2 * This file is part of the libserialport project.
4 * Copyright (C) 2013 Martin Ling <martin-libserialport@earth.li>
6 * This program is free software: you can redistribute it and/or modify
7 * it under the terms of the GNU Lesser General Public License as
8 * published by the Free Software Foundation, either version 3 of the
9 * License, or (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
21 * @mainpage libserialport API
26 * libserialport is a minimal library written in C that is intended to take
27 * care of the OS-specific details when writing software that uses serial ports.
29 * By writing your serial code to use libserialport, you enable it to work
30 * transparently on any platform supported by the library.
32 * The operations that are supported are:
34 * - @ref Enumeration (obtaining a list of serial ports on the system)
36 * - @ref Configuration (baud rate, parity, etc.)
37 * - @ref Signals (modem control lines, breaks, etc.)
42 * libserialport is an open source project released under the LGPL3+ license.
47 * The API is simple, and designed to be a minimal wrapper around the serial
48 * port support in each OS.
50 * Most functions take a pointer to a struct sp_port, which represents a serial
51 * port. These structures are always allocated and freed by the library, using
52 * the functions in the @ref Enumeration "Enumeration" section.
54 * Most functions have return type @ref sp_return and can return only four
55 * possible error values:
57 * - @ref SP_ERR_ARG means that a function was called with invalid
58 * arguments. This implies a bug in the caller. The arguments passed would
59 * be invalid regardless of the underlying OS or serial device involved.
61 * - @ref SP_ERR_FAIL means that the OS reported a failure. The error code or
62 * message provided by the OS can be obtained by calling sp_last_error_code()
63 * or sp_last_error_message().
65 * - @ref SP_ERR_SUPP indicates that there is no support for the requested
66 * operation in the current OS, driver or device. No error message is
67 * available from the OS in this case. There is either no way to request
68 * the operation in the first place, or libserialport does not know how to
69 * do so in the current version.
71 * - @ref SP_ERR_MEM indicates that a memory allocation failed.
73 * All of these error values are negative.
75 * Calls that succeed return @ref SP_OK, which is equal to zero. Some functions
76 * declared @ref sp_return can also return a positive value for a successful
77 * numeric result, e.g. sp_blocking_read() or sp_blocking_write().
80 #ifndef LIBSERIALPORT_LIBSERIALPORT_H
81 #define LIBSERIALPORT_LIBSERIALPORT_H
91 /** Operation completed successfully. */
93 /** Invalid arguments were passed to the function. */
95 /** A system error occurred while executing the operation. */
97 /** A memory allocation failed while executing the operation. */
99 /** The requested operation is not supported by this system or device. */
103 /** Port access modes. */
105 /** Open port for read access. */
107 /** Open port for write access. */
109 /** Open port for read and write access. @since 0.1.1 */
110 SP_MODE_READ_WRITE = 3
115 /** Data received and ready to read. */
116 SP_EVENT_RX_READY = 1,
117 /** Ready to transmit new data. */
118 SP_EVENT_TX_READY = 2,
119 /** Error occurred. */
123 /** Buffer selection. */
127 /** Output buffer. */
133 /** Parity settings. */
135 /** Special value to indicate setting should be left alone. */
136 SP_PARITY_INVALID = -1,
149 /** RTS pin behaviour. */
151 /** Special value to indicate setting should be left alone. */
157 /** RTS used for flow control. */
158 SP_RTS_FLOW_CONTROL = 2
161 /** CTS pin behaviour. */
163 /** Special value to indicate setting should be left alone. */
167 /** CTS used for flow control. */
168 SP_CTS_FLOW_CONTROL = 1
171 /** DTR pin behaviour. */
173 /** Special value to indicate setting should be left alone. */
179 /** DTR used for flow control. */
180 SP_DTR_FLOW_CONTROL = 2
183 /** DSR pin behaviour. */
185 /** Special value to indicate setting should be left alone. */
189 /** DSR used for flow control. */
190 SP_DSR_FLOW_CONTROL = 1
193 /** XON/XOFF flow control behaviour. */
195 /** Special value to indicate setting should be left alone. */
196 SP_XONXOFF_INVALID = -1,
197 /** XON/XOFF disabled. */
198 SP_XONXOFF_DISABLED = 0,
199 /** XON/XOFF enabled for input only. */
201 /** XON/XOFF enabled for output only. */
203 /** XON/XOFF enabled for input and output. */
207 /** Standard flow control combinations. */
208 enum sp_flowcontrol {
209 /** No flow control. */
210 SP_FLOWCONTROL_NONE = 0,
211 /** Software flow control using XON/XOFF characters. */
212 SP_FLOWCONTROL_XONXOFF = 1,
213 /** Hardware flow control using RTS/CTS signals. */
214 SP_FLOWCONTROL_RTSCTS = 2,
215 /** Hardware flow control using DTR/DSR signals. */
216 SP_FLOWCONTROL_DTRDSR = 3
219 /** Input signals. */
221 /** Clear to send. */
223 /** Data set ready. */
225 /** Data carrier detect. */
227 /** Ring indicator. */
237 /** Native platform serial port. @since 0.1.1 */
239 /** USB serial port adapter. @since 0.1.1 */
241 /** Bluetooth serial port adapter. @since 0.1.1 */
242 SP_TRANSPORT_BLUETOOTH
247 * An opaque structure representing a serial port.
