4leds.c

该程序是在S3C2410基础上开发的Linux流水灯驱动程序

#include <linux/kernel.h>
#include <linux/module.h>
//#include <linux/fs.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/timer.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/devfs_fs_kernel.h>       //增加一条2.6内核下的头文件,以支持文件系统;对于devfs_mk_cdev重要
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/hardware.h>
#include <asm/arch-s3c2410/map.h>
#include <asm/arch-s3c2410/regs-gpio.h>

#define LED_ON 0
#define LED_OFF 1
#define DEVICE_NAME "IO"
//#define IO_MAJOR 0
#define IO_MINOR 1              //次设备号
static int IO_MAJOR = 0;

int IO_ioctl(struct inode *inode, struct file *flip, unsigned int cmd,unsigned long arg)
{
  __raw_writel(cmd,S3C2410_GPFDAT);
  return 0;
}

int IO_open(struct inode *inode, struct file *flip)
{
 // __raw_writel(0x5500,S3C2410_GPFCON);
 // __raw_writel(0xf0,S3C2410_GPFUP);
 // __raw_writel(0x00,S3C2410_GPFDAT);

  printk( "IO device opened\n");
   return 0;  
}

int IO_release(struct inode *inode, struct file *flip)
{
  printk("IO device closed \n");
  return 0;
}

struct file_operations IO_fops=
{
  .owner    = THIS_MODULE,
  .open     = IO_open,
  .ioctl    = IO_ioctl,
  .release  = IO_release,
};

int IO_init(void)
{
  int ret;
  __raw_writel(0x5500,S3C2410_GPFCON);
  __raw_writel(0xf0,S3C2410_GPFUP);
  __raw_writel(0x00,S3C2410_GPFDAT);
  //printk(DEVICE_NAME":init OK \n");
  ret = register_chrdev(IO_MAJOR, DEVICE_NAME, &IO_fops);
  if(ret<0)
    { printk(DEVICE_NAME " can't get major number\n");
	  return ret;
	}
  IO_MAJOR = ret; 
  devfs_mk_cdev(MKDEV(IO_MAJOR,IO_MINOR),S_IFCHR | S_IRUSR | S_IWUSR|S_IRGRP,"IO/0"); //devfs_mk_cdev创建设备节点
  printk(DEVICE_NAME":init OK\n");
  return 0;
}

void IO_exit(void)
{
  printk("call IO_exit \n");
  unregister_chrdev(IO_MAJOR,DEVICE_NAME);
}

module_init(IO_init);
module_exit(IO_exit);
MODULE_LICENSE("Dual BSD/GPL");