > > > > +++ b/drivers/iio/position/hid-sensor-custom-hinge.c
> > > > > @@ -0,0 +1,412 @@
> > > > > +// SPDX-License-Identifier: GPL-2.0-only
> > > > > +/*
> > > > > + * HID Sensors Driver
> > > > > + * Copyright (c) 2020, Intel Corporation.
> > > > > + */
> > > > > +#include <linux/hid-sensor-hub.h>
> > > > > +#include <linux/iio/buffer.h>
> > > > > +#include <linux/iio/iio.h>
> > > > > +#include <linux/platform_device.h>
> > > > > +
> > > > > +#include "hid-sensor-trigger.h"
> > > > > +
> > > > > +/* Channel definitions */
> > > > > +static const struct iio_chan_spec hinge_channels[] = {
> > > > > +	{ .type = IIO_ANGL,
> > > > > +	  .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> > > > > +	  .info_mask_shared_by_type =
> > > > > +		  BIT(IIO_CHAN_INFO_OFFSET) |
> > > > > BIT(IIO_CHAN_INFO_SCALE)
> > > > > +		  BIT(IIO_CHAN_INFO_SAMP_FREQ) |
> > > > > BIT(IIO_CHAN_INFO_HYSTERESIS),
> > > > > +	  .scan_type.realbits = 16,
> > > > > +	  .scan_type.storagebits = 32,  
> > > > 
> > > > It a bit odd to see a single channel that is 16 bits inside a
> > > > 32
> > > > bit
> > > > with
> > > > no shift or similar.  Why not just pack it into 16 bits?
> > > >   
> > > > > +	  .scan_type.sign = 's',
> > > > > +	  .scan_index = 0 },
> > > > > +
> > > > > +	IIO_CHAN_SOFT_TIMESTAMP(1)
> > > > > +};
> > > > > +
> > > > > +struct hinge_state {
> > > > > +	struct iio_dev *indio_dev;
> > > > > +	struct hid_sensor_hub_attribute_info hinge;
> > > > > +	/* Reserve for 1 channel + pading + timestamp */
> > > > > +	u32 hinge_val[1 + 3];  
> > > > 
> > > > __aligned(8)
> > > > 
> > > > see below for requirements on this.
> > > > Perhaps better to use
> > > > 
> > > > 	struct hinge_scan {
> > > > 		u32 val;
> > > > 		s64 timestamp __aligned(8); // Note this is
> > > > needed for
> > > > x86_32
> > > > 	} scan;
> > > >   
> > > > > +	int scale_pre_decml;
> > > > > +	int scale_post_decml;
> > > > > +	int scale_precision;
> > > > > +	int value_offset;
> > > > > +	int64_t timestamp;
> > > > > +	u32 hinge_address;
> > > > > +};
> > > > > +
> > > > > +#define IIO_DEV_NUM 3  
> > > > 
> > > > That needs a prefix to make it clear it's not a generic
> > > > constant
> > > > but is specific to this driver.
> > > >   
> > > > > +
> > > > > +struct hinge_group {
> > > > > +	struct hinge_state *hg_states[IIO_DEV_NUM];
> > > > > +	struct hid_sensor_hub_callbacks callbacks;
> > > > > +	struct hid_sensor_common common_attributes;
> > > > > +};
> > > > > +
> > > > > +static struct hinge_group *hg_group;  
> > > > 
> > > > We shouldn't see globals like this. Please figure out how to
> > > > avoid
> > > > it.
> > > >   
> > > > > +
> > > > > +/* Channel read_raw handler */
> > > > > +static int hinge_read_raw(struct iio_dev *indio_dev,
> > > > > +			  struct iio_chan_spec const *chan, int
> > > > > *val,
> > > > > int *val2,
> > > > > +			  long mask)
> > > > > +{
> > > > > +	struct hinge_state *hg_state = iio_priv(indio_dev);
> > > > > +	struct hid_sensor_hub_device *hsdev;
> > > > > +	int report_id = -1;
> > > > > +	int ret_type;
> > > > > +	s32 min;
> > > > > +
> > > > > +	hsdev = hg_group->common_attributes.hsdev;
> > > > > +
> > > > > +	*val = 0;
> > > > > +	*val2 = 0;
> > > > > +	switch (mask) {
> > > > > +	case IIO_CHAN_INFO_RAW:
> > > > > +		hid_sensor_power_state(&hg_group-
> > > > > >common_attributes,
> > > > > true);
> > > > > +		report_id = hg_state->hinge.report_id;
> > > > > +		min = hg_state->hinge.logical_minimum;
> > > > > +		if (report_id < 0) {
> > > > > +			*val = 0;
> > > > > +			hid_sensor_power_state(&hg_group-  
> > > > > > common_attributes,  
> > > > > +					       false);
> > > > > +			return -EINVAL;
> > > > > +		}
> > > > > +
> > > > > +		*val = sensor_hub_input_attr_get_raw_value(
> > > > > +			hg_group->common_attributes.hsdev,
> > > > > hsdev-  
> > > > > > usage,  
> > > > > +			hg_state->hinge_address, report_id,
> > > > > SENSOR_HUB_SYNC,
> > > > > +			min < 0);
> > > > > +
> > > > > +		hid_sensor_power_state(&hg_group-
> > > > > >common_attributes,
> > > > > false);
> > > > > +		ret_type = IIO_VAL_INT;
> > > > > +		break;
> > > > > +	case IIO_CHAN_INFO_SCALE:
> > > > > +		*val = hg_state->scale_pre_decml;
> > > > > +		*val2 = hg_state->scale_post_decml;
> > > > > +		ret_type = hg_state->scale_precision;
> > > > > +		break;
> > > > > +	case IIO_CHAN_INFO_OFFSET:
> > > > > +		*val = hg_state->value_offset;
> > > > > +		ret_type = IIO_VAL_INT;
> > > > > +		break;
> > > > > +	case IIO_CHAN_INFO_SAMP_FREQ:
> > > > > +		ret_type = hid_sensor_read_samp_freq_value(
> > > > > +			&hg_group->common_attributes, val,
> > > > > val2);
> > > > > +		break;
> > > > > +	case IIO_CHAN_INFO_HYSTERESIS:
> > > > > +		ret_type = hid_sensor_read_raw_hyst_value(
> > > > > +			&hg_group->common_attributes, val,
> > > > > val2);
> > > > > +		break;
> > > > > +	default:
> > > > > +		ret_type = -EINVAL;
> > > > > +		break;
> > > > > +	}
> > > > > +
> > > > > +	return ret_type;
> > > > > +}
> > > > > +
> > > > > +/* Channel write_raw handler */
> > > > > +static int hinge_write_raw(struct iio_dev *indio_dev,
> > > > > +			   struct iio_chan_spec const *chan,
> > > > > int val,
> > > > > int val2,
> > > > > +			   long mask)
> > > > > +{
> > > > > +	int ret;
> > > > > +
> > > > > +	switch (mask) {
> > > > > +	case IIO_CHAN_INFO_SAMP_FREQ:
> > > > > +		ret = hid_sensor_write_samp_freq_value(
> > > > > +			&hg_group->common_attributes, val,
> > > > > val2);
> > > > > +		break;
> > > > > +	case IIO_CHAN_INFO_HYSTERESIS:
> > > > > +		ret = hid_sensor_write_raw_hyst_value(
> > > > > +			&hg_group->common_attributes, val,
> > > > > val2);
> > > > > +
> > > > > +		break;
> > > > > +	default:
> > > > > +		ret = -EINVAL;
> > > > > +	}
> > > > > +
> > > > > +	return ret;
> > > > > +}
> > > > > +
> > > > > +static const struct iio_info hinge_info = {
> > > > > +	.read_raw = &hinge_read_raw,
> > > > > +	.write_raw = &hinge_write_raw,
> > > > > +};
> > > > > +
> > > > > +/*
> > > > > + * Function to push data to buffer;
> > > > > + * wrapper added for symmetry with other hid-sensor drivers
> > > > > + */
> > > > > +static void hid_sensor_push_data(struct iio_dev *indio_dev,
> > > > > void
> > > > > *data, int len,  
> > > > 
> > > > This doesn't seem to be generic, so don't name it as such.
> > > >   
> > > > > +				 int64_t timestamp)
> > > > > +{
> > > > > +	iio_push_to_buffers_with_timestamp(indio_dev, data,
> > > > > timestamp);  
> > > > I hope that data buffer obeys the various rules needed by (and
> > > > admittedly
> > > > not that well documented) iio_push_to_buffers_with_timestamp()
> > > > 
> > > > 1. Needs to be 8 byte aligned.
> > > > 2. Needs to have space for an aligned 8 byte timestamp at the
> > > > end.
> > > >   
> > > > > +}
> > > > > +
> > > > > +/*
> > > > > + * Callback handler to send event after all samples are
> > > > > received
> > > > > + * and captured.
> > > > > + */
> > > > > +static int hinge_proc_event(struct hid_sensor_hub_device
> > > > > *hsdev,
> > > > > +			    unsigned int usage_id, void *priv)
> > > > > +{
> > > > > +	int i;
> > > > > +
> > > > > +	for (i = 0; i < IIO_DEV_NUM; ++i) {  
> > > > If we push for all sensors together, better to have
> > > > this as a single iio_device with 3 channels.
> > > > 
> > > > Use the channel labels (just added to IIO) to identify which is
> > > > which.
> > > >   
> > > > > +		struct hinge_state *hg_state;
> > > > > +		struct iio_dev *indio_dev;
> > > > > +
> > > > > +		hg_state = hg_group->hg_states[i];
> > > > > +		indio_dev = hg_state->indio_dev;
> > > > > +
> > > > > +		dev_dbg(&indio_dev->dev, "%s timestamp:%llu
> > > > > scan_bytes:%d\n",
> > > > > +			__func__, hg_state->timestamp,
> > > > > indio_dev-  
> > > > > > scan_bytes);  
> > > > > +
> > > > > +		if (!hg_state->timestamp)
> > > > > +			hg_state->timestamp =
> > > > > iio_get_time_ns(indio_dev);
> > > > > +
> > > > > +		hid_sensor_push_data(indio_dev, hg_state-
> > > > > >hinge_val,
> > > > > +				     sizeof(hg_state-
> > > > > >hinge_val),
> > > > > +				     hg_state->timestamp);
> > > > > +
> > > > > +		hg_state->timestamp = 0;
> > > > > +	}
> > > > > +
> > > > > +	return 0;
> > > > > +}
> > > > > +
> > > > > +/* Capture samples in local storage */
> > > > > +static int hinge_capture_sample(struct hid_sensor_hub_device
> > > > > *hsdev,
> > > > > +				unsigned int usage_id, size_t
> > > > > raw_len,
> > > > > +				char *raw_data, void *priv)
> > > > > +{
> > > > > +	struct hinge_state *hg_state;
> > > > > +	int offset;
> > > > > +	int ret = -EINVAL;
> > > > > +	int i;
> > > > > +
> > > > > +	if (usage_id == HID_USAGE_SENSOR_TIME_TIMESTAMP) {
> > > > > +		for (i = 0; i < IIO_DEV_NUM; i++)
> > > > > +			hg_group->hg_states[i]->timestamp =  
> > > > 
> > > > This rather implies all the data is captured together... If so
> > > > single
> > > > iio_device may make more sense.
> > > >   
> > > > > +				hid_sensor_convert_timestamp(
> > > > > +					&hg_group-
> > > > > >common_attributes,
> > > > > +					*(int64_t *)raw_data);
> > > > > +		return 0;
> > > > > +	}
> > > > > +
> > > > > +	switch (usage_id) {
> > > > > +	case HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_1:
> > > > > +	case HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_2:
> > > > > +	case HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_3:
> > > > > +		offset = usage_id -
> > > > > HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_1;
> > > > > +		hg_state = hg_group->hg_states[offset];
> > > > > +		hg_state->hinge_val[0] = *(u32 *)raw_data;
> > > > > +		ret = 0;  
> > > > 
> > > > 		return 0;
> > > >   
> > > > > +		break;
> > > > > +	default:  
> > > > 		return -EINVAL;  
> > > > > +		break;
> > > > > +	}
> > > > > +
> > > > > +	return ret;
> > > > > +}
> > > > > +
> > > > > +/* Parse report which is specific to an usage id */
> > > > > +static int hinge_parse_report(struct platform_device *pdev,
> > > > > +			      struct hid_sensor_hub_device
> > > > > *hsdev,
> > > > > +			      unsigned int usage_id, unsigned
> > > > > int
> > > > > attr_usage_id,
> > > > > +			      struct hinge_state *st)
> > > > > +{
> > > > > +	int ret;
> > > > > +
> > > > > +	ret = sensor_hub_input_get_attribute_info(
> > > > > +		hsdev, HID_INPUT_REPORT, usage_id,
> > > > > attr_usage_id, &st-  
> > > > > > hinge);  
> > > > > +	if (ret < 0)
> > > > > +		return ret;
> > > > > +
> > > > > +	st->hinge_address = attr_usage_id;
> > > > > +	st->scale_precision =
> > > > > +		hid_sensor_format_scale(HID_USAGE_SENSOR_HINGE,
> > > > > &st-  
> > > > > > hinge,  
> > > > > +					&st->scale_pre_decml,
> > > > > +					&st->scale_post_decml);
> > > > > +
> > > > > +	/* Set Sensitivity field ids, when there is no
> > > > > individual
> > > > > modifier */
> > > > > +	if (hg_group->common_attributes.sensitivity.index < 0)
> > > > > {
> > > > > +		sensor_hub_input_get_attribute_info(
> > > > > +			hsdev, HID_FEATURE_REPORT, usage_id,
> > > > > +			HID_USAGE_SENSOR_DATA_MOD_CHANGE_SENSIT
> > > > > IVITY_AB
> > > > > S |
> > > > > +				HID_USAGE_SENSOR_DATA_FIELD_CUS
> > > > > TOM_VALU
> > > > > E_1,
> > > > > +			&hg_group-
> > > > > >common_attributes.sensitivity);
> > > > > +		dev_dbg(&pdev->dev, "Sensitivity index:report
> > > > > %d:%d\n",
> > > > > +			hg_group-
> > > > > >common_attributes.sensitivity.index,
> > > > > +			hg_group-  
> > > > > > common_attributes.sensitivity.report_id);  
> > > > > +	}
> > > > > +
> > > > > +	return ret;
> > > > > +}
> > > > > +
> > > > > +/* Function to initialize the processing for usage id */
> > > > > +static int hinge_add_iio_device(struct platform_device
> > > > > *pdev,
> > > > > int
> > > > > index,
> > > > > +				const char *name, struct
> > > > > hinge_state
> > > > > **st)
> > > > > +{
> > > > > +	struct hid_sensor_hub_device *hsdev = pdev-
> > > > > >dev.platform_data;
> > > > > +	struct hinge_state *hg_state;
> > > > > +	struct iio_dev *indio_dev;
> > > > > +	int ret;
> > > > > +
> > > > > +	indio_dev =
> > > > > +		devm_iio_device_alloc(&pdev->dev, sizeof(struct
> > > > > hinge_state));  
> > > > 
> > > > sizeof (*hg_state) preferred.
> > > >   
> > > > > +	if (indio_dev == NULL)
> > > > > +		return -ENOMEM;
> > > > > +
> > > > > +	hg_state = iio_priv(indio_dev);
> > > > > +	hg_state->indio_dev = indio_dev;
> > > > > +
> > > > > +	indio_dev->num_channels = ARRAY_SIZE(hinge_channels);
> > > > > +	indio_dev->channels =
> > > > > +		kmemdup(hinge_channels, sizeof(hinge_channels),
> > > > > GFP_KERNEL);  
> > > > 
> > > > I don't immediately see anything that is modifying channels. As
> > > > such
> > > > you
> > > > should be able have it shared by all the instances.
> > > >   
> > > > > +	if (!indio_dev->channels)
> > > > > +		return -ENOMEM;
> > > > > +
> > > > > +	ret = hinge_parse_report(
> > > > > +		pdev, hsdev, hsdev->usage,
> > > > > +		HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_1 +
> > > > > index,
> > > > > hg_state);
> > > > > +	if (ret) {
> > > > > +		dev_err(&pdev->dev, "failed to setup
> > > > > attributes\n");
> > > > > +		goto error_free_dev_mem;
> > > > > +	}
> > > > > +
> > > > > +	indio_dev->dev.parent = &pdev->dev;
> > > > > +	indio_dev->info = &hinge_info;
> > > > > +	indio_dev->name = name;
> > > > > +	indio_dev->modes = INDIO_DIRECT_MODE;
> > > > > +
> > > > > +	ret = hid_sensor_setup_trigger(indio_dev, name,
> > > > > +				       &hg_group-
> > > > > >common_attributes);
> > > > > +	if (ret < 0) {
> > > > > +		dev_err(&pdev->dev, "trigger setup failed\n");
> > > > > +		goto error_free_dev_mem;
> > > > > +	}
> > > > > +
> > > > > +	ret = iio_device_register(indio_dev);
> > > > > +	if (ret) {
> > > > > +		dev_err(&pdev->dev, "device register
> > > > > failed\n");
> > > > > +		goto error_remove_trigger;
> > > > > +	}
> > > > > +
> > > > > +	*st = hg_state;
> > > > > +
> > > > > +	return ret;
> > > > > +
> > > > > +error_remove_trigger:
> > > > > +	hid_sensor_remove_trigger(indio_dev, &hg_group-  
> > > > > > common_attributes);  
> > > > > +error_free_dev_mem:
> > > > > +	kfree(indio_dev->channels);
> > > > > +	return ret;
> > > > > +}
> > > > > +
> > > > > +/* Function to deinitialize the processing for usage id */
> > > > > +static int hinge_remove_iio_device(struct platform_device
> > > > > *pdev,
> > > > > int index)
> > > > > +{
> > > > > +	struct hinge_state *hg_state = hg_group-
> > > > > >hg_states[index];
> > > > > +	struct iio_dev *indio_dev = hg_state->indio_dev;
> > > > > +
> > > > > +	iio_device_unregister(indio_dev);
> > > > > +	hid_sensor_remove_trigger(indio_dev, &hg_group-  
> > > > > > common_attributes);  
> > > > > +	kfree(indio_dev->channels);
> > > > > +
> > > > > +	return 0;
> > > > > +}
> > > > > +
> > > > > +static int hid_hinge_probe(struct platform_device *pdev)
> > > > > +{
> > > > > +	struct hinge_state *hg_state;
> > > > > +	struct hid_sensor_hub_device *hsdev = pdev-
> > > > > >dev.platform_data;
> > > > > +	static const char *const names[] = { "hinge", "screen",
> > > > > "keyboard" };
> > > > > +	int ret;
> > > > > +	int i;
> > > > > +
> > > > > +	hg_group = devm_kzalloc(&pdev->dev, sizeof(struct
> > > > > hinge_group),
> > > > > +				GFP_KERNEL);  
> > > > 
> > > > As mentioned above, I'd really not expect to see a global like
> > > > this.
> > > > Technically nothing stops there being more than one instance of
> > > > this
> > > > device on a platform (even if that would be a bit odd) + it's
> > > > almost
> > > > always cleaner to not use a global in the first place.
> > > >   
> > > > > +	if (!hg_group)
> > > > > +		return -ENOMEM;
> > > > > +
> > > > > +	hg_group->common_attributes.hsdev = hsdev;
> > > > > +	hg_group->common_attributes.pdev = pdev;
> > > > > +
> > > > > +	ret = hid_sensor_parse_common_attributes(hsdev, hsdev-
> > > > > >usage,
> > > > > +						 &hg_group-  
> > > > > > common_attributes);  
> > > > > +	if (ret) {
> > > > > +		dev_err(&pdev->dev, "failed to setup common
> > > > > attributes\n");
> > > > > +		return ret;
> > > > > +	}
> > > > > +
> > > > > +	atomic_set(&hg_group->common_attributes.data_ready, 0);
> > > > > +	for (i = 0; i < IIO_DEV_NUM; i++) {
> > > > > +		ret = hinge_add_iio_device(pdev, i, names[i],
> > > > > &hg_state);
> > > > > +		if (ret)
> > > > > +			goto err_probe;
> > > > > +
> > > > > +		hg_group->hg_states[i] = hg_state;
> > > > > +	}
> > > > > +
> > > > > +	/* use the first iio device to do the PM */
> > > > > +	platform_set_drvdata(pdev, hg_group->hg_states[0]-
> > > > > >indio_dev);
> > > > > +
> > > > > +	hg_group->callbacks.send_event = hinge_proc_event;
> > > > > +	hg_group->callbacks.capture_sample =
> > > > > hinge_capture_sample;
> > > > > +	hg_group->callbacks.pdev = pdev;
> > > > > +	ret = sensor_hub_register_callback(hsdev, hsdev->usage,
> > > > > +					   &hg_group-
> > > > > >callbacks);
> > > > > +	if (ret < 0)
> > > > > +		dev_err(&pdev->dev, "callback reg failed\n");
> > > > > +
> > > > > +	return ret;
> > > > > +
> > > > > +err_probe:
> > > > > +	for (i--; i >= 0; i--)
> > > > > +		hinge_remove_iio_device(pdev, i);
> > > > > +
> > > > > +	return ret;
> > > > > +}
> > > > > +
> > > > > +/* Function to deinitialize the processing for usage id */
> > > > > +static int hid_hinge_remove(struct platform_device *pdev)
> > > > > +{
> > > > > +	struct hid_sensor_hub_device *hsdev = pdev-
> > > > > >dev.platform_data;
> > > > > +	int i;
> > > > > +
> > > > > +	sensor_hub_remove_callback(hsdev, hsdev->usage);
> > > > > +
> > > > > +	for (i = 0; i < IIO_DEV_NUM; i++)
> > > > > +		hinge_remove_iio_device(pdev, i);
> > > > > +
> > > > > +	return 0;
> > > > > +}
> > > > > +
> > > > > +static const struct platform_device_id hid_hinge_ids[] = {
> > > > > +	{
> > > > > +		/* Format: HID-SENSOR-INT-
> > > > > usage_id_in_hex_lowercase */
> > > > > +		.name = "HID-SENSOR-INT-020b",
> > > > > +	},
> > > > > +	{ /* sentinel */ }
> > > > > +};
> > > > > +MODULE_DEVICE_TABLE(platform, hid_hinge_ids);
> > > > > +
> > > > > +static struct platform_driver hid_hinge_platform_driver = {
> > > > > +	.id_table = hid_hinge_ids,
> > > > > +	.driver = {
> > > > > +		.name	= KBUILD_MODNAME,
> > > > > +		.pm	= &hid_sensor_pm_ops,
> > > > > +	},
> > > > > +	.probe		= hid_hinge_probe,
> > > > > +	.remove		= hid_hinge_remove,
> > > > > +};
> > > > > +module_platform_driver(hid_hinge_platform_driver);
> > > > > +
> > > > > +MODULE_DESCRIPTION("HID Sensor Custom Hinge");
> > > > > +MODULE_AUTHOR("Ye Xiang <xiang.ye@intel.com>");
> > > > > +MODULE_LICENSE("GPL");

Jonathan Cameron Nov. 22, 2020, 4:50 p.m. UTC | #6

On Sun, 22 Nov 2020 15:51:18 +0000
"Pandruvada, Srinivas" <srinivas.pandruvada@intel.com> wrote:

> On Sun, 2020-11-22 at 14:14 +0000, Jonathan Cameron wrote:
> > On Sun, 22 Nov 2020 02:14:16 +0000
> > "Pandruvada, Srinivas" <srinivas.pandruvada@intel.com> wrote:
> >   
> > > On Sat, 2020-11-21 at 17:46 -0800, Srinivas Pandruvada wrote:  
> > > > On Sat, 2020-11-21 at 17:56 +0000, Jonathan Cameron wrote:    
> > > > > On Thu, 19 Nov 2020 18:03:31 +0800
> > > > > Ye Xiang <xiang.ye@intel.com> wrote:
> > > > >     
> > > > > > The Hinge sensor is a common custom sensor on laptops. It
> > > > > > calculates
> > > > > > the angle between the lid (screen) and the base (keyboard).
> > > > > > In
> > > > > > addition,
> > > > > > it also exposes screen and the keyboard angels with respect
> > > > > > to
> > > > > > the
> > > > > > ground. Applications can easily get laptop's status in space
> > > > > > through
> > > > > > this sensor, in order to display appropriate user
> > > > > > interface.    
> > > > > 
> > > > > I'm a little unclear on why the 3 axes aren't treated as a
> > > > > single
> > > > > sensor.
> > > > > You seem to always grab the 3 together or am I missing
> > > > > something?
> > > > > 
> > > > > That will greatly simplify things and get rid of the need to
> > > > > have
> > > > > a shared trigger with the problems that causes in the previous
> > > > > patch.    
> > > > 
> > > > They are not three axes, they are independent. Xiang did try
> > > > adding
> > > > x,
> > > > y and z component to represent x as hinge, y as keyboard and z as
> > > > lid.
> > > > But I was not convinced.
> > > > The problem is that then what will be sysfs interface? They are
> > > > really
> > > > a three sensors. Or we create new interface to call
> > > > in_angl_raw_keyboard
> > > > in_angl_raw_screen
> > > > in_angl_raw_lid.
> > > >     
> > > You seem to indicate this is possible now some new "label" patch.
> > > Is this the patch?
> > > commit 2c3d0c9ffd24d9b4c62c5dfb2104695a614be28c
> > > Author: Phil Reid <preid@electromag.com.au>
> > > Date:   Thu Sep 19 22:36:08 2019 +0800  
> > 
> > Nope, this one 
> > https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio.git/commit/?id=1d4ef9b39ebecca827642b8897d2d79ea2026682
> > 
> > The one above adds a per device label which wouldn't be much use for
> > your
> > case, but this one adds a per channel label.
> > 
> > Done via a read_label callback.
> > 
> > Here you'd want to use indexed channels so something like.
> > 
> > in_angl0_raw
> > in_angl1_raw
> > in_angl2_raw
> > 
> > and
> > 
> > in_angl0_label = keyboard
> > in_angl1_label = screen
> > in_angl2_label = lid  
> 
> Thanks Jonathan. This will make the job easier.
> Xiang,
> You can use this method. Then you will not need other changes except
> patch 1/4.
> Also add a documentation patch to explain the mapping.

