Inside a char driver

Char device looks like a stream of bytes, just like a regular UNIX file. In a nut shell, a char device is a bunch of functions that support standrad UNIX file operations.

open
release
Exclusive access. Module usage count.
read
write
Read/write byte stream via read()/write().
read_proc
write_proc
Custom features via /proc entry.
ioctl
Custom features via ioctl().
init
exit