diff mbox series

iio: cros_ec: Add lid angle driver

Message ID 20190228015005.81232-1-gwendal@chromium.org (mailing list archive)
State New, archived
Headers show
Series iio: cros_ec: Add lid angle driver | expand

Commit Message

Gwendal Grignou Feb. 28, 2019, 1:50 a.m. UTC 
Add a IIO driver that reports the angle between the lid and the base for
ChromeOS convertible device.

Tested on eve with ToT EC firmware.
Check driver is loaded and lid angle is correct.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
---
 drivers/iio/common/cros_ec_sensors/Kconfig    |   9 +
 drivers/iio/common/cros_ec_sensors/Makefile   |   1 +
 .../cros_ec_sensors/cros_ec_lid_angle.c       | 164 ++++++++++++++++++
 drivers/mfd/cros_ec_dev.c                     |  15 +-
 4 files changed, 186 insertions(+), 3 deletions(-)
 create mode 100644 drivers/iio/common/cros_ec_sensors/cros_ec_lid_angle.c

Comments

Enric Balletbo i Serra Feb. 28, 2019, 11:18 a.m. UTC | #1 
Hi Gwendal,

Thanks to send this upstream.

On 28/2/19 2:50, Gwendal Grignou wrote:
> Add a IIO driver that reports the angle between the lid and the base for
> ChromeOS convertible device.
> 
> Tested on eve with ToT EC firmware.
> Check driver is loaded and lid angle is correct.
> 
> Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
> ---
>  drivers/iio/common/cros_ec_sensors/Kconfig    |   9 +
>  drivers/iio/common/cros_ec_sensors/Makefile   |   1 +
>  .../cros_ec_sensors/cros_ec_lid_angle.c       | 164 ++++++++++++++++++
>  drivers/mfd/cros_ec_dev.c                     |  15 +-

The mfd/cros_ec_dev.c part looks good to me. I have some few comments in the IIO
part, see below.

>  4 files changed, 186 insertions(+), 3 deletions(-)
>  create mode 100644 drivers/iio/common/cros_ec_sensors/cros_ec_lid_angle.c
> 
> diff --git a/drivers/iio/common/cros_ec_sensors/Kconfig b/drivers/iio/common/cros_ec_sensors/Kconfig
> index 135f6825903f..aacc2ab9c34f 100644
> --- a/drivers/iio/common/cros_ec_sensors/Kconfig
> +++ b/drivers/iio/common/cros_ec_sensors/Kconfig
> @@ -20,3 +20,12 @@ config IIO_CROS_EC_SENSORS
>  	  Accelerometers, Gyroscope and Magnetometer that are
>  	  presented by the ChromeOS EC Sensor hub.
>  	  Creates an IIO device for each functions.
> +
> +config IIO_CROS_EC_SENSORS_LID_ANGLE
> +	tristate "ChromeOS EC Sensor for lid angle"
> +	depends on IIO_CROS_EC_SENSORS_CORE
> +	help
> +	  Module to report the angle between lid and base for some
> +	  convertible devices.
> +	  This module is loaded when the EC can calculate the angle between the base
> +	  and the lid.
> diff --git a/drivers/iio/common/cros_ec_sensors/Makefile b/drivers/iio/common/cros_ec_sensors/Makefile
> index ec716ff2a775..a35ee232ac07 100644
> --- a/drivers/iio/common/cros_ec_sensors/Makefile
> +++ b/drivers/iio/common/cros_ec_sensors/Makefile
> @@ -4,3 +4,4 @@
>  
>  obj-$(CONFIG_IIO_CROS_EC_SENSORS_CORE) += cros_ec_sensors_core.o
>  obj-$(CONFIG_IIO_CROS_EC_SENSORS) += cros_ec_sensors.o
> +obj-$(CONFIG_IIO_CROS_EC_SENSORS_LID_ANGLE) += cros_ec_lid_angle.o
> diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_lid_angle.c b/drivers/iio/common/cros_ec_sensors/cros_ec_lid_angle.c
> new file mode 100644
> index 000000000000..370b3e9a1405
> --- /dev/null
> +++ b/drivers/iio/common/cros_ec_sensors/cros_ec_lid_angle.c
> @@ -0,0 +1,164 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +

