On Tue, 2007-10-16 at 23:21 -0700, Jeff Mock wrote: > David Hawkins wrote: > >> I have a PPC440EPx Sequoia Evaluation board that runs on Linux 2.6.21. > >> What I would want to do is to control (write and read values to) its > >> GPIO. Perhaps similar to Turbo C's outputb(0x378,0x01) to write and > >> inportb(0x378) to read. I read the PPC440EPx manual but I find it > >> difficult to understand. > >> > >> Could anyone show me any tutorial or some sample codes? > > > > I copied the code below from some test code I wrote for a TS7300 > > board (uses an ARM EP9302 processor). However, since its user-space > > code it should work fine. > > > > I might be a little out of date, but I think you must write your own > driver to wiggle the GPIO pins on a 440 processor. I just finished a > project using a 440GX with a 2.6.15 kernel (we froze the code about 8 > months ago). > > The 440 powerPC core is a 32-bit processor with 36-bit physical > addresses. The physical address for the GPIO pins is someplace above > 4GB. An mmap() of /dev/mem only lets you map the lower 4GB of the > address space, as a result you can't write a user space program on the > 440 to wiggle the GPIO pins. (This was true with 2.6.15, I can't speak > for later kernels).
This depends on the 440 chip itself. If I recall correctly, the 440EP(x) chips don't have I/O above 4GB. josh _______________________________________________ Linuxppc-embedded mailing list Linuxppc-embedded@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-embedded
