Book Image

Linux Device Driver Development Cookbook

By : Rodolfo Giometti
Book Image

Linux Device Driver Development Cookbook

By: Rodolfo Giometti

Overview of this book

Linux is a unified kernel that is widely used to develop embedded systems. As Linux has turned out to be one of the most popular operating systems worldwide, the interest in developing proprietary device drivers has also increased. Device drivers play a critical role in how the system performs and ensure that the device works in the manner intended. By exploring several examples on the development of character devices, the technique of managing a device tree, and how to use other kernel internals, such as interrupts, kernel timers, and wait queue, you’ll be able to add proper management for custom peripherals to your embedded system. You’ll begin by installing the Linux kernel and then configuring it. Once you have installed the system, you will learn to use different kernel features and character drivers. You will also cover interrupts in-depth and understand how you can manage them. Later, you will explore the kernel internals required for developing applications. As you approach the concluding chapters, you will learn to implement advanced character drivers and also discover how to write important Linux device drivers. By the end of this book, you will be equipped with the skills you need to write a custom character driver and kernel code according to your requirements.
Table of Contents (14 chapters)
10
Additional Information: Managing Interrupts and Concurrency

Device tree internals

A device tree is a tree data structure with nodes that tell you which devices are currently present in a system along with their configuration settings. Every node has property/value pairs that describe the attributes of the device being represented. Every node has exactly one parent but the root node has no parent.

The next code shows an example representation of a simple device tree that is nearly complete enough to boot a simple operating system, with the platform type, CPU, memory, and a single universal synchronous and asynchronous receiver-transmitter (UART) described with its clocks and interrupt lines. Device nodes are shown with properties and values inside each node.

The device tree syntax is quasi self-explanatory; however, we're going to explain it in detail in this paragraph by taking a look at the simple_platform.dts file from the GitHub...