+/**
+ * Request ownership of a GPIO.
+ *
+ * @param gpio GPIO number
+ * @param label Name given to the GPIO
+ * @return 0 if ok, -1 on error
+ */
+int gpio_request(unsigned gpio, const char *label);
+
+/**
+ * Stop using the GPIO. This function should not alter pin configuration.
+ *
+ * @param gpio GPIO number
+ * @return 0 if ok, -1 on error
+ */
+int gpio_free(unsigned gpio);
+