mediatek: add Xiaomi Redmi Router AX6000 support

Hardware specification:
  SoC: MediaTek MT7986A 4x A53
  Flash: ESMT F50L1G41LB 128 MB
  RAM: K4A4G165WF-BCWE 512 MB
  Ethernet: 4x 10/100/1000 Mbps
  WiFi1: MT7976GN 2.4GHz ax 4x4
  WiFi2: MT7976AN 5GHz ax 4x4
  Button: Mesh, Reset

Flash instructions:
  1. Gain ssh and serial port access, see the link below:
     https://openwrt.org/toh/xiaomi/redmi_ax6000#installation
  2. Use ssh or serial port to log in to the router, and
     execute the following command:
     nvram set boot_wait=on
     nvram set flag_boot_rootfs=0
     nvram set flag_boot_success=1
     nvram set flag_last_success=1
     nvram set flag_try_sys1_failed=8
     nvram set flag_try_sys2_failed=8
     nvram commit
  3. Set a static ip on the ethernet interface of your computer
     (e.g. default: ip 192.168.31.100, gateway 192.168.31.1)
  4. Download the initramfs image, rename it to initramfs.bin,
     and host it with the tftp server.
  5. Interrupt U-Boot and run these commands:
     setenv mtdparts nmbm0:1024k(bl2),256k(Nvram),256k(Bdata),2048k(factory),2048k(fip),256k(crash),256k(crash_log),112640k(ubi)
     saveenv
     tftpboot initramfs.bin
     bootm
  6. After openwrt boots up, use scp or luci web
     to upload sysupgrade.bin to upgrade.

Revert to stock firmware:
  Restore mtdparts back to default, then use the
  vendor's recovery tool (Windows only).

