Linux Driver Tutorial

Here you can find examples for simple Linux Kernel Modules and Linux Drivers.

Preparation

I used a Raspberry Pi 3 to develop and test my modules and drivers. To compile them, you need to install the Kernel headers on your Pi. On Raspberry Pi OS you can do this with the following command:

sudo apt update && sudo apt upgrade -y
sudo apt install raspberrypi-kernel-headers
reboot

Raspberry Pi OS is only installs the latest kernel headers. So, make sure, you are running the latest kernel.

You also need the build utils (make, gcc, ...) but they come preinstalled on Raspberry Pi OS.

Content

In this repo you can find examples for:

1. Simple Hello World Kernel Module
2. An improved Hello World Linux Kernel Module
3. An example for using GPIOs in a driver without device tree
4. Some info about Device Files, Device Numbers, Block and Character Devices
5. Create a Character Device in a Driver
6. Linux Kernel log levels
7. Implement open and release functions for character devices
8. Implement read and write functions for character devices
9. Create a Character Device in a Driver manually
10. Automatically create a Device File within the driver
11. Dynamical memory allocation and private data in the struct file
12. First introduction to ioctl
13. Implementing ioctl properly
14. The device tree
15. Adding a device over the device tree
16. A Device Tree Device Driver
17. Parsing parameters of a Device Tree Device Driver
18. Writing to the kernel's log with device information
19. Using GPIOs in a Device Tree Device Driver
20. Allocating and using device data
21. Miscellaneous devices for easy device files
22. Adding a misc device to the platform device driver

More Information

For more information about my Linux Driver examples check out my videos and my playlist

Support me

If you want to support me, you can buy me a coffee buymeacoffee.com/johannes4linux.