Re: [PATCH v5 3/8] dt-bindings: i2c: add support for tsd,mule

Rob Herring
2024-07-08T23:03:33Z

On Mon, Jul 08, 2024 at 06:12:14PM +0200, Farouk Bouabid wrote:
> Theobroma Systems Mule is an MCU that emulates a set of I2C devices,
> among which is an amc6821 and other devices that are reachable through
> an I2C-mux. The devices on the mux can be selected by writing the
> appropriate device number to an I2C config register (amc6821: reg 0xff)
>
> Signed-off-by: Farouk Bouabid <farouk.bouabid@cherry.de>
> ---
> .../devicetree/bindings/i2c/tsd,mule.yaml | 63 ++++++++++++++++++++++
> 1 file changed, 63 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/i2c/tsd,mule.yaml b/Documentation/devicetree/bindings/i2c/tsd,mule.yaml
> new file mode 100644
> index 000000000000..dbbabba8dd6f
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/i2c/tsd,mule.yaml
> @@ -0,0 +1,63 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/i2c/tsd,mule.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Theobroma Systems Mule I2C device
> +
> +maintainers:
> + - Farouk Bouabid <farouk.bouabid@cherry.de>
> + - Quentin Schulz <quentin.schulz@cherry.de>
> +
> +description: |
> + Theobroma Systems Mule is an MCU that emulates a set of I2C devices, among
> + which is an amc6821 and other devices that are reachable through an I2C-mux.
> + The devices on the mux can be selected by writing the appropriate device
> + number to an I2C config register (amc6821: reg 0xff)
> +
> +additionalProperties: true

Must be false.

> +
> +properties:
> + compatible:
> + contains:

No, must define the entries and the order.

> + enum:
> + - tsd,mule
> + - ti,amc6821

Need to drop this from trivial-devices.yaml. We don't define the same
compatible in 2 places.

As the original device was ti,amc6821 and this is a superset, the
binding should first document ti,amc6821 meaning that should be the
filename, title, etc. And then describe the Mule additions. (I mean how
the binding should read, not patch structure. 1 patch for this is fine.)

> +
> + reg:
> + maxItems: 1

To fix the additionalProperties failure you will see, you need to add:

i2c-mux:
type: object

> +
> +required:
> + - compatible
> + - reg
> +
> +examples:
> + - |
> + i2c {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + fan@18 {
> + compatible = "tsd,mule", "ti,amc6821";
> + reg = <0x18>;
> +
> + i2c-mux {
> + compatible = "tsd,mule-i2c-mux";
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + i2c@0 {
> + reg = <0x0>;
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + rtc@6f {
> + compatible = "isil,isl1208";
> + reg = <0x6f>;
> + };
> + };
> + };
> + };
> + };
> +...
>
> --
> 2.34.1
>