Re: [PATCH 2/4] ASoC: dt-bindings: Add support for the GPIOs driven amplifier

[Herve Codina <herve.codina@bootlin.com>]

Hi Mark, Rob,

On Thu, 9 Apr 2026 16:26:25 +0100
Mark Brown <broonie@kernel.org> wrote:

> > > I didn't want to set a particular limit related to the number of GPIOs
> > > used for thje gain value. Of course 2^32 is obviously a lot.  
> 
> > > What do you think about 16 for maxItems?  
> 
> > What is the most you are aware of? Take that and double it.  
> 
> > Seems to me 256 levels would be way more than a human ear could distinguish.  
> 
> There's plenty of gain controls with way more than 256 bits of
> resolution, though I'm not aware of any that are configured via GPIO.
> The step size and absolute values you want can vary dramatically
> depending on application, possibly in the same system (eg, a DAC that
> can be connected to both headphones or speakers) so you often end up
> making practical adjustments in a small subset of the available range
> but that subset can vary a lot for the same part.

Mark, do you think that max 16 GPIOs could be an acceptable limit?

IMHO, this value is large enough to be used as the limit.

> 
> > I guess my point was that really we could deprecate simple-amplifier
> > binding because this one can handle it and more. But I'm not
> > suggesting we do that yet.  
> 
> That's my thinking.

Fine for me to, at the end, deprecate the simple-amplifier.