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

[Ajith Anandhan <ajithanandhan0406@gmail.com>]

On 10/30/25 10:42 PM, Jonathan Cameron wrote:
> 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;
>> +        };
>> +    };
>> +...
>> +

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.