Re: [PATCH v2 1/2] dt-bindings: iio: adc: Add TI ADS1120 binding

[Jonathan Cameron]

On Sun,  9 Nov 2025 19:41:18 +0530
Ajith Anandhan <ajithanandhan0406@xxxxxxxxx> wrote:

> Add device tree binding documentation for the Texas Instruments
> ADS1120.
> 
> The binding defines required properties like compatible, reg, and
> SPI configuration parameters.
> 
> Signed-off-by: Ajith Anandhan <ajithanandhan0406@xxxxxxxxx>
> ---
>  .../bindings/iio/adc/ti,ads1120.yaml          | 109 ++++++++++++++++++
>  1 file changed, 109 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iio/adc/ti,ads1120.yaml
> 
> diff --git a/Documentation/devicetree/bindings/iio/adc/ti,ads1120.yaml b/Documentation/devicetree/bindings/iio/adc/ti,ads1120.yaml
> new file mode 100644
> index 000000000..2449094af
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/adc/ti,ads1120.yaml
>
> +
> +  vref-supply:
> +    description: |
> +      Optional external voltage reference. Can be connected to either
> +      REFP0/REFN0 or REFP1/REFN1 pins. If not supplied, the internal
> +      2.048V reference is used.

How do you know which set of inputs is used?  Looks like a register
needs to be programmed to pick between them.

> +
> +  ti,avdd-is-ref:
> +    type: boolean
> +    description: |
> +      If present, indicates that the AVDD supply voltage is of sufficient
> +      quality and stability to be used as the voltage reference instead of
> +      the internal reference. This allows the driver to select AVDD as the
> +      reference source for potentially better performance.

This one is interesting as I don't recall anyone arguing this made
sense before.  In what way better performance?  Are their boards out
there where this definitely makes sense to do?