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
94 /** Operation completed successfully. */
96 /** Invalid arguments were passed to the function. */
98 /** A system error occurred while executing the operation. */
100 /** A memory allocation failed while executing the operation. */
102 /** The requested operation is not supported by this system or device. */
106 /** Port access modes. */
108 /** Open port for read access. */
110 /** Open port for write access. */
112 /** Open port for read and write access. @since 0.1.1 */
113 SP_MODE_READ_WRITE = 3
118 /** Data received and ready to read. */
119 SP_EVENT_RX_READY = 1,
120 /** Ready to transmit new data. */
121 SP_EVENT_TX_READY = 2,
122 /** Error occurred. */
126 /** Buffer selection. */
130 /** Output buffer. */
136 /** Parity settings. */
138 /** Special value to indicate setting should be left alone. */
139 SP_PARITY_INVALID = -1,
152 /** RTS pin behaviour. */
154 /** Special value to indicate setting should be left alone. */
160 /** RTS used for flow control. */
161 SP_RTS_FLOW_CONTROL = 2
164 /** CTS pin behaviour. */
166 /** Special value to indicate setting should be left alone. */
170 /** CTS used for flow control. */
171 SP_CTS_FLOW_CONTROL = 1
174 /** DTR pin behaviour. */
176 /** Special value to indicate setting should be left alone. */
182 /** DTR used for flow control. */
183 SP_DTR_FLOW_CONTROL = 2
186 /** DSR pin behaviour. */
188 /** Special value to indicate setting should be left alone. */
192 /** DSR used for flow control. */
193 SP_DSR_FLOW_CONTROL = 1
196 /** XON/XOFF flow control behaviour. */
198 /** Special value to indicate setting should be left alone. */
199 SP_XONXOFF_INVALID = -1,
200 /** XON/XOFF disabled. */
201 SP_XONXOFF_DISABLED = 0,
202 /** XON/XOFF enabled for input only. */
204 /** XON/XOFF enabled for output only. */
206 /** XON/XOFF enabled for input and output. */
210 /** Standard flow control combinations. */
211 enum sp_flowcontrol {
212 /** No flow control. */
213 SP_FLOWCONTROL_NONE = 0,
214 /** Software flow control using XON/XOFF characters. */
215 SP_FLOWCONTROL_XONXOFF = 1,
216 /** Hardware flow control using RTS/CTS signals. */
217 SP_FLOWCONTROL_RTSCTS = 2,
218 /** Hardware flow control using DTR/DSR signals. */
219 SP_FLOWCONTROL_DTRDSR = 3
222 /** Input signals. */
224 /** Clear to send. */
226 /** Data set ready. */
228 /** Data carrier detect. */
230 /** Ring indicator. */
240 /** Native platform serial port. @since 0.1.1 */
242 /** USB serial port adapter. @since 0.1.1 */
244 /** Bluetooth serial port adapter. @since 0.1.1 */
245 SP_TRANSPORT_BLUETOOTH
250 * An opaque structure representing a serial port.
255 * @struct sp_port_config
256 * An opaque structure representing the configuration for a serial port.
258 struct sp_port_config;
261 * @struct sp_event_set
262 * A set of handles to wait on for events.
264 struct sp_event_set {
265 /** Array of OS-specific handles. */
267 /** Array of bitmasks indicating which events apply for each handle. */
268 enum sp_event *masks;
269 /** Number of handles. */
274 * @defgroup Enumeration Port enumeration
276 * Enumerating the serial ports of a system.
282 * Obtain a pointer to a new sp_port structure representing the named port.
284 * The user should allocate a variable of type "struct sp_port *" and pass a
285 * pointer to this to receive the result.
287 * The result should be freed after use by calling sp_free_port().
289 * If any error is returned, the variable pointed to by port_ptr will be set
290 * to NULL. Otherwise, it will be set to point to the newly allocated port.
292 * @return SP_OK upon success, a negative error code otherwise.
296 enum sp_return sp_get_port_by_name(const char *portname, struct sp_port **port_ptr);
299 * Free a port structure obtained from sp_get_port_by_name() or sp_copy_port().
303 void sp_free_port(struct sp_port *port);
306 * List the serial ports available on the system.
308 * The result obtained is an array of pointers to sp_port structures,
309 * terminated by a NULL. The user should allocate a variable of type
310 * "struct sp_port **" and pass a pointer to this to receive the result.
312 * The result should be freed after use by calling sp_free_port_list().