252 * @struct sp_port_config
253 * An opaque structure representing the configuration for a serial port.
255 struct sp_port_config;
258 * @struct sp_event_set
259 * A set of handles to wait on for events.
261 struct sp_event_set {
262 /** Array of OS-specific handles. */
264 /** Array of bitmasks indicating which events apply for each handle. */
265 enum sp_event *masks;
266 /** Number of handles. */
271 * @defgroup Enumeration Port enumeration
273 * Enumerating the serial ports of a system.
279 * Obtain a pointer to a new sp_port structure representing the named port.
281 * The user should allocate a variable of type "struct sp_port *" and pass a
282 * pointer to this to receive the result.
284 * The result should be freed after use by calling sp_free_port().
286 * If any error is returned, the variable pointed to by port_ptr will be set
287 * to NULL. Otherwise, it will be set to point to the newly allocated port.
289 * @return SP_OK upon success, a negative error code otherwise.
293 enum sp_return sp_get_port_by_name(const char *portname, struct sp_port **port_ptr);
296 * Free a port structure obtained from sp_get_port_by_name() or sp_copy_port().
300 void sp_free_port(struct sp_port *port);
303 * List the serial ports available on the system.
305 * The result obtained is an array of pointers to sp_port structures,
306 * terminated by a NULL. The user should allocate a variable of type
307 * "struct sp_port **" and pass a pointer to this to receive the result.
309 * The result should be freed after use by calling sp_free_port_list().
310 * If a port from the list is to be used after freeing the list, it must be
311 * copied first using sp_copy_port().
313 * If any error is returned, the variable pointed to by list_ptr will be set
314 * to NULL. Otherwise, it will be set to point to the newly allocated array.
316 * @return SP_OK upon success, a negative error code otherwise.
320 enum sp_return sp_list_ports(struct sp_port ***list_ptr);
323 * Make a new copy of a sp_port structure.
325 * The user should allocate a variable of type "struct sp_port *" and pass a
326 * pointer to this to receive the result.
328 * The copy should be freed after use by calling sp_free_port().
330 * If any error is returned, the variable pointed to by copy_ptr will be set
331 * to NULL. Otherwise, it will be set to point to the newly allocated copy.
333 * @return SP_OK upon success, a negative error code otherwise.
337 enum sp_return sp_copy_port(const struct sp_port *port, struct sp_port **copy_ptr);
340 * Free a port list obtained from sp_list_ports().
342 * This will also free all the sp_port structures referred to from the list;
343 * any that are to be retained must be copied first using sp_copy_port().
347 void sp_free_port_list(struct sp_port **ports);
351 * @defgroup Ports Port handling
353 * Opening, closing and querying ports.
359 * Open the specified serial port.
361 * @param port Pointer to port structure.
362 * @param flags Flags to use when opening the serial port.
364 * @return SP_OK upon success, a negative error code otherwise.
368 enum sp_return sp_open(struct sp_port *port, enum sp_mode flags);
371 * Close the specified serial port.
373 * @return SP_OK upon success, a negative error code otherwise.
377 enum sp_return sp_close(struct sp_port *port);
380 * Get the name of a port.
382 * The name returned is whatever is normally used to refer to a port on the
383 * current operating system; e.g. for Windows it will usually be a "COMn"
384 * device name, and for Unix it will be a device path beginning with "/dev/".
386 * @param port Pointer to port structure.
388 * @return The port name, or NULL if an invalid port is passed. The name
389 * string is part of the port structure and may not be used after the
390 * port structure has been freed.
394 char *sp_get_port_name(const struct sp_port *port);
397 * Get a description for a port, to present to end user.
399 * @param port Pointer to port structure.
401 * @return The port description, or NULL if an invalid port is passed.
402 * The description string is part of the port structure and may not be used
403 * after the port structure has been freed.
407 char *sp_get_port_description(struct sp_port *port);
410 * Get the transport type used by a port.
412 * @param port Pointer to port structure.
414 * @return The port transport type.
418 enum sp_transport sp_get_port_transport(struct sp_port *port);
421 * Get the USB bus number and address on bus of a USB serial adapter port.
