Linux LED driver test source code

Linux LED driver test source code-Linux general technology-Linux programming and kernel information, the following is a detailed description. // ■

// [Copyright] Copyright (c) 2006-2008 GLIETHTTP

//

// [File version] v1.x

//

// [Creation date] 2006/12/21

//

// [Description] LED flashlight drive test-led_driver.c

// ■

# Ifndef _ KERNEL __

# Define _ KERNEL __

# Endif

# Ifndef MODULE

# Define MODULE

# Endif

# Include

# Include

# Include

# Include

# Include

# Include /* Printk ()*/

# Include /* Kmalloc ()*/

# Include /* Everything ...*/

# Include /* Error codes */

# Include /* Size_t */

# Include /* O_ACCMODE */

# Include /* COPY_TO_USER */

# Include/* cli (), * _ flags */

# Include



# Include "led_driver.h"



# Define DEVICE_NAME "led"

# Define led_MAJOR 254

# Define led_MINOR 0



# Define DBG (x...) printk (DEVICE_NAME ":" x)

//

Static int led_ioctl (struct inode * inode, struct file * file, unsigned int cmd, unsigned long arg)

{

Switch (cmd)

{

Case 1: xledbench on (); break;

Case 2: xledshortoff (); break;

Case 3: xLED2_ON (); break;

Case 4: xLED2_OFF (); break;

Default: DBG ("error cmd number \ n"); break;

}

Return 0;

}

//

Static int led_open (struct inode * inode, struct file * file)

{

MOD_INC_USE_COUNT;

Xledbench on ();

DBG ("device open sucess! \ N ");

Return 0;

}

//

Static int led_release (struct inode * inode, struct file * filp)

{

MOD_DEC_USE_COUNT;

Xled0000off ();

DBG ("device release \ n ");

Return 0;

}

//

Static struct file_operations led_fops = {

Owner: THIS_MODULE,

Ioctl: led_ioctl,

Open: led_open,

Release: led_release,

};

//

Static int _ init led_init (void)

{Int result;

SET_MODULE_OWNER (& led_fops );

Result = register_chrdev (led_MAJOR, "led", & led_fops );

If (result <0) return result;

DBG ("initialized \ n ");

XLED_Install ();

Return 0;

}

//

Static void _ exit led_exit (void)

{

Unregister_chrdev (led_MAJOR, "led ");

DBG ("unloaded \ n ");

}

//

Module_init (led_init );

Module_exit (led_exit );

MODULE_LICENSE ("GPL ");

MODULE_AUTHOR ("gliethttp ");

MODULE_DESCRIPTION ("led driver test! ");


Compile:

[Root @ gliethttp] # arm-linux-gcc-c-I my_linux_head_dir led_driver.c

After compilation, an led_driver.o file is generated, and led_driver.o is sent to the target board through the rz three-line serial port, and a device node is created on the target board.

[Root@ B .J.xx/root] # mknod/dev/led c 254 0

Then install the driver

[Root@ B .J.xx/root] # insmod led_driver.o

You can use lsmod to query the driver module.

[Root@ B .J.xx/root] # lsmod

Uninstall the driver through rmmod

# Rmmod led_driver [root@ B .J.xx/root]


After the driver is installed, when the application calls fd = open ("/dev/led", O_RDWR), the LED indicator on the Development Board will light up. When the application calls close (fd) the LED on the Development Board is off.