Signed-off-by: Chukun Pan <amadeus@jmu.edu.cn>

1 files changed, 255 insertions, 0 deletions

diff --git a/target/linux/mediatek/dts/mt7986a-xiaomi-redmi-router-ax6000.dts b/target/linux/mediatek/dts/mt7986a-xiaomi-redmi-router-ax6000.dts
new file mode 100644
index 0000000000..7c590d22e2
--- /dev/null
+++ b/target/linux/mediatek/dts/mt7986a-xiaomi-redmi-router-ax6000.dts
@@ -0,0 +1,255 @@
+// SPDX-License-Identifier: (GPL-2.0 OR MIT)
+
+/dts-v1/;
+#include <dt-bindings/input/input.h>
+#include <dt-bindings/gpio/gpio.h>
+
+#include "mt7986a.dtsi"
+
+/ {
+	model = "Xiaomi Redmi Router AX6000";
+	compatible = "xiaomi,redmi-router-ax6000", "mediatek,mt7986a";
+
+	aliases {
+		serial0 = &uart0;
+	};
+
+	chosen {
+		stdout-path = "serial0:115200n8";
+	};
+
+	memory {
+		reg = <0 0x40000000 0 0x20000000>;
+	};
+
+	keys {
+		compatible = "gpio-keys";
+
+		reset {
+			label = "reset";
+			gpios = <&pio 9 GPIO_ACTIVE_LOW>;
+			linux,code = <KEY_RESTART>;
+		};
+
+		mesh {
+			label = "mesh";
+			gpios = <&pio 10 GPIO_ACTIVE_LOW>;
+			linux,code = <BTN_9>;
+			linux,input-type = <EV_SW>;
+		};
+	};
+};
+
+&eth {
+	status = "okay";
+
+	gmac0: mac@0 {
+		compatible = "mediatek,eth-mac";
+		reg = <0>;
+		phy-mode = "2500base-x";
+
+		nvmem-cells = <&macaddr_factory_4>;
+		nvmem-cell-names = "mac-address";
+		mac-address-increment = <(-1)>;
+
+		fixed-link {
+			speed = <2500>;
+			full-duplex;
+			pause;
+		};
+	};
+
+	mdio: mdio-bus {
+		#address-cells = <1>;
+		#size-cells = <0>;
+	};
+};
+
+&mdio {
+	switch: switch@0 {
+		compatible = "mediatek,mt7531";
+		reg = <31>;
+		reset-gpios = <&pio 5 GPIO_ACTIVE_HIGH>;
+		interrupt-controller;
+		#interrupt-cells = <1>;
+		interrupt-parent = <&pio>;
+		interrupts = <66 IRQ_TYPE_LEVEL_HIGH>;
+	};
+};
+
+&pio {
+	spi_flash_pins: spi-flash-pins-33-to-38 {
+		mux {
+			function = "spi";
+			groups = "spi0", "spi0_wp_hold";
+		};
+		conf-pu {
+			pins = "SPI2_CS", "SPI2_HOLD", "SPI2_WP";
+			drive-strength = <8>;
+			mediatek,pull-up-adv = <0>; /* bias-disable */
+		};
+		conf-pd {
+			pins = "SPI2_CLK", "SPI2_MOSI", "SPI2_MISO";
+			drive-strength = <8>;
+			mediatek,pull-down-adv = <0>; /* bias-disable */
+		};
+	};
+
+	wf_2g_5g_pins: wf_2g_5g-pins {
+		mux {
+			function = "wifi";
+			groups = "wf_2g", "wf_5g";
+		};
+		conf {
+			pins = "WF0_HB1", "WF0_HB2", "WF0_HB3", "WF0_HB4",
+			       "WF0_HB0", "WF0_HB0_B", "WF0_HB5", "WF0_HB6",
+			       "WF0_HB7", "WF0_HB8", "WF0_HB9", "WF0_HB10",
+			       "WF0_TOP_CLK", "WF0_TOP_DATA", "WF1_HB1",
+			       "WF1_HB2", "WF1_HB3", "WF1_HB4", "WF1_HB0",
+			       "WF1_HB5", "WF1_HB6", "WF1_HB7", "WF1_HB8",
+			       "WF1_TOP_CLK", "WF1_TOP_DATA";
+			drive-strength = <4>;
+		};
+	};
+};
+
+&spi0 {
+	pinctrl-names = "default";
+	pinctrl-0 = <&spi_flash_pins>;
+	cs-gpios = <0>, <0>;
+	status = "okay";
+
+	flash@0 {
+		compatible = "spi-nand";
+		#address-cells = <1>;
+		#size-cells = <1>;
+		reg = <0>;
+
+		mediatek,nmbm;
+		mediatek,bmt-max-ratio = <1>;
+		mediatek,bmt-max-reserved-blocks = <64>;
+
+		spi-max-frequency = <20000000>;
+		spi-tx-buswidth = <4>;
+		spi-rx-buswidth = <4>;
+
+		partitions {
+			compatible = "fixed-partitions";
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			partition@0 {
+				label = "BL2";
+				reg = <0x0 0x100000>;
+				read-only;
+			};
+
+			partition@100000 {
+				label = "Nvram";
+				reg = <0x100000 0x40000>;
+			};
+
+			partition@140000 {
+				label = "Bdata";
+				reg = <0x140000 0x40000>;
+			};
+
+			factory: partition@180000 {
+				label = "Factory";
+				reg = <0x180000 0x200000>;
+				read-only;
+
+				compatible = "nvmem-cells";
+				#address-cells = <1>;
+				#size-cells = <1>;
+
+				macaddr_factory_4: macaddr@4 {
+					reg = <0x4 0x6>;
+				};
+			};
+
+			partition@380000 {
+				label = "FIP";
+				reg = <0x380000 0x200000>;
+				read-only;
+			};
+
+			partition@580000 {
+				label = "crash";
+				reg = <0x580000 0x40000>;
+				read-only;
+			};
+
+			partition@5c0000 {
+				label = "crash_log";
+				reg = <0x5c0000 0x40000>;
+				read-only;
+			};
+
+			/* ubi partition is the result of squashing
+			 * consecutive stock partitions:
+			 * - ubi
+			 * - ubi1
+			 * - overlay
+			 */
+			partition@600000 {
+				label = "ubi";
+				reg = <0x600000 0x6e00000>;
+			};
+
+			/* last 12 MiB is reserved for NMBM bad block table */
+		};
+	};
+};
+
+&switch {
+	ports {
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		port@1 {
+			reg = <1>;
+			label = "lan4";
+		};
+
+		port@2 {
+			reg = <2>;
+			label = "lan3";
+		};
+
+		port@3 {
+			reg = <3>;
+			label = "lan2";
+		};
+
+		port@4 {
+			reg = <4>;
+			label = "wan";
+		};
+
+		port@6 {
+			reg = <6>;
+			label = "cpu";
+			ethernet = <&gmac0>;
+			phy-mode = "2500base-x";
+
+			fixed-link {
+				speed = <2500>;
+				full-duplex;
+				pause;
+			};
+		};
+	};
+};
+
+&wmac {
+	status = "okay";
+	pinctrl-names = "default";
+	pinctrl-0 = <&wf_2g_5g_pins>;
+
+	mediatek,mtd-eeprom = <&factory 0x0>;
+};
+
+&uart0 {
+	status = "okay";
+};