Re: [PATCH v5 15/22] arm64: dts: renesas: r9a09g057: Add USB2.0 VBUS_SEL mux-controller support

[Geert Uytterhoeven]

Hi Tommaso,

On Thu, 27 Nov 2025 at 12:51, Tommaso Merciai
<tommaso.merciai.xr@xxxxxxxxxxxxxx> wrote:
> Enable control of USB2.0 VBUSEN via the VBUS_SEL bit in the VBENCTL
> register. According to the RZ/V2H(P) SoC hardware manual, OTG channels
> require VBUS_SEL set, while HOST-only channels require it cleared.
>
> Add `#mux-state-cell` to the usb20phyrst and usb21phyrst reset
> nodes to expose them as mux controllers.
>
> Set the required mux-states in usb2_phy0 (OTG: state 1) and usb2_phy1
> (HOST: state 0) nodes.
>
> This enables proper VBUSEN management for OTG and HOST-only USB2.0
> channels.
>
> Signed-off-by: Tommaso Merciai <tommaso.merciai.xr@xxxxxxxxxxxxxx>

Thanks for your patch!

> --- a/arch/arm64/boot/dts/renesas/r9a09g057.dtsi
> +++ b/arch/arm64/boot/dts/renesas/r9a09g057.dtsi
> @@ -1034,6 +1034,7 @@ usb2_phy0: usb-phy@15800200 {
>                         resets = <&usb20phyrst>;
>                         #phy-cells = <1>;
>                         power-domains = <&cpg>;
> +                       mux-states = <&usb20phyrst 1>;

I am no USB expert, and didn't really follow the USB specifics of
this series, but isn't the selection of host (VBUSEN = 1) or function
(VBUSEN = 0) mode decided at runtime?

>                         status = "disabled";
>                 };
>
> @@ -1047,6 +1048,7 @@ usb2_phy1: usb-phy@15810200 {
>                         resets = <&usb21phyrst>;
>                         #phy-cells = <1>;
>                         power-domains = <&cpg>;
> +                       mux-states = <&usb21phyrst 0>;

The second controller is always used in host mode, so 0 is correct.

>                         status = "disabled";
>                 };
>

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds