iTCO_wdt not finding device

Hello!

I cannot get the iTCO_wdt device to be found. I'm not sure how else to troubleshoot at this point, so any help with that is appreciated (i.e. a way to manually check if the device exists or etc.).

I am using Debian 11 on an Intel NUC CMCR1ABB chassis with a CM11EBi716W module. This is an i7 and the watchdog is enabled in the BIOS. I am using the latest BIOS v71. Kernel: 5.10.0-21-amd64 #1 SMP Debian 5.10.162-1 (2023-01-21) x86_64 GNU/Linux.

Every single time I run "modprobe iTCO-wdt" I see in dmesg:

iTCO_vendor_support: vendor-support=0
iTCO_wdt: Intel TCO WatchDog Timer Driver v1.11

And that's it. No device found and no new /dev/watchdog devices or anything new in wdctl.

I have tried:

1. Simply "modprobe iTCO-wdt"

2. Also loading "i2c-i801" and "i2c-smbus" first and then loading the module

3. Blacklisting wdat_wdt and adding nmi_watchdog=0 to GRUB, which correctly caused the existing /dev/watchdog software device to disappear but iTCO_wdt still didn't work

I found one other user with the same issue several years go: https://forums.debian.net/viewtopic.php?t=146358

I'm very certain that this device supports the watchdog, as there is a BIOS option to enable it and Intel has a Windows daemon to make use of it. Is there another Intel watchdog scheme besides iTCO_wdt? Would secureboot lockdown be interfering with this?

Thanks,

Perry