On Tue, Apr 14, 2020 at 1:48 PM William Breathitt Gray <vilhelm.gray@xxxxxxxxx> wrote: > > On Mon, Apr 13, 2020 at 12:55:14PM -0700, Gwendal Grignou wrote: > > When the camera vsync pin is connected to the embedded controller (EC) of > > a chromebook, the EC reports a sensor with a counter that increases > > at each GPIO rising edge. > > > > The sensor is presented using the counter subsystem. > > In addition, it is also presented via the IIO subsystem with a timestamp, > > allowing synchronisation with sensors connected to the same EC, for > > image stabilisation or augmented reality applications. > > Hi Gwendal, > > Sorry for the delay. I have some changes requested below. > > > To enable the counter: > > via counter ABI: > > echo "rising edge" > counterX/count0/signal_action > > via iio ABI > > echo 1 > iio:deviceY/en > > > > To disable the counter: > > via counter ABI: > > echo "none" > counterX/count0/signal_action > > via iio ABI > > echo 0 > iio:deviceY/en > > Although in theory a user could manually disable the actions for a > Signal, this is a very roundabout way of actually disabling the Count. > It's better to expose an "enable" attribute to allow the users to > perform this functionality; for example: > > echo 0 > counterX/count0/enable > echo 1 > counterX/count0/enable > > > > > To read the current counter value: > > via counter ABI: > > cat counterX/count0/count > > via iio ABI > > cat iio:deviceY/in_count_raw > > I know we discussed this in the last review but it's still the same as > before: IIO_COUNT interface is deprecated so new drivers won't be > allowed to use it. You'll have to remove the IIO_COUNT code in this > driver and replace it with Counter subsystem equivalents. I understand the need of a clean separation between counter and IIO subsystems. I will wait for counter to offer a way to gather timestamp'ed counts. Do you have a plan/proposed ABI you can share? Thanks, Gwendal.
