Re: [PATCH RFC v2 1/3] dt-bindings: iio: adc: Add reference-source property

[David Lechner]

On 7/2/26 2:20 PM, Jonathan Cameron wrote:
> On Mon, 22 Jun 2026 14:40:10 -0500
> David Lechner <dlechner@xxxxxxxxxxxx> wrote:
> 
>> On 6/22/26 2:30 PM, Kurt Borja wrote:
>>> Some ADCs have configurable voltage reference sources for each channel.
>>>
>>> Signed-off-by: Kurt Borja <kuurtb@xxxxxxxxx>
>>> ---
>>>  Documentation/devicetree/bindings/iio/adc/adc.yaml | 13 +++++++++++++
>>>  1 file changed, 13 insertions(+)
>>>
>>> diff --git a/Documentation/devicetree/bindings/iio/adc/adc.yaml b/Documentation/devicetree/bindings/iio/adc/adc.yaml
>>> index b9bc02b5b07a4c7..fdad6b8276c934c 100644
>>> --- a/Documentation/devicetree/bindings/iio/adc/adc.yaml
>>> +++ b/Documentation/devicetree/bindings/iio/adc/adc.yaml
>>> @@ -73,6 +73,19 @@ properties:
>>>        device design and can interact with other characteristics such as
>>>        settling time.
>>>  
>>> +  reference-source:  
>>
>> Since this is an array, the name should be `reference-sources`.
>>
>>> +    $ref: /schemas/types.yaml#/definitions/string-array
>>> +    maxItems: 2
>>> +    minItems: 1  
>>
>> Maybe minItems here is OK, but I don't think we should put maxItems here.
>> This way, it stays more flexible for other use cases.
> 
> I'm curious. What other usecases did you have in mind?

I didn't have something specific in mind, but in Kurt's ADS1263 series, we
actually have a case with 3 values for this property already, ADC1 positive,
ADC1 negative and ADC2.

> 
>>
>>> +    description:
>>> +      Indicates the voltage reference source or sources for this channel. Some
>>> +      ADCs usually allow choosing between internal reference sources or a pair
>>> +      of external pins.
>>> +
>>> +      If a single value is provided, it represents a single voltage reference
>>> +      source. If two values are provided, the first one corresponds to the
>>> +      positive source and the second to the negative source.
>>> +
>>>  anyOf:
>>>    - oneOf:
>>>        - required:
>>>   
>>
>