Ah.  So we have a slightly problem with sysfs ABI docs at the moment.
The scripts that auto generate the html and similar docs from them
don't cope with the same name of attribute in multiple documentation
files.

https://lore.kernel.org/linux-iio/20201110082658.2edc1ab5@coco.lan/

The upshot being we can't have more specific docs for a particular
part that match up with the generic docs.  That will apply in this
case.

So for now, our solution is to put it in the main docs, but provide
a subsection in there talking about more specific constraints for
a particular device.

Note I haven't actually proposed any fixes for this problem yet so
you get to do the first one ;)

Thanks,

Jonathan



> 
> Thanks,
> Srinivas
> 
> > 
> > 
> >   
> > > Ideally, one iio device here is much easy to manage as other HID
> > > sensors. If we can add something other that "x", "y" and "z"
> > > component.  
> > 
> > Agreed, using axes makes no real sense here and extended_name is
> > just a mess from ABI point of view.  Trying to solve this was the
> > reason we added the _label interface.
> > 
> > Jonathan
> > 
> >   
> > > Thanks,
> > > Srinivas
> > >   
> > > > Thanks,
> > > > Srinivas
> > > > 
> > > >     
> > > > > Thanks,
> > > > > 
> > > > > Jonathan
> > > > >     
> > > > > > Signed-off-by: Ye Xiang <xiang.ye@intel.com>
> > > > > > ---
> > > > > >  .../hid-sensors/hid-sensor-attributes.c       |   2 +
> > > > > >  drivers/iio/position/Kconfig                  |  16 +
> > > > > >  drivers/iio/position/Makefile                 |   3 +
> > > > > >  .../iio/position/hid-sensor-custom-hinge.c    | 412
> > > > > > ++++++++++++++++++    
> > > > > 
> > > > > Given it's custom probably needs a more specific name.  I guess
> > > > > hid-sensor-custom-intel-hinge.c might be safe?
> > > > > 
> > > > > Same for other places we need names in here.
> > > > >     
> > > > > >  4 files changed, 433 insertions(+)
> > > > > >  create mode 100644 drivers/iio/position/hid-sensor-custom-
> > > > > > hinge.c
> > > > > > 
> > > > > > diff --git a/drivers/iio/common/hid-sensors/hid-sensor-
> > > > > > attributes.c 
> > > > > > b/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> > > > > > index 442ff787f7af..5b822a4298a0 100644
> > > > > > --- a/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> > > > > > +++ b/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> > > > > > @@ -71,6 +71,8 @@ static struct {
> > > > > >  	{HID_USAGE_SENSOR_TEMPERATURE,
> > > > > > HID_USAGE_SENSOR_UNITS_DEGREES,
> > > > > > 1000, 0},
> > > > > >  
> > > > > >  	{HID_USAGE_SENSOR_HUMIDITY, 0, 1000, 0},
> > > > > > +	{HID_USAGE_SENSOR_HINGE, 0, 0, 17453293},
> > > > > > +	{HID_USAGE_SENSOR_HINGE,
> > > > > > HID_USAGE_SENSOR_UNITS_DEGREES, 0,
> > > > > > 17453293},
> > > > > >  };
> > > > > >  
> > > > > >  static void simple_div(int dividend, int divisor, int
> > > > > > *whole,
> > > > > > diff --git a/drivers/iio/position/Kconfig
> > > > > > b/drivers/iio/position/Kconfig
> > > > > > index eda67f008c5b..0346f6f2b422 100644
> > > > > > --- a/drivers/iio/position/Kconfig
> > > > > > +++ b/drivers/iio/position/Kconfig
> > > > > > @@ -16,4 +16,20 @@ config IQS624_POS
> > > > > >  	  To compile this driver as a module, choose M here:
> > > > > > the module
> > > > > >  	  will be called iqs624-pos.
> > > > > >  
> > > > > > +config HID_SENSOR_CUSTOM_HINGE
> > > > > > +	depends on HID_SENSOR_HUB
> > > > > > +	select IIO_BUFFER
> > > > > > +	select IIO_TRIGGERED_BUFFER
> > > > > > +	select HID_SENSOR_IIO_COMMON
> > > > > > +	select HID_SENSOR_IIO_TRIGGER
> > > > > > +	tristate "HID Hinge"
> > > > > > +	help
> > > > > > +	  This sensor present three angles, hinge angel, screen
> > > > > > angles
> > > > > > +	  and keyboard angle respect to horizon (ground).
> > > > > > +	  Say yes here to build support for the HID SENSOR
> > > > > > CUSTOM
> > > > > > +	  HINGE.    
> > > > > 
> > > > > Capitalization is a bit odd looking. I'd drop it.
> > > > >     
> > > > > > +
> > > > > > +	  To compile this driver as a module, choose M here:
> > > > > > the
> > > > > > +	  module will be called hid-sensor-custom-hinge.
> > > > > > +
> > > > > >  endmenu
> > > > > > diff --git a/drivers/iio/position/Makefile
> > > > > > b/drivers/iio/position/Makefile
> > > > > > index 3cbe7a734352..7a6225977a01 100644
> > > > > > --- a/drivers/iio/position/Makefile
> > > > > > +++ b/drivers/iio/position/Makefile
> > > > > > @@ -5,3 +5,6 @@
> > > > > >  # When adding new entries keep the list in alphabetical
> > > > > > order
> > > > > >  
> > > > > >  obj-$(CONFIG_IQS624_POS)	+= iqs624-pos.o
> > > > > > +
> > > > > > +obj-$(CONFIG_HID_SENSOR_CUSTOM_HINGE) += hid-sensor-custom-
> > > > > > hinge.o    
> > > > > 
> > > > > Alphabetical order preferred.
> > > > >     
> > > > > > +ccflags-y	+= -I$(srctree)/drivers/iio/common/hid-
> > > > > > sensors    
> > > > > 
> > > > > Why?
> > > > >     
> > > > > > diff --git a/drivers/iio/position/hid-sensor-custom-hinge.c
> > > > > > b/drivers/iio/position/hid-sensor-custom-hinge.c
> > > > > > new file mode 100644
> > > > > > index 000000000000..a91b333f36fa
> > > > > > --- /dev/null
> > > > > > +++ b/drivers/iio/position/hid-sensor-custom-hinge.c
> > > > > > @@ -0,0 +1,412 @@
> > > > > > +// SPDX-License-Identifier: GPL-2.0-only
> > > > > > +/*
> > > > > > + * HID Sensors Driver
> > > > > > + * Copyright (c) 2020, Intel Corporation.
> > > > > > + */
> > > > > > +#include <linux/hid-sensor-hub.h>
> > > > > > +#include <linux/iio/buffer.h>
> > > > > > +#include <linux/iio/iio.h>
> > > > > > +#include <linux/platform_device.h>
> > > > > > +
> > > > > > +#include "hid-sensor-trigger.h"
> > > > > > +
> > > > > > +/* Channel definitions */
> > > > > > +static const struct iio_chan_spec hinge_channels[] = {
> > > > > > +	{ .type = IIO_ANGL,
> > > > > > +	  .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> > > > > > +	  .info_mask_shared_by_type =
> > > > > > +		  BIT(IIO_CHAN_INFO_OFFSET) |
> > > > > > BIT(IIO_CHAN_INFO_SCALE)
> > > > > > +		  BIT(IIO_CHAN_INFO_SAMP_FREQ) |
> > > > > > BIT(IIO_CHAN_INFO_HYSTERESIS),
> > > > > > +	  .scan_type.realbits = 16,
> > > > > > +	  .scan_type.storagebits = 32,    
> > > > > 
> > > > > It a bit odd to see a single channel that is 16 bits inside a
> > > > > 32
> > > > > bit
> > > > > with
> > > > > no shift or similar.  Why not just pack it into 16 bits?
> > > > >     
> > > > > > +	  .scan_type.sign = 's',
> > > > > > +	  .scan_index = 0 },
> > > > > > +
> > > > > > +	IIO_CHAN_SOFT_TIMESTAMP(1)
> > > > > > +};
> > > > > > +
> > > > > > +struct hinge_state {
> > > > > > +	struct iio_dev *indio_dev;
> > > > > > +	struct hid_sensor_hub_attribute_info hinge;
> > > > > > +	/* Reserve for 1 channel + pading + timestamp */
> > > > > > +	u32 hinge_val[1 + 3];    
> > > > > 
> > > > > __aligned(8)
> > > > > 
> > > > > see below for requirements on this.
> > > > > Perhaps better to use
> > > > > 
> > > > > 	struct hinge_scan {
> > > > > 		u32 val;
> > > > > 		s64 timestamp __aligned(8); // Note this is
> > > > > needed for
> > > > > x86_32
> > > > > 	} scan;
> > > > >     
> > > > > > +	int scale_pre_decml;
> > > > > > +	int scale_post_decml;
> > > > > > +	int scale_precision;
> > > > > > +	int value_offset;
> > > > > > +	int64_t timestamp;
> > > > > > +	u32 hinge_address;
> > > > > > +};
> > > > > > +
> > > > > > +#define IIO_DEV_NUM 3    
> > > > > 
> > > > > That needs a prefix to make it clear it's not a generic
> > > > > constant
> > > > > but is specific to this driver.
> > > > >     
> > > > > > +
> > > > > > +struct hinge_group {
> > > > > > +	struct hinge_state *hg_states[IIO_DEV_NUM];
> > > > > > +	struct hid_sensor_hub_callbacks callbacks;
> > > > > > +	struct hid_sensor_common common_attributes;
> > > > > > +};
> > > > > > +
> > > > > > +static struct hinge_group *hg_group;    
> > > > > 
> > > > > We shouldn't see globals like this. Please figure out how to
> > > > > avoid
> > > > > it.
> > > > >     
> > > > > > +
> > > > > > +/* Channel read_raw handler */
> > > > > > +static int hinge_read_raw(struct iio_dev *indio_dev,
> > > > > > +			  struct iio_chan_spec const *chan, int
> > > > > > *val,
> > > > > > int *val2,
> > > > > > +			  long mask)
> > > > > > +{
> > > > > > +	struct hinge_state *hg_state = iio_priv(indio_dev);
> > > > > > +	struct hid_sensor_hub_device *hsdev;
> > > > > > +	int report_id = -1;
> > > > > > +	int ret_type;
> > > > > > +	s32 min;
> > > > > > +
> > > > > > +	hsdev = hg_group->common_attributes.hsdev;
> > > > > > +
> > > > > > +	*val = 0;
> > > > > > +	*val2 = 0;
> > > > > > +	switch (mask) {
> > > > > > +	case IIO_CHAN_INFO_RAW:
> > > > > > +		hid_sensor_power_state(&hg_group-  
> > > > > > >common_attributes,  
> > > > > > true);
> > > > > > +		report_id = hg_state->hinge.report_id;
> > > > > > +		min = hg_state->hinge.logical_minimum;
> > > > > > +		if (report_id < 0) {
> > > > > > +			*val = 0;
> > > > > > +			hid_sensor_power_state(&hg_group-    
> > > > > > > common_attributes,    
> > > > > > +					       false);
> > > > > > +			return -EINVAL;
> > > > > > +		}
> > > > > > +
> > > > > > +		*val = sensor_hub_input_attr_get_raw_value(
> > > > > > +			hg_group->common_attributes.hsdev,
> > > > > > hsdev-    
> > > > > > > usage,    
> > > > > > +			hg_state->hinge_address, report_id,
> > > > > > SENSOR_HUB_SYNC,
> > > > > > +			min < 0);
> > > > > > +
> > > > > > +		hid_sensor_power_state(&hg_group-  
> > > > > > >common_attributes,  
> > > > > > false);
> > > > > > +		ret_type = IIO_VAL_INT;
> > > > > > +		break;
> > > > > > +	case IIO_CHAN_INFO_SCALE:
> > > > > > +		*val = hg_state->scale_pre_decml;
> > > > > > +		*val2 = hg_state->scale_post_decml;
> > > > > > +		ret_type = hg_state->scale_precision;
> > > > > > +		break;
> > > > > > +	case IIO_CHAN_INFO_OFFSET:
> > > > > > +		*val = hg_state->value_offset;
> > > > > > +		ret_type = IIO_VAL_INT;
> > > > > > +		break;
> > > > > > +	case IIO_CHAN_INFO_SAMP_FREQ:
> > > > > > +		ret_type = hid_sensor_read_samp_freq_value(
> > > > > > +			&hg_group->common_attributes, val,
> > > > > > val2);
> > > > > > +		break;
> > > > > > +	case IIO_CHAN_INFO_HYSTERESIS:
> > > > > > +		ret_type = hid_sensor_read_raw_hyst_value(
> > > > > > +			&hg_group->common_attributes, val,
> > > > > > val2);
> > > > > > +		break;
> > > > > > +	default:
> > > > > > +		ret_type = -EINVAL;
> > > > > > +		break;
> > > > > > +	}
> > > > > > +
> > > > > > +	return ret_type;
> > > > > > +}
> > > > > > +
> > > > > > +/* Channel write_raw handler */
> > > > > > +static int hinge_write_raw(struct iio_dev *indio_dev,
> > > > > > +			   struct iio_chan_spec const *chan,
> > > > > > int val,
> > > > > > int val2,
> > > > > > +			   long mask)
> > > > > > +{
> > > > > > +	int ret;
> > > > > > +
> > > > > > +	switch (mask) {
> > > > > > +	case IIO_CHAN_INFO_SAMP_FREQ:
> > > > > > +		ret = hid_sensor_write_samp_freq_value(
> > > > > > +			&hg_group->common_attributes, val,
> > > > > > val2);
> > > > > > +		break;
> > > > > > +	case IIO_CHAN_INFO_HYSTERESIS:
> > > > > > +		ret = hid_sensor_write_raw_hyst_value(
> > > > > > +			&hg_group->common_attributes, val,
> > > > > > val2);
> > > > > > +
> > > > > > +		break;
> > > > > > +	default:
> > > > > > +		ret = -EINVAL;
> > > > > > +	}
> > > > > > +
> > > > > > +	return ret;
> > > > > > +}
> > > > > > +
> > > > > > +static const struct iio_info hinge_info = {
> > > > > > +	.read_raw = &hinge_read_raw,
> > > > > > +	.write_raw = &hinge_write_raw,
> > > > > > +};
> > > > > > +
> > > > > > +/*
> > > > > > + * Function to push data to buffer;
> > > > > > + * wrapper added for symmetry with other hid-sensor drivers
> > > > > > + */
> > > > > > +static void hid_sensor_push_data(struct iio_dev *indio_dev,
> > > > > > void
> > > > > > *data, int len,    
> > > > > 
> > > > > This doesn't seem to be generic, so don't name it as such.
> > > > >     
> > > > > > +				 int64_t timestamp)
> > > > > > +{
> > > > > > +	iio_push_to_buffers_with_timestamp(indio_dev, data,
> > > > > > timestamp);    
> > > > > I hope that data buffer obeys the various rules needed by (and
> > > > > admittedly
> > > > > not that well documented) iio_push_to_buffers_with_timestamp()
> > > > > 
> > > > > 1. Needs to be 8 byte aligned.
> > > > > 2. Needs to have space for an aligned 8 byte timestamp at the
> > > > > end.
> > > > >     
> > > > > > +}
> > > > > > +
> > > > > > +/*
> > > > > > + * Callback handler to send event after all samples are
> > > > > > received
> > > > > > + * and captured.
> > > > > > + */
> > > > > > +static int hinge_proc_event(struct hid_sensor_hub_device
> > > > > > *hsdev,
> > > > > > +			    unsigned int usage_id, void *priv)
> > > > > > +{
> > > > > > +	int i;
> > > > > > +
> > > > > > +	for (i = 0; i < IIO_DEV_NUM; ++i) {    
> > > > > If we push for all sensors together, better to have
> > > > > this as a single iio_device with 3 channels.
> > > > > 
> > > > > Use the channel labels (just added to IIO) to identify which is
> > > > > which.
> > > > >     
> > > > > > +		struct hinge_state *hg_state;
> > > > > > +		struct iio_dev *indio_dev;
> > > > > > +
> > > > > > +		hg_state = hg_group->hg_states[i];
> > > > > > +		indio_dev = hg_state->indio_dev;
> > > > > > +
> > > > > > +		dev_dbg(&indio_dev->dev, "%s timestamp:%llu
> > > > > > scan_bytes:%d\n",
> > > > > > +			__func__, hg_state->timestamp,
> > > > > > indio_dev-    
> > > > > > > scan_bytes);    
> > > > > > +
> > > > > > +		if (!hg_state->timestamp)
> > > > > > +			hg_state->timestamp =
> > > > > > iio_get_time_ns(indio_dev);
> > > > > > +
> > > > > > +		hid_sensor_push_data(indio_dev, hg_state-  
> > > > > > >hinge_val,  
> > > > > > +				     sizeof(hg_state-  
> > > > > > >hinge_val),  
> > > > > > +				     hg_state->timestamp);
> > > > > > +
> > > > > > +		hg_state->timestamp = 0;
> > > > > > +	}
> > > > > > +
> > > > > > +	return 0;
> > > > > > +}
> > > > > > +
> > > > > > +/* Capture samples in local storage */
> > > > > > +static int hinge_capture_sample(struct hid_sensor_hub_device
> > > > > > *hsdev,
> > > > > > +				unsigned int usage_id, size_t
> > > > > > raw_len,
> > > > > > +				char *raw_data, void *priv)
> > > > > > +{
> > > > > > +	struct hinge_state *hg_state;
> > > > > > +	int offset;
> > > > > > +	int ret = -EINVAL;
> > > > > > +	int i;
> > > > > > +
> > > > > > +	if (usage_id == HID_USAGE_SENSOR_TIME_TIMESTAMP) {
> > > > > > +		for (i = 0; i < IIO_DEV_NUM; i++)
> > > > > > +			hg_group->hg_states[i]->timestamp =    
> > > > > 
> > > > > This rather implies all the data is captured together... If so
> > > > > single
> > > > > iio_device may make more sense.
> > > > >     
> > > > > > +				hid_sensor_convert_timestamp(
> > > > > > +					&hg_group-  
> > > > > > >common_attributes,  
> > > > > > +					*(int64_t *)raw_data);
> > > > > > +		return 0;
> > > > > > +	}
> > > > > > +
> > > > > > +	switch (usage_id) {
> > > > > > +	case HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_1:
> > > > > > +	case HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_2:
> > > > > > +	case HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_3:
> > > > > > +		offset = usage_id -
> > > > > > HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_1;
> > > > > > +		hg_state = hg_group->hg_states[offset];
> > > > > > +		hg_state->hinge_val[0] = *(u32 *)raw_data;
> > > > > > +		ret = 0;    
> > > > > 
> > > > > 		return 0;
> > > > >     
> > > > > > +		break;
> > > > > > +	default:    
> > > > > 		return -EINVAL;    
> > > > > > +		break;
> > > > > > +	}
> > > > > > +
> > > > > > +	return ret;
> > > > > > +}
> > > > > > +
> > > > > > +/* Parse report which is specific to an usage id */
> > > > > > +static int hinge_parse_report(struct platform_device *pdev,
> > > > > > +			      struct hid_sensor_hub_device
> > > > > > *hsdev,
> > > > > > +			      unsigned int usage_id, unsigned
> > > > > > int
> > > > > > attr_usage_id,
> > > > > > +			      struct hinge_state *st)
> > > > > > +{
> > > > > > +	int ret;
> > > > > > +
> > > > > > +	ret = sensor_hub_input_get_attribute_info(
> > > > > > +		hsdev, HID_INPUT_REPORT, usage_id,
> > > > > > attr_usage_id, &st-    
> > > > > > > hinge);    
> > > > > > +	if (ret < 0)
> > > > > > +		return ret;
> > > > > > +
> > > > > > +	st->hinge_address = attr_usage_id;
> > > > > > +	st->scale_precision =
> > > > > > +		hid_sensor_format_scale(HID_USAGE_SENSOR_HINGE,
> > > > > > &st-    
> > > > > > > hinge,    
> > > > > > +					&st->scale_pre_decml,
> > > > > > +					&st->scale_post_decml);
> > > > > > +
> > > > > > +	/* Set Sensitivity field ids, when there is no
> > > > > > individual
> > > > > > modifier */
> > > > > > +	if (hg_group->common_attributes.sensitivity.index < 0)
> > > > > > {
> > > > > > +		sensor_hub_input_get_attribute_info(
> > > > > > +			hsdev, HID_FEATURE_REPORT, usage_id,
> > > > > > +			HID_USAGE_SENSOR_DATA_MOD_CHANGE_SENSIT
> > > > > > IVITY_AB
> > > > > > S |
> > > > > > +				HID_USAGE_SENSOR_DATA_FIELD_CUS
> > > > > > TOM_VALU
> > > > > > E_1,
> > > > > > +			&hg_group-  
> > > > > > >common_attributes.sensitivity);  
> > > > > > +		dev_dbg(&pdev->dev, "Sensitivity index:report
> > > > > > %d:%d\n",
> > > > > > +			hg_group-  
> > > > > > >common_attributes.sensitivity.index,  
> > > > > > +			hg_group-    
> > > > > > > common_attributes.sensitivity.report_id);    
> > > > > > +	}
> > > > > > +
> > > > > > +	return ret;
> > > > > > +}
> > > > > > +
> > > > > > +/* Function to initialize the processing for usage id */
> > > > > > +static int hinge_add_iio_device(struct platform_device
> > > > > > *pdev,
> > > > > > int
> > > > > > index,
> > > > > > +				const char *name, struct
> > > > > > hinge_state
> > > > > > **st)
> > > > > > +{
> > > > > > +	struct hid_sensor_hub_device *hsdev = pdev-  
> > > > > > >dev.platform_data;  
> > > > > > +	struct hinge_state *hg_state;
> > > > > > +	struct iio_dev *indio_dev;
> > > > > > +	int ret;
> > > > > > +
> > > > > > +	indio_dev =
> > > > > > +		devm_iio_device_alloc(&pdev->dev, sizeof(struct
> > > > > > hinge_state));    
> > > > > 
> > > > > sizeof (*hg_state) preferred.
> > > > >     
> > > > > > +	if (indio_dev == NULL)
> > > > > > +		return -ENOMEM;
> > > > > > +
> > > > > > +	hg_state = iio_priv(indio_dev);
> > > > > > +	hg_state->indio_dev = indio_dev;
> > > > > > +
> > > > > > +	indio_dev->num_channels = ARRAY_SIZE(hinge_channels);
> > > > > > +	indio_dev->channels =
> > > > > > +		kmemdup(hinge_channels, sizeof(hinge_channels),
> > > > > > GFP_KERNEL);    
> > > > > 
> > > > > I don't immediately see anything that is modifying channels. As
> > > > > such
> > > > > you
> > > > > should be able have it shared by all the instances.
> > > > >     
> > > > > > +	if (!indio_dev->channels)
> > > > > > +		return -ENOMEM;
> > > > > > +
> > > > > > +	ret = hinge_parse_report(
> > > > > > +		pdev, hsdev, hsdev->usage,
> > > > > > +		HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_1 +
> > > > > > index,
> > > > > > hg_state);
> > > > > > +	if (ret) {
> > > > > > +		dev_err(&pdev->dev, "failed to setup
> > > > > > attributes\n");
> > > > > > +		goto error_free_dev_mem;
> > > > > > +	}
> > > > > > +
> > > > > > +	indio_dev->dev.parent = &pdev->dev;
> > > > > > +	indio_dev->info = &hinge_info;
> > > > > > +	indio_dev->name = name;
> > > > > > +	indio_dev->modes = INDIO_DIRECT_MODE;
> > > > > > +
> > > > > > +	ret = hid_sensor_setup_trigger(indio_dev, name,
> > > > > > +				       &hg_group-  
> > > > > > >common_attributes);  
> > > > > > +	if (ret < 0) {
> > > > > > +		dev_err(&pdev->dev, "trigger setup failed\n");
> > > > > > +		goto error_free_dev_mem;
> > > > > > +	}
> > > > > > +
> > > > > > +	ret = iio_device_register(indio_dev);
> > > > > > +	if (ret) {
> > > > > > +		dev_err(&pdev->dev, "device register
> > > > > > failed\n");
> > > > > > +		goto error_remove_trigger;
> > > > > > +	}
> > > > > > +
> > > > > > +	*st = hg_state;
> > > > > > +
> > > > > > +	return ret;
> > > > > > +
> > > > > > +error_remove_trigger:
> > > > > > +	hid_sensor_remove_trigger(indio_dev, &hg_group-    
> > > > > > > common_attributes);    
> > > > > > +error_free_dev_mem:
> > > > > > +	kfree(indio_dev->channels);
> > > > > > +	return ret;
> > > > > > +}
> > > > > > +
> > > > > > +/* Function to deinitialize the processing for usage id */
> > > > > > +static int hinge_remove_iio_device(struct platform_device
> > > > > > *pdev,
> > > > > > int index)
> > > > > > +{
> > > > > > +	struct hinge_state *hg_state = hg_group-  
> > > > > > >hg_states[index];  
> > > > > > +	struct iio_dev *indio_dev = hg_state->indio_dev;
> > > > > > +
> > > > > > +	iio_device_unregister(indio_dev);
> > > > > > +	hid_sensor_remove_trigger(indio_dev, &hg_group-    
> > > > > > > common_attributes);    
> > > > > > +	kfree(indio_dev->channels);
> > > > > > +
> > > > > > +	return 0;
> > > > > > +}
> > > > > > +
> > > > > > +static int hid_hinge_probe(struct platform_device *pdev)
> > > > > > +{
> > > > > > +	struct hinge_state *hg_state;
> > > > > > +	struct hid_sensor_hub_device *hsdev = pdev-  
> > > > > > >dev.platform_data;  
> > > > > > +	static const char *const names[] = { "hinge", "screen",
> > > > > > "keyboard" };
> > > > > > +	int ret;
> > > > > > +	int i;
> > > > > > +
> > > > > > +	hg_group = devm_kzalloc(&pdev->dev, sizeof(struct
> > > > > > hinge_group),
> > > > > > +				GFP_KERNEL);    
> > > > > 
> > > > > As mentioned above, I'd really not expect to see a global like
> > > > > this.
> > > > > Technically nothing stops there being more than one instance of
> > > > > this
> > > > > device on a platform (even if that would be a bit odd) + it's
> > > > > almost
> > > > > always cleaner to not use a global in the first place.
> > > > >     
> > > > > > +	if (!hg_group)
> > > > > > +		return -ENOMEM;
> > > > > > +
> > > > > > +	hg_group->common_attributes.hsdev = hsdev;
> > > > > > +	hg_group->common_attributes.pdev = pdev;
> > > > > > +
> > > > > > +	ret = hid_sensor_parse_common_attributes(hsdev, hsdev-  
> > > > > > >usage,  
> > > > > > +						 &hg_group-    
> > > > > > > common_attributes);    
> > > > > > +	if (ret) {
> > > > > > +		dev_err(&pdev->dev, "failed to setup common
> > > > > > attributes\n");
> > > > > > +		return ret;
> > > > > > +	}
> > > > > > +
> > > > > > +	atomic_set(&hg_group->common_attributes.data_ready, 0);
> > > > > > +	for (i = 0; i < IIO_DEV_NUM; i++) {
> > > > > > +		ret = hinge_add_iio_device(pdev, i, names[i],
> > > > > > &hg_state);
> > > > > > +		if (ret)
> > > > > > +			goto err_probe;
> > > > > > +
> > > > > > +		hg_group->hg_states[i] = hg_state;
> > > > > > +	}
> > > > > > +
> > > > > > +	/* use the first iio device to do the PM */
> > > > > > +	platform_set_drvdata(pdev, hg_group->hg_states[0]-  
> > > > > > >indio_dev);  
> > > > > > +
> > > > > > +	hg_group->callbacks.send_event = hinge_proc_event;
> > > > > > +	hg_group->callbacks.capture_sample =
> > > > > > hinge_capture_sample;
> > > > > > +	hg_group->callbacks.pdev = pdev;
> > > > > > +	ret = sensor_hub_register_callback(hsdev, hsdev->usage,
> > > > > > +					   &hg_group-  
> > > > > > >callbacks);  
> > > > > > +	if (ret < 0)
> > > > > > +		dev_err(&pdev->dev, "callback reg failed\n");
> > > > > > +
> > > > > > +	return ret;
> > > > > > +
> > > > > > +err_probe:
> > > > > > +	for (i--; i >= 0; i--)
> > > > > > +		hinge_remove_iio_device(pdev, i);
> > > > > > +
> > > > > > +	return ret;
> > > > > > +}
> > > > > > +
> > > > > > +/* Function to deinitialize the processing for usage id */
> > > > > > +static int hid_hinge_remove(struct platform_device *pdev)
> > > > > > +{
> > > > > > +	struct hid_sensor_hub_device *hsdev = pdev-  
> > > > > > >dev.platform_data;  
> > > > > > +	int i;
> > > > > > +
> > > > > > +	sensor_hub_remove_callback(hsdev, hsdev->usage);
> > > > > > +
> > > > > > +	for (i = 0; i < IIO_DEV_NUM; i++)
> > > > > > +		hinge_remove_iio_device(pdev, i);
> > > > > > +
> > > > > > +	return 0;
> > > > > > +}
> > > > > > +
> > > > > > +static const struct platform_device_id hid_hinge_ids[] = {
> > > > > > +	{
> > > > > > +		/* Format: HID-SENSOR-INT-
> > > > > > usage_id_in_hex_lowercase */
> > > > > > +		.name = "HID-SENSOR-INT-020b",
> > > > > > +	},
> > > > > > +	{ /* sentinel */ }
> > > > > > +};
> > > > > > +MODULE_DEVICE_TABLE(platform, hid_hinge_ids);
> > > > > > +
> > > > > > +static struct platform_driver hid_hinge_platform_driver = {
> > > > > > +	.id_table = hid_hinge_ids,
> > > > > > +	.driver = {
> > > > > > +		.name	= KBUILD_MODNAME,
> > > > > > +		.pm	= &hid_sensor_pm_ops,
> > > > > > +	},
> > > > > > +	.probe		= hid_hinge_probe,
> > > > > > +	.remove		= hid_hinge_remove,
> > > > > > +};
> > > > > > +module_platform_driver(hid_hinge_platform_driver);
> > > > > > +
> > > > > > +MODULE_DESCRIPTION("HID Sensor Custom Hinge");
> > > > > > +MODULE_AUTHOR("Ye Xiang <xiang.ye@intel.com>");
> > > > > > +MODULE_LICENSE("GPL");

