ramips: add support for Cudy R700

This is the same hardware as the Cudy WR2100 that's
had support for some time now, just without the WLAN
hardware.

This PR is mostly copied from the commit that added
support for the WR2100, here: 3501db9

Specifications:
SoC: MT7621
CPU: 880 MHz
Flash: 16 MiB
RAM: 128 MiB
Ethernet: 5x Gbit ports

Installation:
There are two known options:

The Luci-based UI.
Press and hold the reset button during power up.
The router will request 'recovery.bin' from a TFTP server at
192.168.1.88.

Both options require a signed firmware binary.
A signed firmware can be found in GitHub PR #18532.

R4 & R5 need to be shorted (0-100Ω) for the UART to work.

Link: https://github.com/openwrt/openwrt/pull/18532

Signed-off-by: David DeGraw <degraw@fastmail.com>

target/linux/ramips/dts/mt7621_cudy_r700.dts

@@ -0,0 +1,203 @@
+// 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 <dt-bindings/leds/common.h>
+
+/ {
+	compatible = "cudy,r700", "mediatek,mt7621-soc";
+	model = "Cudy R700";
+
+	aliases {
+		led-boot = &led_internet_blue;
+		led-failsafe = &led_internet_blue;
+		led-running = &led_internet_blue;
+		led-upgrade = &led_internet_blue;
+		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_internet_blue: internet_blue {
+			label = "blue:internet";
+			gpios = <&gpio 4 GPIO_ACTIVE_LOW>;
+		};
+
+		internet_red {
+			label = "red:internet";
+			gpios = <&gpio 3 GPIO_ACTIVE_LOW>;
+		};
+
+		wan {
+			function = LED_FUNCTION_WAN;
+			color = <LED_COLOR_ID_GREEN>;
+			gpios = <&gpio 13 GPIO_ACTIVE_LOW>;
+		};
+
+		lan1 {
+			label = "green:lan1";
+			gpios = <&gpio 14 GPIO_ACTIVE_LOW>;
+		};
+
+		lan2 {
+			label = "green:lan2";
+			gpios = <&gpio 18 GPIO_ACTIVE_LOW>;
+		};
+
+		lan3 {
+			label = "green:lan3";
+			gpios = <&gpio 16 GPIO_ACTIVE_LOW>;
+		};
+
+		lan4 {
+			label = "green:lan4";
+			gpios = <&gpio 15 GPIO_ACTIVE_LOW>;
+		};
+	};
+};
+
+&gmac0 {
+	nvmem-cells = <&macaddr_bdinfo_de00 0>;
+	nvmem-cell-names = "mac-address";
+};
+
+&spi0 {
+	status = "okay";
+
+	flash@0 {
+		compatible = "jedec,spi-nor";
+		reg = <0>;
+		spi-max-frequency = <50000000>;
+
+		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 = "factory";
+				reg = <0x40000 0x10000>;
+				read-only;
+
+				nvmem-layout {
+					compatible = "fixed-layout";
+					#address-cells = <1>;
+					#size-cells = <1>;
+
+					eeprom_factory_0: eeprom@0 {
+						reg = <0x0 0x400>;
+					};
+
+					eeprom_factory_8000: eeprom@8000 {
+						reg = <0x8000 0x4da8>;
+					};
+				};
+			};
+
+			partition@50000 {
+				compatible = "denx,uimage";
+				label = "firmware";
+				reg = <0x50000 0xf80000>;
+			};
+
+			partition@fd0000 {
+				label = "debug";
+				reg = <0xfd0000 0x10000>;
+				read-only;
+			};
+
+			partition@fe0000 {
+				label = "backup";
+				reg = <0xfe0000 0x10000>;
+				read-only;
+			};
+
+			partition@ff0000 {
+				label = "bdinfo";
+				reg = <0xff0000 0x10000>;
+				read-only;
+
+				nvmem-layout {
+					compatible = "fixed-layout";
+					#address-cells = <1>;
+					#size-cells = <1>;
+
+					macaddr_bdinfo_de00: macaddr@de00 {
+						compatible = "mac-base";
+						reg = <0xde00 0x6>;
+						#nvmem-cell-cells = <1>;
+					};
+				};
+			};
+		};
+	};
+};
+
+&state_default {
+	gpio {
+		groups = "i2c", "jtag", "uart3", "wdt";
+		function = "gpio";
+	};
+};
+
+&gmac1 {
+	status = "okay";
+	label = "wan";
+	phy-handle = <&ethphy4>;
+
+	nvmem-cells = <&macaddr_bdinfo_de00 1>;
+	nvmem-cell-names = "mac-address";
+};
+
+&switch0 {
+	ports {
+		port@0 {
+			status = "okay";
+			label = "lan1";
+		};
+
+		port@1 {
+			status = "okay";
+			label = "lan2";
+		};
+
+		port@2 {
+			status = "okay";
+			label = "lan3";
+		};
+
+		port@3 {
+			status = "okay";
+			label = "lan4";
+		};
+	};
+};

target/linux/ramips/image/mt7621.mk

@@ -768,6 +768,16 @@ define Device/cudy_wr2100
 endef
 TARGET_DEVICES += cudy_wr2100
 
+define Device/cudy_r700
+  $(Device/dsa-migration)
+  DEVICE_VENDOR := Cudy
+  DEVICE_MODEL := R700
+  IMAGE_SIZE := 15872k
+  UIMAGE_NAME := R29
+  DEVICE_PACKAGES := -uboot-envtools
+endef
+TARGET_DEVICES += cudy_r700
+
 define Device/cudy_x6-v1
   $(Device/dsa-migration)
   IMAGE_SIZE := 32256k

target/linux/ramips/mt7621/base-files/etc/board.d/01_leds

@@ -63,6 +63,7 @@ genexis,pulse-ex400|\
 netis,n6)
 	ucidef_set_led_netdev "wan" "wan" "green:wan" "wan" "link tx rx"
 	;;
+cudy,r700|\
 cudy,wr2100)
 	ucidef_set_led_netdev "lan1" "lan1" "green:lan1" "lan1"
 	ucidef_set_led_netdev "lan2" "lan2" "green:lan2" "lan2"