ramips: add support for SNR-CPE-W4N-MT router

General specification:
- SoC Type: MediaTek MT7620N (580MHz)
- ROM: 8 MB SPI-NOR (W25Q64FV)
- RAM: 64 MB DDR (M13S5121632A)
- Switch: MediaTek MT7530
- Ethernet: 5 ports - 5×100MbE (WAN, LAN1-4)
- Wireless 2.4 GHz: b/g/n
- Buttons: 1 button (RESET)
- Bootloader: U-Boot 1.1.3, MediaTek U-Boot: 5.0.0.5
- Power: 12 VDC, 1.0 A

Flash by the native uploader in 2 stages:
1. Use the native uploader to flash an initramfs image. Choose
 openwrt-ramips-mt7620-snr_cpe-w4n-mt-initramfs-kernel.bin file by
 "Administration/Management/Firmware update/Choose File" in vendor's
 web interface (ip: 192.168.1.10, login: Admin, password: Admin).
 Wait ~160 seconds.
2. Flash a sysupgrade image via the initramfs image. Choose
 openwrt-ramips-mt7620-snr_cpe-w4n-mt-squashfs-sysupgrade.bin
 file by "System/Backup/Flash Firmware/Flash image..." in
 LuCI web interface (ip: 192.168.1.1, login: root, no password).
 Wait ~240 seconds.

Flash by U-Boot TFTP method:
1. Configure your PC with IP 192.168.1.131
2. Set up TFTP server and put the
 openwrt-ramips-mt7620-snr_cpe-w4n-mt-squashfs-sysupgrade.bin
 image on your PC
3. Connect serial port (57600 8N1) and turn on the router.
 Then interrupt "U-Boot Boot Menu" by hitting 2 key (select "2:
 Load system code then write to Flash via TFTP.").
Press Y key when show "Warning!! Erase Linux in Flash then burn
 new one. Are you sure? (Y/N)"
Input device IP (192.168.1.1) ==:192.168.1.1
Input server IP (192.168.1.131) ==:192.168.1.131
Input Linux Kernel filename () ==:
openwrt-ramips-mt7620-snr_cpe-w4n-mt-squashfs-sysupgrade.bin
3. Wait ~120 seconds to complete flashing

Signed-off-by: Alexey Bartenev <41exey@proton.me>

1 files changed, 122 insertions, 0 deletions

diff --git a/target/linux/ramips/dts/mt7620n_snr_cpe-w4n-mt.dts b/target/linux/ramips/dts/mt7620n_snr_cpe-w4n-mt.dts
new file mode 100644
index 0000000000..97e6043642
--- /dev/null
+++ b/target/linux/ramips/dts/mt7620n_snr_cpe-w4n-mt.dts
@@ -0,0 +1,122 @@
+// SPDX-License-Identifier: GPL-2.0-or-later OR MIT
+
+#include "mt7620n.dtsi"
+
+#include <dt-bindings/gpio/gpio.h>
+#include <dt-bindings/input/input.h>
+#include <dt-bindings/leds/common.h>
+
+/ {
+	compatible = "snr,cpe-w4n-mt", "ralink,mt7620n-soc";
+	model = "SNR-CPE-W4N (rev.M)";
+
+	aliases {
+		led-boot = &led_wps;
+		led-failsafe = &led_sys;
+		led-running = &led_wps;
+		led-upgrade = &led_sys;
+	};
+
+	leds {
+		compatible = "gpio-leds";
+
+		led_sys: sys {
+			label = "green:sys";
+			color = <LED_COLOR_ID_GREEN>;
+			function = LED_FUNCTION_STATUS;
+			gpios = <&gpio1 14 GPIO_ACTIVE_LOW>; // GPIO#38
+			panic-indicator;
+		};
+
+		led_wps: wps {
+			label = "green:wps";
+			color = <LED_COLOR_ID_GREEN>;
+			function = LED_FUNCTION_WPS;
+			gpios = <&gpio1 15 GPIO_ACTIVE_HIGH>; // GPIO#39
+		};
+
+		wlan {
+			label = "green:wlan";
+			color = <LED_COLOR_ID_GREEN>;
+			function = LED_FUNCTION_WLAN;
+			gpios = <&gpio3 0 GPIO_ACTIVE_LOW>; // GPIO#72
+		};
+	};
+
+	keys {
+		compatible = "gpio-keys";
+
+		reset {
+			label = "Reset Button";
+			gpios = <&gpio0 1 GPIO_ACTIVE_HIGH>; // GPIO#1
+			linux,code = <KEY_RESTART>;
+		};
+	};
+};
+
+&gpio0 {
+	status = "okay";
+};
+
+&gpio1 {
+	status = "okay";
+};
+
+&gpio3 {
+	status = "okay";
+};
+
+&spi0 {
+	status = "okay";
+
+	flash@0 {
+		compatible = "jedec,spi-nor";
+		reg = <0>;
+		spi-max-frequency = <48000000>;
+
+		partitions {
+			compatible = "fixed-partitions";
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			partition@0 {
+				label = "Bootloader";
+				reg = <0x0 0x30000>;
+				read-only;
+			};
+
+			partition@30000 {
+				label = "Config";
+				reg = <0x30000 0x10000>;
+			};
+
+			factory: partition@40000 {
+				label = "Factory";
+				reg = <0x40000 0x100000>;
+				read-only;
+			};
+
+			partition@50000 {
+				compatible = "denx,uimage";
+				label = "firmware";
+				reg = <0x50000 0x7b0000>;
+			};
+
+			partition@30000_1 {
+				label = "uboot-env";
+				reg = <0x30000 0x1000>;
+			};
+		};
+	};
+};
+
+&state_default {
+	gpio {
+		groups = "i2c", "spi refclk";
+		function = "gpio";
+	};
+};
+
+&wmac {
+	ralink,mtd-eeprom = <&factory 0x0>;
+};