Hi,
The AD5362 driver was added in the v3.2 release of the Linux kernel and the AD7606 driver was added in the v2.6.39 release. If you want to use the drivers with an earlier version of the Linux kernel you'll have to backport the drivers to the earlier version.
In the documentation for the AD7606 driver and the AD5362 driver you can find examples on how to access the devices from userspace.
- Lars