linux添加驱动到内核

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/fs.h>

#define DEVICE_NAME "mydevice"
#define MAJOR_NUM 240

static int device_open(struct inode *, struct file *);
static int device_release(struct inode *, struct file *);
static ssize_t device_read(struct file *, char *, size_t, loff_t *);
static ssize_t device_write(struct file *, const char *, size_t, loff_t *);

static struct file_operations fops = {
   .open = device_open,
   .release = device_release,
   .read = device_read,
   .write = device_write,
};

static int __init mydriver_init(void) {
   int ret_val;
   ret_val = register_chrdev(MAJOR_NUM, DEVICE_NAME, &fops);
   if (ret_val < 0) {
      printk(KERN_ALERT "Failed to register device\n");
      return ret_val;
   }
   printk(KERN_INFO "Device registered successfully\n");
   return 0;
}

static void __exit mydriver_exit(void) {
   unregister_chrdev(MAJOR_NUM, DEVICE_NAME);
   printk(KERN_INFO "Device unregistered successfully\n");
}

module_init(mydriver_init);
module_exit(mydriver_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Your Name");
MODULE_DESCRIPTION("A simple character device driver");