313 * If a port from the list is to be used after freeing the list, it must be
314 * copied first using sp_copy_port().
316 * If any error is returned, the variable pointed to by list_ptr will be set
317 * to NULL. Otherwise, it will be set to point to the newly allocated array.
319 * @return SP_OK upon success, a negative error code otherwise.
323 enum sp_return sp_list_ports(struct sp_port ***list_ptr);
326 * Make a new copy of a sp_port structure.
328 * The user should allocate a variable of type "struct sp_port *" and pass a
329 * pointer to this to receive the result.
331 * The copy should be freed after use by calling sp_free_port().
333 * If any error is returned, the variable pointed to by copy_ptr will be set
334 * to NULL. Otherwise, it will be set to point to the newly allocated copy.
336 * @return SP_OK upon success, a negative error code otherwise.
340 enum sp_return sp_copy_port(const struct sp_port *port, struct sp_port **copy_ptr);
343 * Free a port list obtained from sp_list_ports().
345 * This will also free all the sp_port structures referred to from the list;
346 * any that are to be retained must be copied first using sp_copy_port().
350 void sp_free_port_list(struct sp_port **ports);
354 * @defgroup Ports Port handling
356 * Opening, closing and querying ports.
362 * Open the specified serial port.
364 * @param port Pointer to port structure.
365 * @param flags Flags to use when opening the serial port.
367 * @return SP_OK upon success, a negative error code otherwise.
371 enum sp_return sp_open(struct sp_port *port, enum sp_mode flags);
374 * Close the specified serial port.
376 * @return SP_OK upon success, a negative error code otherwise.
380 enum sp_return sp_close(struct sp_port *port);
383 * Get the name of a port.
385 * The name returned is whatever is normally used to refer to a port on the
386 * current operating system; e.g. for Windows it will usually be a "COMn"
387 * device name, and for Unix it will be a device path beginning with "/dev/".
389 * @param port Pointer to port structure.
391 * @return The port name, or NULL if an invalid port is passed. The name
392 * string is part of the port structure and may not be used after the
393 * port structure has been freed.
397 char *sp_get_port_name(const struct sp_port *port);
400 * Get a description for a port, to present to end user.
402 * @param port Pointer to port structure.
404 * @return The port description, or NULL if an invalid port is passed.
405 * The description string is part of the port structure and may not be used
406 * after the port structure has been freed.
410 char *sp_get_port_description(struct sp_port *port);
413 * Get the transport type used by a port.
415 * @param port Pointer to port structure.
417 * @return The port transport type.
421 enum sp_transport sp_get_port_transport(struct sp_port *port);
424 * Get the USB bus number and address on bus of a USB serial adapter port.
426 * @param port Pointer to port structure.
427 * @param usb_bus Pointer to variable to store USB bus.
428 * @param usb_address Pointer to variable to store USB address
430 * @return SP_OK upon success, a negative error code otherwise.
434 enum sp_return sp_get_port_usb_bus_address(const struct sp_port *port,
435 int *usb_bus, int *usb_address);
438 * Get the USB Vendor ID and Product ID of a USB serial adapter port.
440 * @param port Pointer to port structure.
441 * @param usb_vid Pointer to variable to store USB VID.
442 * @param usb_pid Pointer to variable to store USB PID
444 * @return SP_OK upon success, a negative error code otherwise.
448 enum sp_return sp_get_port_usb_vid_pid(const struct sp_port *port, int *usb_vid, int *usb_pid);
451 * Get the USB manufacturer string of a USB serial adapter port.
453 * @param port Pointer to port structure.
455 * @return The port manufacturer string, or NULL if an invalid port is passed.
456 * The manufacturer string is part of the port structure and may not be used
457 * after the port structure has been freed.
461 char *sp_get_port_usb_manufacturer(const struct sp_port *port);
464 * Get the USB product string of a USB serial adapter port.
466 * @param port Pointer to port structure.
468 * @return The port product string, or NULL if an invalid port is passed.
469 * The product string is part of the port structure and may not be used
470 * after the port structure has been freed.
474 char *sp_get_port_usb_product(const struct sp_port *port);
477 * Get the USB serial number string of a USB serial adapter port.
479 * @param port Pointer to port structure.
481 * @return The port serial number, or NULL if an invalid port is passed.
482 * The serial number string is part of the port structure and may not be used
483 * after the port structure has been freed.
487 char *sp_get_port_usb_serial(const struct sp_port *port);
490 * Get the MAC address of a Bluetooth serial adapter port.
