You're reading from Linux Device Driver Development Everything you need to start with device driver development for Linux kernel and embedded Linux

Product type Paperback

Published in Apr 2022

Publisher Packt

ISBN-13 9781803240060

Length 708 pages

Edition 2nd Edition

Languages

C++

Tools

Linux

Concepts

Embedded Systems

Author (1):

John Madieu

View More author details

Table of Contents (23) Chapters

Preface

1. Section 1 -Linux Kernel Development Basics

2. Chapter 1: Introduction to Kernel Development FREE CHAPTER

3. Chapter 2: Understanding Linux Kernel Module Basic Concepts

4. Chapter 3: Dealing with Kernel Core Helpers

5. Chapter 4: Writing Character Device Drivers

6. Section 2 - Linux Kernel Platform Abstraction and Device Drivers

7. Chapter 5: Understanding and Leveraging the Device Tree

8. Chapter 6: Introduction to Devices, Drivers, and Platform Abstraction

9. Chapter 7: Understanding the Concept of Platform Devices and Drivers

10. Chapter 8: Writing I2C Device Drivers

11. Chapter 9: Writing SPI Device Drivers

12. Section 3 - Making the Most out of Your Hardware

13. Chapter 10: Understanding the Linux Kernel Memory Allocation

14. Chapter 11: Implementing Direct Memory Access (DMA) Support

15. Chapter 12: Abstracting Memory Access – Introduction to the Regmap API: a Register Map Abstraction

16. Chapter 13: Demystifying the Kernel IRQ Framework

17. Chapter 14: Introduction to the Linux Device Model

18. Section 4 - Misc Kernel Subsystems for the Embedded World

19. Chapter 15: Digging into the IIO Framework

20. Chapter 16: Getting the Most Out of the Pin Controller and GPIO Subsystems

21. Chapter 17: Leveraging the Linux Kernel Input Subsystem

22. Other Books You May Enjoy

Learning how not to write GPIO client drivers

There are situations where writing user space code would achieve the same goals as writing kernel drivers. Moreover, the GPIO framework is one of the most used frameworks in the user space. It then goes without saying that there are several possibilities to deal with it in the user space, some of which we will introduce in this chapter.

Goodbye to the legacy GPIO sysfs interface

Sysfs has ruled GPIO management from the user space for quite a long time now. Though it is scheduled for removal, the sysfs GPIO interface still has a few days ahead of it. CONFIG_GPIO_SYSFS can still enable it, but its use is discouraged, and it will be removed from mainline Linux. This interface allows managing and controlling GPIOs through a set of files. It is located at /sys/class/gpio/, and the following are the common directory paths and attributes that are involved: