ramips: mt7621: add support for Xiaomi Mi Router 4A Gigabit v2

Device is the same as Xiaomi Mi Router 4A Gigabit, except of:
- 5G WiFi is MT7663
- addresses of leds, wifi and eth ports are slightly changed

Specs:
  SoC:  MT7621
  CPU:  2 x 880 MHz
  ROM:  16 MB
  RAM:  128 MB
  WLAN: MT7603, MT7663

MAC addresses:
  WAN     ****  factory 0xe006 (label)
  LAN     *:f7  factory 0xe000
  2.4 GHz *:f8  factory 0x0000+0x4 (mtd-eeprom+0x4)
  5 GHz   *:f9  factory 0x8000+0x4 (mtd-eeprom+0x4)

Installation:

Factory firmware is based on a custom OpenWrt 17.x.
Installation is the same as for Xiaomi Mi Router 4A Gigabit.

Probably the easiest way to install is to use the script from
this repository: https://github.com/acecilia/OpenWRTInvasion/pull/155

In a more advanced case, you can do everything yourself:
- gain access to the device through one of the exploits described
  in the link above
- upload sysupgrade image to /tmp
- overwrite stock firmware:
  # mtd -e OS1 -r write /tmp/sysupgrade.bin OS1

Recovery:

Recovery procedure is the same as for Xiaomi Mi Router 4A Gigabit.
Possible options can be found here:
https://openwrt.org/inbox/toh/xiaomi/xiaomi_mi_router_4a_gigabit_edition

One of the ways is to use another router with OpenWrt:
- connect both routers by their LAN ports
- download stock firmware from [1]
- place it inside /tmp/test.bin on the main router
- configure PXE/TFTP on the main router
- power off 4Av2, hold Reset button, power on
- as soon as image download via TFTP starts, Reset can be released
- blinking blue wan LED will indicate the end of the flashing process,
  now router can be rebooted
[1] http://cdn.cnbj1.fds.api.mi-img.com/xiaoqiang/rom/r4av2/miwifi_r4av2_firmware_release_2.30.28.bin

Signed-off-by: Dmitry Sokolov <e323w@proton.me>

3 files changed, 225 insertions, 131 deletions

diff --git a/target/linux/ramips/dts/mt7621_xiaomi_mi-router-4a-3g-v2.dtsi b/target/linux/ramips/dts/mt7621_xiaomi_mi-router-4a-3g-v2.dtsi
index a0ee79ae23..d05872337b 100644
--- a/target/linux/ramips/dts/mt7621_xiaomi_mi-router-4a-3g-v2.dtsi
+++ b/target/linux/ramips/dts/mt7621_xiaomi_mi-router-4a-3g-v2.dtsi
@@ -1,23 +1,12 @@
 // 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>
+#include "mt7621_xiaomi_mi-router-4a-common.dtsi"
 
 / {
 	aliases {
-		led-boot = &led_status_yellow;
-		led-failsafe = &led_status_yellow;
-		led-running = &led_status_blue;
-		led-upgrade = &led_status_yellow;
 		label-mac-device = &gmac1;
 	};
 
-	chosen {
-		bootargs = "console=ttyS0,115200n8";
-	};
-
 	leds {
 		compatible = "gpio-leds";
 
@@ -31,108 +20,16 @@
 			gpios = <&gpio 10 GPIO_ACTIVE_LOW>;
 		};
 	};
-
-	keys {
-		compatible = "gpio-keys";
-
-		reset {
-			label = "reset";
-			gpios = <&gpio 18 GPIO_ACTIVE_LOW>;
-			linux,code = <KEY_RESTART>;
-		};
-	};
 };
 
