Can hardware registers be mapped to userspace

Question

I'm developing an LED driver on Freescale MPC8306. In driver code, I do ioremap on GPIO registers and call remap_pfn_range upon the remapped GPIO register address, then, call mmap in userspace to map the GPIO register to userspace. I haven't done this before and I want to know if this method work or not. Can some help me? Thanks in Advance.

Answer 1

An easier way would probably just to mmap the relevant offset of /dev/mem in your userspace program directly. This allows you to access the physical memory layout by seeking into it.

AFAIK, this is what the RaspberryPi developers have done to make GPIO memory mapped I/O registers available to userspace programs.

Answer 2

You should be using /dev/mem interface for accessing the GPIO registers. A good reference for controlling LEDs via GPIOs on another embedded board is given here.