ramips: Add support for TP-Link Archer C50 v6 (CA/EU/RU)

This adds support for the TP-Link Archer C50 v6 (CA/EU/RU).
(The ES variant is a rebranded Archer C54 and NOT supported.)

CPU:   MediaTek MT7628 (580MHz)
RAM:   64M DDR2
FLASH: 8M SPI
WiFi:  2.4GHz 2x2 MT7628 b/g/n integrated
WiFi:  5GHz 2x2 MT7613 a/n/ac
ETH:   1x WAN 4x LAN
LED:   Power, WiFi2, WiFi5, LAN, WAN, WPS
BTN:   WPS/WiFi, RESET
UART:  Near ETH ports, 115200 8n1, TP-Link pinout

Known issues
------------
- Enabling 5GHz WiFi may crash the system.
    Workaround: restart the box, 5GHz WiFi works properly afterwards.

Create Factory image
--------------------
As all installation methods require a U-Boot to be integrated into the
image (and we do not ship one with the image). We are not able to create
an image in the OpenWRT build-process.

Download a TP-Link image for your device variant (CA/EU or RU) from their
website and a OpenWRT sysupgrade image for the device
and build yourself a factory image like following:

TP-Link image:             tpl.bin
OpenWRT sysupgrade image:  owrt.bin

 > dd if=tpl.bin of=boot.bin bs=131584 count=1
 > cat owrt.bin >> boot.bin

Installing via Web-UI
---------------------
Upload the boot.bin via TP-Links firmware upgrade tool in the
web-interface.

Installing via Recovery
-----------------------
Activate Web-Recovery by beginning the upgrade Process with a
Firmware-Image from TP-Link. After starting the Firmware Upgrade,
wait ~3 seconds (When update status is switching to 0%), then
disconnect the power supply from the device. Upgrade flag (which
activates Web-Recovery) is written before the OS-image is touched and
removed after write is succesfull, so this procedure should be safe.

Plug the power back in. It will come up in Recovery-Mode on 192.168.0.1.
When active, all LEDs but the WPS LED are off.
Remeber to assign yourself a static IP-address as DHCP is not active in
this mode.

The boot.bin can now be uploaded and flashed using the web-recovery.

Installing via TFTP
-------------------
Prepare an image like following (Filenames from factory image steps
apply here)

 > dd if=/dev/zero of=tp_recovery.bin bs=196608 count=1
 > dd if=tpl.bin of=tmp.bin bs=131584 count=1
 > dd if=tmp.bin of=boot.bin bs=512 skip=1
 > cat boot.bin >> tp_recovery.bin
 > cat owrt.bin >> tp_recovery.bin

Place tp_recovery.bin in root directory of TFTP server and listen on
192.168.0.66/24.

Connect router LAN ports with your computer and power up the router
while pressing the reset button. The router will download the image via
tftp and after ~1 Minute reboot into OpenWRT.

U-Boot CLI
----------
U-Boot CLI can be activated by holding down '4' on bootup.

Dual U-Boot
-----------
This is the first TP-Link MediaTek device to feature a split-uboot
design. The first (factory-uboot) provides recovery via TFTP and HTTP,
jumping straight into the second (firmware-uboot) if no recovery needs
to be performed. The firmware-uboot unpacks and executed the kernel.

Web-Recovery
------------
TP-Link integrated a new Web-Recovery like the one on the Archer C7v4 /
TL-WR1043v5. Stock-firmware sets a flag in the "romfile" partition
before beginning to write and removes it afterwards. If the router boots
with this flag set, bootloader will automatically start Web-recovery and
listens on 192.168.0.1. This way, the vendor-firmware or an OpenWRT
factory image can be written.

By doing the same while performing sysupgrade, we can take advantage of
the Web-recovery in OpenWRT.

It is important to note that Web-Recovery is only based on this flag. It
can't detect e.g. a crashing kernel or other means. Once activated it
won't boot the OS before a recovery action (either via TFTP or HTTP) is
performed. This recovery-mode is indicated by an illuminated WPS-LED on
boot.

Co-authored-by: Julius Schwartzenberg <[email protected]>
Signed-off-by: Renaud Gaspard <[email protected]>
Signed-off-by: Julius Schwartzenberg <[email protected]>
Tested-by: Julius Schwartzenberg <[email protected]>

