zjdev.c

在Linux下实现文件的拷贝

#ifndef __KERNEL__
#define __KERNEL__ 
#endif

#ifndef MODULE
#define MODULE     
#endif

#include </home/zhangjian/ostask/linux-2.6.18/include/asm/module.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <asm/uaccess.h>
#include <asm/io.h>

#define CHAR_MAJOR_NUM 300	
#define OPENSPK 1
#define CLOSESPK 2
#define DEVICE_NAME "zjdev"

//static int test_major=0;
static int device_open=0;
//static char message[]="This is from device driver!";
static int dev_open(struct inode *, struct file *);
static int dev_release(struct inode *, struct file *);
static ssize_t dev_read(struct inode *, struct file *, char *,unsigned long );
static ssize_t dev_write(struct file *, const char *, size_t, loff_t *);
//static int dev_ioctl(struct inode *,struct file *,unsigned int ,unsigned int ); 
char *message_ptr;

struct file_operations dev_fops =
{          
	 open: dev_open,
	 release: dev_release,
  	 read: dev_read,
    write: dev_write,
};

 int dev_init(void)
{
  
	int result;
   result=register_chrdev(CHAR_MAJOR_NUM, "zjdev", &dev_fops); 
   if (result)
		printk("mydev register failure!");
   else
		printk("mydev register success!");
	return result;
}

 void dev_exit(void)
{
       	unregister_chrdev(CHAR_MAJOR_NUM, "zjdev");
}

/*static int dev_open(struct inode *inode, struct file *file)
{    
    // MOD_INC_USE_COUNT;
     printk("This module is in open!\n");
     return 0;
}

static int dev_release(struct inode *node, struct file *filp)
{      
    // MOD_DEC_USE_COUNT;
     printk("This module is in released!\n");
     return 0;
}*/
static int dev_open(struct inode *inode, struct file *file)
{    
     printk("\ndevice_open(%p,%p)\n",inode,file);
     if(device_open)
          return -EBUSY;      
     device_open++;
     try_module_get(THIS_MODULE);
     return 0;
}


static ssize_t dev_release(struct inode *node, struct file *filp)
{      
     printk("\ndevice_release(%p,%p)\n",node,filp);
     device_open--;
     module_put(THIS_MODULE);
     return 0;  
}

/*static ssize_t dev_read(struct file *f, char *buf, size_t len, loff_t *off)
{
	int i;      
	for(i=len;i>0;i--) {
		__put_user(5,buf);
		buf++;
	}
	return len;
}

static ssize_t dev_write(struct file *f, const char *buf,
		size_t len, loff_t *off)
{
       	if (copy_from_user(&test_major, buf, sizeof(int)))
		return 0;
  	return sizeof(int);
}*/

/*
static ssize_t dev_read(struct file *f, char *buf, size_t len, loff_t *off)
{
        int bytes_read=0;
        #ifdef DEBUG
           printk("\nmy_read is called.User buffer is %p,size is %d\n",buf,len);
        #endif
        if(verify_area(VERIFY_WRITE,buf,len)==-EFAULT)
           return -EFAULT;
        message_ptr=message;
        while(len&&*message_ptr)
                    {
            if(put_user(*(message_ptr++),buf++))
                return -EINVAL;
            len--;
            bytes_read++;
                   }
        return bytes_read;
}
*/
static static ssize_t dev_read(struct file *f, char *buf, size_t count, loff_t *off))
       {
       /* identify your data (device-specific code) */
         int i;
       for(i=count;i>0;i--)                 
         __put_user(5,buf++);              
         return count;
}


static ssize_t dev_write(struct file *f, const char *buf,size_t len, loff_t *off)
{
      int i;
      unsigned char uc;
      #ifdef DEBUG
        printk("\ndev_write is called.User buffer is %p,size is %d\n",buf,len);
      #endif
     // if(verify_area(VERIFY_WRITE,buf,len)==-EFAULT)
      //   return -EFAULT;
      printk("\nData below is from user programme:\n");
      for(i=0;i<len;i++)
         if(!get_user(uc,buf))
            printk("%02x",uc);
      return len;
}
/*static int dev_ioctl(struct inode *inode,struct file *f,unsigned int arg1,unsigned int arg2)
{
      #ifdef DEBUG
      printk("\nmy_ioctl is called.Paraeter is %p,size is %d\n",arg1);
      #endif
      switch(arg1)
           ｛
         case OPENSPK:
              printk("\nNow,open PC's speaker.\n"）；
              outb(inb(0x61)|3,0x61);
              break;
         case CLOSESPK:
              printk("\nNow ,close PC's speaker.");
              outb(inb(0x61)&0xfc,0x61);
              break;
             }
}*/
      


module_init(dev_init);
module_exit(dev_exit);