arm64: dts: meson-g12a: add initial g12a s905d2 SoC DT support

Try to add basic DT support for the Amlogic's Meson-G12A S905D2 SoC,
which describe components as follows: Reserve Memory, CPU, GIC, IRQ,
Timer, UART. It's capable of booting up into the serial console.
Signed-off-by: NJianxin Pan <jianxin.pan@amlogic.com>
Reviewed-by: NJerome Brunet <jbrunet@baylibre.com>
Reviewed-by: NNeil Armstrong <narmstrong@baylibre.com>
Signed-off-by: NKevin Hilman <khilman@baylibre.com>

arch/arm64/boot/dts/amlogic/Makefile

 # SPDX-License-Identifier: GPL-2.0
 dtb-$(CONFIG_ARCH_MESON) += meson-axg-s400.dtb
+dtb-$(CONFIG_ARCH_MESON) += meson-g12a-u200.dtb
 dtb-$(CONFIG_ARCH_MESON) += meson-gxbb-nanopi-k2.dtb
 dtb-$(CONFIG_ARCH_MESON) += meson-gxbb-nexbox-a95x.dtb
 dtb-$(CONFIG_ARCH_MESON) += meson-gxbb-odroidc2.dtb

arch/arm64/boot/dts/amlogic/meson-g12a-u200.dts

+// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+/*
+ * Copyright (c) 2018 Amlogic, Inc. All rights reserved.
+ */
+
+/dts-v1/;
+
+#include "meson-g12a.dtsi"
+
+/ {
+	compatible = "amlogic,u200", "amlogic,g12a";
+	model = "Amlogic Meson G12A U200 Development Board";
+
+	aliases {
+		serial0 = &uart_AO;
+	};
+	chosen {
+		stdout-path = "serial0:115200n8";
+	};
+	memory@0 {
+		device_type = "memory";
+		reg = <0x0 0x0 0x0 0x40000000>;
+	};
+};
+
+&uart_AO {
+	status = "okay";
+};
+

