libserialport.h.in

   1 /*
   2  * This file is part of the libserialport project.
   3  *
   4  * Copyright (C) 2013 Martin Ling <martin-libserialport@earth.li>
   5  *
   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.
  10  *
  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.
  15  *
  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/>.
  18  */
  19
  20 /**
  21  * @mainpage libserialport API
  22  *
  23  * Introduction
  24  * ============
  25  *
  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.
  28  *
  29  * By writing your serial code to use libserialport, you enable it to work
  30  * transparently on any platform supported by the library.
  31  *
  32  * The operations that are supported are:
  33  *
  34  * - @ref Enumeration (obtaining a list of serial ports on the system)
  35  * - @ref Ports
  36  * - @ref Configuration (baud rate, parity, etc.)
  37  * - @ref Signals (modem control lines, breaks, etc.)
  38  * - @ref Data
  39  * - @ref Waiting
  40  * - @ref Errors
  41  *
  42  * libserialport is an open source project released under the LGPL3+ license.
  43  *
  44  * API principles
  45  * ==============
  46  *
  47  * The API is simple, and designed to be a minimal wrapper around the serial
  48  * port support in each OS.
  49  *
  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.
  53  *
  54  * Most functions have return type @ref sp_return and can return only four
  55  * possible error values:
  56  *
  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.
  60  *
  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().
  64  *
  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.
  70  *
  71  * - @ref SP_ERR_MEM indicates that a memory allocation failed.
  72  *
  73  * All of these error values are negative.
  74  *
  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().
  78  */
  79
  80 #ifndef LIBSERIALPORT_LIBSERIALPORT_H
  81 #define LIBSERIALPORT_LIBSERIALPORT_H
  82
  83 #ifdef __cplusplus
  84 extern "C" {
  85 #endif
  86
  87 #include <stddef.h>
  88 #ifdef _WIN32
  89 #include <windows.h>
  90 #endif
  91
  92 /** Return values. */
  93 enum sp_return {
  94         /** Operation completed successfully. */
  95         SP_OK = 0,
  96         /** Invalid arguments were passed to the function. */
  97         SP_ERR_ARG = -1,
  98         /** A system error occured while executing the operation. */
  99         SP_ERR_FAIL = -2,
 100         /** A memory allocation failed while executing the operation. */
 101         SP_ERR_MEM = -3,
 102         /** The requested operation is not supported by this system or device. */
 103         SP_ERR_SUPP = -4,
 104 };
 105
 106 /** Port access modes. */
 107 enum sp_mode {
 108         /** Open port for read access. */
 109         SP_MODE_READ = 1,
 110         /** Open port for write access. */
 111         SP_MODE_WRITE = 2,
 112 };
 113
 114 /** Port events. */
 115 enum sp_event {
 116         /* Data received and ready to read. */
 117         SP_EVENT_RX_READY = 1,
 118         /* Ready to transmit new data. */
 119         SP_EVENT_TX_READY = 2,
 120         /* Error occured. */
 121         SP_EVENT_ERROR = 4,
 122 };
 123
 124 /** Buffer selection. */
 125 enum sp_buffer {
 126         /** Input buffer. */
 127         SP_BUF_INPUT = 1,
 128         /** Output buffer. */
 129         SP_BUF_OUTPUT = 2,
 130         /** Both buffers. */
 131         SP_BUF_BOTH = 3,
 132 };
 133
 134 /** Parity settings. */
 135 enum sp_parity {
 136         /** Special value to indicate setting should be left alone. */
 137         SP_PARITY_INVALID = -1,
 138         /** No parity. */
 139         SP_PARITY_NONE = 0,
 140         /** Odd parity. */
 141         SP_PARITY_ODD = 1,
 142         /** Even parity. */
 143         SP_PARITY_EVEN = 2,
 144         /** Mark parity. */
 145         SP_PARITY_MARK = 3,
 146         /** Space parity. */
 147         SP_PARITY_SPACE = 4,
 148 };
 149
 150 /** RTS pin behaviour. */
 151 enum sp_rts {
 152         /** Special value to indicate setting should be left alone. */
 153         SP_RTS_INVALID = -1,
 154         /** RTS off. */
 155         SP_RTS_OFF = 0,
 156         /** RTS on. */
 157         SP_RTS_ON = 1,
 158         /** RTS used for flow control. */
 159         SP_RTS_FLOW_CONTROL = 2,
 160 };
 161
 162 /** CTS pin behaviour. */
 163 enum sp_cts {
 164         /** Special value to indicate setting should be left alone. */
 165         SP_CTS_INVALID = -1,
 166         /** CTS ignored. */
 167         SP_CTS_IGNORE = 0,
 168         /** CTS used for flow control. */
 169         SP_CTS_FLOW_CONTROL = 1,
 170 };
 171
 172 /** DTR pin behaviour. */
 173 enum sp_dtr {
 174         /** Special value to indicate setting should be left alone. */
 175         SP_DTR_INVALID = -1,
 176         /** DTR off. */
