Answering my own question here...
Travis B. Sawyer wrote:
>Greetings:
>
>We've been using a 2.4.30 kernel (with numerous patches) on a AMCC 440gx
>custom built board for quite some time now.
>
>We're building some new hardware that forces us to go to a 2.6 kernel.
>So, I've downloaded 2.6.16.16 from kernel.org and am porting everything
>forward from our 2.4.30 kernel.
>
>The problem lies in mapping the GPIO regs of the 440 to user space using
>/dev/mem:
>
> gpio_fd = open("/dev/mem", O_RDWR | O_SYNC);
>
> if (0 > gpio_fd) {
> perror("mbGpioGet(): Unable to open gpio");
> return(-1);
> }
>
> addr = (ppc440_gpio_regs_t *)mmap(0, getpagesize() * 2,
> PROT_READ | PROT_WRITE,
> MAP_SHARED, gpio_fd,
> (off_t)(0x40000000));
>
>
>
The above mmap call worked for 2.4.30, but for 2.6.16 I needed to change
the offset
to be a multiple of page size, so:
(off_t)(0x40000000/getpagesize());
-travis