423 * @param port Pointer to port structure.
424 * @param usb_bus Pointer to variable to store USB bus.
425 * @param usb_address Pointer to variable to store USB address
427 * @return SP_OK upon success, a negative error code otherwise.
431 enum sp_return sp_get_port_usb_bus_address(const struct sp_port *port,
432 int *usb_bus, int *usb_address);
435 * Get the USB Vendor ID and Product ID of a USB serial adapter port.
437 * @param port Pointer to port structure.
438 * @param usb_vid Pointer to variable to store USB VID.
439 * @param usb_pid Pointer to variable to store USB PID
441 * @return SP_OK upon success, a negative error code otherwise.
445 enum sp_return sp_get_port_usb_vid_pid(const struct sp_port *port, int *usb_vid, int *usb_pid);
448 * Get the USB manufacturer string of a USB serial adapter port.
450 * @param port Pointer to port structure.
452 * @return The port manufacturer string, or NULL if an invalid port is passed.
453 * The manufacturer string is part of the port structure and may not be used
454 * after the port structure has been freed.
458 char *sp_get_port_usb_manufacturer(const struct sp_port *port);
461 * Get the USB product string of a USB serial adapter port.
463 * @param port Pointer to port structure.
465 * @return The port product string, or NULL if an invalid port is passed.
466 * The product string is part of the port structure and may not be used
467 * after the port structure has been freed.
471 char *sp_get_port_usb_product(const struct sp_port *port);
474 * Get the USB serial number string of a USB serial adapter port.
476 * @param port Pointer to port structure.
478 * @return The port serial number, or NULL if an invalid port is passed.
479 * The serial number string is part of the port structure and may not be used
480 * after the port structure has been freed.
484 char *sp_get_port_usb_serial(const struct sp_port *port);
487 * Get the MAC address of a Bluetooth serial adapter port.
489 * @param port Pointer to port structure.
491 * @return The port MAC address, or NULL if an invalid port is passed.
492 * The MAC address string is part of the port structure and may not be used
493 * after the port structure has been freed.
497 char *sp_get_port_bluetooth_address(const struct sp_port *port);
500 * Get the operating system handle for a port.
502 * The type of the handle depends on the operating system. On Unix based
503 * systems, the handle is a file descriptor of type "int". On Windows, the
504 * handle is of type "HANDLE". The user should allocate a variable of the
505 * appropriate type and pass a pointer to this to receive the result.
507 * To obtain a valid handle, the port must first be opened by calling
508 * sp_open() using the same port structure.
510 * After the port is closed or the port structure freed, the handle may
511 * no longer be valid.
513 * @warning This feature is provided so that programs may make use of
514 * OS-specific functionality where desired. Doing so obviously
515 * comes at a cost in portability. It also cannot be guaranteed
516 * that direct usage of the OS handle will not conflict with the
517 * library's own usage of the port. Be careful.
519 * @return SP_OK upon success, a negative error code otherwise.
523 enum sp_return sp_get_port_handle(const struct sp_port *port, void *result_ptr);
528 * @defgroup Configuration Configuration
530 * Setting and querying serial port parameters.
535 * Allocate a port configuration structure.
537 * The user should allocate a variable of type "struct sp_config *" and pass a
538 * pointer to this to receive the result. The variable will be updated to
539 * point to the new configuration structure. The structure is opaque and must
540 * be accessed via the functions provided.
542 * All parameters in the structure will be initialised to special values which
543 * are ignored by sp_set_config().
545 * The structure should be freed after use by calling sp_free_config().
547 * @param config_ptr Pointer to variable to receive result.
549 * @return SP_OK upon success, a negative error code otherwise.
553 enum sp_return sp_new_config(struct sp_port_config **config_ptr);
556 * Free a port configuration structure.
558 * @param config Pointer to configuration structure.
562 void sp_free_config(struct sp_port_config *config);
565 * Get the current configuration of the specified serial port.
567 * The user should allocate a configuration structure using sp_new_config()
568 * and pass this as the config parameter. The configuration structure will
569 * be updated with the port configuration.
571 * Any parameters that are configured with settings not recognised or
572 * supported by libserialport, will be set to special values that are
573 * ignored by sp_set_config().
575 * @return SP_OK upon success, a negative error code otherwise.
579 enum sp_return sp_get_config(struct sp_port *port, struct sp_port_config *config);
582 * Set the configuration for the specified serial port.
584 * For each parameter in the configuration, there is a special value (usually
585 * -1, but see the documentation for each field). These values will be ignored
586 * and the corresponding setting left unchanged on the port.
588 * @return SP_OK upon success, a negative error code otherwise.
592 enum sp_return sp_set_config(struct sp_port *port, const struct sp_port_config *config);
595 * Set the baud rate for the specified serial port.
