[PATCH v8 1/4] arm64: dts: allwinner: orange-pi-3: Enable ethernet

[megous at megous.com]

From: Ondrej Jirman <megous at megous.com>

Orange Pi 3 has two regulators that power the Realtek RTL8211E. According
to the phy datasheet, both regulators need to be enabled at the same time,
but we can only specify a single phy-supply in the DT.

This can be achieved by making one regulator depedning on the other via
vin-supply. While it's not a technically correct description of the
hardware, it achieves the purpose.

All values of RX/TX delay were tested exhaustively and a middle one of the
working values was chosen.

Signed-off-by: Ondrej Jirman <megous at megous.com>
---
 .../dts/allwinner/sun50i-h6-orangepi-3.dts    | 44 +++++++++++++++++++
 1 file changed, 44 insertions(+)

diff --git a/arch/arm64/boot/dts/allwinner/sun50i-h6-orangepi-3.dts b/arch/arm64/boot/dts/allwinner/sun50i-h6-orangepi-3.dts
index 17d496990108..2c6807b74ff6 100644
--- a/arch/arm64/boot/dts/allwinner/sun50i-h6-orangepi-3.dts
+++ b/arch/arm64/boot/dts/allwinner/sun50i-h6-orangepi-3.dts
@@ -15,6 +15,7 @@
 
 	aliases {
 		serial0 = &uart0;
+		ethernet0 = &emac;
 	};
 
 	chosen {
@@ -44,6 +45,27 @@
 		regulator-max-microvolt = <5000000>;
 		regulator-always-on;
 	};
+
+	/*
+	 * The board uses 2.5V RGMII signalling. Power sequence to enable
+	 * the phy is to enable GMAC-2V5 and GMAC-3V (aldo2) power rails
+	 * at the same time and to wait 100ms.
+	 */
+	reg_gmac_2v5: gmac-2v5 {
+		compatible = "regulator-fixed";
+		regulator-name = "gmac-2v5";
+		regulator-min-microvolt = <2500000>;
+		regulator-max-microvolt = <2500000>;
+		startup-delay-us = <100000>;
+		enable-active-high;
+		gpio = <&pio 3 6 GPIO_ACTIVE_HIGH>; /* PD6 */
+
+		/* The real parent of gmac-2v5 is reg_vcc5v, but we need to
+		 * enable two regulators to power the phy. This is one way
+		 * to achieve that.
+		 */
+		vin-supply = <&reg_aldo2>; /* GMAC-3V */
+	};
 };
 
 &cpu0 {
@@ -58,6 +80,28 @@
 	status = "okay";
 };
 
+&emac {
+	pinctrl-names = "default";
+	pinctrl-0 = <&ext_rgmii_pins>;
+	phy-mode = "rgmii";
+	phy-handle = <&ext_rgmii_phy>;
+	phy-supply = <&reg_gmac_2v5>;
+	allwinner,rx-delay-ps = <1500>;
+	allwinner,tx-delay-ps = <700>;
+	status = "okay";
+};
+
+&mdio {
+	ext_rgmii_phy: ethernet-phy at 1 {
+		compatible = "ethernet-phy-ieee802.3-c22";
+		reg = <1>;
+
+		reset-gpios = <&pio 3 14 GPIO_ACTIVE_LOW>; /* PD14 */
+		reset-assert-us = <15000>;
+		reset-deassert-us = <40000>;
+	};
+};
+
 &mmc0 {
 	vmmc-supply = <&reg_cldo1>;
 	cd-gpios = <&pio 5 6 GPIO_ACTIVE_LOW>; /* PF6 */
-- 
2.22.0