-&spi0 {
-	status = "okay";
-
-	flash@0 {
-		compatible = "jedec,spi-nor";
-		reg = <0>;
-		spi-max-frequency = <50000000>;
-		m25p,fast-read;
-
-		partitions {
-			compatible = "fixed-partitions";
-			#address-cells = <1>;
-			#size-cells = <1>;
-
-			partition@0 {
-				label = "u-boot";
-				reg = <0x0 0x30000>;
-				read-only;
-			};
-
-			partition@30000 {
-				label = "u-boot-env";
-				reg = <0x30000 0x10000>;
-				read-only;
-			};
-
-			partition@40000 {
-				label = "Bdata";
-				reg = <0x40000 0x10000>;
-				read-only;
-			};
-
-			factory: partition@50000 {
-				label = "factory";
-				reg = <0x50000 0x10000>;
-				read-only;
-			};
-
-			partition@60000 {
-				label = "crash";
-				reg = <0x60000 0x10000>;
-				read-only;
-			};
-
-			partition@70000 {
-				label = "cfg_bak";
-				reg = <0x70000 0x10000>;
-				read-only;
-			};
-
-			partition@80000 {
-				label = "overlay";
-				reg = <0x80000 0x100000>;
-				read-only;
-			};
-
-			firmware: partition@180000 {
-				compatible = "denx,uimage";
-				label = "firmware";
-				reg = <0x180000 0xe80000>;
-			};
-		};
-	};
+&wifi0 {
+	mediatek,mtd-eeprom = <&factory 0x8000>;
+	ieee80211-freq-limit = <5000000 6000000>;
 };
 
-&pcie {
-	status = "okay";
-};
-
-&pcie0 {
-	wifi@0,0 {
-		compatible = "pci14c3,7662";
-		reg = <0x0000 0 0 0 0>;
-		mediatek,mtd-eeprom = <&factory 0x8000>;
-		ieee80211-freq-limit = <5000000 6000000>;
-	};
-};
-
-&pcie1 {
-	wifi@0,0 {
-		compatible = "pci14c3,7603";
-		reg = <0x0000 0 0 0 0>;
-		mediatek,mtd-eeprom = <&factory 0x0000>;
-		ieee80211-freq-limit = <2400000 2500000>;
-	};
-};
-
-&gmac0 {
-	nvmem-cells = <&macaddr_factory_e000>;
-	nvmem-cell-names = "mac-address";
+&wifi1 {
+	mediatek,mtd-eeprom = <&factory 0x0000>;
+	ieee80211-freq-limit = <2400000 2500000>;
 };
 
