Re: [PATCH] ASoC: rt722-sdca: add FU06 Playback Switch for speaker mute control

[Pierre-Louis Bossart]

On 4/24/26 17:53, Charles Keepax wrote:
> On Fri, Apr 24, 2026 at 03:09:10PM +0200, Pierre-Louis Bossart wrote:
>> On 4/24/26 05:52, Aaron Ma wrote:
>>> On Thu, Apr 23, 2026 at 9:01 PM Pierre-Louis Bossart
>>> <pierre-louis.bossart@xxxxxxxxx> wrote:
>>>> On 4/23/26 12:13, Aaron Ma wrote:
>> While I am at it, in theory those registers are Dual-Ranked,
>> with a 'commit' mechanism to deal with all volume changes
>> at the same time. We'll need to add support for Dual-Ranked
>> registers at some point, not sure how this can be bolted in
>> regmap support... Cc: Charles for future SDCA improvements...
> 
> Eek... *hides in dark corner*. Yeah at some point we do need
> to do some thinking about dual ranked controls, at the moment
> there is no support. As far as my thinking got was really it
> is in a lot of situations hard to tell which writes you want
> to group. There is some low hanging fruit, for example stereo
> volumes would make sense to group if dual ranked. Although in
> those cases I tend to see user-space changing the volumes one
> channel at a time anyway. And that is even before you get to the
> regmap implementation details which is foggy at best in my mind.
> 
> Sorry I don't have more, it is loosely on my virtual todo list,
> but definitely not something I have got around to thinking
> through yet.

Yeah I can't say I have a good view either...

In theory at the Function level there is a Commit Group mask, a Function can be a member of multiple groups.
The fun part is this statement in the spec

"This Control selects the Commit Group(s) which contain every dual-ranked Control within this Function."

but then the SoundWire spec says

"Every Dual-Ranked Register is associated with one or more of 7 Commit Groups"

interesting wording, I am in the dark on how we would know which controls are part of which Commit Group.

And then IIRC there was a desire to update volume controls on multiple devices, e.g. if there are multiple amps the volumes would be updated across devices.
Not sure how to achieve this...