There is a license mismatch between the SPDX identifier (GPLv2 or later) and the
MODULE_LICENSE (GPLv2). I think that this should be only GPL-2.0

> +/*
> + * cros_ec_lid_angle - Driver for CrOS EC lid angle sensor.
> + *
> + * Copyright 2018 Google, Inc
> + *
> + * This driver uses the cros-ec interface to communicate with the Chrome OS
> + * EC about counter sensors. Counters are presented through
> + * iio sysfs.
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/device.h>
> +#include <linux/iio/buffer.h>
> +#include <linux/iio/common/cros_ec_sensors_core.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/kfifo_buf.h>
> +#include <linux/iio/trigger.h>
> +#include <linux/iio/triggered_buffer.h>
> +#include <linux/iio/trigger_consumer.h>
> +#include <linux/kernel.h>
> +#include <linux/mfd/cros_ec.h>
> +#include <linux/mfd/cros_ec_commands.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +
> +#define DRV_NAME "cros-ec-lid-angle"
> +
> +/*
> + * One channel for the lid angle, the other for timestamp.
> + */
> +#define MAX_CHANNELS (1 + 1)
> +
> +/* State data for ec_sensors iio driver. */
> +struct cros_ec_lid_angle_state {
> +	/* Shared by all sensors */
> +	struct cros_ec_sensors_core_state core;
> +
> +	struct iio_chan_spec channels[MAX_CHANNELS];
> +};
> +
> +static int cros_ec_sensors_read_lid_angle(struct iio_dev *indio_dev,
> +					  unsigned long scan_mask, s16 *data)
> +{
> +	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
> +	int ret;
> +
> +	st->param.cmd = MOTIONSENSE_CMD_LID_ANGLE;
> +	ret = cros_ec_motion_send_host_cmd(st, sizeof(st->resp->lid_angle));
> +	if (ret) {
> +		dev_warn(&indio_dev->dev, "Unable to read lid angle\n");
> +		return ret;
> +	}
> +
> +	if (scan_mask & 1)
> +		*data = st->resp->lid_angle.value;
> +	return 0;
> +}
> +
> +static int cros_ec_lid_angle_read(struct iio_dev *indio_dev,
> +				    struct iio_chan_spec const *chan,
> +				    int *val, int *val2, long mask)
> +{
> +	struct cros_ec_lid_angle_state *st = iio_priv(indio_dev);
> +	u16 data;
> +	int ret;
> +	int idx = chan->scan_index;
> +
> +	mutex_lock(&st->core.cmd_lock);
> +	switch (mask) {
> +	case IIO_CHAN_INFO_RAW:
> +		ret = cros_ec_sensors_read_lid_angle(
> +				indio_dev, 1 << idx, &data);
> +		if (ret)
> +			break;
> +		ret = IIO_VAL_INT;
> +		*val = data;
> +		break;
> +	default:
> +		ret = -EINVAL;
> +	}
> +	mutex_unlock(&st->core.cmd_lock);
> +	return ret;
> +}
> +
> +static const struct iio_info cros_ec_lid_angle_info = {
> +	.read_raw = &cros_ec_lid_angle_read,
> +	.driver_module = THIS_MODULE,

This is not needed now, you can remove it.

