Linux Driver Development

Drivers may be built into the kernel (=y) or as modules (=m).

A new driver normally requires:

Kconfig
Makefile
driver source
Device Tree binding
board node

Common Device Tree properties include compatible, reg, interrupts, clocks, resets, pinctrl, GPIOs, and status.

m kernel
find out -name '*.ko'
insmod demo.ko
dmesg | tail
rmmod demo

Prefer standard kernel subsystems such as V4L2, ALSA, Input, IIO, GPIO, PWM, and networking over private character-device interfaces.