Hi NSA,
Thanks a lot!
I read the great link!
Oh regarding what you said, I think it's the opposite, i.e. the BASE Address of the GPIO (which can be read in datasheet) is the physical address, while the Address returned from mmap is the virtual address.
I have two question please.
1. When I access the Virtual File System (VFS) of GPIO1_15, I did not disable the interface clock, and the GPIO1_15 indeed turned off and on the leg as I instructed.
Was it a "coincidence", i.e. the GPIO wa already configured to OUT, or does the VFS take care of that for you?
2. I think that when writing directly to GPIO, you need to first disable the Interface clock ---> Then change the settings ---> then enable the Interface Clock, right?