Re: [PATCH v6 1/4] dt-bindings: iio: adc: Add ltc2378

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] The binding incorrectly forces `ref-supply` to be mandatory (while forbidding `refin-supply`) for LTC2378 and most other devices, and wrongly forbids `ref-supply` for LTC2338-18. This contradicts the physical hardware capabilities.
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--- Patch [1]: [PATCH v6 1/4] dt-bindings: iio: adc: Add ltc2378 ---
commit 5b94ffdebbdd7e1b8c34a651dee8aae08509770e
Author: Marcelo Schmitt <marcelo.schmitt@analog.com>

dt-bindings: iio: adc: Add ltc2378

This commit adds device tree bindings for the Analog Devices LTC2378
and similar ADCs. It defines the required properties, compatible strings
with fallback enforcement, and constraints for voltage supplies.

> diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ltc2378.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ltc2378.yaml
> new file mode 100644
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/adc/adi,ltc2378.yaml

[ ... ]

> +allOf:
> +  # Except for LTC2338, all designs require a voltage reference input
> +  - if:
> +      properties:
> +        compatible:
> +          not:
> +            contains:
> +              enum:
> +                - adi,ltc2338-18
> +    then:
> +      required:
> +        - ref-supply
> +      properties:
> +        refin-supply: false
> +    else:
> +      properties:
> +        ref-supply: false

[Severity: Medium]
Could these constraints cause a validation regression for valid hardware
configurations?

For example, if the LTC2378 uses an internal reference without an external
supply, forcing ref-supply to be mandatory (while forbidding refin-supply)
might cause valid device trees to fail validation unless a dummy regulator is
instantiated.

Similarly, does the LTC2338-18 support overdriving the internal reference
buffer? If so, forbidding ref-supply for adi,ltc2338-18 could prevent accurate
hardware descriptions when an external reference is applied.

Should these constraints be adjusted to fully reflect the physical hardware
capabilities and internal reference features described in the datasheets?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/cover.1783629101.git.marcelo.schmitt@analog.com?part=1