492 * @param port Pointer to port structure.
494 * @return The port MAC address, or NULL if an invalid port is passed.
495 * The MAC address string is part of the port structure and may not be used
496 * after the port structure has been freed.
500 char *sp_get_port_bluetooth_address(const struct sp_port *port);
503 * Get the operating system handle for a port.
505 * The type of the handle depends on the operating system. On Unix based
506 * systems, the handle is a file descriptor of type "int". On Windows, the
507 * handle is of type "HANDLE". The user should allocate a variable of the
508 * appropriate type and pass a pointer to this to receive the result.
510 * To obtain a valid handle, the port must first be opened by calling
511 * sp_open() using the same port structure.
513 * After the port is closed or the port structure freed, the handle may
514 * no longer be valid.
516 * @warning This feature is provided so that programs may make use of
517 * OS-specific functionality where desired. Doing so obviously
518 * comes at a cost in portability. It also cannot be guaranteed
519 * that direct usage of the OS handle will not conflict with the
520 * library's own usage of the port. Be careful.
522 * @return SP_OK upon success, a negative error code otherwise.
526 enum sp_return sp_get_port_handle(const struct sp_port *port, void *result_ptr);
531 * @defgroup Configuration Configuration
533 * Setting and querying serial port parameters.
538 * Allocate a port configuration structure.
540 * The user should allocate a variable of type "struct sp_config *" and pass a
541 * pointer to this to receive the result. The variable will be updated to
542 * point to the new configuration structure. The structure is opaque and must
543 * be accessed via the functions provided.
545 * All parameters in the structure will be initialised to special values which
546 * are ignored by sp_set_config().
548 * The structure should be freed after use by calling sp_free_config().
550 * @param config_ptr Pointer to variable to receive result.
552 * @return SP_OK upon success, a negative error code otherwise.
556 enum sp_return sp_new_config(struct sp_port_config **config_ptr);
559 * Free a port configuration structure.
561 * @param config Pointer to configuration structure.
565 void sp_free_config(struct sp_port_config *config);
568 * Get the current configuration of the specified serial port.
570 * The user should allocate a configuration structure using sp_new_config()
571 * and pass this as the config parameter. The configuration structure will
572 * be updated with the port configuration.
574 * Any parameters that are configured with settings not recognised or
575 * supported by libserialport, will be set to special values that are
576 * ignored by sp_set_config().
578 * @return SP_OK upon success, a negative error code otherwise.
582 enum sp_return sp_get_config(struct sp_port *port, struct sp_port_config *config);
585 * Set the configuration for the specified serial port.
587 * For each parameter in the configuration, there is a special value (usually
588 * -1, but see the documentation for each field). These values will be ignored
589 * and the corresponding setting left unchanged on the port.
591 * @return SP_OK upon success, a negative error code otherwise.
595 enum sp_return sp_set_config(struct sp_port *port, const struct sp_port_config *config);
598 * Set the baud rate for the specified serial port.
600 * @param port Pointer to port structure.
601 * @param baudrate Baud rate in bits per second.
603 * @return SP_OK upon success, a negative error code otherwise.
607 enum sp_return sp_set_baudrate(struct sp_port *port, int baudrate);
610 * Get the baud rate from a port configuration.
612 * The user should allocate a variable of type int and pass a pointer to this
613 * to receive the result.
615 * @param config Pointer to configuration structure.
616 * @param baudrate_ptr Pointer to variable to store result.
618 * @return SP_OK upon success, a negative error code otherwise.
622 enum sp_return sp_get_config_baudrate(const struct sp_port_config *config, int *baudrate_ptr);
625 * Set the baud rate in a port configuration.
627 * @param config Pointer to configuration structure.
628 * @param baudrate Baud rate in bits per second, or -1 to retain current setting.
630 * @return SP_OK upon success, a negative error code otherwise.
634 enum sp_return sp_set_config_baudrate(struct sp_port_config *config, int baudrate);
637 * Set the data bits for the specified serial port.
639 * @param port Pointer to port structure.
640 * @param bits Number of data bits.
642 * @return SP_OK upon success, a negative error code otherwise.
646 enum sp_return sp_set_bits(struct sp_port *port, int bits);
649 * Get the data bits from a port configuration.
651 * The user should allocate a variable of type int and pass a pointer to this
652 * to receive the result.
654 * @param config Pointer to configuration structure.
655 * @param bits_ptr Pointer to variable to store result.
