A quick update - I was finally able to retrieve all needed data from fglrx (via
some ADL SDK overdrive6 tinkering). It seems there is a lot of work (e.g. there
is a feature for setting series of pairs temperature<->fanspeed), but at least
I figured out the purpose of used registers and data values (I hope).

So I'll try to come up with basic functionality and hwmon interface this week.