ARM: sun8i: bananapi-m2-plus: Enable dwmac-sun8i

The dwmac-sun8i hardware is present on the Banana Pi M2+
It uses an external PHY rtl8211e via RGMII.

This patch create the needed regulator, emac and phy nodes.
Signed-off-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

arch/arm/boot/dts/sun8i-h3-bananapi-m2-plus.dts

@@ -52,6 +52,7 @@ / {
 	compatible = "sinovoip,bpi-m2-plus", "allwinner,sun8i-h3";
 
 	aliases {
+		ethernet0 = &emac;
 		serial0 = &uart0;
 		serial1 = &uart1;
 	};
@@ -84,6 +85,16 @@ sw4 {
 		};
 	};
 
+	reg_gmac_3v3: gmac-3v3 {
+		      compatible = "regulator-fixed";
+		      regulator-name = "gmac-3v3";
+		      regulator-min-microvolt = <3300000>;
+		      regulator-max-microvolt = <3300000>;
+		      startup-delay-us = <100000>;
+		      enable-active-high;
+		      gpio = <&pio 3 6 GPIO_ACTIVE_HIGH>;
+	};
+
 	wifi_pwrseq: wifi_pwrseq {
 		compatible = "mmc-pwrseq-simple";
 		pinctrl-names = "default";
@@ -100,12 +111,30 @@ &ehci2 {
 	status = "okay";
 };
 
+&emac {
+	pinctrl-names = "default";
+	pinctrl-0 = <&emac_rgmii_pins>;
+	phy-supply = <&reg_gmac_3v3>;
+	phy-handle = <&ext_rgmii_phy>;
+	phy-mode = "rgmii";
+
+	allwinner,leds-active-low;
+	status = "okay";
+};
+
 &ir {
 	pinctrl-names = "default";
 	pinctrl-0 = <&ir_pins_a>;
 	status = "okay";
 };
 
+&mdio {
+	ext_rgmii_phy: ethernet-phy@1 {
+		compatible = "ethernet-phy-ieee802.3-c22";
+		reg = <0>;
+	};
+};
+
 &mmc0 {
 	pinctrl-names = "default";
 	pinctrl-0 = <&mmc0_pins_a>, <&mmc0_cd_pin>;