Source code here.
Books for self-education:
- Linux Device Drivers (J.Corbet, A.Rubini, G.Kroah-Hartman), 2005
- Linux Kernel Development (R.Love), 2010-2013
- Essential Linux Device Drivers (S.Venkataswaran), 2008
- Embedded Linux Driver Development (Th.Petazzoni, M.Opdenacker), 2008
- Brief sysfs Tutorial (B.Marks), 2016
- Linux Kernel Procfs Guide (E.Mouw), 2001
- The Linux Kernel Module Programming Guide (P.J.Salzman, etc),