Device Drivers
1 min read
April 2, 2026
Writing Your First Linux Device Driver: A Practical Guide
A step-by-step walkthrough of writing a character device driver for Linux — covering module init, file operations, and talking to hardware registers.
CL
Codewave Labs
Codewave Labs Engineering Team
Device drivers are the bridge between the Linux kernel and your hardware. Whether you are dealing with a simple GPIO expander over I2C or a complex custom FPGA peripheral, the fundamentals are the same.
This guide covers: kernel module boilerplate, the file_operations struct, registering a character device, reading and writing from user space, and handling interrupts. We also show how to use DKMS to keep your out-of-tree module building across kernel updates.
All examples are tested on Linux 6.1 LTS with a Raspberry Pi 4 and a BeagleBone Black.
This guide covers: kernel module boilerplate, the file_operations struct, registering a character device, reading and writing from user space, and handling interrupts. We also show how to use DKMS to keep your out-of-tree module building across kernel updates.
All examples are tested on Linux 6.1 LTS with a Raspberry Pi 4 and a BeagleBone Black.