Writing LED drivers

1, create the LED drive device files:

(1) Initialize the Cdev with the cdev-init function

(2) Specify the device number

There are two ways to assign a device number: Specify it directly in your code (hard-coded)

Dynamic allocation

(3) using the cdev-add function to add a character device to a character device array in the kernel

(4) Create a struct class using the class-creat Macro

(5) Create a device file using the device-create function

2, led Drive in two ways to control the led

Controlling LEDs with strings

LED via I/O command

3, a complete linux driver mainly consists of internal processing and hardware interaction with two parts.

Inux Drive is also the main processing of these two parts in different platforms; porting in different Linux kernel versions mainly deals with the first part (internal processing); porting on different hardware platforms is primarily about dealing with the second part (interacting with the hardware).

Writing LED drivers