Re: [PATCH v4 09/11] dt-bindings: input: Document hid-over-spi DT schema

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
- [High] The `read-opcode` and `write-opcode` properties are defined as `uint8`, which will cause the driver to fail probing with `-EOVERFLOW` if using u32 reads.
- [Low] Missing 'reg' property in the 'required' list for an SPI peripheral.
--

commit 455b6048d6e6dd86252693c3c8edc0762c5dbba4
Author: Jingyuan Liang <jingyliang@chromium.org>

dt-bindings: input: Document hid-over-spi DT schema

Documentation describes the required and optional properties for
implementing Device Tree for a Microsoft G6 Touch Digitizer that
supports HID over SPI Protocol 1.0 specification.

> diff --git a/Documentation/devicetree/bindings/input/hid-over-spi.yaml b/Documentation/devicetree/bindings/input/hid-over-spi.yaml
> new file mode 100644
> index 0000000000000..27cf311e0aab0
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/input/hid-over-spi.yaml

[ ... ]

> +  read-opcode:
> +    $ref: /schemas/types.yaml#/definitions/uint8
> +    description:
> +      Value to be used in Read Approval packets. 1 byte.
> +
> +  write-opcode:
> +    $ref: /schemas/types.yaml#/definitions/uint8
> +    description:
> +      Value to be used in Write Approval packets. 1 byte.

[Severity: High]
Will defining these as uint8 cause the driver probe to fail?

In the driver (drivers/hid/spi-hid/spi-hid-of.c), spi_hid_of_populate_config()
reads these using device_property_read_u32().

If a conforming device tree provides 1-byte properties,
device_property_read_u32() will return -EOVERFLOW because the property length
is less than 4 bytes, causing the probe to abort.

Should the driver be updated to use device_property_read_u8(), or should
these schema properties be uint32?

> +
> +required:
> +  - compatible
> +  - interrupts
> +  - reset-gpios
> +  - vdd-supply

[Severity: Low]
Should 'reg' be included in this required list?

Although spi-controller.yaml enforces 'reg' for child nodes matching the
@[0-9a-f]+$ pattern, a malformed node without a unit address would bypass
this check and silently pass schema validation against this binding.

> +  - input-report-header-address
> +  - input-report-body-address
> +  - output-report-address
> +  - read-opcode
> +  - write-opcode

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260609-send-upstream-v4-0-b843d5e6ced3@chromium.org?part=9