Ye Xiang Nov. 24, 2020, 3:30 a.m. UTC | #7

On Sun, Nov 22, 2020 at 04:50:47PM +0000, Jonathan Cameron wrote:
> On Sun, 22 Nov 2020 15:51:18 +0000
> "Pandruvada, Srinivas" <srinivas.pandruvada@intel.com> wrote:
> 
> > On Sun, 2020-11-22 at 14:14 +0000, Jonathan Cameron wrote:
> > > On Sun, 22 Nov 2020 02:14:16 +0000
> > > "Pandruvada, Srinivas" <srinivas.pandruvada@intel.com> wrote:
> > >   
> > > > On Sat, 2020-11-21 at 17:46 -0800, Srinivas Pandruvada wrote:  
> > > > > On Sat, 2020-11-21 at 17:56 +0000, Jonathan Cameron wrote:    
> > > > > > On Thu, 19 Nov 2020 18:03:31 +0800
> > > > > > Ye Xiang <xiang.ye@intel.com> wrote:
> > > > > >     
> > > > > > > The Hinge sensor is a common custom sensor on laptops. It
> > > > > > > calculates
> > > > > > > the angle between the lid (screen) and the base (keyboard).
> > > > > > > In
> > > > > > > addition,
> > > > > > > it also exposes screen and the keyboard angels with respect
> > > > > > > to
> > > > > > > the
> > > > > > > ground. Applications can easily get laptop's status in space
> > > > > > > through
> > > > > > > this sensor, in order to display appropriate user
> > > > > > > interface.    
> > > > > > 
> > > > > > I'm a little unclear on why the 3 axes aren't treated as a
> > > > > > single
> > > > > > sensor.
> > > > > > You seem to always grab the 3 together or am I missing
> > > > > > something?
> > > > > > 
> > > > > > That will greatly simplify things and get rid of the need to
> > > > > > have
> > > > > > a shared trigger with the problems that causes in the previous
> > > > > > patch.    
> > > > > 
> > > > > They are not three axes, they are independent. Xiang did try
> > > > > adding
> > > > > x,
> > > > > y and z component to represent x as hinge, y as keyboard and z as
> > > > > lid.
> > > > > But I was not convinced.
> > > > > The problem is that then what will be sysfs interface? They are
> > > > > really
> > > > > a three sensors. Or we create new interface to call
> > > > > in_angl_raw_keyboard
> > > > > in_angl_raw_screen
> > > > > in_angl_raw_lid.
> > > > >     
> > > > You seem to indicate this is possible now some new "label" patch.
> > > > Is this the patch?
> > > > commit 2c3d0c9ffd24d9b4c62c5dfb2104695a614be28c
> > > > Author: Phil Reid <preid@electromag.com.au>
> > > > Date:   Thu Sep 19 22:36:08 2019 +0800  
> > > 
> > > Nope, this one 
> > > https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio.git/commit/?id=1d4ef9b39ebecca827642b8897d2d79ea2026682
> > > 
> > > The one above adds a per device label which wouldn't be much use for
> > > your
> > > case, but this one adds a per channel label.
> > > 
> > > Done via a read_label callback.
> > > 
> > > Here you'd want to use indexed channels so something like.
> > > 
> > > in_angl0_raw
> > > in_angl1_raw
> > > in_angl2_raw
> > > 
> > > and
> > > 
> > > in_angl0_label = keyboard
> > > in_angl1_label = screen
> > > in_angl2_label = lid  
> > 
> > Thanks Jonathan. This will make the job easier.
> > Xiang,
> > You can use this method. Then you will not need other changes except
> > patch 1/4.
> > Also add a documentation patch to explain the mapping.
> 
> Ah.  So we have a slightly problem with sysfs ABI docs at the moment.
> The scripts that auto generate the html and similar docs from them
> don't cope with the same name of attribute in multiple documentation
> files.
> 
> https://lore.kernel.org/linux-iio/20201110082658.2edc1ab5@coco.lan/
> 
> The upshot being we can't have more specific docs for a particular
> part that match up with the generic docs.  That will apply in this
> case.
> 
> So for now, our solution is to put it in the main docs, but provide
> a subsection in there talking about more specific constraints for
> a particular device.
> 
> Note I haven't actually proposed any fixes for this problem yet so
> you get to do the first one ;)
> 
> Thanks,
> 
> Jonathan
@Srinivas
Yes, I will try this indexed channel and label based method.

@Jonathan
So, I need to add in_angl0_raw, in_angl1_raw, in_angl2_raw and in_angl0_label,
in_angl1_label,in_angl2_label description in sysfs-bus-iio. such as

What:		/sys/bus/iio/devices/iio:deviceX/in_angl0_raw
What:		/sys/bus/iio/devices/iio:deviceX/in_angl1_raw
What:		/sys/bus/iio/devices/iio:deviceX/in_angl2_raw
KernelVersion:	5.12
Contact:	linux-iio@vger.kernel.org
Description:
		Angle of rotation. Units after application of scale and offset
		are radians.

What:		/sys/bus/iio/devices/iio:deviceX/in_angl0_label
What:		/sys/bus/iio/devices/iio:deviceX/in_angl1_label
What:		/sys/bus/iio/devices/iio:deviceX/in_angl2_label
KernelVersion:	5.12
Contact:	linux-iio@vger.kernel.org
Description:
		Optional symbolic label to a device channel.


Am i right?

