mediatek: add support for COMFAST CF-WR632AX

mediatek: add support for COMFAST CF-WR632AX

COMFAST CF-WR632AX is a compact/travel (123.4 mm * 88.7 mm * 34 mm)
wireless WiFi 6 router.

Specification
-------------
- SoC          : MediaTek MT7981B dual-core ARM Cortex-A53 1.3 GHz
- RAM          : DDR3 512 MiB
- Flash        : SPI-NAND 128 MiB (Winbond)
- WLAN         : MediaTek MT7976CN dual-band WiFi 6
  - 2.4 GHz    : b/g/n/ax, MU-MIMO (2x 5 dBi antennas)
  - 5 GHz      : a/n/ac/ax, MU-MIMO (2x 5 dBi antennas)
- Ethernet     :
  - LAN x1     : 10/100/1000 Mbps (MT7981 internal PHY)
  - WAN x1     : 10/100/1000/2500 Mbps (Maxlinear GPY211C)
- USB x1       : 3.0
- UART         : through-hole on PCB
  - assignment : (RX), (TX), (GND), [VCC]
  - settings   : 115200n8
- Buttons x1   : Reset
- LEDs x3      : Status (Blue, Green, Red)
- Fan x1       : PWM, 4-wire, 5 V, 0.3 A, 45 mm * 10 mm
- Power        : 5 VDC, 3 A, Type-C

Flash instructions
------------------
WebUI Method:

1. Install the *squashfs-sysupgrade.bin image using the stock WebUI
   update page.
2. Press and hold the reset button after reboot
   to wipe the stock config.

SSH Method:

1. Import stock firmware settings from backup file
   github.com/andros-ua/owrt-misc/blob/main/cf-wr632ax/backup.file
   Note: WebUI password will be reset to admin1234 after import.
2. Connect via SSH using root:openwrt credentials.
3. Upload the *squashfs-sysupgrade.bin image.
4. Use the command: sysupgrade -n
   All checks should pass.

Return to stock
---------------
Flash a stock firmware
using the OpenWrt sysupgrade method.

Recovery
--------
Power on the router while holding the Reset button until
the LED flashes 5 times.
The U-Boot Flash WebUI will be available at http://192.168.1.1
or
Connect UART and use the U-Boot menu to flash the firmware image
or boot an OpenWrt initramfs image.

OpenWrt U-Boot flash instructions
---------------------------------
1. Flash ordinary OpenWrt image.
2. Login into the device and backup everything, especially 'Factory' part.
3. Unlock mtd partitions:
    apk add kmod-mtd-rw
    insmod mtd-rw i_want_a_brick=1
4. Write new BL2 and FIP:
    mtd write openwrt-mediatek-filogic-comfast_cf-wr632ax-ubootmod-preloader.bin BL2
    mtd write openwrt-mediatek-filogic-comfast_cf-wr632ax-ubootmod-bl31-uboot.fip FIP
5. Set static IP on your PC:
    ip 192.168.1.254 mask 255.255.255.0
6. Serve OpenWrt initramfs image using TFTP server.
7. Reboot device, wait for TFTP recovery to complete.
8. After OpenWrt has booted, perform sysupgrade.

MAC Addresses:
----------------------------------------------------------
| Interface    |  MAC              | Source              |
---------------|-------------------|----------------------
| WAN (label)  | 40:A5:EF:xx:xx:xx | Factory, 0xe000     |
| LAN          | 40:A5:EF:xx:xx:xx | Factory, 0xe000 + 1 |
| WLAN 2.4 GHz | 40:A5:EF:xx:xx:xx | Factory, 0x4        |
| WLAN 5 GHz   | 40:A5:EF:xx:xx:xx | Factory, 0x8000     |
----------------------------------------------------------

Signed-off-by: Andrii Kuiukoff <[email protected]>
Link: https://github.com/openwrt/openwrt/pull/20382
Signed-off-by: Hauke Mehrtens <[email protected]>