ath79: add support for Comfast E314N-v2

Taken code from https://patchwork.ozlabs.org/patch/884850/ that was never
pushed by the author, and adapted to ath79.

The Comfast E314N-V2 is a 2.4 GHz 2x2 radio with a built-in directional
antenna and a second Ethernet port - very similar to the Ubiquiti
NanoStation M2. The Ethernet port features a pass-through PoE capability,
enabled or disabled with a slide switch.

Specifications :
- System-On-Chip: Qualcomm/Atheros QCA9531
- CPU/Speed: 650 MHz
- Flash size: 8 MiB
- RAM: 64 MiB
- 2 Ethernet 1Gbp
- 1 reset button
- 1 switch to choose PoE from LAN or Wan. 48Vdc
- Wifi 2.4 Ghz (b/g/n)
- UART inside the box (3.3V, pins marked on the PCB)

Firmware can be flashed on these units by the following method:
1.) Apply power to the unit
2.) Immediately AFTER applying power, hold down the reset button
3.) The WAN, LAN, and wireless lights will flash - wait three seconds
    (three flashes) and then release the button.
4.) After a second, the lights will flutter quickly and the unit will be
    visible at 192.168.1.1. A web page will be available to enable quick
    and simple uploading and flashing of firmware.

During the boot process, these units also look for a tftp server at
192.168.1.10. If one is present, the firmware can be uploaded as a file
called firmware-auto.bin

Signed-off-by: Joan Moreau <jom@grosjo.net>
[wrapped commit message - fix commit title capitalization]
Signed-off-by: David Bauer <mail@david-bauer.net>

1 files changed, 154 insertions, 0 deletions

diff --git a/target/linux/ath79/dts/qca9531_comfast_cf-e314n-v2.dts b/target/linux/ath79/dts/qca9531_comfast_cf-e314n-v2.dts
new file mode 100644
index 0000000000..fa98f75238
--- /dev/null
+++ b/target/linux/ath79/dts/qca9531_comfast_cf-e314n-v2.dts
@@ -0,0 +1,154 @@
+// SPDX-License-Identifier: GPL-2.0-or-later OR MIT
+/dts-v1/;
+
+#include <dt-bindings/gpio/gpio.h>
+#include <dt-bindings/input/input.h>
+
+#include "qca953x.dtsi"
+
+/ {
+	compatible = "comfast,cf-e314n-v2", "qca,qca9531";
+	model = "COMFAST CF-E314N v2";
+
+	aliases {
+		serial0 = &uart;
+		led-boot = &system;
+		led-failsafe = &system;
+		led-upgrade = &system;
+	};
+
+	leds {
+		compatible = "gpio-leds";
+
+		pinctrl-names = "default";
+		pinctrl-0 = <&jtag_disable_pins &led_rssilow_pin &led_rssimediumhigh_pin &led_rssihigh_pin>;
+
+		wan {
+			label = "cf-e314n-v2:green:wan";
+			gpios = <&gpio 3 GPIO_ACTIVE_LOW>;
+		};
+
+		lan {
+			label = "cf-e314n-v2:green:lan";
+			gpios = <&gpio 2 GPIO_ACTIVE_LOW>;
+		};
+
+		rssilow {
+			label = "cf-e314n-v2:red:signal1";
+			gpios = <&gpio 11 GPIO_ACTIVE_LOW>;
+		};
+
+		rssimediumlow {
+			label = "cf-e314n-v2:red:signal2";
+			gpios = <&gpio 12 GPIO_ACTIVE_LOW>;
+		};
+
+		rssimediumhigh {
+			label = "cf-e314n-v2:green:signal3";
+			gpios = <&gpio 13 GPIO_ACTIVE_LOW>;
+		};
+
+		system: rssihigh {
+			label = "cf-e314n-v2:green:signal4";
+			gpios = <&gpio 14 GPIO_ACTIVE_LOW>;
+		};
+
+		wlan {
+			label = "cf-e314n-v2:green:wlan";
+			gpios = <&gpio 0 GPIO_ACTIVE_LOW>;
+			linux,default-trigger = "phy0tpt";
+		};
+	};
+
+	keys {
+		compatible = "gpio-keys";
+
+		reset {
+			label = "reset";
+			linux,code = <KEY_RESTART>;
+			gpios = <&gpio 17 GPIO_ACTIVE_LOW>;
+			debounce-interval = <60>;
+		};
+	};
+};
+
+&pinmux {
+	led_rssilow_pin: pinmux_rssilow_pin {
+		pinctrl-single,bits = <0x8 0x0 0xff000000>;
+	};
+
+	led_rssimediumhigh_pin: pinmux_rssimediumhigh_pin {
+		pinctrl-single,bits = <0xc 0x0 0x00ff0000>;
+	};
+
+	led_rssihigh_pin: pinmux_rssihigh_pin {
+		pinctrl-single,bits = <0x10 0x0 0x000000ff>;
+	};
+};
+
+&spi {
+	status = "okay";
+	num-cs = <1>;
+
+	flash@0 {
+		compatible = "jedec,spi-nor";
+		reg = <0>;
+		spi-max-frequency = <25000000>;
+
+		partitions {
+			compatible = "fixed-partitions";
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			partition@0 {
+				label = "u-boot";
+				reg = <0x000000 0x010000>;
+				read-only;
+			};
+
+			art: partition@10000 {
+				label = "art";
+				reg = <0x010000 0x010000>;
+				read-only;
+			};
+
+			partition@20000 {
+				compatible = "denx,uimage";
+				label = "firmware";
+				reg = <0x020000 0x7c0000>;
+			};
+
+			partition@7e0000 {
+				label = "configs";
+				reg = <0x7e0000 0x010000>;
+				read-only;
+			};
+
+			partition@7f0000 {
+				label = "nvram";
+				reg = <0x7f0000 0x010000>;
+				read-only;
+			};
+		};
+	};
+};
+
+&uart {
+	status = "okay";
+};
+
+&eth0 {
+	status = "okay";
+	mtd-mac-address = <&art 0x0>;
+	phy-handle = <&swphy4>;
+};
+
+&eth1 {
+	status = "okay";
+	mtd-mac-address = <&art 0x6>;
+};
+
+&wmac {
+	status = "okay";
+	mtd-cal-data = <&art 0x1000>;
+};