657 * @return SP_OK upon success, a negative error code otherwise.
661 enum sp_return sp_get_config_bits(const struct sp_port_config *config, int *bits_ptr);
664 * Set the data bits in a port configuration.
666 * @param config Pointer to configuration structure.
667 * @param bits Number of data bits, or -1 to retain current setting.
669 * @return SP_OK upon success, a negative error code otherwise.
673 enum sp_return sp_set_config_bits(struct sp_port_config *config, int bits);
676 * Set the parity setting for the specified serial port.
678 * @param port Pointer to port structure.
679 * @param parity Parity setting.
681 * @return SP_OK upon success, a negative error code otherwise.
685 enum sp_return sp_set_parity(struct sp_port *port, enum sp_parity parity);
688 * Get the parity setting from a port configuration.
690 * The user should allocate a variable of type enum sp_parity and pass a pointer to this
691 * to receive the result.
693 * @param config Pointer to configuration structure.
694 * @param parity_ptr Pointer to variable to store result.
696 * @return SP_OK upon success, a negative error code otherwise.
700 enum sp_return sp_get_config_parity(const struct sp_port_config *config, enum sp_parity *parity_ptr);
703 * Set the parity setting in a port configuration.
705 * @param config Pointer to configuration structure.
706 * @param parity Parity setting, or -1 to retain current setting.
708 * @return SP_OK upon success, a negative error code otherwise.
712 enum sp_return sp_set_config_parity(struct sp_port_config *config, enum sp_parity parity);
715 * Set the stop bits for the specified serial port.
717 * @param port Pointer to port structure.
718 * @param stopbits Number of stop bits.
720 * @return SP_OK upon success, a negative error code otherwise.
724 enum sp_return sp_set_stopbits(struct sp_port *port, int stopbits);
727 * Get the stop bits from a port configuration.
729 * The user should allocate a variable of type int and pass a pointer to this
730 * to receive the result.
732 * @param config Pointer to configuration structure.
733 * @param stopbits_ptr Pointer to variable to store result.
735 * @return SP_OK upon success, a negative error code otherwise.
739 enum sp_return sp_get_config_stopbits(const struct sp_port_config *config, int *stopbits_ptr);
742 * Set the stop bits in a port configuration.
744 * @param config Pointer to configuration structure.
745 * @param stopbits Number of stop bits, or -1 to retain current setting.
747 * @return SP_OK upon success, a negative error code otherwise.
751 enum sp_return sp_set_config_stopbits(struct sp_port_config *config, int stopbits);
754 * Set the RTS pin behaviour for the specified serial port.
756 * @param port Pointer to port structure.
757 * @param rts RTS pin mode.
759 * @return SP_OK upon success, a negative error code otherwise.
763 enum sp_return sp_set_rts(struct sp_port *port, enum sp_rts rts);
766 * Get the RTS pin behaviour from a port configuration.
768 * The user should allocate a variable of type enum sp_rts and pass a pointer to this
769 * to receive the result.
771 * @param config Pointer to configuration structure.
772 * @param rts_ptr Pointer to variable to store result.
774 * @return SP_OK upon success, a negative error code otherwise.
778 enum sp_return sp_get_config_rts(const struct sp_port_config *config, enum sp_rts *rts_ptr);
781 * Set the RTS pin behaviour in a port configuration.
783 * @param config Pointer to configuration structure.
784 * @param rts RTS pin mode, or -1 to retain current setting.
786 * @return SP_OK upon success, a negative error code otherwise.
790 enum sp_return sp_set_config_rts(struct sp_port_config *config, enum sp_rts rts);
793 * Set the CTS pin behaviour for the specified serial port.
795 * @param port Pointer to port structure.
796 * @param cts CTS pin mode.
798 * @return SP_OK upon success, a negative error code otherwise.
802 enum sp_return sp_set_cts(struct sp_port *port, enum sp_cts cts);
805 * Get the CTS pin behaviour from a port configuration.
807 * The user should allocate a variable of type enum sp_cts and pass a pointer to this
808 * to receive the result.
810 * @param config Pointer to configuration structure.
811 * @param cts_ptr Pointer to variable to store result.
813 * @return SP_OK upon success, a negative error code otherwise.
817 enum sp_return sp_get_config_cts(const struct sp_port_config *config, enum sp_cts *cts_ptr);
820 * Set the CTS pin behaviour in a port configuration.
822 * @param config Pointer to configuration structure.
