[RFP] iio: Support of gesture sensor as a standard IIO sensor

[Pandruvada, Srinivas]

Hi Jonathan and Everyone,

The Intel Integrated sensor hub (ISH) on some platforms have ability to
identify gestures. This is available on some Android platforms. We want
to bring in this capability to other Linux flavors also.Â

This algorithm for gesture recognition executes in ISH as this is a
computation intensive and need to be running even when the main
platform CPU goes to sleep.

We already have ISH support available in upstream Linux for a while.
The standard sensors in ISH like Accelerometer, Gyro, ALS etc already
exposed via Linux IIO. Several Laptops and 2-in-1s already using some
features like screen rotation, auto back light adjustment etc. We can
also add gestures. For example
-device wake up from deep power save state once device is picked up
-User can send device to sleep by simple hand gestures
-Some games can utilize gestures to be more user friendly	

The proposal here is to expose gesture sensor via standard IIO
interface.

A typical gesture recognition process involves:

Raw Data -> Preprocessing -> Feature Extraction -> Template match ->
Matched activity

This processing is done in ISH. Intel provides a content sensing SDK
[1] to develop applications. There are already some standard gestures
patterns already in built in the ISH for Android devices. The SDK
documentation provides details about them. Also there are user defined
gestures which essentially are templates for matching and needs to be
downloaded to ISH.

From an IIO sensor point of view A Gesture sensor:
Outputs
	A pre defined activity type
		WAKE
		TILT
		GLANCE
		PICK_UP
		Â&
		Âmore

	A user defined activity type as "string"

Inputs
	A raw binary cdev interface to download templates/patterns


I want to gather more opinions before submitting a RFC patch.

References
1. https://software.intel.com/en-us/documentation/context-sensing-sdk-f
or-android-developer-guide
2. https://software.intel.com/en-us/documentation/using-gesture-recogni
tion-as-differentiation-feature-on-android

Thanks,
Srinivas