iio: core: Introduce CHANGE event type

A step detector will generate an interrupt each time N step are detected.
A device that has such pedometer functionality is Freescale's MMA9553L:
http://www.freescale.com/files/sensors/doc/ref_manual/MMA9553LSWRM.pdf.

Introduce IIO_EV_TYPE_CHANGE event type for events that are generated
when the channel passes a threshold on the absolute change in value.

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 71dc8db..c03a140 100644 (file)
--- a/Documentation/ABI/testing/sysfs-bus-iio
+++ b/Documentation/ABI/testing/sysfs-bus-iio
@@ -891,12 +891,24 @@ Description:
                number or direction is not specified, applies to all channels of
                this type.
 
-What:          /sys/.../events/in_steps_instance_en
-KernelVersion: 3.19
+What:          /sys/.../events/in_steps_change_en
+KernelVersion: 3.20
 Contact:       linux-iio@vger.kernel.org
 Description:
-               Enables or disables step detection. Each time the user takes a step an
-               event of this type will be generated.
+               Event generated when channel passes a threshold on the absolute
+               change in value. E.g. for steps: a step change event is
+               generated each time the user takes N steps, where N is set using
+               in_steps_change_value.
+
+What:          /sys/.../events/in_steps_change_value
+KernelVersion: 3.20
+Contact:       linux-iio@vger.kernel.org
+Description:
+               Specifies the value of change threshold that the
+               device is comparing against for the events enabled by
+               <type>[Y][_name]_roc[_rising|falling|]_en. E.g. for steps:
+               if set to 3, a step change event will be generated every 3
+               steps.
 
 What:          /sys/bus/iio/devices/iio:deviceX/trigger/current_trigger
 KernelVersion: 2.6.35

diff --git a/drivers/iio/industrialio-event.c b/drivers/iio/industrialio-event.c
index 78cf115..b33ce55 100644 (file)
--- a/drivers/iio/industrialio-event.c
+++ b/drivers/iio/industrialio-event.c
@@ -198,6 +198,7 @@ static const char * const iio_ev_type_text[] = {
        [IIO_EV_TYPE_THRESH_ADAPTIVE] = "thresh_adaptive",
        [IIO_EV_TYPE_MAG_ADAPTIVE] = "mag_adaptive",
        [IIO_EV_TYPE_INSTANCE] = "instance",
+       [IIO_EV_TYPE_CHANGE] = "change",
 };
 
 static const char * const iio_ev_dir_text[] = {

diff --git a/drivers/staging/iio/Documentation/iio_event_monitor.c b/drivers/staging/iio/Documentation/iio_event_monitor.c
index def236a..2e78d58 100644 (file)
--- a/drivers/staging/iio/Documentation/iio_event_monitor.c
+++ b/drivers/staging/iio/Documentation/iio_event_monitor.c
@@ -60,6 +60,7 @@ static const char * const iio_ev_type_text[] = {
        [IIO_EV_TYPE_THRESH_ADAPTIVE] = "thresh_adaptive",
        [IIO_EV_TYPE_MAG_ADAPTIVE] = "mag_adaptive",
        [IIO_EV_TYPE_INSTANCE] = "instance",
+       [IIO_EV_TYPE_CHANGE] = "change",
 };
 
 static const char * const iio_ev_dir_text[] = {
@@ -179,6 +180,7 @@ static bool event_is_known(struct iio_event_data *event)
        case IIO_EV_TYPE_THRESH_ADAPTIVE:
        case IIO_EV_TYPE_MAG_ADAPTIVE:
        case IIO_EV_TYPE_INSTANCE:
+       case IIO_EV_TYPE_CHANGE:
                break;
        default:
                return false;

diff --git a/include/linux/iio/types.h b/include/linux/iio/types.h
index c3601c2..3ba3d66 100644 (file)
--- a/include/linux/iio/types.h
+++ b/include/linux/iio/types.h
@@ -79,6 +79,7 @@ enum iio_event_type {
        IIO_EV_TYPE_THRESH_ADAPTIVE,
        IIO_EV_TYPE_MAG_ADAPTIVE,
        IIO_EV_TYPE_INSTANCE,
+       IIO_EV_TYPE_CHANGE,
 };
 
 enum iio_event_info {