extern struct sysfs_class_device *wait_class_device_open(const char *path);
extern int wait_for_class_device(struct sysfs_class_device *class_dev, const char **error);
extern struct sysfs_class_device *wait_class_device_open(const char *path);
extern int wait_for_class_device(struct sysfs_class_device *class_dev, const char **error);