Re: [PATCH v13 1/3] dt-bindings: adc: add AD7173

Jonathan Cameron
2024-02-24T17:07:25Z

On Wed, 21 Feb 2024 10:29:30 +0200
Ceclan Dumitru <mitrutzceclan@gmail.com> wrote:

> On 2/20/24 22:54, David Lechner wrote:
> > On Tue, Feb 20, 2024 at 3:43 AM Dumitru Ceclan <mitrutzceclan@gmail.com> wrote:
>
> ...
>
> >> + clocks:
> >> + maxItems: 1
> >> + description: |
> >
> > Don't need `|` here.
> >
> The description contains ": ". Without '|' yaml syntax considers the
> whole string before ':' as another attribute
>
> >> + Optional external clock source. Can include one clock source: external
> >> + clock or external crystal.
> >> +
>
> ...
>
> >> +
> >> + diff-channels:
> >> + items:
> >> + minimum: 0
> >> + maximum: 31
> >> +
> >
> > Are we missing `bipolar: true` here? (since we have
> > unevaluatedProperties: false)
> >
>
> No, since we are referencing the adc schema "$ref: adc.yaml"
> Which contains:
> """
> bipolar:
>
> $ref: /schemas/types.yaml#/definitions/flag
>
> description: If provided, the channel is to be used in bipolar mode.
> """
>
>
> ...
>
> >> +
> >> +required:
> >> + - compatible
> >> + - reg
> >
> > Aren't the various power supplies supposed to be required?
> >
> > - avdd-supply
> > - avdd2-supply
> > - iovdd-supply
>
> From my point of view, if someone uses a single supply (avdd == avdd2 ==
> iovdd), and uses only the internal reference then the supplies should
> not necessarily be required.

Convention is that anything that represent a voltage on a pin that
is needed for operation should be required. Key here is the difference
from optional supplies where the driver does something different.
vref is a good example of this. The ones above are always needed I
think.

Obviously they may all say the same thing if they are connected
externally.