iio: core: Introduce IIO_CHAN_INFO_DEBOUNCE_COUNT and _TIME

The pedometer needs to filter out false steps that might be generated by
tapping the foot, sitting, etc. To do that it computes the number of
steps that occur in a given time and decides the user is moving only
if this value is over a threshold. E.g.: the user starts moving only
if he takes 4 steps in 3 seconds. This filter is applied only when
the user starts moving.

A device that has such pedometer functionality is Freescale's MMA9553L:
http://www.freescale.com/files/sensors/doc/ref_manual/MMA9553LSWRM.pdf.

To export this feature, this patch introduces IIO_CHAN_INFO_DEBOUNCE_COUNT
and IIO_CHAN_INFO_DEBOUNCE_TIME. For the pedometer, in_steps_debounce_count
will specify the number of steps that need to occur in
in_steps_debounce_time seconds so that the pedometer decides the user is
moving.

Signed-off-by: Irina Tirdea <irina.tirdea@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio
index c03a1401b9ca131d0509306e829efbd7790b293d..b4ea9c521f6995d6e152043506d6213e88f01a61 100644 (file)
--- a/Documentation/ABI/testing/sysfs-bus-iio
+++ b/Documentation/ABI/testing/sysfs-bus-iio
@@ -1193,3 +1193,18 @@ Description:
                This attribute is used to read the current speed value of the
                user (which is the norm or magnitude of the velocity vector).
                Units after application of scale are m/s.
+
+What:          /sys/.../iio:deviceX/in_steps_debounce_count
+KernelVersion: 3.20
+Contact:       linux-iio@vger.kernel.org
+Description:
+               Specifies the number of steps that must occur within
+               in_steps_filter_debounce_time for the pedometer to decide the
+               consumer is making steps.
+
+What:          /sys/.../iio:deviceX/in_steps_debounce_time
+KernelVersion: 3.20
+Contact:       linux-iio@vger.kernel.org
+Description:
+               Specifies number of seconds in which we compute the steps
+               that occur in order to decide if the consumer is making steps.

diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index 4ee6fdfa92fe75f4e9c179cc6b0ca2801010d7a5..aaba9d3d980ee623ad6b78111a9c9708198b23e0 100644 (file)
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -126,6 +126,8 @@ static const char * const iio_chan_info_postfix[] = {
        [IIO_CHAN_INFO_ENABLE] = "en",
        [IIO_CHAN_INFO_CALIBHEIGHT] = "calibheight",
        [IIO_CHAN_INFO_CALIBWEIGHT] = "calibweight",
+       [IIO_CHAN_INFO_DEBOUNCE_COUNT] = "debounce_count",
+       [IIO_CHAN_INFO_DEBOUNCE_TIME] = "debounce_time",
 };
 
 /**

diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h
index 51f16437dacc7998a5252211827873bdeaad4098..80d8550610646fdc25aef65d93efde6ae9343341 100644 (file)
--- a/include/linux/iio/iio.h
+++ b/include/linux/iio/iio.h
@@ -41,6 +41,8 @@ enum iio_chan_info_enum {
        IIO_CHAN_INFO_ENABLE,
        IIO_CHAN_INFO_CALIBHEIGHT,
        IIO_CHAN_INFO_CALIBWEIGHT,
+       IIO_CHAN_INFO_DEBOUNCE_COUNT,
+       IIO_CHAN_INFO_DEBOUNCE_TIME,
 };
 
 enum iio_shared_by {