> +};
> +
> +static int cros_ec_lid_angle_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct iio_dev *indio_dev;
> +	struct cros_ec_lid_angle_state *state;
> +	struct iio_chan_spec *channel;
> +	int ret;
> +
> +	indio_dev = devm_iio_device_alloc(dev, sizeof(*state));
> +	if (!indio_dev)
> +		return -ENOMEM;
> +
> +	ret = cros_ec_sensors_core_init(pdev, indio_dev, false);
> +	if (ret)
> +		return ret;
> +
> +	indio_dev->info = &cros_ec_lid_angle_info;
> +	state = iio_priv(indio_dev);
> +	channel = state->channels;
> +
> +	channel->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
> +	channel->scan_type.realbits = CROS_EC_SENSOR_BITS;
> +	channel->scan_type.storagebits = CROS_EC_SENSOR_BITS;
> +	channel->scan_type.shift = 0;
> +	channel->scan_index = 0;
> +	channel->scan_type.sign = 'u';
> +	channel->type = IIO_ANGL;
> +
> +	state->core.calib[0] = 0;
> +
> +	/* Timestamp */
> +	channel++;
> +	channel->type = IIO_TIMESTAMP;
> +	channel->channel = -1;
> +	channel->scan_index = 1;
> +	channel->scan_type.sign = 's';
> +	channel->scan_type.realbits = 64;
> +	channel->scan_type.storagebits = 64;
> +
> +	indio_dev->channels = state->channels;
> +	indio_dev->num_channels = MAX_CHANNELS;
> +
> +	state->core.read_ec_sensors_data = cros_ec_sensors_read_lid_angle;
> +
> +	ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
> +			cros_ec_sensors_capture, NULL);
> +	if (ret)
> +		return ret;
> +
> +	return devm_iio_device_register(dev, indio_dev);
> +}
> +
> +static const struct platform_device_id cros_ec_lid_angle_ids[] = {
> +	{
> +		.name = DRV_NAME,
> +	},
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(platform, cros_ec_lid_angle_ids);
> +
> +static struct platform_driver cros_ec_lid_angle_platform_driver = {
> +	.driver = {
> +		.name	= DRV_NAME,
> +		.pm	= &cros_ec_sensors_pm_ops,
> +	},
> +	.probe		= cros_ec_lid_angle_probe,
> +	.id_table	= cros_ec_lid_angle_ids,
> +};
> +module_platform_driver(cros_ec_lid_angle_platform_driver);
> +
> +MODULE_DESCRIPTION("ChromeOS EC driver for reporting convertible lid angle.");
> +MODULE_LICENSE("GPL v2");
> diff --git a/drivers/mfd/cros_ec_dev.c b/drivers/mfd/cros_ec_dev.c
> index d275deaecb12..11b5b2fd1f33 100644
> --- a/drivers/mfd/cros_ec_dev.c
> +++ b/drivers/mfd/cros_ec_dev.c
> @@ -297,13 +297,17 @@ static void cros_ec_sensors_register(struct cros_ec_dev *ec)
>  
>  	resp = (struct ec_response_motion_sense *)msg->data;
>  	sensor_num = resp->dump.sensor_count;
> -	/* Allocate 1 extra sensors in FIFO are needed */
> -	sensor_cells = kcalloc(sensor_num + 1, sizeof(struct mfd_cell),
> +	/*
> +	 * Allocate extra sensors if lid angle sensor or FIFO are needed.
> +	 */
> +#define NUM_EXTRA_SENSORS 2
> +	sensor_cells = kcalloc(sensor_num + NUM_EXTRA_SENSORS,
> +			       sizeof(struct mfd_cell),
>  			       GFP_KERNEL);
>  	if (sensor_cells == NULL)
>  		goto error;
>  
> -	sensor_platforms = kcalloc(sensor_num + 1,
> +	sensor_platforms = kcalloc(sensor_num,
>  				   sizeof(struct cros_ec_sensor_platform),
>  				   GFP_KERNEL);
>  	if (sensor_platforms == NULL)
> @@ -363,6 +367,11 @@ static void cros_ec_sensors_register(struct cros_ec_dev *ec)
>  		sensor_cells[id].name = "cros-ec-ring";
>  		id++;
>  	}
> +	if (cros_ec_check_features(ec,
> +				EC_FEATURE_REFINED_TABLET_MODE_HYSTERESIS)) {
> +		sensor_cells[id].name = "cros-ec-lid-angle";
> +		id++;
> +	}
>  
