Book Image

Linux Device Drivers Development

By : John Madieu
Book Image

Linux Device Drivers Development

By: John Madieu

Overview of this book

Linux kernel is a complex, portable, modular and widely used piece of software, running on around 80% of servers and embedded systems in more than half of devices throughout the World. Device drivers play a critical role in how well a Linux system performs. As Linux has turned out to be one of the most popular operating systems used, the interest in developing proprietary device drivers is also increasing steadily. This book will initially help you understand the basics of drivers as well as prepare for the long journey through the Linux Kernel. This book then covers drivers development based on various Linux subsystems such as memory management, PWM, RTC, IIO, IRQ management, and so on. The book also offers a practical approach on direct memory access and network device drivers. By the end of this book, you will be comfortable with the concept of device driver development and will be in a position to write any device driver from scratch using the latest kernel version (v4.13 at the time of writing this book).
Table of Contents (23 chapters)
Free Chapter
1
Introduction to Kernel Development

IIO Framework

Industrial I/O (IIO) is a kernel subsystem dedicated to analog-to-digital converters (ADC) and digital-to-analog converters (DAC). With the growing number of sensors (measurement devices with analogue to digital, or digital to analogue, capabilities) with different code implementations scattered over the kernel sources, gathering them became necessary. This is what the IIO framework does, in a generic and homogeneous way. Jonathan Cameron and the Linux IIO community have been developing it since 2009.

Accelerometers, gyroscopes, current/voltage measurement chips, light sensors, pressure sensors, and so on all fall into the IIO family of devices.

The IIO model is based on a device and channel architecture:

  • Device represents the chip itself. It is the top level of the hierarchy.
  • Channel represents a single acquisition line of the device. A device may have one...