Writing device drivers to control new hardware can be hard work. Chris Simmonds, speaking at Embedded World 2016, explains how to take the easy road by writing userspace drivers.
Slides: http://2net.co.uk/slides/ew2016-userspace-drivers-slides.pdf
Paper: http://2net.co.uk/slides/ew2016-userspace-drivers-paper.pdf
Sample code: http://2net.co.uk/downloads/ew2016-demos.tar.gz