>  	ret = mfd_add_devices(ec->dev, 0, sensor_cells, id,
>  			      NULL, 0, NULL);
>
Gwendal Grignou Feb. 28, 2019, 5:41 p.m. UTC | #2 
On Thu, Feb 28, 2019 at 3:18 AM Enric Balletbo i Serra
<enric.balletbo@collabora.com> wrote:
>
> Hi Gwendal,
>
> Thanks to send this upstream.
>
> On 28/2/19 2:50, Gwendal Grignou wrote:
> > Add a IIO driver that reports the angle between the lid and the base for
> > ChromeOS convertible device.
> >
> > Tested on eve with ToT EC firmware.
> > Check driver is loaded and lid angle is correct.
> >
> > Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
> > ---
> >  drivers/iio/common/cros_ec_sensors/Kconfig    |   9 +
> >  drivers/iio/common/cros_ec_sensors/Makefile   |   1 +
> >  .../cros_ec_sensors/cros_ec_lid_angle.c       | 164 ++++++++++++++++++
> >  drivers/mfd/cros_ec_dev.c                     |  15 +-
>
> The mfd/cros_ec_dev.c part looks good to me. I have some few comments in the IIO
> part, see below.
>
> >  4 files changed, 186 insertions(+), 3 deletions(-)
> >  create mode 100644 drivers/iio/common/cros_ec_sensors/cros_ec_lid_angle.c
> >
> > diff --git a/drivers/iio/common/cros_ec_sensors/Kconfig b/drivers/iio/common/cros_ec_sensors/Kconfig
> > index 135f6825903f..aacc2ab9c34f 100644
> > --- a/drivers/iio/common/cros_ec_sensors/Kconfig
> > +++ b/drivers/iio/common/cros_ec_sensors/Kconfig
> > @@ -20,3 +20,12 @@ config IIO_CROS_EC_SENSORS
> >         Accelerometers, Gyroscope and Magnetometer that are
> >         presented by the ChromeOS EC Sensor hub.
> >         Creates an IIO device for each functions.
> > +
> > +config IIO_CROS_EC_SENSORS_LID_ANGLE
> > +     tristate "ChromeOS EC Sensor for lid angle"
> > +     depends on IIO_CROS_EC_SENSORS_CORE
> > +     help
> > +       Module to report the angle between lid and base for some
> > +       convertible devices.
> > +       This module is loaded when the EC can calculate the angle between the base
> > +       and the lid.
> > diff --git a/drivers/iio/common/cros_ec_sensors/Makefile b/drivers/iio/common/cros_ec_sensors/Makefile
> > index ec716ff2a775..a35ee232ac07 100644
> > --- a/drivers/iio/common/cros_ec_sensors/Makefile
> > +++ b/drivers/iio/common/cros_ec_sensors/Makefile
> > @@ -4,3 +4,4 @@
> >
> >  obj-$(CONFIG_IIO_CROS_EC_SENSORS_CORE) += cros_ec_sensors_core.o
> >  obj-$(CONFIG_IIO_CROS_EC_SENSORS) += cros_ec_sensors.o
> > +obj-$(CONFIG_IIO_CROS_EC_SENSORS_LID_ANGLE) += cros_ec_lid_angle.o
> > diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_lid_angle.c b/drivers/iio/common/cros_ec_sensors/cros_ec_lid_angle.c
> > new file mode 100644
> > index 000000000000..370b3e9a1405
> > --- /dev/null
> > +++ b/drivers/iio/common/cros_ec_sensors/cros_ec_lid_angle.c
> > @@ -0,0 +1,164 @@
> > +// SPDX-License-Identifier: GPL-2.0+
> > +
>
> There is a license mismatch between the SPDX identifier (GPLv2 or later) and the
> MODULE_LICENSE (GPLv2). I think that this should be only GPL-2.0
Done.
>
> > +/*
> > + * cros_ec_lid_angle - Driver for CrOS EC lid angle sensor.
> > + *
...
> > +static const struct iio_info cros_ec_lid_angle_info = {
> > +     .read_raw = &cros_ec_lid_angle_read,
> > +     .driver_module = THIS_MODULE,
>
> This is not needed now, you can remove it.
Done.
>
> > +};
> > +
> > +static int cros_ec_lid_angle_probe(struct platform_device *pdev)
...
Lee Jones March 11, 2019, 8:24 a.m. UTC | #3 
On Wed, 27 Feb 2019, Gwendal Grignou wrote:

