+ Obtains a pointer to a new sp_port structure representing the named port. The
+ user should allocate a variable of type "struct sp_port *" and pass a pointer
+ to this to receive the result.
+
+ The result should be freed after use by calling sp_free_port().
+
+ Returns: SP_OK on success, SP_ERR_FAIL on failure, SP_ERR_MEM on allocation
+ failure, or SP_ERR_ARG if an invalid pointer is passed. 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.
+
+void sp_free_port(struct sp_port *port);
+
+ Frees a port structure obtained from sp_get_port_by_name().
+
+int sp_list_ports(struct sp_port ***list_ptr);
+
+ Lists the serial ports available on the system. The result obtained is an
+ array of pointers to sp_port structures, terminated by a NULL. The user should
+ allocate a variable of type "struct sp_port **" and pass a pointer to this to
+ receive the result.
+
+ The result should be freed after use by calling sp_free_port_list(). If a port
+ from the list is to be used after freeing the list, it must be copied first
+ using sp_copy_port().
+
+ Returns: SP_OK on success, SP_ERR_FAIL on failure, SP_ERR_MEM on allocation
+ failure, or SP_ERR_ARG if an invalid pointer is passed. If any error
+ is returned, the variable pointed to by list_ptr will be set to NULL.
+ Otherwise, it will be set to point to the newly allocated array.
+
+int sp_copy_port(const struct sp_port *port, struct sp_port **copy_ptr);
+
+ Makes a new copy of a sp_port structure. The user should allocate a variable
+ of type "struct sp_port *" and pass a pointer to this to receive the result.
+
+ The copy should be freed after use by calling sp_free_port().
+
+ Returns: SP_OK on success, SP_ERR_MEM on allocation failure, or SP_ERR_ARG
+ if an invalid port or pointer is passed. If any error is returned,
+ the variable pointed to by copy_ptr will be set to NULL. Otherwise,
+ it will be set to point to the newly allocated copy.