You're reading from Mastering Linux Device Driver Development Write custom device drivers to support computer peripherals in Linux operating systems

Product type Paperback

Published in Jan 2021

Publisher Packt

ISBN-13 9781789342048

Length 646 pages

Edition 1st Edition

Languages

C++

Tools

Linux

Concepts

Embedded Systems

Author (1):

John Madieu

View More author details

Table of Contents (19) Chapters

Preface

1. Section 1:Kernel Core Frameworks for Embedded Device Driver Development

2. Chapter 1: Linux Kernel Concepts for Embedded Developers FREE CHAPTER

3. Chapter 2: Leveraging the Regmap API and Simplifying the Code

4. Chapter 3: Delving into the MFD Subsystem and Syscon API

5. Chapter 4: Storming the Common Clock Framework

6. Section 2: Multimedia and Power Saving in Embedded Linux Systems

7. Chapter 5: ALSA SoC Framework – Leveraging Codec and Platform Class Drivers

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

9. Chapter 7: Demystifying V4L2 and Video Capture Device Drivers

10. Chapter 8: Integrating with V4L2 Async and Media Controller Frameworks

11. Chapter 9:Leveraging the V4L2 API from the User Space

12. Chapter 10: Linux Kernel Power Management

13. Section 3: Staying Up to Date with Other Linux Kernel Subsystems

14. Chapter 11: Writing PCI Device Drivers

15. Chapter 12: Leveraging the NVMEM Framework

16. Chapter 13: Watchdog Device Drivers

17. Chapter 14: Linux Kernel Debugging Tips and Best Practices

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Introduction to regmap and its data structures – I2C, SPI, and MMIO

Regmap is an abstraction register access mechanism provided by the Linux kernel that mainly targets SPI, I2C, and memory-mapped registers.

APIs in this framework are bus agnostic and handle the underlying configuration under the hood. That being said, the main data structure in this framework is struct regmap_config, defined in include/linux/regmap.h in the kernel source tree as follows:

struct regmap_config {
   const char *name;
   int reg_bits;
   int reg_stride;
   int pad_bits;
   int val_bits;
   bool (*writeable_reg)(struct device *dev, unsigned int reg);
   bool (*readable_reg)(struct device *dev, unsigned int reg);
   bool (*volatile_reg)(struct device *dev, unsigned int reg);
   bool (*precious_reg)(struct device *dev, unsigned int reg);
   int...