Hi I want to use the wdat_wdt to support a watchdog of SIONCT (a multi-function device (mfd)), and I register instructions for wdat_wdt in BIOS, it need registers 0x2e-0x2f to access the watchdog, then register 0x2e-0x2f will be forever occupied by platform device wdat_wdt, see the code: https://elixir.bootlin.com/linux/v6.6-rc5/source/drivers/acpi/acpi_watchdog.c#L180 but the 0x2e-0x2f are special, they are used for a multi-function device --SIONCT, the device have many pins can not only support features for watchdog, but also other features like leds, fans, temperature monitor... there are drivers for these pins, e.g. gpio-f7188x, nct6775, w83627hf... these driver use the shared register 0x2e-0x2f. So the issue happened, the wdat_wdt occupied the shared register 0x2e-0x2f, then the other driver can not load. Here is the msg I collected from my device: root@ipc-SIMATIC-IPC-BX-21A:/home/ipc# cat /proc/ioports 0000-0cf7 : PCI Bus 0000:00 0000-001f : dma1 0020-0021 : pic1 002e-002e : wdat_wdt 002f-002f : wdat_wdt It will cause other SIONCT drivers can not load, e.g. root@ipc-SIMATIC-IPC-BX-21A:/home/ipc# modprobe gpio-f7188x modprobe: ERROR: could not insert 'gpio_f7188x': No such device And dmesg info is: [ 213.559168] gpio-f7188xI/O address 0x002e already in use Same reason for other drivers: root@ipc-SIMATIC-IPC-BX-21A:/home/ipc# modprobe nct6775 modprobe: ERROR: could not insert 'nct6775': No such device Do you have any idea for the wdat_wdt to add support for multi-function device? BRS Xing Tong Wu
