[PATCH v2 2/3] arm64: dts: rockchip: Split out the common NanoPi RK3528 parts

[Andrey Korshunov]

On Mon Sep 7, 2026 at 4:13 PM CEST, 安容 via B4 Relay wrote:
> +&mdio1 {
> +	rgmii_phy: ethernet-phy at 1 {
> +		compatible = "ethernet-phy-ieee802.3-c22";
> +		reg = <0x1>;
> +		pinctrl-names = "default";
> +		pinctrl-0 = <&gmac1_rstn_l>;
> +		reset-assert-us = <20000>;
> +		reset-deassert-us = <100000>;
> +		reset-gpios = <&gpio4 RK_PC2 GPIO_ACTIVE_LOW>;
> +	};
> +};

This is carried over unchanged from the NanoPi Zero2, so not something
this patch introduces, but it is worth fixing while the node is being
moved, because as written the port depends on the bootloader.

of_mdio_bus_register() reads the PHY ID with get_phy_device() before
phy_device_register() fetches the PHY node's reset-gpios, so a PHY that
the bootloader left in reset is simply not found:

  mdio_bus stmmac-0: MDIO device at address 1 is missing.

I hit exactly that on a NanoPi R28S booted with mainline U-Boot
(generic-rk3528), which does not touch that pin - the RGMII port never
came up. Describing the reset on the MAC instead makes stmmac install it
as mii_bus->reset, which runs before the bus is scanned:

	&gmac1 {
		snps,reset-active-low;
		snps,reset-delays-us = <0 20000 100000>;
		snps,reset-gpio = <&gpio4 RK_PC2 GPIO_ACTIVE_LOW>;
	};

with &gmac1_rstn_l moved to the MAC's pinctrl-0 and the three reset
properties dropped from the PHY node. Then the port comes up whatever
the bootloader did, on both boards. Armbian carries the same change for
the NanoPi Zero2, for the same reason.

I had an R28S series of my own out before I saw yours; I am dropping it.
Happy to test this one on the hardware and send a Tested-by.

Andrey