[PPC] Can we do a CPU freq control in a Powerbook G4 with Ubuntu 12.04?

Hi to all,

Do you know if exists any solution to manage CPU freq in a Powerbook G4 with Ubuntu 12.04 (I have Lbuntu)?

I think if it exists, we can better manage the fans and the overall heat of the notebook. Really it seems an airplane reactor when the fans are working doing the simplest thing regarding Mac OS X.

Thanks in advance and sorry about my level of english ;-P