597 * @param port Pointer to port structure.
598 * @param baudrate Baud rate in bits per second.
600 * @return SP_OK upon success, a negative error code otherwise.
604 enum sp_return sp_set_baudrate(struct sp_port *port, int baudrate);
607 * Get the baud rate from a port configuration.
609 * The user should allocate a variable of type int and pass a pointer to this
610 * to receive the result.
612 * @param config Pointer to configuration structure.
613 * @param baudrate_ptr Pointer to variable to store result.
615 * @return SP_OK upon success, a negative error code otherwise.
619 enum sp_return sp_get_config_baudrate(const struct sp_port_config *config, int *baudrate_ptr);
622 * Set the baud rate in a port configuration.
624 * @param config Pointer to configuration structure.
625 * @param baudrate Baud rate in bits per second, or -1 to retain current setting.
627 * @return SP_OK upon success, a negative error code otherwise.
631 enum sp_return sp_set_config_baudrate(struct sp_port_config *config, int baudrate);
634 * Set the data bits for the specified serial port.
636 * @param port Pointer to port structure.
637 * @param bits Number of data bits.
639 * @return SP_OK upon success, a negative error code otherwise.
643 enum sp_return sp_set_bits(struct sp_port *port, int bits);
646 * Get the data bits from a port configuration.
648 * The user should allocate a variable of type int and pass a pointer to this
649 * to receive the result.
651 * @param config Pointer to configuration structure.
652 * @param bits_ptr Pointer to variable to store result.
654 * @return SP_OK upon success, a negative error code otherwise.
658 enum sp_return sp_get_config_bits(const struct sp_port_config *config, int *bits_ptr);
661 * Set the data bits in a port configuration.
663 * @param config Pointer to configuration structure.
664 * @param bits Number of data bits, or -1 to retain current setting.
666 * @return SP_OK upon success, a negative error code otherwise.
670 enum sp_return sp_set_config_bits(struct sp_port_config *config, int bits);
673 * Set the parity setting for the specified serial port.
675 * @param port Pointer to port structure.
676 * @param parity Parity setting.
678 * @return SP_OK upon success, a negative error code otherwise.
682 enum sp_return sp_set_parity(struct sp_port *port, enum sp_parity parity);
685 * Get the parity setting from a port configuration.
687 * The user should allocate a variable of type enum sp_parity and pass a pointer to this
688 * to receive the result.
690 * @param config Pointer to configuration structure.
691 * @param parity_ptr Pointer to variable to store result.
693 * @return SP_OK upon success, a negative error code otherwise.
697 enum sp_return sp_get_config_parity(const struct sp_port_config *config, enum sp_parity *parity_ptr);
700 * Set the parity setting in a port configuration.
702 * @param config Pointer to configuration structure.
703 * @param parity Parity setting, or -1 to retain current setting.
705 * @return SP_OK upon success, a negative error code otherwise.
709 enum sp_return sp_set_config_parity(struct sp_port_config *config, enum sp_parity parity);
712 * Set the stop bits for the specified serial port.
714 * @param port Pointer to port structure.
715 * @param stopbits Number of stop bits.
717 * @return SP_OK upon success, a negative error code otherwise.
721 enum sp_return sp_set_stopbits(struct sp_port *port, int stopbits);
724 * Get the stop bits from a port configuration.
726 * The user should allocate a variable of type int and pass a pointer to this
727 * to receive the result.
729 * @param config Pointer to configuration structure.
730 * @param stopbits_ptr Pointer to variable to store result.
732 * @return SP_OK upon success, a negative error code otherwise.
736 enum sp_return sp_get_config_stopbits(const struct sp_port_config *config, int *stopbits_ptr);
739 * Set the stop bits in a port configuration.
741 * @param config Pointer to configuration structure.
742 * @param stopbits Number of stop bits, or -1 to retain current setting.
744 * @return SP_OK upon success, a negative error code otherwise.
748 enum sp_return sp_set_config_stopbits(struct sp_port_config *config, int stopbits);
751 * Set the RTS pin behaviour for the specified serial port.
753 * @param port Pointer to port structure.
754 * @param rts RTS pin mode.
756 * @return SP_OK upon success, a negative error code otherwise.
760 enum sp_return sp_set_rts(struct sp_port *port, enum sp_rts rts);
763 * Get the RTS pin behaviour from a port configuration.
765 * The user should allocate a variable of type enum sp_rts and pass a pointer to this
766 * to receive the result.
768 * @param config Pointer to configuration structure.
769 * @param rts_ptr Pointer to variable to store result.
771 * @return SP_OK upon success, a negative error code otherwise.
775 enum sp_return sp_get_config_rts(const struct sp_port_config *config, enum sp_rts *rts_ptr);
778 * Set the RTS pin behaviour in a port configuration.
