+/**
+ * @}
+ * @defgroup Ports Opening and closing ports
+ * @{
+ */
+
+/**
+ * Open the specified serial port.
+ *
+ * @param port Pointer to port structure.
+ * @param flags Flags to use when opening the serial port.
+ *
+ * @return SP_OK on success, SP_ERR_FAIL on failure, SP_ERR_MEM on allocation
+ * failure, or SP_ERR_ARG if an invalid port is passed.
+ */
+enum sp_return sp_open(struct sp_port *port, enum sp_mode flags);
+
+/**
+ * Close the specified serial port.
+ *
+ * @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG
+ * if an invalid port is passed.
+ */
+enum sp_return sp_close(struct sp_port *port);
+
+/**
+ * @}
+ * @defgroup Configuration Setting port parameters
+ * @{
+ */
+
+/**
+ * Get the current configuration of the specified serial port.
+ *
+ * The user should allocate a struct sp_port_config, then pass a pointer to it
+ * as the config parameter. The struct will be populated with the port
+ * configuration.
+ *
+ * Any setting that is in a state not recognised or supported by
+ * libserialport will have its value set to -1 in the struct.
+ *
+ * @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG
+ * for invalid arguments.
+ */
+enum sp_return sp_get_config(struct sp_port *port, struct sp_port_config *config);
+
+/**
+ * Set the configuration for the specified serial port.
+ *
+ * The user should populate a struct sp_port_config, then pass a pointer to it
+ * as the config parameter.
+ *
+ * To retain the current value of any setting, set that field to -1.
+ *
+ * @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG
+ * for invalid arguments.
+ */
+enum sp_return sp_set_config(struct sp_port *port, const struct sp_port_config *config);
+
+/**
+ * Set the baud rate for the specified serial port.
+ *
+ * @param port Pointer to port structure.
+ * @param baudrate Baud rate in bits per second.
+ *
+ * @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG
+ * for invalid arguments.
+ */
+enum sp_return sp_set_baudrate(struct sp_port *port, int baudrate);
+
+/**
+ * Set the number of data bits for the specified serial port.
+ *
+ * @param port Pointer to port structure.
+ * @param bits Number of data bits to use. Valid values are 5 to 8.
+ *
+ * @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG
+ * for invalid arguments.
+ */
+enum sp_return sp_set_bits(struct sp_port *port, int bits);
+
+/**
+ * Set the parity for the specified serial port.
+ *
+ * @param port Pointer to port structure.
+ * @param parity Parity setting to use.
+ *
+ * @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG
+ * for invalid arguments.
+ */
+enum sp_return sp_set_parity(struct sp_port *port, enum sp_parity parity);
+
+/**
+ * Set the number of stop bits for the specified port.
+ *
+ * @param port Pointer to port structure.
+ * @param stopbits Number of stop bits to use (1 or 2).
+ *
+ * @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG
+ * for invalid arguments.
+ */
+enum sp_return sp_set_stopbits(struct sp_port *port, int stopbits);
+
+/**
+ * Set the flow control type for the specified serial port.
+ *
+ * This function is a wrapper that sets the RTS, CTS, DTR, DSR and
+ * XON/XOFF settings as necessary for the specified flow control
+ * type. For more fine-grained control of these settings, use their
+ * individual configuration functions or the sp_set_config() function.
+ *
+ * @param port Pointer to port structure.
+ * @param flowcontrol Flow control setting to use.
+ *
+ * @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG
+ * for invalid arguments.
+ */
+enum sp_return sp_set_flowcontrol(struct sp_port *port, enum sp_flowcontrol flowcontrol);
+
+/**
+ * Set the RTS pin behaviour for the specified port.
+ *
+ * @param port Pointer to port structure.
+ * @param rts RTS pin mode.
+ *
+ * @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG
+ * for invalid arguments.
+ */
+enum sp_return sp_set_rts(struct sp_port *port, enum sp_rts rts);
+
+/**
+ * Set the CTS pin behaviour for the specified port.
+ *
+ * @param port Pointer to port structure.
+ * @param cts CTS pin mode.
+ *
+ * @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG
+ * for invalid arguments.
+ */
+enum sp_return sp_set_cts(struct sp_port *port, enum sp_cts cts);
+
+/**
+ * Set the DTR pin behaviour for the specified port.
+ *
+ * @param port Pointer to port structure.