 177         SP_DTR_OFF = 0,
 178         /** DTR on. */
 179         SP_DTR_ON = 1,
 180         /** DTR used for flow control. */
 181         SP_DTR_FLOW_CONTROL = 2,
 182 };
 183
 184 /** DSR pin behaviour. */
 185 enum sp_dsr {
 186         /** Special value to indicate setting should be left alone. */
 187         SP_DSR_INVALID = -1,
 188         /** DSR ignored. */
 189         SP_DSR_IGNORE = 0,
 190         /** DSR used for flow control. */
 191         SP_DSR_FLOW_CONTROL = 1,
 192 };
 193
 194 /** XON/XOFF flow control behaviour. */
 195 enum sp_xonxoff {
 196         /** Special value to indicate setting should be left alone. */
 197         SP_XONXOFF_INVALID = -1,
 198         /** XON/XOFF disabled. */
 199         SP_XONXOFF_DISABLED = 0,
 200         /** XON/XOFF enabled for input only. */
 201         SP_XONXOFF_IN = 1,
 202         /** XON/XOFF enabled for output only. */
 203         SP_XONXOFF_OUT = 2,
 204         /** XON/XOFF enabled for input and output. */
 205         SP_XONXOFF_INOUT = 3,
 206 };
 207
 208 /** Standard flow control combinations. */
 209 enum sp_flowcontrol {
 210         /** No flow control. */
 211         SP_FLOWCONTROL_NONE = 0,
 212         /** Software flow control using XON/XOFF characters. */
 213         SP_FLOWCONTROL_XONXOFF = 1,
 214         /** Hardware flow control using RTS/CTS signals. */
 215         SP_FLOWCONTROL_RTSCTS = 2,
 216         /** Hardware flow control using DTR/DSR signals. */
 217         SP_FLOWCONTROL_DTRDSR = 3,
 218 };
 219
 220 /** Input signals. */
 221 enum sp_signal {
 222         /** Clear to send. */
 223         SP_SIG_CTS = 1,
 224         /** Data set ready. */
 225         SP_SIG_DSR = 2,
 226         /** Data carrier detect. */
 227         SP_SIG_DCD = 4,
 228         /** Ring indicator. */
 229         SP_SIG_RI = 8,
 230 };
 231
 232 /**
 233  * @struct sp_port
 234  * An opaque structure representing a serial port.
 235  */
 236 struct sp_port;
 237
 238 /**
 239  * @struct sp_port_config
 240  * An opaque structure representing the configuration for a serial port.
 241  */
 242 struct sp_port_config;
 243
 244 /**
 245  * @struct sp_event_set
 246  * A set of handles to wait on for events.
 247  */
 248 struct sp_event_set {
 249         /** Array of OS-specific handles. */
 250         void *handles;
 251         /** Array of bitmasks indicating which events apply for each handle. */
 252         enum sp_event *masks;
 253         /** Number of handles. */
 254         unsigned int count;
 255 };
 256
 257 /**
 258 @defgroup Enumeration Port enumeration
 259 @{
 260 */
 261
 262 /**
 263  * Obtain a pointer to a new sp_port structure representing the named port.
 264  *
 265  * The user should allocate a variable of type "struct sp_port *" and pass a
 266  * pointer to this to receive the result.
 267  *
 268  * The result should be freed after use by calling sp_free_port().
 269  *
 270  * If any error is returned, the variable pointed to by port_ptr will be set
 271  * to NULL. Otherwise, it will be set to point to the newly allocated port.
 272  *
 273  * @return SP_OK upon success, a negative error code otherwise.
 274  *
 275  * @since 0.1.0
 276  */
 277 enum sp_return sp_get_port_by_name(const char *portname, struct sp_port **port_ptr);
 278
 279 /**
 280  * Free a port structure obtained from sp_get_port_by_name() or sp_copy_port().
 281  *
 282  * @since 0.1.0
 283  */
 284 void sp_free_port(struct sp_port *port);
 285
 286 /**
 287  * List the serial ports available on the system.
 288  *
 289  * The result obtained is an array of pointers to sp_port structures,
 290  * terminated by a NULL. The user should allocate a variable of type
 291  * "struct sp_port **" and pass a pointer to this to receive the result.
 292  *
 293  * The result should be freed after use by calling sp_free_port_list().
 294  * If a port from the list is to be used after freeing the list, it must be
 295  * copied first using sp_copy_port().
 296  *
 297  * If any error is returned, the variable pointed to by list_ptr will be set
 298  * to NULL. Otherwise, it will be set to point to the newly allocated array.
 299  *
 300  * @return SP_OK upon success, a negative error code otherwise.
 301  *
 302  * @since 0.1.0
 303  */
 304 enum sp_return sp_list_ports(struct sp_port ***list_ptr);
 305
 306 /**
 307  * Make a new copy of a sp_port structure.
 308  *
 309  * The user should allocate a variable of type "struct sp_port *" and pass a
 310  * pointer to this to receive the result.
 311  *
 312  * The copy should be freed after use by calling sp_free_port().
 313  *
 314  * If any error is returned, the variable pointed to by copy_ptr will be set
 315  * to NULL. Otherwise, it will be set to point to the newly allocated copy.
 316  *
 317  * @return SP_OK upon success, a negative error code otherwise.