780 * @param config Pointer to configuration structure.
781 * @param rts RTS pin mode, or -1 to retain current setting.
783 * @return SP_OK upon success, a negative error code otherwise.
787 enum sp_return sp_set_config_rts(struct sp_port_config *config, enum sp_rts rts);
790 * Set the CTS pin behaviour for the specified serial port.
792 * @param port Pointer to port structure.
793 * @param cts CTS pin mode.
795 * @return SP_OK upon success, a negative error code otherwise.
799 enum sp_return sp_set_cts(struct sp_port *port, enum sp_cts cts);
802 * Get the CTS pin behaviour from a port configuration.
804 * The user should allocate a variable of type enum sp_cts and pass a pointer to this
805 * to receive the result.
807 * @param config Pointer to configuration structure.
808 * @param cts_ptr Pointer to variable to store result.
810 * @return SP_OK upon success, a negative error code otherwise.
814 enum sp_return sp_get_config_cts(const struct sp_port_config *config, enum sp_cts *cts_ptr);
817 * Set the CTS pin behaviour in a port configuration.
819 * @param config Pointer to configuration structure.
820 * @param cts CTS pin mode, or -1 to retain current setting.
822 * @return SP_OK upon success, a negative error code otherwise.
826 enum sp_return sp_set_config_cts(struct sp_port_config *config, enum sp_cts cts);
829 * Set the DTR pin behaviour for the specified serial port.
831 * @param port Pointer to port structure.
832 * @param dtr DTR pin mode.
834 * @return SP_OK upon success, a negative error code otherwise.
838 enum sp_return sp_set_dtr(struct sp_port *port, enum sp_dtr dtr);
841 * Get the DTR pin behaviour from a port configuration.
843 * The user should allocate a variable of type enum sp_dtr and pass a pointer to this
844 * to receive the result.
846 * @param config Pointer to configuration structure.
847 * @param dtr_ptr Pointer to variable to store result.
849 * @return SP_OK upon success, a negative error code otherwise.
853 enum sp_return sp_get_config_dtr(const struct sp_port_config *config, enum sp_dtr *dtr_ptr);
856 * Set the DTR pin behaviour in a port configuration.
858 * @param config Pointer to configuration structure.
859 * @param dtr DTR pin mode, or -1 to retain current setting.
861 * @return SP_OK upon success, a negative error code otherwise.
865 enum sp_return sp_set_config_dtr(struct sp_port_config *config, enum sp_dtr dtr);
868 * Set the DSR pin behaviour for the specified serial port.
870 * @param port Pointer to port structure.
871 * @param dsr DSR pin mode.
873 * @return SP_OK upon success, a negative error code otherwise.
877 enum sp_return sp_set_dsr(struct sp_port *port, enum sp_dsr dsr);
880 * Get the DSR pin behaviour from a port configuration.
882 * The user should allocate a variable of type enum sp_dsr and pass a pointer to this
883 * to receive the result.
885 * @param config Pointer to configuration structure.
886 * @param dsr_ptr Pointer to variable to store result.
888 * @return SP_OK upon success, a negative error code otherwise.
892 enum sp_return sp_get_config_dsr(const struct sp_port_config *config, enum sp_dsr *dsr_ptr);
895 * Set the DSR pin behaviour in a port configuration.
897 * @param config Pointer to configuration structure.
898 * @param dsr DSR pin mode, or -1 to retain current setting.
900 * @return SP_OK upon success, a negative error code otherwise.
904 enum sp_return sp_set_config_dsr(struct sp_port_config *config, enum sp_dsr dsr);
907 * Set the XON/XOFF configuration for the specified serial port.
909 * @param port Pointer to port structure.
910 * @param xon_xoff XON/XOFF mode.
912 * @return SP_OK upon success, a negative error code otherwise.
916 enum sp_return sp_set_xon_xoff(struct sp_port *port, enum sp_xonxoff xon_xoff);
919 * Get the XON/XOFF configuration from a port configuration.
921 * The user should allocate a variable of type enum sp_xonxoff and pass a pointer to this
922 * to receive the result.
924 * @param config Pointer to configuration structure.
925 * @param xon_xoff_ptr Pointer to variable to store result.
927 * @return SP_OK upon success, a negative error code otherwise.
931 enum sp_return sp_get_config_xon_xoff(const struct sp_port_config *config, enum sp_xonxoff *xon_xoff_ptr);
934 * Set the XON/XOFF configuration in a port configuration.
936 * @param config Pointer to configuration structure.
937 * @param xon_xoff XON/XOFF mode, or -1 to retain current setting.
939 * @return SP_OK upon success, a negative error code otherwise.