823 * @param cts CTS pin mode, or -1 to retain current setting.
825 * @return SP_OK upon success, a negative error code otherwise.
829 enum sp_return sp_set_config_cts(struct sp_port_config *config, enum sp_cts cts);
832 * Set the DTR pin behaviour for the specified serial port.
834 * @param port Pointer to port structure.
835 * @param dtr DTR pin mode.
837 * @return SP_OK upon success, a negative error code otherwise.
841 enum sp_return sp_set_dtr(struct sp_port *port, enum sp_dtr dtr);
844 * Get the DTR pin behaviour from a port configuration.
846 * The user should allocate a variable of type enum sp_dtr and pass a pointer to this
847 * to receive the result.
849 * @param config Pointer to configuration structure.
850 * @param dtr_ptr Pointer to variable to store result.
852 * @return SP_OK upon success, a negative error code otherwise.
856 enum sp_return sp_get_config_dtr(const struct sp_port_config *config, enum sp_dtr *dtr_ptr);
859 * Set the DTR pin behaviour in a port configuration.
861 * @param config Pointer to configuration structure.
862 * @param dtr DTR pin mode, or -1 to retain current setting.
864 * @return SP_OK upon success, a negative error code otherwise.
868 enum sp_return sp_set_config_dtr(struct sp_port_config *config, enum sp_dtr dtr);
871 * Set the DSR pin behaviour for the specified serial port.
873 * @param port Pointer to port structure.
874 * @param dsr DSR pin mode.
876 * @return SP_OK upon success, a negative error code otherwise.
880 enum sp_return sp_set_dsr(struct sp_port *port, enum sp_dsr dsr);
883 * Get the DSR pin behaviour from a port configuration.
885 * The user should allocate a variable of type enum sp_dsr and pass a pointer to this
886 * to receive the result.
888 * @param config Pointer to configuration structure.
889 * @param dsr_ptr Pointer to variable to store result.
891 * @return SP_OK upon success, a negative error code otherwise.
895 enum sp_return sp_get_config_dsr(const struct sp_port_config *config, enum sp_dsr *dsr_ptr);
898 * Set the DSR pin behaviour in a port configuration.
900 * @param config Pointer to configuration structure.
901 * @param dsr DSR pin mode, or -1 to retain current setting.
903 * @return SP_OK upon success, a negative error code otherwise.
907 enum sp_return sp_set_config_dsr(struct sp_port_config *config, enum sp_dsr dsr);
910 * Set the XON/XOFF configuration for the specified serial port.
912 * @param port Pointer to port structure.
913 * @param xon_xoff XON/XOFF mode.
915 * @return SP_OK upon success, a negative error code otherwise.
919 enum sp_return sp_set_xon_xoff(struct sp_port *port, enum sp_xonxoff xon_xoff);
922 * Get the XON/XOFF configuration from a port configuration.
924 * The user should allocate a variable of type enum sp_xonxoff and pass a pointer to this
925 * to receive the result.
927 * @param config Pointer to configuration structure.
928 * @param xon_xoff_ptr Pointer to variable to store result.
930 * @return SP_OK upon success, a negative error code otherwise.
934 enum sp_return sp_get_config_xon_xoff(const struct sp_port_config *config, enum sp_xonxoff *xon_xoff_ptr);
937 * Set the XON/XOFF configuration in a port configuration.
939 * @param config Pointer to configuration structure.
940 * @param xon_xoff XON/XOFF mode, or -1 to retain current setting.
942 * @return SP_OK upon success, a negative error code otherwise.
946 enum sp_return sp_set_config_xon_xoff(struct sp_port_config *config, enum sp_xonxoff xon_xoff);
949 * Set the flow control type in a port configuration.
951 * This function is a wrapper that sets the RTS, CTS, DTR, DSR and
952 * XON/XOFF settings as necessary for the specified flow control
953 * type. For more fine-grained control of these settings, use their
954 * individual configuration functions.
956 * @param config Pointer to configuration structure.
957 * @param flowcontrol Flow control setting to use.
959 * @return SP_OK upon success, a negative error code otherwise.
963 enum sp_return sp_set_config_flowcontrol(struct sp_port_config *config, enum sp_flowcontrol flowcontrol);
966 * Set the flow control type for the specified serial port.
968 * This function is a wrapper that sets the RTS, CTS, DTR, DSR and
969 * XON/XOFF settings as necessary for the specified flow control
970 * type. For more fine-grained control of these settings, use their
971 * individual configuration functions.
