Re: [PATCH v6 02/11] dt-bindings: pwm: rzg2l-gpt: Document renesas,poegs property

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] The `renesas,poegs` property improperly encodes the consumer's channel index as a phandle specifier, which is a Devicetree anti-pattern and breaks standard phandle-array parsing semantics.
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commit 9d7f9847d3f320fb715022b6159c9c7e869aeedd
Author: Biju Das <biju.das.jz@bp.renesas.com>

dt-bindings: pwm: rzg2l-gpt: Document renesas,poegs property

RZ/G2L GPT IP supports output pin disable function by dead time
error and detecting short-circuits between output pins.
Add documentation for the optional property renesas,poegs to
link a pair of GPT IOs with POEG.

> diff --git a/Documentation/devicetree/bindings/pwm/renesas,rzg2l-gpt.yaml b/Documentation/devicetree/bindings/pwm/renesas,rzg2l-gpt.yaml
> --- a/Documentation/devicetree/bindings/pwm/renesas,rzg2l-gpt.yaml
> +++ b/Documentation/devicetree/bindings/pwm/renesas,rzg2l-gpt.yaml

[ ... ]

> @@ -245,6 +245,28 @@ properties:
>    resets:
>      maxItems: 1
>  
> +  renesas,poegs:
> +    minItems: 1
> +    maxItems: 8
> +    $ref: /schemas/types.yaml#/definitions/phandle-array
> +    items:
> +      items:
> +        - description: phandle to POEG instance that serves the output disable
> +        - enum: [ 0, 1, 2, 3, 4, 5, 6, 7 ]
> +          description: |
> +            An index identifying pair of GPT channels.

[Severity: Medium]
Does this property correctly follow standard Devicetree phandle semantics?

By Devicetree specification, phandle arguments in a phandle-array are
defined and interpreted by the target provider node, with their length
dictated by a cell-count property on the provider.

This definition appears to invert that model by using the specifier to encode
the consumer's (GPT) own channel index rather than a provider argument.

Additionally, standard OS-agnostic DT parsers might fail to resolve this
because the referenced provider binding (renesas,rzg2l-poeg.yaml) enforces
additionalProperties: false and natively lacks a #poeg-cells property to
dictate the specifier length.

Is it possible to redesign this binding so it doesn't encode the consumer's
index into the provider's phandle argument, or at least ensure the POEG
provider specifies a #poeg-cells property?

> +              <0> : GPT channels 0 and 1
> +              <1> : GPT channels 2 and 3
> +              <2> : GPT channels 4 and 5
> +              <3> : GPT channels 6 and 7

[ ... ]

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260604095647.108654-1-biju.das.jz@bp.renesas.com?part=2