Linux驱动——如何创建一个字符设备

#include 
#include 
#include 
#include 

#define DEV_NUM 110
#define DEV_CNT 1

dev_t dev;
int dev_init(void)
{
	int ret;
	dev = MKDEV(DEV_NUM, DEV_CNT);
	ret = alloc_chrdev_region(&dev,DEV_NUM, DEV_CNT, "alloc_test");
	if(ret < 0) {
		printk("alloc_register failed!n");
		return -ENODEV;
	}
	printk("alloc_register successed!n");
	return 0;
}

void dev_exit(void)
{
	unregister_chrdev_region(dev, DEV_CNT);
	printk("alloc_register completed!n");
}
module_init(dev_init);
module_exit(dev_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("David-Woo");
MODULE_DEscriptION("alloc register example");