diff mbox series

[V4,2/2] media: i2c: Add DW9768 VCM driver

Message ID 20200330123634.363-3-dongchun.zhu@mediatek.com (mailing list archive)
State New, archived
Headers show
Series media: i2c: add support for DW9768 VCM driver | expand

Commit Message

Dongchun Zhu March 30, 2020, 12:36 p.m. UTC 
This patch adds a V4L2 sub-device driver for DW9768 voice coil moter,
providing control to set the desired focus via I2C serial interface.

Signed-off-by: Dongchun Zhu <dongchun.zhu@mediatek.com>
---
 MAINTAINERS                |   1 +
 drivers/media/i2c/Kconfig  |  11 ++
 drivers/media/i2c/Makefile |   1 +
 drivers/media/i2c/dw9768.c | 432 +++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 445 insertions(+)
 create mode 100644 drivers/media/i2c/dw9768.c

Comments

Andy Shevchenko March 30, 2020, 1:57 p.m. UTC | #1 
On Mon, Mar 30, 2020 at 08:36:34PM +0800, Dongchun Zhu wrote:
> This patch adds a V4L2 sub-device driver for DW9768 voice coil moter,
> providing control to set the desired focus via I2C serial interface.

...

> +static const struct dev_pm_ops dw9768_pm_ops = {
> +	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
> +				pm_runtime_force_resume)
> +	SET_RUNTIME_PM_OPS(dw9768_runtime_suspend, dw9768_runtime_resume, NULL)
> +};
> +
> +static struct i2c_driver dw9768_i2c_driver = {
> +	.driver = {
> +		.name = DW9768_NAME,

> +		.pm = IS_ENABLED(CONFIG_PM) ? &dw9768_pm_ops : NULL,

What is this conditional for?

> +		.of_match_table = dw9768_of_table,
> +	},
> +	.probe_new  = dw9768_probe,
> +	.remove = dw9768_remove,
> +};

> +

Extra blank line.

> +module_i2c_driver(dw9768_i2c_driver);
Dongchun Zhu March 31, 2020, 2:16 a.m. UTC | #2 
Hi Andy,

Thanks for the review.

On Mon, 2020-03-30 at 16:57 +0300, Andy Shevchenko wrote:
> On Mon, Mar 30, 2020 at 08:36:34PM +0800, Dongchun Zhu wrote:
> > This patch adds a V4L2 sub-device driver for DW9768 voice coil moter,
> > providing control to set the desired focus via I2C serial interface.
> 
> ...
> 
> > +static const struct dev_pm_ops dw9768_pm_ops = {
> > +	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
> > +				pm_runtime_force_resume)
> > +	SET_RUNTIME_PM_OPS(dw9768_runtime_suspend, dw9768_runtime_resume, NULL)
> > +};
> > +
> > +static struct i2c_driver dw9768_i2c_driver = {
> > +	.driver = {
> > +		.name = DW9768_NAME,
> 
> > +		.pm = IS_ENABLED(CONFIG_PM) ? &dw9768_pm_ops : NULL,
> 
> What is this conditional for?
> 

For the dw9768_pm_ops, here my idea is to use an IS_ENABLED() check to
avoid defining the structure when CONFIG_PM is not set.

> > +		.of_match_table = dw9768_of_table,
> > +	},
> > +	.probe_new  = dw9768_probe,
> > +	.remove = dw9768_remove,
> > +};
> 
> > +
> 
> Extra blank line.
> 

Weird, most V4L2 driver(I2C client) seems to keep this blank line.
Sakari, is it still the case or am I mistaken?

> > +module_i2c_driver(dw9768_i2c_driver);
>
Andy Shevchenko March 31, 2020, 10:14 a.m. UTC | #3 
On Tue, Mar 31, 2020 at 10:16:20AM +0800, Dongchun Zhu wrote:
> On Mon, 2020-03-30 at 16:57 +0300, Andy Shevchenko wrote:
> > On Mon, Mar 30, 2020 at 08:36:34PM +0800, Dongchun Zhu wrote:
> > > This patch adds a V4L2 sub-device driver for DW9768 voice coil moter,
> > > providing control to set the desired focus via I2C serial interface.
> > 
> > ...
> > 
> > > +static const struct dev_pm_ops dw9768_pm_ops = {
> > > +	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
> > > +				pm_runtime_force_resume)
> > > +	SET_RUNTIME_PM_OPS(dw9768_runtime_suspend, dw9768_runtime_resume, NULL)
> > > +};
> > > +
> > > +static struct i2c_driver dw9768_i2c_driver = {
> > > +	.driver = {
> > > +		.name = DW9768_NAME,
> > 
> > > +		.pm = IS_ENABLED(CONFIG_PM) ? &dw9768_pm_ops : NULL,
> > 
> > What is this conditional for?
> > 
> 
> For the dw9768_pm_ops, here my idea is to use an IS_ENABLED() check to
> avoid defining the structure when CONFIG_PM is not set.

Have you looked at the implementation of SET_SYSTEM_SLEEP_OPS() and another one?

Have you tried to actually compile with !CONFIG_PM? In your case the warning
should be issued.
Sakari Ailus April 2, 2020, 12:32 p.m. UTC | #4 
Hi Dongchun,

