Re: [PATCH v4 08/13] dt-bindings: iio: adc: adi,ad4134: Document SPI connection mode

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] dt-bindings: invalid and incomplete constraints for spi-rx-bus-width
--

commit a58d6d0037332b8cd9f5b3717ec4b6ddd8e36734
Author: Marcelo Schmitt <marcelo.schmitt@analog.com>

dt-bindings: iio: adc: adi,ad4134: Document SPI connection mode

This commit updates the AD4134 device tree bindings to document different SPI 
connection modes. It introduces the adi,spi-mode and #daisy-chained-devices 
properties along with corresponding constraints for different wiring 
configurations.

> diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad4134.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ad4134.yaml
> index ea6d7e0264190..970e7adb2405b 100644
> --- a/Documentation/devicetree/bindings/iio/adc/adi,ad4134.yaml
> +++ b/Documentation/devicetree/bindings/iio/adc/adi,ad4134.yaml
[ ... ]
> @@ -141,13 +161,36 @@ required:
>    - clocks
>    - clock-names
>  
> -oneOf:
> -  - required:
> -      - ldoin-supply
> -  - required:
> -      - avdd1v8-supply
> -      - dvdd1v8-supply
> -      - clkvdd-supply
> +allOf:
> +  - oneOf:
> +      - required:
> +          - ldoin-supply
> +      - required:
> +          - avdd1v8-supply
> +          - dvdd1v8-supply
> +          - clkvdd-supply
> +
> +  - oneOf:
> +      - required: ['adi,spi-mode', '#daisy-chained-devices']

[Severity: Low]
Neither chain configuration includes spi-rx-bus-width in the required list.

Since JSON Schema property constraints only evaluate when the property is 
present, omitting spi-rx-bus-width from a chain node bypasses the hardware 
constraint. 

Should spi-rx-bus-width be added to the required lists so the SPI controller 
doesn't silently initialize with a single receive lane?

> +        properties:
> +          adi,spi-mode:
> +            const: one-channel-chain
> +          spi-rx-bus-width:
> +            const: 1

[Severity: Low]
Because the core SPI bindings define spi-rx-bus-width as a uint32-array, 
evaluating a device tree value (such as <1>, parsed internally as the JSON 
array [1]) against a scalar causes a strict type mismatch. 

Could this falsely reject valid configurations during dt_binding_check?

> +      - required: ['adi,spi-mode', '#daisy-chained-devices']
> +        properties:
> +          adi,spi-mode:
> +            const: two-channel-chain
> +          spi-rx-bus-width:
> +            items:
> +              - const: 1
> +              - const: 1

[Severity: Low]
This array items constraint validates the first two lanes, but it lacks bounds 
checks. 

Does this need minItems: 2 and maxItems: 2 to properly restrict the overall 
length of the array?

> +      - properties:
> +          '#daisy-chained-devices': false
> +          adi,spi-mode:
> +            enum:
> +              - no-cs
> +              - 4-wire

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/cover.1791309733.git.marcelo.schmitt@analog.com?part=8