mediatek: filogic: add support for Xiaomi AX3000T

Hardware specification:
  SoC: MediaTek MT7981B 2x A53
  Flash: ESMT F50L1G41LB 128MB
  RAM: NT52B128M16JR-FL 256MB
  Ethernet: 4x 10/100/1000 Mbps
  Switch: MediaTek MT7531AE
  WiFi: MediaTek MT7976C
  Button: Reset, Mesh
  Power: DC 12V 1A

Flash instructions:

1. Get ssh access

2. Backup import partitions
   ```
   dev:    size   erasesize  name
   mtd1: 00100000 00020000 "BL2"
   mtd2: 00040000 00020000 "Nvram"
   mtd3: 00040000 00020000 "Bdata"
   mtd4: 00200000 00020000 "Factory"
   mtd5: 00200000 00020000 "FIP"
   mtd8: 02200000 00020000 "ubi"
   mtd9: 02200000 00020000 "ubi1"
   mtd12: 00040000 00020000 "KF"

   ```

   Use these commands blow to backup your stock partitions.
   ```
   nanddump -f /tmp/BL2.bin /dev/mtd1
   nanddump -f /tmp/Nvram.bin /dev/mtd2
   nanddump -f /tmp/Bdata.bin /dev/mtd3
   nanddump -f /tmp/Factory.bin /dev/mtd4
   nanddump -f /tmp/FIP.bin /dev/mtd5
   nanddump -f /tmp/ubi.bin /dev/mtd8
   nanddump -f /tmp/KF.bin /dev/mtd12
   ```
   Then, transfer them to your computer via scp, netcat, tftp
   or others and keep them in a safe place.

3. Setup Nvram
   Get the current stock: `cat /proc/cmdline`

   If you find `firmware=0` or `mtd=ubi`, use these commands:
   ```
   nvram set boot_wait=on
   nvram set uart_en=1
   nvram set flag_boot_rootfs=1
   nvram set flag_last_success=1
   nvram set flag_boot_success=1
   nvram set flag_try_sys1_failed=0
   nvram set flag_try_sys2_failed=0
   nvram commit
   ```

   If you find `firmware=1` or `mtd=ubi1`, use these commands:
   ```
   nvram set boot_wait=on
   nvram set uart_en=1
   nvram set flag_boot_rootfs=0
   nvram set flag_last_success=0
   nvram set flag_boot_success=1
   nvram set flag_try_sys1_failed=0
   nvram set flag_try_sys2_failed=0
   nvram commit
   ```

4. Flash stock-initramfs-factory.ubi
   If you find `firmware=0` or `mtd=ubi`:
   `ubiformat /dev/mtd9 -y -f /tmp/stock-initramfs-factory.ubi`

   If you find `firmware=1` or `mtd=ubi1`:
   `ubiformat /dev/mtd8 -y -f /tmp/stock-initramfs-factory.ubi`

   Then reboot your router, it should boot to the openwrt
   initramfs system now.

5. Setup uboot-env
   Now it will be setup automatically in upgrade process,
   you can skip this step.

   If your `fw_setenv` did not work, you need run this command:
   `echo "/dev/mtd1 0x0 0x10000 0x20000" > /etc/fw_env.config`

   Then setup uboot-env:
   ```
   fw_setenv boot_wait on
   fw_setenv uart_en 1
   fw_setenv flag_boot_rootfs 0
   fw_setenv flag_last_success 1
   fw_setenv flag_boot_success 1
   fw_setenv flag_try_sys1_failed 8
   fw_setenv flag_try_sys2_failed 8
   fw_setenv mtdparts "nmbm0:1024k(bl2),256k(Nvram),256k(Bdata),
   2048k(factory),2048k(fip),256k(crash),256k(crash_log),
   34816k(ubi),34816k(ubi1),32768k(overlay),12288k(data),256k(KF)"
   ```

6. Flash stock-squashfs-sysupgrade.bin
   Use shell command:
   `sysupgrade -n /tmp/stock-squashfs-sysupgrade.bin`
   Or go to luci web.

If you need to change to Openwrt U-Boot layout, do next. If you
do not need, please ignore it.

Change to OpenWrt U-Boot:

1. Flash ubootmod-initramfs-factory.ubi
   Check mtd partitions: `cat /proc/mtd`
   ```
   mtd7: 00040000 00020000 "KF"
   mtd8: 02200000 00020000 "ubi_kernel"
   mtd9: 04e00000 00020000 "ubi"
   ```

   Run following command:
   `ubiformat /dev/mtd8 -y -f /tmp/ubootmod-initramfs-factory.ubi`
   Then reboot your router, it should boot to the openwrt initramfs
   system now.

2. Check mtd again
   ```
   mtd7: 00040000 00020000 "KF"
   mtd8: 07000000 00020000 "ubi"
   ```
   Make sure mtd8 is ubi.

