ARM: dts: sun8i: a83t: add dwmac-sun8i device node

The dwmac-sun8i is an ethernet MAC hardware that support 10/100/1000 speed.
This patch add support for it on the Allwinner a83t SoC Device-tree.

This patch add the emac device node and the related RGMII pins node.
Signed-off-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

arch/arm/boot/dts/sun8i-a83t.dtsi

@@ -336,6 +336,18 @@ pio: pinctrl@1c20800 {
 			#interrupt-cells = <3>;
 			#gpio-cells = <3>;
 
+			emac_rgmii_pins: emac-rgmii-pins {
+				pins = "PD2", "PD3", "PD4", "PD5", "PD6", "PD7",
+				       "PD11", "PD12", "PD13", "PD14", "PD18",
+				       "PD19", "PD21", "PD22", "PD23";
+				function = "gmac";
+				/*
+				 * data lines in RGMII mode use DDR mode
+				 * and need a higher signal drive strength
+				 */
+				drive-strength = <40>;
+			};
+
 			mmc0_pins: mmc0-pins {
 				pins = "PF0", "PF1", "PF2",
 				       "PF3", "PF4", "PF5";
@@ -440,6 +452,27 @@ uart1: serial@1c28400 {
 			status = "disabled";
 		};
 
+		emac: ethernet@1c30000 {
+			compatible = "allwinner,sun8i-a83t-emac";
+			syscon = <&syscon>;
+			reg = <0x01c30000 0x104>;
+			interrupts = <GIC_SPI 82 IRQ_TYPE_LEVEL_HIGH>;
+			interrupt-names = "macirq";
+			resets = <&ccu 13>;
+			reset-names = "stmmaceth";
+			clocks = <&ccu 27>;
+			clock-names = "stmmaceth";
+			#address-cells = <1>;
+			#size-cells = <0>;
+			status = "disabled";
+
+			mdio: mdio {
+				compatible = "snps,dwmac-mdio";
+				#address-cells = <1>;
+				#size-cells = <0>;
+			};
+		};
+
 		gic: interrupt-controller@1c81000 {
 			compatible = "arm,cortex-a7-gic", "arm,cortex-a15-gic";
 			reg = <0x01c81000 0x1000>,