On Thu, Jun 17, 2021 at 01:19:05PM +0000, Shuming [范書銘] wrote:

> > > This patch uses the same mapping as the machine driver:
> > > BTN_0 : KEY_PLAYPAUSE
> > > BTN_1 : KEY_VOICECOMMAND
> > > BTN_2 : KEY_VOLUMEUP
> > > BTN_3 : KEY_VOLUMEDOWN

> > Which machine driver?  Can't there be multiple machine drivers, and if
> > they're already overriding things why do this?

> The rt711 codec is designed in the Intel platform only for now.

I'm sure your sales team would be happy to change that!

> The machine driver is 'sof_sdw.c' that resides under sound/soc/intel/boards.
> It seems Intel uses the same mapping in all other Intel machine drivers.
> Please check the commit as below.
> https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git/commit/?id=1f64a08bd5a9a218deb37c03c1e98e9567379698

Sure, but if the machine drivers for these platforms already do the
right thing why change the CODEC driver?

> Hi Sathya,
> Do you know why the m/c driver uses this mapping?

I'd guess it's just because that's the standard set of headphone buttons
that Intel uses for their platforms.