Re: Handling Controllers with Acc/Gyro/Mag via HID system

On Mon, 2015-06-08 at 22:38 -0400, simon-wM4F9T/ekXmXDw4h08c5KA@public.gmane.org wrote:

quoted

Hi all,
I'm in the process of fixing the HID descriptor for the PS3 Move

Controller. which has a particularly convoluted layout for it's

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Accelormeters, Gyros and Magnetometers involving 2 sets of data per 
output
report.
https://github.com/nitsch/moveonpc/wiki/Input-report

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The plan is/was to massage the HID descriptor so the first set of

Accels/Gyro/Mag appear in a set a axis, as a simple way of getting to
this

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data.

[snip]

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Given that more controllers are coming with 'motion' controls, is 
there a
framework in place for unifying support?

A little more poking around has got me looking at the IIO subsystem, 
which
seems to be everything Accel/Gyro/Mag...

The IIO subsystem's user-space API is awful, and root only. I said as
much here:
http://thread.gmane.org/gmane.linux.kernel.iio/14421

I note that there are a few 'HID'ish things there too, although I'm 
not
sure whether they are useful to us, or just intended for connecting 
motion
devices via the HID bus and then onto IIO.
--
drivers/iio/accel/hid-sensor-accel-3d.c
drivers/iio/gyro/hid-sensor-gyro-3d.c
drivers/iio/magnetometer/hid-sensor-magn-3d.c
drivers/iio/orientation/hid-sensor-rotation.c
--

Does the idea of the drivers for the HID (gaming) controllers opening 
up a
connection to IIO system and pushing the Accel/Gyro/Mag values there
(rather than exposing them on the joystick interface) make sense?

Are there any examples of other devices doing this, so I can re-use 
the code?

I wrote this for accelerometers that are in tablets/convertibles:
https://github.com/hadess/iio-sensor-proxy/