 318  *
 319  * @since 0.1.0
 320  */
 321 enum sp_return sp_copy_port(const struct sp_port *port, struct sp_port **copy_ptr);
 322
 323 /**
 324  * Free a port list obtained from sp_list_ports().
 325  *
 326  * This will also free all the sp_port structures referred to from the list;
 327  * any that are to be retained must be copied first using sp_copy_port().
 328  *
 329  * @since 0.1.0
 330  */
 331 void sp_free_port_list(struct sp_port **ports);
 332
 333 /**
 334  * @}
 335  * @defgroup Ports Opening, closing and querying ports
 336  * @{
 337  */
 338
 339 /**
 340  * Open the specified serial port.
 341  *
 342  * @param port Pointer to port structure.
 343  * @param flags Flags to use when opening the serial port.
 344  *
 345  * @return SP_OK upon success, a negative error code otherwise.
 346  *
 347  * @since 0.1.0
 348  */
 349 enum sp_return sp_open(struct sp_port *port, enum sp_mode flags);
 350
 351 /**
 352  * Close the specified serial port.
 353  *
 354  * @return SP_OK upon success, a negative error code otherwise.
 355  *
 356  * @since 0.1.0
 357  */
 358 enum sp_return sp_close(struct sp_port *port);
 359
 360 /**
 361  * Get the name of a port.
 362  *
 363  * The name returned is whatever is normally used to refer to a port on the
 364  * current operating system; e.g. for Windows it will usually be a "COMn"
 365  * device name, and for Unix it will be a device path beginning with "/dev/".
 366  *
 367  * @param port Pointer to port structure.
 368  *
 369  * @return The port name, or NULL if an invalid port is passed. The name
 370  * string is part of the port structure and may not be used after the
 371  * port structure has been freed.
 372  *
 373  * @since 0.1.0
 374  */
 375 char *sp_get_port_name(const struct sp_port *port);
 376
 377 /**
 378  * Get the operating system handle for a port.
 379  *
 380  * The type of the handle depends on the operating system. On Unix based
 381  * systems, the handle is a file descriptor of type "int". On Windows, the
 382  * handle is of type "HANDLE". The user should allocate a variable of the
 383  * appropriate type and pass a pointer to this to receive the result.
 384  *
 385  * To obtain a valid handle, the port must first be opened by calling
 386  * sp_open() using the same port structure.
 387  *
 388  * After the port is closed or the port structure freed, the handle may
 389  * no longer be valid.
 390  *
 391  * @warning This feature is provided so that programs may make use of
 392  *          OS-specific functionality where desired. Doing so obviously
 393  *          comes at a cost in portability. It also cannot be guaranteed
 394  *          that direct usage of the OS handle will not conflict with the
 395  *          library's own usage of the port. Be careful.
 396  *
 397  * @return SP_OK upon success, a negative error code otherwise.
 398  *
 399  * @since 0.1.0
 400  */
 401 enum sp_return sp_get_port_handle(const struct sp_port *port, void *result_ptr);
 402
 403 /**
 404  * @}
 405  * @defgroup Configuration Setting port parameters
 406  * @{
 407  */
 408
 409 /**
 410  * Allocate a port configuration structure.
 411  *
 412  * The user should allocate a variable of type "struct sp_config *" and pass a
 413  * pointer to this to receive the result. The variable will be updated to
 414  * point to the new configuration structure. The structure is opaque and must
 415  * be accessed via the functions provided.
 416  *
 417  * All parameters in the structure will be initialised to special values which
 418  * are ignored by sp_set_config().
 419  *
 420  * The structure should be freed after use by calling sp_free_config().
 421  *
 422  * @param config_ptr Pointer to variable to receive result.
 423  *
 424  * @return SP_OK upon success, a negative error code otherwise.
 425  *
 426  * @since 0.1.0
 427  */
 428 enum sp_return sp_new_config(struct sp_port_config **config_ptr);
 429
 430 /**
 431  * Free a port configuration structure.
 432  *
 433  * @param config Pointer to configuration structure.
 434  *
 435  * @since 0.1.0
 436  */
 437 void sp_free_config(struct sp_port_config *config);
 438
 439 /**
 440  * Get the current configuration of the specified serial port.
 441  *
 442  * The user should allocate a configuration structure using sp_new_config()
 443  * and pass this as the config parameter. The configuration structure will
 444  * be updated with the port configuration.
 445  *
 446  * Any parameters that are configured with settings not recognised or
 447  * supported by libserialport, will be set to special values that are
 448  * ignored by sp_set_config().
 449  *
 450  * @return SP_OK upon success, a negative error code otherwise.
 451  *
 452  * @since 0.1.0
 453  */
 454 enum sp_return sp_get_config(struct sp_port *port, struct sp_port_config *config);
 455
 456 /**
 457  * Set the configuration for the specified serial port.
 458  *
 459  * For each parameter in the configuration, there is a special value (usually
 460  * -1, but see the documentation for each field). These values will be ignored
 461  * and the corresponding setting left unchanged on the port.
 462  *
 463  * @return SP_OK upon success, a negative error code otherwise.
