[PATCH 2/2] Input: Adding DT support for keyreset tuneables

Mathieu Poirier mathieu.poirier at linaro.org
Thu Jul 11 07:35:25 EST 2013


On 10 July 2013 10:52, Dmitry Torokhov <dmitry.torokhov at gmail.com> wrote:

> On Wed, Jul 10, 2013 at 04:14:57PM +0100, Grant Likely wrote:
> > On Fri, 28 Jun 2013 07:19:06 -0600, Mathieu Poirier <
> mathieu.poirier at linaro.org> wrote:
> > > On 13-06-28 12:09 AM, Dmitry Torokhov wrote:
> > > >>>> I do not agree.  We want the binding to be generic and not tied
> > > >>>> specifically to the keyreset functionality.  As such
> 'input-keyset' or
> > > >>>> 'input-keychord' are more appropriate.
> > > >>>
> > > >>> The binding is defined specifically for sysrq and specifically to
> > > >>> perform reset action.
> > > >>
> > > >> Yes for now but as the examples in the binding show, it is easy to
> > > >> envision how other drivers could use it.
> > > >
> > > > I think you over-complicate things here. Unlike matrix-keypad
> binding,
> > > > where you have a common parsing code, here we have an individual
> driver.
> > > > I really do not see anyone else using such sequences or chords as
> such
> > > > processing should be done in userspace. Sysrq is quite an exception.
> > >
> > > To be honest I don't have a very strong opinion on the binding.  I made
> > > it as generic as possible on the guidance of the DT people.  Let's see
> > > what they think of it.
> >
> > Hi Mathieu,
> >
> > As per our conversation just now at Connect, the binding should probably
> > look like this:
> >
> > Sysrq keyset binding:
> >
> > The /chosen node can contain a linux,input-keyset-sysrq child node to
> > define a set of keys that will generate a sysrq when pressed together.
>
> Hmm, we would have only one such node, /sysrq, or /linux,sysrq,
> whatever. The sysrq setting is system-wide and applicable to all
> devices. Given that it is used only on mobile, where there not that
> many input devices (a few keys and touchscreen) I do not believe we
> should consider adding per-device settings.
>

Putting the binding in the "chosen" node is definitely a system wide
setting.  If I didn't interpret your comment properly, please get back to
me.


>
> >
> > Required properties:
> > keyset: array of keycodes
>
> Please, let's call it 'key-reset-seq', because it is exactly the reset
> sequence. There won't be any additional sequences or chords as those
> should be handled in userspace, sysrq is a special case here.
>


I'm not strongly opinionated on that front but I think it should, at least,
include the some clue about the driver it ties to.  What do you think
about: "linux,sysrq-reset-seq" ?


> > timeout-ms: duration keys must be pressed together in microseconds
> > before generating a sysrq
> >
>
> Thanks.
>
> --
> Dmitry
>
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