From: Chen-Yu Tsai <wens@csie.org>

On the Orangepi 4A board, the second Ethernet controller, aka the GMAC200,
is connected to an external Motorcomm YT8531 PHY. The PHY uses an external
25MHz crystal, has the SoC's PI15 pin connected to its reset pin, and
the PI16 pin for its interrupt pin.

Enable it.

Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
---

Changes since v1:
- Switch to generic (tx|rx)-internal-delay-ps properties
---
 .../dts/allwinner/sun55i-t527-orangepi-4a.dts | 23 +++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/arch/arm64/boot/dts/allwinner/sun55i-t527-orangepi-4a.dts b/arch/arm64/boot/dts/allwinner/sun55i-t527-orangepi-4a.dts
index 38cd8c7e92da..7afd6e57fe86 100644
--- a/arch/arm64/boot/dts/allwinner/sun55i-t527-orangepi-4a.dts
+++ b/arch/arm64/boot/dts/allwinner/sun55i-t527-orangepi-4a.dts
@@ -15,6 +15,7 @@ / {
 	compatible = "xunlong,orangepi-4a", "allwinner,sun55i-t527";
 
 	aliases {
+		ethernet0 = &gmac1;
 		serial0 = &uart0;
 	};
 
@@ -95,11 +96,33 @@ &ehci1 {
 	status = "okay";
 };
 
+&gmac1 {
+	phy-mode = "rgmii-id";
+	phy-handle = <&ext_rgmii_phy>;
+	phy-supply = <&reg_cldo4>;
+
+	tx-internal-delay-ps = <0>;
+	rx-internal-delay-ps = <300>;
+
+	status = "okay";
+};
+
 &gpu {
 	mali-supply = <&reg_dcdc2>;
 	status = "okay";
 };
 
+&mdio1 {
+	ext_rgmii_phy: ethernet-phy@1 {
+		compatible = "ethernet-phy-ieee802.3-c22";
+		reg = <1>;
+		interrupts-extended = <&pio 8 16 IRQ_TYPE_LEVEL_LOW>; /* PI16 */
+		reset-gpios = <&pio 8 15 GPIO_ACTIVE_LOW>; /* PI15 */
+		reset-assert-us = <10000>;
+		reset-deassert-us = <150000>;
+	};
+};
+
 &mmc0 {
 	vmmc-supply = <&reg_cldo3>;
 	cd-gpios = <&pio 5 6 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>; /* PF6 */
-- 
2.39.5

On Fri, Sep 12, 2025 at 01:40:32AM +0800, Chen-Yu Tsai wrote:
> From: Chen-Yu Tsai <wens@csie.org>
> 
> On the Orangepi 4A board, the second Ethernet controller, aka the GMAC200,
> is connected to an external Motorcomm YT8531 PHY. The PHY uses an external
> 25MHz crystal, has the SoC's PI15 pin connected to its reset pin, and
> the PI16 pin for its interrupt pin.
> 
> Enable it.
> 
> Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
> Signed-off-by: Chen-Yu Tsai <wens@csie.org>

Reviewed-by: Andrew Lunn <andrew@lunn.ch>

    Andrew