 464  *
 465  * @since 0.1.0
 466  */
 467 enum sp_return sp_set_config(struct sp_port *port, const struct sp_port_config *config);
 468
 469 /**
 470  * Set the baud rate for the specified serial port.
 471  *
 472  * @param port Pointer to port structure.
 473  * @param baudrate Baud rate in bits per second.
 474  *
 475  * @return SP_OK upon success, a negative error code otherwise.
 476  *
 477  * @since 0.1.0
 478  */
 479 enum sp_return sp_set_baudrate(struct sp_port *port, int baudrate);
 480
 481 /**
 482  * Get the baud rate from a port configuration.
 483  *
 484  * The user should allocate a variable of type int and pass a pointer to this
 485  * to receive the result.
 486  *
 487  * @param config Pointer to configuration structure.
 488  * @param baudrate_ptr Pointer to variable to store result.
 489  *
 490  * @return SP_OK upon success, a negative error code otherwise.
 491  *
 492  * @since 0.1.0
 493  */
 494 enum sp_return sp_get_config_baudrate(const struct sp_port_config *config, int *baudrate_ptr);
 495
 496 /**
 497  * Set the baud rate in a port configuration.
 498  *
 499  * @param config Pointer to configuration structure.
 500  * @param baudrate Baud rate in bits per second, or -1 to retain current setting.
 501  *
 502  * @return SP_OK upon success, a negative error code otherwise.
 503  *
 504  * @since 0.1.0
 505  */
 506 enum sp_return sp_set_config_baudrate(struct sp_port_config *config, int baudrate);
 507
 508 /**
 509  * Set the data bits for the specified serial port.
 510  *
 511  * @param port Pointer to port structure.
 512  * @param bits Number of data bits.
 513  *
 514  * @return SP_OK upon success, a negative error code otherwise.
 515  *
 516  * @since 0.1.0
 517  */
 518 enum sp_return sp_set_bits(struct sp_port *port, int bits);
 519
 520 /**
 521  * Get the data bits from a port configuration.
 522  *
 523  * The user should allocate a variable of type int and pass a pointer to this
 524  * to receive the result.
 525  *
 526  * @param config Pointer to configuration structure.
 527  * @param bits_ptr Pointer to variable to store result.
 528  *
 529  * @return SP_OK upon success, a negative error code otherwise.
 530  *
 531  * @since 0.1.0
 532  */
 533 enum sp_return sp_get_config_bits(const struct sp_port_config *config, int *bits_ptr);
 534
 535 /**
 536  * Set the data bits in a port configuration.
 537  *
 538  * @param config Pointer to configuration structure.
 539  * @param bits Number of data bits, or -1 to retain current setting.
 540  *
 541  * @return SP_OK upon success, a negative error code otherwise.
 542  *
 543  * @since 0.1.0
 544  */
 545 enum sp_return sp_set_config_bits(struct sp_port_config *config, int bits);
 546
 547 /**
 548  * Set the parity setting for the specified serial port.
 549  *
 550  * @param port Pointer to port structure.
 551  * @param parity Parity setting.
 552  *
 553  * @return SP_OK upon success, a negative error code otherwise.
 554  *
 555  * @since 0.1.0
 556  */
 557 enum sp_return sp_set_parity(struct sp_port *port, enum sp_parity parity);
 558
 559 /**
 560  * Get the parity setting from a port configuration.
 561  *
 562  * The user should allocate a variable of type enum sp_parity and pass a pointer to this
 563  * to receive the result.
 564  *
 565  * @param config Pointer to configuration structure.
 566  * @param parity_ptr Pointer to variable to store result.
 567  *
 568  * @return SP_OK upon success, a negative error code otherwise.
 569  *
 570  * @since 0.1.0
 571  */
 572 enum sp_return sp_get_config_parity(const struct sp_port_config *config, enum sp_parity *parity_ptr);
 573
 574 /**
 575  * Set the parity setting in a port configuration.
 576  *
 577  * @param config Pointer to configuration structure.
 578  * @param parity Parity setting, or -1 to retain current setting.
 579  *
 580  * @return SP_OK upon success, a negative error code otherwise.
 581  *
 582  * @since 0.1.0
 583  */
 584 enum sp_return sp_set_config_parity(struct sp_port_config *config, enum sp_parity parity);
 585
 586 /**
 587  * Set the stop bits for the specified serial port.
 588  *
 589  * @param port Pointer to port structure.
 590  * @param stopbits Number of stop bits.
 591  *
 592  * @return SP_OK upon success, a negative error code otherwise.
 593  *
 594  * @since 0.1.0
 595  */
 596 enum sp_return sp_set_stopbits(struct sp_port *port, int stopbits);
 597
 598 /**
 599  * Get the stop bits from a port configuration.
 600  *
 601  * The user should allocate a variable of type int and pass a pointer to this
 602  * to receive the result.
 603  *
 604  * @param config Pointer to configuration structure.
 605  * @param stopbits_ptr Pointer to variable to store result.
 606  *
 607  * @return SP_OK upon success, a negative error code otherwise.
