leds.c

嵌入式linux（2.6）+ARM（s3c2410）下的leds驱动程序

#include <linux/config.h> 
#include <linux/module.h> 
#include <linux/kernel.h> 
#include <linux/init.h> 
 
#include <linux/miscdevice.h> 
#include <linux/sched.h> 
#include <linux/delay.h> 
#include <linux/poll.h> 
#include <linux/spinlock.h> 
#include <linux/delay.h> 
 
#include <asm/hardware.h> 
#include <asm/arch/regs-gpio.h> 
#include <linux/device.h> 
#include <linux/devfs_fs_kernel.h> 
#include <linux/types.h> 
#include <linux/cdev.h> 
#include <linux/errno.h> 
#include <asm/uaccess.h> 
 
#define DEVICE_NAME "led" 
#define LED_MAJOR 233 
 
MODULE_AUTHOR("huangweijun"); 
MODULE_LICENSE("Dual BSD/GPL"); 
MODULE_ALIAS("the first char device driver"); 
 
static unsigned long led_table [] = { 
	S3C2410_GPB7, 
	S3C2410_GPB8, 
	S3C2410_GPB9, 
	S3C2410_GPB10, 
        S3C2410_GPB7_OUTP, 
        S3C2410_GPB8_OUTP, 
        S3C2410_GPB9_OUTP, 
        S3C2410_GPB10_OUTP, 
}; 
 
 
static int leds_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) 
{ 
	switch(cmd) { 
		case 0: 
		case 1: 
			if (arg > 3) { 
				return -EINVAL; 
			} 
			s3c2410_gpio_setpin(led_table[arg],!cmd); 
		break; 
        	default: 
			return -EINVAL; 
	} 
    return 0; 
} 
 
static struct file_operations leds_fops = { 
	.owner = THIS_MODULE, 
	.ioctl = leds_ioctl, 
}; 
 
static struct class *led_class; 
 
static int __init leds_init(void) 
{ 
  	int err = 0; 
    int i;   
           
    if(register_chrdev(LED_MAJOR,"led",&leds_fops)){ 
       printk("led driver:Unable to register driver\n"); 
       return -ENODEV; 
    } 
          
    led_class = class_create(THIS_MODULE, "led"); 
    if(IS_ERR(led_class)){ 
       err = PTR_ERR(led_class); 
       goto out_chrdev; 
    } 
    class_device_create(led_class,MKDEV(LED_MAJOR, 0),NULL,"led"); 
           
    err = devfs_mk_cdev(MKDEV(LED_MAJOR,0),S_IFCHR | S_IRUGO | S_IWUSR,"led"); 
    if(err) 
       goto out_class; 
 
    for(i=0;i<4;i++){ 
        s3c2410_gpio_cfgpin(led_table[i],led_table[i+4]); 
        s3c2410_gpio_setpin(led_table[i],1); 
    } 
  	printk("led driver initialized\n"); 
  	goto out; 
 
out_class: 
    class_device_destroy(led_class,MKDEV(LED_MAJOR, 0)); 
    class_destroy(led_class); 
out_chrdev: 
    unregister_chrdev(LED_MAJOR, "led"); 
out: 
    return err; 
} 
 
static void __exit leds_exit(void) 
{ 
	class_device_destroy(led_class,MKDEV(LED_MAJOR,0)); 
	class_destroy(led_class); 
	unregister_chrdev(LED_MAJOR,"led"); 
	devfs_remove("led"); 
	printk("led driver removed\n"); 
} 
 
module_init(leds_init); 
module_exit(leds_exit);