> Add a IIO driver that reports the angle between the lid and the base for
> ChromeOS convertible device.
> 
> Tested on eve with ToT EC firmware.
> Check driver is loaded and lid angle is correct.
> 
> Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
> ---
>  drivers/iio/common/cros_ec_sensors/Kconfig    |   9 +
>  drivers/iio/common/cros_ec_sensors/Makefile   |   1 +
>  .../cros_ec_sensors/cros_ec_lid_angle.c       | 164 ++++++++++++++++++

>  drivers/mfd/cros_ec_dev.c                     |  15 +-

It doesn't look like there are build dependencies between the changes
in these different subsystems.  If my assumption is correct, please
pull the MFD changes out into a separate patch.

>  4 files changed, 186 insertions(+), 3 deletions(-)
>  create mode 100644 drivers/iio/common/cros_ec_sensors/cros_ec_lid_angle.c

[...]

> diff --git a/drivers/mfd/cros_ec_dev.c b/drivers/mfd/cros_ec_dev.c
> index d275deaecb12..11b5b2fd1f33 100644
> --- a/drivers/mfd/cros_ec_dev.c
> +++ b/drivers/mfd/cros_ec_dev.c
> @@ -297,13 +297,17 @@ static void cros_ec_sensors_register(struct cros_ec_dev *ec)
>  
>  	resp = (struct ec_response_motion_sense *)msg->data;
>  	sensor_num = resp->dump.sensor_count;
> -	/* Allocate 1 extra sensors in FIFO are needed */
> -	sensor_cells = kcalloc(sensor_num + 1, sizeof(struct mfd_cell),
> +	/*
> +	 * Allocate extra sensors if lid angle sensor or FIFO are needed.
> +	 */
> +#define NUM_EXTRA_SENSORS 2

Please refrain from placing #defines in the middle of functions.

Move it to the top of the file.

> +	sensor_cells = kcalloc(sensor_num + NUM_EXTRA_SENSORS,

Actually, this isn't something that needs defining.

Just change the comment to:

  "Allocate 2 extra sensors if lid angle sensor or FIFO are needed."

... and drop the define.

> +			       sizeof(struct mfd_cell),
>  			       GFP_KERNEL);
>  	if (sensor_cells == NULL)
>  		goto error;
>  
> -	sensor_platforms = kcalloc(sensor_num + 1,
> +	sensor_platforms = kcalloc(sensor_num,
>  				   sizeof(struct cros_ec_sensor_platform),
>  				   GFP_KERNEL);
>  	if (sensor_platforms == NULL)
> @@ -363,6 +367,11 @@ static void cros_ec_sensors_register(struct cros_ec_dev *ec)
>  		sensor_cells[id].name = "cros-ec-ring";
>  		id++;
>  	}
> +	if (cros_ec_check_features(ec,
> +				EC_FEATURE_REFINED_TABLET_MODE_HYSTERESIS)) {
> +		sensor_cells[id].name = "cros-ec-lid-angle";
> +		id++;
> +	}
>  
>  	ret = mfd_add_devices(ec->dev, 0, sensor_cells, id,
>  			      NULL, 0, NULL);
diff mbox series

