arm64: dts: add support for A4 based Amlogic BA400

Amlogic A4 is an application processor designed for smart audio
and IoT applications.

Add basic support for the A4 based Amlogic BA400 board, which describes
the following components: CPU, GIC, IRQ, Timer and UART.
These are capable of booting up into the serial console.
Signed-off-by: Xianwei Zhao <xianwei.zhao@amlogic.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20240401-basic_dt-v3-4-cb29ae1c16da@amlogic.comSigned-off-by: Neil Armstrong <neil.armstrong@linaro.org>

arch/arm64/boot/dts/amlogic/Makefile

 # SPDX-License-Identifier: GPL-2.0
+dtb-$(CONFIG_ARCH_MESON) += amlogic-a4-a113l2-ba400.dtb
 dtb-$(CONFIG_ARCH_MESON) += amlogic-c3-c302x-aw409.dtb
 dtb-$(CONFIG_ARCH_MESON) += amlogic-t7-a311d2-an400.dtb
 dtb-$(CONFIG_ARCH_MESON) += amlogic-t7-a311d2-khadas-vim4.dtb

arch/arm64/boot/dts/amlogic/amlogic-a4-a113l2-ba400.dts

+// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+/*
+ * Copyright (c) 2024 Amlogic, Inc. All rights reserved.
+ */
+
+/dts-v1/;
+
+#include "amlogic-a4.dtsi"
+
+/ {
+	model = "Amlogic A113L2 ba400 Development Board";
+	compatible = "amlogic,ba400", "amlogic,a4";
+	interrupt-parent = <&gic>;
+	#address-cells = <2>;
+	#size-cells = <2>;
+
+	aliases {
+		serial0 = &uart_b;
+	};
+
+	memory@0 {
+		device_type = "memory";
+		reg = <0x0 0x0 0x0 0x40000000>;
+	};
+
+	reserved-memory {
+		#address-cells = <2>;
+		#size-cells = <2>;
+		ranges;
+
+		/* 10 MiB reserved for ARM Trusted Firmware */
+		secmon_reserved: secmon@5000000 {
+			compatible = "shared-dma-pool";
+			reg = <0x0 0x05000000 0x0 0xa00000>;
+			no-map;
+		};
+	};
+};
+
+&uart_b {
+	status = "okay";
+};

arch/arm64/boot/dts/amlogic/amlogic-a4-common.dtsi

+// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+/*
+ * Copyright (c) 2024 Amlogic, Inc. All rights reserved.
+ */
+
+#include <dt-bindings/interrupt-controller/irq.h>
+#include <dt-bindings/interrupt-controller/arm-gic.h>
+#include <dt-bindings/gpio/gpio.h>
+/ {
+	timer {
+		compatible = "arm,armv8-timer";
+		interrupts = <GIC_PPI 13 (GIC_CPU_MASK_SIMPLE(4) | IRQ_TYPE_LEVEL_LOW)>,
+			     <GIC_PPI 14 (GIC_CPU_MASK_SIMPLE(4) | IRQ_TYPE_LEVEL_LOW)>,
+			     <GIC_PPI 11 (GIC_CPU_MASK_SIMPLE(4) | IRQ_TYPE_LEVEL_LOW)>,
+			     <GIC_PPI 10 (GIC_CPU_MASK_SIMPLE(4) | IRQ_TYPE_LEVEL_LOW)>;
+	};
+
+	psci {
+		compatible = "arm,psci-1.0";
+		method = "smc";
+	};
+
+	xtal: xtal-clk {
+		compatible = "fixed-clock";
+		clock-frequency = <24000000>;
+		clock-output-names = "xtal";
+		#clock-cells = <0>;
+	};
+
+	soc {
+		compatible = "simple-bus";
+		#address-cells = <2>;
+		#size-cells = <2>;
+		ranges;
+
+		gic: interrupt-controller@fff01000 {
+			compatible = "arm,gic-400";
+			reg = <0x0 0xfff01000 0 0x1000>,
+			      <0x0 0xfff02000 0 0x2000>,
+			      <0x0 0xfff04000 0 0x2000>,
+			      <0x0 0xfff06000 0 0x2000>;
+			#interrupt-cells = <3>;
+			#address-cells = <0>;
+			interrupt-controller;
+			interrupts = <GIC_PPI 9 (GIC_CPU_MASK_SIMPLE(4) | IRQ_TYPE_LEVEL_HIGH)>;
+		};
+
+		apb: bus@fe000000 {
+			compatible = "simple-bus";
+			reg = <0x0 0xfe000000 0x0 0x480000>;
+			#address-cells = <2>;
+			#size-cells = <2>;
+			ranges = <0x0 0x0 0x0 0xfe000000 0x0 0x480000>;
+
+			uart_b: serial@7a000 {
+				compatible = "amlogic,a4-uart",
+					     "amlogic,meson-s4-uart";
+				reg = <0x0 0x7a000 0x0 0x18>;
+				interrupts = <GIC_SPI 169 IRQ_TYPE_EDGE_RISING>;
+				clocks = <&xtal>, <&xtal>, <&xtal>;
+				clock-names = "xtal", "pclk", "baud";
+				status = "disabled";
+			};
+		};
+	};
+};

arch/arm64/boot/dts/amlogic/amlogic-a4.dtsi

+// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+/*
+ * Copyright (c) 2024 Amlogic, Inc. All rights reserved.
+ */
+
+#include "amlogic-a4-common.dtsi"
+/ {
+	cpus {
+		#address-cells = <2>;
+		#size-cells = <0>;
+
+		cpu0: cpu@0 {
+			device_type = "cpu";
+			compatible = "arm,cortex-a53";
+			reg = <0x0 0x0>;
+			enable-method = "psci";
+		};
+
+		cpu1: cpu@1 {
+			device_type = "cpu";
+			compatible = "arm,cortex-a53";
+			reg = <0x0 0x1>;
+			enable-method = "psci";
+		};
+
+		cpu2: cpu@2 {
+			device_type = "cpu";
+			compatible = "arm,cortex-a53";
+			reg = <0x0 0x2>;
+			enable-method = "psci";
+		};
+
+		cpu3: cpu@3 {
+			device_type = "cpu";
+			compatible = "arm,cortex-a53";
+			reg = <0x0 0x3>;
+			enable-method = "psci";
+		};
+	};
+};