On Mon, Mar 30, 2020 at 08:36:34PM +0800, Dongchun Zhu wrote:
> This patch adds a V4L2 sub-device driver for DW9768 voice coil moter,
> providing control to set the desired focus via I2C serial interface.
> 
> Signed-off-by: Dongchun Zhu <dongchun.zhu@mediatek.com>
> ---
>  MAINTAINERS                |   1 +
>  drivers/media/i2c/Kconfig  |  11 ++
>  drivers/media/i2c/Makefile |   1 +
>  drivers/media/i2c/dw9768.c | 432 +++++++++++++++++++++++++++++++++++++++++++++
>  4 files changed, 445 insertions(+)
>  create mode 100644 drivers/media/i2c/dw9768.c
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 5e124d2..e007a1b 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -5140,6 +5140,7 @@ L:	linux-media@vger.kernel.org
>  S:	Maintained
>  T:	git git://linuxtv.org/media_tree.git
>  F:	Documentation/devicetree/bindings/media/i2c/dongwoon,dw9768.yaml
> +F:	drivers/media/i2c/dw9768.c
>  
>  DONGWOON DW9807 LENS VOICE COIL DRIVER
>  M:	Sakari Ailus <sakari.ailus@linux.intel.com>
> diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
> index c68e002..b759d3d 100644
> --- a/drivers/media/i2c/Kconfig
> +++ b/drivers/media/i2c/Kconfig
> @@ -1024,6 +1024,17 @@ config VIDEO_DW9714
>  	  capability. This is designed for linear control of
>  	  voice coil motors, controlled via I2C serial interface.
>  
> +config VIDEO_DW9768
> +	tristate "DW9768 lens voice coil support"
> +	depends on I2C && VIDEO_V4L2 && MEDIA_CONTROLLER
> +	depends on VIDEO_V4L2_SUBDEV_API
> +	depends on PM
> +	help
> +	  This is a driver for the DW9768 camera lens voice coil.
> +	  DW9768 is a 10 bit DAC with 100mA output current sink
> +	  capability. This is designed for linear control of
> +	  voice coil motors, controlled via I2C serial interface.
> +
>  config VIDEO_DW9807_VCM
>  	tristate "DW9807 lens voice coil support"
>  	depends on I2C && VIDEO_V4L2 && MEDIA_CONTROLLER
> diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
> index c147bb9..ec94434 100644
> --- a/drivers/media/i2c/Makefile
> +++ b/drivers/media/i2c/Makefile
> @@ -24,6 +24,7 @@ obj-$(CONFIG_VIDEO_SAA6752HS) += saa6752hs.o
>  obj-$(CONFIG_VIDEO_AD5820)  += ad5820.o
>  obj-$(CONFIG_VIDEO_AK7375)  += ak7375.o
>  obj-$(CONFIG_VIDEO_DW9714)  += dw9714.o
> +obj-$(CONFIG_VIDEO_DW9768)  += dw9768.o
>  obj-$(CONFIG_VIDEO_DW9807_VCM)  += dw9807-vcm.o
>  obj-$(CONFIG_VIDEO_ADV7170) += adv7170.o
>  obj-$(CONFIG_VIDEO_ADV7175) += adv7175.o
> diff --git a/drivers/media/i2c/dw9768.c b/drivers/media/i2c/dw9768.c
> new file mode 100644
> index 0000000..f63afa1
> --- /dev/null
> +++ b/drivers/media/i2c/dw9768.c
> @@ -0,0 +1,432 @@
> +// SPDX-License-Identifier: GPL-2.0
> +// Copyright (c) 2020 MediaTek Inc.
> +
> +#include <linux/delay.h>
> +#include <linux/i2c.h>
> +#include <linux/module.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/regulator/consumer.h>
> +#include <media/v4l2-async.h>
> +#include <media/v4l2-ctrls.h>
> +#include <media/v4l2-device.h>
> +#include <media/v4l2-subdev.h>
> +
> +#define DW9768_NAME				"dw9768"
> +#define DW9768_MAX_FOCUS_POS			(1024 - 1)
> +/*
> + * This sets the minimum granularity for the focus positions.
> + * A value of 1 gives maximum accuracy for a desired focus position
> + */
> +#define DW9768_FOCUS_STEPS			1
> +
> +/*
> + * Ring control and Power control register
> + * Bit[1] RING_EN
> + * 0: Direct mode
> + * 1: AAC mode (ringing control mode)
> + * Bit[0] PD
> + * 0: Normal operation mode
> + * 1: Power down mode
> + * DW9768 requires waiting time of Topr after PD reset takes place.
> + */
> +#define DW9768_RING_PD_CONTROL_REG		0x02
> +#define DW9768_PD_MODE_OFF			0x00
> +#define DW9768_PD_MODE_EN			BIT(0)
> +#define DW9768_AAC_MODE_EN			BIT(1)
> +
> +/*
> + * DW9768 separates two registers to control the VCM position.
> + * One for MSB value, another is LSB value.
> + * DAC_MSB: D[9:8] (ADD: 0x03)
> + * DAC_LSB: D[7:0] (ADD: 0x04)
> + * D[9:0] DAC data input: positive output current = D[9:0] / 1023 * 100[mA]
> + */
> +#define DW9768_MSB_ADDR				0x03
> +#define DW9768_LSB_ADDR				0x04
> +#define DW9768_STATUS_ADDR			0x05
> +
> +/*
> + * AAC mode control & prescale register
> + * Bit[7:5] Namely AC[2:0], decide the VCM mode and operation time.
> + * 000 Direct(default)
> + * 001 AAC2 0.48xTvib
> + * 010 AAC3 0.70xTvib
> + * 011 AAC4 0.75xTvib
> + * 100 Reserved
> + * 101 AAC8 1.13xTvib
> + * 110 Reserved
> + * 111 Reserved
> + * Bit[2:0] Namely PRESC[2:0], set the internal clock dividing rate as follow.
> + * 000 2
> + * 001 1(default)
> + * 010 1/2
> + * 011 1/4
> + * 100 8
> + * 101 4
> + * 110 Reserved
> + * 111 Reserved
> + */
> +#define DW9768_AAC_PRESC_REG			0x06
> +#define DW9768_AAC3_SELECT_DIVIDING_RATE_1	0x41
> +
> +/*
> + * VCM period of vibration register
> + * Bit[5:0] Defined as VCM rising periodic time (Tvib) together with PRESC[2:0]
> + * Tvib = (6.3ms + AACT[5:0] * 0.1ms) * Dividing Rate
> + * Dividing Rate is the internal clock dividing rate that is defined at
> + * PRESCALE register (ADD: 0x06)
> + */
> +#define DW9768_AAC_TIME_REG			0x07
> +#define DW9768_AACT_CNT				0x39
> +
> +/*
> + * DW9768 requires waiting time (delay time) of t_OPR after power-up,
> + * or in the case of PD reset taking place.
> + */
> +#define DW9768_T_OPR_US				1000
> +
> +/*
> + * This acts as the minimum granularity of lens movement.
> + * Keep this value power of 2, so the control steps can be
> + * uniformly adjusted for gradual lens movement, with desired
> + * number of control steps.
> + */
> +#define DW9768_MOVE_STEPS			16
> +
> +/*
> + * DW9768_AAC_PRESC_REG & DW9768_AAC_TIME_REG determine VCM operation time.
> + * If DW9768_AAC_PRESC_REG is 0x41, and DW9768_AAC_TIME_REG is 0x39, VCM mode
> + * would be AAC3, Operation Time would be 0.70xTvib, that is 8.40ms.
> + */
> +#define DW9768_MOVE_DELAY_US			8400
> +#define DW9768_STABLE_TIME_US			20000
> +
> +static const char * const dw9768_supply_names[] = {
> +	"vin",	/* I2C I/O interface power */
> +	"vdd",	/* VCM power */
> +};
> +
> +/* dw9768 device structure */
> +struct dw9768 {
> +	struct regulator_bulk_data supplies[ARRAY_SIZE(dw9768_supply_names)];
> +	struct v4l2_ctrl_handler ctrls;
> +	struct v4l2_ctrl *focus;
> +	struct v4l2_subdev sd;
> +};
> +
> +static inline struct dw9768 *to_dw9768(struct v4l2_ctrl *ctrl)
> +{
> +	return container_of(ctrl->handler, struct dw9768, ctrls);
> +}
> +
> +static inline struct dw9768 *sd_to_dw9768(struct v4l2_subdev *subdev)
> +{
> +	return container_of(subdev, struct dw9768, sd);
> +}
> +
> +struct regval_list {
> +	u8 reg_num;
> +	u8 value;
> +};
> +
> +static const struct regval_list dw9768_init_regs[] = {
> +	{DW9768_RING_PD_CONTROL_REG, DW9768_AAC_MODE_EN},
> +	{DW9768_AAC_PRESC_REG, DW9768_AAC3_SELECT_DIVIDING_RATE_1},
> +	{DW9768_AAC_TIME_REG, DW9768_AACT_CNT},

Apologies for missing to follow the earlier discussion related to this.

I wonder if these values are specific to a given lens or a module.
Presumably so, as they're changed from the defaults.

In that case I'd put them to DT.