 608  *
 609  * @since 0.1.0
 610  */
 611 enum sp_return sp_get_config_stopbits(const struct sp_port_config *config, int *stopbits_ptr);
 612
 613 /**
 614  * Set the stop bits in a port configuration.
 615  *
 616  * @param config Pointer to configuration structure.
 617  * @param stopbits Number of stop bits, or -1 to retain current setting.
 618  *
 619  * @return SP_OK upon success, a negative error code otherwise.
 620  *
 621  * @since 0.1.0
 622  */
 623 enum sp_return sp_set_config_stopbits(struct sp_port_config *config, int stopbits);
 624
 625 /**
 626  * Set the RTS pin behaviour for the specified serial port.
 627  *
 628  * @param port Pointer to port structure.
 629  * @param rts RTS pin mode.
 630  *
 631  * @return SP_OK upon success, a negative error code otherwise.
 632  *
 633  * @since 0.1.0
 634  */
 635 enum sp_return sp_set_rts(struct sp_port *port, enum sp_rts rts);
 636
 637 /**
 638  * Get the RTS pin behaviour from a port configuration.
 639  *
 640  * The user should allocate a variable of type enum sp_rts and pass a pointer to this
 641  * to receive the result.
 642  *
 643  * @param config Pointer to configuration structure.
 644  * @param rts_ptr Pointer to variable to store result.
 645  *
 646  * @return SP_OK upon success, a negative error code otherwise.
 647  *
 648  * @since 0.1.0
 649  */
 650 enum sp_return sp_get_config_rts(const struct sp_port_config *config, enum sp_rts *rts_ptr);
 651
 652 /**
 653  * Set the RTS pin behaviour in a port configuration.
 654  *
 655  * @param config Pointer to configuration structure.
 656  * @param rts RTS pin mode, or -1 to retain current setting.
 657  *
 658  * @return SP_OK upon success, a negative error code otherwise.
 659  *
 660  * @since 0.1.0
 661  */
 662 enum sp_return sp_set_config_rts(struct sp_port_config *config, enum sp_rts rts);
 663
 664 /**
 665  * Set the CTS pin behaviour for the specified serial port.
 666  *
 667  * @param port Pointer to port structure.
 668  * @param cts CTS pin mode.
 669  *
 670  * @return SP_OK upon success, a negative error code otherwise.
 671  *
 672  * @since 0.1.0
 673  */
 674 enum sp_return sp_set_cts(struct sp_port *port, enum sp_cts cts);
 675
 676 /**
 677  * Get the CTS pin behaviour from a port configuration.
 678  *
 679  * The user should allocate a variable of type enum sp_cts and pass a pointer to this
 680  * to receive the result.
 681  *
 682  * @param config Pointer to configuration structure.
 683  * @param cts_ptr Pointer to variable to store result.
 684  *
 685  * @return SP_OK upon success, a negative error code otherwise.
 686  *
 687  * @since 0.1.0
 688  */
 689 enum sp_return sp_get_config_cts(const struct sp_port_config *config, enum sp_cts *cts_ptr);
 690
 691 /**
 692  * Set the CTS pin behaviour in a port configuration.
 693  *
 694  * @param config Pointer to configuration structure.
 695  * @param cts CTS pin mode, or -1 to retain current setting.
 696  *
 697  * @return SP_OK upon success, a negative error code otherwise.
 698  *
 699  * @since 0.1.0
 700  */
 701 enum sp_return sp_set_config_cts(struct sp_port_config *config, enum sp_cts cts);
 702
 703 /**
 704  * Set the DTR pin behaviour for the specified serial port.
 705  *
 706  * @param port Pointer to port structure.
 707  * @param dtr DTR pin mode.
 708  *
 709  * @return SP_OK upon success, a negative error code otherwise.
 710  *
 711  * @since 0.1.0
 712  */
 713 enum sp_return sp_set_dtr(struct sp_port *port, enum sp_dtr dtr);
 714
 715 /**
 716  * Get the DTR pin behaviour from a port configuration.
 717  *
 718  * The user should allocate a variable of type enum sp_dtr and pass a pointer to this
 719  * to receive the result.
 720  *
 721  * @param config Pointer to configuration structure.
 722  * @param dtr_ptr Pointer to variable to store result.
 723  *
 724  * @return SP_OK upon success, a negative error code otherwise.
 725  *
 726  * @since 0.1.0
 727  */
 728 enum sp_return sp_get_config_dtr(const struct sp_port_config *config, enum sp_dtr *dtr_ptr);
 729
 730 /**
 731  * Set the DTR pin behaviour in a port configuration.
 732  *
 733  * @param config Pointer to configuration structure.
 734  * @param dtr DTR pin mode, or -1 to retain current setting.
 735  *
 736  * @return SP_OK upon success, a negative error code otherwise.
 737  *
 738  * @since 0.1.0
 739  */
 740 enum sp_return sp_set_config_dtr(struct sp_port_config *config, enum sp_dtr dtr);
 741
 742 /**
 743  * Set the DSR pin behaviour for the specified serial port.
 744  *
 745  * @param port Pointer to port structure.
 746  * @param dsr DSR pin mode.
