Re: [RFC 0/4] iio: trigger: Add OF support and GPIO based trigger

[Daniel Baluta]

On Fri, Feb 17, 2017 at 6:03 PM, Fabrice Gasnier <fabrice.gasnier@xxxxxx> wrote:
> Hi,
>
> I send this as an RFC, as I'm digging to try to get as generic
> as possible GPIO based trigger support, as discussed earlier in
> other patchset "Add EXTI GPIO trigger support to STM32 ADC":
> https://www.spinics.net/lists/arm-kernel/msg559091.html
>
> Following various comments on this, I sent this RFC to address two
> topics, that I see as possible prerequisite:
> - Add trigger OF support
> - GPIO based trigger

I wonder if we could use configfs to create and configure
a GPIO based trigger.

You should just create another trigger type (look into
drivers/iio/trigger/iio-trig-hrtimer.c)
the userspace API will look like this:

# cd /config/iio/triggers
# insert your iio-trig-gpio
# setup the global parameters for the GPIO (the local params can be
set via dts/acpi)
# cd /config/iio/trigers/gpios/

#mkdir t1

And this will create an io-gpio-trigger named t1.

Not sure this fits your usecase but would be nice to consider.

thanks,
Daniel.