> +};
> +
> +static int dw9768_write_array(struct dw9768 *dw9768,
> +			      const struct regval_list *vals, size_t len)
> +{
> +	struct i2c_client *client = v4l2_get_subdevdata(&dw9768->sd);
> +	unsigned int i;
> +	int ret;
> +
> +	for (i = 0; i < len; i++) {
> +		ret = i2c_smbus_write_byte_data(client, vals[i].reg_num,
> +						vals[i].value);
> +		if (ret < 0)
> +			return ret;
> +	}
> +	return 0;
> +}
> +
> +static int dw9768_set_dac(struct dw9768 *dw9768, u16 val)
> +{
> +	struct i2c_client *client = v4l2_get_subdevdata(&dw9768->sd);
> +
> +	/* Write VCM position to registers */
> +	return i2c_smbus_write_word_swapped(client, DW9768_MSB_ADDR, val);
> +}
> +
> +static int dw9768_init(struct dw9768 *dw9768)
> +{
> +	struct i2c_client *client = v4l2_get_subdevdata(&dw9768->sd);
> +	int ret, val;
> +
> +	/* Reset DW9768_RING_PD_CONTROL_REG to default status 0x00 */
> +	ret = i2c_smbus_write_byte_data(client, DW9768_RING_PD_CONTROL_REG,
> +					DW9768_PD_MODE_OFF);
> +	if (ret < 0)
> +		return ret;
> +
> +	/*
> +	 * DW9769 requires waiting delay time of t_OPR
> +	 * after PD reset takes place.
> +	 */
> +	usleep_range(DW9768_T_OPR_US, DW9768_T_OPR_US + 100);
> +
> +	ret = dw9768_write_array(dw9768, dw9768_init_regs,
> +				 ARRAY_SIZE(dw9768_init_regs));
> +	if (ret)
> +		return ret;
> +
> +	for (val = dw9768->focus->val % DW9768_MOVE_STEPS;
> +	     val <= dw9768->focus->val;
> +	     val += DW9768_MOVE_STEPS) {
> +		ret = dw9768_set_dac(dw9768, val);
> +		if (ret) {
> +			dev_err(&client->dev, "I2C write fail: %d", ret);
> +			return ret;
> +		}
> +		usleep_range(DW9768_MOVE_DELAY_US, DW9768_MOVE_DELAY_US + 1000);
> +	}
> +
> +	return 0;
> +}
> +
> +static int dw9768_release(struct dw9768 *dw9768)
> +{
> +	struct i2c_client *client = v4l2_get_subdevdata(&dw9768->sd);
> +	int ret, val;
> +
> +	val = round_down(dw9768->focus->val, DW9768_MOVE_STEPS);
> +	for ( ; val >= 0; val -= DW9768_MOVE_STEPS) {
> +		ret = dw9768_set_dac(dw9768, val);
> +		if (ret) {
> +			dev_err(&client->dev, "I2C write fail: %d", ret);
> +			return ret;
> +		}
> +		usleep_range(DW9768_MOVE_DELAY_US, DW9768_MOVE_DELAY_US + 1000);
> +	}
> +
> +	/*
> +	 * Wait for the motor to stabilize after the last movement
> +	 * to prevent the motor from shaking.
> +	 */
> +	usleep_range(DW9768_STABLE_TIME_US - DW9768_MOVE_DELAY_US,
> +		     DW9768_STABLE_TIME_US - DW9768_MOVE_DELAY_US + 1000);
> +
> +	ret = i2c_smbus_write_byte_data(client, DW9768_RING_PD_CONTROL_REG,
> +					DW9768_PD_MODE_EN);
> +	if (ret < 0)
> +		return ret;
> +
> +	/*
> +	 * DW9769 requires waiting delay time of t_OPR
> +	 * after PD reset takes place.
> +	 */
> +	usleep_range(DW9768_T_OPR_US, DW9768_T_OPR_US + 100);
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused dw9768_runtime_suspend(struct device *dev)
> +{
> +	struct i2c_client *client = to_i2c_client(dev);
> +	struct v4l2_subdev *sd = i2c_get_clientdata(client);
> +	struct dw9768 *dw9768 = sd_to_dw9768(sd);
> +
> +	dw9768_release(dw9768);
> +	regulator_bulk_disable(ARRAY_SIZE(dw9768_supply_names),
> +			       dw9768->supplies);
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused dw9768_runtime_resume(struct device *dev)
> +{
> +	struct i2c_client *client = to_i2c_client(dev);
> +	struct v4l2_subdev *sd = i2c_get_clientdata(client);
> +	struct dw9768 *dw9768 = sd_to_dw9768(sd);
> +	int ret;
> +
> +	ret = regulator_bulk_enable(ARRAY_SIZE(dw9768_supply_names),
> +				    dw9768->supplies);
> +	if (ret < 0) {
> +		dev_err(dev, "failed to enable regulators\n");
> +		return ret;
> +	}
> +
> +	/*
> +	 * The datasheet refers to t_OPR that needs to be waited before sending
> +	 * I2C commands after power-up.
> +	 */
> +	usleep_range(DW9768_T_OPR_US, DW9768_T_OPR_US + 100);
> +
> +	ret = dw9768_init(dw9768);
> +	if (ret < 0)
> +		goto disable_regulator;
> +
> +	return 0;
> +
> +disable_regulator:
> +	regulator_bulk_disable(ARRAY_SIZE(dw9768_supply_names),
> +			       dw9768->supplies);
> +
> +	return ret;
> +}
> +
> +static int dw9768_set_ctrl(struct v4l2_ctrl *ctrl)
> +{
> +	struct dw9768 *dw9768 = to_dw9768(ctrl);
> +
> +	if (ctrl->id == V4L2_CID_FOCUS_ABSOLUTE)
> +		return dw9768_set_dac(dw9768, ctrl->val);
> +
> +	return 0;
> +}
> +
> +static const struct v4l2_ctrl_ops dw9768_ctrl_ops = {
> +	.s_ctrl = dw9768_set_ctrl,
> +};
> +
> +static int dw9768_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
> +{
> +	int ret;
> +
> +	ret = pm_runtime_get_sync(sd->dev);
> +	if (ret < 0) {
> +		pm_runtime_put_noidle(sd->dev);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static int dw9768_close(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
> +{
> +	pm_runtime_put(sd->dev);
> +
> +	return 0;
> +}
> +
> +static const struct v4l2_subdev_internal_ops dw9768_int_ops = {
> +	.open = dw9768_open,
> +	.close = dw9768_close,
> +};
> +
> +static const struct v4l2_subdev_ops dw9768_ops = { };
> +
> +static int dw9768_init_controls(struct dw9768 *dw9768)
> +{
> +	struct v4l2_ctrl_handler *hdl = &dw9768->ctrls;
> +	const struct v4l2_ctrl_ops *ops = &dw9768_ctrl_ops;
> +
> +	v4l2_ctrl_handler_init(hdl, 1);
> +
> +	dw9768->focus = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FOCUS_ABSOLUTE, 0,
> +					  DW9768_MAX_FOCUS_POS,
> +					  DW9768_FOCUS_STEPS, 0);
> +
> +	if (hdl->error)
> +		return hdl->error;
> +
> +	dw9768->sd.ctrl_handler = hdl;
> +
> +	return 0;
> +}
> +
> +static int dw9768_probe(struct i2c_client *client)
> +{
> +	struct device *dev = &client->dev;
> +	struct dw9768 *dw9768;
> +	unsigned int i;
> +	int ret;
> +
> +	dw9768 = devm_kzalloc(dev, sizeof(*dw9768), GFP_KERNEL);
> +	if (!dw9768)
> +		return -ENOMEM;
> +
> +	v4l2_i2c_subdev_init(&dw9768->sd, client, &dw9768_ops);
> +
> +	for (i = 0; i < ARRAY_SIZE(dw9768_supply_names); i++)
> +		dw9768->supplies[i].supply = dw9768_supply_names[i];
> +
> +	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(dw9768_supply_names),
> +				      dw9768->supplies);
> +	if (ret) {
> +		dev_err(dev, "failed to get regulators\n");
> +		return ret;
> +	}
> +
> +	ret = dw9768_init_controls(dw9768);
> +	if (ret)
> +		goto entity_cleanup;
> +
> +	dw9768->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> +	dw9768->sd.internal_ops = &dw9768_int_ops;
> +
> +	ret = media_entity_pads_init(&dw9768->sd.entity, 0, NULL);
> +	if (ret < 0)
> +		goto entity_cleanup;
> +
> +	dw9768->sd.entity.function = MEDIA_ENT_F_LENS;
> +
> +	ret = v4l2_async_register_subdev(&dw9768->sd);
> +	if (ret < 0)
> +		goto entity_cleanup;
> +
> +	pm_runtime_enable(dev);

Note that here, the device node may be already created before runtime PM is
enabled.

Could you reverse order of enabling runtime PM and registering the async
subdev to fix that?

> +
> +	return 0;
> +
> +entity_cleanup:
> +	v4l2_ctrl_handler_free(&dw9768->ctrls);
> +	media_entity_cleanup(&dw9768->sd.entity);
> +	return ret;
> +}
> +
> +static int dw9768_remove(struct i2c_client *client)
> +{
> +	struct v4l2_subdev *sd = i2c_get_clientdata(client);
> +	struct dw9768 *dw9768 = sd_to_dw9768(sd);
> +
> +	pm_runtime_disable(&client->dev);
> +	v4l2_async_unregister_subdev(&dw9768->sd);
> +	v4l2_ctrl_handler_free(&dw9768->ctrls);
> +	media_entity_cleanup(&dw9768->sd.entity);
> +	if (!pm_runtime_status_suspended(&client->dev))
> +		dw9768_runtime_suspend(&client->dev);
> +	pm_runtime_set_suspended(&client->dev);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id dw9768_of_table[] = {
> +	{ .compatible = "dongwoon,dw9768" },
> +	{}
> +};
> +MODULE_DEVICE_TABLE(of, dw9768_of_table);
> +
> +static const struct dev_pm_ops dw9768_pm_ops = {
> +	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
> +				pm_runtime_force_resume)
> +	SET_RUNTIME_PM_OPS(dw9768_runtime_suspend, dw9768_runtime_resume, NULL)
> +};
> +
> +static struct i2c_driver dw9768_i2c_driver = {
> +	.driver = {
> +		.name = DW9768_NAME,
> +		.pm = IS_ENABLED(CONFIG_PM) ? &dw9768_pm_ops : NULL,

You can drop the condition as the driver depends on CONFIG_PM.

> +		.of_match_table = dw9768_of_table,
> +	},
> +	.probe_new  = dw9768_probe,
> +	.remove = dw9768_remove,
> +};
> +
> +module_i2c_driver(dw9768_i2c_driver);
> +
> +MODULE_AUTHOR("Dongchun Zhu <dongchun.zhu@mediatek.com>");
> +MODULE_DESCRIPTION("DW9768 VCM driver");
> +MODULE_LICENSE("GPL v2");
Dongchun Zhu April 30, 2020, 8:47 a.m. UTC | #5 
Hello Andy,

Thanks for the review.

