How old Linux Device Drivers 3 book is now?

Hi everyone. I'm a totally fresh and newbie with kernel development and I've started reading Linux Device Drivers 3 book (CORBET et al). Since this book approaches is based on kernel 2.6 and we are currently with kernel 4.x, someone could help me telling if this book is still a good introduction to the subject, or is now highly outdated? Thanks in advance. -- Fernando França http://desconstruindo.eng.br Linux user #263682 Dificultando a vida dos usuários desde 1999