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

Chapter 6: ALSA SoC Framework – Delving into the Machine Class Drivers

While starting our ALSA SoC framework series, we noticed that neither platform nor codec class drivers are intended to work on their own. The ASoC architecture is designed in such a way that platform and codec class drivers must be bound together in order to build the audio device. This binding can be done either from a so-called machine driver or from within the device tree, each of which being machine specific. It then goes without saying that the machine driver targets a specific system, and it may change from one board to another. In this chapter, we highlight the dark side of AsoC machine class drivers and discuss specific cases we may encounter when we need to write a machine class driver.

In this chapter, we will present the Linux ASoC driver architecture and implementation. This chapter will be split into different parts, which are as follows:

  • Introduction to machine class drivers
  • Machine...