On Tue, 2020-03-31 at 13:14 +0300, Andy Shevchenko wrote:
> On Tue, Mar 31, 2020 at 10:16:20AM +0800, Dongchun Zhu wrote:
> > On Mon, 2020-03-30 at 16:57 +0300, Andy Shevchenko wrote:
> > > On Mon, Mar 30, 2020 at 08:36:34PM +0800, Dongchun Zhu wrote:
> > > > This patch adds a V4L2 sub-device driver for DW9768 voice coil moter,
> > > > providing control to set the desired focus via I2C serial interface.
> > > 
> > > ...
> > > 
> > > > +static const struct dev_pm_ops dw9768_pm_ops = {
> > > > +	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
> > > > +				pm_runtime_force_resume)
> > > > +	SET_RUNTIME_PM_OPS(dw9768_runtime_suspend, dw9768_runtime_resume, NULL)
> > > > +};
> > > > +
> > > > +static struct i2c_driver dw9768_i2c_driver = {
> > > > +	.driver = {
> > > > +		.name = DW9768_NAME,
> > > 
> > > > +		.pm = IS_ENABLED(CONFIG_PM) ? &dw9768_pm_ops : NULL,
> > > 
> > > What is this conditional for?
> > > 
> > 
> > For the dw9768_pm_ops, here my idea is to use an IS_ENABLED() check to
> > avoid defining the structure when CONFIG_PM is not set.
> 
> Have you looked at the implementation of SET_SYSTEM_SLEEP_OPS() and another one?
> 
> Have you tried to actually compile with !CONFIG_PM? In your case the warning
> should be issued.
> 

Understood.
Follow Sakari's advice, the condition would be dropped in next release.
Dongchun Zhu April 30, 2020, 10:15 a.m. UTC | #6 
Hi Sakari,

Thanks for the review.

On Thu, 2020-04-02 at 15:32 +0300, Sakari Ailus wrote:
> Hi Dongchun,
> 
> On Mon, Mar 30, 2020 at 08:36:34PM +0800, Dongchun Zhu wrote:
> > This patch adds a V4L2 sub-device driver for DW9768 voice coil moter,
> > providing control to set the desired focus via I2C serial interface.
> > 
> > Signed-off-by: Dongchun Zhu <dongchun.zhu@mediatek.com>
> > ---
> >  MAINTAINERS                |   1 +
> >  drivers/media/i2c/Kconfig  |  11 ++
> >  drivers/media/i2c/Makefile |   1 +
> >  drivers/media/i2c/dw9768.c | 432 +++++++++++++++++++++++++++++++++++++++++++++
> >  4 files changed, 445 insertions(+)
> >  create mode 100644 drivers/media/i2c/dw9768.c
> > 
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index 5e124d2..e007a1b 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -5140,6 +5140,7 @@ L:	linux-media@vger.kernel.org
> >  S:	Maintained
> >  T:	git git://linuxtv.org/media_tree.git
> >  F:	Documentation/devicetree/bindings/media/i2c/dongwoon,dw9768.yaml
> > +F:	drivers/media/i2c/dw9768.c
> >  
> >  DONGWOON DW9807 LENS VOICE COIL DRIVER
> >  M:	Sakari Ailus <sakari.ailus@linux.intel.com>
> > diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
> > index c68e002..b759d3d 100644
> > --- a/drivers/media/i2c/Kconfig
> > +++ b/drivers/media/i2c/Kconfig
> > @@ -1024,6 +1024,17 @@ config VIDEO_DW9714
> >  	  capability. This is designed for linear control of
> >  	  voice coil motors, controlled via I2C serial interface.
> >  
> > +config VIDEO_DW9768
> > +	tristate "DW9768 lens voice coil support"
> > +	depends on I2C && VIDEO_V4L2 && MEDIA_CONTROLLER
> > +	depends on VIDEO_V4L2_SUBDEV_API
> > +	depends on PM
> > +	help
> > +	  This is a driver for the DW9768 camera lens voice coil.
> > +	  DW9768 is a 10 bit DAC with 100mA output current sink
> > +	  capability. This is designed for linear control of
> > +	  voice coil motors, controlled via I2C serial interface.
> > +
> >  config VIDEO_DW9807_VCM
> >  	tristate "DW9807 lens voice coil support"
> >  	depends on I2C && VIDEO_V4L2 && MEDIA_CONTROLLER
> > diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
> > index c147bb9..ec94434 100644
> > --- a/drivers/media/i2c/Makefile
> > +++ b/drivers/media/i2c/Makefile
> > @@ -24,6 +24,7 @@ obj-$(CONFIG_VIDEO_SAA6752HS) += saa6752hs.o
> >  obj-$(CONFIG_VIDEO_AD5820)  += ad5820.o
> >  obj-$(CONFIG_VIDEO_AK7375)  += ak7375.o
> >  obj-$(CONFIG_VIDEO_DW9714)  += dw9714.o
> > +obj-$(CONFIG_VIDEO_DW9768)  += dw9768.o
> >  obj-$(CONFIG_VIDEO_DW9807_VCM)  += dw9807-vcm.o
> >  obj-$(CONFIG_VIDEO_ADV7170) += adv7170.o
> >  obj-$(CONFIG_VIDEO_ADV7175) += adv7175.o
> > diff --git a/drivers/media/i2c/dw9768.c b/drivers/media/i2c/dw9768.c
> > new file mode 100644
> > index 0000000..f63afa1
> > --- /dev/null
> > +++ b/drivers/media/i2c/dw9768.c
> > @@ -0,0 +1,432 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +// Copyright (c) 2020 MediaTek Inc.
> > +
> > +#include <linux/delay.h>
> > +#include <linux/i2c.h>
> > +#include <linux/module.h>
> > +#include <linux/pm_runtime.h>
> > +#include <linux/regulator/consumer.h>
> > +#include <media/v4l2-async.h>
> > +#include <media/v4l2-ctrls.h>
> > +#include <media/v4l2-device.h>
> > +#include <media/v4l2-subdev.h>
> > +
> > +#define DW9768_NAME				"dw9768"
> > +#define DW9768_MAX_FOCUS_POS			(1024 - 1)
> > +/*
> > + * This sets the minimum granularity for the focus positions.
> > + * A value of 1 gives maximum accuracy for a desired focus position
> > + */
> > +#define DW9768_FOCUS_STEPS			1
> > +
> > +/*
> > + * Ring control and Power control register
> > + * Bit[1] RING_EN
> > + * 0: Direct mode
> > + * 1: AAC mode (ringing control mode)
> > + * Bit[0] PD
> > + * 0: Normal operation mode
> > + * 1: Power down mode
> > + * DW9768 requires waiting time of Topr after PD reset takes place.
> > + */
> > +#define DW9768_RING_PD_CONTROL_REG		0x02
> > +#define DW9768_PD_MODE_OFF			0x00
> > +#define DW9768_PD_MODE_EN			BIT(0)
> > +#define DW9768_AAC_MODE_EN			BIT(1)
> > +
> > +/*
> > + * DW9768 separates two registers to control the VCM position.
> > + * One for MSB value, another is LSB value.
> > + * DAC_MSB: D[9:8] (ADD: 0x03)
> > + * DAC_LSB: D[7:0] (ADD: 0x04)
> > + * D[9:0] DAC data input: positive output current = D[9:0] / 1023 * 100[mA]
> > + */
> > +#define DW9768_MSB_ADDR				0x03
> > +#define DW9768_LSB_ADDR				0x04
> > +#define DW9768_STATUS_ADDR			0x05
> > +
> > +/*
> > + * AAC mode control & prescale register
> > + * Bit[7:5] Namely AC[2:0], decide the VCM mode and operation time.
> > + * 000 Direct(default)
> > + * 001 AAC2 0.48xTvib
> > + * 010 AAC3 0.70xTvib
> > + * 011 AAC4 0.75xTvib
> > + * 100 Reserved
> > + * 101 AAC8 1.13xTvib
> > + * 110 Reserved
> > + * 111 Reserved
> > + * Bit[2:0] Namely PRESC[2:0], set the internal clock dividing rate as follow.
> > + * 000 2
> > + * 001 1(default)
> > + * 010 1/2
> > + * 011 1/4
> > + * 100 8
> > + * 101 4
> > + * 110 Reserved
> > + * 111 Reserved
> > + */
> > +#define DW9768_AAC_PRESC_REG			0x06
> > +#define DW9768_AAC3_SELECT_DIVIDING_RATE_1	0x41
> > +
> > +/*
> > + * VCM period of vibration register
> > + * Bit[5:0] Defined as VCM rising periodic time (Tvib) together with PRESC[2:0]
> > + * Tvib = (6.3ms + AACT[5:0] * 0.1ms) * Dividing Rate
> > + * Dividing Rate is the internal clock dividing rate that is defined at
> > + * PRESCALE register (ADD: 0x06)
> > + */
> > +#define DW9768_AAC_TIME_REG			0x07
> > +#define DW9768_AACT_CNT				0x39
> > +
> > +/*
> > + * DW9768 requires waiting time (delay time) of t_OPR after power-up,
> > + * or in the case of PD reset taking place.
> > + */
> > +#define DW9768_T_OPR_US				1000
> > +
> > +/*
> > + * This acts as the minimum granularity of lens movement.
> > + * Keep this value power of 2, so the control steps can be
> > + * uniformly adjusted for gradual lens movement, with desired
> > + * number of control steps.
> > + */
> > +#define DW9768_MOVE_STEPS			16
> > +
> > +/*
> > + * DW9768_AAC_PRESC_REG & DW9768_AAC_TIME_REG determine VCM operation time.
> > + * If DW9768_AAC_PRESC_REG is 0x41, and DW9768_AAC_TIME_REG is 0x39, VCM mode
> > + * would be AAC3, Operation Time would be 0.70xTvib, that is 8.40ms.
> > + */
> > +#define DW9768_MOVE_DELAY_US			8400
> > +#define DW9768_STABLE_TIME_US			20000
> > +
> > +static const char * const dw9768_supply_names[] = {
> > +	"vin",	/* I2C I/O interface power */
> > +	"vdd",	/* VCM power */
> > +};
> > +
> > +/* dw9768 device structure */
> > +struct dw9768 {
> > +	struct regulator_bulk_data supplies[ARRAY_SIZE(dw9768_supply_names)];
> > +	struct v4l2_ctrl_handler ctrls;
> > +	struct v4l2_ctrl *focus;
> > +	struct v4l2_subdev sd;
> > +};
> > +
> > +static inline struct dw9768 *to_dw9768(struct v4l2_ctrl *ctrl)
> > +{
> > +	return container_of(ctrl->handler, struct dw9768, ctrls);
> > +}
> > +
> > +static inline struct dw9768 *sd_to_dw9768(struct v4l2_subdev *subdev)
> > +{
> > +	return container_of(subdev, struct dw9768, sd);
> > +}
> > +
> > +struct regval_list {
> > +	u8 reg_num;
> > +	u8 value;
> > +};
> > +
> > +static const struct regval_list dw9768_init_regs[] = {
> > +	{DW9768_RING_PD_CONTROL_REG, DW9768_AAC_MODE_EN},
> > +	{DW9768_AAC_PRESC_REG, DW9768_AAC3_SELECT_DIVIDING_RATE_1},
> > +	{DW9768_AAC_TIME_REG, DW9768_AACT_CNT},
> 
> Apologies for missing to follow the earlier discussion related to this.
> 
> I wonder if these values are specific to a given lens or a module.
> Presumably so, as they're changed from the defaults.
> 
> In that case I'd put them to DT.
> 

