on the 2835. Calling mmap(/dev/gpiomem) will map the GPIO
register page to the user's pointer.
+config BCM2835_SMI_DEV
+ tristate "Character device driver for BCM2835 Secondary Memory Interface"
+ depends on BCM2835_SMI
+ default m
+ help
+ This driver provides a character device interface (ioctl + read/write) to
+ Broadcom's Secondary Memory interface. The low-level functionality is provided
+ by the SMI driver itself.