#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <asm/uaccess.h>    
#include <asm/io.h>        

#define DEVICE_NAME "seeprom"
#define RANDOM_READ_BYTE 1000
#define RANDOM_WRITE_BYTE 2000
struct address_data {
    int address, data;
};
int write_data(int addr, unsigned char data);
int read_data(int addr);
static int Major;    
static int i2c_ioctl (struct inode *inode, struct file *file,
        unsigned int ioctl_num, unsigned long ioctl_param)
{
    struct address_data ad;
    int addr, r;
    
    switch(ioctl_num) {
    case RANDOM_READ_BYTE:
        get_user(addr, (int*)ioctl_param);
         r = read_data(addr);
        if (r == -1) return -EIO;
        put_user(r, (int*)ioctl_param);
        break;
    case RANDOM_WRITE_BYTE:
        copy_from_user(&ad, (struct address_data*)ioctl_param, 
            sizeof(struct address_data));
        r = write_data(ad.address, ad.data);
        if (r == -1) return -EIO;
        break;
    default: return -EIO;
    }
    return 0;
}
static struct file_operations fops = {
    .ioctl = i2c_ioctl,
};
int init_module (void)
{
    Major = register_chrdev (0, DEVICE_NAME, &fops);
    if (Major < 0) {
        printk("Registering the character device ");
        printk("failed with %d\n", Major);
        return Major;
    }
     return 0;
}
void
cleanup_module (void)
{
    int ret = unregister_chrdev (Major, DEVICE_NAME);
    if (ret < 0)
        printk ("Error in unregistering: %d\n", ret);
}