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Linux Device Driver Development

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

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Product type Paperback
Published in Apr 2022
Publisher Packt
ISBN-13 9781803240060
Length 708 pages
Edition 2nd Edition
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John Madieu John Madieu
Author Profile Icon John Madieu
John Madieu
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Toc

Table of Contents (23) Chapters Close

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

Getting deeper inside LDM

So far, we have discussed buses, drivers, and devices, which were used to build the system device topology. While this is true, the previous topics were the tip of the iceberg. Under the hood, LDM relies on the three lowest level data structures, which are kobject, kobj_type, and kset. These are used to link the objects.

Before we go any further, let's define some of the terms that will be used throughout this chapter:

  • sysfs: sysfs is an in-memory virtual filesystem that shows the hierarchy of kernel objects, abstracted by instances of struct kobject.
  • Attribute: An attribute (or sysfs attribute) appears as a file in sysfs. From within the kernel, it can be mapped to anything: a variable, a device property, a buffer, or anything useful to the driver that may need to be exported to the world.

In this section, we will learn how each of these structures is involved in the device model.

Understanding the kobject structure

struct...

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