 &gmac1 {
@@ -163,24 +60,3 @@
 		};
 	};
 };
-
-&state_default {
-	gpio {
-		groups = "jtag", "uart2", "uart3", "wdt";
-		function = "gpio";
-	};
-};
-
-&factory {
-	compatible = "nvmem-cells";
-	#address-cells = <1>;
-	#size-cells = <1>;
-
-	macaddr_factory_e000: macaddr@e000 {
-		reg = <0xe000 0x6>;
-	};
-
-	macaddr_factory_e006: macaddr@e006 {
-		reg = <0xe006 0x6>;
-	};
-};
diff --git a/target/linux/ramips/dts/mt7621_xiaomi_mi-router-4a-common.dtsi b/target/linux/ramips/dts/mt7621_xiaomi_mi-router-4a-common.dtsi
new file mode 100644
index 0000000000..efc32733e9
--- /dev/null
+++ b/target/linux/ramips/dts/mt7621_xiaomi_mi-router-4a-common.dtsi
@@ -0,0 +1,138 @@
+// 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>
+
+/ {
+	aliases {
+		led-boot = &led_status_yellow;
+		led-failsafe = &led_status_yellow;
+		led-running = &led_status_blue;
+		led-upgrade = &led_status_yellow;
+	};
+
+	chosen {
+		bootargs = "console=ttyS0,115200n8";
+	};
+
+	keys {
+		compatible = "gpio-keys";
+
+		reset {
+			label = "reset";
+			gpios = <&gpio 18 GPIO_ACTIVE_LOW>;
+			linux,code = <KEY_RESTART>;
+		};
+	};
+};
+
+&spi0 {
+	status = "okay";
+
+	flash@0 {
+		compatible = "jedec,spi-nor";
+		reg = <0>;
+		spi-max-frequency = <50000000>;
+		m25p,fast-read;
+
+		partitions: partitions {
+			compatible = "fixed-partitions";
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			partition@0 {
+				label = "u-boot";
+				reg = <0x0 0x30000>;
+				read-only;
+			};
+
+			partition@30000 {
+				label = "u-boot-env";
+				reg = <0x30000 0x10000>;
+				read-only;
+			};
+
+			partition@40000 {
+				label = "Bdata";
+				reg = <0x40000 0x10000>;
+				read-only;
+			};
+
+			factory: partition@50000 {
+				label = "factory";
+				reg = <0x50000 0x10000>;
+				read-only;
+			};
+
+			partition@60000 {
+				label = "crash";
+				reg = <0x60000 0x10000>;
+				read-only;
+			};
+
+			partition@70000 {
+				label = "cfg_bak";
+				reg = <0x70000 0x10000>;
+				read-only;
+			};
+
+			partition@80000 {
+				label = "overlay";
+				reg = <0x80000 0x100000>;
+				read-only;
+			};
+
+			firmware: partition@180000 {
+				compatible = "denx,uimage";
+				label = "firmware";
+				reg = <0x180000 0xe80000>;
+			};
+		};
+	};
+};
+
+&pcie {
+	status = "okay";
+};
+
+&pcie0 {
+	wifi0: wifi@0,0 {
+		compatible = "mediatek,mt76";
+		reg = <0x0000 0 0 0 0>;
+	};
+};
+
+&pcie1 {
+	wifi1: wifi@0,0 {
+		compatible = "mediatek,mt76";
+		reg = <0x0000 0 0 0 0>;
+	};
+};
+
+&gmac0 {
+	nvmem-cells = <&macaddr_factory_e000>;
+	nvmem-cell-names = "mac-address";
+};
+
+&state_default {
+	gpio {
+		groups = "jtag", "uart2", "uart3", "wdt";
+		function = "gpio";
+	};
+};
+
+&factory {
+	compatible = "nvmem-cells";
+	#address-cells = <1>;
+	#size-cells = <1>;
+
+	macaddr_factory_e000: macaddr@e000 {
+		reg = <0xe000 0x6>;
+	};
+
+	macaddr_factory_e006: macaddr@e006 {
+		reg = <0xe006 0x6>;
+	};
+};
diff --git a/target/linux/ramips/dts/mt7621_xiaomi_mi-router-4a-gigabit-v2.dts b/target/linux/ramips/dts/mt7621_xiaomi_mi-router-4a-gigabit-v2.dts
new file mode 100644
index 0000000000..67ff6ea11e
--- /dev/null
+++ b/target/linux/ramips/dts/mt7621_xiaomi_mi-router-4a-gigabit-v2.dts
@@ -0,0 +1,80 @@
+// SPDX-License-Identifier: GPL-2.0-or-later OR MIT
+
+#include "mt7621_xiaomi_mi-router-4a-common.dtsi"
+
+/ {
+	compatible = "xiaomi,mi-router-4a-gigabit-v2", "mediatek,mt7621-soc";
+	model = "Xiaomi Mi Router 4A Gigabit Edition v2";
+
+	aliases {
+		label-mac-device = &wan;
+	};
+
+	leds {
+		compatible = "gpio-leds";
+
+		led_status_blue: status_blue {
+			label = "blue:status";
+			gpios = <&gpio 13 GPIO_ACTIVE_LOW>;
+		};
+
+		led_status_yellow: status_yellow {
+			label = "yellow:status";
+			gpios = <&gpio 15 GPIO_ACTIVE_LOW>;
+		};
+
+		wan_blue {
+			label = "blue:wan";
+			gpios = <&gpio 14 GPIO_ACTIVE_LOW>;
+		};
+
+		wan_yellow {
+			label = "yellow:wan";
+			gpios = <&gpio 16 GPIO_ACTIVE_LOW>;
+		};
+	};
+};
+
+&partitions {
+	partition@180000 {
+		// size changed against to the common dtsi
+		reg = <0x180000 0xe70000>;
+	};
+
+	partition@ff0000 {
+		label = "Config";
+		reg = <0xff0000 0x10000>;
+		read-only;
+	};
+};
+
+&wifi0 {
+	mediatek,mtd-eeprom = <&factory 0x0000>;
+	ieee80211-freq-limit = <2400000 2500000>;
+};
+
+&wifi1 {
+	mediatek,mtd-eeprom = <&factory 0x8000>;
+	ieee80211-freq-limit = <5000000 6000000>;
+};
+
+&switch0 {
+	ports {
+		port@1 {
+			status = "okay";
+			label = "lan1";
+		};
+
+		port@2 {
+			status = "okay";
+			label = "lan2";
+		};
+
+		wan: port@3 {
+			status = "okay";
+			label = "wan";
+			nvmem-cells = <&macaddr_factory_e006>;
+			nvmem-cell-names = "mac-address";
+		};
+	};
+};