Patch

diff --git a/drivers/iio/common/cros_ec_sensors/Kconfig b/drivers/iio/common/cros_ec_sensors/Kconfig
index 135f6825903f..aacc2ab9c34f 100644
--- a/drivers/iio/common/cros_ec_sensors/Kconfig
+++ b/drivers/iio/common/cros_ec_sensors/Kconfig
@@ -20,3 +20,12 @@  config IIO_CROS_EC_SENSORS
 	  Accelerometers, Gyroscope and Magnetometer that are
 	  presented by the ChromeOS EC Sensor hub.
 	  Creates an IIO device for each functions.
+
+config IIO_CROS_EC_SENSORS_LID_ANGLE
+	tristate "ChromeOS EC Sensor for lid angle"
+	depends on IIO_CROS_EC_SENSORS_CORE
+	help
+	  Module to report the angle between lid and base for some
+	  convertible devices.
+	  This module is loaded when the EC can calculate the angle between the base
+	  and the lid.
diff --git a/drivers/iio/common/cros_ec_sensors/Makefile b/drivers/iio/common/cros_ec_sensors/Makefile
index ec716ff2a775..a35ee232ac07 100644
--- a/drivers/iio/common/cros_ec_sensors/Makefile
+++ b/drivers/iio/common/cros_ec_sensors/Makefile
@@ -4,3 +4,4 @@ 
 
 obj-$(CONFIG_IIO_CROS_EC_SENSORS_CORE) += cros_ec_sensors_core.o
 obj-$(CONFIG_IIO_CROS_EC_SENSORS) += cros_ec_sensors.o
+obj-$(CONFIG_IIO_CROS_EC_SENSORS_LID_ANGLE) += cros_ec_lid_angle.o
diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_lid_angle.c b/drivers/iio/common/cros_ec_sensors/cros_ec_lid_angle.c
new file mode 100644
index 000000000000..370b3e9a1405
--- /dev/null
+++ b/drivers/iio/common/cros_ec_sensors/cros_ec_lid_angle.c
@@ -0,0 +1,164 @@ 
+// SPDX-License-Identifier: GPL-2.0+
+
+/*
+ * cros_ec_lid_angle - Driver for CrOS EC lid angle sensor.
+ *
+ * Copyright 2018 Google, Inc
+ *
+ * This driver uses the cros-ec interface to communicate with the Chrome OS
+ * EC about counter sensors. Counters are presented through
+ * iio sysfs.
+ */
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/common/cros_ec_sensors_core.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/kfifo_buf.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/kernel.h>
+#include <linux/mfd/cros_ec.h>
+#include <linux/mfd/cros_ec_commands.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#define DRV_NAME "cros-ec-lid-angle"
+
+/*
+ * One channel for the lid angle, the other for timestamp.
+ */
+#define MAX_CHANNELS (1 + 1)
+
+/* State data for ec_sensors iio driver. */
+struct cros_ec_lid_angle_state {
+	/* Shared by all sensors */
+	struct cros_ec_sensors_core_state core;
+
+	struct iio_chan_spec channels[MAX_CHANNELS];
+};
+
+static int cros_ec_sensors_read_lid_angle(struct iio_dev *indio_dev,
+					  unsigned long scan_mask, s16 *data)
+{
+	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
+	int ret;
+
+	st->param.cmd = MOTIONSENSE_CMD_LID_ANGLE;
+	ret = cros_ec_motion_send_host_cmd(st, sizeof(st->resp->lid_angle));
+	if (ret) {
+		dev_warn(&indio_dev->dev, "Unable to read lid angle\n");
+		return ret;
+	}
+
+	if (scan_mask & 1)
+		*data = st->resp->lid_angle.value;
+	return 0;
+}
+
+static int cros_ec_lid_angle_read(struct iio_dev *indio_dev,
+				    struct iio_chan_spec const *chan,
+				    int *val, int *val2, long mask)
+{
+	struct cros_ec_lid_angle_state *st = iio_priv(indio_dev);
+	u16 data;
+	int ret;
+	int idx = chan->scan_index;
+
+	mutex_lock(&st->core.cmd_lock);
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		ret = cros_ec_sensors_read_lid_angle(
+				indio_dev, 1 << idx, &data);
+		if (ret)
+			break;
+		ret = IIO_VAL_INT;
+		*val = data;
+		break;
+	default:
+		ret = -EINVAL;
+	}
+	mutex_unlock(&st->core.cmd_lock);
+	return ret;
+}
+
+static const struct iio_info cros_ec_lid_angle_info = {
+	.read_raw = &cros_ec_lid_angle_read,
+	.driver_module = THIS_MODULE,
+};
+
+static int cros_ec_lid_angle_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct iio_dev *indio_dev;
+	struct cros_ec_lid_angle_state *state;
+	struct iio_chan_spec *channel;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*state));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	ret = cros_ec_sensors_core_init(pdev, indio_dev, false);
+	if (ret)
+		return ret;
+
+	indio_dev->info = &cros_ec_lid_angle_info;
+	state = iio_priv(indio_dev);
+	channel = state->channels;
+
+	channel->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
+	channel->scan_type.realbits = CROS_EC_SENSOR_BITS;
+	channel->scan_type.storagebits = CROS_EC_SENSOR_BITS;
+	channel->scan_type.shift = 0;
+	channel->scan_index = 0;
+	channel->scan_type.sign = 'u';
+	channel->type = IIO_ANGL;
+
+	state->core.calib[0] = 0;
+
+	/* Timestamp */
+	channel++;
+	channel->type = IIO_TIMESTAMP;
+	channel->channel = -1;
+	channel->scan_index = 1;
+	channel->scan_type.sign = 's';
+	channel->scan_type.realbits = 64;
+	channel->scan_type.storagebits = 64;
+
+	indio_dev->channels = state->channels;
+	indio_dev->num_channels = MAX_CHANNELS;
+
+	state->core.read_ec_sensors_data = cros_ec_sensors_read_lid_angle;
+
+	ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
+			cros_ec_sensors_capture, NULL);
+	if (ret)
+		return ret;
+
+	return devm_iio_device_register(dev, indio_dev);
+}
+
+static const struct platform_device_id cros_ec_lid_angle_ids[] = {
+	{
+		.name = DRV_NAME,
+	},
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(platform, cros_ec_lid_angle_ids);
+
+static struct platform_driver cros_ec_lid_angle_platform_driver = {
+	.driver = {
+		.name	= DRV_NAME,
+		.pm	= &cros_ec_sensors_pm_ops,
+	},
+	.probe		= cros_ec_lid_angle_probe,
+	.id_table	= cros_ec_lid_angle_ids,
+};
+module_platform_driver(cros_ec_lid_angle_platform_driver);
+
+MODULE_DESCRIPTION("ChromeOS EC driver for reporting convertible lid angle.");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/mfd/cros_ec_dev.c b/drivers/mfd/cros_ec_dev.c
index d275deaecb12..11b5b2fd1f33 100644
--- a/drivers/mfd/cros_ec_dev.c
+++ b/drivers/mfd/cros_ec_dev.c
@@ -297,13 +297,17 @@  static void cros_ec_sensors_register(struct cros_ec_dev *ec)
 
