ramips: add support for TP-Link TL-WR902AC v3

TP-Link TL-WR902AC v3 is a pocket-size dual-band (AC750) router
based on MediaTek MT7628N + MT7650E.

Specification:
- MediaTek MT7628N/N (580 Mhz)
- 64 MB of RAM
- 8 MB of FLASH
- 2T2R 2.4 GHz and 1T1R 5 GHz
- 1x 10/100 Mbps Ethernet

* MT7650 ac chip isn't not supported by LEDE/OpenWrt at the moment.
  Therefore 5Ghz won' work.

Flash instruction:

The only way to flash LEDE image in TL-WR902AC v3 is to use
tftp recovery mode in U-Boot:

1. Configure PC with static IP 192.168.0.66/24 and tftp server.
2. Rename "openwrt-ramips-mt76x8-tplink_tl-wr902ac-v3-squashfs-tftp-recovery.bin"
   to "tp_recovery.bin" and place it in tftp server directory.
3. Connect PC with the LAN port, press the reset button, power up
   the router and keep button pressed for around 6-7 seconds, until
   device starts downloading the file.
4. Router will download file from server, write it to flash and reboot.

Signed-off-by: Peter Lundkvist <peter.lundkvist@gmail.com>
[drop p2led_an pinmux, this pin isn't used as gpio, fix whitespace issues]
Signed-off-by: Mathias Kresin <dev@kresin.me>

1 files changed, 102 insertions, 0 deletions

diff --git a/target/linux/ramips/dts/TL-WR902ACV3.dts b/target/linux/ramips/dts/TL-WR902ACV3.dts
new file mode 100644
index 0000000000..8ff3576595
--- /dev/null
+++ b/target/linux/ramips/dts/TL-WR902ACV3.dts
@@ -0,0 +1,102 @@
+/dts-v1/;
+
+#include "TPLINK-8M.dtsi"
+
+#include <dt-bindings/gpio/gpio.h>
+#include <dt-bindings/input/input.h>
+
+/ {
+	compatible = "tplink,tl-wr902ac-v3", "mediatek,mt7628an-soc";
+	model = "TP-Link TL-WR902AC v3";
+
+	gpio-keys-polled {
+		compatible = "gpio-keys-polled";
+		#address-cells = <1>;
+		#size-cells = <0>;
+		poll-interval = <20>;
+
+		reset {
+			label = "reset";
+			gpios = <&gpio1 6 GPIO_ACTIVE_LOW>;
+			linux,code = <KEY_RESTART>;
+		};
+
+		sw1 {
+			label = "sw1";
+			gpios = <&gpio0 2 GPIO_ACTIVE_LOW>;
+			linux,code = <BTN_0>;
+		};
+
+		sw2 {
+			label = "sw2";
+			gpios = <&gpio0 3 GPIO_ACTIVE_LOW>;
+			linux,code = <BTN_1>;
+		};
+	};
+
+	gpio-leds {
+		compatible = "gpio-leds";
+
+		lan {
+			label = "tl-wr902ac-v3:green:lan";
+			gpios = <&gpio0 5 GPIO_ACTIVE_HIGH>;
+		};
+
+		power {
+			label = "tl-wr902ac-v3:green:power";
+			gpios = <&gpio1 14 GPIO_ACTIVE_LOW>;
+		};
+
+		usb {
+			label = "tl-wr902ac-v3:green:usb";
+			gpios = <&gpio1 11 GPIO_ACTIVE_LOW>;
+		};
+
+		wan {
+			label = "tl-wr902ac-v3:green:wan";
+			gpios = <&gpio1 7 GPIO_ACTIVE_LOW>;
+		};
+
+		wlan {
+			label = "tl-wr902ac-v3:green:wlan";
+			gpios = <&gpio1 12 GPIO_ACTIVE_LOW>;
+		};
+
+		wps {
+			label = "tl-wr902ac-v3:green:wps";
+			gpios = <&gpio0 4 GPIO_ACTIVE_LOW>;
+		};
+	};
+};
+
+&pinctrl {
+	state_default: pinctrl0 {
+		gpio {
+			ralink,group = "i2c", "i2s", "p0led_an", "p4led_an", "uart1", "wdt", "wled_an";
+			ralink,function = "gpio";
+		};
+	};
+};
+
+&ehci {
+	status = "okay";
+};
+
+&ohci {
+	status = "okay";
+};
+
+&pcie {
+	status = "okay";
+
+	pcie-bridge {
+		mt76@1,0 {
+			reg = <0x0000 0 0 0 0>;
+			device_type = "pci";
+			mediatek,mtd-eeprom = <&factory 0x28000>;
+			ieee80211-freq-limit = <5000000 6000000>;
+			mtd-mac-address = <&factory 0xf100>;
+			mtd-mac-address-increment = <(-1)>;
+		};
+	};
+};