943 enum sp_return sp_set_config_xon_xoff(struct sp_port_config *config, enum sp_xonxoff xon_xoff);
946 * Set the flow control type in a port configuration.
948 * This function is a wrapper that sets the RTS, CTS, DTR, DSR and
949 * XON/XOFF settings as necessary for the specified flow control
950 * type. For more fine-grained control of these settings, use their
951 * individual configuration functions.
953 * @param config Pointer to configuration structure.
954 * @param flowcontrol Flow control setting to use.
956 * @return SP_OK upon success, a negative error code otherwise.
960 enum sp_return sp_set_config_flowcontrol(struct sp_port_config *config, enum sp_flowcontrol flowcontrol);
963 * Set the flow control type for the specified serial port.
965 * This function is a wrapper that sets the RTS, CTS, DTR, DSR and
966 * XON/XOFF settings as necessary for the specified flow control
967 * type. For more fine-grained control of these settings, use their
968 * individual configuration functions.
970 * @param port Pointer to port structure.
971 * @param flowcontrol Flow control setting to use.
973 * @return SP_OK upon success, a negative error code otherwise.
977 enum sp_return sp_set_flowcontrol(struct sp_port *port, enum sp_flowcontrol flowcontrol);
982 * @defgroup Data Data handling
984 * Reading, writing, and flushing data.
990 * Read bytes from the specified serial port, blocking until complete.
992 * @warning If your program runs on Unix, defines its own signal handlers, and
993 * needs to abort blocking reads when these are called, then you
994 * should not use this function. It repeats system calls that return
995 * with EINTR. To be able to abort a read from a signal handler, you
996 * should implement your own blocking read using sp_nonblocking_read()
997 * together with a blocking method that makes sense for your program.
998 * E.g. you can obtain the file descriptor for an open port using
999 * sp_get_port_handle() and use this to call select() or pselect(),
1000 * with appropriate arrangements to return if a signal is received.
1002 * @param port Pointer to port structure.
1003 * @param buf Buffer in which to store the bytes read.
1004 * @param count Requested number of bytes to read.
1005 * @param timeout Timeout in milliseconds, or zero to wait indefinitely.
1007 * @return The number of bytes read on success, or a negative error code. If
1008 * the number of bytes returned is less than that requested, the
1009 * timeout was reached before the requested number of bytes was
1010 * available. If timeout is zero, the function will always return
1011 * either the requested number of bytes or a negative error code.
1015 enum sp_return sp_blocking_read(struct sp_port *port, void *buf, size_t count, unsigned int timeout);
1018 * Read bytes from the specified serial port, without blocking.
1020 * @param port Pointer to port structure.
1021 * @param buf Buffer in which to store the bytes read.
1022 * @param count Maximum number of bytes to read.
1024 * @return The number of bytes read on success, or a negative error code. The
1025 * number of bytes returned may be any number from zero to the maximum
1026 * that was requested.
1030 enum sp_return sp_nonblocking_read(struct sp_port *port, void *buf, size_t count);
1033 * Write bytes to the specified serial port, blocking until complete.
1035 * Note that this function only ensures that the accepted bytes have been
1036 * written to the OS; they may be held in driver or hardware buffers and not
1037 * yet physically transmitted. To check whether all written bytes have actually
1038 * been transmitted, use the sp_output_waiting() function. To wait until all
1039 * written bytes have actually been transmitted, use the sp_drain() function.
1041 * @warning If your program runs on Unix, defines its own signal handlers, and
1042 * needs to abort blocking writes when these are called, then you
1043 * should not use this function. It repeats system calls that return
1044 * with EINTR. To be able to abort a write from a signal handler, you
1045 * should implement your own blocking write using sp_nonblocking_write()
1046 * together with a blocking method that makes sense for your program.
1047 * E.g. you can obtain the file descriptor for an open port using
1048 * sp_get_port_handle() and use this to call select() or pselect(),
1049 * with appropriate arrangements to return if a signal is received.
1051 * @param port Pointer to port structure.
1052 * @param buf Buffer containing the bytes to write.
1053 * @param count Requested number of bytes to write.
1054 * @param timeout Timeout in milliseconds, or zero to wait indefinitely.
1056 * @return The number of bytes written on success, or a negative error code.
1057 * If the number of bytes returned is less than that requested, the
1058 * timeout was reached before the requested number of bytes was
1059 * written. If timeout is zero, the function will always return
1060 * either the requested number of bytes or a negative error code. In
1061 * the event of an error there is no way to determine how many bytes
1062 * were sent before the error occurred.
1066 enum sp_return sp_blocking_write(struct sp_port *port, const void *buf, size_t count, unsigned int timeout);
1069 * Write bytes to the specified serial port, without blocking.