The earlier discussion related to this could be found here:
https://lore.kernel.org/linux-media/1584526824.5781.56.camel@mhfsdcap03/

For one specific driver, the register settings are supposed to be
adjusted according to hardware specification or vendor's suggestion.

Like OV8856, we also need to set series of registers by changing the
default values.

Personally DT properties may need to be created once a new board
requires different values.

What do you think?

> > +};
> > +
> > +static int dw9768_write_array(struct dw9768 *dw9768,
> > +			      const struct regval_list *vals, size_t len)
> > +{
> > +	struct i2c_client *client = v4l2_get_subdevdata(&dw9768->sd);
> > +	unsigned int i;
> > +	int ret;
> > +
> > +	for (i = 0; i < len; i++) {
> > +		ret = i2c_smbus_write_byte_data(client, vals[i].reg_num,
> > +						vals[i].value);
> > +		if (ret < 0)
> > +			return ret;
> > +	}
> > +	return 0;
> > +}
> > +
> > +static int dw9768_set_dac(struct dw9768 *dw9768, u16 val)
> > +{
> > +	struct i2c_client *client = v4l2_get_subdevdata(&dw9768->sd);
> > +
> > +	/* Write VCM position to registers */
> > +	return i2c_smbus_write_word_swapped(client, DW9768_MSB_ADDR, val);
> > +}
> > +
> > +static int dw9768_init(struct dw9768 *dw9768)
> > +{
> > +	struct i2c_client *client = v4l2_get_subdevdata(&dw9768->sd);
> > +	int ret, val;
> > +
> > +	/* Reset DW9768_RING_PD_CONTROL_REG to default status 0x00 */
> > +	ret = i2c_smbus_write_byte_data(client, DW9768_RING_PD_CONTROL_REG,
> > +					DW9768_PD_MODE_OFF);
> > +	if (ret < 0)
> > +		return ret;
> > +
> > +	/*
> > +	 * DW9769 requires waiting delay time of t_OPR
> > +	 * after PD reset takes place.
> > +	 */
> > +	usleep_range(DW9768_T_OPR_US, DW9768_T_OPR_US + 100);
> > +
> > +	ret = dw9768_write_array(dw9768, dw9768_init_regs,
> > +				 ARRAY_SIZE(dw9768_init_regs));
> > +	if (ret)
> > +		return ret;
> > +
> > +	for (val = dw9768->focus->val % DW9768_MOVE_STEPS;
> > +	     val <= dw9768->focus->val;
> > +	     val += DW9768_MOVE_STEPS) {
> > +		ret = dw9768_set_dac(dw9768, val);
> > +		if (ret) {
> > +			dev_err(&client->dev, "I2C write fail: %d", ret);
> > +			return ret;
> > +		}
> > +		usleep_range(DW9768_MOVE_DELAY_US, DW9768_MOVE_DELAY_US + 1000);
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static int dw9768_release(struct dw9768 *dw9768)
> > +{
> > +	struct i2c_client *client = v4l2_get_subdevdata(&dw9768->sd);
> > +	int ret, val;
> > +
> > +	val = round_down(dw9768->focus->val, DW9768_MOVE_STEPS);
> > +	for ( ; val >= 0; val -= DW9768_MOVE_STEPS) {
> > +		ret = dw9768_set_dac(dw9768, val);
> > +		if (ret) {
> > +			dev_err(&client->dev, "I2C write fail: %d", ret);
> > +			return ret;
> > +		}
> > +		usleep_range(DW9768_MOVE_DELAY_US, DW9768_MOVE_DELAY_US + 1000);
> > +	}
> > +
> > +	/*
> > +	 * Wait for the motor to stabilize after the last movement
> > +	 * to prevent the motor from shaking.
> > +	 */
> > +	usleep_range(DW9768_STABLE_TIME_US - DW9768_MOVE_DELAY_US,
> > +		     DW9768_STABLE_TIME_US - DW9768_MOVE_DELAY_US + 1000);
> > +
> > +	ret = i2c_smbus_write_byte_data(client, DW9768_RING_PD_CONTROL_REG,
> > +					DW9768_PD_MODE_EN);
> > +	if (ret < 0)
> > +		return ret;
> > +
> > +	/*
> > +	 * DW9769 requires waiting delay time of t_OPR
> > +	 * after PD reset takes place.
> > +	 */
> > +	usleep_range(DW9768_T_OPR_US, DW9768_T_OPR_US + 100);
> > +
> > +	return 0;
> > +}
> > +
> > +static int __maybe_unused dw9768_runtime_suspend(struct device *dev)
> > +{
> > +	struct i2c_client *client = to_i2c_client(dev);
> > +	struct v4l2_subdev *sd = i2c_get_clientdata(client);
> > +	struct dw9768 *dw9768 = sd_to_dw9768(sd);
> > +
> > +	dw9768_release(dw9768);
> > +	regulator_bulk_disable(ARRAY_SIZE(dw9768_supply_names),
> > +			       dw9768->supplies);
> > +
> > +	return 0;
> > +}
> > +
> > +static int __maybe_unused dw9768_runtime_resume(struct device *dev)
> > +{
> > +	struct i2c_client *client = to_i2c_client(dev);
> > +	struct v4l2_subdev *sd = i2c_get_clientdata(client);
> > +	struct dw9768 *dw9768 = sd_to_dw9768(sd);
> > +	int ret;
> > +
> > +	ret = regulator_bulk_enable(ARRAY_SIZE(dw9768_supply_names),
> > +				    dw9768->supplies);
> > +	if (ret < 0) {
> > +		dev_err(dev, "failed to enable regulators\n");
> > +		return ret;
> > +	}
> > +
> > +	/*
> > +	 * The datasheet refers to t_OPR that needs to be waited before sending
> > +	 * I2C commands after power-up.
> > +	 */
> > +	usleep_range(DW9768_T_OPR_US, DW9768_T_OPR_US + 100);
> > +
> > +	ret = dw9768_init(dw9768);
> > +	if (ret < 0)
> > +		goto disable_regulator;
> > +
> > +	return 0;
> > +
> > +disable_regulator:
> > +	regulator_bulk_disable(ARRAY_SIZE(dw9768_supply_names),
> > +			       dw9768->supplies);
> > +
> > +	return ret;
> > +}
> > +
> > +static int dw9768_set_ctrl(struct v4l2_ctrl *ctrl)
> > +{
> > +	struct dw9768 *dw9768 = to_dw9768(ctrl);
> > +
> > +	if (ctrl->id == V4L2_CID_FOCUS_ABSOLUTE)
> > +		return dw9768_set_dac(dw9768, ctrl->val);
> > +
> > +	return 0;
> > +}
> > +
> > +static const struct v4l2_ctrl_ops dw9768_ctrl_ops = {
> > +	.s_ctrl = dw9768_set_ctrl,
> > +};
> > +
> > +static int dw9768_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
> > +{
> > +	int ret;
> > +
> > +	ret = pm_runtime_get_sync(sd->dev);
> > +	if (ret < 0) {
