Re: [PATCH v2 1/3] dt-bindings: iio: adc: add AD762x/AD796x ADCs

[Trevor Gamblin <tgamblin@baylibre.com>]

On 2024-08-10 8:10 a.m., Krzysztof Kozlowski wrote:
> On 09/08/2024 20:41, Trevor Gamblin wrote:
>> Add a binding specification for the Analog Devices Inc. AD7625,
>> AD7626, AD7960, and AD7961 ADCs.
>>
> Thank you for your patch. There is something to discuss/improve.
>
>> +allOf:
>> +  - if:
>> +      required:
>> +        - ref-supply
>> +    then:
>> +      # refin-supply is not needed if ref-supply is given
> Not needed or not allowed? Schema says the latter.
Yes, this is poor wording on my part. I will fix it to say "not allowed".
>
>> +      properties:
>> +        refin-supply: false
>> +  - if:
>> +      required:
>> +        - refin-supply
>> +    then:
>> +      # ref-supply is not needed if refin-supply is given
>> +      properties:
>> +        ref-supply: false
>> +  - if:
>> +      properties:
>> +        compatible:
>> +          contains:
>> +            enum:
>> +              - adi,ad7625
>> +              - adi,ad7626
>> +    then:
>> +      properties:
>> +        en2-gpios: false
>> +        en3-gpios: false
>> +        adi,en2-always-on: false
>> +        adi,en3-always-on: false
>> +
>> +  - if:
>> +      properties:
>> +        compatible:
>> +          contains:
>> +            enum:
>> +              - adi,ad7960
>> +              - adi,ad7961
>> +    then:
>> +      # ad796x parts must have one of the two supplies
>> +      oneOf:
>> +        - required: [ref-supply]
>> +        - required: [refin-supply]
> That's duplicating first and second if. And all three - comment, first
> if:then: and this one here is kind of contradictory so I don't know what
> you want to achieve.

It sounds like there's a better way for me to specify this, but I'm not 
exactly sure how.

The AD762x parts can operate without external references, so the intent 
was that neither REF nor REFIN was required in the bindings, but if one 
is given then the other can't be.

For the AD796x parts, one of REF or REFIN must be provided, but not 
both. If REFIN is provided, then REF doesn't need an input because a 
reference voltage is generated on REF. If REF is provided, then REFIN is 
tied to ground.

Maybe there's a simpler way for me to specify the whole block?

>
>
>> +
>> +additionalProperties: false
>> +
>> +examples:
>> +  - |
>> +    adc {
>> +        compatible = "adi,ad7625";
>> +        vdd1-supply = <&supply_5V>;
>> +        vdd2-supply = <&supply_2_5V>;
>> +        vio-supply = <&supply_2_5V>;
>> +        io-backends = <&axi_adc>;
>> +        clocks = <&ref_clk>;
>> +        pwms = <&axi_pwm_gen 0 0>, <&axi_pwm_gen 1 0>;
>> +        pwm-names = "cnv", "clk_gate";
> Make example complete - en0 or en1 GPIOs or whatever else is applicable.
Will do, thank you.
>
>
> Best regards,
> Krzysztof
>