target/linux/ramips/dts/mt7628an_tplink_archer-c50-v6.dts

@@ -0,0 +1,96 @@
+// SPDX-License-Identifier: GPL-2.0-or-later OR MIT
+
+#include "mt7628an_tplink_8m-split-uboot.dtsi"
+
+/ {
+	compatible = "tplink,archer-c50-v6", "mediatek,mt7628an-soc";
+	model = "TP-Link Archer C50 v6";
+
+	aliases {
+		led-boot = &led_power;
+		led-failsafe = &led_power;
+		led-running = &led_power;
+		led-upgrade = &led_power;
+	};
+
+	keys {
+		compatible = "gpio-keys";
+
+		reset {
+			label = "reset";
+			gpios = <&gpio 38 GPIO_ACTIVE_LOW>;
+			linux,code = <KEY_RESTART>;
+		};
+
+		rfkill {
+			label = "rfkill";
+			gpios = <&gpio 5 GPIO_ACTIVE_LOW>;
+			linux,code = <KEY_RFKILL>;
+		};
+	};
+
+	leds {
+		compatible = "gpio-leds";
+
+		led_power: power {
+			label = "green:power";
+			gpios = <&gpio 11 GPIO_ACTIVE_LOW>;
+		};
+
+		wlan2 {
+			label = "green:wlan2g";
+			gpios = <&gpio 44 GPIO_ACTIVE_LOW>;
+		};
+
+		wlan5 {
+			label = "green:wlan5g";
+			gpios = <&gpio 42 GPIO_ACTIVE_LOW>;
+		};
+
+		lan {
+			label = "green:lan";
+			gpios = <&gpio 41 GPIO_ACTIVE_LOW>;
+		};
+
+		wan {
+			label = "green:wan";
+			gpios = <&gpio 39 GPIO_ACTIVE_LOW>;
+		};
+
+		wan_orange {
+			label = "orange:wan";
+			gpios = <&gpio 40 GPIO_ACTIVE_LOW>;
+		};
+	};
+};
+
+&ehci {
+	status = "disabled";
+};
+
+&ohci {
+	status = "disabled";
+};
+
+&state_default {
+	gpio {
+		groups = "i2c", "p0led_an", "p1led_an", "p2led_an",
+				   "p3led_an", "p4led_an", "wdt", "wled_an";
+		function = "gpio";
+	};
+};
+
+&pcie {
+	status = "okay";
+};
+
+&pcie0 {
+	wifi@0,0 {
+		reg = <0x0000 0 0 0 0>;
+		mediatek,mtd-eeprom = <&radio 0x8000>;
+		ieee80211-freq-limit = <5000000 6000000>;
+		nvmem-cells = <&macaddr_rom_f100>;
+		nvmem-cell-names = "mac-address";
+		mac-address-increment = <(-1)>;
+	};
+};

target/linux/ramips/image/mt76x8.mk

@@ -593,6 +593,20 @@ define Device/tplink_archer-c50-v4
 endef
 TARGET_DEVICES += tplink_archer-c50-v4
 
+define Device/tplink_archer-c50-v6
+  $(Device/tplink-v2)
+  IMAGE_SIZE := 7616k
+  DEVICE_MODEL := Archer C50
+  DEVICE_VARIANT := v6 (EU/RU)
+  TPLINK_FLASHLAYOUT := 8MSUmtk
+  TPLINK_HWID := 0x0C500006
+  TPLINK_HWREVADD := 0x6
+  DEVICE_PACKAGES := kmod-mt7615e kmod-mt7663-firmware-ap
+  IMAGES := sysupgrade.bin
+  SUPPORTED_DEVICES += tplink,c50-v6
+endef
+TARGET_DEVICES += tplink_archer-c50-v6
+
 define Device/tplink_re200-v2
   $(Device/tplink-safeloader)
   IMAGE_SIZE := 7808k

target/linux/ramips/mt76x8/base-files/etc/board.d/01_leds

@@ -76,7 +76,8 @@ tplink,tl-wr850n-v2)
 	ucidef_set_led_switch "wan" "wan" "green:wan" "switch0" "0x01"
 	;;
 tplink,archer-c50-v3|\
-tplink,archer-c50-v4)
+tplink,archer-c50-v4|\
+tplink,archer-c50-v6)
 	ucidef_set_led_switch "lan" "lan" "green:lan" "switch0" "0x1e"
 	ucidef_set_led_switch "wan" "wan" "green:wan" "switch0" "0x01"
 	ucidef_set_led_wlan "wlan2g" "wlan2g" "green:wlan2g" "phy0tpt"

target/linux/ramips/mt76x8/base-files/etc/board.d/02_network

@@ -46,6 +46,7 @@ ramips_setup_interfaces()
 	tplink,archer-c20-v5|\
 	tplink,archer-c50-v3|\
 	tplink,archer-c50-v4|\
+	tplink,archer-c50-v6|\
 	tplink,tl-mr3420-v5|\
 	tplink,tl-wr840n-v4|\
 	tplink,tl-wr840n-v5|\
@@ -294,7 +295,8 @@ ramips_setup_macs()
 		wan_mac=$(macaddr_add "$(mtd_get_mac_binary factory 0xf100)" 1)
 		;;
 	tplink,archer-c20-v5|\
-	tplink,archer-c50-v4)
+	tplink,archer-c50-v4|\
+	tplink,archer-c50-v6)
 		wan_mac=$(macaddr_add "$(mtd_get_mac_binary rom 0xf100)" 1)
 		;;
 	wavlink,wl-wn570ha1|\

target/linux/ramips/mt76x8/base-files/lib/upgrade/platform.sh

@@ -29,7 +29,8 @@ platform_do_upgrade() {
 		default_do_upgrade "$1"
 		;;
 	tplink,archer-c20-v5|\
-	tplink,archer-c50-v4)
+	tplink,archer-c50-v4|\
+	tplink,archer-c50-v6)
 		MTD_ARGS="-t romfile"
 		default_do_upgrade "$1"
 		;;