ramips: add support for Mercusys MR70X

Hardware
========
- SoC: MediaTek MT7621AT (880MHz, Duel-Core)
- RAM: DDR3 128MB
- Flash: Winbond W25Q128JV (SPI-NOR 16MB)
- WiFi: MediaTek MT7915D (2.4GHz, 5GHz, DBDC)
- Ethernet: MediaTek MT7530 (WAN x1, LAN x3, SoC)
- UART: >TX RX GND 3v3 (115200 8N1, J1)
        Do not connect 3v3. TX is marked with an arrow.

Installation
============
Flash factory image. This can be done using stock web ui.

Revert to stock firmware
========================
Flash stock firmware via OEM Web UI Recovery mode.

Web UI Recovery method
======================
1. Unplug the router
2. Plug in and hold reset button 5~10 secs
3. Set your computer IP address manually to 192.168.1.x / 255.255.255.0
4. Flash image with web browser to 192.168.1.1

Co-authored-by: Robert Senderek <robert.senderek@10g.pl>
Co-authored-by: Yoonji Park <koreapyj@dcmys.kr>
Signed-off-by: David Bauer <mail@david-bauer.net>

target/linux/ramips/dts/mt7621_mercusys_mr70x-v1.dts

@@ -0,0 +1,165 @@
+// SPDX-License-Identifier: GPL-2.0-or-later OR MIT
+
+#include "mt7621.dtsi"
+
+#include <dt-bindings/gpio/gpio.h>
+#include <dt-bindings/input/input.h>
+
+/ {
+	compatible = "mercusys,mr70x-v1", "mediatek,mt7621-soc";
+	model = "Mercusys MR70X v1";
+
+	aliases {
+		led-boot = &led_power_green;
+		led-failsafe = &led_power_orange;
+		led-running = &led_power_green;
+		led-upgrade = &led_power_orange;
+		label-mac-device = &gmac0;
+	};
+
+	chosen {
+		bootargs = "console=ttyS0,115200";
+	};
+
+	keys {
+		compatible = "gpio-keys";
+
+		reset {
+			label = "reset";
+			gpios = <&gpio 8 GPIO_ACTIVE_LOW>;
+			linux,code = <KEY_RESTART>;
+		};
+	};
+
+	leds {
+		compatible = "gpio-leds";
+
+		led_power_green: power-green {
+			label = "green:power";
+			gpios = <&gpio 4 GPIO_ACTIVE_LOW>;
+		};
+
+		led_power_orange: power-orange {
+			label = "orange:power";
+			gpios = <&gpio 3 GPIO_ACTIVE_LOW>;
+		};
+	};
+};
+
+&spi0 {
+	status = "okay";
+
+	flash@0 {
+		compatible = "jedec,spi-nor";
+		reg = <0>;
+		spi-max-frequency = <80000000>;
+
+		partitions {
+			compatible = "fixed-partitions";
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			partition@0 {
+				label = "u-boot";
+				reg = <0x000000 0x040000>;
+				read-only;
+			};
+
+			partition@40000 {
+				compatible = "denx,uimage";
+				label = "firmware";
+				reg = <0x040000 0xf60000>;
+			};
+
+			config: partition@fa0000 {
+				label = "config";
+				reg = <0xfa0000 0x010000>;
+				read-only;
+			};
+
+			partition@fb0000 {
+				label = "tplink";
+				reg = <0xfb0000 0x040000>;
+				read-only;
+			};
+
+			radio: partition@ff0000 {
+				label = "radio";
+				reg = <0xff0000 0x010000>;
+				read-only;
+			};
+		};
+	};
+};
+
+&pcie {
+	status = "okay";
+};
+
+&pcie1 {
+	wifi@0,0 {
+		compatible = "mediatek,mt76";
+		reg = <0x0000 0 0 0 0>;
+		mediatek,mtd-eeprom = <&radio 0x0>;
+		nvmem-cells = <&macaddr_config_8>;
+		nvmem-cell-names = "mac-address";
+		mediatek,disable-radar-background;
+	};
+};
+
+&gmac0 {
+	nvmem-cells = <&macaddr_config_8>;
+	nvmem-cell-names = "mac-address";
+};
+
+&gmac1 {
+	status = "okay";
+	label = "wan";
+	phy-handle = <&ethphy0>;
+
+	nvmem-cells = <&macaddr_config_8>;
+	nvmem-cell-names = "mac-address";
+	mac-address-increment = <1>;
+};
+
+&mdio {
+	ethphy0: ethernet-phy@0 {
+		reg = <0>;
+	};
+};
+
+&switch0 {
+	ports {
+		port@1 {
+			status = "okay";
+			label = "lan1";
+		};
+
+		port@2 {
+			status = "okay";
+			label = "lan2";
+		};
+
+		port@3 {
+			status = "okay";
+			label = "lan3";
+		};
+	};
+};
+
+&state_default {
+	gpio {
+		groups = "i2c", "uart3";
+		function = "gpio";
+	};
+};
+
+&config {
+	compatible = "nvmem-cells";
+	#address-cells = <1>;
+	#size-cells = <1>;
+
+	macaddr_config_8: macaddr@8 {
+		reg = <0x8 0x6>;
+	};
+};

