Linux驱动开发--自动创建设备文件节点

函数原型：

#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);}

实例：

在__init函数中，添加以下代码：

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=设备名;  

在__exit函数中，添加以下代码（在unregister_chrdev_region前）：

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