[alsa-devel] Headset button mapping in the kernel

[Curtis Malainey]

On Wed, Nov 27, 2019 at 4:01 AM Takashi Iwai <tiwai at suse.de> wrote:
>
> On Mon, 25 Nov 2019 20:25:53 +0100,
> Curtis Malainey wrote:
> >
> > Hello ALSA Devs,
> >
> > I am looking to get some feedback/ideas on a possible change to
> > headset button mapping. Locally we are carrying patches that implement
> > the mappings in the machine driver (which we understand you do not
> > want upstream.) We are looking to see if we can add a new API
> > (something like a sysfs path potentially) to have userspace pass in
> > the mapping, if it chooses to, so the mapping can still be done in the
> > kernel. That way we can carry just the config locally and remove some
> > of the kernel patches we are carrying locally. Thanks.
>
> I guess you're referring to the mapping that is currently done via
> snd_jack_set_key() calls?  If so, an additional sysfs or such
> interface would be handy, and it should be relatively easy.
Yes this is what I was thinking.
>
> But a proper sysfs entry design is another question; it's an array,
> and this can be set for each jack object, so not that trivial.
Agreed, it will likely take some work, but it is good to know you are
open to the idea. I can start looking at some possible designs and
share them here. Hopefully will have them in the next week or two.
>
>
> thanks,
>
> Takashi