ramips: add support for ipTIME A104ns

ipTIME A104ns is a 2.4/5GHz band AC750 router, based on MediaTek MT7620A.

Specifications:
- SoC: MT7620A
- RAM: DDR2 64MB
- Flash: SPI NOR 8MB
- WiFi:
  - 2.4GHz: SoC internal
  - 5GHz: MT7610EN
- Ethernet: 5x 10/100Mbps
  - Switch: SoC internal
- USB: 1x 2.0
- UART:
  - J2: 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.

In contrast to to-be-supported A1004ns, the A104ns has no usable
value in 0x1fc40 (uboot), so wan_mac needs to be calculated.
Also note that GPIOs for the LEDs really are inverted compared to
the A1004ns.

Signed-off-by: Sungbo Eo <mans0n@gorani.run>
[moved state_default to device DTS, reordered properties in wmac,
added comment about wan_mac and LED GPIOs]
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>

2 files changed, 145 insertions, 0 deletions

diff --git a/target/linux/ramips/dts/mt7620a_iptime.dtsi b/target/linux/ramips/dts/mt7620a_iptime.dtsi
new file mode 100644
index 0000000000..5a6fdacb52
--- /dev/null
+++ b/target/linux/ramips/dts/mt7620a_iptime.dtsi
@@ -0,0 +1,86 @@
+// SPDX-License-Identifier: GPL-2.0-or-later OR MIT
+
+#include "mt7620a.dtsi"
+
+#include <dt-bindings/gpio/gpio.h>
+#include <dt-bindings/input/input.h>
+
+/ {
+	aliases {
+		label-mac-device = &ethernet;
+	};
+};
+
+&gpio1 {
+	status = "okay";
+};
+
+&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;
+			};
+
+			firmware: partition@30000 {
+				compatible = "denx,uimage";
+				label = "firmware";
+			};
+		};
+	};
+};
+
+&ethernet {
+	mtd-mac-address = <&uboot 0x1fc20>;
+};
+
+&ehci {
+	status = "okay";
+};
+
+&ohci {
+	status = "okay";
+};
+
+&pcie {
+	status = "okay";
+};
+
+&pcie0 {
+	wifi@0,0 {
+		compatible = "mediatek,mt76";
+		reg = <0x0000 0 0 0 0>;
+		mediatek,mtd-eeprom = <&uboot 0x1f800>;
+		ieee80211-freq-limit = <5000000 6000000>;
+
+		led {
+			led-sources = <0>;
+			led-active-low;
+		};
+	};
+};
+
+&wmac {
+	pinctrl-names = "default";
+	pinctrl-0 = <&wled_pins>;
+
+	ralink,mtd-eeprom = <&uboot 0x1f400>;
+};
diff --git a/target/linux/ramips/dts/mt7620a_iptime_a104ns.dts b/target/linux/ramips/dts/mt7620a_iptime_a104ns.dts
new file mode 100644
index 0000000000..14b5071007
--- /dev/null
+++ b/target/linux/ramips/dts/mt7620a_iptime_a104ns.dts
@@ -0,0 +1,59 @@
+// SPDX-License-Identifier: GPL-2.0-or-later OR MIT
+/dts-v1/;
+
+#include "mt7620a_iptime.dtsi"
+
+/ {
+	compatible = "iptime,a104ns", "ralink,mt7620a-soc";
+	model = "ipTIME A104ns";
+
+	aliases {
+		led-boot = &led_cpu;
+		led-failsafe = &led_cpu;
+		led-running = &led_cpu;
+		led-upgrade = &led_cpu;
+	};
+
+	leds {
+		compatible = "gpio-leds";
+
+		usb {
+			label = "a104ns:blue:usb";
+			gpios = <&gpio0 11 GPIO_ACTIVE_LOW>;
+			trigger-sources = <&ohci_port1>, <&ehci_port1>;
+			linux,default-trigger = "usbport";
+		};
+
+		led_cpu: cpu {
+			label = "a104ns:blue:cpu";
+			gpios = <&gpio1 15 GPIO_ACTIVE_LOW>;
+		};
+	};
+
+	keys {
+		compatible = "gpio-keys";
+
+		wps {
+			label = "wps";
+			gpios = <&gpio0 12 GPIO_ACTIVE_LOW>;
+			linux,code = <KEY_WPS_BUTTON>;
+		};
+
+		reset {
+			label = "reset";
+			gpios = <&gpio0 13 GPIO_ACTIVE_LOW>;
+			linux,code = <KEY_RESTART>;
+		};
+	};
+};
+
+&firmware {
+	reg = <0x30000 0x7d0000>;
+};
+
+&state_default {
+	gpio {
+		ralink,group = "uartf", "spi refclk";
+		ralink,function = "gpio";
+	};
+};