ath79: support for TP-Link EAP225-Wall v2

TP-Link EAP225-Wall v2 is an AC1200 (802.11ac Wave-2) wall plate access
point. UART access and debricking require fine soldering.

The device was kindly provided for porting by Stijn Segers.

Device specifications:
* SoC: QCA9561 @ 775MHz
* RAM: 128MiB DDR2
* Flash: 16MiB SPI-NOR (GD25Q127CSIG)
* Wireless 2.4GHz (SoC): b/g/n, 2x2
* Wireless 5Ghz (QCA9886): a/n/ac, 2x2 MU-MIMO
* Ethernet (SoC): 4× 100Mbps
  * Eth0 (back): 802.3af/at PoE in
  * Eth1, Eth2 (bottom)
  * Eth3 (bottom): PoE out (can be toggled by GPIO)
* One status LED
* Two buttons (both work as failsafe)
  * LED button, implemented as KEY_BRIGHTNESS_TOGGLE
  * Reset button

Flashing instructions, requires recent firmware (tested on 1.20.0):
* ssh into target device and run `cliclientd stopcs`
* Upgrade with factory image via web interface

Debricking:
* Serial port can be soldered on PCB J4 (1: TXD, 2: RXD, 3: GND, 4: VCC)
    * Bridge unpopulated resistors R162 (TXD) and R165 (RXD)
      Do NOT bridge R164
    * Use 3.3V, 115200 baud, 8n1
* Interrupt bootloader by holding CTRL+B during boot
* tftp initramfs to flash via sysupgrade or LuCI web interface

MAC addresses:
MAC address (as on device label) is stored in device info partition at
an offset of 8 bytes. ath9k device has same address as ethernet, ath10k
uses address incremented by 1.
From OEM ifconfig:
    br0       Link encap:Ethernet  HWaddr 50:...:04
    eth0      Link encap:Ethernet  HWaddr 50:...:04
    wifi0     Link encap:UNSPEC  HWaddr 50-...-04-...
    wifi1     Link encap:UNSPEC  HWaddr 50-...-05-...

Signed-off-by: Sander Vanheule <sander@svanheule.net>
[fix IMAGE_SIZE]
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>

1 files changed, 146 insertions, 0 deletions

diff --git a/target/linux/ath79/dts/qca9561_tplink_eap225-wall-v2.dts b/target/linux/ath79/dts/qca9561_tplink_eap225-wall-v2.dts
new file mode 100644
index 0000000000..281f7f18fa
--- /dev/null
+++ b/target/linux/ath79/dts/qca9561_tplink_eap225-wall-v2.dts
@@ -0,0 +1,146 @@
+// 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 "qca956x.dtsi"
+
+/ {
+	compatible = "tplink,eap225-wall-v2", "qca,qca9561";
+	model = "TP-Link EAP225-Wall v2";
+
+	aliases {
+		label-mac-device = &eth1;
+		led-boot = &led_status;
+		led-failsafe = &led_status;
+		led-running = &led_status;
+		led-upgrade = &led_status;
+	};
+
+	keys {
+		compatible = "gpio-keys";
+
+		reset {
+			label = "Reset button";
+			linux,code = <KEY_RESTART>;
+			gpios = <&gpio 18 GPIO_ACTIVE_LOW>;
+			debounce-interval = <60>;
+		};
+
+		led {
+			label = "LED button";
+			linux,code = <KEY_LIGHTS_TOGGLE>;
+			gpios = <&gpio 21 GPIO_ACTIVE_LOW>;
+			debounce-interval = <60>;
+		};
+	};
+
+	leds {
+		compatible = "gpio-leds";
+
+		led_status: status {
+			label = "tp-link:white:status";
+			gpios = <&gpio 16 GPIO_ACTIVE_LOW>;
+			default-state = "on";
+		};
+	};
+
+	gpio-export {
+		compatible = "gpio-export";
+
+		poe_passthrough {
+			gpio-export,name = "tp-link:poe-passthrough:enable";
+			gpio-export,output = <0>;
+			gpios = <&gpio 20 GPIO_ACTIVE_HIGH>;
+		};
+	};
+};
+
+&uart {
+	status = "okay";
+};
+
+&pcie {
+	status = "okay";
+};
+
+&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 0x020000>;
+				read-only;
+			};
+
+			partition@20000 {
+				label = "partition-table";
+				reg = <0x020000 0x010000>;
+				read-only;
+			};
+
+			info: partition@30000 {
+				label = "info";
+				reg = <0x030000 0x010000>;
+				read-only;
+			};
+
+			partition@40000 {
+				compatible = "openwrt,elf";
+				label = "firmware";
+				reg = <0x040000 0xd80000>;
+			};
+
+			partition@dc0000 {
+				label = "config";
+				reg = <0xdc0000 0x030000>;
+				read-only;
+			};
+
+			/* df0000-f30000 undefined in vendor firmware */
+
+			partition@f30000 {
+				label = "mutil-log";
+				reg = <0xf30000 0x080000>;
+				read-only;
+			};
+
+			partition@fb0000 {
+				label = "oops";
+				reg = <0xfb0000 0x040000>;
+				read-only;
+			};
+
+			art: partition@ff0000 {
+				label = "art";
+				reg = <0xff0000 0x010000>;
+				read-only;
+			};
+		};
+	};
+};
+
+&eth1 {
+	status = "okay";
+
+	mtd-mac-address = <&info 0x8>;
+};
+
+&wmac {
+	status = "okay";
+
+	mtd-cal-data = <&art 0x1000>;
+	mtd-mac-address = <&info 0x8>;
+};