ramips: add support for JS76x8 series DEV boards

This commit adds support for the Jotale JS76x8 series development boards.
These devices have the following specifications:

- SOC: MT7628AN/NN, MT7688AN, MT7628DAN
- RAM of MT7628AN/NN and MT7688AN: 64/128/256 MB (DDR2)
- RAM of MT7628DAN: 64 MB (DDR2)
- FLASH:8/16/32 MB (SPI NOR)
- Ethernet:3x 10/100 Mbps ethernet ports (MT76x8 built-in switch)
- WIFI:1x 2T2R 2.4 GHz Wi-Fi
- LEDs:1x system status green LED, 1x wifi green LED,
       3x ethernet green LED
- Buttons:1x reset button
- 1x microSD slot
- 4x USB 2.0 port
- 1x mini-usb debug UART
- 1x DC jack for main power (DC 5V)
- 1x TTL/RS232 UART
- 1x TTL/RS485 UART
- 13x GPIO header
- 1x audio codec(wm8960)

Installation via OpenWrt:

The original firmware is OpenWrt, so both LuCI and sysupgrade can be used.

Installation via U-boot web:

1. Power on board with reset button pressed, release it
   after wifi led start blinking.
2. Setup static IP 192.168.1.123/4 on your PC.
3. Go to 192.168.1.8 in browser and upload "sysupgrade" image.

Installation via U-boot tftp:
1. Connect to serial console at the mini usb, which has been connected to UART0
   on board (115200 8N1)
2. Setup static IP 192.168.1.123/4 on your PC.
3. Place openwrt-firmware.bin on your PC tftp server (192.168.1.123).
3. Connect one of LAN ports on board to your PC.
4. Start terminal software (e.g. screen /dev/ttyUSB0 115200) on PC.
5. Apply power to board.
6. Interrupt U-boot with keypress of "2".
7. At u-boot prompts:
   Warning!! Erase Linux in Flash then burn new one. Are you sure?(Y/N) Y
   Input device IP (192.168.1.8) ==:192.168.1.8
   Input server IP (192.168.1.123) ==:192.168.1.123
   Input Linux Kernel filename (root_uImage) ==:openwrt-firmware.bin
8. board will download file from tftp server, write it to flash and reboot.

Signed-off-by: Robinson Wu <wurobinson@qq.com>
[add license to DTS files, fix state_default and reduce to the mimimum,
move phy0tpt trigger to DTS, drop ucidef_set_led_timer, fix network ports]
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>

1 files changed, 126 insertions, 0 deletions

diff --git a/target/linux/ramips/dts/mt7628an_jotale_js76x8.dtsi b/target/linux/ramips/dts/mt7628an_jotale_js76x8.dtsi
new file mode 100644
index 0000000000..61c5d7b7c4
--- /dev/null
+++ b/target/linux/ramips/dts/mt7628an_jotale_js76x8.dtsi
@@ -0,0 +1,126 @@
+// SPDX-License-Identifier: GPL-2.0-or-later OR MIT
+
+#include "mt7628an.dtsi"
+
+#include <dt-bindings/gpio/gpio.h>
+#include <dt-bindings/input/input.h>
+
+/ {
+	compatible = "jotale,js76x8", "mediatek,mt7628an-soc";
+
+	aliases {
+		led-boot = &led_system;
+		led-failsafe = &led_system;
+		led-running = &led_system;
+		led-upgrade = &led_system;
+	};
+
+	chosen {
+		bootargs = "console=ttyS0,115200";
+	};
+
+	leds {
+		compatible = "gpio-leds";
+
+		led_system: system {
+			label = "js76x8:green:system";
+			gpios = <&gpio 37 GPIO_ACTIVE_LOW>;
+		};
+
+		wifi {
+			label = "js76x8:green:wifi";
+			gpios = <&gpio 44 GPIO_ACTIVE_LOW>;
+			linux,default-trigger = "phy0tpt";
+		};
+	};
+
+	keys {
+		compatible = "gpio-keys";
+
+		reset {
+			label = "reset";
+			gpios = <&gpio 38 GPIO_ACTIVE_HIGH>;
+			linux,code = <KEY_RESTART>;
+		};
+	};
+};
+
+&state_default {
+	gpio {
+		groups = "refclk", "wdt", "wled_an";
+		function = "gpio";
+	};
+};
+
+&spi0 {
+	status = "okay";
+
+	pinctrl-names = "default";
+	pinctrl-0 = <&spi_pins>, <&spi_cs1_pins>;
+
+	flash@0 {
+		compatible = "jedec,spi-nor";
+		reg = <0>;
+		spi-max-frequency = <40000000>;
+		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;
+			};
+
+			firmware: partition@50000 {
+				compatible = "denx,uimage";
+				label = "firmware";
+				/* reg property is set based on flash size in DTS files */
+			};
+		};
+	};
+};
+
+&i2c {
+	status = "okay";
+};
+
+&i2s {
+	status = "okay";
+};
+
+&uart1 {
+	status = "okay";
+};
+
+&uart2 {
+	status = "okay";
+};
+
+&ethernet {
+	mtd-mac-address = <&factory 0x28>;
+};
+
+&sdhci {
+	status = "okay";
+	mediatek,cd-low;
+};
+
+&wmac {
+	status = "okay";
+};