 747  *
 748  * @return SP_OK upon success, a negative error code otherwise.
 749  *
 750  * @since 0.1.0
 751  */
 752 enum sp_return sp_set_dsr(struct sp_port *port, enum sp_dsr dsr);
 753
 754 /**
 755  * Get the DSR pin behaviour from a port configuration.
 756  *
 757  * The user should allocate a variable of type enum sp_dsr and pass a pointer to this
 758  * to receive the result.
 759  *
 760  * @param config Pointer to configuration structure.
 761  * @param dsr_ptr Pointer to variable to store result.
 762  *
 763  * @return SP_OK upon success, a negative error code otherwise.
 764  *
 765  * @since 0.1.0
 766  */
 767 enum sp_return sp_get_config_dsr(const struct sp_port_config *config, enum sp_dsr *dsr_ptr);
 768
 769 /**
 770  * Set the DSR pin behaviour in a port configuration.
 771  *
 772  * @param config Pointer to configuration structure.
 773  * @param dsr DSR pin mode, or -1 to retain current setting.
 774  *
 775  * @return SP_OK upon success, a negative error code otherwise.
 776  *
 777  * @since 0.1.0
 778  */
 779 enum sp_return sp_set_config_dsr(struct sp_port_config *config, enum sp_dsr dsr);
 780
 781 /**
 782  * Set the XON/XOFF configuration for the specified serial port.
 783  *
 784  * @param port Pointer to port structure.
 785  * @param xon_xoff XON/XOFF mode.
 786  *
 787  * @return SP_OK upon success, a negative error code otherwise.
 788  *
 789  * @since 0.1.0
 790  */
 791 enum sp_return sp_set_xon_xoff(struct sp_port *port, enum sp_xonxoff xon_xoff);
 792
 793 /**
 794  * Get the XON/XOFF configuration from a port configuration.
 795  *
 796  * The user should allocate a variable of type enum sp_xonxoff and pass a pointer to this
 797  * to receive the result.
 798  *
 799  * @param config Pointer to configuration structure.
 800  * @param xon_xoff_ptr Pointer to variable to store result.
 801  *
 802  * @return SP_OK upon success, a negative error code otherwise.
 803  *
 804  * @since 0.1.0
 805  */
 806 enum sp_return sp_get_config_xon_xoff(const struct sp_port_config *config, enum sp_xonxoff *xon_xoff_ptr);
 807
 808 /**
 809  * Set the XON/XOFF configuration in a port configuration.
 810  *
 811  * @param config Pointer to configuration structure.
 812  * @param xon_xoff XON/XOFF mode, or -1 to retain current setting.
 813  *
 814  * @return SP_OK upon success, a negative error code otherwise.
 815  *
 816  * @since 0.1.0
 817  */
 818 enum sp_return sp_set_config_xon_xoff(struct sp_port_config *config, enum sp_xonxoff xon_xoff);
 819
 820 /**
 821  * Set the flow control type in a port configuration.
 822  *
 823  * This function is a wrapper that sets the RTS, CTS, DTR, DSR and
 824  * XON/XOFF settings as necessary for the specified flow control
 825  * type. For more fine-grained control of these settings, use their
 826  * individual configuration functions.
 827  *
 828  * @param config Pointer to configuration structure.
 829  * @param flowcontrol Flow control setting to use.
 830  *
 831  * @return SP_OK upon success, a negative error code otherwise.
 832  *
 833  * @since 0.1.0
 834  */
 835 enum sp_return sp_set_config_flowcontrol(struct sp_port_config *config, enum sp_flowcontrol flowcontrol);
 836
 837 /**
 838  * Set the flow control type for the specified serial port.
 839  *
 840  * This function is a wrapper that sets the RTS, CTS, DTR, DSR and
 841  * XON/XOFF settings as necessary for the specified flow control
 842  * type. For more fine-grained control of these settings, use their
 843  * individual configuration functions.
 844  *
 845  * @param port Pointer to port structure.
 846  * @param flowcontrol Flow control setting to use.
 847  *
 848  * @return SP_OK upon success, a negative error code otherwise.
 849  *
 850  * @since 0.1.0
 851  */
 852 enum sp_return sp_set_flowcontrol(struct sp_port *port, enum sp_flowcontrol flowcontrol);
 853
 854 /**
 855  * @}
 856  * @defgroup Data Reading, writing, and flushing data
 857  * @{
 858 */
 859
 860 /**
 861  * Read bytes from the specified serial port, blocking until complete.
 862  *
 863  * @warning If your program runs on Unix, defines its own signal handlers, and
 864  *          needs to abort blocking reads when these are called, then you
 865  *          should not use this function. It repeats system calls that return
 866  *          with EINTR. To be able to abort a read from a signal handler, you
 867  *          should implement your own blocking read using sp_nonblocking_read()
 868  *          together with a blocking method that makes sense for your program.
 869  *          E.g. you can obtain the file descriptor for an open port using
 870  *          sp_get_port_handle() and use this to call select() or pselect(),
 871  *          with appropriate arrangements to return if a signal is received.
 872  *
 873  * @param port Pointer to port structure.
 874  * @param buf Buffer in which to store the bytes read.