> 
> 
> 
> > 
> > Thanks,
> > Srinivas
> > 
> > > 
> > > 
> > >   
> > > > Ideally, one iio device here is much easy to manage as other HID
> > > > sensors. If we can add something other that "x", "y" and "z"
> > > > component.  
> > > 
> > > Agreed, using axes makes no real sense here and extended_name is
> > > just a mess from ABI point of view.  Trying to solve this was the
> > > reason we added the _label interface.
> > > 
> > > Jonathan
> > > 
> > >   
> > > > Thanks,
> > > > Srinivas
> > > >   
> > > > > Thanks,
> > > > > Srinivas
> > > > > 
> > > > >     
> > > > > > Thanks,
> > > > > > 
> > > > > > Jonathan
> > > > > >     
> > > > > > > Signed-off-by: Ye Xiang <xiang.ye@intel.com>
> > > > > > > ---
> > > > > > >  .../hid-sensors/hid-sensor-attributes.c       |   2 +
> > > > > > >  drivers/iio/position/Kconfig                  |  16 +
> > > > > > >  drivers/iio/position/Makefile                 |   3 +
> > > > > > >  .../iio/position/hid-sensor-custom-hinge.c    | 412
> > > > > > > ++++++++++++++++++    
> > > > > > 
> > > > > > Given it's custom probably needs a more specific name.  I guess
> > > > > > hid-sensor-custom-intel-hinge.c might be safe?
> > > > > > 
> > > > > > Same for other places we need names in here.
> > > > > >     
> > > > > > >  4 files changed, 433 insertions(+)
> > > > > > >  create mode 100644 drivers/iio/position/hid-sensor-custom-
> > > > > > > hinge.c
> > > > > > > 
> > > > > > > diff --git a/drivers/iio/common/hid-sensors/hid-sensor-
> > > > > > > attributes.c 
> > > > > > > b/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> > > > > > > index 442ff787f7af..5b822a4298a0 100644
> > > > > > > --- a/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> > > > > > > +++ b/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> > > > > > > @@ -71,6 +71,8 @@ static struct {
> > > > > > >  	{HID_USAGE_SENSOR_TEMPERATURE,
> > > > > > > HID_USAGE_SENSOR_UNITS_DEGREES,
> > > > > > > 1000, 0},
> > > > > > >  
> > > > > > >  	{HID_USAGE_SENSOR_HUMIDITY, 0, 1000, 0},
> > > > > > > +	{HID_USAGE_SENSOR_HINGE, 0, 0, 17453293},
> > > > > > > +	{HID_USAGE_SENSOR_HINGE,
> > > > > > > HID_USAGE_SENSOR_UNITS_DEGREES, 0,
> > > > > > > 17453293},
> > > > > > >  };
> > > > > > >  
> > > > > > >  static void simple_div(int dividend, int divisor, int
> > > > > > > *whole,
> > > > > > > diff --git a/drivers/iio/position/Kconfig
> > > > > > > b/drivers/iio/position/Kconfig
> > > > > > > index eda67f008c5b..0346f6f2b422 100644
> > > > > > > --- a/drivers/iio/position/Kconfig
> > > > > > > +++ b/drivers/iio/position/Kconfig
> > > > > > > @@ -16,4 +16,20 @@ config IQS624_POS
> > > > > > >  	  To compile this driver as a module, choose M here:
> > > > > > > the module
> > > > > > >  	  will be called iqs624-pos.
> > > > > > >  
> > > > > > > +config HID_SENSOR_CUSTOM_HINGE
> > > > > > > +	depends on HID_SENSOR_HUB
> > > > > > > +	select IIO_BUFFER
> > > > > > > +	select IIO_TRIGGERED_BUFFER
> > > > > > > +	select HID_SENSOR_IIO_COMMON
> > > > > > > +	select HID_SENSOR_IIO_TRIGGER
> > > > > > > +	tristate "HID Hinge"
> > > > > > > +	help
> > > > > > > +	  This sensor present three angles, hinge angel, screen
> > > > > > > angles
> > > > > > > +	  and keyboard angle respect to horizon (ground).
> > > > > > > +	  Say yes here to build support for the HID SENSOR
> > > > > > > CUSTOM
> > > > > > > +	  HINGE.    
> > > > > > 
> > > > > > Capitalization is a bit odd looking. I'd drop it.
> > > > > >     
> > > > > > > +
> > > > > > > +	  To compile this driver as a module, choose M here:
> > > > > > > the
> > > > > > > +	  module will be called hid-sensor-custom-hinge.
> > > > > > > +
> > > > > > >  endmenu
> > > > > > > diff --git a/drivers/iio/position/Makefile
> > > > > > > b/drivers/iio/position/Makefile
> > > > > > > index 3cbe7a734352..7a6225977a01 100644
> > > > > > > --- a/drivers/iio/position/Makefile
> > > > > > > +++ b/drivers/iio/position/Makefile
> > > > > > > @@ -5,3 +5,6 @@
> > > > > > >  # When adding new entries keep the list in alphabetical
> > > > > > > order
> > > > > > >  
> > > > > > >  obj-$(CONFIG_IQS624_POS)	+= iqs624-pos.o
> > > > > > > +
> > > > > > > +obj-$(CONFIG_HID_SENSOR_CUSTOM_HINGE) += hid-sensor-custom-
> > > > > > > hinge.o    
> > > > > > 
> > > > > > Alphabetical order preferred.
> > > > > >     
> > > > > > > +ccflags-y	+= -I$(srctree)/drivers/iio/common/hid-
> > > > > > > sensors    
> > > > > > 
> > > > > > Why?
> > > > > >     
> > > > > > > diff --git a/drivers/iio/position/hid-sensor-custom-hinge.c
> > > > > > > b/drivers/iio/position/hid-sensor-custom-hinge.c
> > > > > > > new file mode 100644
> > > > > > > index 000000000000..a91b333f36fa
> > > > > > > --- /dev/null
> > > > > > > +++ b/drivers/iio/position/hid-sensor-custom-hinge.c
> > > > > > > @@ -0,0 +1,412 @@
> > > > > > > +// SPDX-License-Identifier: GPL-2.0-only
> > > > > > > +/*
> > > > > > > + * HID Sensors Driver
> > > > > > > + * Copyright (c) 2020, Intel Corporation.
> > > > > > > + */
> > > > > > > +#include <linux/hid-sensor-hub.h>
> > > > > > > +#include <linux/iio/buffer.h>
> > > > > > > +#include <linux/iio/iio.h>
> > > > > > > +#include <linux/platform_device.h>
> > > > > > > +
> > > > > > > +#include "hid-sensor-trigger.h"
> > > > > > > +
> > > > > > > +/* Channel definitions */
> > > > > > > +static const struct iio_chan_spec hinge_channels[] = {
> > > > > > > +	{ .type = IIO_ANGL,
> > > > > > > +	  .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> > > > > > > +	  .info_mask_shared_by_type =
> > > > > > > +		  BIT(IIO_CHAN_INFO_OFFSET) |
> > > > > > > BIT(IIO_CHAN_INFO_SCALE)
> > > > > > > +		  BIT(IIO_CHAN_INFO_SAMP_FREQ) |
> > > > > > > BIT(IIO_CHAN_INFO_HYSTERESIS),
> > > > > > > +	  .scan_type.realbits = 16,
> > > > > > > +	  .scan_type.storagebits = 32,    
> > > > > > 
> > > > > > It a bit odd to see a single channel that is 16 bits inside a
> > > > > > 32
> > > > > > bit
> > > > > > with
> > > > > > no shift or similar.  Why not just pack it into 16 bits?
> > > > > >     
> > > > > > > +	  .scan_type.sign = 's',
> > > > > > > +	  .scan_index = 0 },
> > > > > > > +
> > > > > > > +	IIO_CHAN_SOFT_TIMESTAMP(1)
> > > > > > > +};
> > > > > > > +
> > > > > > > +struct hinge_state {
> > > > > > > +	struct iio_dev *indio_dev;
> > > > > > > +	struct hid_sensor_hub_attribute_info hinge;
> > > > > > > +	/* Reserve for 1 channel + pading + timestamp */
> > > > > > > +	u32 hinge_val[1 + 3];    
> > > > > > 
> > > > > > __aligned(8)
> > > > > > 
> > > > > > see below for requirements on this.
> > > > > > Perhaps better to use
> > > > > > 
> > > > > > 	struct hinge_scan {
> > > > > > 		u32 val;
> > > > > > 		s64 timestamp __aligned(8); // Note this is
> > > > > > needed for
> > > > > > x86_32
> > > > > > 	} scan;
> > > > > >     
> > > > > > > +	int scale_pre_decml;
> > > > > > > +	int scale_post_decml;
> > > > > > > +	int scale_precision;
> > > > > > > +	int value_offset;
> > > > > > > +	int64_t timestamp;
> > > > > > > +	u32 hinge_address;
> > > > > > > +};
> > > > > > > +
> > > > > > > +#define IIO_DEV_NUM 3    
> > > > > > 
> > > > > > That needs a prefix to make it clear it's not a generic
> > > > > > constant
> > > > > > but is specific to this driver.
> > > > > >     
> > > > > > > +
> > > > > > > +struct hinge_group {
> > > > > > > +	struct hinge_state *hg_states[IIO_DEV_NUM];
> > > > > > > +	struct hid_sensor_hub_callbacks callbacks;
> > > > > > > +	struct hid_sensor_common common_attributes;
> > > > > > > +};
> > > > > > > +
> > > > > > > +static struct hinge_group *hg_group;    
> > > > > > 
> > > > > > We shouldn't see globals like this. Please figure out how to
> > > > > > avoid
> > > > > > it.
> > > > > >     
> > > > > > > +
> > > > > > > +/* Channel read_raw handler */
> > > > > > > +static int hinge_read_raw(struct iio_dev *indio_dev,
> > > > > > > +			  struct iio_chan_spec const *chan, int
> > > > > > > *val,
> > > > > > > int *val2,
> > > > > > > +			  long mask)
> > > > > > > +{
> > > > > > > +	struct hinge_state *hg_state = iio_priv(indio_dev);
> > > > > > > +	struct hid_sensor_hub_device *hsdev;
> > > > > > > +	int report_id = -1;
> > > > > > > +	int ret_type;
> > > > > > > +	s32 min;
> > > > > > > +
> > > > > > > +	hsdev = hg_group->common_attributes.hsdev;
> > > > > > > +
> > > > > > > +	*val = 0;
> > > > > > > +	*val2 = 0;
> > > > > > > +	switch (mask) {
> > > > > > > +	case IIO_CHAN_INFO_RAW:
> > > > > > > +		hid_sensor_power_state(&hg_group-  
> > > > > > > >common_attributes,  
> > > > > > > true);
> > > > > > > +		report_id = hg_state->hinge.report_id;
> > > > > > > +		min = hg_state->hinge.logical_minimum;
> > > > > > > +		if (report_id < 0) {
> > > > > > > +			*val = 0;
> > > > > > > +			hid_sensor_power_state(&hg_group-    
> > > > > > > > common_attributes,    
> > > > > > > +					       false);
> > > > > > > +			return -EINVAL;
> > > > > > > +		}
> > > > > > > +
> > > > > > > +		*val = sensor_hub_input_attr_get_raw_value(
> > > > > > > +			hg_group->common_attributes.hsdev,
> > > > > > > hsdev-    
> > > > > > > > usage,    
> > > > > > > +			hg_state->hinge_address, report_id,
> > > > > > > SENSOR_HUB_SYNC,
> > > > > > > +			min < 0);
> > > > > > > +
> > > > > > > +		hid_sensor_power_state(&hg_group-  
> > > > > > > >common_attributes,  
> > > > > > > false);
> > > > > > > +		ret_type = IIO_VAL_INT;
> > > > > > > +		break;
> > > > > > > +	case IIO_CHAN_INFO_SCALE:
> > > > > > > +		*val = hg_state->scale_pre_decml;
> > > > > > > +		*val2 = hg_state->scale_post_decml;
> > > > > > > +		ret_type = hg_state->scale_precision;
> > > > > > > +		break;
> > > > > > > +	case IIO_CHAN_INFO_OFFSET:
> > > > > > > +		*val = hg_state->value_offset;
> > > > > > > +		ret_type = IIO_VAL_INT;
> > > > > > > +		break;
> > > > > > > +	case IIO_CHAN_INFO_SAMP_FREQ:
> > > > > > > +		ret_type = hid_sensor_read_samp_freq_value(
> > > > > > > +			&hg_group->common_attributes, val,
> > > > > > > val2);
> > > > > > > +		break;
> > > > > > > +	case IIO_CHAN_INFO_HYSTERESIS:
> > > > > > > +		ret_type = hid_sensor_read_raw_hyst_value(
> > > > > > > +			&hg_group->common_attributes, val,
> > > > > > > val2);
> > > > > > > +		break;
> > > > > > > +	default:
> > > > > > > +		ret_type = -EINVAL;
> > > > > > > +		break;
> > > > > > > +	}
> > > > > > > +
> > > > > > > +	return ret_type;
> > > > > > > +}
> > > > > > > +
> > > > > > > +/* Channel write_raw handler */
> > > > > > > +static int hinge_write_raw(struct iio_dev *indio_dev,
> > > > > > > +			   struct iio_chan_spec const *chan,
> > > > > > > int val,
> > > > > > > int val2,
> > > > > > > +			   long mask)
> > > > > > > +{
> > > > > > > +	int ret;
> > > > > > > +
> > > > > > > +	switch (mask) {
> > > > > > > +	case IIO_CHAN_INFO_SAMP_FREQ:
> > > > > > > +		ret = hid_sensor_write_samp_freq_value(
> > > > > > > +			&hg_group->common_attributes, val,
> > > > > > > val2);
> > > > > > > +		break;
> > > > > > > +	case IIO_CHAN_INFO_HYSTERESIS:
> > > > > > > +		ret = hid_sensor_write_raw_hyst_value(
> > > > > > > +			&hg_group->common_attributes, val,
> > > > > > > val2);
> > > > > > > +
> > > > > > > +		break;
> > > > > > > +	default:
> > > > > > > +		ret = -EINVAL;
> > > > > > > +	}
> > > > > > > +
> > > > > > > +	return ret;
> > > > > > > +}
> > > > > > > +
> > > > > > > +static const struct iio_info hinge_info = {
> > > > > > > +	.read_raw = &hinge_read_raw,
> > > > > > > +	.write_raw = &hinge_write_raw,
> > > > > > > +};
> > > > > > > +
> > > > > > > +/*
> > > > > > > + * Function to push data to buffer;
> > > > > > > + * wrapper added for symmetry with other hid-sensor drivers
> > > > > > > + */
> > > > > > > +static void hid_sensor_push_data(struct iio_dev *indio_dev,
> > > > > > > void
> > > > > > > *data, int len,    
> > > > > > 
> > > > > > This doesn't seem to be generic, so don't name it as such.
> > > > > >     
> > > > > > > +				 int64_t timestamp)
> > > > > > > +{
> > > > > > > +	iio_push_to_buffers_with_timestamp(indio_dev, data,
> > > > > > > timestamp);    
> > > > > > I hope that data buffer obeys the various rules needed by (and
> > > > > > admittedly
> > > > > > not that well documented) iio_push_to_buffers_with_timestamp()
> > > > > > 
> > > > > > 1. Needs to be 8 byte aligned.
> > > > > > 2. Needs to have space for an aligned 8 byte timestamp at the
> > > > > > end.
> > > > > >     
> > > > > > > +}
> > > > > > > +
> > > > > > > +/*
> > > > > > > + * Callback handler to send event after all samples are
> > > > > > > received
> > > > > > > + * and captured.
> > > > > > > + */
> > > > > > > +static int hinge_proc_event(struct hid_sensor_hub_device
> > > > > > > *hsdev,
> > > > > > > +			    unsigned int usage_id, void *priv)
> > > > > > > +{
> > > > > > > +	int i;
> > > > > > > +
> > > > > > > +	for (i = 0; i < IIO_DEV_NUM; ++i) {    
> > > > > > If we push for all sensors together, better to have
> > > > > > this as a single iio_device with 3 channels.
> > > > > > 
> > > > > > Use the channel labels (just added to IIO) to identify which is
> > > > > > which.
> > > > > >     
> > > > > > > +		struct hinge_state *hg_state;
> > > > > > > +		struct iio_dev *indio_dev;
> > > > > > > +
> > > > > > > +		hg_state = hg_group->hg_states[i];
> > > > > > > +		indio_dev = hg_state->indio_dev;
> > > > > > > +
> > > > > > > +		dev_dbg(&indio_dev->dev, "%s timestamp:%llu
> > > > > > > scan_bytes:%d\n",
> > > > > > > +			__func__, hg_state->timestamp,
> > > > > > > indio_dev-    
> > > > > > > > scan_bytes);    
> > > > > > > +
> > > > > > > +		if (!hg_state->timestamp)
> > > > > > > +			hg_state->timestamp =
> > > > > > > iio_get_time_ns(indio_dev);
> > > > > > > +
> > > > > > > +		hid_sensor_push_data(indio_dev, hg_state-  
> > > > > > > >hinge_val,  
> > > > > > > +				     sizeof(hg_state-  
> > > > > > > >hinge_val),  
> > > > > > > +				     hg_state->timestamp);
> > > > > > > +
> > > > > > > +		hg_state->timestamp = 0;
> > > > > > > +	}
> > > > > > > +
> > > > > > > +	return 0;
> > > > > > > +}
> > > > > > > +
> > > > > > > +/* Capture samples in local storage */
> > > > > > > +static int hinge_capture_sample(struct hid_sensor_hub_device
> > > > > > > *hsdev,
> > > > > > > +				unsigned int usage_id, size_t
> > > > > > > raw_len,
> > > > > > > +				char *raw_data, void *priv)
> > > > > > > +{
> > > > > > > +	struct hinge_state *hg_state;
> > > > > > > +	int offset;
> > > > > > > +	int ret = -EINVAL;
> > > > > > > +	int i;
> > > > > > > +
> > > > > > > +	if (usage_id == HID_USAGE_SENSOR_TIME_TIMESTAMP) {
> > > > > > > +		for (i = 0; i < IIO_DEV_NUM; i++)
> > > > > > > +			hg_group->hg_states[i]->timestamp =    
> > > > > > 
> > > > > > This rather implies all the data is captured together... If so
> > > > > > single
> > > > > > iio_device may make more sense.
> > > > > >     
> > > > > > > +				hid_sensor_convert_timestamp(
> > > > > > > +					&hg_group-  
> > > > > > > >common_attributes,  
> > > > > > > +					*(int64_t *)raw_data);
> > > > > > > +		return 0;
> > > > > > > +	}
> > > > > > > +
> > > > > > > +	switch (usage_id) {
> > > > > > > +	case HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_1:
> > > > > > > +	case HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_2:
> > > > > > > +	case HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_3:
> > > > > > > +		offset = usage_id -
> > > > > > > HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_1;
> > > > > > > +		hg_state = hg_group->hg_states[offset];
> > > > > > > +		hg_state->hinge_val[0] = *(u32 *)raw_data;
> > > > > > > +		ret = 0;    
> > > > > > 
> > > > > > 		return 0;
> > > > > >     
> > > > > > > +		break;
> > > > > > > +	default:    
> > > > > > 		return -EINVAL;    
> > > > > > > +		break;
> > > > > > > +	}
> > > > > > > +
> > > > > > > +	return ret;
> > > > > > > +}
> > > > > > > +
> > > > > > > +/* Parse report which is specific to an usage id */
> > > > > > > +static int hinge_parse_report(struct platform_device *pdev,
> > > > > > > +			      struct hid_sensor_hub_device
> > > > > > > *hsdev,
> > > > > > > +			      unsigned int usage_id, unsigned
> > > > > > > int
> > > > > > > attr_usage_id,
> > > > > > > +			      struct hinge_state *st)
> > > > > > > +{
> > > > > > > +	int ret;
> > > > > > > +
> > > > > > > +	ret = sensor_hub_input_get_attribute_info(
> > > > > > > +		hsdev, HID_INPUT_REPORT, usage_id,
> > > > > > > attr_usage_id, &st-    
> > > > > > > > hinge);    
> > > > > > > +	if (ret < 0)
> > > > > > > +		return ret;
> > > > > > > +
> > > > > > > +	st->hinge_address = attr_usage_id;
> > > > > > > +	st->scale_precision =
> > > > > > > +		hid_sensor_format_scale(HID_USAGE_SENSOR_HINGE,
> > > > > > > &st-    
> > > > > > > > hinge,    
> > > > > > > +					&st->scale_pre_decml,
> > > > > > > +					&st->scale_post_decml);
> > > > > > > +
> > > > > > > +	/* Set Sensitivity field ids, when there is no
> > > > > > > individual
> > > > > > > modifier */
> > > > > > > +	if (hg_group->common_attributes.sensitivity.index < 0)
> > > > > > > {
> > > > > > > +		sensor_hub_input_get_attribute_info(
> > > > > > > +			hsdev, HID_FEATURE_REPORT, usage_id,
> > > > > > > +			HID_USAGE_SENSOR_DATA_MOD_CHANGE_SENSIT
> > > > > > > IVITY_AB
> > > > > > > S |
> > > > > > > +				HID_USAGE_SENSOR_DATA_FIELD_CUS
> > > > > > > TOM_VALU
> > > > > > > E_1,
> > > > > > > +			&hg_group-  
> > > > > > > >common_attributes.sensitivity);  
> > > > > > > +		dev_dbg(&pdev->dev, "Sensitivity index:report
> > > > > > > %d:%d\n",
> > > > > > > +			hg_group-  
> > > > > > > >common_attributes.sensitivity.index,  
> > > > > > > +			hg_group-    
> > > > > > > > common_attributes.sensitivity.report_id);    
> > > > > > > +	}
> > > > > > > +
> > > > > > > +	return ret;
> > > > > > > +}
> > > > > > > +
> > > > > > > +/* Function to initialize the processing for usage id */
> > > > > > > +static int hinge_add_iio_device(struct platform_device
> > > > > > > *pdev,
> > > > > > > int
> > > > > > > index,
> > > > > > > +				const char *name, struct
> > > > > > > hinge_state
> > > > > > > **st)
> > > > > > > +{
> > > > > > > +	struct hid_sensor_hub_device *hsdev = pdev-  
> > > > > > > >dev.platform_data;  
> > > > > > > +	struct hinge_state *hg_state;
> > > > > > > +	struct iio_dev *indio_dev;
> > > > > > > +	int ret;
> > > > > > > +
> > > > > > > +	indio_dev =
> > > > > > > +		devm_iio_device_alloc(&pdev->dev, sizeof(struct
> > > > > > > hinge_state));    
> > > > > > 
> > > > > > sizeof (*hg_state) preferred.
> > > > > >     
> > > > > > > +	if (indio_dev == NULL)
> > > > > > > +		return -ENOMEM;
> > > > > > > +
> > > > > > > +	hg_state = iio_priv(indio_dev);
> > > > > > > +	hg_state->indio_dev = indio_dev;
> > > > > > > +
> > > > > > > +	indio_dev->num_channels = ARRAY_SIZE(hinge_channels);
> > > > > > > +	indio_dev->channels =
> > > > > > > +		kmemdup(hinge_channels, sizeof(hinge_channels),
> > > > > > > GFP_KERNEL);    
> > > > > > 
> > > > > > I don't immediately see anything that is modifying channels. As
> > > > > > such
> > > > > > you
> > > > > > should be able have it shared by all the instances.
> > > > > >     
> > > > > > > +	if (!indio_dev->channels)
> > > > > > > +		return -ENOMEM;
> > > > > > > +
> > > > > > > +	ret = hinge_parse_report(
> > > > > > > +		pdev, hsdev, hsdev->usage,
> > > > > > > +		HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_1 +
> > > > > > > index,
> > > > > > > hg_state);
> > > > > > > +	if (ret) {
> > > > > > > +		dev_err(&pdev->dev, "failed to setup
> > > > > > > attributes\n");
> > > > > > > +		goto error_free_dev_mem;
> > > > > > > +	}
> > > > > > > +
> > > > > > > +	indio_dev->dev.parent = &pdev->dev;
> > > > > > > +	indio_dev->info = &hinge_info;
> > > > > > > +	indio_dev->name = name;
> > > > > > > +	indio_dev->modes = INDIO_DIRECT_MODE;
> > > > > > > +
> > > > > > > +	ret = hid_sensor_setup_trigger(indio_dev, name,
> > > > > > > +				       &hg_group-  
> > > > > > > >common_attributes);  
> > > > > > > +	if (ret < 0) {
> > > > > > > +		dev_err(&pdev->dev, "trigger setup failed\n");
> > > > > > > +		goto error_free_dev_mem;
> > > > > > > +	}
> > > > > > > +
> > > > > > > +	ret = iio_device_register(indio_dev);
> > > > > > > +	if (ret) {
> > > > > > > +		dev_err(&pdev->dev, "device register
> > > > > > > failed\n");
> > > > > > > +		goto error_remove_trigger;
> > > > > > > +	}
> > > > > > > +
> > > > > > > +	*st = hg_state;
> > > > > > > +
> > > > > > > +	return ret;
> > > > > > > +
> > > > > > > +error_remove_trigger:
> > > > > > > +	hid_sensor_remove_trigger(indio_dev, &hg_group-    
> > > > > > > > common_attributes);    
> > > > > > > +error_free_dev_mem:
> > > > > > > +	kfree(indio_dev->channels);
> > > > > > > +	return ret;
> > > > > > > +}
> > > > > > > +
> > > > > > > +/* Function to deinitialize the processing for usage id */
> > > > > > > +static int hinge_remove_iio_device(struct platform_device
> > > > > > > *pdev,
> > > > > > > int index)
> > > > > > > +{
> > > > > > > +	struct hinge_state *hg_state = hg_group-  
> > > > > > > >hg_states[index];  
> > > > > > > +	struct iio_dev *indio_dev = hg_state->indio_dev;
> > > > > > > +
> > > > > > > +	iio_device_unregister(indio_dev);
> > > > > > > +	hid_sensor_remove_trigger(indio_dev, &hg_group-    
> > > > > > > > common_attributes);    
> > > > > > > +	kfree(indio_dev->channels);
> > > > > > > +
> > > > > > > +	return 0;
> > > > > > > +}
> > > > > > > +
> > > > > > > +static int hid_hinge_probe(struct platform_device *pdev)
> > > > > > > +{
> > > > > > > +	struct hinge_state *hg_state;
> > > > > > > +	struct hid_sensor_hub_device *hsdev = pdev-  
> > > > > > > >dev.platform_data;  
> > > > > > > +	static const char *const names[] = { "hinge", "screen",
> > > > > > > "keyboard" };
> > > > > > > +	int ret;
> > > > > > > +	int i;
> > > > > > > +
> > > > > > > +	hg_group = devm_kzalloc(&pdev->dev, sizeof(struct
> > > > > > > hinge_group),
> > > > > > > +				GFP_KERNEL);    
> > > > > > 
> > > > > > As mentioned above, I'd really not expect to see a global like
> > > > > > this.
> > > > > > Technically nothing stops there being more than one instance of
> > > > > > this
> > > > > > device on a platform (even if that would be a bit odd) + it's
> > > > > > almost
> > > > > > always cleaner to not use a global in the first place.
> > > > > >     
> > > > > > > +	if (!hg_group)
> > > > > > > +		return -ENOMEM;
> > > > > > > +
> > > > > > > +	hg_group->common_attributes.hsdev = hsdev;
> > > > > > > +	hg_group->common_attributes.pdev = pdev;
> > > > > > > +
> > > > > > > +	ret = hid_sensor_parse_common_attributes(hsdev, hsdev-  
> > > > > > > >usage,  
> > > > > > > +						 &hg_group-    
> > > > > > > > common_attributes);    
> > > > > > > +	if (ret) {
> > > > > > > +		dev_err(&pdev->dev, "failed to setup common
> > > > > > > attributes\n");
> > > > > > > +		return ret;
> > > > > > > +	}
> > > > > > > +
> > > > > > > +	atomic_set(&hg_group->common_attributes.data_ready, 0);
> > > > > > > +	for (i = 0; i < IIO_DEV_NUM; i++) {
> > > > > > > +		ret = hinge_add_iio_device(pdev, i, names[i],
> > > > > > > &hg_state);
> > > > > > > +		if (ret)
> > > > > > > +			goto err_probe;
> > > > > > > +
> > > > > > > +		hg_group->hg_states[i] = hg_state;
> > > > > > > +	}
> > > > > > > +
> > > > > > > +	/* use the first iio device to do the PM */
> > > > > > > +	platform_set_drvdata(pdev, hg_group->hg_states[0]-  
> > > > > > > >indio_dev);  
> > > > > > > +
> > > > > > > +	hg_group->callbacks.send_event = hinge_proc_event;
> > > > > > > +	hg_group->callbacks.capture_sample =
> > > > > > > hinge_capture_sample;
> > > > > > > +	hg_group->callbacks.pdev = pdev;
> > > > > > > +	ret = sensor_hub_register_callback(hsdev, hsdev->usage,
> > > > > > > +					   &hg_group-  
> > > > > > > >callbacks);  
> > > > > > > +	if (ret < 0)
> > > > > > > +		dev_err(&pdev->dev, "callback reg failed\n");
> > > > > > > +
> > > > > > > +	return ret;
> > > > > > > +
> > > > > > > +err_probe:
> > > > > > > +	for (i--; i >= 0; i--)
> > > > > > > +		hinge_remove_iio_device(pdev, i);
> > > > > > > +
> > > > > > > +	return ret;
> > > > > > > +}
> > > > > > > +
> > > > > > > +/* Function to deinitialize the processing for usage id */
> > > > > > > +static int hid_hinge_remove(struct platform_device *pdev)
> > > > > > > +{
> > > > > > > +	struct hid_sensor_hub_device *hsdev = pdev-  
> > > > > > > >dev.platform_data;  
> > > > > > > +	int i;
> > > > > > > +
> > > > > > > +	sensor_hub_remove_callback(hsdev, hsdev->usage);
> > > > > > > +
> > > > > > > +	for (i = 0; i < IIO_DEV_NUM; i++)
> > > > > > > +		hinge_remove_iio_device(pdev, i);
> > > > > > > +
> > > > > > > +	return 0;
> > > > > > > +}
> > > > > > > +
> > > > > > > +static const struct platform_device_id hid_hinge_ids[] = {
> > > > > > > +	{
> > > > > > > +		/* Format: HID-SENSOR-INT-
> > > > > > > usage_id_in_hex_lowercase */
> > > > > > > +		.name = "HID-SENSOR-INT-020b",
> > > > > > > +	},
> > > > > > > +	{ /* sentinel */ }
> > > > > > > +};
> > > > > > > +MODULE_DEVICE_TABLE(platform, hid_hinge_ids);
> > > > > > > +
> > > > > > > +static struct platform_driver hid_hinge_platform_driver = {
> > > > > > > +	.id_table = hid_hinge_ids,
> > > > > > > +	.driver = {
> > > > > > > +		.name	= KBUILD_MODNAME,
> > > > > > > +		.pm	= &hid_sensor_pm_ops,
> > > > > > > +	},
> > > > > > > +	.probe		= hid_hinge_probe,
> > > > > > > +	.remove		= hid_hinge_remove,
> > > > > > > +};
> > > > > > > +module_platform_driver(hid_hinge_platform_driver);
> > > > > > > +
> > > > > > > +MODULE_DESCRIPTION("HID Sensor Custom Hinge");
> > > > > > > +MODULE_AUTHOR("Ye Xiang <xiang.ye@intel.com>");
> > > > > > > +MODULE_LICENSE("GPL");    
>

Ye Xiang Nov. 24, 2020, 6:43 a.m. UTC | #8

On Sat, Nov 21, 2020 at 05:56:29PM +0000, Jonathan Cameron wrote:
> On Thu, 19 Nov 2020 18:03:31 +0800
> Ye Xiang <xiang.ye@intel.com> wrote:
> 
> > The Hinge sensor is a common custom sensor on laptops. It calculates
> > the angle between the lid (screen) and the base (keyboard). In addition,
> > it also exposes screen and the keyboard angels with respect to the
> > ground. Applications can easily get laptop's status in space through
> > this sensor, in order to display appropriate user interface.
> 
> I'm a little unclear on why the 3 axes aren't treated as a single sensor.
> You seem to always grab the 3 together or am I missing something?
> 
> That will greatly simplify things and get rid of the need to have
> a shared trigger with the problems that causes in the previous
> patch.
> 
> Thanks,
> 
> Jonathan
> 
> > 
> > Signed-off-by: Ye Xiang <xiang.ye@intel.com>
> > ---
> >  .../hid-sensors/hid-sensor-attributes.c       |   2 +
> >  drivers/iio/position/Kconfig                  |  16 +
> >  drivers/iio/position/Makefile                 |   3 +
> >  .../iio/position/hid-sensor-custom-hinge.c    | 412 ++++++++++++++++++
> 
> Given it's custom probably needs a more specific name.  I guess
> hid-sensor-custom-intel-hinge.c might be safe?
> 
> Same for other places we need names in here.
agree, will change the name to hid-sensor-custom-intel-hinge.c
> 
> >  4 files changed, 433 insertions(+)
> >  create mode 100644 drivers/iio/position/hid-sensor-custom-hinge.c
> > 
> > diff --git a/drivers/iio/common/hid-sensors/hid-sensor-attributes.c b/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> > index 442ff787f7af..5b822a4298a0 100644
> > --- a/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> > +++ b/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> > @@ -71,6 +71,8 @@ static struct {
> >  	{HID_USAGE_SENSOR_TEMPERATURE, HID_USAGE_SENSOR_UNITS_DEGREES, 1000, 0},
> >  
> >  	{HID_USAGE_SENSOR_HUMIDITY, 0, 1000, 0},
> > +	{HID_USAGE_SENSOR_HINGE, 0, 0, 17453293},
> > +	{HID_USAGE_SENSOR_HINGE, HID_USAGE_SENSOR_UNITS_DEGREES, 0, 17453293},
> >  };
> >  
> >  static void simple_div(int dividend, int divisor, int *whole,
> > diff --git a/drivers/iio/position/Kconfig b/drivers/iio/position/Kconfig
> > index eda67f008c5b..0346f6f2b422 100644
> > --- a/drivers/iio/position/Kconfig
> > +++ b/drivers/iio/position/Kconfig
> > @@ -16,4 +16,20 @@ config IQS624_POS
> >  	  To compile this driver as a module, choose M here: the module
> >  	  will be called iqs624-pos.
> >  
> > +config HID_SENSOR_CUSTOM_HINGE
> > +	depends on HID_SENSOR_HUB
> > +	select IIO_BUFFER
> > +	select IIO_TRIGGERED_BUFFER
> > +	select HID_SENSOR_IIO_COMMON
> > +	select HID_SENSOR_IIO_TRIGGER
> > +	tristate "HID Hinge"
> > +	help
> > +	  This sensor present three angles, hinge angel, screen angles
> > +	  and keyboard angle respect to horizon (ground).
> > +	  Say yes here to build support for the HID SENSOR CUSTOM
> > +	  HINGE.
> 
> Capitalization is a bit odd looking. I'd drop it.
ok, will use lowercase.
> 
> > +
> > +	  To compile this driver as a module, choose M here: the
> > +	  module will be called hid-sensor-custom-hinge.
> > +
> >  endmenu
> > diff --git a/drivers/iio/position/Makefile b/drivers/iio/position/Makefile
> > index 3cbe7a734352..7a6225977a01 100644
> > --- a/drivers/iio/position/Makefile
> > +++ b/drivers/iio/position/Makefile
> > @@ -5,3 +5,6 @@
> >  # When adding new entries keep the list in alphabetical order
> >  
> >  obj-$(CONFIG_IQS624_POS)	+= iqs624-pos.o
> > +
> > +obj-$(CONFIG_HID_SENSOR_CUSTOM_HINGE) += hid-sensor-custom-hinge.o
> 
> Alphabetical order preferred.
> 
> > +ccflags-y	+= -I$(srctree)/drivers/iio/common/hid-sensors
> 
> Why?
hinge driver need to include #include "hid-sensor-trigger.h", if not using this cflag-y
it should be #include "../common/hid-sensors/hid-sensor-trigger.h"

> 
> > diff --git a/drivers/iio/position/hid-sensor-custom-hinge.c b/drivers/iio/position/hid-sensor-custom-hinge.c
> > new file mode 100644
> > index 000000000000..a91b333f36fa
> > --- /dev/null
> > +++ b/drivers/iio/position/hid-sensor-custom-hinge.c
> > @@ -0,0 +1,412 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +/*
> > + * HID Sensors Driver
> > + * Copyright (c) 2020, Intel Corporation.
> > + */
> > +#include <linux/hid-sensor-hub.h>
> > +#include <linux/iio/buffer.h>
> > +#include <linux/iio/iio.h>
> > +#include <linux/platform_device.h>
> > +
> > +#include "hid-sensor-trigger.h"
> > +
> > +/* Channel definitions */
> > +static const struct iio_chan_spec hinge_channels[] = {
> > +	{ .type = IIO_ANGL,
> > +	  .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> > +	  .info_mask_shared_by_type =
> > +		  BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_SCALE) |
> > +		  BIT(IIO_CHAN_INFO_SAMP_FREQ) | BIT(IIO_CHAN_INFO_HYSTERESIS),
> > +	  .scan_type.realbits = 16,
> > +	  .scan_type.storagebits = 32,
> 
> It a bit odd to see a single channel that is 16 bits inside a 32 bit with
> no shift or similar.  Why not just pack it into 16 bits?
As it's said in last email, will use one iio device with three labeled channel
then will not hard code the realbits and storagebits.

> 
> > +	  .scan_type.sign = 's',
> > +	  .scan_index = 0 },
> > +
> > +	IIO_CHAN_SOFT_TIMESTAMP(1)
> > +};
> > +
> > +struct hinge_state {
> > +	struct iio_dev *indio_dev;
> > +	struct hid_sensor_hub_attribute_info hinge;
> > +	/* Reserve for 1 channel + pading + timestamp */
> > +	u32 hinge_val[1 + 3];
> 
> __aligned(8)
> 
> see below for requirements on this.
> Perhaps better to use
> 
> 	struct hinge_scan {
> 		u32 val;
> 		s64 timestamp __aligned(8); // Note this is needed for x86_32
> 	} scan;
>
This patch use hard code pading for align(8)
I think your method this is a good choice, will use it thanks.

