[PATCH 1/2] riscv: dts: sophgo: Enable ethernet for Milk-V Duo 256M

[PATCH 1/2] riscv: dts: sophgo: Enable ethernet for Milk-V Duo 256M

[Chen-Yu Yeh]

The SG2002 has an internal ethernet PHY, but on the Milk-V Duo 256M the
ethernet signals are only routed to the RJ45 connector of the optional
IO board.

Enable the GMAC and the MDIO multiplexer so that the interface is usable
when such a board is attached.

Tested on actual Milk-V Duo 256M hardware: the GMAC probes, the MDIO
multiplexer selects the internal bus and the internal EPHY is detected
at address 1:

  eth0: PHY [mdio_mux-0.0:01] driver [Generic PHY]

Link-up was not verified for lack of the IO board.

Signed-off-by: Chen-Yu Yeh <chenyou910331@gmail.com>
---
 arch/riscv/boot/dts/sophgo/sg2002-milkv-duo256m.dts | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/arch/riscv/boot/dts/sophgo/sg2002-milkv-duo256m.dts b/arch/riscv/boot/dts/sophgo/sg2002-milkv-duo256m.dts
index a2797c0bd767..1462a96a1c12 100644
--- a/arch/riscv/boot/dts/sophgo/sg2002-milkv-duo256m.dts
+++ b/arch/riscv/boot/dts/sophgo/sg2002-milkv-duo256m.dts
@@ -49,6 +49,14 @@ coprocessor_rtos: region@8fe00000 {
 	};
 };
 
+&gmac0 {
+	status = "okay";
+};
+
+&mdio {
+	status = "okay";
+};
+
 &osc {
 	clock-frequency = <25000000>;
 };

base-commit: 11881041b745b444e4f6c87a2748f1951cf02742
-- 
2.43.0

Re: [PATCH 1/2] riscv: dts: sophgo: Enable ethernet for Milk-V Duo 256M

[Inochi Amaoto]

On Tue, Aug 04, 2026 at 12:33:18AM +0800, Chen-Yu Yeh wrote:
> The SG2002 has an internal ethernet PHY, but on the Milk-V Duo 256M the
> ethernet signals are only routed to the RJ45 connector of the optional
> IO board.
> 
> Enable the GMAC and the MDIO multiplexer so that the interface is usable
> when such a board is attached.
> 
> Tested on actual Milk-V Duo 256M hardware: the GMAC probes, the MDIO
> multiplexer selects the internal bus and the internal EPHY is detected
> at address 1:
> 
>   eth0: PHY [mdio_mux-0.0:01] driver [Generic PHY]
> 

> Link-up was not verified for lack of the IO board.
> 

This is not acceptable, I agree with something like DT overlay for
support external IO board to enable this. But you should not enable
this by default. As other may want to use this as GPIO.

Regards,
Inochi

> Signed-off-by: Chen-Yu Yeh <chenyou910331@gmail.com>
> ---
>  arch/riscv/boot/dts/sophgo/sg2002-milkv-duo256m.dts | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/arch/riscv/boot/dts/sophgo/sg2002-milkv-duo256m.dts b/arch/riscv/boot/dts/sophgo/sg2002-milkv-duo256m.dts
> index a2797c0bd767..1462a96a1c12 100644
> --- a/arch/riscv/boot/dts/sophgo/sg2002-milkv-duo256m.dts
> +++ b/arch/riscv/boot/dts/sophgo/sg2002-milkv-duo256m.dts
> @@ -49,6 +49,14 @@ coprocessor_rtos: region@8fe00000 {
>  	};
>  };
>  
> +&gmac0 {
> +	status = "okay";
> +};
> +
> +&mdio {
> +	status = "okay";
> +};
> +
>  &osc {
>  	clock-frequency = <25000000>;
>  };
> 
> base-commit: 11881041b745b444e4f6c87a2748f1951cf02742
> -- 
> 2.43.0
>