 	resp = (struct ec_response_motion_sense *)msg->data;
 	sensor_num = resp->dump.sensor_count;
-	/* Allocate 1 extra sensors in FIFO are needed */
-	sensor_cells = kcalloc(sensor_num + 1, sizeof(struct mfd_cell),
+	/*
+	 * Allocate extra sensors if lid angle sensor or FIFO are needed.
+	 */
+#define NUM_EXTRA_SENSORS 2
+	sensor_cells = kcalloc(sensor_num + NUM_EXTRA_SENSORS,
+			       sizeof(struct mfd_cell),
 			       GFP_KERNEL);
 	if (sensor_cells == NULL)
 		goto error;
 
-	sensor_platforms = kcalloc(sensor_num + 1,
+	sensor_platforms = kcalloc(sensor_num,
 				   sizeof(struct cros_ec_sensor_platform),
 				   GFP_KERNEL);
 	if (sensor_platforms == NULL)
@@ -363,6 +367,11 @@  static void cros_ec_sensors_register(struct cros_ec_dev *ec)
 		sensor_cells[id].name = "cros-ec-ring";
 		id++;
 	}
+	if (cros_ec_check_features(ec,
+				EC_FEATURE_REFINED_TABLET_MODE_HYSTERESIS)) {
+		sensor_cells[id].name = "cros-ec-lid-angle";
+		id++;
+	}
 
 	ret = mfd_add_devices(ec->dev, 0, sensor_cells, id,
 			      NULL, 0, NULL);