ath79: add support for D-Link DIR-842 C2

Hardware spec of DIR-842 C2:
SoC: QCA9563
DRAM: 128MB DDR2
Flash: 16MB SPI-NOR
Switch: QCA8337N
WiFi 5.8GHz: QCA9888
WiFi 2.4Ghz: QCA9563
USB: 2.0

Flash instructions:

1. Upgrade the factory.bin through the factory web interface or
   the u-boot failsafe interface.
   The firmware will boot up correctly for the first time.
   Do not power off the device after OpenWrt has booted.
   Otherwise the u-boot will enter failsafe mode as the checksum
   of the firmware has been changed.
2. Upgrade the sysupgrade.bin in OpenWrt.
   After upgrading completes the u-boot won't complain about the
   firmware checksum and it's OK to use now.
3. If you powered off the device before upgrading the sysupgrade.bin,
   just upgrade the factory.bin through the u-boot failsafe interface
   and then goto step 2.

Signed-off-by: Jackson Lim <jackcolentern@gmail.com>
[Reword reset-hog comment, fix formatting]
Signed-off-by: David Bauer <mail@david-bauer.net>

target/linux/ath79/base-files/etc/board.d/01_leds

@@ -59,6 +59,7 @@ comfast,cf-e5)
 	ucidef_set_led_rssi "rssimedium" "RSSIMEDIUM" "$boardname:blue:rssi1" "wlan0" "33" "100"
 	ucidef_set_led_rssi "rssihigh" "RSSIHIGH" "$boardname:blue:rssi2" "wlan0" "66" "100"
 	;;
+dlink,dir-842-c2|\
 dlink,dir-859-a1)
 	ucidef_set_led_switch "internet" "WAN" "$boardname:green:internet" "switch0" "0x20"
 	;;

target/linux/ath79/base-files/etc/board.d/02_network

@@ -112,6 +112,7 @@ ath79_setup_interfaces()
 		;;
 	dlink,dir-825-c1|\
 	dlink,dir-835-a1|\
+	dlink,dir-842-c2|\
 	dlink,dir-859-a1|\
 	engenius,epg5000|\
 	tplink,archer-c2-v3|\
@@ -303,6 +304,7 @@ ath79_setup_macs()
 		lan_mac=$(mtd_get_mac_text "mac" 4)
 		wan_mac=$(mtd_get_mac_text "mac" 24)
 		;;
+	dlink,dir-842-c2|\
 	dlink,dir-859-a1|\
 	nec,wg1200cr|\
 	wd,mynet-n750)

target/linux/ath79/base-files/etc/hotplug.d/firmware/10-ath9k-eeprom

@@ -105,6 +105,7 @@ case "$FIRMWARE" in
 		ath9k_eeprom_extract "art" 4096 1088
 		ath9k_patch_fw_mac_crc $(mtd_get_mac_text "mac" 4) 2
 		;;
+	dlink,dir-842-c2|\
 	dlink,dir-859-a1|\
 	nec,wg1200cr|\
 	wd,mynet-n750)

target/linux/ath79/base-files/etc/hotplug.d/firmware/11-ath10k-caldata

@@ -189,6 +189,7 @@ case "$FIRMWARE" in
 	;;
 "ath10k/pre-cal-pci-0000:00:00.0.bin")
 	case $board in
+	dlink,dir-842-c2|\
 	nec,wg1200cr)
 		ath10kcal_extract "art" 20480 12064
 		ath10kcal_patch_mac_crc $(mtd_get_mac_ascii devdata wlan5mac)

