Re: [PATCH RFC 2/3] dt-bindings: iio: adc: Add excitation current sources properties

[David Lechner]

On 6/18/26 7:33 PM, Kurt Borja wrote:
> Some ADCs incorporate current sources that provide excitation current to
> resistive temperature devices (RTDs), thermistors diodes and other
> resistive sensors that require constant current biasing.
> 
> The maxItems constraint of 16 is arbitrary but should be big enough for
> most devices.

I wouldn't put an arbitrary limit here. The bindings that include it
can extend it to add a limit that makes sense instead.

> 
> Signed-off-by: Kurt Borja <kuurtb@xxxxxxxxx>
> ---
>  Documentation/devicetree/bindings/iio/adc/adc.yaml | 23 ++++++++++++++++++++++
>  1 file changed, 23 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/iio/adc/adc.yaml b/Documentation/devicetree/bindings/iio/adc/adc.yaml
> index c74c2084fdb68c..106b1e317411d5 100644
> --- a/Documentation/devicetree/bindings/iio/adc/adc.yaml
> +++ b/Documentation/devicetree/bindings/iio/adc/adc.yaml
> @@ -83,6 +83,29 @@ properties:
>        This array describes either a single reference source or a positive and
>        negative reference sources.
>  
> +  excitation-channels:
> +    $ref: /schemas/types.yaml#/definitions/uint32-array
> +    maxItems: 16
> +    minItems: 1
> +    description:
> +      Excitation current sources provide current to resistive temperature
> +      devices (RTDs), thermistors diodes and other resistive sensors that
> +      require constant current biasing.
> +
> +      This array describes the mux configuration of the excitation current
> +      sources.
> +
> +  excitation-current-microamp:
> +    maxItems: 16
> +    minItems: 1
> +    description:
> +      Excitation current sources provide current to resistive temperature
> +      devices (RTDs), thermistors diodes and other resistive sensors that
> +      require constant current biasing.
> +
> +      This array describes the current configuration of the excitation current
> +      sources or the single matched current for all sources.
> +
>  anyOf:
>    - oneOf:
>        - required:
>