 875  * @param count Requested number of bytes to read.
 876  * @param timeout Timeout in milliseconds, or zero to wait indefinitely.
 877  *
 878  * @return The number of bytes read on success, or a negative error code. If
 879  *         the number of bytes returned is less than that requested, the
 880  *         timeout was reached before the requested number of bytes was
 881  *         available. If timeout is zero, the function will always return
 882  *         either the requested number of bytes or a negative error code.
 883  *
 884  * @since 0.1.0
 885  */
 886 enum sp_return sp_blocking_read(struct sp_port *port, void *buf, size_t count, unsigned int timeout);
 887
 888 /**
 889  * Read bytes from the specified serial port, without blocking.
 890  *
 891  * @param port Pointer to port structure.
 892  * @param buf Buffer in which to store the bytes read.
 893  * @param count Maximum number of bytes to read.
 894  *
 895  * @return The number of bytes read on success, or a negative error code. The
 896  *         number of bytes returned may be any number from zero to the maximum
 897  *         that was requested.
 898  *
 899  * @since 0.1.0
 900  */
 901 enum sp_return sp_nonblocking_read(struct sp_port *port, void *buf, size_t count);
 902
 903 /**
 904  * Write bytes to the specified serial port, blocking until complete.
 905  *
 906  * Note that this function only ensures that the accepted bytes have been
 907  * written to the OS; they may be held in driver or hardware buffers and not
 908  * yet physically transmitted. To check whether all written bytes have actually
 909  * been transmitted, use the sp_output_waiting() function. To wait until all
 910  * written bytes have actually been transmitted, use the sp_drain() function.
 911  *
 912  * @warning If your program runs on Unix, defines its own signal handlers, and
 913  *          needs to abort blocking writes when these are called, then you
 914  *          should not use this function. It repeats system calls that return
 915  *          with EINTR. To be able to abort a write from a signal handler, you
 916  *          should implement your own blocking write using sp_nonblocking_write()
 917  *          together with a blocking method that makes sense for your program.
 918  *          E.g. you can obtain the file descriptor for an open port using
 919  *          sp_get_port_handle() and use this to call select() or pselect(),
 920  *          with appropriate arrangements to return if a signal is received.
 921  *
 922  * @param port Pointer to port structure.
 923  * @param buf Buffer containing the bytes to write.
 924  * @param count Requested number of bytes to write.
 925  * @param timeout Timeout in milliseconds, or zero to wait indefinitely.
 926  *
 927  * @return The number of bytes written on success, or a negative error code.
 928  *         If the number of bytes returned is less than that requested, the
 929  *         timeout was reached before the requested number of bytes was
 930  *         written. If timeout is zero, the function will always return
 931  *         either the requested number of bytes or a negative error code. In
 932  *         the event of an error there is no way to determine how many bytes
 933  *         were sent before the error occured.
 934  *
 935  * @since 0.1.0
 936  */
 937 enum sp_return sp_blocking_write(struct sp_port *port, const void *buf, size_t count, unsigned int timeout);
 938
 939 /**
 940  * Write bytes to the specified serial port, without blocking.
 941  *
 942  * Note that this function only ensures that the accepted bytes have been
 943  * written to the OS; they may be held in driver or hardware buffers and not
 944  * yet physically transmitted. To check whether all written bytes have actually
 945  * been transmitted, use the sp_output_waiting() function. To wait until all
 946  * written bytes have actually been transmitted, use the sp_drain() function.
 947  *
 948  * @param port Pointer to port structure.
 949  * @param buf Buffer containing the bytes to write.
 950  * @param count Maximum number of bytes to write.
 951  *
 952  * @return The number of bytes written on success, or a negative error code.
 953  *         The number of bytes returned may be any number from zero to the
 954  *         maximum that was requested.
 955  *
 956  * @since 0.1.0
 957  */
 958 enum sp_return sp_nonblocking_write(struct sp_port *port, const void *buf, size_t count);
 959
 960 /**
 961  * Gets the number of bytes waiting in the input buffer.
 962  *
 963  * @param port Pointer to port structure.
 964  *
 965  * @return Number of bytes waiting on success, a negative error code otherwise.
 966  *
 967  * @since 0.1.0
 968  */
 969 enum sp_return sp_input_waiting(struct sp_port *port);
 970
 971 /**
 972  * Gets the number of bytes waiting in the output buffer.
 973  *
 974  * @param port Pointer to port structure.
 975  *
 976  * @return Number of bytes waiting on success, a negative error code otherwise.
 977  *
 978  * @since 0.1.0
 979  */
 980 enum sp_return sp_output_waiting(struct sp_port *port);
 981
 982 /**
 983  * Flush serial port buffers. Data in the selected buffer(s) is discarded.
 984  *
 985  * @param port Pointer to port structure.
 986  * @param buffers Which buffer(s) to flush.
 987  *
 988  * @return SP_OK upon success, a negative error code otherwise.
 989  *
 990  * @since 0.1.0
 991  */
 992 enum sp_return sp_flush(struct sp_port *port, enum sp_buffer buffers);
 993
 994 /**
 995  * Wait for buffered data to be transmitted.
