
Linus Torvalds
included patches into the mainline tree which implement a stable userspace driver API into the Linux kernel. The stable driver API was already announced
a year ago by Greg Kroah-Hartman. Now the
last patches were uploaded and the API was
included in Linus' tree. The idea of the API is to make life easier for driver developers:
"This interface allows the ability to write the majority of a driver in userspace with only a very small shell of a driver in the kernel itself. It uses a char device and sysfs to interact with a userspace process to process interrupts and control memory accesses."