973 * @param port Pointer to port structure.
974 * @param flowcontrol Flow control setting to use.
976 * @return SP_OK upon success, a negative error code otherwise.
980 enum sp_return sp_set_flowcontrol(struct sp_port *port, enum sp_flowcontrol flowcontrol);
985 * @defgroup Data Data handling
987 * Reading, writing, and flushing data.
993 * Read bytes from the specified serial port, blocking until complete.
995 * @warning If your program runs on Unix, defines its own signal handlers, and
996 * needs to abort blocking reads when these are called, then you
997 * should not use this function. It repeats system calls that return
998 * with EINTR. To be able to abort a read from a signal handler, you
999 * should implement your own blocking read using sp_nonblocking_read()
1000 * together with a blocking method that makes sense for your program.
1001 * E.g. you can obtain the file descriptor for an open port using
1002 * sp_get_port_handle() and use this to call select() or pselect(),
1003 * with appropriate arrangements to return if a signal is received.
1005 * @param port Pointer to port structure.
1006 * @param buf Buffer in which to store the bytes read.
1007 * @param count Requested number of bytes to read.
1008 * @param timeout Timeout in milliseconds, or zero to wait indefinitely.
1010 * @return The number of bytes read on success, or a negative error code. If
1011 * the number of bytes returned is less than that requested, the
1012 * timeout was reached before the requested number of bytes was
1013 * available. If timeout is zero, the function will always return
1014 * either the requested number of bytes or a negative error code.
1018 enum sp_return sp_blocking_read(struct sp_port *port, void *buf, size_t count, unsigned int timeout);
1021 * Read bytes from the specified serial port, without blocking.
1023 * @param port Pointer to port structure.
1024 * @param buf Buffer in which to store the bytes read.
1025 * @param count Maximum number of bytes to read.
1027 * @return The number of bytes read on success, or a negative error code. The
1028 * number of bytes returned may be any number from zero to the maximum
1029 * that was requested.
1033 enum sp_return sp_nonblocking_read(struct sp_port *port, void *buf, size_t count);
1036 * Write bytes to the specified serial port, blocking until complete.
1038 * Note that this function only ensures that the accepted bytes have been
1039 * written to the OS; they may be held in driver or hardware buffers and not
1040 * yet physically transmitted. To check whether all written bytes have actually
1041 * been transmitted, use the sp_output_waiting() function. To wait until all
1042 * written bytes have actually been transmitted, use the sp_drain() function.
1044 * @warning If your program runs on Unix, defines its own signal handlers, and
1045 * needs to abort blocking writes when these are called, then you
1046 * should not use this function. It repeats system calls that return
1047 * with EINTR. To be able to abort a write from a signal handler, you
1048 * should implement your own blocking write using sp_nonblocking_write()
1049 * together with a blocking method that makes sense for your program.
1050 * E.g. you can obtain the file descriptor for an open port using
1051 * sp_get_port_handle() and use this to call select() or pselect(),
1052 * with appropriate arrangements to return if a signal is received.
1054 * @param port Pointer to port structure.
1055 * @param buf Buffer containing the bytes to write.
1056 * @param count Requested number of bytes to write.
1057 * @param timeout Timeout in milliseconds, or zero to wait indefinitely.
1059 * @return The number of bytes written on success, or a negative error code.
1060 * If the number of bytes returned is less than that requested, the
1061 * timeout was reached before the requested number of bytes was
1062 * written. If timeout is zero, the function will always return
1063 * either the requested number of bytes or a negative error code. In
1064 * the event of an error there is no way to determine how many bytes
1065 * were sent before the error occurred.
1069 enum sp_return sp_blocking_write(struct sp_port *port, const void *buf, size_t count, unsigned int timeout);
1072 * Write bytes to the specified serial port, without blocking.
1074 * Note that this function only ensures that the accepted bytes have been
1075 * written to the OS; they may be held in driver or hardware buffers and not
1076 * yet physically transmitted. To check whether all written bytes have actually
1077 * been transmitted, use the sp_output_waiting() function. To wait until all
1078 * written bytes have actually been transmitted, use the sp_drain() function.
1080 * @param port Pointer to port structure.
1081 * @param buf Buffer containing the bytes to write.
1082 * @param count Maximum number of bytes to write.
1084 * @return The number of bytes written on success, or a negative error code.
1085 * The number of bytes returned may be any number from zero to the
1086 * maximum that was requested.
