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, 109 insertions, 0 deletions

diff --git a/target/linux/ramips/dts/mt7628an_iptime.dtsi b/target/linux/ramips/dts/mt7628an_iptime.dtsi
new file mode 100644
index 0000000000..05d6aa533a
--- /dev/null
+++ b/target/linux/ramips/dts/mt7628an_iptime.dtsi
@@ -0,0 +1,109 @@
+// SPDX-License-Identifier: GPL-2.0-or-later OR MIT
+/dts-v1/;
+
+#include "mt7628an.dtsi"
+
+#include <dt-bindings/gpio/gpio.h>
+#include <dt-bindings/input/input.h>
+
+/ {
+	aliases {
+		label-mac-device = &ethernet;
+	};
+
+	keys {
+		compatible = "gpio-keys";
+
+		reset {
+			label = "reset";
+			gpios = <&gpio1 6 GPIO_ACTIVE_LOW>;
+			linux,code = <KEY_RESTART>;
+			debounce-interval = <60>;
+		};
+
+		wps {
+			label = "wps";
+			gpios = <&gpio1 13 GPIO_ACTIVE_LOW>;
+			linux,code = <KEY_WPS_BUTTON>;
+			debounce-interval = <60>;
+		};
+	};
+};
+
+&spi0 {
+	status = "okay";
+
+	flash@0 {
+		compatible = "jedec,spi-nor";
+		reg = <0>;
+		spi-max-frequency = <40000000>;
+
+		partitions {
+			compatible = "fixed-partitions";
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			uboot: partition@0 {
+				label = "u-boot";
+				reg = <0x0 0x20000>;
+				read-only;
+			};
+
+			partition@20000 {
+				label = "config";
+				reg = <0x20000 0x10000>;
+				read-only;
+			};
+
+			factory: partition@30000 {
+				label = "factory";
+				reg = <0x30000 0x10000>;
+				read-only;
+			};
+
+			partition@40000 {
+				compatible = "denx,uimage";
+				label = "firmware";
+				reg = <0x40000 0x7c0000>;
+			};
+		};
+	};
+};
+
+&pinctrl {
+	state_default: pinctrl0 {
+		gpio {
+			ralink,group = "uart1", "wdt";
+			ralink,function = "gpio";
+		};
+	};
+};
+
+&ehci {
+	status = "disabled";
+};
+
+&ohci {
+	status = "disabled";
+};
+
+&ethernet {
+	mtd-mac-address = <&uboot 0x1fc20>;
+};
+
+&pcie {
+	status = "okay";
+};
+
+&pcie0 {
+	wifi@0,0 {
+		compatible = "mediatek,mt76";
+		reg = <0x0000 0 0 0 0>;
+		mediatek,mtd-eeprom = <&factory 0x8000>;
+		ieee80211-freq-limit = <5000000 6000000>;
+	};
+};
+
+&wmac {
+	status = "okay";
+};