target/linux/ramips/image/mt7621.mk

@@ -1496,6 +1496,19 @@ define Device/mediatek_mt7621-eval-board
 endef
 TARGET_DEVICES += mediatek_mt7621-eval-board
 
+define Device/mercusys_mr70x-v1
+  $(Device/dsa-migration)
+  $(Device/tplink-safeloader)
+  DEVICE_VENDOR := Mercusys
+  DEVICE_MODEL := MR70X
+  DEVICE_VARIANT := v1
+  DEVICE_PACKAGES := kmod-mt7915-firmware -uboot-envtools
+  TPLINK_BOARD_ID := MR70X
+  KERNEL := $(KERNEL_DTB) | uImage lzma
+  IMAGE_SIZE := 15744k
+endef
+TARGET_DEVICES += mercusys_mr70x-v1
+
 define Device/MikroTik
   $(Device/dsa-migration)
   DEVICE_VENDOR := MikroTik

target/linux/ramips/mt7621/base-files/etc/hotplug.d/ieee80211/10_fix_wifi_mac

@@ -120,6 +120,11 @@ case "$board" in
 		[ "$PHYNBR" = "0" ] && macaddr_add $hw_mac_addr 2 > /sys${DEVPATH}/macaddress
 		[ "$PHYNBR" = "1" ] && macaddr_add $hw_mac_addr 3 > /sys${DEVPATH}/macaddress
 		;;
+	mercusys,mr70x-v1|\
+	tplink,archer-ax23-v1)
+		hw_mac_addr="$(mtd_get_mac_binary config 0x8)"
+		[ "$PHYNBR" = "1" ] &&  macaddr_add "$hw_mac_addr" -1 > "/sys${DEVPATH}/macaddress"
+		;;
 	mts,wg430223)
 		hw_mac_addr=$(macaddr_add $(mtd_get_mac_encrypted_arcadyan "board_data") 1)
 		[ "$PHYNBR" = "0" ] && echo -n "$hw_mac_addr" > /sys${DEVPATH}/macaddress
@@ -147,10 +152,6 @@ case "$board" in
 		hw_mac_addr="$(mtd_get_mac_binary factory 0x4)"
 		[ "$PHYNBR" = "1" ] &&  macaddr_add $hw_mac_addr "0x100000" > /sys${DEVPATH}/macaddress
 		;;
-	tplink,archer-ax23-v1)
-		hw_mac_addr="$(mtd_get_mac_binary config 0x8)"
-		[ "$PHYNBR" = "1" ] &&  macaddr_add "$hw_mac_addr" -1 > "/sys${DEVPATH}/macaddress"
-		;;
 	tplink,eap615-wall-v1)
 		hw_mac_addr="$(mtd_get_mac_binary product-info 0x8)"
 		macaddr_add "$hw_mac_addr" "$PHYNBR" > "/sys${DEVPATH}/macaddress"