extern struct sysfs_device *sysfs_device_get(const char *devpath);
extern struct sysfs_device *sysfs_device_get_parent(struct sysfs_device *dev);
extern struct sysfs_device *sysfs_device_get_parent_with_subsystem(struct sysfs_device *dev, const char *subsystem);
extern char *sysfs_attr_get_value(const char *devpath, const char *attr_name);
extern struct sysfs_device *sysfs_device_get(const char *devpath);
extern struct sysfs_device *sysfs_device_get_parent(struct sysfs_device *dev);
extern struct sysfs_device *sysfs_device_get_parent_with_subsystem(struct sysfs_device *dev, const char *subsystem);
extern char *sysfs_attr_get_value(const char *devpath, const char *attr_name);