1090 enum sp_return sp_nonblocking_write(struct sp_port *port, const void *buf, size_t count);
1093 * Gets the number of bytes waiting in the input buffer.
1095 * @param port Pointer to port structure.
1097 * @return Number of bytes waiting on success, a negative error code otherwise.
1101 enum sp_return sp_input_waiting(struct sp_port *port);
1104 * Gets the number of bytes waiting in the output buffer.
1106 * @param port Pointer to port structure.
1108 * @return Number of bytes waiting on success, a negative error code otherwise.
1112 enum sp_return sp_output_waiting(struct sp_port *port);
1115 * Flush serial port buffers. Data in the selected buffer(s) is discarded.
1117 * @param port Pointer to port structure.
1118 * @param buffers Which buffer(s) to flush.
1120 * @return SP_OK upon success, a negative error code otherwise.
1124 enum sp_return sp_flush(struct sp_port *port, enum sp_buffer buffers);
1127 * Wait for buffered data to be transmitted.
1129 * @warning If your program runs on Unix, defines its own signal handlers, and
1130 * needs to abort draining the output buffer when when these are
1131 * called, then you should not use this function. It repeats system
1132 * calls that return with EINTR. To be able to abort a drain from a
1133 * signal handler, you would need to implement your own blocking
1134 * drain by polling the result of sp_output_waiting().
1136 * @param port Pointer to port structure.
1138 * @return SP_OK upon success, a negative error code otherwise.
1142 enum sp_return sp_drain(struct sp_port *port);
1147 * @defgroup Waiting Waiting
1149 * Waiting for events and timeout handling.
1155 * Allocate storage for a set of events.
1157 * The user should allocate a variable of type struct sp_event_set *,
1158 * then pass a pointer to this variable to receive the result.
1160 * The result should be freed after use by calling sp_free_event_set().
1162 * @return SP_OK upon success, a negative error code otherwise.
1166 enum sp_return sp_new_event_set(struct sp_event_set **result_ptr);
1169 * Add events to a struct sp_event_set for a given port.
1171 * The port must first be opened by calling sp_open() using the same port
1174 * After the port is closed or the port structure freed, the results may
1175 * no longer be valid.
1177 * @param event_set Event set to update.
1178 * @param port Pointer to port structure.
1179 * @param mask Bitmask of events to be waited for.
1181 * @return SP_OK upon success, a negative error code otherwise.
1185 enum sp_return sp_add_port_events(struct sp_event_set *event_set,
1186 const struct sp_port *port, enum sp_event mask);
1189 * Wait for any of a set of events to occur.
1191 * @param event_set Event set to wait on.
1192 * @param timeout Timeout in milliseconds, or zero to wait indefinitely.
1194 * @return SP_OK upon success, a negative error code otherwise.
1198 enum sp_return sp_wait(struct sp_event_set *event_set, unsigned int timeout);
1201 * Free a structure allocated by sp_new_event_set().
1205 void sp_free_event_set(struct sp_event_set *event_set);
1210 * @defgroup Signals Signals
1212 * Port signalling operations.
1218 * Gets the status of the control signals for the specified port.
1220 * The user should allocate a variable of type "enum sp_signal" and pass a
1221 * pointer to this variable to receive the result. The result is a bitmask
1222 * in which individual signals can be checked by bitwise OR with values of
1223 * the sp_signal enum.
1225 * @param port Pointer to port structure.
1226 * @param signal_mask Pointer to variable to receive result.
1228 * @return SP_OK upon success, a negative error code otherwise.
1232 enum sp_return sp_get_signals(struct sp_port *port, enum sp_signal *signal_mask);
1235 * Put the port transmit line into the break state.
1237 * @param port Pointer to port structure.
1239 * @return SP_OK upon success, a negative error code otherwise.
1243 enum sp_return sp_start_break(struct sp_port *port);
1246 * Take the port transmit line out of the break state.
1248 * @param port Pointer to port structure.
1250 * @return SP_OK upon success, a negative error code otherwise.
1254 enum sp_return sp_end_break(struct sp_port *port);
1259 * @defgroup Errors Errors
1261 * Obtaining error information.
1267 * Get the error code for a failed operation.
1269 * In order to obtain the correct result, this function should be called
1270 * straight after the failure, before executing any other system operations.
1272 * @return The system's numeric code for the error that caused the last
1273 * operation to fail.
1277 int sp_last_error_code(void);
1280 * Get the error message for a failed operation.
