Re: [PATCH v4 1/2] dt-bindings: serial: Document WK2xxx SPI UART

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] The binding schema and example contradict the commit message regarding RS-485 and flow-control support for the WK2132 and WK2202 variants.
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commit 812f6612c7639102da515af64bd9d5022ac17f75
Author: Zi Jie Zhao <zjzhao@edatec.cn>

dt-bindings: serial: Document WK2xxx SPI UART

This commit adds a device tree binding schema for the WK2xxx family of SPI
to UART bridge ICs. It specifies required properties for each channel and
aims to differentiate compatible strings by channel count and register
availability, specifically noting missing RS-485 and flow-control registers
for WK2132 and WK2202.

> diff --git a/Documentation/devicetree/bindings/serial/wkmic,wk2124.yaml b/Documentation/devicetree/bindings/serial/wkmic,wk2124.yaml
> new file mode 100644
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/serial/wkmic,wk2124.yaml
[ ... ]
> +allOf:
> +  - $ref: /schemas/spi/spi-peripheral-props.yaml#
> +
> +  - if:
> +      properties:
> +        compatible:
> +          contains:
> +            enum:
> +              - wkmic,wk2132
> +              - wkmic,wk2202
> +    then:
> +      patternProperties:
> +        "^serial@[23]$": false

[Severity: Medium]
The commit message states that the binding accounts for missing hardware
flow-control and RS-485 registers on the WK2132 and WK2202 variants. However,
this conditional block only restricts the channel count by rejecting the
higher serial nodes. Should this block also explicitly restrict the RS-485
and hardware flow-control properties to prevent invalid configurations from
passing schema validation?

[ ... ]
> +examples:
> +  - |
[ ... ]
> +        serial@0 {
> +            compatible = "wkmic,wk2132";
> +            reg = <0>;
> +            spi-max-frequency = <10000000>;
> +            clocks = <&xtal>;
> +            interrupt-parent = <&gpio>;
> +            interrupts = <24 IRQ_TYPE_LEVEL_LOW>;
> +            #address-cells = <1>;
> +            #size-cells = <0>;
> +
> +            serial@0 {
> +                reg = <0>;
> +            };
> +
> +            serial@1 {
> +                reg = <1>;
> +                rs485-rts-active-low;
> +                linux,rs485-enabled-at-boot-time;
> +            };
> +        };
> +    };

[Severity: Medium]
Does this example incorrectly demonstrate RS-485 capabilities on the WK2132
variant? The commit message indicates that WK2132 is missing the hardware
RS-485 registers, but this example actively applies RS-485 properties to its
serial child node.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260908103129.58085-1-zjzhao@edatec.cn?part=1