ramips: add support for ipTIME A3

ipTIME A3 is a 2.4/5GHz band AC1200 router, based on MediaTek
MT7628AN.

Specifications:
- SoC: MT7628AN
- RAM: DDR2 64MB
- Flash: SPI NOR 8MB
- WiFi:
  - 2.4GHz: SoC internal
  - 5GHz: MT7612EN
- Ethernet: 3x 10/100Mbps
  - Switch: SoC internal
- UART:
  - J1: 3.3V, TX, RX, GND (3.3V is the square pad) / 57600 8N1

Installation via web interface:
1.  Flash **initramfs** image through the stock web interface.
2.  Boot into OpenWrt and perform sysupgrade with sysupgrade image.

Revert to stock firmware:
1.  Perform sysupgrade with stock image.

Signed-off-by: Sungbo Eo <mans0n@gorani.run>

1 files changed, 36 insertions, 0 deletions

diff --git a/target/linux/ramips/dts/mt7628an_iptime_a3.dts b/target/linux/ramips/dts/mt7628an_iptime_a3.dts
new file mode 100644
index 0000000000..a4d8458ded
--- /dev/null
+++ b/target/linux/ramips/dts/mt7628an_iptime_a3.dts
@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: GPL-2.0-or-later OR MIT
+/dts-v1/;
+
+#include "mt7628an_iptime.dtsi"
+
+/ {
+	compatible = "iptime,a3", "mediatek,mt7628an-soc";
+	model = "ipTIME A3";
+
+	aliases {
+		led-boot = &led_cpu;
+		led-failsafe = &led_cpu;
+		led-running = &led_cpu;
+		led-upgrade = &led_cpu;
+	};
+
+	leds {
+		compatible = "gpio-leds";
+
+		led_cpu: cpu {
+			label = "a3:blue:cpu";
+			gpios = <&gpio0 11 GPIO_ACTIVE_LOW>;
+		};
+
+		wlan {
+			label = "a3:blue:wlan";
+			gpios = <&gpio1 14 GPIO_ACTIVE_LOW>;
+			linux,default-trigger = "phy0tpt";
+		};
+	};
+};
+
+&esw {
+	mediatek,portmap = <0x3e>;
+	mediatek,portdisable = <0x32>;
+};