ramips: add support for ELECOM WRC-1900GST

ELECOM WRC-1900GST is a wireless router, based on Mediatek MT7621A.
This is almost same as WRC-2533GST except wireless specs.

Specifications:

  - SoC : MT7621A (four logical CPU cores)
  - RAM : 128MiB
  - ROM : 16MiB of SPI NOR-FLASH
  - wireless :
          5GHz : 3T3R up to 1300Mbps/11ac with MT7615
          2.4GHz : 3T3R up to 600Mbps/11n with MT7615
  - Ethernet : 5 ports, all ports is capable of 1000base-T
  - Ether switch : MT7530 (MT7621A built-in)
  - LEDs : 4 LEDs
  - buttons : 2 buttons and 1 slide-switch
  - UART : header is on PCB, 57600bps

Flash instruction using factory image:

 1. Connect the computer to the LAN port of WRC-1900GST
 2. Connect power cable to WRC-1900GST and turn on it
 3. Access to "https://192.168.2.1/" and open firmware update
    page ("ファームウェア更新")
 4. Select the OpenWrt factory image and click apply ("適用")
    button
 5. Wait ~150 seconds to complete flashing

Signed-off-by: NOGUCHI Hiroshi <drvlabo@gmail.com>

1 files changed, 176 insertions, 0 deletions

diff --git a/target/linux/ramips/dts/elecom_wrc-gst.dtsi b/target/linux/ramips/dts/elecom_wrc-gst.dtsi
new file mode 100644
index 0000000000..6c52c1c00b
--- /dev/null
+++ b/target/linux/ramips/dts/elecom_wrc-gst.dtsi
@@ -0,0 +1,176 @@
+/dts-v1/;
+
+#include "mt7621.dtsi"
+
+#include <dt-bindings/gpio/gpio.h>
+#include <dt-bindings/input/input.h>
+
+/ {
+	aliases {
+		led-status = &led_power_green;
+	};
+
+	memory@0 {
+		device_type = "memory";
+		reg = <0x0 0x8000000>;
+	};
+
+	chosen {
+		bootargs = "console=ttyS0,57600";
+	};
+
+	gpio-leds {
+		compatible = "gpio-leds";
+
+		led_power_green: power_green {
+			label = "wrc-gst:green:power";
+			gpios = <&gpio0 7 GPIO_ACTIVE_HIGH>;
+		};
+
+		power_blue {
+			label = "wrc-gst:blue:power";
+			gpios = <&gpio0 8 GPIO_ACTIVE_HIGH>;
+		};
+
+		wps {
+			label = "wrc-gst:red:wps";
+			gpios = <&gpio0 15 GPIO_ACTIVE_HIGH>;
+		};
+
+		power_red {
+			label = "wrc-gst:red:power";
+			gpios = <&gpio0 16 GPIO_ACTIVE_HIGH>;
+		};
+	};
+
+	gpio-keys-polled {
+		compatible = "gpio-keys-polled";
+		poll-interval = <20>;
+
+		reset {
+			label = "reset";
+			gpios = <&gpio0 13 GPIO_ACTIVE_LOW>;
+			linux,code = <KEY_RESTART>;
+		};
+
+		wps {
+			label = "wps";
+			gpios = <&gpio0 18 GPIO_ACTIVE_LOW>;
+			linux,code = <KEY_WPS_BUTTON>;
+		};
+
+		client {
+			label = "client";
+			gpios = <&gpio1 9 GPIO_ACTIVE_LOW>;
+			linux,code = <BTN_0>;
+			linux,input-type = <EV_SW>;
+		};
+
+		ap {
+			label = "ap";
+			gpios = <&gpio1 10 GPIO_ACTIVE_LOW>;
+			linux,code = <BTN_0>;
+			linux,input-type = <EV_SW>;
+		};
+
+		extender {
+			label = "extender";
+			gpios = <&gpio1 11 GPIO_ACTIVE_LOW>;
+			linux,code = <BTN_0>;
+			linux,input-type = <EV_SW>;
+		};
+
+		router {
+			label = "router";
+			gpios = <&gpio1 12 GPIO_ACTIVE_LOW>;
+			linux,code = <BTN_0>;
+			linux,input-type = <EV_SW>;
+		};
+	};
+};
+
+&ethernet {
+	mtd-mac-address = <&factory 0xe000>;
+};
+
+&spi0 {
+	status = "okay";
+
+	m25p80@0 {
+		compatible = "jedec,spi-nor";
+		reg = <0>;
+		spi-max-frequency = <10000000>;
+		m25p,chunked-io = <32>;
+
+		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;
+			};
+
+			factory: partition@40000 {
+				label = "factory";
+				reg = <0x40000 0x10000>;
+				read-only;
+			};
+
+			partition@50000 {
+				label = "firmware";
+				reg = <0x50000 0xb00000>;
+			};
+
+			partition@b50000 {
+				label = "tm_pattern";
+				reg = <0xb50000 0x380000>;
+				read-only;
+			};
+
+			partition@ed0000 {
+				label = "tm_key";
+				reg = <0xed0000 0x80000>;
+				read-only;
+			};
+
+			partition@f50000 {
+				label = "art_block";
+				reg = <0xf50000 0x30000>;
+				read-only;
+			};
+
+			partition@f80000 {
+				label = "user_data";
+				reg = <0xf80000 0x80000>;
+				read-only;
+			};
+		};
+	};
+};
+
+&pinctrl {
+	state_default: pinctrl0 {
+		gpio {
+			ralink,group = "uart3", "jtag", "wdt", "sdhci";
+			ralink,function = "gpio";
+		};
+	};
+};
+
+&pcie {
+	status = "okay";
+	/* WRC-xxxxGST has MT7615 for 2.4/5 GHz wifi, but it's not supported */
+};
+
+&xhci {
+	status = "disabled";
+};