Re: [PATCH 1/2] Input: gpio_keys - Also send release events for ABS codes

From: Dmitry Torokhov
Date: Tue Nov 08 2016 - 19:09:59 EST


On Sat, Nov 05, 2016 at 12:58:00PM +0100, Paul Cercueil wrote:
> On 03/11/2016 17:21, Dmitry Torokhov wrote:
> >On Tue, Nov 01, 2016 at 11:25:03AM +0100, Paul Cercueil wrote:
> >>Right now, the gpio-keys driver is mostly used with EV_KEY event types.
> >>However, this driver (and its devicetree bindings) support specifying
> >>a different input type, like EV_ABS, even though this doesn't work in
> >>practice: "key pressed" events are correctly received and treated, but
> >>"key released" are silently ignored.
> >>
> >>With this commit, keys configured as EV_ABS will inject an event with
> >>the value 0 when released.
> >No, this will break setups like this:
> >
> >gpio0 - ABS_X - 0
> >gpio1 - ABS_X - 1
> >gpio2 - ABS_X - 2
> >...
> >gpio7 - ABS_X - 7
> >
> >- something like a slider built on top of gpios.
>
> So what would you suggest for the implementation of a hat / d-pad on
> top of GPIOs?

Maybe we should allow specifying "release" value for ABS GPIOs.

Thanks.

--
Dmitry