Re: [PATCH v3 09/14] iio: adc: ad7768: Add VCM regulator support

[Jonathan Cameron]

On Thu, 13 Aug 2026 15:57:02 +0200
Janani Sunil <janani.sunil@xxxxxxxxxx> wrote:

> Expose the on-chip common mode voltage output through the regulator
> framework. Support the three fixed output levels and the
> supply-dependent AVDD1/2 setting.
> 
> Keep the ADC runtime active while VCM is enabled and release the runtime
> PM reference when the output is disabled.

Why?  Expectation I think is that VCM is used for powering analog
front ends or simple circuity directly tied up to what we are measuring
with the ADC.  Feels like it may well want to only be powered up when
about to sample stuff.

Perhaps that is a problem for a front end device we aren't currently
describing.  We don't really have a way to do those for backend 
/ dma grabbed data today as there isn't a consumer interface in the
same way there is for the software managed buffers path.

> 
> Signed-off-by: Janani Sunil <janani.sunil@xxxxxxxxxx>