Re: [PATCH v4] spi: dt-bindings: microchip,pic32mzda-spi: Convert to DT schema

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] The schema incorrectly restricts `cs-gpios` to `maxItems: 1` and makes it strictly required, breaking multi-device and grounded-CS SPI bus configurations.
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--- Patch [1]: [PATCH v4] spi: dt-bindings: microchip,pic32mzda-spi: Convert to DT schema ---
commit fca958be633f7ae75e390f0bb61a2c6c29a85193
Author: Udaya Kiran Challa <[email protected]>

spi: dt-bindings: microchip,pic32mzda-spi: Convert to DT schema

Convert Microchip PIC32 SPI controller devicetree binding from legacy text
format to DT schema.

Link to v3: https://lore.kernel.org/all/[email protected]/
Link to v2: https://lore.kernel.org/all/[email protected]/
Link to v1: https://lore.kernel.org/all/[email protected]/

> diff --git a/Documentation/devicetree/bindings/spi/microchip,pic32mzda-spi.yaml b/Documentation/devicetree/bindings/spi/microchip,pic32mzda-spi.yaml
> new file mode 100644
> index 0000000000000..2ef3480fa63e4
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/spi/microchip,pic32mzda-spi.yaml

[ ... ]

> +  clocks:
> +    maxItems: 1
> +
> +  clock-names:
> +    items:
> +      - const: mck0
> +
> +  cs-gpios:
> +    maxItems: 1

[Severity: Medium]
Does this limit the controller to a single device? The legacy text binding
explicitly allowed multiple pins to be used for chip selects. 

The SPI core in drivers/spi/spi.c supports multiple devices by dynamically
expanding the number of chip selects if multiple GPIOs are provided. Setting
this to a maximum of one breaks valid multiplexed SPI bus configurations.

> +
> +  dmas:
> +    items:
> +      - description: RX DMA channel
> +      - description: TX DMA channel

[ ... ]

> +required:
> +  - compatible
> +  - reg
> +  - interrupts
> +  - interrupt-names
> +  - clocks
> +  - clock-names
> +  - cs-gpios

[Severity: Medium]
Should cs-gpios be strictly required? 

Making it mandatory breaks device tree backward compatibility for valid
hardware configurations where a single SPI device's chip select is permanently
tied to its active state (e.g., tied to ground). In such tied-low
configurations, no software chip select toggling is needed, so the property
is legitimately omitted from the hardware description.

> +
> +unevaluatedProperties: false
> +
> +examples:

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Sashiko AI review · https://sashiko.dev/#/patchset/[email protected]?part=1