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

[Daniel Baluta <daniel.baluta@intel.com>]

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>
---
 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 {
-- 
1.9.1