> > +	int scale_pre_decml;
> > +	int scale_post_decml;
> > +	int scale_precision;
> > +	int value_offset;
> > +	int64_t timestamp;
> > +	u32 hinge_address;
> > +};
> > +
> > +#define IIO_DEV_NUM 3
> 
> That needs a prefix to make it clear it's not a generic constant
> but is specific to this driver.
Will use one iio device, so this macro will be abandon.

> 
> > +
> > +struct hinge_group {
> > +	struct hinge_state *hg_states[IIO_DEV_NUM];
> > +	struct hid_sensor_hub_callbacks callbacks;
> > +	struct hid_sensor_common common_attributes;
> > +};
> > +
> > +static struct hinge_group *hg_group;
> 
> We shouldn't see globals like this. Please figure out how to avoid it.
ditto
> 
> > +
> > +/* Channel read_raw handler */
> > +static int hinge_read_raw(struct iio_dev *indio_dev,
> > +			  struct iio_chan_spec const *chan, int *val, int *val2,
> > +			  long mask)
> > +{
> > +	struct hinge_state *hg_state = iio_priv(indio_dev);
> > +	struct hid_sensor_hub_device *hsdev;
> > +	int report_id = -1;
> > +	int ret_type;
> > +	s32 min;
> > +
> > +	hsdev = hg_group->common_attributes.hsdev;
> > +
> > +	*val = 0;
> > +	*val2 = 0;
> > +	switch (mask) {
> > +	case IIO_CHAN_INFO_RAW:
> > +		hid_sensor_power_state(&hg_group->common_attributes, true);
> > +		report_id = hg_state->hinge.report_id;
> > +		min = hg_state->hinge.logical_minimum;
> > +		if (report_id < 0) {
> > +			*val = 0;
> > +			hid_sensor_power_state(&hg_group->common_attributes,
> > +					       false);
> > +			return -EINVAL;
> > +		}
> > +
> > +		*val = sensor_hub_input_attr_get_raw_value(
> > +			hg_group->common_attributes.hsdev, hsdev->usage,
> > +			hg_state->hinge_address, report_id, SENSOR_HUB_SYNC,
> > +			min < 0);
> > +
> > +		hid_sensor_power_state(&hg_group->common_attributes, false);
> > +		ret_type = IIO_VAL_INT;
> > +		break;
> > +	case IIO_CHAN_INFO_SCALE:
> > +		*val = hg_state->scale_pre_decml;
> > +		*val2 = hg_state->scale_post_decml;
> > +		ret_type = hg_state->scale_precision;
> > +		break;
> > +	case IIO_CHAN_INFO_OFFSET:
> > +		*val = hg_state->value_offset;
> > +		ret_type = IIO_VAL_INT;
> > +		break;
> > +	case IIO_CHAN_INFO_SAMP_FREQ:
> > +		ret_type = hid_sensor_read_samp_freq_value(
> > +			&hg_group->common_attributes, val, val2);
> > +		break;
> > +	case IIO_CHAN_INFO_HYSTERESIS:
> > +		ret_type = hid_sensor_read_raw_hyst_value(
> > +			&hg_group->common_attributes, val, val2);
> > +		break;
> > +	default:
> > +		ret_type = -EINVAL;
> > +		break;
> > +	}
> > +
> > +	return ret_type;
> > +}
> > +
> > +/* Channel write_raw handler */
> > +static int hinge_write_raw(struct iio_dev *indio_dev,
> > +			   struct iio_chan_spec const *chan, int val, int val2,
> > +			   long mask)
> > +{
> > +	int ret;
> > +
> > +	switch (mask) {
> > +	case IIO_CHAN_INFO_SAMP_FREQ:
> > +		ret = hid_sensor_write_samp_freq_value(
> > +			&hg_group->common_attributes, val, val2);
> > +		break;
> > +	case IIO_CHAN_INFO_HYSTERESIS:
> > +		ret = hid_sensor_write_raw_hyst_value(
> > +			&hg_group->common_attributes, val, val2);
> > +
> > +		break;
> > +	default:
> > +		ret = -EINVAL;
> > +	}
> > +
> > +	return ret;
> > +}
> > +
> > +static const struct iio_info hinge_info = {
> > +	.read_raw = &hinge_read_raw,
> > +	.write_raw = &hinge_write_raw,
> > +};
> > +
> > +/*
> > + * Function to push data to buffer;
> > + * wrapper added for symmetry with other hid-sensor drivers
> > + */
> > +static void hid_sensor_push_data(struct iio_dev *indio_dev, void *data, int len,
> 
> This doesn't seem to be generic, so don't name it as such.
got it.
> 
> > +				 int64_t timestamp)
> > +{
> > +	iio_push_to_buffers_with_timestamp(indio_dev, data, timestamp);
> I hope that data buffer obeys the various rules needed by (and admittedly
> not that well documented) iio_push_to_buffers_with_timestamp()
> 
> 1. Needs to be 8 byte aligned.
> 2. Needs to have space for an aligned 8 byte timestamp at the end.
yes, it use a padding to make it align to 8byte. As is said before
, will use your recommend method instead.
> 
> > +}
> > +
> > +/*
> > + * Callback handler to send event after all samples are received
> > + * and captured.
> > + */
> > +static int hinge_proc_event(struct hid_sensor_hub_device *hsdev,
> > +			    unsigned int usage_id, void *priv)
> > +{
> > +	int i;
> > +
> > +	for (i = 0; i < IIO_DEV_NUM; ++i) {
> If we push for all sensors together, better to have
> this as a single iio_device with 3 channels.
> 
> Use the channel labels (just added to IIO) to identify which is which.
Will try to use channel labels

> 
> > +		struct hinge_state *hg_state;
> > +		struct iio_dev *indio_dev;
> > +
> > +		hg_state = hg_group->hg_states[i];
> > +		indio_dev = hg_state->indio_dev;
> > +
> > +		dev_dbg(&indio_dev->dev, "%s timestamp:%llu scan_bytes:%d\n",
> > +			__func__, hg_state->timestamp, indio_dev->scan_bytes);
> > +
> > +		if (!hg_state->timestamp)
> > +			hg_state->timestamp = iio_get_time_ns(indio_dev);
> > +
> > +		hid_sensor_push_data(indio_dev, hg_state->hinge_val,
> > +				     sizeof(hg_state->hinge_val),
> > +				     hg_state->timestamp);
> > +
> > +		hg_state->timestamp = 0;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +/* Capture samples in local storage */
> > +static int hinge_capture_sample(struct hid_sensor_hub_device *hsdev,
> > +				unsigned int usage_id, size_t raw_len,
> > +				char *raw_data, void *priv)
> > +{
> > +	struct hinge_state *hg_state;
> > +	int offset;
> > +	int ret = -EINVAL;
> > +	int i;
> > +
> > +	if (usage_id == HID_USAGE_SENSOR_TIME_TIMESTAMP) {
> > +		for (i = 0; i < IIO_DEV_NUM; i++)
> > +			hg_group->hg_states[i]->timestamp =
> 
> This rather implies all the data is captured together... If so single
> iio_device may make more sense.
will use one iio device with three channel.
> 
> > +				hid_sensor_convert_timestamp(
> > +					&hg_group->common_attributes,
> > +					*(int64_t *)raw_data);
> > +		return 0;
> > +	}
> > +
> > +	switch (usage_id) {
> > +	case HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_1:
> > +	case HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_2:
> > +	case HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_3:
> > +		offset = usage_id - HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_1;
> > +		hg_state = hg_group->hg_states[offset];
> > +		hg_state->hinge_val[0] = *(u32 *)raw_data;
> > +		ret = 0;
> 
> 		return 0;
> 
> > +		break;
> > +	default:
> 		return -EINVAL;
ok, but i think it's the same..

> > +		break;
> > +	}
> > +
> > +	return ret;
> > +}
> > +
> > +/* Parse report which is specific to an usage id */
> > +static int hinge_parse_report(struct platform_device *pdev,
> > +			      struct hid_sensor_hub_device *hsdev,
> > +			      unsigned int usage_id, unsigned int attr_usage_id,
> > +			      struct hinge_state *st)
> > +{
> > +	int ret;
> > +
> > +	ret = sensor_hub_input_get_attribute_info(
> > +		hsdev, HID_INPUT_REPORT, usage_id, attr_usage_id, &st->hinge);
> > +	if (ret < 0)
> > +		return ret;
> > +
> > +	st->hinge_address = attr_usage_id;
> > +	st->scale_precision =
> > +		hid_sensor_format_scale(HID_USAGE_SENSOR_HINGE, &st->hinge,
> > +					&st->scale_pre_decml,
> > +					&st->scale_post_decml);
> > +
> > +	/* Set Sensitivity field ids, when there is no individual modifier */
> > +	if (hg_group->common_attributes.sensitivity.index < 0) {
> > +		sensor_hub_input_get_attribute_info(
> > +			hsdev, HID_FEATURE_REPORT, usage_id,
> > +			HID_USAGE_SENSOR_DATA_MOD_CHANGE_SENSITIVITY_ABS |
> > +				HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_1,
> > +			&hg_group->common_attributes.sensitivity);
> > +		dev_dbg(&pdev->dev, "Sensitivity index:report %d:%d\n",
> > +			hg_group->common_attributes.sensitivity.index,
> > +			hg_group->common_attributes.sensitivity.report_id);
> > +	}
> > +
> > +	return ret;
> > +}
> > +
> > +/* Function to initialize the processing for usage id */
> > +static int hinge_add_iio_device(struct platform_device *pdev, int index,
> > +				const char *name, struct hinge_state **st)
> > +{
> > +	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
> > +	struct hinge_state *hg_state;
> > +	struct iio_dev *indio_dev;
> > +	int ret;
> > +
> > +	indio_dev =
> > +		devm_iio_device_alloc(&pdev->dev, sizeof(struct hinge_state));
> 
> sizeof (*hg_state) preferred.
got it.
> 
> > +	if (indio_dev == NULL)
> > +		return -ENOMEM;
> > +
> > +	hg_state = iio_priv(indio_dev);
> > +	hg_state->indio_dev = indio_dev;
> > +
> > +	indio_dev->num_channels = ARRAY_SIZE(hinge_channels);
> > +	indio_dev->channels =
> > +		kmemdup(hinge_channels, sizeof(hinge_channels), GFP_KERNEL);
> 
> I don't immediately see anything that is modifying channels. As such you
> should be able have it shared by all the instances.
will try to use one iio device.
> 
> > +	if (!indio_dev->channels)
> > +		return -ENOMEM;
> > +
> > +	ret = hinge_parse_report(
> > +		pdev, hsdev, hsdev->usage,
> > +		HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_1 + index, hg_state);
> > +	if (ret) {
> > +		dev_err(&pdev->dev, "failed to setup attributes\n");
> > +		goto error_free_dev_mem;
> > +	}
> > +
> > +	indio_dev->dev.parent = &pdev->dev;
> > +	indio_dev->info = &hinge_info;
> > +	indio_dev->name = name;
> > +	indio_dev->modes = INDIO_DIRECT_MODE;
> > +
> > +	ret = hid_sensor_setup_trigger(indio_dev, name,
> > +				       &hg_group->common_attributes);
> > +	if (ret < 0) {
> > +		dev_err(&pdev->dev, "trigger setup failed\n");
> > +		goto error_free_dev_mem;
> > +	}
> > +
> > +	ret = iio_device_register(indio_dev);
> > +	if (ret) {
> > +		dev_err(&pdev->dev, "device register failed\n");
> > +		goto error_remove_trigger;
> > +	}
> > +
> > +	*st = hg_state;
> > +
> > +	return ret;
> > +
> > +error_remove_trigger:
> > +	hid_sensor_remove_trigger(indio_dev, &hg_group->common_attributes);
> > +error_free_dev_mem:
> > +	kfree(indio_dev->channels);
> > +	return ret;
> > +}
> > +
> > +/* Function to deinitialize the processing for usage id */
> > +static int hinge_remove_iio_device(struct platform_device *pdev, int index)
> > +{
> > +	struct hinge_state *hg_state = hg_group->hg_states[index];
> > +	struct iio_dev *indio_dev = hg_state->indio_dev;
> > +
> > +	iio_device_unregister(indio_dev);
> > +	hid_sensor_remove_trigger(indio_dev, &hg_group->common_attributes);
> > +	kfree(indio_dev->channels);
> > +
> > +	return 0;
> > +}
> > +
> > +static int hid_hinge_probe(struct platform_device *pdev)
> > +{
> > +	struct hinge_state *hg_state;
> > +	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
> > +	static const char *const names[] = { "hinge", "screen", "keyboard" };
> > +	int ret;
> > +	int i;
> > +
> > +	hg_group = devm_kzalloc(&pdev->dev, sizeof(struct hinge_group),
> > +				GFP_KERNEL);
> 
> As mentioned above, I'd really not expect to see a global like this.
> Technically nothing stops there being more than one instance of this
> device on a platform (even if that would be a bit odd) + it's almost
> always cleaner to not use a global in the first place.
using one iio device can avoid using the global variable.

> 
> > +	if (!hg_group)
> > +		return -ENOMEM;
> > +
> > +	hg_group->common_attributes.hsdev = hsdev;
> > +	hg_group->common_attributes.pdev = pdev;
> > +
> > +	ret = hid_sensor_parse_common_attributes(hsdev, hsdev->usage,
> > +						 &hg_group->common_attributes);
> > +	if (ret) {
> > +		dev_err(&pdev->dev, "failed to setup common attributes\n");
> > +		return ret;
> > +	}
> > +
> > +	atomic_set(&hg_group->common_attributes.data_ready, 0);
> > +	for (i = 0; i < IIO_DEV_NUM; i++) {
> > +		ret = hinge_add_iio_device(pdev, i, names[i], &hg_state);
> > +		if (ret)
> > +			goto err_probe;
> > +
> > +		hg_group->hg_states[i] = hg_state;
> > +	}
> > +
> > +	/* use the first iio device to do the PM */
> > +	platform_set_drvdata(pdev, hg_group->hg_states[0]->indio_dev);
> > +
> > +	hg_group->callbacks.send_event = hinge_proc_event;
> > +	hg_group->callbacks.capture_sample = hinge_capture_sample;
> > +	hg_group->callbacks.pdev = pdev;
> > +	ret = sensor_hub_register_callback(hsdev, hsdev->usage,
> > +					   &hg_group->callbacks);
> > +	if (ret < 0)
> > +		dev_err(&pdev->dev, "callback reg failed\n");
> > +
> > +	return ret;
> > +
> > +err_probe:
> > +	for (i--; i >= 0; i--)
> > +		hinge_remove_iio_device(pdev, i);
> > +
> > +	return ret;
> > +}
> > +
> > +/* Function to deinitialize the processing for usage id */
> > +static int hid_hinge_remove(struct platform_device *pdev)
> > +{
> > +	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
> > +	int i;
> > +
> > +	sensor_hub_remove_callback(hsdev, hsdev->usage);
> > +
> > +	for (i = 0; i < IIO_DEV_NUM; i++)
> > +		hinge_remove_iio_device(pdev, i);
> > +
> > +	return 0;
> > +}
> > +
> > +static const struct platform_device_id hid_hinge_ids[] = {
> > +	{
> > +		/* Format: HID-SENSOR-INT-usage_id_in_hex_lowercase */
> > +		.name = "HID-SENSOR-INT-020b",
> > +	},
> > +	{ /* sentinel */ }
> > +};
> > +MODULE_DEVICE_TABLE(platform, hid_hinge_ids);
> > +
> > +static struct platform_driver hid_hinge_platform_driver = {
> > +	.id_table = hid_hinge_ids,
> > +	.driver = {
> > +		.name	= KBUILD_MODNAME,
> > +		.pm	= &hid_sensor_pm_ops,
> > +	},
> > +	.probe		= hid_hinge_probe,
> > +	.remove		= hid_hinge_remove,
> > +};
> > +module_platform_driver(hid_hinge_platform_driver);
> > +
> > +MODULE_DESCRIPTION("HID Sensor Custom Hinge");
> > +MODULE_AUTHOR("Ye Xiang <xiang.ye@intel.com>");
> > +MODULE_LICENSE("GPL");
>

Jonathan Cameron Nov. 24, 2020, 11:36 a.m. UTC | #9

On Tue, 24 Nov 2020 11:30:50 +0800
"Ye, Xiang" <xiang.ye@intel.com> wrote:

> On Sun, Nov 22, 2020 at 04:50:47PM +0000, Jonathan Cameron wrote:
> > On Sun, 22 Nov 2020 15:51:18 +0000
> > "Pandruvada, Srinivas" <srinivas.pandruvada@intel.com> wrote:
> >   
> > > On Sun, 2020-11-22 at 14:14 +0000, Jonathan Cameron wrote:  
> > > > On Sun, 22 Nov 2020 02:14:16 +0000
> > > > "Pandruvada, Srinivas" <srinivas.pandruvada@intel.com> wrote:
> > > >     
> > > > > On Sat, 2020-11-21 at 17:46 -0800, Srinivas Pandruvada wrote:    
> > > > > > On Sat, 2020-11-21 at 17:56 +0000, Jonathan Cameron wrote:      
> > > > > > > On Thu, 19 Nov 2020 18:03:31 +0800
> > > > > > > Ye Xiang <xiang.ye@intel.com> wrote:
> > > > > > >       
> > > > > > > > The Hinge sensor is a common custom sensor on laptops. It
> > > > > > > > calculates
> > > > > > > > the angle between the lid (screen) and the base (keyboard).
> > > > > > > > In
> > > > > > > > addition,
> > > > > > > > it also exposes screen and the keyboard angels with respect
> > > > > > > > to
> > > > > > > > the
> > > > > > > > ground. Applications can easily get laptop's status in space
> > > > > > > > through
> > > > > > > > this sensor, in order to display appropriate user
> > > > > > > > interface.      
> > > > > > > 
> > > > > > > I'm a little unclear on why the 3 axes aren't treated as a
> > > > > > > single
> > > > > > > sensor.
> > > > > > > You seem to always grab the 3 together or am I missing
> > > > > > > something?
> > > > > > > 
> > > > > > > That will greatly simplify things and get rid of the need to
> > > > > > > have
> > > > > > > a shared trigger with the problems that causes in the previous
> > > > > > > patch.      
> > > > > > 
> > > > > > They are not three axes, they are independent. Xiang did try
> > > > > > adding
> > > > > > x,
> > > > > > y and z component to represent x as hinge, y as keyboard and z as
> > > > > > lid.
> > > > > > But I was not convinced.
> > > > > > The problem is that then what will be sysfs interface? They are
> > > > > > really
> > > > > > a three sensors. Or we create new interface to call
> > > > > > in_angl_raw_keyboard
> > > > > > in_angl_raw_screen
> > > > > > in_angl_raw_lid.
> > > > > >       
> > > > > You seem to indicate this is possible now some new "label" patch.
> > > > > Is this the patch?
> > > > > commit 2c3d0c9ffd24d9b4c62c5dfb2104695a614be28c
> > > > > Author: Phil Reid <preid@electromag.com.au>
> > > > > Date:   Thu Sep 19 22:36:08 2019 +0800    
> > > > 
> > > > Nope, this one 
> > > > https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio.git/commit/?id=1d4ef9b39ebecca827642b8897d2d79ea2026682
> > > > 
> > > > The one above adds a per device label which wouldn't be much use for
> > > > your
> > > > case, but this one adds a per channel label.
> > > > 
> > > > Done via a read_label callback.
> > > > 
> > > > Here you'd want to use indexed channels so something like.
> > > > 
> > > > in_angl0_raw
> > > > in_angl1_raw
> > > > in_angl2_raw
> > > > 
> > > > and
> > > > 
> > > > in_angl0_label = keyboard
> > > > in_angl1_label = screen
> > > > in_angl2_label = lid    
> > > 
> > > Thanks Jonathan. This will make the job easier.
> > > Xiang,
> > > You can use this method. Then you will not need other changes except
> > > patch 1/4.
> > > Also add a documentation patch to explain the mapping.  
> > 
> > Ah.  So we have a slightly problem with sysfs ABI docs at the moment.
> > The scripts that auto generate the html and similar docs from them
> > don't cope with the same name of attribute in multiple documentation
> > files.
> > 
> > https://lore.kernel.org/linux-iio/20201110082658.2edc1ab5@coco.lan/
> > 
> > The upshot being we can't have more specific docs for a particular
> > part that match up with the generic docs.  That will apply in this
> > case.
> > 
> > So for now, our solution is to put it in the main docs, but provide
> > a subsection in there talking about more specific constraints for
> > a particular device.
> > 
> > Note I haven't actually proposed any fixes for this problem yet so
> > you get to do the first one ;)
> > 
> > Thanks,
> > 
> > Jonathan  
> @Srinivas
> Yes, I will try this indexed channel and label based method.
> 
> @Jonathan
> So, I need to add in_angl0_raw, in_angl1_raw, in_angl2_raw and in_angl0_label,
> in_angl1_label,in_angl2_label description in sysfs-bus-iio. such as
> 
> What:		/sys/bus/iio/devices/iio:deviceX/in_angl0_raw
> What:		/sys/bus/iio/devices/iio:deviceX/in_angl1_raw
> What:		/sys/bus/iio/devices/iio:deviceX/in_angl2_raw
You can use a wild card which in this case would give you one line that says

  What:         /sys/bus/iio/devices/iio:deviceX/in_anglY_raw

> KernelVersion:	5.12
> Contact:	linux-iio@vger.kernel.org
> Description:
> 		Angle of rotation. Units after application of scale and offset
> 		are radians.
> 
> What:		/sys/bus/iio/devices/iio:deviceX/in_angl0_label
> What:		/sys/bus/iio/devices/iio:deviceX/in_angl1_label
> What:		/sys/bus/iio/devices/iio:deviceX/in_angl2_label

As above, wild card is fine.

> KernelVersion:	5.12
> Contact:	linux-iio@vger.kernel.org
> Description:
> 		Optional symbolic label to a device channel.
I'd add something device specific here even though it's in the main docs.

                For intel,hid-hinge values are: hinge, keyboard, screen


> 
> 
> Am i right?
Almost with those tweaks above to give a bit more info and keep it a little
more compact.