> > +		pm_runtime_put_noidle(sd->dev);
> > +		return ret;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static int dw9768_close(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
> > +{
> > +	pm_runtime_put(sd->dev);
> > +
> > +	return 0;
> > +}
> > +
> > +static const struct v4l2_subdev_internal_ops dw9768_int_ops = {
> > +	.open = dw9768_open,
> > +	.close = dw9768_close,
> > +};
> > +
> > +static const struct v4l2_subdev_ops dw9768_ops = { };
> > +
> > +static int dw9768_init_controls(struct dw9768 *dw9768)
> > +{
> > +	struct v4l2_ctrl_handler *hdl = &dw9768->ctrls;
> > +	const struct v4l2_ctrl_ops *ops = &dw9768_ctrl_ops;
> > +
> > +	v4l2_ctrl_handler_init(hdl, 1);
> > +
> > +	dw9768->focus = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FOCUS_ABSOLUTE, 0,
> > +					  DW9768_MAX_FOCUS_POS,
> > +					  DW9768_FOCUS_STEPS, 0);
> > +
> > +	if (hdl->error)
> > +		return hdl->error;
> > +
> > +	dw9768->sd.ctrl_handler = hdl;
> > +
> > +	return 0;
> > +}
> > +
> > +static int dw9768_probe(struct i2c_client *client)
> > +{
> > +	struct device *dev = &client->dev;
> > +	struct dw9768 *dw9768;
> > +	unsigned int i;
> > +	int ret;
> > +
> > +	dw9768 = devm_kzalloc(dev, sizeof(*dw9768), GFP_KERNEL);
> > +	if (!dw9768)
> > +		return -ENOMEM;
> > +
> > +	v4l2_i2c_subdev_init(&dw9768->sd, client, &dw9768_ops);
> > +
> > +	for (i = 0; i < ARRAY_SIZE(dw9768_supply_names); i++)
> > +		dw9768->supplies[i].supply = dw9768_supply_names[i];
> > +
> > +	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(dw9768_supply_names),
> > +				      dw9768->supplies);
> > +	if (ret) {
> > +		dev_err(dev, "failed to get regulators\n");
> > +		return ret;
> > +	}
> > +
> > +	ret = dw9768_init_controls(dw9768);
> > +	if (ret)
> > +		goto entity_cleanup;
> > +
> > +	dw9768->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> > +	dw9768->sd.internal_ops = &dw9768_int_ops;
> > +
> > +	ret = media_entity_pads_init(&dw9768->sd.entity, 0, NULL);
> > +	if (ret < 0)
> > +		goto entity_cleanup;
> > +
> > +	dw9768->sd.entity.function = MEDIA_ENT_F_LENS;
> > +
> > +	ret = v4l2_async_register_subdev(&dw9768->sd);
> > +	if (ret < 0)
> > +		goto entity_cleanup;
> > +
> > +	pm_runtime_enable(dev);
> 
> Note that here, the device node may be already created before runtime PM is
> enabled.
> 
> Could you reverse order of enabling runtime PM and registering the async
> subdev to fix that?
> 

Got it.
We would also add PM enabled status check by using
pm_runtime_enabled(dev) in next release.
Such as:
pm_runtime_enable(dev);
if (!pm_runtime_enabled(dev)) {
	ret = dw9768_runtime_resume(dev);
	if (ret < 0 ) {
		dev_err(dev, "failed to power on: %d\n", ret);
		goto entity_cleanup;
	}
}

ret = v4l2_async_register_subdev(&dw9768->sd);
if (ret < 0)
	goto entity_cleanup;

> > +
> > +	return 0;
> > +
> > +entity_cleanup:
> > +	v4l2_ctrl_handler_free(&dw9768->ctrls);
> > +	media_entity_cleanup(&dw9768->sd.entity);
> > +	return ret;
> > +}
> > +
> > +static int dw9768_remove(struct i2c_client *client)
> > +{
> > +	struct v4l2_subdev *sd = i2c_get_clientdata(client);
> > +	struct dw9768 *dw9768 = sd_to_dw9768(sd);
> > +
> > +	pm_runtime_disable(&client->dev);
> > +	v4l2_async_unregister_subdev(&dw9768->sd);
> > +	v4l2_ctrl_handler_free(&dw9768->ctrls);
> > +	media_entity_cleanup(&dw9768->sd.entity);
> > +	if (!pm_runtime_status_suspended(&client->dev))
> > +		dw9768_runtime_suspend(&client->dev);
> > +	pm_runtime_set_suspended(&client->dev);
> > +
> > +	return 0;
> > +}
> > +
> > +static const struct of_device_id dw9768_of_table[] = {
> > +	{ .compatible = "dongwoon,dw9768" },
> > +	{}
> > +};
> > +MODULE_DEVICE_TABLE(of, dw9768_of_table);
> > +
> > +static const struct dev_pm_ops dw9768_pm_ops = {
> > +	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
> > +				pm_runtime_force_resume)
> > +	SET_RUNTIME_PM_OPS(dw9768_runtime_suspend, dw9768_runtime_resume, NULL)
> > +};
> > +
> > +static struct i2c_driver dw9768_i2c_driver = {
> > +	.driver = {
> > +		.name = DW9768_NAME,
> > +		.pm = IS_ENABLED(CONFIG_PM) ? &dw9768_pm_ops : NULL,
> 
> You can drop the condition as the driver depends on CONFIG_PM.
> 

Thanks for the reminder.
We'd remove that in next release.

> > +		.of_match_table = dw9768_of_table,
> > +	},
> > +	.probe_new  = dw9768_probe,
> > +	.remove = dw9768_remove,
> > +};
> > +
> > +module_i2c_driver(dw9768_i2c_driver);
> > +
> > +MODULE_AUTHOR("Dongchun Zhu <dongchun.zhu@mediatek.com>");
> > +MODULE_DESCRIPTION("DW9768 VCM driver");
> > +MODULE_LICENSE("GPL v2");
>
diff mbox series

Patch

diff --git a/MAINTAINERS b/MAINTAINERS
index 5e124d2..e007a1b 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5140,6 +5140,7 @@  L:	linux-media@vger.kernel.org
 S:	Maintained
 T:	git git://linuxtv.org/media_tree.git
 F:	Documentation/devicetree/bindings/media/i2c/dongwoon,dw9768.yaml
+F:	drivers/media/i2c/dw9768.c
 
 DONGWOON DW9807 LENS VOICE COIL DRIVER
 M:	Sakari Ailus <sakari.ailus@linux.intel.com>
diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
index c68e002..b759d3d 100644
--- a/drivers/media/i2c/Kconfig
+++ b/drivers/media/i2c/Kconfig
@@ -1024,6 +1024,17 @@  config VIDEO_DW9714
 	  capability. This is designed for linear control of
 	  voice coil motors, controlled via I2C serial interface.
 
