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

[Jonathan Cameron <jic23@kernel.org>]

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.