The easiest way would be via serial debugging cable and a few dprintf()s in the driver.
Unfortunetly not only do i not have a serial cable, but theres no serial port on the laptop... :(.
If you don't have that, you could write output to a file, and do a open /write/close/sync for every line you put in there.
Do you mean using the standard C FileI/O functions? I just tried this anyway (Messing around) and i'm getting 'undefined reference...'. Is this because a driver is a kernel-module where these functions don't belong?
I think my noobness is showing again :O. Sorry.
-- Thank You Mathew Schofield mr.skoe@xxxxxxxxx
