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

[Mark Brown]

On Fri, Apr 10, 2026 at 10:03:30AM +0200, Herve Codina wrote:
> Mark Brown <broonie@xxxxxxxxxx> 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.

That does seem larger than any real system would ever need.

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