Book Image

Linux Device Drivers Development

By : John Madieu
Book Image

Linux Device Drivers Development

By: John Madieu

Overview of this book

Linux kernel is a complex, portable, modular and widely used piece of software, running on around 80% of servers and embedded systems in more than half of devices throughout the World. Device drivers play a critical role in how well a Linux system performs. As Linux has turned out to be one of the most popular operating systems used, the interest in developing proprietary device drivers is also increasing steadily. This book will initially help you understand the basics of drivers as well as prepare for the long journey through the Linux Kernel. This book then covers drivers development based on various Linux subsystems such as memory management, PWM, RTC, IIO, IRQ management, and so on. The book also offers a practical approach on direct memory access and network device drivers. By the end of this book, you will be comfortable with the concept of device driver development and will be in a position to write any device driver from scratch using the latest kernel version (v4.13 at the time of writing this book).
Table of Contents (23 chapters)
Free Chapter
1
Introduction to Kernel Development

Deep inside LDM

Under the hood, the LDM relies on three important structures, which are kobject, kobj_type, and kset. Let us see how each of these structures are involved in the device model.

kobject structure

kobject is the core of the device model, running behind the scenes. It brings an OO-like programming style to the kernel, and is mainly used for reference counting and to expose devices hierarchies and relationships between them. kobjects introduce the concept of encapsulation of common object properties, such as usage reference counts:

struct kobject { 
    const char *name; 
    struct list_head entry; 
    struct kobject *parent; 
    struct kset *kset; 
    struct kobj_type *ktype; 
    struct sysfs_dirent *sd; ...