+config VIDEO_DW9768
+	tristate "DW9768 lens voice coil support"
+	depends on I2C && VIDEO_V4L2 && MEDIA_CONTROLLER
+	depends on VIDEO_V4L2_SUBDEV_API
+	depends on PM
+	help
+	  This is a driver for the DW9768 camera lens voice coil.
+	  DW9768 is a 10 bit DAC with 100mA output current sink
+	  capability. This is designed for linear control of
+	  voice coil motors, controlled via I2C serial interface.
+
 config VIDEO_DW9807_VCM
 	tristate "DW9807 lens voice coil support"
 	depends on I2C && VIDEO_V4L2 && MEDIA_CONTROLLER
diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
index c147bb9..ec94434 100644
--- a/drivers/media/i2c/Makefile
+++ b/drivers/media/i2c/Makefile
@@ -24,6 +24,7 @@  obj-$(CONFIG_VIDEO_SAA6752HS) += saa6752hs.o
 obj-$(CONFIG_VIDEO_AD5820)  += ad5820.o
 obj-$(CONFIG_VIDEO_AK7375)  += ak7375.o
 obj-$(CONFIG_VIDEO_DW9714)  += dw9714.o
+obj-$(CONFIG_VIDEO_DW9768)  += dw9768.o
 obj-$(CONFIG_VIDEO_DW9807_VCM)  += dw9807-vcm.o
 obj-$(CONFIG_VIDEO_ADV7170) += adv7170.o
 obj-$(CONFIG_VIDEO_ADV7175) += adv7175.o
diff --git a/drivers/media/i2c/dw9768.c b/drivers/media/i2c/dw9768.c
new file mode 100644
index 0000000..f63afa1
--- /dev/null
+++ b/drivers/media/i2c/dw9768.c
@@ -0,0 +1,432 @@ 
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2020 MediaTek Inc.
+
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/pm_runtime.h>
+#include <linux/regulator/consumer.h>
+#include <media/v4l2-async.h>
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-subdev.h>
+
+#define DW9768_NAME				"dw9768"
+#define DW9768_MAX_FOCUS_POS			(1024 - 1)
+/*
+ * This sets the minimum granularity for the focus positions.
+ * A value of 1 gives maximum accuracy for a desired focus position
+ */
+#define DW9768_FOCUS_STEPS			1
+
+/*
+ * Ring control and Power control register
+ * Bit[1] RING_EN
+ * 0: Direct mode
+ * 1: AAC mode (ringing control mode)
+ * Bit[0] PD
+ * 0: Normal operation mode
+ * 1: Power down mode
+ * DW9768 requires waiting time of Topr after PD reset takes place.
+ */
+#define DW9768_RING_PD_CONTROL_REG		0x02
+#define DW9768_PD_MODE_OFF			0x00
+#define DW9768_PD_MODE_EN			BIT(0)
+#define DW9768_AAC_MODE_EN			BIT(1)
+
+/*
+ * DW9768 separates two registers to control the VCM position.
+ * One for MSB value, another is LSB value.
+ * DAC_MSB: D[9:8] (ADD: 0x03)
+ * DAC_LSB: D[7:0] (ADD: 0x04)
+ * D[9:0] DAC data input: positive output current = D[9:0] / 1023 * 100[mA]
+ */
+#define DW9768_MSB_ADDR				0x03
+#define DW9768_LSB_ADDR				0x04
+#define DW9768_STATUS_ADDR			0x05
+
+/*
+ * AAC mode control & prescale register
+ * Bit[7:5] Namely AC[2:0], decide the VCM mode and operation time.
+ * 000 Direct(default)
+ * 001 AAC2 0.48xTvib
+ * 010 AAC3 0.70xTvib
+ * 011 AAC4 0.75xTvib
+ * 100 Reserved
+ * 101 AAC8 1.13xTvib
+ * 110 Reserved
+ * 111 Reserved
+ * Bit[2:0] Namely PRESC[2:0], set the internal clock dividing rate as follow.
+ * 000 2
+ * 001 1(default)
+ * 010 1/2
+ * 011 1/4
+ * 100 8
+ * 101 4
+ * 110 Reserved
+ * 111 Reserved
+ */
+#define DW9768_AAC_PRESC_REG			0x06
+#define DW9768_AAC3_SELECT_DIVIDING_RATE_1	0x41
+
+/*
+ * VCM period of vibration register
+ * Bit[5:0] Defined as VCM rising periodic time (Tvib) together with PRESC[2:0]
+ * Tvib = (6.3ms + AACT[5:0] * 0.1ms) * Dividing Rate
+ * Dividing Rate is the internal clock dividing rate that is defined at
+ * PRESCALE register (ADD: 0x06)
+ */
+#define DW9768_AAC_TIME_REG			0x07
+#define DW9768_AACT_CNT				0x39
+
+/*
+ * DW9768 requires waiting time (delay time) of t_OPR after power-up,
+ * or in the case of PD reset taking place.
+ */
+#define DW9768_T_OPR_US				1000
+
+/*
+ * This acts as the minimum granularity of lens movement.
+ * Keep this value power of 2, so the control steps can be
+ * uniformly adjusted for gradual lens movement, with desired
+ * number of control steps.
+ */
+#define DW9768_MOVE_STEPS			16
+
+/*
+ * DW9768_AAC_PRESC_REG & DW9768_AAC_TIME_REG determine VCM operation time.
+ * If DW9768_AAC_PRESC_REG is 0x41, and DW9768_AAC_TIME_REG is 0x39, VCM mode
+ * would be AAC3, Operation Time would be 0.70xTvib, that is 8.40ms.
+ */
+#define DW9768_MOVE_DELAY_US			8400
+#define DW9768_STABLE_TIME_US			20000
+
+static const char * const dw9768_supply_names[] = {
+	"vin",	/* I2C I/O interface power */
+	"vdd",	/* VCM power */
+};
+
+/* dw9768 device structure */
+struct dw9768 {
+	struct regulator_bulk_data supplies[ARRAY_SIZE(dw9768_supply_names)];
+	struct v4l2_ctrl_handler ctrls;
+	struct v4l2_ctrl *focus;
+	struct v4l2_subdev sd;
+};
+
+static inline struct dw9768 *to_dw9768(struct v4l2_ctrl *ctrl)
+{
+	return container_of(ctrl->handler, struct dw9768, ctrls);
+}
+
+static inline struct dw9768 *sd_to_dw9768(struct v4l2_subdev *subdev)
+{
+	return container_of(subdev, struct dw9768, sd);
+}
+
+struct regval_list {
+	u8 reg_num;
+	u8 value;
+};
+
+static const struct regval_list dw9768_init_regs[] = {
+	{DW9768_RING_PD_CONTROL_REG, DW9768_AAC_MODE_EN},
+	{DW9768_AAC_PRESC_REG, DW9768_AAC3_SELECT_DIVIDING_RATE_1},
+	{DW9768_AAC_TIME_REG, DW9768_AACT_CNT},
+};
+
+static int dw9768_write_array(struct dw9768 *dw9768,
+			      const struct regval_list *vals, size_t len)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(&dw9768->sd);
+	unsigned int i;
+	int ret;
+
+	for (i = 0; i < len; i++) {
+		ret = i2c_smbus_write_byte_data(client, vals[i].reg_num,
+						vals[i].value);
+		if (ret < 0)
+			return ret;
+	}
+	return 0;
+}
+
+static int dw9768_set_dac(struct dw9768 *dw9768, u16 val)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(&dw9768->sd);
+
+	/* Write VCM position to registers */
+	return i2c_smbus_write_word_swapped(client, DW9768_MSB_ADDR, val);
+}
+
+static int dw9768_init(struct dw9768 *dw9768)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(&dw9768->sd);
+	int ret, val;
+
+	/* Reset DW9768_RING_PD_CONTROL_REG to default status 0x00 */
+	ret = i2c_smbus_write_byte_data(client, DW9768_RING_PD_CONTROL_REG,
+					DW9768_PD_MODE_OFF);
+	if (ret < 0)
+		return ret;
+
+	/*
+	 * DW9769 requires waiting delay time of t_OPR
+	 * after PD reset takes place.
+	 */
+	usleep_range(DW9768_T_OPR_US, DW9768_T_OPR_US + 100);
+
+	ret = dw9768_write_array(dw9768, dw9768_init_regs,