target/linux/ath79/dts/qca9563_dlink_dir-842-c2.dts

@@ -0,0 +1,188 @@
+// 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"
+
+/ {
+	model = "D-Link DIR-842 C2";
+	compatible = "dlink,dir-842-c2", "qca,qca9563";
+
+	aliases {
+		led-boot = &power;
+		led-failsafe = &power;
+		led-running = &power;
+		led-upgrade = &power;
+	};
+
+	chosen {
+		bootargs = "console=ttyS0,115200n8";
+	};
+
+	leds {
+		compatible = "gpio-leds";
+
+		wps {
+			label = "dir-842-c2:green:wps";
+			gpios = <&gpio 8 GPIO_ACTIVE_LOW>;
+		};
+
+		power: power {
+			label = "dir-842-c2:green:power";
+			gpios = <&gpio 15 GPIO_ACTIVE_LOW>;
+		};
+
+		internet {
+			label = "dir-842-c2:green:internet";
+			gpios = <&gpio 16 GPIO_ACTIVE_LOW>;
+		};
+
+		wlan {
+			label = "dir-842-c2:green:wlan";
+			gpios = <&gpio 19 GPIO_ACTIVE_LOW>;
+			linux,default-trigger = "phy0tpt";
+		};
+	};
+
+	keys {
+		compatible = "gpio-keys";
+
+		wps {
+			linux,code = <KEY_WPS_BUTTON>;
+			gpios = <&gpio 1 GPIO_ACTIVE_LOW>;
+			debounce-interval = <60>;
+		};
+
+		reset {
+			linux,code = <KEY_RESTART>;
+			gpios = <&gpio 2 GPIO_ACTIVE_LOW>;
+			debounce-interval = <60>;
+		};
+	};
+
+	// Pull up on boot - otherwise the reset button won't work
+	reset-button {
+		gpio-hog;
+		output-high;
+		gpios = <11 GPIO_ACTIVE_LOW>;
+		line-name = "reset-button";
+	};
+};
+
+&uart {
+	status = "okay";
+};
+
+&pcie {
+	status = "okay";
+};
+
+&spi {
+	status = "okay";
+	num-cs = <1>;
+
+	flash@0 {
+		compatible = "jedec,spi-nor";
+		reg = <0>;
+		spi-max-frequency = <30000000>;
+
+		partitions {
+			compatible = "fixed-partitions";
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			partition@0 {
+				label = "u-boot";
+				reg = <0x000000 0x40000>;
+				read-only;
+			};
+
+			partition@40000 {
+				label = "u-boot-env";
+				reg = <0x040000 0x10000>;
+				read-only;
+			};
+
+			partition@50000 {
+				label = "devdata";
+				reg = <0x050000 0x10000>;
+				read-only;
+			};
+
+			partition@60000 {
+				label = "devconf";
+				reg = <0x060000 0x10000>;
+				read-only;
+			};
+
+			partition@70000 {
+				label = "misc";
+				reg = <0x070000 0x10000>;
+				read-only;
+			};
+
+			partition@80000 {
+				compatible = "seama";
+				label = "firmware";
+				reg = <0x080000 0xf50000>;
+			};
+
+			art: partition@fd0000 {
+				label = "art";
+				reg = <0xfd0000 0x010000>;
+				read-only;
+			};
+
+			partition@fe0000 {
+				label = "reserved";
+				reg = <0xfe0000 0x20000>;
+				read-only;
+			};
+		};
+	};
+};
+
+&mdio0 {
+	status = "okay";
+
+	phy-mask = <0>;
+
+	phy0: ethernet-phy@0 {
+		reg = <0>;
+		qca,mib-poll-interval = <500>;
+
+		qca,ar8327-initvals = <
+			0x04 0x00080080 /* PORT0 PAD MODE CTRL */
+			0x10 0x81000080 /* POWER_ON_STRIP */
+			0x50 0xcc35cc35 /* LED_CTRL0 */
+			0x54 0xcb37cb37 /* LED_CTRL1 */
+			0x58 0x00000000 /* LED_CTRL2 */
+			0x5c 0x00f3cf00 /* LED_CTRL3 */
+			0x7c 0x0000007e /* PORT0_STATUS */
+			>;
+	};
+};
+
+&eth0 {
+	status = "okay";
+
+	pll-data = <0x03000101 0x00000101 0x00001919>;
+
+	phy-mode = "sgmii";
+	phy-handle = <&phy0>;
+};
+
+&wmac {
+	status = "okay";
+	qca,no-eeprom;
+};
+
+&usb_phy0 {
+	status = "okay";
+};
+
+&usb0 {
+	status = "okay";
+};

target/linux/ath79/image/generic.mk

@@ -355,6 +355,29 @@ define Device/dlink_dir-859-a1
 endef
 TARGET_DEVICES += dlink_dir-859-a1
 
+define Device/dlink_dir-842-c2
+  ATH_SOC := qca9563
+  DEVICE_VENDOR := D-Link
+  DEVICE_MODEL := DIR-842
+  DEVICE_VARIANT := C2
+  KERNEL := kernel-bin | append-dtb | relocate-kernel | lzma
+  KERNEL_INITRAMFS := $$(KERNEL) | seama
+  IMAGES += factory.bin
+  SEAMA_MTDBLOCK := 5
+  SEAMA_SIGNATURE := wrgac65_dlink.2015_dir842
+  # 64 bytes offset:
+  # - 28 bytes seama_header
+  # - 36 bytes of META data (4-bytes aligned)
+  IMAGE/default := append-kernel | uImage lzma | pad-offset $$$$(BLOCKSIZE) 64 | append-rootfs
+  IMAGE/sysupgrade.bin := \
+	$$(IMAGE/default) | seama | pad-rootfs | append-metadata | check-size $$$$(IMAGE_SIZE)
+  IMAGE/factory.bin := \
+	$$(IMAGE/default) | pad-rootfs -x 64 | seama | seama-seal | check-size $$$$(IMAGE_SIZE)
+  IMAGE_SIZE := 15680k
+  DEVICE_PACKAGES := kmod-usb2 kmod-ath10k-ct ath10k-firmware-qca9888-ct
+endef
+TARGET_DEVICES += dlink_dir-842-c2
+
 define Device/elecom_wrc-1750ghbk2-i
   ATH_SOC := qca9563
   DEVICE_VENDOR := ELECOM