Re: [PATCH v4 1/2] dt-bindings: iio: adc: Add MAX1241 device tree bindings in documentation

[Jonathan Cameron <jic23@kernel.org>]

On Sun, 22 Mar 2020 11:53:17 +0200
Alexandru Lazar <alazar@startmail.com> wrote:

> > Yep.
> > Jonathan refers to Vdd input/pin [on the chip] which is different from Vref [REF
> > pin].
> > Not all drivers define Vdd.
> > Some call it AVdd.
> > 
> > [...]
> > 
> > It's an idea to add it, and that can give control to the driver to power-up the
> > ADC, by defining a regulator [vdd-supply] in the device-tree.  
> 
> Hmm... I don't know how useful this would be for the 124x family (I
> doubt anyone who needs one of these will power it from its own,
> independent supply), 

You'd be surprised how often this gets added to drivers precisely because
people will put it on a controllable supply.  It may well not have it's own
supply but it may share one with a bunch of other external chips and
all of them need to use the regulator framework controls to make sure it's
only disabled when they are all suspended etc.

See the number of times Linus Walleij has added this for various sensors
and ADCs because he has boards where the control is needed.

Jonathan


> but it's a pretty harmless change. I can't think of
> any reason to say no :-).
> 
> Thanks,
> Alex