Adding devices to ...system/cpu/cpuX/cpufreq from other modules

Hi developers,

I'm working on a specialiced version of powernow-k8 for phenom processors here. On these cpu's it is possible to modify the multis and voltages for the p-states by changing the associated msr registers. First i stripped down powernow-k8 and removed all the <k10 stuff. Then i modified the initialisation function to use the p-state msr registers and not the acpi tables to populate the cpufreq table. I also had to change the acpi table to use higher that stock multis. Currently i use a separate module to modify the msr registers. It uses it's own substyem and has devices for each vid did and fid of each cores p-states.
I'd like to move this functionality into my powernow module but since i'm new to kernel coding i don't know how to add the devices to /sys/devices/system/cpu/cpu0/cpufreq. I'd be glad if someone can post a small code snippet or a reference to an module which does this.

greets
achim~