Re: [PATCH v1 10/15] iio: adc: ad7768-1: Add support for variable VCM

From: Jonathan Cameron
Date: Sun Jan 12 2025 - 07:46:13 EST


On Sat, 11 Jan 2025 23:37:29 -0300
Jonathan Santos <jonath4nns@xxxxxxxxx> wrote:

> On 01/07, David Lechner wrote:
> > On 1/7/25 9:26 AM, Jonathan Santos wrote:
> > > From: Sergiu Cuciurean <sergiu.cuciurean@xxxxxxxxxx>
> > >
> > > The VCM output voltage can be used as a common-mode voltage within the
> > > amplifier preconditioning circuits external to the AD7768-1.
> > >
> > > This change exports the VCM as an iio attribute and makes it available
> > > for configuration.
> >
> > We model common mode voltage inputs as a regulator consumer (e.g. vcm-supply in
> > DT), so should we make this a regulator provider instead?
> >
> > It could be used with "regulator-output" to be able to control it from sysfs
> > or if the amplifier ends up in the devicetree for other reasons, the amplifier
> > driver could control the regulator instead of requiring it to by done in sysfs.
> >
>
> Ok, that is an interesting approach, I will try this. It makes sense to
> have it in the devicetree.

I'd be a bit surprised if this ended up being varied in real systems.
So maybe start with a solution that has DT provide a value suitable to the
amplifier (ideally because the amplifier requests it) and we can figure
more dynamic stuff out later if needed.

Jonathan