Re: [RFC PATCH 1/3] dt-bindings: iio: adc: Add TI ADS1120 binding

[Jonathan Cameron <jonathan.cameron@huawei.com>]

On Thu, 30 Oct 2025 22:04:09 +0530
Ajith Anandhan <ajithanandhan0406@gmail.com> wrote:

> Add device tree binding documentation for the Texas Instruments
> ADS1120.
> 
> The binding defines required properties like compatible, reg, and
> SPI configuration parameters.
> 
> Link: https://www.ti.com/lit/gpn/ads1120
Datasheet: https://www.ti.com/lit/gpn/ads1120

Is a somewhat official tag for these. Though better to put it in the dt-binding
doc itself as well or instead of here.

> Signed-off-by: Ajith Anandhan <ajithanandhan0406@gmail.com>
> ---
>  .../bindings/iio/adc/ti,ads1120.yaml          | 50 +++++++++++++++++++
>  1 file changed, 50 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..09285c981
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/adc/ti,ads1120.yaml
> @@ -0,0 +1,50 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/iio/adc/ti,ads1120.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Texas Instruments ADS1120 4-channel, 16-bit, 2kSPS ADC
> +
> +maintainers:
> +  - Ajith Anandhan <ajithanandhan0406@gmail.com>
> +
> +properties:
> +  compatible:
> +    const: ti,ads1120
> +
> +  reg:
> +    maxItems: 1
> +
> +  spi-max-frequency:
> +    maximum: 4000000
> +
> +  spi-cpha: true
> +
> +  "#io-channel-cells":
> +    const: 1

Power supplies should be here and required (even if real boards
rely on stub regulators). 

Looks like there is an optional reference as well - so include that
but not as required (use internal ref if not supplied).

There is a data ready pin as well so I'd expect an interrupt.

All these should be in the binding from the start as we want it
to be as complete as possible.  The driver doesn't have to use everything
the binding supplies.

> +
> +required:
> +  - compatible
> +  - reg
> +
> +allOf:
> +  - $ref: /schemas/spi/spi-peripheral-props.yaml#
> +
> +unevaluatedProperties: false
> +
> +examples:
> +  - |
> +    spi {
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        adc@0 {
> +            compatible = "ti,ads1120";
> +            reg = <0>;
> +            spi-max-frequency = <4000000>;
> +            spi-cpha;
> +        };
> +    };
> +...
> +