Re: [PATCH 2/3] dt-bindings: iio: dac: add support for MCP48FEB02 SPI

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
- [Medium] The schema retains `additionalProperties: false` at the root level while introducing a conditional `$ref` to `spi-peripheral-props.yaml` in the `allOf` block. This breaks schema validation for standard SPI properties.
- [Low] The newly added SPI device tree example uses an inappropriate SPI chip select value (`0x60`), copied from the I2C device address example.
--

--- Patch [2]: [PATCH 2/3] dt-bindings: iio: dac: add support for MCP48FEB02 SPI ---
commit a357ffde05c7807cd64bca71103d780d8dde416b
Author: Ariana Lazar <ariana.lazar@microchip.com>

dt-bindings: iio: dac: add support for MCP48FEB02 SPI

This commit adds SPI support for the MCP48FxBy1/2/4/8 DAC families to the
existing MCP47FEB02 device tree binding. It introduces the new compatible
strings, the spi-max-frequency property, and a devicetree example for SPI.

> diff --git a/Documentation/devicetree/bindings/iio/dac/microchip,mcp47feb02.yaml b/Documentation/devicetree/bindings/iio/dac/microchip,mcp47feb02.yaml
> index d131f136bd151..d25c763241a4f 100644
> --- a/Documentation/devicetree/bindings/iio/dac/microchip,mcp47feb02.yaml
> +++ b/Documentation/devicetree/bindings/iio/dac/microchip,mcp47feb02.yaml
> @@ -178,6 +239,13 @@ required:
>    - vdd-supply
>  
>  allOf:
> +  - if:
> +      properties:
> +        compatible:
> +          contains:
> +            pattern: "^microchip,mcp48f[ev]b[0-2][1248]$"
> +    then:
> +      $ref: /schemas/spi/spi-peripheral-props.yaml#

[ ... ]

> +    then:
> +      properties:
> +        spi-max-frequency: false
> +
>  additionalProperties: false

[Severity: Medium]
Since this schema now includes a conditional $ref to spi-peripheral-props.yaml
in the allOf block, should this be changed to unevaluatedProperties: false?

JSON Schema limits additionalProperties: false to only evaluating properties
explicitly declared in the root properties or patternProperties. Any standard
SPI properties pulled in via the conditional $ref will be incorrectly rejected
by dt_binding_check.

>  examples:
> @@ -299,4 +424,29 @@ examples:
>              };
>          };
>      };
> +  - |
> +    spi {
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        dac@60 {
> +          compatible = "microchip,mcp48feb02";
> +          reg = <0x60>;

[Severity: Low]
Is 0x60 intended to be used as an SPI chip select here, or was this copied
from the I2C example?

Typically, an SPI chip select would be 0 or 1, and the node would be named
dac@0 with reg = <0>.

> +          vdd-supply = <&vdac_vdd>;
> +          vref-supply = <&vref_reg>;
> +          spi-max-frequency = <10000000>;
> +
> +          #address-cells = <1>;
> +          #size-cells = <0>;
> +          channel@0 {
> +            reg = <0>;
> +            label = "Adjustable_voltage_ch0";
> +          };
> +
> +          channel@1 {
> +            reg = <0x1>;
> +            label = "Adjustable_voltage_ch1";
> +          };
> +        };
> +    };
>  ...

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260723-mcp47feb02_refactor-v1-0-ee59e63672bc@microchip.com?part=2