1282 * In order to obtain the correct result, this function should be called
1283 * straight after the failure, before executing other system operations.
1285 * @return The system's message for the error that caused the last
1286 * operation to fail. This string may be allocated by the function,
1287 * and should be freed after use by calling sp_free_error_message().
1291 char *sp_last_error_message(void);
1294 * Free an error message returned by sp_last_error_message().
1298 void sp_free_error_message(char *message);
1301 * Set the handler function for library debugging messages.
1303 * Debugging messages are generated by the library during each operation,
1304 * to help in diagnosing problems. The handler will be called for each
1305 * message. The handler can be set to NULL to ignore all debug messages.
1307 * The handler function should accept a format string and variable length
1308 * argument list, in the same manner as e.g. printf().
1310 * The default handler is sp_default_debug_handler().
1314 void sp_set_debug_handler(void (*handler)(const char *format, ...));
1317 * Default handler function for library debugging messages.
1319 * This function prints debug messages to the standard error stream if the
1320 * environment variable LIBSERIALPORT_DEBUG is set. Otherwise, they are
1325 void sp_default_debug_handler(const char *format, ...);
1330 * @defgroup Versions Versions
1332 * Version number querying functions, definitions, and macros.
1334 * This set of API calls returns two different version numbers related
1335 * to libserialport. The "package version" is the release version number of the
1336 * libserialport tarball in the usual "major.minor.micro" format, e.g. "0.1.0".
1338 * The "library version" is independent of that; it is the libtool version
1339 * number in the "current:revision:age" format, e.g. "2:0:0".
1340 * See http://www.gnu.org/software/libtool/manual/libtool.html#Libtool-versioning for details.
1342 * Both version numbers (and/or individual components of them) can be
1343 * retrieved via the API calls at runtime, and/or they can be checked at
1344 * compile/preprocessor time using the respective macros.
1350 * Package version macros (can be used for conditional compilation).
1353 /** The libserialport package 'major' version number. */
1354 #define SP_PACKAGE_VERSION_MAJOR @SP_PACKAGE_VERSION_MAJOR@
1356 /** The libserialport package 'minor' version number. */
1357 #define SP_PACKAGE_VERSION_MINOR @SP_PACKAGE_VERSION_MINOR@
1359 /** The libserialport package 'micro' version number. */
1360 #define SP_PACKAGE_VERSION_MICRO @SP_PACKAGE_VERSION_MICRO@
1362 /** The libserialport package version ("major.minor.micro") as string. */
1363 #define SP_PACKAGE_VERSION_STRING "@SP_PACKAGE_VERSION@"
1366 * Library/libtool version macros (can be used for conditional compilation).
1369 /** The libserialport libtool 'current' version number. */
1370 #define SP_LIB_VERSION_CURRENT @SP_LIB_VERSION_CURRENT@
1372 /** The libserialport libtool 'revision' version number. */
1373 #define SP_LIB_VERSION_REVISION @SP_LIB_VERSION_REVISION@
1375 /** The libserialport libtool 'age' version number. */
1376 #define SP_LIB_VERSION_AGE @SP_LIB_VERSION_AGE@
1378 /** The libserialport libtool version ("current:revision:age") as string. */
1379 #define SP_LIB_VERSION_STRING "@SP_LIB_VERSION@"
1382 * Get the major libserialport package version number.
1384 * @return The major package version number.
1388 int sp_get_major_package_version(void);
1391 * Get the minor libserialport package version number.
1393 * @return The minor package version number.
1397 int sp_get_minor_package_version(void);
1400 * Get the micro libserialport package version number.
1402 * @return The micro package version number.
1406 int sp_get_micro_package_version(void);
1409 * Get the libserialport package version number as a string.
1411 * @return The package version number string. The returned string is
1412 * static and thus should NOT be free'd by the caller.
1416 const char *sp_get_package_version_string(void);
1419 * Get the "current" part of the libserialport library version number.
1421 * @return The "current" library version number.
1425 int sp_get_current_lib_version(void);
1428 * Get the "revision" part of the libserialport library version number.
1430 * @return The "revision" library version number.
1434 int sp_get_revision_lib_version(void);
1437 * Get the "age" part of the libserialport library version number.
1439 * @return The "age" library version number.
1443 int sp_get_age_lib_version(void);
1446 * Get the libserialport library version number as a string.
1448 * @return The library version number string. The returned string is
1449 * static and thus should NOT be free'd by the caller.
1453 const char *sp_get_lib_version_string(void);