Book Image

Mastering Linux Device Driver Development

By : John Madieu
Book Image

Mastering Linux Device Driver Development

By: John Madieu

Overview of this book

Linux is one of the fastest-growing operating systems around the world, and in the last few years, the Linux kernel has evolved significantly to support a wide variety of embedded devices with its improved subsystems and a range of new features. With this book, you’ll find out how you can enhance your skills to write custom device drivers for your Linux operating system. Mastering Linux Device Driver Development provides complete coverage of kernel topics, including video and audio frameworks, that usually go unaddressed. You’ll work with some of the most complex and impactful Linux kernel frameworks, such as PCI, ALSA for SoC, and Video4Linux2, and discover expert tips and best practices along the way. In addition to this, you’ll understand how to make the most of frameworks such as NVMEM and Watchdog. Once you’ve got to grips with Linux kernel helpers, you’ll advance to working with special device types such as Multi-Function Devices (MFD) followed by video and audio device drivers. By the end of this book, you’ll be able to write feature-rich device drivers and integrate them with some of the most complex Linux kernel frameworks, including V4L2 and ALSA for SoC.
Table of Contents (19 chapters)
1
Section 1:Kernel Core Frameworks for Embedded Device Driver Development
6
Section 2: Multimedia and Power Saving in Embedded Linux Systems
13
Section 3: Staying Up to Date with Other Linux Kernel Subsystems

Understanding the Linux kernel release process

According to the Linux kernel release model, there are always three types of active kernel release: mainline, the stable release, and the Long-Term Support (LTS) release. First, bug fixes and new features are gathered and prepared by subsystem maintainers and then submitted to Linus Torvalds in order for him to include them in his own Linux tree, which is called the mainline Linux tree, also known as the master Git repository. This is where every stable release originates from.

Before each new kernel version is released, it is submitted to the community through release candidate tags, so that developers can test and polish all the new features and, most importantly, share feedback. During this cycle, Linus will rely on the feedback in order to decide whether the final version is ready to be released. When he is convinced that the new kernel is ready to go, he makes (tags it actually) the final release, and we call this release stable...