Thanks,

Jonathan

> 
> > 
> > 
> >   
> > > 
> > > Thanks,
> > > Srinivas
> > >   
> > > > 
> > > > 
> > > >     
> > > > > Ideally, one iio device here is much easy to manage as other HID
> > > > > sensors. If we can add something other that "x", "y" and "z"
> > > > > component.    
> > > > 
> > > > Agreed, using axes makes no real sense here and extended_name is
> > > > just a mess from ABI point of view.  Trying to solve this was the
> > > > reason we added the _label interface.
> > > > 
> > > > Jonathan
> > > > 
> > > >     
> > > > > Thanks,
> > > > > Srinivas
> > > > >     
> > > > > > Thanks,
> > > > > > Srinivas
> > > > > > 
> > > > > >       
> > > > > > > Thanks,
> > > > > > > 
> > > > > > > Jonathan
> > > > > > >       
> > > > > > > > Signed-off-by: Ye Xiang <xiang.ye@intel.com>
> > > > > > > > ---
> > > > > > > >  .../hid-sensors/hid-sensor-attributes.c       |   2 +
> > > > > > > >  drivers/iio/position/Kconfig                  |  16 +
> > > > > > > >  drivers/iio/position/Makefile                 |   3 +
> > > > > > > >  .../iio/position/hid-sensor-custom-hinge.c    | 412
> > > > > > > > ++++++++++++++++++      
> > > > > > > 
> > > > > > > Given it's custom probably needs a more specific name.  I guess
> > > > > > > hid-sensor-custom-intel-hinge.c might be safe?
> > > > > > > 
> > > > > > > Same for other places we need names in here.
> > > > > > >       
> > > > > > > >  4 files changed, 433 insertions(+)
> > > > > > > >  create mode 100644 drivers/iio/position/hid-sensor-custom-
> > > > > > > > hinge.c
> > > > > > > > 
> > > > > > > > diff --git a/drivers/iio/common/hid-sensors/hid-sensor-
> > > > > > > > attributes.c 
> > > > > > > > b/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> > > > > > > > index 442ff787f7af..5b822a4298a0 100644
> > > > > > > > --- a/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> > > > > > > > +++ b/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> > > > > > > > @@ -71,6 +71,8 @@ static struct {
> > > > > > > >  	{HID_USAGE_SENSOR_TEMPERATURE,
> > > > > > > > HID_USAGE_SENSOR_UNITS_DEGREES,
> > > > > > > > 1000, 0},
> > > > > > > >  
> > > > > > > >  	{HID_USAGE_SENSOR_HUMIDITY, 0, 1000, 0},
> > > > > > > > +	{HID_USAGE_SENSOR_HINGE, 0, 0, 17453293},
> > > > > > > > +	{HID_USAGE_SENSOR_HINGE,
> > > > > > > > HID_USAGE_SENSOR_UNITS_DEGREES, 0,
> > > > > > > > 17453293},
> > > > > > > >  };
> > > > > > > >  
> > > > > > > >  static void simple_div(int dividend, int divisor, int
> > > > > > > > *whole,
> > > > > > > > diff --git a/drivers/iio/position/Kconfig
> > > > > > > > b/drivers/iio/position/Kconfig
> > > > > > > > index eda67f008c5b..0346f6f2b422 100644
> > > > > > > > --- a/drivers/iio/position/Kconfig
> > > > > > > > +++ b/drivers/iio/position/Kconfig
> > > > > > > > @@ -16,4 +16,20 @@ config IQS624_POS
> > > > > > > >  	  To compile this driver as a module, choose M here:
> > > > > > > > the module
> > > > > > > >  	  will be called iqs624-pos.
> > > > > > > >  
> > > > > > > > +config HID_SENSOR_CUSTOM_HINGE
> > > > > > > > +	depends on HID_SENSOR_HUB
> > > > > > > > +	select IIO_BUFFER
> > > > > > > > +	select IIO_TRIGGERED_BUFFER
> > > > > > > > +	select HID_SENSOR_IIO_COMMON
> > > > > > > > +	select HID_SENSOR_IIO_TRIGGER
> > > > > > > > +	tristate "HID Hinge"
> > > > > > > > +	help
> > > > > > > > +	  This sensor present three angles, hinge angel, screen
> > > > > > > > angles
> > > > > > > > +	  and keyboard angle respect to horizon (ground).
> > > > > > > > +	  Say yes here to build support for the HID SENSOR
> > > > > > > > CUSTOM
> > > > > > > > +	  HINGE.      
> > > > > > > 
> > > > > > > Capitalization is a bit odd looking. I'd drop it.
> > > > > > >       
> > > > > > > > +
> > > > > > > > +	  To compile this driver as a module, choose M here:
> > > > > > > > the
> > > > > > > > +	  module will be called hid-sensor-custom-hinge.
> > > > > > > > +
> > > > > > > >  endmenu
> > > > > > > > diff --git a/drivers/iio/position/Makefile
> > > > > > > > b/drivers/iio/position/Makefile
> > > > > > > > index 3cbe7a734352..7a6225977a01 100644
> > > > > > > > --- a/drivers/iio/position/Makefile
> > > > > > > > +++ b/drivers/iio/position/Makefile
> > > > > > > > @@ -5,3 +5,6 @@
> > > > > > > >  # When adding new entries keep the list in alphabetical
> > > > > > > > order
> > > > > > > >  
> > > > > > > >  obj-$(CONFIG_IQS624_POS)	+= iqs624-pos.o
> > > > > > > > +
> > > > > > > > +obj-$(CONFIG_HID_SENSOR_CUSTOM_HINGE) += hid-sensor-custom-
> > > > > > > > hinge.o      
> > > > > > > 
> > > > > > > Alphabetical order preferred.
> > > > > > >       
> > > > > > > > +ccflags-y	+= -I$(srctree)/drivers/iio/common/hid-
> > > > > > > > sensors      
> > > > > > > 
> > > > > > > Why?
> > > > > > >       
> > > > > > > > diff --git a/drivers/iio/position/hid-sensor-custom-hinge.c
> > > > > > > > b/drivers/iio/position/hid-sensor-custom-hinge.c
> > > > > > > > new file mode 100644
> > > > > > > > index 000000000000..a91b333f36fa
> > > > > > > > --- /dev/null
> > > > > > > > +++ b/drivers/iio/position/hid-sensor-custom-hinge.c
> > > > > > > > @@ -0,0 +1,412 @@
> > > > > > > > +// SPDX-License-Identifier: GPL-2.0-only
> > > > > > > > +/*
> > > > > > > > + * HID Sensors Driver
> > > > > > > > + * Copyright (c) 2020, Intel Corporation.
> > > > > > > > + */
> > > > > > > > +#include <linux/hid-sensor-hub.h>
> > > > > > > > +#include <linux/iio/buffer.h>
> > > > > > > > +#include <linux/iio/iio.h>
> > > > > > > > +#include <linux/platform_device.h>
> > > > > > > > +
> > > > > > > > +#include "hid-sensor-trigger.h"
> > > > > > > > +
> > > > > > > > +/* Channel definitions */
> > > > > > > > +static const struct iio_chan_spec hinge_channels[] = {
> > > > > > > > +	{ .type = IIO_ANGL,
> > > > > > > > +	  .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> > > > > > > > +	  .info_mask_shared_by_type =
> > > > > > > > +		  BIT(IIO_CHAN_INFO_OFFSET) |
> > > > > > > > BIT(IIO_CHAN_INFO_SCALE)
> > > > > > > > +		  BIT(IIO_CHAN_INFO_SAMP_FREQ) |
> > > > > > > > BIT(IIO_CHAN_INFO_HYSTERESIS),
> > > > > > > > +	  .scan_type.realbits = 16,
> > > > > > > > +	  .scan_type.storagebits = 32,      
> > > > > > > 
> > > > > > > It a bit odd to see a single channel that is 16 bits inside a
> > > > > > > 32
> > > > > > > bit
> > > > > > > with
> > > > > > > no shift or similar.  Why not just pack it into 16 bits?
> > > > > > >       
> > > > > > > > +	  .scan_type.sign = 's',
> > > > > > > > +	  .scan_index = 0 },
> > > > > > > > +
> > > > > > > > +	IIO_CHAN_SOFT_TIMESTAMP(1)
> > > > > > > > +};
> > > > > > > > +
> > > > > > > > +struct hinge_state {
> > > > > > > > +	struct iio_dev *indio_dev;
> > > > > > > > +	struct hid_sensor_hub_attribute_info hinge;
> > > > > > > > +	/* Reserve for 1 channel + pading + timestamp */
> > > > > > > > +	u32 hinge_val[1 + 3];      
> > > > > > > 
> > > > > > > __aligned(8)
> > > > > > > 
> > > > > > > see below for requirements on this.
> > > > > > > Perhaps better to use
> > > > > > > 
> > > > > > > 	struct hinge_scan {
> > > > > > > 		u32 val;
> > > > > > > 		s64 timestamp __aligned(8); // Note this is
> > > > > > > needed for
> > > > > > > x86_32
> > > > > > > 	} scan;
> > > > > > >       
> > > > > > > > +	int scale_pre_decml;
> > > > > > > > +	int scale_post_decml;
> > > > > > > > +	int scale_precision;
> > > > > > > > +	int value_offset;
> > > > > > > > +	int64_t timestamp;
> > > > > > > > +	u32 hinge_address;
> > > > > > > > +};
> > > > > > > > +
> > > > > > > > +#define IIO_DEV_NUM 3      
> > > > > > > 
> > > > > > > That needs a prefix to make it clear it's not a generic
> > > > > > > constant
> > > > > > > but is specific to this driver.
> > > > > > >       
> > > > > > > > +
> > > > > > > > +struct hinge_group {
> > > > > > > > +	struct hinge_state *hg_states[IIO_DEV_NUM];
> > > > > > > > +	struct hid_sensor_hub_callbacks callbacks;
> > > > > > > > +	struct hid_sensor_common common_attributes;
> > > > > > > > +};
> > > > > > > > +
> > > > > > > > +static struct hinge_group *hg_group;      
> > > > > > > 
> > > > > > > We shouldn't see globals like this. Please figure out how to
> > > > > > > avoid
> > > > > > > it.
> > > > > > >       
> > > > > > > > +
> > > > > > > > +/* Channel read_raw handler */
> > > > > > > > +static int hinge_read_raw(struct iio_dev *indio_dev,
> > > > > > > > +			  struct iio_chan_spec const *chan, int
> > > > > > > > *val,
> > > > > > > > int *val2,
> > > > > > > > +			  long mask)
> > > > > > > > +{
> > > > > > > > +	struct hinge_state *hg_state = iio_priv(indio_dev);
> > > > > > > > +	struct hid_sensor_hub_device *hsdev;
> > > > > > > > +	int report_id = -1;
> > > > > > > > +	int ret_type;
> > > > > > > > +	s32 min;
> > > > > > > > +
> > > > > > > > +	hsdev = hg_group->common_attributes.hsdev;
> > > > > > > > +
> > > > > > > > +	*val = 0;
> > > > > > > > +	*val2 = 0;
> > > > > > > > +	switch (mask) {
> > > > > > > > +	case IIO_CHAN_INFO_RAW:
> > > > > > > > +		hid_sensor_power_state(&hg_group-    
> > > > > > > > >common_attributes,    
> > > > > > > > true);
> > > > > > > > +		report_id = hg_state->hinge.report_id;
> > > > > > > > +		min = hg_state->hinge.logical_minimum;
> > > > > > > > +		if (report_id < 0) {
> > > > > > > > +			*val = 0;
> > > > > > > > +			hid_sensor_power_state(&hg_group-      
> > > > > > > > > common_attributes,      
> > > > > > > > +					       false);
> > > > > > > > +			return -EINVAL;
> > > > > > > > +		}
> > > > > > > > +
> > > > > > > > +		*val = sensor_hub_input_attr_get_raw_value(
> > > > > > > > +			hg_group->common_attributes.hsdev,
> > > > > > > > hsdev-      
> > > > > > > > > usage,      
> > > > > > > > +			hg_state->hinge_address, report_id,
> > > > > > > > SENSOR_HUB_SYNC,
> > > > > > > > +			min < 0);
> > > > > > > > +
> > > > > > > > +		hid_sensor_power_state(&hg_group-    
> > > > > > > > >common_attributes,    
> > > > > > > > false);
> > > > > > > > +		ret_type = IIO_VAL_INT;
> > > > > > > > +		break;
> > > > > > > > +	case IIO_CHAN_INFO_SCALE:
> > > > > > > > +		*val = hg_state->scale_pre_decml;
> > > > > > > > +		*val2 = hg_state->scale_post_decml;
> > > > > > > > +		ret_type = hg_state->scale_precision;
> > > > > > > > +		break;
> > > > > > > > +	case IIO_CHAN_INFO_OFFSET:
> > > > > > > > +		*val = hg_state->value_offset;
> > > > > > > > +		ret_type = IIO_VAL_INT;
> > > > > > > > +		break;
> > > > > > > > +	case IIO_CHAN_INFO_SAMP_FREQ:
> > > > > > > > +		ret_type = hid_sensor_read_samp_freq_value(
> > > > > > > > +			&hg_group->common_attributes, val,
> > > > > > > > val2);
> > > > > > > > +		break;
> > > > > > > > +	case IIO_CHAN_INFO_HYSTERESIS:
> > > > > > > > +		ret_type = hid_sensor_read_raw_hyst_value(
> > > > > > > > +			&hg_group->common_attributes, val,
> > > > > > > > val2);
> > > > > > > > +		break;
> > > > > > > > +	default:
> > > > > > > > +		ret_type = -EINVAL;
> > > > > > > > +		break;
> > > > > > > > +	}
> > > > > > > > +
> > > > > > > > +	return ret_type;
> > > > > > > > +}
> > > > > > > > +
> > > > > > > > +/* Channel write_raw handler */
> > > > > > > > +static int hinge_write_raw(struct iio_dev *indio_dev,
> > > > > > > > +			   struct iio_chan_spec const *chan,
> > > > > > > > int val,
> > > > > > > > int val2,
> > > > > > > > +			   long mask)
> > > > > > > > +{
> > > > > > > > +	int ret;
> > > > > > > > +
> > > > > > > > +	switch (mask) {
> > > > > > > > +	case IIO_CHAN_INFO_SAMP_FREQ:
> > > > > > > > +		ret = hid_sensor_write_samp_freq_value(
> > > > > > > > +			&hg_group->common_attributes, val,
> > > > > > > > val2);
> > > > > > > > +		break;
> > > > > > > > +	case IIO_CHAN_INFO_HYSTERESIS:
> > > > > > > > +		ret = hid_sensor_write_raw_hyst_value(
> > > > > > > > +			&hg_group->common_attributes, val,
> > > > > > > > val2);
> > > > > > > > +
> > > > > > > > +		break;
> > > > > > > > +	default:
> > > > > > > > +		ret = -EINVAL;
> > > > > > > > +	}
> > > > > > > > +
> > > > > > > > +	return ret;
> > > > > > > > +}
> > > > > > > > +
> > > > > > > > +static const struct iio_info hinge_info = {
> > > > > > > > +	.read_raw = &hinge_read_raw,
> > > > > > > > +	.write_raw = &hinge_write_raw,
> > > > > > > > +};
> > > > > > > > +
> > > > > > > > +/*
> > > > > > > > + * Function to push data to buffer;
> > > > > > > > + * wrapper added for symmetry with other hid-sensor drivers
> > > > > > > > + */
> > > > > > > > +static void hid_sensor_push_data(struct iio_dev *indio_dev,
> > > > > > > > void
> > > > > > > > *data, int len,      
> > > > > > > 
> > > > > > > This doesn't seem to be generic, so don't name it as such.
> > > > > > >       
> > > > > > > > +				 int64_t timestamp)
> > > > > > > > +{
> > > > > > > > +	iio_push_to_buffers_with_timestamp(indio_dev, data,
> > > > > > > > timestamp);      
> > > > > > > I hope that data buffer obeys the various rules needed by (and
> > > > > > > admittedly
> > > > > > > not that well documented) iio_push_to_buffers_with_timestamp()
> > > > > > > 
> > > > > > > 1. Needs to be 8 byte aligned.
> > > > > > > 2. Needs to have space for an aligned 8 byte timestamp at the
> > > > > > > end.
> > > > > > >       
> > > > > > > > +}
> > > > > > > > +
> > > > > > > > +/*
> > > > > > > > + * Callback handler to send event after all samples are
> > > > > > > > received
> > > > > > > > + * and captured.
> > > > > > > > + */
> > > > > > > > +static int hinge_proc_event(struct hid_sensor_hub_device
> > > > > > > > *hsdev,
> > > > > > > > +			    unsigned int usage_id, void *priv)
> > > > > > > > +{
> > > > > > > > +	int i;
> > > > > > > > +
> > > > > > > > +	for (i = 0; i < IIO_DEV_NUM; ++i) {      
> > > > > > > If we push for all sensors together, better to have
> > > > > > > this as a single iio_device with 3 channels.
> > > > > > > 
> > > > > > > Use the channel labels (just added to IIO) to identify which is
> > > > > > > which.
> > > > > > >       
> > > > > > > > +		struct hinge_state *hg_state;
> > > > > > > > +		struct iio_dev *indio_dev;
> > > > > > > > +
> > > > > > > > +		hg_state = hg_group->hg_states[i];
> > > > > > > > +		indio_dev = hg_state->indio_dev;
> > > > > > > > +
> > > > > > > > +		dev_dbg(&indio_dev->dev, "%s timestamp:%llu
> > > > > > > > scan_bytes:%d\n",
> > > > > > > > +			__func__, hg_state->timestamp,
> > > > > > > > indio_dev-      
> > > > > > > > > scan_bytes);      
> > > > > > > > +
> > > > > > > > +		if (!hg_state->timestamp)
> > > > > > > > +			hg_state->timestamp =
> > > > > > > > iio_get_time_ns(indio_dev);
> > > > > > > > +
> > > > > > > > +		hid_sensor_push_data(indio_dev, hg_state-    
> > > > > > > > >hinge_val,    
> > > > > > > > +				     sizeof(hg_state-    
> > > > > > > > >hinge_val),    
> > > > > > > > +				     hg_state->timestamp);
> > > > > > > > +
> > > > > > > > +		hg_state->timestamp = 0;
> > > > > > > > +	}
> > > > > > > > +
> > > > > > > > +	return 0;
> > > > > > > > +}
> > > > > > > > +
> > > > > > > > +/* Capture samples in local storage */
> > > > > > > > +static int hinge_capture_sample(struct hid_sensor_hub_device
> > > > > > > > *hsdev,
> > > > > > > > +				unsigned int usage_id, size_t
> > > > > > > > raw_len,
> > > > > > > > +				char *raw_data, void *priv)
> > > > > > > > +{
> > > > > > > > +	struct hinge_state *hg_state;
> > > > > > > > +	int offset;
> > > > > > > > +	int ret = -EINVAL;
> > > > > > > > +	int i;
> > > > > > > > +
> > > > > > > > +	if (usage_id == HID_USAGE_SENSOR_TIME_TIMESTAMP) {
> > > > > > > > +		for (i = 0; i < IIO_DEV_NUM; i++)
> > > > > > > > +			hg_group->hg_states[i]->timestamp =      
> > > > > > > 
> > > > > > > This rather implies all the data is captured together... If so
> > > > > > > single
> > > > > > > iio_device may make more sense.
> > > > > > >       
> > > > > > > > +				hid_sensor_convert_timestamp(
> > > > > > > > +					&hg_group-    
> > > > > > > > >common_attributes,    
> > > > > > > > +					*(int64_t *)raw_data);
> > > > > > > > +		return 0;
> > > > > > > > +	}
> > > > > > > > +
> > > > > > > > +	switch (usage_id) {
> > > > > > > > +	case HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_1:
> > > > > > > > +	case HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_2:
> > > > > > > > +	case HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_3:
> > > > > > > > +		offset = usage_id -
> > > > > > > > HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_1;
> > > > > > > > +		hg_state = hg_group->hg_states[offset];
> > > > > > > > +		hg_state->hinge_val[0] = *(u32 *)raw_data;
> > > > > > > > +		ret = 0;      
> > > > > > > 
> > > > > > > 		return 0;
> > > > > > >       
> > > > > > > > +		break;
> > > > > > > > +	default:      
> > > > > > > 		return -EINVAL;      
> > > > > > > > +		break;
> > > > > > > > +	}
> > > > > > > > +
> > > > > > > > +	return ret;
> > > > > > > > +}
> > > > > > > > +
> > > > > > > > +/* Parse report which is specific to an usage id */
> > > > > > > > +static int hinge_parse_report(struct platform_device *pdev,
> > > > > > > > +			      struct hid_sensor_hub_device
> > > > > > > > *hsdev,
> > > > > > > > +			      unsigned int usage_id, unsigned
> > > > > > > > int
> > > > > > > > attr_usage_id,
> > > > > > > > +			      struct hinge_state *st)
> > > > > > > > +{
> > > > > > > > +	int ret;
> > > > > > > > +
> > > > > > > > +	ret = sensor_hub_input_get_attribute_info(
> > > > > > > > +		hsdev, HID_INPUT_REPORT, usage_id,
> > > > > > > > attr_usage_id, &st-      
> > > > > > > > > hinge);      
> > > > > > > > +	if (ret < 0)
> > > > > > > > +		return ret;
> > > > > > > > +
> > > > > > > > +	st->hinge_address = attr_usage_id;
> > > > > > > > +	st->scale_precision =
> > > > > > > > +		hid_sensor_format_scale(HID_USAGE_SENSOR_HINGE,
> > > > > > > > &st-      
> > > > > > > > > hinge,      
> > > > > > > > +					&st->scale_pre_decml,
> > > > > > > > +					&st->scale_post_decml);
> > > > > > > > +
> > > > > > > > +	/* Set Sensitivity field ids, when there is no
> > > > > > > > individual
> > > > > > > > modifier */
> > > > > > > > +	if (hg_group->common_attributes.sensitivity.index < 0)
> > > > > > > > {
> > > > > > > > +		sensor_hub_input_get_attribute_info(
> > > > > > > > +			hsdev, HID_FEATURE_REPORT, usage_id,
> > > > > > > > +			HID_USAGE_SENSOR_DATA_MOD_CHANGE_SENSIT
> > > > > > > > IVITY_AB
> > > > > > > > S |
> > > > > > > > +				HID_USAGE_SENSOR_DATA_FIELD_CUS
> > > > > > > > TOM_VALU
> > > > > > > > E_1,
> > > > > > > > +			&hg_group-    
> > > > > > > > >common_attributes.sensitivity);    
> > > > > > > > +		dev_dbg(&pdev->dev, "Sensitivity index:report
> > > > > > > > %d:%d\n",
> > > > > > > > +			hg_group-    
> > > > > > > > >common_attributes.sensitivity.index,    
> > > > > > > > +			hg_group-      
> > > > > > > > > common_attributes.sensitivity.report_id);      
> > > > > > > > +	}
> > > > > > > > +
> > > > > > > > +	return ret;
> > > > > > > > +}
> > > > > > > > +
> > > > > > > > +/* Function to initialize the processing for usage id */
> > > > > > > > +static int hinge_add_iio_device(struct platform_device
> > > > > > > > *pdev,
> > > > > > > > int
> > > > > > > > index,
> > > > > > > > +				const char *name, struct
> > > > > > > > hinge_state
> > > > > > > > **st)
> > > > > > > > +{
> > > > > > > > +	struct hid_sensor_hub_device *hsdev = pdev-    
> > > > > > > > >dev.platform_data;    
> > > > > > > > +	struct hinge_state *hg_state;
> > > > > > > > +	struct iio_dev *indio_dev;
> > > > > > > > +	int ret;
> > > > > > > > +
> > > > > > > > +	indio_dev =
> > > > > > > > +		devm_iio_device_alloc(&pdev->dev, sizeof(struct
> > > > > > > > hinge_state));      
> > > > > > > 
> > > > > > > sizeof (*hg_state) preferred.
> > > > > > >       
> > > > > > > > +	if (indio_dev == NULL)
> > > > > > > > +		return -ENOMEM;
> > > > > > > > +
> > > > > > > > +	hg_state = iio_priv(indio_dev);
> > > > > > > > +	hg_state->indio_dev = indio_dev;
> > > > > > > > +
> > > > > > > > +	indio_dev->num_channels = ARRAY_SIZE(hinge_channels);
> > > > > > > > +	indio_dev->channels =
> > > > > > > > +		kmemdup(hinge_channels, sizeof(hinge_channels),
> > > > > > > > GFP_KERNEL);      
> > > > > > > 
> > > > > > > I don't immediately see anything that is modifying channels. As
> > > > > > > such
> > > > > > > you
> > > > > > > should be able have it shared by all the instances.
> > > > > > >       
> > > > > > > > +	if (!indio_dev->channels)
> > > > > > > > +		return -ENOMEM;
> > > > > > > > +
> > > > > > > > +	ret = hinge_parse_report(
> > > > > > > > +		pdev, hsdev, hsdev->usage,
> > > > > > > > +		HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_1 +
> > > > > > > > index,
> > > > > > > > hg_state);
> > > > > > > > +	if (ret) {
> > > > > > > > +		dev_err(&pdev->dev, "failed to setup
> > > > > > > > attributes\n");
> > > > > > > > +		goto error_free_dev_mem;
> > > > > > > > +	}
> > > > > > > > +
> > > > > > > > +	indio_dev->dev.parent = &pdev->dev;
> > > > > > > > +	indio_dev->info = &hinge_info;
> > > > > > > > +	indio_dev->name = name;
> > > > > > > > +	indio_dev->modes = INDIO_DIRECT_MODE;
> > > > > > > > +
> > > > > > > > +	ret = hid_sensor_setup_trigger(indio_dev, name,
> > > > > > > > +				       &hg_group-    
> > > > > > > > >common_attributes);    
> > > > > > > > +	if (ret < 0) {
> > > > > > > > +		dev_err(&pdev->dev, "trigger setup failed\n");
> > > > > > > > +		goto error_free_dev_mem;
> > > > > > > > +	}
> > > > > > > > +
> > > > > > > > +	ret = iio_device_register(indio_dev);
> > > > > > > > +	if (ret) {
> > > > > > > > +		dev_err(&pdev->dev, "device register
> > > > > > > > failed\n");
> > > > > > > > +		goto error_remove_trigger;
> > > > > > > > +	}
> > > > > > > > +
> > > > > > > > +	*st = hg_state;
> > > > > > > > +
> > > > > > > > +	return ret;
> > > > > > > > +
> > > > > > > > +error_remove_trigger:
> > > > > > > > +	hid_sensor_remove_trigger(indio_dev, &hg_group-      
> > > > > > > > > common_attributes);      
> > > > > > > > +error_free_dev_mem:
> > > > > > > > +	kfree(indio_dev->channels);
> > > > > > > > +	return ret;
> > > > > > > > +}
> > > > > > > > +
> > > > > > > > +/* Function to deinitialize the processing for usage id */
> > > > > > > > +static int hinge_remove_iio_device(struct platform_device
> > > > > > > > *pdev,
> > > > > > > > int index)
> > > > > > > > +{
> > > > > > > > +	struct hinge_state *hg_state = hg_group-    
> > > > > > > > >hg_states[index];    
> > > > > > > > +	struct iio_dev *indio_dev = hg_state->indio_dev;
> > > > > > > > +
> > > > > > > > +	iio_device_unregister(indio_dev);
> > > > > > > > +	hid_sensor_remove_trigger(indio_dev, &hg_group-      
> > > > > > > > > common_attributes);      
> > > > > > > > +	kfree(indio_dev->channels);
> > > > > > > > +
> > > > > > > > +	return 0;
> > > > > > > > +}
> > > > > > > > +
> > > > > > > > +static int hid_hinge_probe(struct platform_device *pdev)
> > > > > > > > +{
> > > > > > > > +	struct hinge_state *hg_state;
> > > > > > > > +	struct hid_sensor_hub_device *hsdev = pdev-    
> > > > > > > > >dev.platform_data;    
> > > > > > > > +	static const char *const names[] = { "hinge", "screen",
> > > > > > > > "keyboard" };
> > > > > > > > +	int ret;
> > > > > > > > +	int i;
> > > > > > > > +
> > > > > > > > +	hg_group = devm_kzalloc(&pdev->dev, sizeof(struct
> > > > > > > > hinge_group),
> > > > > > > > +				GFP_KERNEL);      
> > > > > > > 
> > > > > > > As mentioned above, I'd really not expect to see a global like
> > > > > > > this.
> > > > > > > Technically nothing stops there being more than one instance of
> > > > > > > this
> > > > > > > device on a platform (even if that would be a bit odd) + it's
> > > > > > > almost
> > > > > > > always cleaner to not use a global in the first place.
> > > > > > >       
> > > > > > > > +	if (!hg_group)
> > > > > > > > +		return -ENOMEM;
> > > > > > > > +
> > > > > > > > +	hg_group->common_attributes.hsdev = hsdev;
> > > > > > > > +	hg_group->common_attributes.pdev = pdev;
> > > > > > > > +
> > > > > > > > +	ret = hid_sensor_parse_common_attributes(hsdev, hsdev-    
> > > > > > > > >usage,    
> > > > > > > > +						 &hg_group-      
> > > > > > > > > common_attributes);      
> > > > > > > > +	if (ret) {
> > > > > > > > +		dev_err(&pdev->dev, "failed to setup common
> > > > > > > > attributes\n");
> > > > > > > > +		return ret;
> > > > > > > > +	}
> > > > > > > > +
> > > > > > > > +	atomic_set(&hg_group->common_attributes.data_ready, 0);
> > > > > > > > +	for (i = 0; i < IIO_DEV_NUM; i++) {
> > > > > > > > +		ret = hinge_add_iio_device(pdev, i, names[i],
> > > > > > > > &hg_state);
> > > > > > > > +		if (ret)
> > > > > > > > +			goto err_probe;
> > > > > > > > +
> > > > > > > > +		hg_group->hg_states[i] = hg_state;
> > > > > > > > +	}
> > > > > > > > +
> > > > > > > > +	/* use the first iio device to do the PM */
> > > > > > > > +	platform_set_drvdata(pdev, hg_group->hg_states[0]-    
> > > > > > > > >indio_dev);    
> > > > > > > > +
> > > > > > > > +	hg_group->callbacks.send_event = hinge_proc_event;
> > > > > > > > +	hg_group->callbacks.capture_sample =
> > > > > > > > hinge_capture_sample;
> > > > > > > > +	hg_group->callbacks.pdev = pdev;
> > > > > > > > +	ret = sensor_hub_register_callback(hsdev, hsdev->usage,
> > > > > > > > +					   &hg_group-    
> > > > > > > > >callbacks);    
> > > > > > > > +	if (ret < 0)
> > > > > > > > +		dev_err(&pdev->dev, "callback reg failed\n");
> > > > > > > > +
> > > > > > > > +	return ret;
> > > > > > > > +
> > > > > > > > +err_probe:
> > > > > > > > +	for (i--; i >= 0; i--)
> > > > > > > > +		hinge_remove_iio_device(pdev, i);
> > > > > > > > +
> > > > > > > > +	return ret;
> > > > > > > > +}
> > > > > > > > +
> > > > > > > > +/* Function to deinitialize the processing for usage id */
> > > > > > > > +static int hid_hinge_remove(struct platform_device *pdev)
> > > > > > > > +{
> > > > > > > > +	struct hid_sensor_hub_device *hsdev = pdev-    
> > > > > > > > >dev.platform_data;    
> > > > > > > > +	int i;
> > > > > > > > +
> > > > > > > > +	sensor_hub_remove_callback(hsdev, hsdev->usage);
> > > > > > > > +
> > > > > > > > +	for (i = 0; i < IIO_DEV_NUM; i++)
> > > > > > > > +		hinge_remove_iio_device(pdev, i);
> > > > > > > > +
> > > > > > > > +	return 0;
> > > > > > > > +}
> > > > > > > > +
> > > > > > > > +static const struct platform_device_id hid_hinge_ids[] = {
> > > > > > > > +	{
> > > > > > > > +		/* Format: HID-SENSOR-INT-
> > > > > > > > usage_id_in_hex_lowercase */
> > > > > > > > +		.name = "HID-SENSOR-INT-020b",
> > > > > > > > +	},
> > > > > > > > +	{ /* sentinel */ }
> > > > > > > > +};
> > > > > > > > +MODULE_DEVICE_TABLE(platform, hid_hinge_ids);
> > > > > > > > +
> > > > > > > > +static struct platform_driver hid_hinge_platform_driver = {
> > > > > > > > +	.id_table = hid_hinge_ids,
> > > > > > > > +	.driver = {
> > > > > > > > +		.name	= KBUILD_MODNAME,
> > > > > > > > +		.pm	= &hid_sensor_pm_ops,
> > > > > > > > +	},
> > > > > > > > +	.probe		= hid_hinge_probe,
> > > > > > > > +	.remove		= hid_hinge_remove,
> > > > > > > > +};
> > > > > > > > +module_platform_driver(hid_hinge_platform_driver);
> > > > > > > > +
> > > > > > > > +MODULE_DESCRIPTION("HID Sensor Custom Hinge");
> > > > > > > > +MODULE_AUTHOR("Ye Xiang <xiang.ye@intel.com>");
> > > > > > > > +MODULE_LICENSE("GPL");      
> >