+ * @param dtr DTR pin mode.
+ *
+ * @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG
+ * for invalid arguments.
+ */
+enum sp_return sp_set_dtr(struct sp_port *port, enum sp_dtr dtr);
+
+/**
+ * Set the RTS pin behaviour for the specified port.
+ *
+ * @param port Pointer to port structure.
+ * @param dsr DSR pin mode.
+ *
+ * @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG
+ * for invalid arguments.
+ */
+enum sp_return sp_set_dsr(struct sp_port *port, enum sp_dsr dsr);
+
+/**
+ * Configure XON/XOFF flow control for the specified port.
+ *
+ * @param port Pointer to port structure.
+ * @param xon_xoff XON/XOFF flow control mode.
+ *
+ * @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG
+ * for invalid arguments.
+ */
+enum sp_return sp_set_xon_xoff(struct sp_port *port, enum sp_xonxoff xon_xoff);
+
+/**
+ * @}
+ * @defgroup Data Reading, writing, and flushing data
+ * @{
+*/
+
+/**
+ * Read bytes from the specified serial port.
+ *
+ * Note that this function may return after reading less than the specified
+ * number of bytes; it is the user's responsibility to iterate as necessary
+ * in this case.
+ *
+ * @param port Pointer to port structure.
+ * @param buf Buffer in which to store the bytes read.
+ * @param count Maximum number of bytes to read.
+ *
+ * @return The number of bytes read, SP_ERR_FAIL on failure,
+ * or SP_ERR_ARG for invalid arguments.
+ */
+enum sp_return sp_read(struct sp_port *port, void *buf, size_t count);
+
+/**
+ * Write bytes to the specified serial port.
+ *
+ * Note that this function may return after writing less than the specified
+ * number of bytes; it is the user's responsibility to iterate as necessary
+ * in this case.
+ *
+ * @param port Pointer to port structure.
+ * @param buf Buffer containing the bytes to write.
+ * @param count Maximum number of bytes to write.
+ *
+ * @return The number of bytes written, SP_ERR_FAIL on failure,
+ * or SP_ERR_ARG for invalid arguments.
+ */
+enum sp_return sp_write(struct sp_port *port, const void *buf, size_t count);
+
+/**
+ * Flush serial port buffers. Data in the selected buffer(s) is discarded.
+ *
+ * @param port Pointer to port structure.
+ * @param buffers Which buffer(s) to flush.
+ *
+ * @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG
+ * if an invalid port is passed.
+ */
+enum sp_return sp_flush(struct sp_port *port, enum sp_buffer buffers);
+
+/**
+ * Wait for buffered data to be transmitted.
+ *
+ * @param port Pointer to port structure.
+ *
+ * @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG
+ * if an invalid port is passed.
+ */
+enum sp_return sp_drain(struct sp_port *port);
+
+/**
+ * @}
+ * @defgroup Signal Port signalling operations
+ * @{
+ */
+
+/**
+ * Gets the status of the control signals for the specified port.
+ *
+ * The user should allocate a variable of type "enum sp_signal" and pass a
+ * pointer to this variable to receive the result. The result is a bitmask
+ * in which individual signals can be checked by bitwise OR with values of
+ * the sp_signal enum.
+ *
+ * @param port Pointer to port structure.
+ * @param signals Pointer to variable to receive result.
+ *
+ * @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG
+ * if an an invalid port or pointer is passed.
+ */
+enum sp_return sp_get_signals(struct sp_port *port, enum sp_signal *signals);
+
+/**
+ * Put the port transmit line into the break state.
+ *
+ * @param port Pointer to port structure.
+ *
+ * @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG
+ * if an invalid port is passed.
+ */
+enum sp_return sp_start_break(struct sp_port *port);
+
+/**
+ * Take the port transmit line out of the break state.
+ *
+ * @param port Pointer to port structure.
+ *
+ * @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG
+ * if an invalid port is passed.
+ */
+enum sp_return sp_end_break(struct sp_port *port);
+
+/**
+ * @}
+ * @defgroup Errors Obtaining error information
+ * @{
+*/
+
+/**
+ * Get the error code for a failed operation.
+ *
+ * In order to obtain the correct result, this function should be called
+ * straight after the failure, before executing any other system operations.
+ *
+ * @return The system's numeric code for the error that caused the last
+ * operation to fail.
+ */