arm64: dts: renesas: Add HiHope RZ/G2M sub board support

The HiHope RZ/G2M sub board sits below the HiHope RZ/G2M main board.
This patch also adds ethernet support along with a dtsi common to
both HiHope RZ/G2M and RZ/G2N sub boards.
Signed-off-by: Biju Das <biju.das@bp.renesas.com>
Reviewed-by: Chris Paterson <Chris.Paterson2@renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm64/boot/dts/renesas/Makefile

 # SPDX-License-Identifier: GPL-2.0
 dtb-$(CONFIG_ARCH_R8A774A1) += r8a774a1-hihope-rzg2m.dtb
+dtb-$(CONFIG_ARCH_R8A774A1) += r8a774a1-hihope-rzg2m-ex.dtb
 dtb-$(CONFIG_ARCH_R8A774C0) += r8a774c0-cat874.dtb r8a774c0-ek874.dtb
 dtb-$(CONFIG_ARCH_R8A7795) += r8a7795-salvator-x.dtb r8a7795-h3ulcb.dtb
 dtb-$(CONFIG_ARCH_R8A7795) += r8a7795-h3ulcb-kf.dtb

arch/arm64/boot/dts/renesas/hihope-common.dtsi

@@ -5,6 +5,8 @@
  * Copyright (C) 2019 Renesas Electronics Corp.
  */
 
+#include <dt-bindings/gpio/gpio.h>
+
 / {
 	aliases {
 		serial0 = &scif2;

arch/arm64/boot/dts/renesas/hihope-rzg2-ex.dtsi

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Device Tree Source for the RZ/G2[MN] HiHope sub board common parts
+ *
+ * Copyright (C) 2019 Renesas Electronics Corp.
+ */
+
+/ {
+	aliases {
+		ethernet0 = &avb;
+	};
+
+	chosen {
+		bootargs = "ignore_loglevel rw root=/dev/nfs ip=on";
+	};
+};
+
+&avb {
+	pinctrl-0 = <&avb_pins>;
+	pinctrl-names = "default";
+	phy-handle = <&phy0>;
+	phy-mode = "rgmii-txid";
+	status = "okay";
+
+	phy0: ethernet-phy@0 {
+		rxc-skew-ps = <1500>;
+		reg = <0>;
+		interrupt-parent = <&gpio2>;
+		interrupts = <11 IRQ_TYPE_LEVEL_LOW>;
+		reset-gpios = <&gpio2 10 GPIO_ACTIVE_LOW>;
+	};
+};
+
+&pfc {
+	pinctrl-0 = <&scif_clk_pins>;
+	pinctrl-names = "default";
+
+	avb_pins: avb {
+		mux {
+			groups = "avb_link", "avb_mdio", "avb_mii";
+			function = "avb";
+		};
+
+		pins_mdio {
+			groups = "avb_mdio";
+			drive-strength = <24>;
+		};
+
+		pins_mii_tx {
+			pins = "PIN_AVB_TX_CTL", "PIN_AVB_TXC", "PIN_AVB_TD0",
+			       "PIN_AVB_TD1", "PIN_AVB_TD2", "PIN_AVB_TD3";
+			drive-strength = <12>;
+		};
+	};
+};

arch/arm64/boot/dts/renesas/r8a774a1-hihope-rzg2m-ex.dts

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Device Tree Source for the HiHope RZ/G2M sub board
+ *
+ * Copyright (C) 2019 Renesas Electronics Corp.
+ */
+
+#include "r8a774a1-hihope-rzg2m.dts"
+#include "hihope-rzg2-ex.dtsi"
+
+/ {
+	model = "HopeRun HiHope RZ/G2M with sub board";
+	compatible = "hoperun,hihope-rzg2-ex", "hoperun,hihope-rzg2m",
+		     "renesas,r8a774a1";
+};