Jonathan Cameron Nov. 24, 2020, 11:39 a.m. UTC | #10

> >   
> > > +
> > > +	  To compile this driver as a module, choose M here: the
> > > +	  module will be called hid-sensor-custom-hinge.
> > > +
> > >  endmenu
> > > diff --git a/drivers/iio/position/Makefile b/drivers/iio/position/Makefile
> > > index 3cbe7a734352..7a6225977a01 100644
> > > --- a/drivers/iio/position/Makefile
> > > +++ b/drivers/iio/position/Makefile
> > > @@ -5,3 +5,6 @@
> > >  # When adding new entries keep the list in alphabetical order
> > >  
> > >  obj-$(CONFIG_IQS624_POS)	+= iqs624-pos.o
> > > +
> > > +obj-$(CONFIG_HID_SENSOR_CUSTOM_HINGE) += hid-sensor-custom-hinge.o  
> > 
> > Alphabetical order preferred.
> >   
> > > +ccflags-y	+= -I$(srctree)/drivers/iio/common/hid-sensors  
> > 
> > Why?  
> hinge driver need to include #include "hid-sensor-trigger.h", if not using this cflag-y
> it should be #include "../common/hid-sensors/hid-sensor-trigger.h"

Even though that looks a bit ugly, I'd prefer that rather than having to realize we
were doing something not entirely obvious in the Makefile.

Thanks,

Jonathan

Ye Xiang Nov. 25, 2020, 2:39 a.m. UTC | #11

Hi,

On Tue, Nov 24, 2020 at 11:39:51AM +0000, Jonathan Cameron wrote:
> 
> > >   
> > > > +
> > > > +	  To compile this driver as a module, choose M here: the
> > > > +	  module will be called hid-sensor-custom-hinge.
> > > > +
> > > >  endmenu
> > > > diff --git a/drivers/iio/position/Makefile b/drivers/iio/position/Makefile
> > > > index 3cbe7a734352..7a6225977a01 100644
> > > > --- a/drivers/iio/position/Makefile
> > > > +++ b/drivers/iio/position/Makefile
> > > > @@ -5,3 +5,6 @@
> > > >  # When adding new entries keep the list in alphabetical order
> > > >  
> > > >  obj-$(CONFIG_IQS624_POS)	+= iqs624-pos.o
> > > > +
> > > > +obj-$(CONFIG_HID_SENSOR_CUSTOM_HINGE) += hid-sensor-custom-hinge.o  
> > > 
> > > Alphabetical order preferred.
> > >   
> > > > +ccflags-y	+= -I$(srctree)/drivers/iio/common/hid-sensors  
> > > 
> > > Why?  
> > hinge driver need to include #include "hid-sensor-trigger.h", if not using this cflag-y
> > it should be #include "../common/hid-sensors/hid-sensor-trigger.h"
> 
> Even though that looks a bit ugly, I'd prefer that rather than having to realize we
> were doing something not entirely obvious in the Makefile.
Okay, will remove ccflags-y in the makefile

Thanks
Ye, Xiang
> 
> Thanks,
> 
> Jonathan

Ye Xiang Nov. 25, 2020, 3:24 a.m. UTC | #12

On Tue, Nov 24, 2020 at 11:36:56AM +0000, Jonathan Cameron wrote:
> On Tue, 24 Nov 2020 11:30:50 +0800
> "Ye, Xiang" <xiang.ye@intel.com> wrote:
> 
> > On Sun, Nov 22, 2020 at 04:50:47PM +0000, Jonathan Cameron wrote:
> > > On Sun, 22 Nov 2020 15:51:18 +0000
> > > "Pandruvada, Srinivas" <srinivas.pandruvada@intel.com> wrote:
> > >   
> > > > On Sun, 2020-11-22 at 14:14 +0000, Jonathan Cameron wrote:  
> > > > > On Sun, 22 Nov 2020 02:14:16 +0000
> > > > > "Pandruvada, Srinivas" <srinivas.pandruvada@intel.com> wrote:
> > > > >     
> > > > > > On Sat, 2020-11-21 at 17:46 -0800, Srinivas Pandruvada wrote:    
> > > > > > > On Sat, 2020-11-21 at 17:56 +0000, Jonathan Cameron wrote:      
> > > > > > > > On Thu, 19 Nov 2020 18:03:31 +0800
> > > > > > > > Ye Xiang <xiang.ye@intel.com> wrote:
> > > > > > > >       
> > > > > > > > > The Hinge sensor is a common custom sensor on laptops. It
> > > > > > > > > calculates
> > > > > > > > > the angle between the lid (screen) and the base (keyboard).
> > > > > > > > > In
> > > > > > > > > addition,
> > > > > > > > > it also exposes screen and the keyboard angels with respect
> > > > > > > > > to
> > > > > > > > > the
> > > > > > > > > ground. Applications can easily get laptop's status in space
> > > > > > > > > through
> > > > > > > > > this sensor, in order to display appropriate user
> > > > > > > > > interface.      
> > > > > > > > 
> > > > > > > > I'm a little unclear on why the 3 axes aren't treated as a
> > > > > > > > single
> > > > > > > > sensor.
> > > > > > > > You seem to always grab the 3 together or am I missing
> > > > > > > > something?
> > > > > > > > 
> > > > > > > > That will greatly simplify things and get rid of the need to
> > > > > > > > have
> > > > > > > > a shared trigger with the problems that causes in the previous
> > > > > > > > patch.      
> > > > > > > 
> > > > > > > They are not three axes, they are independent. Xiang did try
> > > > > > > adding
> > > > > > > x,
> > > > > > > y and z component to represent x as hinge, y as keyboard and z as
> > > > > > > lid.
> > > > > > > But I was not convinced.
> > > > > > > The problem is that then what will be sysfs interface? They are
> > > > > > > really
> > > > > > > a three sensors. Or we create new interface to call
> > > > > > > in_angl_raw_keyboard
> > > > > > > in_angl_raw_screen
> > > > > > > in_angl_raw_lid.
> > > > > > >       
> > > > > > You seem to indicate this is possible now some new "label" patch.
> > > > > > Is this the patch?
> > > > > > commit 2c3d0c9ffd24d9b4c62c5dfb2104695a614be28c
> > > > > > Author: Phil Reid <preid@electromag.com.au>
> > > > > > Date:   Thu Sep 19 22:36:08 2019 +0800    
> > > > > 
> > > > > Nope, this one 
> > > > > https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio.git/commit/?id=1d4ef9b39ebecca827642b8897d2d79ea2026682
> > > > > 
> > > > > The one above adds a per device label which wouldn't be much use for
> > > > > your
> > > > > case, but this one adds a per channel label.
> > > > > 
> > > > > Done via a read_label callback.
> > > > > 
> > > > > Here you'd want to use indexed channels so something like.
> > > > > 
> > > > > in_angl0_raw
> > > > > in_angl1_raw
> > > > > in_angl2_raw
> > > > > 
> > > > > and
> > > > > 
> > > > > in_angl0_label = keyboard
> > > > > in_angl1_label = screen
> > > > > in_angl2_label = lid    
> > > > 
> > > > Thanks Jonathan. This will make the job easier.
> > > > Xiang,
> > > > You can use this method. Then you will not need other changes except
> > > > patch 1/4.
> > > > Also add a documentation patch to explain the mapping.  
> > > 
> > > Ah.  So we have a slightly problem with sysfs ABI docs at the moment.
> > > The scripts that auto generate the html and similar docs from them
> > > don't cope with the same name of attribute in multiple documentation
> > > files.
> > > 
> > > https://lore.kernel.org/linux-iio/20201110082658.2edc1ab5@coco.lan/
> > > 
> > > The upshot being we can't have more specific docs for a particular
> > > part that match up with the generic docs.  That will apply in this
> > > case.
> > > 
> > > So for now, our solution is to put it in the main docs, but provide
> > > a subsection in there talking about more specific constraints for
> > > a particular device.
> > > 
> > > Note I haven't actually proposed any fixes for this problem yet so
> > > you get to do the first one ;)
> > > 
> > > Thanks,
> > > 
> > > Jonathan  
> > @Srinivas
> > Yes, I will try this indexed channel and label based method.
> > 
> > @Jonathan
> > So, I need to add in_angl0_raw, in_angl1_raw, in_angl2_raw and in_angl0_label,
> > in_angl1_label,in_angl2_label description in sysfs-bus-iio. such as
> > 
> > What:		/sys/bus/iio/devices/iio:deviceX/in_angl0_raw
> > What:		/sys/bus/iio/devices/iio:deviceX/in_angl1_raw
> > What:		/sys/bus/iio/devices/iio:deviceX/in_angl2_raw
> You can use a wild card which in this case would give you one line that says
> 
>   What:         /sys/bus/iio/devices/iio:deviceX/in_anglY_raw
Good idea, Wild card can reduce repetition, will adopt it.
> 
> > KernelVersion:	5.12
> > Contact:	linux-iio@vger.kernel.org
> > Description:
> > 		Angle of rotation. Units after application of scale and offset
> > 		are radians.
> > 
> > What:		/sys/bus/iio/devices/iio:deviceX/in_angl0_label
> > What:		/sys/bus/iio/devices/iio:deviceX/in_angl1_label
> > What:		/sys/bus/iio/devices/iio:deviceX/in_angl2_label
> 
> As above, wild card is fine.
Ok.
> 
> > KernelVersion:	5.12
> > Contact:	linux-iio@vger.kernel.org
> > Description:
> > 		Optional symbolic label to a device channel.
> I'd add something device specific here even though it's in the main docs.
> 
>                 For intel,hid-hinge values are: hinge, keyboard, screen
yes, add some detail fo intel hinge sensor

Optional symbolic label for channel Y.
For Intel hid hinge sensor, the label values are:
hinge, keyboard, screen. It means the three channels 
each correspond respectively to hinge angle, keyboard angle,
and screen angle.

> 
> 
> > 
> > 
> > Am i right?
> Almost with those tweaks above to give a bit more info and keep it a little
> more compact.
> 
> Thanks,
> 
> Jonathan

yes, will revise the description according your advice. Thanks for review and comments

