-int demo_hello(struct device *dev, int ch);
-int demo_status(struct device *dev, int *status);
+int demo_hello(struct udevice *dev, int ch);
+int demo_status(struct udevice *dev, int *status);
+int demo_set_light(struct udevice *dev, int light);
+int demo_get_light(struct udevice *dev);