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.

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 d07bb9193b43..b604d961c4fd 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