arm64: dts: mediatek: Add initial MT7981B and Xiaomi AX3000T

MT7981B (AKA MediaTek Filogic 820) is a dual-core ARM Cortex-A53 SoC.
One of market devices using this SoC is Xiaomi AX3000T.

This is initial contribution with basic SoC support. More hardware block
will get added later. Some will need their bindings (like auxadc).
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20240111103928.721-3-zajec5@gmail.comSigned-off-by: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>

arch/arm64/boot/dts/mediatek/Makefile

@@ -8,6 +8,7 @@ dtb-$(CONFIG_ARCH_MEDIATEK) += mt6797-evb.dtb
 dtb-$(CONFIG_ARCH_MEDIATEK) += mt6797-x20-dev.dtb
 dtb-$(CONFIG_ARCH_MEDIATEK) += mt7622-rfb1.dtb
 dtb-$(CONFIG_ARCH_MEDIATEK) += mt7622-bananapi-bpi-r64.dtb
+dtb-$(CONFIG_ARCH_MEDIATEK) += mt7981b-xiaomi-ax3000t.dtb
 dtb-$(CONFIG_ARCH_MEDIATEK) += mt7986a-bananapi-bpi-r3.dtb
 dtb-$(CONFIG_ARCH_MEDIATEK) += mt7986a-bananapi-bpi-r3-emmc.dtbo
 dtb-$(CONFIG_ARCH_MEDIATEK) += mt7986a-bananapi-bpi-r3-nand.dtbo

arch/arm64/boot/dts/mediatek/mt7981b-xiaomi-ax3000t.dts

+// SPDX-License-Identifier: GPL-2.0-only OR MIT
+
+/dts-v1/;
+
+#include "mt7981b.dtsi"
+
+/ {
+	compatible = "xiaomi,ax3000t", "mediatek,mt7981b";
+	model = "Xiaomi AX3000T";
+
+	memory@40000000 {
+		reg = <0 0x40000000 0 0x10000000>;
+		device_type = "memory";
+	};
+};

arch/arm64/boot/dts/mediatek/mt7981b.dtsi

+// SPDX-License-Identifier: GPL-2.0-only OR MIT
+
+#include <dt-bindings/clock/mediatek,mt7981-clk.h>
+#include <dt-bindings/interrupt-controller/arm-gic.h>
+
+/ {
+	compatible = "mediatek,mt7981b";
+	interrupt-parent = <&gic>;
+	#address-cells = <2>;
+	#size-cells = <2>;
+
+	cpus {
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		cpu@0 {
+			compatible = "arm,cortex-a53";
+			reg = <0x0>;
+			device_type = "cpu";
+			enable-method = "psci";
+		};
+
+		cpu@1 {
+			compatible = "arm,cortex-a53";
+			reg = <0x1>;
+			device_type = "cpu";
+			enable-method = "psci";
+		};
+	};
+
+	oscillator-40m {
+		compatible = "fixed-clock";
+		clock-frequency = <40000000>;
+		clock-output-names = "clkxtal";
+		#clock-cells = <0>;
+	};
+
+	psci {
+		compatible = "arm,psci-1.0";
+		method = "smc";
+	};
+
+	soc {
+		compatible = "simple-bus";
+		ranges;
+		#address-cells = <2>;
+		#size-cells = <2>;
+
+		gic: interrupt-controller@c000000 {
+			compatible = "arm,gic-v3";
+			reg = <0 0x0c000000 0 0x40000>,  /* GICD */
+			      <0 0x0c080000 0 0x200000>; /* GICR */
+			interrupt-parent = <&gic>;
+			interrupts = <GIC_PPI 9 IRQ_TYPE_LEVEL_HIGH>;
+			interrupt-controller;
+			#interrupt-cells = <3>;
+		};
+
+		infracfg: clock-controller@10001000 {
+			compatible = "mediatek,mt7981-infracfg", "syscon";
+			reg = <0 0x10001000 0 0x1000>;
+			#clock-cells = <1>;
+		};
+
+		clock-controller@1001b000 {
+			compatible = "mediatek,mt7981-topckgen", "syscon";
+			reg = <0 0x1001b000 0 0x1000>;
+			#clock-cells = <1>;
+		};
+
+		clock-controller@1001e000 {
+			compatible = "mediatek,mt7981-apmixedsys";
+			reg = <0 0x1001e000 0 0x1000>;
+			#clock-cells = <1>;
+		};
+
+		pwm@10048000 {
+			compatible = "mediatek,mt7981-pwm";
+			reg = <0 0x10048000 0 0x1000>;
+			clocks = <&infracfg CLK_INFRA_PWM_STA>,
+				<&infracfg CLK_INFRA_PWM_HCK>,
+				<&infracfg CLK_INFRA_PWM1_CK>,
+				<&infracfg CLK_INFRA_PWM2_CK>,
+				<&infracfg CLK_INFRA_PWM3_CK>;
+			clock-names = "top", "main", "pwm1", "pwm2", "pwm3";
+			#pwm-cells = <2>;
+		};
+
+		clock-controller@15000000 {
+			compatible = "mediatek,mt7981-ethsys", "syscon";
+			reg = <0 0x15000000 0 0x1000>;
+			#clock-cells = <1>;
+			#reset-cells = <1>;
+		};
+	};
+
+	timer {
+		compatible = "arm,armv8-timer";
+		interrupt-parent = <&gic>;
+		interrupts = <GIC_PPI 13 IRQ_TYPE_LEVEL_LOW>,
+			     <GIC_PPI 14 IRQ_TYPE_LEVEL_LOW>,
+			     <GIC_PPI 11 IRQ_TYPE_LEVEL_LOW>,
+			     <GIC_PPI 10 IRQ_TYPE_LEVEL_LOW>;
+	};
+};