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

[Ajith Anandhan]

On 10/30/25 10:42 PM, Jonathan Cameron wrote:
> On Thu, 30 Oct 2025 22:04:09 +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.
> >
> > 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@xxxxxxxxx>
> > ---
> >   .../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@xxxxxxxxx>
> > +
> > +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;
> > +        };
> > +    };
> > +...
> > +

Hi Jonathan,

Thank you for the detailed review and helpful suggestions.

I'll update the binding to include the following:
- Add required power supply property (avdd-supply) and optional vref-supply.
- Add interrupt and interrupt-names for DRDY and DOUT.
- Move the datasheet link into the dt-binding description.

I'll incorporate these changes and resend as a V2 (non-RFC) patch series.

--
BR,
Ajith Anandhan.