#define to_class_dev(obj) container_of(obj,struct class_device,kobj)
#define to_net_dev(class) container_of(class, struct net_device, class_dev)
#define to_class_dev(obj) container_of(obj,struct class_device,kobj)
#define to_net_dev(class) container_of(class, struct net_device, class_dev)