+				 ARRAY_SIZE(dw9768_init_regs));
+	if (ret)
+		return ret;
+
+	for (val = dw9768->focus->val % DW9768_MOVE_STEPS;
+	     val <= dw9768->focus->val;
+	     val += DW9768_MOVE_STEPS) {
+		ret = dw9768_set_dac(dw9768, val);
+		if (ret) {
+			dev_err(&client->dev, "I2C write fail: %d", ret);
+			return ret;
+		}
+		usleep_range(DW9768_MOVE_DELAY_US, DW9768_MOVE_DELAY_US + 1000);
+	}
+
+	return 0;
+}
+
+static int dw9768_release(struct dw9768 *dw9768)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(&dw9768->sd);
+	int ret, val;
+
+	val = round_down(dw9768->focus->val, DW9768_MOVE_STEPS);
+	for ( ; val >= 0; val -= DW9768_MOVE_STEPS) {
+		ret = dw9768_set_dac(dw9768, val);
+		if (ret) {
+			dev_err(&client->dev, "I2C write fail: %d", ret);
+			return ret;
+		}
+		usleep_range(DW9768_MOVE_DELAY_US, DW9768_MOVE_DELAY_US + 1000);
+	}
+
+	/*
+	 * Wait for the motor to stabilize after the last movement
+	 * to prevent the motor from shaking.
+	 */
+	usleep_range(DW9768_STABLE_TIME_US - DW9768_MOVE_DELAY_US,
+		     DW9768_STABLE_TIME_US - DW9768_MOVE_DELAY_US + 1000);
+
+	ret = i2c_smbus_write_byte_data(client, DW9768_RING_PD_CONTROL_REG,
+					DW9768_PD_MODE_EN);
+	if (ret < 0)
+		return ret;
+
+	/*
+	 * DW9769 requires waiting delay time of t_OPR
+	 * after PD reset takes place.
+	 */
+	usleep_range(DW9768_T_OPR_US, DW9768_T_OPR_US + 100);
+
+	return 0;
+}
+
+static int __maybe_unused dw9768_runtime_suspend(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct v4l2_subdev *sd = i2c_get_clientdata(client);
+	struct dw9768 *dw9768 = sd_to_dw9768(sd);
+
+	dw9768_release(dw9768);
+	regulator_bulk_disable(ARRAY_SIZE(dw9768_supply_names),
+			       dw9768->supplies);
+
+	return 0;
+}
+
+static int __maybe_unused dw9768_runtime_resume(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct v4l2_subdev *sd = i2c_get_clientdata(client);
+	struct dw9768 *dw9768 = sd_to_dw9768(sd);
+	int ret;
+
+	ret = regulator_bulk_enable(ARRAY_SIZE(dw9768_supply_names),
+				    dw9768->supplies);
+	if (ret < 0) {
+		dev_err(dev, "failed to enable regulators\n");
+		return ret;
+	}
+
+	/*
+	 * The datasheet refers to t_OPR that needs to be waited before sending
+	 * I2C commands after power-up.
+	 */
+	usleep_range(DW9768_T_OPR_US, DW9768_T_OPR_US + 100);
+
+	ret = dw9768_init(dw9768);
+	if (ret < 0)
+		goto disable_regulator;
+
+	return 0;
+
+disable_regulator:
+	regulator_bulk_disable(ARRAY_SIZE(dw9768_supply_names),
+			       dw9768->supplies);
+
+	return ret;
+}
+
+static int dw9768_set_ctrl(struct v4l2_ctrl *ctrl)
+{
+	struct dw9768 *dw9768 = to_dw9768(ctrl);
+
+	if (ctrl->id == V4L2_CID_FOCUS_ABSOLUTE)
+		return dw9768_set_dac(dw9768, ctrl->val);
+
+	return 0;
+}
+
+static const struct v4l2_ctrl_ops dw9768_ctrl_ops = {
+	.s_ctrl = dw9768_set_ctrl,
+};
+
+static int dw9768_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
+{
+	int ret;
+
+	ret = pm_runtime_get_sync(sd->dev);
+	if (ret < 0) {
+		pm_runtime_put_noidle(sd->dev);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int dw9768_close(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
+{
+	pm_runtime_put(sd->dev);
+
+	return 0;
+}
+
+static const struct v4l2_subdev_internal_ops dw9768_int_ops = {
+	.open = dw9768_open,
+	.close = dw9768_close,
+};
+
+static const struct v4l2_subdev_ops dw9768_ops = { };
+
+static int dw9768_init_controls(struct dw9768 *dw9768)
+{
+	struct v4l2_ctrl_handler *hdl = &dw9768->ctrls;
+	const struct v4l2_ctrl_ops *ops = &dw9768_ctrl_ops;
+
+	v4l2_ctrl_handler_init(hdl, 1);
+
+	dw9768->focus = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FOCUS_ABSOLUTE, 0,
+					  DW9768_MAX_FOCUS_POS,
+					  DW9768_FOCUS_STEPS, 0);
+
+	if (hdl->error)
+		return hdl->error;
+
+	dw9768->sd.ctrl_handler = hdl;
+
+	return 0;
+}
+
+static int dw9768_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct dw9768 *dw9768;
+	unsigned int i;
+	int ret;
+
+	dw9768 = devm_kzalloc(dev, sizeof(*dw9768), GFP_KERNEL);
+	if (!dw9768)
+		return -ENOMEM;
+
+	v4l2_i2c_subdev_init(&dw9768->sd, client, &dw9768_ops);
+
+	for (i = 0; i < ARRAY_SIZE(dw9768_supply_names); i++)
+		dw9768->supplies[i].supply = dw9768_supply_names[i];
+
+	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(dw9768_supply_names),
+				      dw9768->supplies);
+	if (ret) {
+		dev_err(dev, "failed to get regulators\n");
+		return ret;
+	}
+
+	ret = dw9768_init_controls(dw9768);
+	if (ret)
+		goto entity_cleanup;
+
+	dw9768->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
+	dw9768->sd.internal_ops = &dw9768_int_ops;
+
+	ret = media_entity_pads_init(&dw9768->sd.entity, 0, NULL);
+	if (ret < 0)
+		goto entity_cleanup;
+
+	dw9768->sd.entity.function = MEDIA_ENT_F_LENS;
+
+	ret = v4l2_async_register_subdev(&dw9768->sd);
+	if (ret < 0)
+		goto entity_cleanup;
+
+	pm_runtime_enable(dev);
+
+	return 0;
+
+entity_cleanup:
+	v4l2_ctrl_handler_free(&dw9768->ctrls);
+	media_entity_cleanup(&dw9768->sd.entity);
+	return ret;
+}
+
+static int dw9768_remove(struct i2c_client *client)
+{
+	struct v4l2_subdev *sd = i2c_get_clientdata(client);
+	struct dw9768 *dw9768 = sd_to_dw9768(sd);
+
+	pm_runtime_disable(&client->dev);
+	v4l2_async_unregister_subdev(&dw9768->sd);
+	v4l2_ctrl_handler_free(&dw9768->ctrls);
+	media_entity_cleanup(&dw9768->sd.entity);
+	if (!pm_runtime_status_suspended(&client->dev))
+		dw9768_runtime_suspend(&client->dev);
+	pm_runtime_set_suspended(&client->dev);
+
+	return 0;
+}
+
+static const struct of_device_id dw9768_of_table[] = {
+	{ .compatible = "dongwoon,dw9768" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, dw9768_of_table);
+
+static const struct dev_pm_ops dw9768_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+				pm_runtime_force_resume)
+	SET_RUNTIME_PM_OPS(dw9768_runtime_suspend, dw9768_runtime_resume, NULL)
+};
+
+static struct i2c_driver dw9768_i2c_driver = {
+	.driver = {
+		.name = DW9768_NAME,
+		.pm = IS_ENABLED(CONFIG_PM) ? &dw9768_pm_ops : NULL,
+		.of_match_table = dw9768_of_table,
+	},
+	.probe_new  = dw9768_probe,
+	.remove = dw9768_remove,
+};
+
+module_i2c_driver(dw9768_i2c_driver);
+
+MODULE_AUTHOR("Dongchun Zhu <dongchun.zhu@mediatek.com>");
+MODULE_DESCRIPTION("DW9768 VCM driver");
+MODULE_LICENSE("GPL v2");