arch/arm64/boot/dts/amlogic/meson-g12a.dtsi

+// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+/*
+ * Copyright (c) 2018 Amlogic, Inc. All rights reserved.
+ */
+
+#include <dt-bindings/gpio/gpio.h>
+#include <dt-bindings/interrupt-controller/irq.h>
+#include <dt-bindings/interrupt-controller/arm-gic.h>
+
+/ {
+	compatible = "amlogic,g12a";
+
+	interrupt-parent = <&gic>;
+	#address-cells = <2>;
+	#size-cells = <2>;
+
+	cpus {
+		#address-cells = <0x2>;
+		#size-cells = <0x0>;
+
+		cpu0: cpu@0 {
+			device_type = "cpu";
+			compatible = "arm,cortex-a53", "arm,armv8";
+			reg = <0x0 0x0>;
+			enable-method = "psci";
+			next-level-cache = <&l2>;
+		};
+
+		cpu1: cpu@1 {
+			device_type = "cpu";
+			compatible = "arm,cortex-a53", "arm,armv8";
+			reg = <0x0 0x1>;
+			enable-method = "psci";
+			next-level-cache = <&l2>;
+		};
+
+		cpu2: cpu@2 {
+			device_type = "cpu";
+			compatible = "arm,cortex-a53", "arm,armv8";
+			reg = <0x0 0x2>;
+			enable-method = "psci";
+			next-level-cache = <&l2>;
+		};
+
+		cpu3: cpu@3 {
+			device_type = "cpu";
+			compatible = "arm,cortex-a53", "arm,armv8";
+			reg = <0x0 0x3>;
+			enable-method = "psci";
+			next-level-cache = <&l2>;
+		};
+
+		l2: l2-cache0 {
+			compatible = "cache";
+		};
+	};
+
+	psci {
+		compatible = "arm,psci-1.0";
+		method = "smc";
+	};
+
+	reserved-memory {
+		#address-cells = <2>;
+		#size-cells = <2>;
+		ranges;
+
+		/* 3 MiB reserved for ARM Trusted Firmware (BL31) */
+		secmon_reserved: secmon@5000000 {
+			reg = <0x0 0x05000000 0x0 0x300000>;
+			no-map;
+		};
+	};
+
+	soc {
+		compatible = "simple-bus";
+		#address-cells = <2>;
+		#size-cells = <2>;
+		ranges;
+
+		periphs: periphs@ff634000 {
+			compatible = "simple-bus";
+			reg = <0x0 0xff634000 0x0 0x2000>;
+			#address-cells = <2>;
+			#size-cells = <2>;
+			ranges = <0x0 0x0 0x0 0xff634000 0x0 0x2000>;
+		};
+
+		hiubus: bus@ff63c000 {
+			compatible = "simple-bus";
+			reg = <0x0 0xff63c000 0x0 0x1c00>;
+			#address-cells = <2>;
+			#size-cells = <2>;
+			ranges = <0x0 0x0 0x0 0xff63c000 0x0 0x1c00>;
+		};
+
+		aobus: bus@ff800000 {
+			compatible = "simple-bus";
+			reg = <0x0 0xff800000 0x0 0x100000>;
+			#address-cells = <2>;
+			#size-cells = <2>;
+			ranges = <0x0 0x0 0x0 0xff800000 0x0 0x100000>;
+
+			uart_AO: serial@3000 {
+				compatible = "amlogic,meson-gx-uart", "amlogic,meson-ao-uart";
+				reg = <0x0 0x3000 0x0 0x18>;
+				interrupts = <GIC_SPI 193 IRQ_TYPE_EDGE_RISING>;
+				clocks = <&xtal>, <&xtal>, <&xtal>;
+				clock-names = "xtal", "pclk", "baud";
+				status = "disabled";
+			};
+
+			uart_AO_B: serial@4000 {
+				compatible = "amlogic,meson-gx-uart", "amlogic,meson-ao-uart";
+				reg = <0x0 0x4000 0x0 0x18>;
+				interrupts = <GIC_SPI 197 IRQ_TYPE_EDGE_RISING>;
+				clocks = <&xtal>, <&xtal>, <&xtal>;
+				clock-names = "xtal", "pclk", "baud";
+				status = "disabled";
+			};
+		};
+
+		gic: interrupt-controller@ffc01000 {
+			compatible = "arm,gic-400";
+			reg = <0x0 0xffc01000 0 0x1000>,
+			      <0x0 0xffc02000 0 0x2000>,
+			      <0x0 0xffc04000 0 0x2000>,
+			      <0x0 0xffc06000 0 0x2000>;
+			interrupt-controller;
+			interrupts = <GIC_PPI 9
+				(GIC_CPU_MASK_SIMPLE(8) | IRQ_TYPE_LEVEL_HIGH)>;
+			#interrupt-cells = <3>;
+			#address-cells = <0>;
+		};
+
+		cbus: bus@ffd00000 {
+			compatible = "simple-bus";
+			reg = <0x0 0xffd00000 0x0 0x25000>;
+			#address-cells = <2>;
+			#size-cells = <2>;
+			ranges = <0x0 0x0 0x0 0xffd00000 0x0 0x25000>;
+		};
+
+		apb: apb@ffe00000 {
+			compatible = "simple-bus";
+			reg = <0x0 0xffe00000 0x0 0x200000>;
+			#address-cells = <2>;
+			#size-cells = <2>;
+			ranges = <0x0 0x0 0x0 0xffe00000 0x0 0x200000>;
+		};
+	};
+
+	timer {
+		compatible = "arm,armv8-timer";
+		interrupts = <GIC_PPI 13
+			(GIC_CPU_MASK_RAW(0xff) | IRQ_TYPE_LEVEL_LOW)>,
+			     <GIC_PPI 14
+			(GIC_CPU_MASK_RAW(0xff) | IRQ_TYPE_LEVEL_LOW)>,
+			     <GIC_PPI 11
+			(GIC_CPU_MASK_RAW(0xff) | IRQ_TYPE_LEVEL_LOW)>,
+			     <GIC_PPI 10
+			(GIC_CPU_MASK_RAW(0xff) | IRQ_TYPE_LEVEL_LOW)>;
+	};
+
+	xtal: xtal-clk {
+		compatible = "fixed-clock";
+		clock-frequency = <24000000>;
+		clock-output-names = "xtal";
+		#clock-cells = <0>;
+	};
+
+};