Thanks
Ye, Xiang
> 
> > 
> > > 
> > > 
> > >   
> > > > 
> > > > Thanks,
> > > > Srinivas
> > > >   
> > > > > 
> > > > > 
> > > > >     
> > > > > > Ideally, one iio device here is much easy to manage as other HID
> > > > > > sensors. If we can add something other that "x", "y" and "z"
> > > > > > component.    
> > > > > 
> > > > > Agreed, using axes makes no real sense here and extended_name is
> > > > > just a mess from ABI point of view.  Trying to solve this was the
> > > > > reason we added the _label interface.
> > > > > 
> > > > > Jonathan
> > > > > 
> > > > >     
> > > > > > Thanks,
> > > > > > Srinivas
> > > > > >     
> > > > > > > Thanks,
> > > > > > > Srinivas
> > > > > > > 
> > > > > > >       
> > > > > > > > Thanks,
> > > > > > > > 
> > > > > > > > Jonathan
> > > > > > > >       
> > > > > > > > > Signed-off-by: Ye Xiang <xiang.ye@intel.com>
> > > > > > > > > ---
> > > > > > > > >  .../hid-sensors/hid-sensor-attributes.c       |   2 +
> > > > > > > > >  drivers/iio/position/Kconfig                  |  16 +
> > > > > > > > >  drivers/iio/position/Makefile                 |   3 +
> > > > > > > > >  .../iio/position/hid-sensor-custom-hinge.c    | 412
> > > > > > > > > ++++++++++++++++++      
> > > > > > > > 
> > > > > > > > Given it's custom probably needs a more specific name.  I guess
> > > > > > > > hid-sensor-custom-intel-hinge.c might be safe?
> > > > > > > > 
> > > > > > > > Same for other places we need names in here.
> > > > > > > >       
> > > > > > > > >  4 files changed, 433 insertions(+)
> > > > > > > > >  create mode 100644 drivers/iio/position/hid-sensor-custom-
> > > > > > > > > hinge.c
> > > > > > > > > 
> > > > > > > > > diff --git a/drivers/iio/common/hid-sensors/hid-sensor-
> > > > > > > > > attributes.c 
> > > > > > > > > b/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> > > > > > > > > index 442ff787f7af..5b822a4298a0 100644
> > > > > > > > > --- a/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> > > > > > > > > +++ b/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> > > > > > > > > @@ -71,6 +71,8 @@ static struct {
> > > > > > > > >  	{HID_USAGE_SENSOR_TEMPERATURE,
> > > > > > > > > HID_USAGE_SENSOR_UNITS_DEGREES,
> > > > > > > > > 1000, 0},
> > > > > > > > >  
> > > > > > > > >  	{HID_USAGE_SENSOR_HUMIDITY, 0, 1000, 0},
> > > > > > > > > +	{HID_USAGE_SENSOR_HINGE, 0, 0, 17453293},
> > > > > > > > > +	{HID_USAGE_SENSOR_HINGE,
> > > > > > > > > HID_USAGE_SENSOR_UNITS_DEGREES, 0,
> > > > > > > > > 17453293},
> > > > > > > > >  };
> > > > > > > > >  
> > > > > > > > >  static void simple_div(int dividend, int divisor, int
> > > > > > > > > *whole,
> > > > > > > > > diff --git a/drivers/iio/position/Kconfig
> > > > > > > > > b/drivers/iio/position/Kconfig
> > > > > > > > > index eda67f008c5b..0346f6f2b422 100644
> > > > > > > > > --- a/drivers/iio/position/Kconfig
> > > > > > > > > +++ b/drivers/iio/position/Kconfig
> > > > > > > > > @@ -16,4 +16,20 @@ config IQS624_POS
> > > > > > > > >  	  To compile this driver as a module, choose M here:
> > > > > > > > > the module
> > > > > > > > >  	  will be called iqs624-pos.
> > > > > > > > >  
> > > > > > > > > +config HID_SENSOR_CUSTOM_HINGE
> > > > > > > > > +	depends on HID_SENSOR_HUB
> > > > > > > > > +	select IIO_BUFFER
> > > > > > > > > +	select IIO_TRIGGERED_BUFFER
> > > > > > > > > +	select HID_SENSOR_IIO_COMMON
> > > > > > > > > +	select HID_SENSOR_IIO_TRIGGER
> > > > > > > > > +	tristate "HID Hinge"
> > > > > > > > > +	help
> > > > > > > > > +	  This sensor present three angles, hinge angel, screen
> > > > > > > > > angles
> > > > > > > > > +	  and keyboard angle respect to horizon (ground).
> > > > > > > > > +	  Say yes here to build support for the HID SENSOR
> > > > > > > > > CUSTOM
> > > > > > > > > +	  HINGE.      
> > > > > > > > 
> > > > > > > > Capitalization is a bit odd looking. I'd drop it.
> > > > > > > >       
> > > > > > > > > +
> > > > > > > > > +	  To compile this driver as a module, choose M here:
> > > > > > > > > the
> > > > > > > > > +	  module will be called hid-sensor-custom-hinge.
> > > > > > > > > +
> > > > > > > > >  endmenu
> > > > > > > > > diff --git a/drivers/iio/position/Makefile
> > > > > > > > > b/drivers/iio/position/Makefile
> > > > > > > > > index 3cbe7a734352..7a6225977a01 100644
> > > > > > > > > --- a/drivers/iio/position/Makefile
> > > > > > > > > +++ b/drivers/iio/position/Makefile
> > > > > > > > > @@ -5,3 +5,6 @@
> > > > > > > > >  # When adding new entries keep the list in alphabetical
> > > > > > > > > order
> > > > > > > > >  
> > > > > > > > >  obj-$(CONFIG_IQS624_POS)	+= iqs624-pos.o
> > > > > > > > > +
> > > > > > > > > +obj-$(CONFIG_HID_SENSOR_CUSTOM_HINGE) += hid-sensor-custom-
> > > > > > > > > hinge.o      
> > > > > > > > 
> > > > > > > > Alphabetical order preferred.
> > > > > > > >       
> > > > > > > > > +ccflags-y	+= -I$(srctree)/drivers/iio/common/hid-
> > > > > > > > > sensors      
> > > > > > > > 
> > > > > > > > Why?
> > > > > > > >       
> > > > > > > > > diff --git a/drivers/iio/position/hid-sensor-custom-hinge.c
> > > > > > > > > b/drivers/iio/position/hid-sensor-custom-hinge.c
> > > > > > > > > new file mode 100644
> > > > > > > > > index 000000000000..a91b333f36fa
> > > > > > > > > --- /dev/null
> > > > > > > > > +++ b/drivers/iio/position/hid-sensor-custom-hinge.c
> > > > > > > > > @@ -0,0 +1,412 @@
> > > > > > > > > +// SPDX-License-Identifier: GPL-2.0-only
> > > > > > > > > +/*
> > > > > > > > > + * HID Sensors Driver
> > > > > > > > > + * Copyright (c) 2020, Intel Corporation.
> > > > > > > > > + */
> > > > > > > > > +#include <linux/hid-sensor-hub.h>
> > > > > > > > > +#include <linux/iio/buffer.h>
> > > > > > > > > +#include <linux/iio/iio.h>
> > > > > > > > > +#include <linux/platform_device.h>
> > > > > > > > > +
> > > > > > > > > +#include "hid-sensor-trigger.h"
> > > > > > > > > +
> > > > > > > > > +/* Channel definitions */
> > > > > > > > > +static const struct iio_chan_spec hinge_channels[] = {
> > > > > > > > > +	{ .type = IIO_ANGL,
> > > > > > > > > +	  .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> > > > > > > > > +	  .info_mask_shared_by_type =
> > > > > > > > > +		  BIT(IIO_CHAN_INFO_OFFSET) |
> > > > > > > > > BIT(IIO_CHAN_INFO_SCALE)
> > > > > > > > > +		  BIT(IIO_CHAN_INFO_SAMP_FREQ) |
> > > > > > > > > BIT(IIO_CHAN_INFO_HYSTERESIS),
> > > > > > > > > +	  .scan_type.realbits = 16,
> > > > > > > > > +	  .scan_type.storagebits = 32,      
> > > > > > > > 
> > > > > > > > It a bit odd to see a single channel that is 16 bits inside a
> > > > > > > > 32
> > > > > > > > bit
> > > > > > > > with
> > > > > > > > no shift or similar.  Why not just pack it into 16 bits?
> > > > > > > >       
> > > > > > > > > +	  .scan_type.sign = 's',
> > > > > > > > > +	  .scan_index = 0 },
> > > > > > > > > +
> > > > > > > > > +	IIO_CHAN_SOFT_TIMESTAMP(1)
> > > > > > > > > +};
> > > > > > > > > +
> > > > > > > > > +struct hinge_state {
> > > > > > > > > +	struct iio_dev *indio_dev;
> > > > > > > > > +	struct hid_sensor_hub_attribute_info hinge;
> > > > > > > > > +	/* Reserve for 1 channel + pading + timestamp */
> > > > > > > > > +	u32 hinge_val[1 + 3];      
> > > > > > > > 
> > > > > > > > __aligned(8)
> > > > > > > > 
> > > > > > > > see below for requirements on this.
> > > > > > > > Perhaps better to use
> > > > > > > > 
> > > > > > > > 	struct hinge_scan {
> > > > > > > > 		u32 val;
> > > > > > > > 		s64 timestamp __aligned(8); // Note this is
> > > > > > > > needed for
> > > > > > > > x86_32
> > > > > > > > 	} scan;
> > > > > > > >       
> > > > > > > > > +	int scale_pre_decml;
> > > > > > > > > +	int scale_post_decml;
> > > > > > > > > +	int scale_precision;
> > > > > > > > > +	int value_offset;
> > > > > > > > > +	int64_t timestamp;
> > > > > > > > > +	u32 hinge_address;
> > > > > > > > > +};
> > > > > > > > > +
> > > > > > > > > +#define IIO_DEV_NUM 3      
> > > > > > > > 
> > > > > > > > That needs a prefix to make it clear it's not a generic
> > > > > > > > constant
> > > > > > > > but is specific to this driver.
> > > > > > > >       
> > > > > > > > > +
> > > > > > > > > +struct hinge_group {
> > > > > > > > > +	struct hinge_state *hg_states[IIO_DEV_NUM];
> > > > > > > > > +	struct hid_sensor_hub_callbacks callbacks;
> > > > > > > > > +	struct hid_sensor_common common_attributes;
> > > > > > > > > +};
> > > > > > > > > +
> > > > > > > > > +static struct hinge_group *hg_group;      
> > > > > > > > 
> > > > > > > > We shouldn't see globals like this. Please figure out how to
> > > > > > > > avoid
> > > > > > > > it.
> > > > > > > >       
> > > > > > > > > +
> > > > > > > > > +/* Channel read_raw handler */
> > > > > > > > > +static int hinge_read_raw(struct iio_dev *indio_dev,
> > > > > > > > > +			  struct iio_chan_spec const *chan, int
> > > > > > > > > *val,
> > > > > > > > > int *val2,
> > > > > > > > > +			  long mask)
> > > > > > > > > +{
> > > > > > > > > +	struct hinge_state *hg_state = iio_priv(indio_dev);
> > > > > > > > > +	struct hid_sensor_hub_device *hsdev;
> > > > > > > > > +	int report_id = -1;
> > > > > > > > > +	int ret_type;
> > > > > > > > > +	s32 min;
> > > > > > > > > +
> > > > > > > > > +	hsdev = hg_group->common_attributes.hsdev;
> > > > > > > > > +
> > > > > > > > > +	*val = 0;
> > > > > > > > > +	*val2 = 0;
> > > > > > > > > +	switch (mask) {
> > > > > > > > > +	case IIO_CHAN_INFO_RAW:
> > > > > > > > > +		hid_sensor_power_state(&hg_group-    
> > > > > > > > > >common_attributes,    
> > > > > > > > > true);
> > > > > > > > > +		report_id = hg_state->hinge.report_id;
> > > > > > > > > +		min = hg_state->hinge.logical_minimum;
> > > > > > > > > +		if (report_id < 0) {
> > > > > > > > > +			*val = 0;
> > > > > > > > > +			hid_sensor_power_state(&hg_group-      
> > > > > > > > > > common_attributes,      
> > > > > > > > > +					       false);
> > > > > > > > > +			return -EINVAL;
> > > > > > > > > +		}
> > > > > > > > > +
> > > > > > > > > +		*val = sensor_hub_input_attr_get_raw_value(
> > > > > > > > > +			hg_group->common_attributes.hsdev,
> > > > > > > > > hsdev-      
> > > > > > > > > > usage,      
> > > > > > > > > +			hg_state->hinge_address, report_id,
> > > > > > > > > SENSOR_HUB_SYNC,
> > > > > > > > > +			min < 0);
> > > > > > > > > +
> > > > > > > > > +		hid_sensor_power_state(&hg_group-    
> > > > > > > > > >common_attributes,    
> > > > > > > > > false);
> > > > > > > > > +		ret_type = IIO_VAL_INT;
> > > > > > > > > +		break;
> > > > > > > > > +	case IIO_CHAN_INFO_SCALE:
> > > > > > > > > +		*val = hg_state->scale_pre_decml;
> > > > > > > > > +		*val2 = hg_state->scale_post_decml;
> > > > > > > > > +		ret_type = hg_state->scale_precision;
> > > > > > > > > +		break;
> > > > > > > > > +	case IIO_CHAN_INFO_OFFSET:
> > > > > > > > > +		*val = hg_state->value_offset;
> > > > > > > > > +		ret_type = IIO_VAL_INT;
> > > > > > > > > +		break;
> > > > > > > > > +	case IIO_CHAN_INFO_SAMP_FREQ:
> > > > > > > > > +		ret_type = hid_sensor_read_samp_freq_value(
> > > > > > > > > +			&hg_group->common_attributes, val,
> > > > > > > > > val2);
> > > > > > > > > +		break;
> > > > > > > > > +	case IIO_CHAN_INFO_HYSTERESIS:
> > > > > > > > > +		ret_type = hid_sensor_read_raw_hyst_value(
> > > > > > > > > +			&hg_group->common_attributes, val,
> > > > > > > > > val2);
> > > > > > > > > +		break;
> > > > > > > > > +	default:
> > > > > > > > > +		ret_type = -EINVAL;
> > > > > > > > > +		break;
> > > > > > > > > +	}
> > > > > > > > > +
> > > > > > > > > +	return ret_type;
> > > > > > > > > +}
> > > > > > > > > +
> > > > > > > > > +/* Channel write_raw handler */
> > > > > > > > > +static int hinge_write_raw(struct iio_dev *indio_dev,
> > > > > > > > > +			   struct iio_chan_spec const *chan,
> > > > > > > > > int val,
> > > > > > > > > int val2,
> > > > > > > > > +			   long mask)
> > > > > > > > > +{
> > > > > > > > > +	int ret;
> > > > > > > > > +
> > > > > > > > > +	switch (mask) {
> > > > > > > > > +	case IIO_CHAN_INFO_SAMP_FREQ:
> > > > > > > > > +		ret = hid_sensor_write_samp_freq_value(
> > > > > > > > > +			&hg_group->common_attributes, val,
> > > > > > > > > val2);
> > > > > > > > > +		break;
> > > > > > > > > +	case IIO_CHAN_INFO_HYSTERESIS:
> > > > > > > > > +		ret = hid_sensor_write_raw_hyst_value(
> > > > > > > > > +			&hg_group->common_attributes, val,
> > > > > > > > > val2);
> > > > > > > > > +
> > > > > > > > > +		break;
> > > > > > > > > +	default:
> > > > > > > > > +		ret = -EINVAL;
> > > > > > > > > +	}
> > > > > > > > > +
> > > > > > > > > +	return ret;
> > > > > > > > > +}
> > > > > > > > > +
> > > > > > > > > +static const struct iio_info hinge_info = {
> > > > > > > > > +	.read_raw = &hinge_read_raw,
> > > > > > > > > +	.write_raw = &hinge_write_raw,
> > > > > > > > > +};
> > > > > > > > > +
> > > > > > > > > +/*
> > > > > > > > > + * Function to push data to buffer;
> > > > > > > > > + * wrapper added for symmetry with other hid-sensor drivers
> > > > > > > > > + */
> > > > > > > > > +static void hid_sensor_push_data(struct iio_dev *indio_dev,
> > > > > > > > > void
> > > > > > > > > *data, int len,      
> > > > > > > > 
> > > > > > > > This doesn't seem to be generic, so don't name it as such.
> > > > > > > >       
> > > > > > > > > +				 int64_t timestamp)
> > > > > > > > > +{
> > > > > > > > > +	iio_push_to_buffers_with_timestamp(indio_dev, data,
> > > > > > > > > timestamp);      
> > > > > > > > I hope that data buffer obeys the various rules needed by (and
> > > > > > > > admittedly
> > > > > > > > not that well documented) iio_push_to_buffers_with_timestamp()
> > > > > > > > 
> > > > > > > > 1. Needs to be 8 byte aligned.
> > > > > > > > 2. Needs to have space for an aligned 8 byte timestamp at the
> > > > > > > > end.
> > > > > > > >       
> > > > > > > > > +}
> > > > > > > > > +
> > > > > > > > > +/*
> > > > > > > > > + * Callback handler to send event after all samples are
> > > > > > > > > received
> > > > > > > > > + * and captured.
> > > > > > > > > + */
> > > > > > > > > +static int hinge_proc_event(struct hid_sensor_hub_device
> > > > > > > > > *hsdev,
> > > > > > > > > +			    unsigned int usage_id, void *priv)
> > > > > > > > > +{
> > > > > > > > > +	int i;
> > > > > > > > > +
> > > > > > > > > +	for (i = 0; i < IIO_DEV_NUM; ++i) {      
> > > > > > > > If we push for all sensors together, better to have
> > > > > > > > this as a single iio_device with 3 channels.
> > > > > > > > 
> > > > > > > > Use the channel labels (just added to IIO) to identify which is
> > > > > > > > which.
> > > > > > > >       
> > > > > > > > > +		struct hinge_state *hg_state;
> > > > > > > > > +		struct iio_dev *indio_dev;
> > > > > > > > > +
> > > > > > > > > +		hg_state = hg_group->hg_states[i];
> > > > > > > > > +		indio_dev = hg_state->indio_dev;
> > > > > > > > > +
> > > > > > > > > +		dev_dbg(&indio_dev->dev, "%s timestamp:%llu
> > > > > > > > > scan_bytes:%d\n",
> > > > > > > > > +			__func__, hg_state->timestamp,
> > > > > > > > > indio_dev-      
> > > > > > > > > > scan_bytes);      
> > > > > > > > > +
> > > > > > > > > +		if (!hg_state->timestamp)
> > > > > > > > > +			hg_state->timestamp =
> > > > > > > > > iio_get_time_ns(indio_dev);
> > > > > > > > > +
> > > > > > > > > +		hid_sensor_push_data(indio_dev, hg_state-    
> > > > > > > > > >hinge_val,    
> > > > > > > > > +				     sizeof(hg_state-    
> > > > > > > > > >hinge_val),    
> > > > > > > > > +				     hg_state->timestamp);
> > > > > > > > > +
> > > > > > > > > +		hg_state->timestamp = 0;
> > > > > > > > > +	}
> > > > > > > > > +
> > > > > > > > > +	return 0;
> > > > > > > > > +}
> > > > > > > > > +
> > > > > > > > > +/* Capture samples in local storage */
> > > > > > > > > +static int hinge_capture_sample(struct hid_sensor_hub_device
> > > > > > > > > *hsdev,
> > > > > > > > > +				unsigned int usage_id, size_t
> > > > > > > > > raw_len,
> > > > > > > > > +				char *raw_data, void *priv)
> > > > > > > > > +{
> > > > > > > > > +	struct hinge_state *hg_state;
> > > > > > > > > +	int offset;
> > > > > > > > > +	int ret = -EINVAL;
> > > > > > > > > +	int i;
> > > > > > > > > +
> > > > > > > > > +	if (usage_id == HID_USAGE_SENSOR_TIME_TIMESTAMP) {
> > > > > > > > > +		for (i = 0; i < IIO_DEV_NUM; i++)
> > > > > > > > > +			hg_group->hg_states[i]->timestamp =      
> > > > > > > > 
> > > > > > > > This rather implies all the data is captured together... If so
> > > > > > > > single
> > > > > > > > iio_device may make more sense.
> > > > > > > >       
> > > > > > > > > +				hid_sensor_convert_timestamp(
> > > > > > > > > +					&hg_group-    
> > > > > > > > > >common_attributes,    
> > > > > > > > > +					*(int64_t *)raw_data);
> > > > > > > > > +		return 0;
> > > > > > > > > +	}
> > > > > > > > > +
> > > > > > > > > +	switch (usage_id) {
> > > > > > > > > +	case HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_1:
> > > > > > > > > +	case HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_2:
> > > > > > > > > +	case HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_3:
> > > > > > > > > +		offset = usage_id -
> > > > > > > > > HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_1;
> > > > > > > > > +		hg_state = hg_group->hg_states[offset];
> > > > > > > > > +		hg_state->hinge_val[0] = *(u32 *)raw_data;
> > > > > > > > > +		ret = 0;      
> > > > > > > > 
> > > > > > > > 		return 0;
> > > > > > > >       
> > > > > > > > > +		break;
> > > > > > > > > +	default:      
> > > > > > > > 		return -EINVAL;      
> > > > > > > > > +		break;
> > > > > > > > > +	}
> > > > > > > > > +
> > > > > > > > > +	return ret;
> > > > > > > > > +}
> > > > > > > > > +
> > > > > > > > > +/* Parse report which is specific to an usage id */
> > > > > > > > > +static int hinge_parse_report(struct platform_device *pdev,
> > > > > > > > > +			      struct hid_sensor_hub_device
> > > > > > > > > *hsdev,
> > > > > > > > > +			      unsigned int usage_id, unsigned
> > > > > > > > > int
> > > > > > > > > attr_usage_id,
> > > > > > > > > +			      struct hinge_state *st)
> > > > > > > > > +{
> > > > > > > > > +	int ret;
> > > > > > > > > +
> > > > > > > > > +	ret = sensor_hub_input_get_attribute_info(
> > > > > > > > > +		hsdev, HID_INPUT_REPORT, usage_id,
> > > > > > > > > attr_usage_id, &st-      
> > > > > > > > > > hinge);      
> > > > > > > > > +	if (ret < 0)
> > > > > > > > > +		return ret;
> > > > > > > > > +
> > > > > > > > > +	st->hinge_address = attr_usage_id;
> > > > > > > > > +	st->scale_precision =
> > > > > > > > > +		hid_sensor_format_scale(HID_USAGE_SENSOR_HINGE,
> > > > > > > > > &st-      
> > > > > > > > > > hinge,      
> > > > > > > > > +					&st->scale_pre_decml,
> > > > > > > > > +					&st->scale_post_decml);
> > > > > > > > > +
> > > > > > > > > +	/* Set Sensitivity field ids, when there is no
> > > > > > > > > individual
> > > > > > > > > modifier */
> > > > > > > > > +	if (hg_group->common_attributes.sensitivity.index < 0)
> > > > > > > > > {
> > > > > > > > > +		sensor_hub_input_get_attribute_info(
> > > > > > > > > +			hsdev, HID_FEATURE_REPORT, usage_id,
> > > > > > > > > +			HID_USAGE_SENSOR_DATA_MOD_CHANGE_SENSIT
> > > > > > > > > IVITY_AB
> > > > > > > > > S |
> > > > > > > > > +				HID_USAGE_SENSOR_DATA_FIELD_CUS
> > > > > > > > > TOM_VALU
> > > > > > > > > E_1,
> > > > > > > > > +			&hg_group-    
> > > > > > > > > >common_attributes.sensitivity);    
> > > > > > > > > +		dev_dbg(&pdev->dev, "Sensitivity index:report
> > > > > > > > > %d:%d\n",
> > > > > > > > > +			hg_group-    
> > > > > > > > > >common_attributes.sensitivity.index,    
> > > > > > > > > +			hg_group-      
> > > > > > > > > > common_attributes.sensitivity.report_id);      
> > > > > > > > > +	}
> > > > > > > > > +
> > > > > > > > > +	return ret;
> > > > > > > > > +}
> > > > > > > > > +
> > > > > > > > > +/* Function to initialize the processing for usage id */
> > > > > > > > > +static int hinge_add_iio_device(struct platform_device
> > > > > > > > > *pdev,
> > > > > > > > > int
> > > > > > > > > index,
> > > > > > > > > +				const char *name, struct
> > > > > > > > > hinge_state
> > > > > > > > > **st)
> > > > > > > > > +{
> > > > > > > > > +	struct hid_sensor_hub_device *hsdev = pdev-    
> > > > > > > > > >dev.platform_data;    
> > > > > > > > > +	struct hinge_state *hg_state;
> > > > > > > > > +	struct iio_dev *indio_dev;
> > > > > > > > > +	int ret;
> > > > > > > > > +
> > > > > > > > > +	indio_dev =
> > > > > > > > > +		devm_iio_device_alloc(&pdev->dev, sizeof(struct
> > > > > > > > > hinge_state));      
> > > > > > > > 
> > > > > > > > sizeof (*hg_state) preferred.
> > > > > > > >       
> > > > > > > > > +	if (indio_dev == NULL)
> > > > > > > > > +		return -ENOMEM;
> > > > > > > > > +
> > > > > > > > > +	hg_state = iio_priv(indio_dev);
> > > > > > > > > +	hg_state->indio_dev = indio_dev;
> > > > > > > > > +
> > > > > > > > > +	indio_dev->num_channels = ARRAY_SIZE(hinge_channels);
> > > > > > > > > +	indio_dev->channels =
> > > > > > > > > +		kmemdup(hinge_channels, sizeof(hinge_channels),
> > > > > > > > > GFP_KERNEL);      
> > > > > > > > 
> > > > > > > > I don't immediately see anything that is modifying channels. As
> > > > > > > > such
> > > > > > > > you
> > > > > > > > should be able have it shared by all the instances.
> > > > > > > >       
> > > > > > > > > +	if (!indio_dev->channels)
> > > > > > > > > +		return -ENOMEM;
> > > > > > > > > +
> > > > > > > > > +	ret = hinge_parse_report(
> > > > > > > > > +		pdev, hsdev, hsdev->usage,
> > > > > > > > > +		HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_1 +
> > > > > > > > > index,
> > > > > > > > > hg_state);
> > > > > > > > > +	if (ret) {
> > > > > > > > > +		dev_err(&pdev->dev, "failed to setup
> > > > > > > > > attributes\n");
> > > > > > > > > +		goto error_free_dev_mem;
> > > > > > > > > +	}
> > > > > > > > > +
> > > > > > > > > +	indio_dev->dev.parent = &pdev->dev;
> > > > > > > > > +	indio_dev->info = &hinge_info;
> > > > > > > > > +	indio_dev->name = name;
> > > > > > > > > +	indio_dev->modes = INDIO_DIRECT_MODE;
> > > > > > > > > +
> > > > > > > > > +	ret = hid_sensor_setup_trigger(indio_dev, name,
> > > > > > > > > +				       &hg_group-    
> > > > > > > > > >common_attributes);    
> > > > > > > > > +	if (ret < 0) {
> > > > > > > > > +		dev_err(&pdev->dev, "trigger setup failed\n");
> > > > > > > > > +		goto error_free_dev_mem;
> > > > > > > > > +	}
> > > > > > > > > +
> > > > > > > > > +	ret = iio_device_register(indio_dev);
> > > > > > > > > +	if (ret) {
> > > > > > > > > +		dev_err(&pdev->dev, "device register
> > > > > > > > > failed\n");
> > > > > > > > > +		goto error_remove_trigger;
> > > > > > > > > +	}
> > > > > > > > > +
> > > > > > > > > +	*st = hg_state;
> > > > > > > > > +
> > > > > > > > > +	return ret;
> > > > > > > > > +
> > > > > > > > > +error_remove_trigger:
> > > > > > > > > +	hid_sensor_remove_trigger(indio_dev, &hg_group-      
> > > > > > > > > > common_attributes);      
> > > > > > > > > +error_free_dev_mem:
> > > > > > > > > +	kfree(indio_dev->channels);
> > > > > > > > > +	return ret;
> > > > > > > > > +}
> > > > > > > > > +
> > > > > > > > > +/* Function to deinitialize the processing for usage id */
> > > > > > > > > +static int hinge_remove_iio_device(struct platform_device
> > > > > > > > > *pdev,
> > > > > > > > > int index)
> > > > > > > > > +{
> > > > > > > > > +	struct hinge_state *hg_state = hg_group-    
> > > > > > > > > >hg_states[index];    
> > > > > > > > > +	struct iio_dev *indio_dev = hg_state->indio_dev;
> > > > > > > > > +
> > > > > > > > > +	iio_device_unregister(indio_dev);
> > > > > > > > > +	hid_sensor_remove_trigger(indio_dev, &hg_group-      
> > > > > > > > > > common_attributes);      
> > > > > > > > > +	kfree(indio_dev->channels);
> > > > > > > > > +
> > > > > > > > > +	return 0;
> > > > > > > > > +}
> > > > > > > > > +
> > > > > > > > > +static int hid_hinge_probe(struct platform_device *pdev)
> > > > > > > > > +{
> > > > > > > > > +	struct hinge_state *hg_state;
> > > > > > > > > +	struct hid_sensor_hub_device *hsdev = pdev-    
> > > > > > > > > >dev.platform_data;    
> > > > > > > > > +	static const char *const names[] = { "hinge", "screen",
> > > > > > > > > "keyboard" };
> > > > > > > > > +	int ret;
> > > > > > > > > +	int i;
> > > > > > > > > +
> > > > > > > > > +	hg_group = devm_kzalloc(&pdev->dev, sizeof(struct
> > > > > > > > > hinge_group),
> > > > > > > > > +				GFP_KERNEL);      
> > > > > > > > 
> > > > > > > > As mentioned above, I'd really not expect to see a global like
> > > > > > > > this.
> > > > > > > > Technically nothing stops there being more than one instance of
> > > > > > > > this
> > > > > > > > device on a platform (even if that would be a bit odd) + it's
> > > > > > > > almost
> > > > > > > > always cleaner to not use a global in the first place.
> > > > > > > >       
> > > > > > > > > +	if (!hg_group)
> > > > > > > > > +		return -ENOMEM;
> > > > > > > > > +
> > > > > > > > > +	hg_group->common_attributes.hsdev = hsdev;
> > > > > > > > > +	hg_group->common_attributes.pdev = pdev;
> > > > > > > > > +
> > > > > > > > > +	ret = hid_sensor_parse_common_attributes(hsdev, hsdev-    
> > > > > > > > > >usage,    
> > > > > > > > > +						 &hg_group-      
> > > > > > > > > > common_attributes);      
> > > > > > > > > +	if (ret) {
> > > > > > > > > +		dev_err(&pdev->dev, "failed to setup common
> > > > > > > > > attributes\n");
> > > > > > > > > +		return ret;
> > > > > > > > > +	}
> > > > > > > > > +
> > > > > > > > > +	atomic_set(&hg_group->common_attributes.data_ready, 0);
> > > > > > > > > +	for (i = 0; i < IIO_DEV_NUM; i++) {
> > > > > > > > > +		ret = hinge_add_iio_device(pdev, i, names[i],
> > > > > > > > > &hg_state);
> > > > > > > > > +		if (ret)
> > > > > > > > > +			goto err_probe;
> > > > > > > > > +
> > > > > > > > > +		hg_group->hg_states[i] = hg_state;
> > > > > > > > > +	}
> > > > > > > > > +
> > > > > > > > > +	/* use the first iio device to do the PM */
> > > > > > > > > +	platform_set_drvdata(pdev, hg_group->hg_states[0]-    
> > > > > > > > > >indio_dev);    
> > > > > > > > > +
> > > > > > > > > +	hg_group->callbacks.send_event = hinge_proc_event;
> > > > > > > > > +	hg_group->callbacks.capture_sample =
> > > > > > > > > hinge_capture_sample;
> > > > > > > > > +	hg_group->callbacks.pdev = pdev;
> > > > > > > > > +	ret = sensor_hub_register_callback(hsdev, hsdev->usage,
> > > > > > > > > +					   &hg_group-    
> > > > > > > > > >callbacks);    
> > > > > > > > > +	if (ret < 0)
> > > > > > > > > +		dev_err(&pdev->dev, "callback reg failed\n");
> > > > > > > > > +
> > > > > > > > > +	return ret;
> > > > > > > > > +
> > > > > > > > > +err_probe:
> > > > > > > > > +	for (i--; i >= 0; i--)
> > > > > > > > > +		hinge_remove_iio_device(pdev, i);
> > > > > > > > > +
> > > > > > > > > +	return ret;
> > > > > > > > > +}
> > > > > > > > > +
> > > > > > > > > +/* Function to deinitialize the processing for usage id */
> > > > > > > > > +static int hid_hinge_remove(struct platform_device *pdev)
> > > > > > > > > +{
> > > > > > > > > +	struct hid_sensor_hub_device *hsdev = pdev-    
> > > > > > > > > >dev.platform_data;    
> > > > > > > > > +	int i;
> > > > > > > > > +
> > > > > > > > > +	sensor_hub_remove_callback(hsdev, hsdev->usage);
> > > > > > > > > +
> > > > > > > > > +	for (i = 0; i < IIO_DEV_NUM; i++)
> > > > > > > > > +		hinge_remove_iio_device(pdev, i);
> > > > > > > > > +
> > > > > > > > > +	return 0;
> > > > > > > > > +}
> > > > > > > > > +
> > > > > > > > > +static const struct platform_device_id hid_hinge_ids[] = {
> > > > > > > > > +	{
> > > > > > > > > +		/* Format: HID-SENSOR-INT-
> > > > > > > > > usage_id_in_hex_lowercase */
> > > > > > > > > +		.name = "HID-SENSOR-INT-020b",
> > > > > > > > > +	},
> > > > > > > > > +	{ /* sentinel */ }
> > > > > > > > > +};
> > > > > > > > > +MODULE_DEVICE_TABLE(platform, hid_hinge_ids);
> > > > > > > > > +
> > > > > > > > > +static struct platform_driver hid_hinge_platform_driver = {
> > > > > > > > > +	.id_table = hid_hinge_ids,
> > > > > > > > > +	.driver = {
> > > > > > > > > +		.name	= KBUILD_MODNAME,
> > > > > > > > > +		.pm	= &hid_sensor_pm_ops,
> > > > > > > > > +	},
> > > > > > > > > +	.probe		= hid_hinge_probe,
> > > > > > > > > +	.remove		= hid_hinge_remove,
> > > > > > > > > +};
> > > > > > > > > +module_platform_driver(hid_hinge_platform_driver);
> > > > > > > > > +
> > > > > > > > > +MODULE_DESCRIPTION("HID Sensor Custom Hinge");
> > > > > > > > > +MODULE_AUTHOR("Ye Xiang <xiang.ye@intel.com>");
> > > > > > > > > +MODULE_LICENSE("GPL");      
> > >   
>

[v2,4/4] iio: hid-sensors: Add hinge sensor driver

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