3. Install kmod-mtd-rw
   Run command: `opkg update && opkg install kmod-mtd-rw`
   Or get it in openwrt server, or build it yourself, then install
   it manually

   Then run this command:
   `insmod /lib/modules/$(uname -r)/mtd-rw.ko i_want_a_brick=1`

4. Clean up pstore
   Run Command: `rm -f /sys/fs/pstore/*`

5. Format ubi and create new ubootenv volume
   ```
   ubidetach -p /dev/mtd8; ubiformat /dev/mtd8 -y; ubiattach -p /dev/mtd8
   ubimkvol /dev/ubi0 -n 0 -N ubootenv -s 128KiB
   ubimkvol /dev/ubi0 -n 1 -N ubootenv2 -s 128KiB
   ```

6. (Optional) Add recovery boot feature.
   ```
   ubimkvol /dev/ubi0 -n 2 -N recovery -s 10MiB
   ubiupdatevol /dev/ubi0_2 /tmp/ubootmod-initramfs-recovery.itb
   ```

7. Flash Openwrt U-Boot
   ```
   mtd write /tmp/ubootmod-preloader.bin BL2
   mtd write /tmp/ubootmod-bl31-uboot.fip FIP
   ```

6. Flash ubootmod-squashfs-sysupgrade.itb
   Use shell command:
   `sysupgrade -n /tmp/ubootmod-squashfs-sysupgrade.itb`
   Or go to luci web.

Now everything is done, Enjoy!

Go Back to stock from Openwrt U-Boot:

1. Force flash ubootmod-initramfs-recovery.itb
   Use shell command:
   `sysupgrade -F -n /tmp/ubootmod-initramfs-recovery.itb`
   Or go to luci web.
   Then it should boot to the openwrt initramfs system now.

2. Format ubi and Nvram
   ```
   ubidetach -p /dev/mtd8; ubiformat /dev/mtd8 -y; ubiattach -p /dev/mtd8
   mtd erase Nvram
   ```

3. Install kmod-mtd-rw
   Run command: `opkg update && opkg install kmod-mtd-rw`
   Or get it in openwrt server, or build it yourself, then install
   it manually

   Then run this command:
   `insmod /lib/modules/$(uname -r)/mtd-rw.ko i_want_a_brick=1`

4. Flash stock U-Boot and ubi
   ```
   mtd write /tmp/BL2.bin BL2
   mtd write /tmp/FIP.bin FIP
   mtd write /tmp/ubi.bin ubi
   ```
   Then reboot your router, waiting it finished rollback in minutes.

Go Back to stock from stock layout Openwrt:
   Just run command: `ubiformat /dev/mtd8 -y -f /tmp/ubi.bin`
   Then reboot your router, waiting it finished rollback in minutes.

target/linux/mediatek/dts/mt7981b-xiaomi-mi-router-ax3000t-stock.dts

@@ -0,0 +1,34 @@
+// SPDX-License-Identifier: GPL-2.0-or-later OR MIT
+
+/dts-v1/;
+#include "mt7981b-xiaomi-mi-router-ax3000t.dtsi"
+
+/ {
+	model = "Xiaomi Mi Router AX3000T (stock layout)";
+	compatible = "xiaomi,mi-router-ax3000t-stock", "mediatek,mt7981";
+};
+
+&spi_nand {
+	mediatek,nmbm;
+	mediatek,bmt-max-ratio = <1>;
+	mediatek,bmt-max-reserved-blocks = <64>;
+};
+
+&partitions {
+	// ubi_kernel is the ubi partition in stock.
+	partition@600000 {
+		label = "ubi_kernel";
+		reg = <0x600000 0x2200000>;
+	};
+
+	/* ubi is the result of squashing
+	 * consecutive stock partitions:
+	 * - ubi1
+	 * - overlay
+	 * - data
+	 */
+	partition@2800000 {
+		label = "ubi";
+		reg = <0x2800000 0x4e00000>;
+	};
+};

target/linux/mediatek/dts/mt7981b-xiaomi-mi-router-ax3000t-ubootmod.dts

@@ -0,0 +1,16 @@
+// SPDX-License-Identifier: GPL-2.0-or-later OR MIT
+
+/dts-v1/;
+#include "mt7981b-xiaomi-mi-router-ax3000t.dtsi"
+
+/ {
+	model = "Xiaomi Mi Router AX3000T (OpenWrt U-Boot layout)";
+	compatible = "xiaomi,mi-router-ax3000t-ubootmod", "mediatek,mt7981";
+};
+
+&partitions {
+	partition@600000 {
+		label = "ubi";
+		reg = <0x600000 0x7000000>;
+	};
+};

target/linux/mediatek/dts/mt7981b-xiaomi-mi-router-ax3000t.dtsi

@@ -0,0 +1,29 @@
+// SPDX-License-Identifier: GPL-2.0-or-later OR MIT
+
+/dts-v1/;
+#include "mt7981b-xiaomi-mi-router-common.dtsi"
+
+
+&gmac0 {
+	mac-address-increment = <(-2)>;
+};
+
+&i2c0 {
+	pinctrl-names = "default";
+	pinctrl-0 = <&i2c_pins>;
+	status = "okay";
+
+	nfc@57 {
+		compatible = "nt082c";
+		reg = <0x57>;
+	};
+};
+
+&pio {
+	i2c_pins: i2c-pins {
+		mux {
+			function = "i2c";
+			groups = "i2c0_1";
+		};
+	};
+};

