Re: [RFC 4/4] iio: trigger: add GPIO trigger

From: Fabrice Gasnier
Date: Mon Feb 20 2017 - 11:25:28 EST

On 02/18/2017 08:19 PM, Jonathan Cameron wrote:
On 17/02/17 16:16, Lars-Peter Clausen wrote:
On 02/17/2017 05:03 PM, Fabrice Gasnier wrote:
GPIOs can be used to generate triggers for any IIO device.
Introduce generic GPIO trigger driver. It offers some options
to tune polarity (e.g. rising/falling edge), and label so trigger
name may be customized.
By default, gpio triggers will be named gpiotrigX, where X is gpio
number as returned by desc_to_gpio() call.
Rising edge is selected if polarity isn't set.

If you want to use the GPIO only as an interrupt, just use it as an
interrupt directly, no need to go the route via the GPIO.
Absolutely. The majority of the bindings will then just become standard
interrupt bindings and will be effectively handled for you.

Please work to extend the existing interrupt trigger driver rather than adding
this new one. That one actually started as a gpio trigger then got
generalised into a interrupt trigger later so lets not do that again ;)

Hi Lars, Jonathan

Ok, got it.
I'll drop this and focus on interrupt trigger, if this is worth having DT for it (e.g. patch 1 & 2 of this RFC).

BTW, I figured out there has been this patch a year ago, on interrupt trigger, to add device tree support:
Any reason why it hasn't found its way in ?

Thanks for reviewing,
Best Regards,