ramips: add support for Belkin RT1800

Belkin RT1800 is an 802.11ax (Wi-Fi 6) router, based on MediaTek
MT7621A.

Specifications:
- SoC: MT7621 (880MHz, 2 Cores)
- RAM: 256 MB
- Flash: 128 MB NAND
- Wi-Fi:
  - MT7915D: 2.4/5 GHz (DBDC)
- Ethernet: 5x 1GiE MT7530
- USB: 1x USB 3.0
- UART: J4 (57600 baud)
  - Pinout: [3V3] (TXD) (RXD) (blank) (GND)

Notes:
* This device has a dual-boot partition scheme, but this firmware works
  only on boot partition 1.

Installation:

Upload the generated factory.bin image via the stock web firmware
updater.

Signed-off-by: Rosen Penev <rosenp@gmail.com>

1 files changed, 165 insertions, 0 deletions

diff --git a/target/linux/ramips/dts/mt7621_belkin_rt1800.dts b/target/linux/ramips/dts/mt7621_belkin_rt1800.dts
new file mode 100644
index 0000000000..7bf7d89445
--- /dev/null
+++ b/target/linux/ramips/dts/mt7621_belkin_rt1800.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>
+#include <dt-bindings/leds/common.h>
+
+/ {
+	compatible = "belkin,rt1800", "mediatek,mt7621-soc";
+	model = "Belkin RT1800";
+
+	aliases {
+		led-boot = &led_power;
+		led-failsafe = &led_power;
+		led-running = &led_power;
+		led-upgrade = &led_power;
+	};
+
+	chosen {
+		bootargs = "console=ttyS0,115200";
+	};
+
+	keys {
+		compatible = "gpio-keys";
+
+		reset {
+			label = "reset";
+			gpios = <&gpio 6 GPIO_ACTIVE_LOW>;
+			linux,code = <KEY_RESTART>;
+		};
+
+		wps {
+			label = "wps";
+			gpios = <&gpio 18 GPIO_ACTIVE_LOW>;
+			linux,code = <KEY_WPS_BUTTON>;
+		};
+	};
+
+	leds {
+		compatible = "gpio-leds";
+
+		led_power: led-power {
+			label = "white:power";
+			gpios = <&gpio 14 GPIO_ACTIVE_LOW>;
+			default-state = "on";
+		};
+
+		led-wan {
+			color = <LED_COLOR_ID_WHITE>;
+			function = LED_FUNCTION_WAN;
+			gpios = <&switch0 0 GPIO_ACTIVE_LOW>;
+		};
+	};
+};
+
+&nand {
+	status = "okay";
+
+	partitions {
+		compatible = "fixed-partitions";
+		#address-cells = <1>;
+		#size-cells = <1>;
+
+		partition@0 {
+			label = "Boot";
+			reg = <0x0 0x80000>;
+			read-only;
+		};
+
+		partition@80000 {
+			label = "Config";
+			reg = <0x80000 0x80000>;
+		};
+
+		factory: partition@100000 {
+			label = "Factory";
+			reg = <0x100000 0x80000>;
+			read-only;
+		};
+
+		partition@180000 {
+			label = "firmware";
+			reg = <0x180000 0x3000000>;
+
+			compatible = "fixed-partitions";
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			partition@0 {
+				label = "kernel";
+				reg = <0x0 0x400000>;
+			};
+
+			partition@400000 {
+				label = "ubi";
+				reg = <0x400000 0x2c00000>;
+			};
+		};
+
+		partition@3180000 {
+			label = "alt_firmware";
+			reg = <0x3180000 0x3000000>;
+			read-only;
+		};
+
+		partition@6180000 {
+			label = "cbtinfo";
+			reg = <0x6180000 0x80000>;
+			read-only;
+		};
+		/* seems to be the end here. Can't read past 0x6200000 */
+	};
+};
+
+&pcie {
+	status = "okay";
+};
+
+&pcie1 {
+	wifi@0,0 {
+		compatible = "mediatek,mt76";
+		reg = <0x0000 0 0 0 0>;
+		mediatek,mtd-eeprom = <&factory 0x0000>;
+	};
+};
+
+&gmac1 {
+	status = "okay";
+	label = "wan";
+	phy-handle = <&ethphy0>;
+};
+
+&mdio {
+	ethphy0: ethernet-phy@0 {
+		reg = <0>;
+	};
+};
+
+&switch0 {
+	gpio-controller;
+	#gpio-cells = <2>;
+
+	ports {
+		port@1 {
+			status = "okay";
+			label = "lan4";
+		};
+
+		port@2 {
+			status = "okay";
+			label = "lan3";
+		};
+
+		port@3 {
+			status = "okay";
+			label = "lan2";
+		};
+
+		port@4 {
+			status = "okay";
+			label = "lan1";
+		};
+	};
+};