I am terrified by existance of the userland gpio interface, basically the concept that users should be able to change some pin is more than suspect, it is crazy. It completely violates the Unix principle of mapping hardware support to narrow device catagories on a functional basis, which only the right user can use.
The pins a user will change are usually undocumented. They could be wired to a bomb. If these drivers only exposed pins which had *known function*, or which are known to be otherwise unused (a pin on a header), that would be fine. But that's not how it plays out usually.
