Power management for ppc 85xx

Hi there!

 

Hope someone out there can give me some pointers here. I've got a 2.6.18
kernel on a ppc 8555, which I configured to enable power management
(CONFIG_PM=y). After doing that, the file /sys/power/state appears on my
file system. If I cat the file I get "standby mem" (without the quotes),
but if I try to write to it (to change the state) I get an EPERM. I
assume it is because I have no code that implements any power save mode
changes, only the interface to change them. Am I wrong? How can I tell
for sure? (the file is writable, so it is not a problem with writing
permissions)

 

So the question is (if I am right) where do I get the code from? I am
hoping someone has implemented power save for that processor already,
but I just don't know where to start looking for that code. Can someone
help? 

 

Thanks very much in advance.

 

Marta Chamorro.