[alsa-devel] [PATCH 1/2] ASoC: add generic simple-amplifier support

[Mark Brown]

On Mon, Jun 25, 2018 at 08:28:32PM +0800, Chen-Yu Tsai wrote:

> I think slightly different semantics apply for "shutdown" vs "mute"
> pins / controls.
> "shutdown" implies a low power, if not powered off altogether, mode which might
> require a slight delay to charge up when the amp is enabled. "mute" is
> just that,
> disconnecting the output, which would be useful in masking pops or other noises,
> but does nothing to help power consumption.

> Not sure if the subtle differences can be handled in DAPM, but it would be nice
> to have. I've seen devices that have both control pins.

It's certainly potentially useful to have pins for both and treat them
differently - ideally something that's a mute would get autodisable type
treatment so we mask out any pops in the input path but also make it
available to userspace if it needs it.  That's something that could be
done when the need arises though, until something that actually has both
controls appears handling a mute pin like a power control is probably
going to result in the most reliable integration.

Having the binding specify both differently would be good for future
proofing.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 488 bytes
Desc: not available
URL: <http://mailman.alsa-project.org/pipermail/alsa-devel/attachments/20180625/8998ca04/attachment-0001.sig>