struct class_device {
  struct list_head node;

  struct kobject   kobj;
  struct class    *class;
  dev_t            devt;
  struct class_device_attribute *devt_attr;
  struct device   *dev;
  void            *class_data;
  struct class_device *parent;

  void (*release)(struct class_device *dev);
  int  (*hotplug)(struct class_device *dev, char **envp,
                  int num_envp, char *buffer, int buffer_size);
  char class_id[BUS_ID_SIZE];
};