Re: [PATCH 1/2] dt-bindings: mmc: renesas,sdhi: Add mux-states property

[Conor Dooley]

On Fri, Nov 28, 2025 at 05:15:38PM +0100, Josua Mayer wrote:
> Add mux controller support for when sdio lines are muxed between a host
> and multiple cards.
> 
> There are several devices supporting a choice of eMMC or SD on a single
> board by both dip switch and gpio, e.g. Renesas RZ/G2L SMARC SoM and
> SolidRun RZ/G2L SoM.
> 
> In-tree dts for the Renesas boards currently rely on preprocessor macros
> to hog gpios and define the card.
> 
> By adding mux-states property to sdio controller description, boards can
> correctly describe the mux that already exists in hardware - and drivers
> can coordinate between mux selection and probing for cards.
> 
> Signed-off-by: Josua Mayer <josua@xxxxxxxxxxxxx>
> ---
>  Documentation/devicetree/bindings/mmc/renesas,sdhi.yaml | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/mmc/renesas,sdhi.yaml b/Documentation/devicetree/bindings/mmc/renesas,sdhi.yaml
> index c754ea71f51f7..55635c60ad73a 100644
> --- a/Documentation/devicetree/bindings/mmc/renesas,sdhi.yaml
> +++ b/Documentation/devicetree/bindings/mmc/renesas,sdhi.yaml
> @@ -106,6 +106,11 @@ properties:
>    iommus:
>      maxItems: 1
>  
> +  mux-states:
> +    description:
> +      mux controller node to route the SDIO signals from SoC to cards.
> +    maxItems: 1
> +
>    power-domains:
>      maxItems: 1
>  
> @@ -262,9 +267,17 @@ unevaluatedProperties: false
>  examples:
>    - |
>      #include <dt-bindings/clock/r8a7790-cpg-mssr.h>
> +    #include <dt-bindings/gpio/gpio.h>
>      #include <dt-bindings/interrupt-controller/arm-gic.h>
> +    #include <dt-bindings/pinctrl/rzg2l-pinctrl.h>
>      #include <dt-bindings/power/r8a7790-sysc.h>
>  
> +    mux: mux-controller {
> +            compatible = "gpio-mux";
> +            #mux-state-cells = <1>;
> +            mux-gpios = <&pinctrl RZG2L_GPIO(22, 1) GPIO_ACTIVE_LOW>;
> +    };

This node should be removed, the tooling will provide a fake phandle to
satisfy your mux-states property.

pw-bot: changes-requested

> +
>      sdhi0: mmc@ee100000 {
>          compatible = "renesas,sdhi-r8a7790", "renesas,rcar-gen2-sdhi";
>          reg = <0xee100000 0x328>;
> @@ -275,6 +288,7 @@ examples:
>          max-frequency = <195000000>;
>          power-domains = <&sysc R8A7790_PD_ALWAYS_ON>;
>          resets = <&cpg 314>;
> +        mux-states = <&mux 0>;
>      };
>  
>      sdhi1: mmc@ee120000 {
> 
> -- 
> 2.51.0
>

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