[PATCH v3 7/8] arm64: dts: amlogic: t7: khadas-vim4: enable the ethernet port

The board carries a Realtek RTL8211F gigabit PHY on the external
management bus, connected to the MAC over RGMII.

Enable the controller, hand it the ethernet pins and point it at the
PHY. RGMII needs a delay on each of its two clocks, and on this board
both come from inside the chips, not from the board traces. The PHY
adds the one on receive. Its transmit delay does not work here, so the
controller adds that one.

The PHY interrupt output is wired to GPIOH_6, so link changes are
reported instead of polled. The PHY reset is an RC network on the
board, not a SoC pin, so there is no reset line to describe.

Assisted-by: LLM
Signed-off-by: Lucas Tanure <redacted>
---
 .../amlogic/amlogic-t7-a311d2-khadas-vim4.dts | 20 +++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/arch/arm64/boot/dts/amlogic/amlogic-t7-a311d2-khadas-vim4.dts b/arch/arm64/boot/dts/amlogic/amlogic-t7-a311d2-khadas-vim4.dts
index 0fa83362b417..c18bde02ac40 100644
--- a/arch/arm64/boot/dts/amlogic/amlogic-t7-a311d2-khadas-vim4.dts
+++ b/arch/arm64/boot/dts/amlogic/amlogic-t7-a311d2-khadas-vim4.dts

@@ -14,6 +14,7 @@ / {
 	compatible = "khadas,vim4", "amlogic,a311d2", "amlogic,t7";
 
 	aliases {
+		ethernet0 = &ethmac;
 		serial0 = &uart_a;
 		mmc0 = &sd_emmc_c;
 		mmc1 = &sd_emmc_b;

@@ -256,6 +257,25 @@ xtal: xtal-clk {
 	};
 };
 
+&ethmac {
+	status = "okay";
+	pinctrl-0 = <&eth_pins>, <&eth_rgmii_pins>;
+	pinctrl-names = "default";
+	phy-mode = "rgmii-id";
+	phy-handle = <&external_phy>;
+	tx-internal-delay-ps = <2000>;
+};
+
+&ext_mdio {
+	external_phy: ethernet-phy@0 {
+		/* Realtek RTL8211FD-CG */
+		reg = <0>;
+
+		interrupt-parent = <&gpio_intc>;
+		interrupts = <GPIOH_6 IRQ_TYPE_LEVEL_LOW>;
+	};
+};
+
 &i2c_m_ao_a {
 	status = "okay";
 	pinctrl-0 = <&i2c0_ao_d_pins>;

-- 
2.56.0