请大家帮慢看一个驱动程序的问题，读没问题，写不行，

  驱动编译没有错误，初始化和read（）都没有问题。
但是当我在应用程序中调用write（）函数的时候，老是返回-1。应该是static int s3c2410_write(struct file * file,const char * buffer, size_t count, loff_t *ppos)根本就没有执行，狂不解！！
请教大牛们！！急死我了！
#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>

#include <asm/io.h>
#include <linux/miscdevice.h>
#include <linux/sched.h>
#include <linux/delay.h>
#include <linux/poll.h>
#include <linux/spinlock.h>
#include <linux/irq.h>
#include <asm/arch/irqs.h>
#include <asm/delay.h>
#include <asm/arch/S3C2410.h>
#include <asm/hardware.h>

#define DEVICE_NAME       "IIC"
#define IIC_MAJOR 233
#define IICBUFSIZE 20

static DECLARE_WAIT_QUEUE_HEAD(s3c2410_wait);

static char iic_Data[IICBUFSIZE];
static volatile int iic_DataCount;


static int s3c2410_write(struct file * file,const char * buffer, size_t count, loff_t *ppos)
{
                iic_DataCount=count;
           printk("WRITE\n");
           copy_from_user(iic_Data,buffer,count);
       return 0;
}

static int s3c2410_read(struct file * file, char * buffer, size_t count, loff_t *ppos)
{
       int i;
       iic_DataCount=count;
       printk("READ\n");
       for(i=0;i<count;i++)   iic_Data=i*2;
       copy_to_user(buffer,iic_Data,iic_DataCount);
                return count;
}


static struct file_operations s3c2410_fops =
{
       owner:       THIS_MODULE,
       read: s3c2410_read,
       write: s3c2410_write,
};

static devfs_handle_t devfs_handle;
static int __init s3c2410_init(void)
{
       int ret;
      
       ret = register_chrdev(IIC_MAJOR, DEVICE_NAME, &s3c2410_fops);
       if (ret < 0) {
         printk(DEVICE_NAME " can't register major number\n");
         return ret;
       }
       devfs_handle = devfs_register(NULL, DEVICE_NAME, DEVFS_FL_DEFAULT,IIC_MAJOR, 0, S_IFCHR | S_IRUSR | S_IWUSR,&s3c2410_fops, NULL);

       return 0;
}

static void __exit s3c2410_exit(void)
{

       devfs_unregister(devfs_handle);
       unregister_chrdev(IIC_MAJOR, DEVICE_NAME);
}
module_init(s3c2410_init);
module_exit(s3c2410_exit);