I'm brand new to linux kernel. I just want to know how to call the function which is defined in kernel source.

I use TI's omap3530 with ARM cortex A8. I'm trying to use CPU frequency scaling function which was defined in kernel directory "arch/arm/plat-omap/omap-pm-noop.c" from userspace (under linux OS), in order to set the clock rate to what I want. I know that I can probably use it to do my work but I just don't know how to call it from OS. Neither do I know which files to include.

Can Anyone help me with it? Thanks in advance.

You'll probably want to Google for: linux "system calls"

Thanks. I searched for it, but I still have no idea. Can you give me some detail information about how to call function under a particular directory under kernel source?

Thanks!