iio: core: Introduce IIO_ACTIVITY channel
This channel will be used for exposing information about
activity composite sensors. Activities supported so far:
* running
* jogging
* walking
* still
THRESHOLD event is used to signal a change in the activity
state.
We associate a confidence interval for each activity expressed
as a percentage from 0 to 100.
* 0, means the sensor IS NOT reporting that activity.
* 100, means the sensor IS reporting that activity.
Users of this interface have two possible means to gather
information about the ongoing activities.
1. Event based, via event file descriptor
* sensor may report an event when ENTERING an activity or LEAVING
an activity based on a threshold value.
* drivers will wake up applications waiting data on the event fd
2. Polling, by reading the sysfs associated attribute files:
* /sys/bus/iio/devices/iio:device0/in_activity_running_input
expressed as percentage confidence value from 0 to 100.
This will offer an interface for Android significant motion
composite sensor defined here:
http://source.android.com/devices/sensors/composite_sensors.html
Activities listed above are supported by Freescale's MMA9553 sensor:
http://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>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
3 files changed