1071 * Note that this function only ensures that the accepted bytes have been
1072 * written to the OS; they may be held in driver or hardware buffers and not
1073 * yet physically transmitted. To check whether all written bytes have actually
1074 * been transmitted, use the sp_output_waiting() function. To wait until all
1075 * written bytes have actually been transmitted, use the sp_drain() function.
1077 * @param port Pointer to port structure.
1078 * @param buf Buffer containing the bytes to write.
1079 * @param count Maximum number of bytes to write.
1081 * @return The number of bytes written on success, or a negative error code.
1082 * The number of bytes returned may be any number from zero to the
1083 * maximum that was requested.
1087 enum sp_return sp_nonblocking_write(struct sp_port *port, const void *buf, size_t count);
1090 * Gets the number of bytes waiting in the input buffer.
1092 * @param port Pointer to port structure.
1094 * @return Number of bytes waiting on success, a negative error code otherwise.
1098 enum sp_return sp_input_waiting(struct sp_port *port);
1101 * Gets the number of bytes waiting in the output buffer.
1103 * @param port Pointer to port structure.
1105 * @return Number of bytes waiting on success, a negative error code otherwise.
1109 enum sp_return sp_output_waiting(struct sp_port *port);
1112 * Flush serial port buffers. Data in the selected buffer(s) is discarded.
1114 * @param port Pointer to port structure.
1115 * @param buffers Which buffer(s) to flush.
1117 * @return SP_OK upon success, a negative error code otherwise.
1121 enum sp_return sp_flush(struct sp_port *port, enum sp_buffer buffers);
1124 * Wait for buffered data to be transmitted.
1126 * @warning If your program runs on Unix, defines its own signal handlers, and
1127 * needs to abort draining the output buffer when when these are
1128 * called, then you should not use this function. It repeats system
1129 * calls that return with EINTR. To be able to abort a drain from a
1130 * signal handler, you would need to implement your own blocking
1131 * drain by polling the result of sp_output_waiting().
1133 * @param port Pointer to port structure.
1135 * @return SP_OK upon success, a negative error code otherwise.
1139 enum sp_return sp_drain(struct sp_port *port);
1144 * @defgroup Waiting Waiting
1146 * Waiting for events and timeout handling.
1152 * Allocate storage for a set of events.
1154 * The user should allocate a variable of type struct sp_event_set *,
1155 * then pass a pointer to this variable to receive the result.
1157 * The result should be freed after use by calling sp_free_event_set().
1159 * @return SP_OK upon success, a negative error code otherwise.
1163 enum sp_return sp_new_event_set(struct sp_event_set **result_ptr);
1166 * Add events to a struct sp_event_set for a given port.
1168 * The port must first be opened by calling sp_open() using the same port
1171 * After the port is closed or the port structure freed, the results may
1172 * no longer be valid.
1174 * @param event_set Event set to update.
1175 * @param port Pointer to port structure.
1176 * @param mask Bitmask of events to be waited for.
1178 * @return SP_OK upon success, a negative error code otherwise.
1182 enum sp_return sp_add_port_events(struct sp_event_set *event_set,
1183 const struct sp_port *port, enum sp_event mask);
1186 * Wait for any of a set of events to occur.
1188 * @param event_set Event set to wait on.
1189 * @param timeout Timeout in milliseconds, or zero to wait indefinitely.
1191 * @return SP_OK upon success, a negative error code otherwise.
1195 enum sp_return sp_wait(struct sp_event_set *event_set, unsigned int timeout);
1198 * Free a structure allocated by sp_new_event_set().
1202 void sp_free_event_set(struct sp_event_set *event_set);
1207 * @defgroup Signals Signals
1209 * Port signalling operations.
1215 * Gets the status of the control signals for the specified port.
1217 * The user should allocate a variable of type "enum sp_signal" and pass a
1218 * pointer to this variable to receive the result. The result is a bitmask
1219 * in which individual signals can be checked by bitwise OR with values of
1220 * the sp_signal enum.
1222 * @param port Pointer to port structure.
1223 * @param signal_mask Pointer to variable to receive result.
1225 * @return SP_OK upon success, a negative error code otherwise.
1229 enum sp_return sp_get_signals(struct sp_port *port, enum sp_signal *signal_mask);
1232 * Put the port transmit line into the break state.
1234 * @param port Pointer to port structure.
1236 * @return SP_OK upon success, a negative error code otherwise.
1240 enum sp_return sp_start_break(struct sp_port *port);
1243 * Take the port transmit line out of the break state.
1245 * @param port Pointer to port structure.
1247 * @return SP_OK upon success, a negative error code otherwise.
1251 enum sp_return sp_end_break(struct sp_port *port);
1256 * @defgroup Errors Errors
1258 * Obtaining error information.
1264 * Get the error code for a failed operation.