target/linux/mediatek/dts/mt7981b-xiaomi-mi-router-common.dtsi

@@ -0,0 +1,238 @@
+// SPDX-License-Identifier: GPL-2.0-or-later OR MIT
+
+/dts-v1/;
+#include <dt-bindings/input/input.h>
+#include <dt-bindings/gpio/gpio.h>
+
+#include "mt7981.dtsi"
+
+/ {
+	aliases {
+		serial0 = &uart0;
+		led-boot = &led_system_yellow;
+		led-failsafe = &led_system_yellow;
+		led-running = &led_system_blue;
+		led-upgrade = &led_system_yellow;
+	};
+
+	chosen {
+		stdout-path = "serial0:115200n8";
+	};
+
+	memory {
+		reg = <0 0x40000000 0 0x10000000>;
+	};
+
+	gpio-keys {
+		compatible = "gpio-keys";
+
+		reset {
+			label = "reset";
+			gpios = <&pio 1 GPIO_ACTIVE_LOW>;
+			linux,code = <KEY_RESTART>;
+		};
+
+		mesh {
+			label = "mesh";
+			gpios = <&pio 0 GPIO_ACTIVE_LOW>;
+			linux,code = <BTN_9>;
+			linux,input-type = <EV_SW>;
+		};
+	};
+
+	leds: leds {
+		compatible = "gpio-leds";
+
+		led_system_blue: system_blue {
+			label = "blue:system";
+			gpios = <&pio 9 GPIO_ACTIVE_LOW>;
+		};
+
+		led_system_yellow: system_yellow {
+			label = "yellow:system";
+			gpios = <&pio 10 GPIO_ACTIVE_LOW>;
+		};
+	};
+};
+
+&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";
+
+		fixed-link {
+			speed = <2500>;
+			full-duplex;
+			pause;
+		};
+	};
+};
+
+&mdio_bus {
+	switch: switch@0 {
+		compatible = "mediatek,mt7531";
+		reg = <31>;
+		reset-gpios = <&pio 39 GPIO_ACTIVE_HIGH>;
+		interrupt-controller;
+		#interrupt-cells = <1>;
+		interrupt-parent = <&pio>;
+		interrupts = <38 IRQ_TYPE_LEVEL_HIGH>;
+	};
+};
+
+&switch {
+	ports {
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		port@0 {
+			reg = <0>;
+			label = "wan";
+		};
+
+		port@1 {
+			reg = <1>;
+			label = "lan2";
+		};
+
+		port@2 {
+			reg = <2>;
+			label = "lan3";
+		};
+
+		port@3 {
+			reg = <3>;
+			label = "lan4";
+		};
+
+		port@6 {
+			reg = <6>;
+			ethernet = <&gmac0>;
+			phy-mode = "2500base-x";
+
+			fixed-link {
+				speed = <2500>;
+				full-duplex;
+				pause;
+			};
+		};
+	};
+};
+
+&spi0 {
+	pinctrl-names = "default";
+	pinctrl-0 = <&spi0_flash_pins>;
+	status = "okay";
+
+	spi_nand: flash@0 {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		compatible = "spi-nand";
+		reg = <0>;
+
+		spi-max-frequency = <52000000>;
+		spi-tx-bus-width = <4>;
+		spi-rx-bus-width = <4>;
+
+		partitions: partitions {
+			compatible = "fixed-partitions";
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			partition@0 {
+				label = "BL2";
+				reg = <0x00 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;
+			};
+
+			partition@7600000 {
+				label = "KF";
+				reg = <0x7600000 0x40000>;
+				read-only;
+			};
+		};
+	};
+};
+
+&pio {
+	spi0_flash_pins: spi0-pins {
+		mux {
+			function = "spi";
+			groups = "spi0", "spi0_wp_hold";
+		};
+
+		conf-pu {
+			pins = "SPI0_CS", "SPI0_HOLD", "SPI0_WP";
+			drive-strength = <MTK_DRIVE_8mA>;
+			bias-pull-up = <MTK_PUPD_SET_R1R0_11>;
+		};
+
+		conf-pd {
+			pins = "SPI0_CLK", "SPI0_MOSI", "SPI0_MISO";
+			drive-strength = <MTK_DRIVE_8mA>;
+			bias-pull-down = <MTK_PUPD_SET_R1R0_11>;
+		};
+	};
+};
+
+&wifi {
+	status = "okay";
+
+	mediatek,mtd-eeprom = <&factory 0x0>;
+};
+
+&uart0 {
+	status = "okay";
+};
+
+&watchdog {
+	status = "okay";
+};