Re: [PATCH v2 2/2] iio: Add linear accel sensor hid support

[Jonathan Cameron <jic23-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>]

On 05/01/17 11:03, Song Hongyan wrote:
> Linear acceleration is a soft sensor it differs from a standard
> accel sensor, it provides a three-dimensional vector representing
> acceleration along each device axis, excluding gravity.
> The sensor data is derives from standard accelerometer device
> by filtering out the acceleration which is caused by the force
> of Earth’s gravity.
> 
> The value can be used to perform gesture detection, it can also
> serve as input to an inertial navigation system, which uses
> dead reckoning.
> 
> More information can be found in:
> http://www.usb.org/developers/hidpage/HUTRR59_-_Usages_for_Wearables.pdf
> 
> Linear accel sensor, gravity sensor and accelerometer have similar
> channels and share channel usage ids. So the most of the code for
> accel_3d can be reused.
> 
> Signed-off-by: Song Hongyan <hongyan.song-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Applied to the togreg branch of iio.git - initially pushed out as testing sometime soonish.

Thanks,

Jonathan
> ---
> changes: unify name not use underline as separator.
> 
>  drivers/iio/accel/hid-sensor-accel-3d.c | 42 +++++++++++++++++++++++++++++++++
>  include/linux/hid-sensor-ids.h          |  3 +++
>  2 files changed, 45 insertions(+)
> 
> diff --git a/drivers/iio/accel/hid-sensor-accel-3d.c b/drivers/iio/accel/hid-sensor-accel-3d.c
> index 9edd574..8829dad 100644
> --- a/drivers/iio/accel/hid-sensor-accel-3d.c
> +++ b/drivers/iio/accel/hid-sensor-accel-3d.c
> @@ -91,6 +91,41 @@ struct accel_3d_state {
>  };
>  
>  /* Channel definitions */
> +static const struct iio_chan_spec linearaccel_3d_channels[] = {
> +	{
> +		.type = IIO_LINEARACCEL,
> +		.modified = 1,
> +		.channel2 = IIO_MOD_X,
> +		.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_index = CHANNEL_SCAN_INDEX_X,
> +	}, {
> +		.type = IIO_LINEARACCEL,
> +		.modified = 1,
> +		.channel2 = IIO_MOD_Y,
> +		.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_index = CHANNEL_SCAN_INDEX_Y,
> +	}, {
> +		.type = IIO_LINEARACCEL,
> +		.modified = 1,
> +		.channel2 = IIO_MOD_Z,
> +		.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_index = CHANNEL_SCAN_INDEX_Z,
> +	}
> +};
> +
> +/* Channel definitions */
>  static const struct iio_chan_spec gravity_channels[] = {
>  	{
>  		.type = IIO_GRAVITY,
> @@ -354,6 +389,10 @@ static int hid_accel_3d_probe(struct platform_device *pdev)
>  		name = "accel_3d";
>  		channel_spec = accel_3d_channels;
>  		channel_size = sizeof(accel_3d_channels);
> +	} else if (hsdev->usage == HID_USAGE_SENSOR_LINEARACCEL_3D) {
> +		name = "linearaccel_3d";
> +		channel_spec = linearaccel_3d_channels;
> +		channel_size = sizeof(linearaccel_3d_channels);
>  	} else {
>  		name = "gravity";
>  		channel_spec = gravity_channels;
> @@ -452,6 +491,9 @@ static int hid_accel_3d_remove(struct platform_device *pdev)
>  	{	/* gravity sensor */
>  		.name = "HID-SENSOR-20007b",
>  	},
> +	{	/* linear_accel sensor */
> +		.name = "HID-SENSOR-20007c",
> +	},
>  	{ /* sentinel */ }
>  };
>  MODULE_DEVICE_TABLE(platform, hid_accel_3d_ids);
> diff --git a/include/linux/hid-sensor-ids.h b/include/linux/hid-sensor-ids.h
> index b6778fd2..bab8375 100644
> --- a/include/linux/hid-sensor-ids.h
> +++ b/include/linux/hid-sensor-ids.h
> @@ -55,6 +55,9 @@
>  /* Gravity vector */
>  #define HID_USAGE_SENSOR_GRAVITY_VECTOR				0x20007B
>  
> +/* linear accel */
> +#define HID_USAGE_SENSOR_LINEARACCEL_3D			0x20007C
> +
>  /* ORIENTATION: Compass 3D: (200083) */
>  #define HID_USAGE_SENSOR_COMPASS_3D				0x200083
>  #define HID_USAGE_SENSOR_DATA_ORIENTATION			0x200470
>