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

Platform devices

Actually, we should have said pseudo platform device, since this section concerns devices that sit on pseudo platform buses. When you are done with the driver, you will have to feed the kernel with devices needing that driver. A platform device is represented in the kernel as an instance of struct platform_device, and looks as follows:

struct platform_device { 
   const char *name; 
   u32 id; 
   struct device dev; 
   u32 num_resources; 
   struct resource *resource; 
}; 

When it comes to the platform driver, before driver and device match, the name field of both struct platform_device and static struct platform_driver.driver.name must be the same. The num_resources and struct resource *resource field will be covered in the next section. Just remember that, since resource is an array, num_resources must contain the size of that array.

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