Linux驅動開發--自動創建設備文件節點

函數原型：

#define class_create(owner, name)		\
({						\
	static struct lock_class_key __key;	\
	__class_create(owner, name, &__key);	\
})

struct device *device_create(struct class *class, struct device *parent,
			     dev_t devt, void *drvdata, const char *fmt, ...)
{
	va_list vargs;
	struct device *dev;

	va_start(vargs, fmt);
	dev = device_create_vargs(class, parent, devt, drvdata, fmt, vargs);
	va_end(vargs);
	return dev;
}

void device_destroy(struct class *class, dev_t devt) {  struct device *dev;

 dev = class_find_device(class, NULL, &devt, __match_devt);  if (dev) {   put_device(dev);   device_unregister(dev);  } }

void class_destroy(struct class *cls)
{
	if ((cls == NULL) || (IS_ERR(cls)))
		return;

	class_unregister(cls);
}

實例：

在__init函數中，添加以下代碼：

my_class= class_create(THIS_MODULE, "my_class");

if(IS_ERR(my_class)) 
{
       printk("Err: failed increating class.\n");

       return -1; 

 }
 device_create( my_class, NULL, devno,NULL, DEV_NAME);//DEV_NAME=設備名;  

在__exit函數中，添加以下代碼（在unregister_chrdev_region前）：

device_destroy(virtual_disk_class, MKDEV(VirtualDisk_major, 0));
class_destroy(virtual_disk_class);