1266 * In order to obtain the correct result, this function should be called
1267 * straight after the failure, before executing any other system operations.
1269 * @return The system's numeric code for the error that caused the last
1270 * operation to fail.
1274 int sp_last_error_code(void);
1277 * Get the error message for a failed operation.
1279 * In order to obtain the correct result, this function should be called
1280 * straight after the failure, before executing other system operations.
1282 * @return The system's message for the error that caused the last
1283 * operation to fail. This string may be allocated by the function,
1284 * and should be freed after use by calling sp_free_error_message().
1288 char *sp_last_error_message(void);
1291 * Free an error message returned by sp_last_error_message().
1295 void sp_free_error_message(char *message);
1298 * Set the handler function for library debugging messages.
1300 * Debugging messages are generated by the library during each operation,
1301 * to help in diagnosing problems. The handler will be called for each
1302 * message. The handler can be set to NULL to ignore all debug messages.
1304 * The handler function should accept a format string and variable length
1305 * argument list, in the same manner as e.g. printf().
1307 * The default handler is sp_default_debug_handler().
1311 void sp_set_debug_handler(void (*handler)(const char *format, ...));
1314 * Default handler function for library debugging messages.
1316 * This function prints debug messages to the standard error stream if the
1317 * environment variable LIBSERIALPORT_DEBUG is set. Otherwise, they are
1322 void sp_default_debug_handler(const char *format, ...);
1327 * @defgroup Versions Versions
1329 * Version number querying functions, definitions, and macros.
1331 * This set of API calls returns two different version numbers related
1332 * to libserialport. The "package version" is the release version number of the
1333 * libserialport tarball in the usual "major.minor.micro" format, e.g. "0.1.0".
1335 * The "library version" is independent of that; it is the libtool version
1336 * number in the "current:revision:age" format, e.g. "2:0:0".
1337 * See http://www.gnu.org/software/libtool/manual/libtool.html#Libtool-versioning for details.
1339 * Both version numbers (and/or individual components of them) can be
1340 * retrieved via the API calls at runtime, and/or they can be checked at
1341 * compile/preprocessor time using the respective macros.
1347 * Package version macros (can be used for conditional compilation).
1350 /** The libserialport package 'major' version number. */
1351 #define SP_PACKAGE_VERSION_MAJOR @SP_PACKAGE_VERSION_MAJOR@
1353 /** The libserialport package 'minor' version number. */
1354 #define SP_PACKAGE_VERSION_MINOR @SP_PACKAGE_VERSION_MINOR@
1356 /** The libserialport package 'micro' version number. */
1357 #define SP_PACKAGE_VERSION_MICRO @SP_PACKAGE_VERSION_MICRO@
1359 /** The libserialport package version ("major.minor.micro") as string. */
1360 #define SP_PACKAGE_VERSION_STRING "@SP_PACKAGE_VERSION@"
1363 * Library/libtool version macros (can be used for conditional compilation).
1366 /** The libserialport libtool 'current' version number. */
1367 #define SP_LIB_VERSION_CURRENT @SP_LIB_VERSION_CURRENT@
1369 /** The libserialport libtool 'revision' version number. */
1370 #define SP_LIB_VERSION_REVISION @SP_LIB_VERSION_REVISION@
1372 /** The libserialport libtool 'age' version number. */
1373 #define SP_LIB_VERSION_AGE @SP_LIB_VERSION_AGE@
1375 /** The libserialport libtool version ("current:revision:age") as string. */
1376 #define SP_LIB_VERSION_STRING "@SP_LIB_VERSION@"
1379 * Get the major libserialport package version number.
1381 * @return The major package version number.
1385 int sp_get_major_package_version(void);
1388 * Get the minor libserialport package version number.
1390 * @return The minor package version number.
1394 int sp_get_minor_package_version(void);
1397 * Get the micro libserialport package version number.
1399 * @return The micro package version number.
1403 int sp_get_micro_package_version(void);
1406 * Get the libserialport package version number as a string.
1408 * @return The package version number string. The returned string is
1409 * static and thus should NOT be free'd by the caller.
1413 const char *sp_get_package_version_string(void);
1416 * Get the "current" part of the libserialport library version number.
1418 * @return The "current" library version number.
1422 int sp_get_current_lib_version(void);
1425 * Get the "revision" part of the libserialport library version number.
1427 * @return The "revision" library version number.
1431 int sp_get_revision_lib_version(void);
1434 * Get the "age" part of the libserialport library version number.
1436 * @return The "age" library version number.
1440 int sp_get_age_lib_version(void);
1443 * Get the libserialport library version number as a string.
1445 * @return The library version number string. The returned string is
1446 * static and thus should NOT be free'd by the caller.
1450 const char *sp_get_lib_version_string(void);