Re: [PATCH 2/6] dt-bindings: iio: dac: ad5791: Add required voltage supplies

[Krzysztof Kozlowski]

On Mon, Oct 28, 2024 at 08:11:14AM +0100, ahaslam@xxxxxxxxxxxx wrote:
> From: Axel Haslam <ahaslam@xxxxxxxxxxxx>
> 
> Vcc, iovcc, vrefp, and vrefn are needed for the DAC to work.
> Add them as required bindings for ad5791.
> 
> Signed-off-by: Axel Haslam <ahaslam@xxxxxxxxxxxx>
> ---
>  .../bindings/iio/dac/adi,ad5791.yaml          | 24 +++++++++++++++++++
>  1 file changed, 24 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/iio/dac/adi,ad5791.yaml b/Documentation/devicetree/bindings/iio/dac/adi,ad5791.yaml
> index fe664378c966..79cb4b78a88a 100644
> --- a/Documentation/devicetree/bindings/iio/dac/adi,ad5791.yaml
> +++ b/Documentation/devicetree/bindings/iio/dac/adi,ad5791.yaml
> @@ -26,6 +26,22 @@ properties:
>    vdd-supply: true
>    vss-supply: true
>  
> +  vcc-supply:
> +    description:
> +      Supply that powers the chip.
> +
> +  iovcc-supply:
> +    description:
> +      Supply for the digital interface.
> +
> +  vrefp-supply:
> +    description:
> +      Positive referance input voltage range. From 5v to (vdd - 2.5)
> +
> +  vrefn-supply:
> +    description:
> +      Negative referance input voltage range. From (vss + 2.5) to 0.
> +
>    adi,rbuf-gain2-en:
>      description: Specify to allow an external amplifier to be connected in a
>        gain of two configuration.
> @@ -47,6 +63,10 @@ required:
>    - reg
>    - vdd-supply
>    - vss-supply
> +  - vcc-supply
> +  - iovcc-supply
> +  - vrefp-supply
> +  - vrefn-supply

So you have six required supplies?

Datasheet says "A voltage range of 2.7 V to 5.5 V *can* be connected",
so doesn't it mean this is optional? Although similar wording is for
other supplies, so maybe it's just imprecise language?

Best regards,
Krzysztof