Re: [RFC PATCH 4/8] iio: core: Introduce pedometer STEP counter modifier

[Jonathan Cameron <jic23@kernel.org>]

On 02/10/14 14:43, Daniel Baluta wrote:
> From: Irina Tirdea <irina.tirdea@intel.com>
> 
> One of the functionalities of a pedometer is a step counter.
> The step counter needs to be enabled and then it will count the steps
> in its hardware register. Whenever the applications need to check
> the step count, they will read the step counter register.
> 
> To support this functionality we need a steps attribute that
> will export the number of steps.
> 
> For more information on the pedometer requirements for Android see
> http://source.android.com/devices/sensors/composite_sensors.html#counter.
> 
> A device that has the pedometer functionality this interface needs to
> support is Freescale's MMA9553L:
> http://www.freescale.com/files/sensors/doc/ref_manual/MMA9553LSWRM.pdf
> 
> Signed-off-by: Irina Tirdea <irina.tirdea@intel.com>
> Signed-off-by: Daniel Baluta <daniel.baluta@intel.com>
I'm not keen on multiplexing different types of data onto a single activity type.
Steps is well enough defined on it's own to have it's own channel type.

in_steps_input would be fine by me.  I suppose steps might mean something else
though...

> ---
>  Documentation/ABI/testing/sysfs-bus-iio | 7 +++++++
>  drivers/iio/industrialio-core.c         | 1 +
>  include/linux/iio/types.h               | 1 +
>  3 files changed, 9 insertions(+)
> 
> diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio
> index 070346d..feacb45 100644
> --- a/Documentation/ABI/testing/sysfs-bus-iio
> +++ b/Documentation/ABI/testing/sysfs-bus-iio
> @@ -949,6 +949,13 @@ Description:
>  		and the relevant _type attributes to establish the data storage
>  		format.
>  
> +What:		/sys/.../iio:deviceX/in_activity_steps_raw
> +KernelVersion:	3.17
> +Contact:	linux-iio@vger.kernel.org
> +Description:
> +		This attribute is used to read the number of steps taken by the user
> +		since the last reboot while activated.
> +
>  What:		/sys/.../iio:deviceX/in_anglvel_z_quadrature_correction_raw
>  KernelVersion:	2.6.38
>  Contact:	linux-iio@vger.kernel.org
> diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
> index e453ef9..935a8a1 100644
> --- a/drivers/iio/industrialio-core.c
> +++ b/drivers/iio/industrialio-core.c
> @@ -96,6 +96,7 @@ static const char * const iio_modifier_names[] = {
>  	[IIO_MOD_JOGGING] = "jogging",
>  	[IIO_MOD_WALKING] = "walking",
>  	[IIO_MOD_STILL] = "still",
> +	[IIO_MOD_PED_STEPS] = "steps",
>  };
>  
>  /* relies on pairs of these shared then separate */
> diff --git a/include/linux/iio/types.h b/include/linux/iio/types.h
> index 003638d..ae51780 100644
> --- a/include/linux/iio/types.h
> +++ b/include/linux/iio/types.h
> @@ -65,6 +65,7 @@ enum iio_modifier {
>  	IIO_MOD_JOGGING,
>  	IIO_MOD_WALKING,
>  	IIO_MOD_STILL,
> +	IIO_MOD_PED_STEPS,
>  };
>  
>  enum iio_event_type {
>