Re: [PATCH v3 4/5] dt-bindings: iio: adc: ad7192: Add AD7194 support

[Alisa-Dariana Roman]

On 08.02.2024 20:03, Conor Dooley wrote:
> Hey,
>
> On Thu, Feb 08, 2024 at 07:24:58PM +0200, Alisa-Dariana Roman wrote:
>
> > +patternProperties:
> > +  "^channel@([0-7a-f])$":
> > +    type: object
> > +    $ref: adc.yaml
> > +    unevaluatedProperties: false
> > +
> > +    properties:
> > +      reg:
> > +        description: The channel index.
> > +        minimum: 0
> > +        maximum: 7
>
> There are only 8 possible channels, at indices 0 to 7, so why is the
> pattern property more permissive than that? Shouldn't "^channel@[0-7]$"
> suffice?
>
> > +
> > +       diff-channels:
>
> > +        description: |
> > +          The differential channel pair for Ad7194 configurable channels. The
> > +          first channel is the positive input, the second channel is the
> > +          negative input.
>
> This duplicates the description in adc.yaml
>
> > +        items:
> > +          minimum: 1
> > +          maximum: 16
>
> Hmm, this makes me wonder: why doesn't this match the number of channels
> available and why is 0 not a valid channel for differential measurements?
>
> Thanks,
> Conor.

Hello and thank you for the feedback!

I will change the pattern property and the description.

Regarding the channels, I followed the existing style of the driver for 
the AD7194 channels: one iio channel for each pseudo-differential input 
channel(AINx - AINCOM), summing up to 16 channels; and one iio channel 
for each differential channel (AINx - AINy), summing up to 8 channels. 
For the diff-channels, I thought the possible values should be 1->16 
corresponding to AIN1->AIN16 (I will add this to the description as 
suggested by David).

Kind regards,
Alisa-Dariana Roman