- * If any error is returned, the variable pointed to by port_ptr will be set
- * to NULL. Otherwise, it will be set to point to the newly allocated port.
+ * @param[in] portname The OS-specific name of a serial port. Must not be NULL.
+ * @param[out] port_ptr If any error is returned, the variable pointed to by
+ * port_ptr will be set to NULL. Otherwise, it will be set
+ * to point to the newly allocated port. Must not be NULL.