 996  *
 997  * @warning If your program runs on Unix, defines its own signal handlers, and
 998  *          needs to abort draining the output buffer when when these are
 999  *          called, then you should not use this function. It repeats system
1000  *          calls that return with EINTR. To be able to abort a drain from a
1001  *          signal handler, you would need to implement your own blocking
1002  *          drain by polling the result of sp_output_waiting().
1003  *
1004  * @param port Pointer to port structure.
1005  *
1006  * @return SP_OK upon success, a negative error code otherwise.
1007  *
1008  * @since 0.1.0
1009  */
1010 enum sp_return sp_drain(struct sp_port *port);
1011
1012 /**
1013  * @}
1014  * @defgroup Waiting Waiting for events
1015  * @{
1016  */
1017
1018 /**
1019  * Allocate storage for a set of events.
1020  *
1021  * The user should allocate a variable of type struct sp_event_set *,
1022  * then pass a pointer to this variable to receive the result.
1023  *
1024  * The result should be freed after use by calling sp_free_event_set().
1025  *
1026  * @return SP_OK upon success, a negative error code otherwise.
1027  *
1028  * @since 0.1.0
1029  */
1030 enum sp_return sp_new_event_set(struct sp_event_set **result_ptr);
1031
1032 /**
1033  * Add events to a struct sp_event_set for a given port.
1034  *
1035  * The port must first be opened by calling sp_open() using the same port
1036  * structure.
1037  *
1038  * After the port is closed or the port structure freed, the results may
1039  * no longer be valid.
1040  *
1041  * @param event_set Event set to update.
1042  * @param port Pointer to port structure.
1043  * @param mask Bitmask of events to be waited for.
1044  *
1045  * @return SP_OK upon success, a negative error code otherwise.
1046  *
1047  * @since 0.1.0
1048  */
1049 enum sp_return sp_add_port_events(struct sp_event_set *event_set,
1050         const struct sp_port *port, enum sp_event mask);
1051
1052 /**
1053  * Wait for any of a set of events to occur.
1054  *
1055  * @param event_set Event set to wait on.
1056  * @param timeout Timeout in milliseconds, or zero to wait indefinitely.
1057  *
1058  * @return SP_OK upon success, a negative error code otherwise.
1059  *
1060  * @since 0.1.0
1061  */
1062 enum sp_return sp_wait(struct sp_event_set *event_set, unsigned int timeout);
1063
1064 /**
1065  * Free a structure allocated by sp_new_event_set().
1066  *
1067  * @since 0.1.0
1068  */
1069 void sp_free_event_set(struct sp_event_set *event_set);
1070
1071 /**
1072  * @}
1073  * @defgroup Signals Port signalling operations
1074  * @{
1075  */
1076
1077 /**
1078  * Gets the status of the control signals for the specified port.
1079  *
1080  * The user should allocate a variable of type "enum sp_signal" and pass a
1081  * pointer to this variable to receive the result. The result is a bitmask
1082  * in which individual signals can be checked by bitwise OR with values of
1083  * the sp_signal enum.
1084  *
1085  * @param port Pointer to port structure.
1086  * @param signals Pointer to variable to receive result.
1087  *
1088  * @return SP_OK upon success, a negative error code otherwise.
1089  *
1090  * @since 0.1.0
1091  */
1092 enum sp_return sp_get_signals(struct sp_port *port, enum sp_signal *signals);
1093
1094 /**
1095  * Put the port transmit line into the break state.
1096  *
1097  * @param port Pointer to port structure.
1098  *
1099  * @return SP_OK upon success, a negative error code otherwise.
1100  *
1101  * @since 0.1.0
1102  */
1103 enum sp_return sp_start_break(struct sp_port *port);
1104
1105 /**
1106  * Take the port transmit line out of the break state.
1107  *
1108  * @param port Pointer to port structure.
1109  *
1110  * @return SP_OK upon success, a negative error code otherwise.
1111  *
1112  * @since 0.1.0
1113  */
1114 enum sp_return sp_end_break(struct sp_port *port);
1115
1116 /**
1117  * @}
1118  * @defgroup Errors Obtaining error information
1119  * @{
1120 */
1121
1122 /**
1123  * Get the error code for a failed operation.
1124  *
1125  * In order to obtain the correct result, this function should be called
1126  * straight after the failure, before executing any other system operations.
1127  *
1128  * @return The system's numeric code for the error that caused the last
1129  *         operation to fail.
1130  *
1131  * @since 0.1.0
1132  */
1133 int sp_last_error_code(void);
1134
1135 /**
1136  * Get the error message for a failed operation.
1137  *
1138  * In order to obtain the correct result, this function should be called
1139  * straight after the failure, before executing other system operations.
1140  *
1141  * @return The system's message for the error that caused the last
1142  *         operation to fail. This string may be allocated by the function,
1143  *         and should be freed after use by calling sp_free_error_message().
1144  *
1145  * @since 0.1.0
1146  */
1147 char *sp_last_error_message(void);
1148
1149 /**
1150  * Free an error message returned by sp_last_error_message().
1151  *
1152  * @since 0.1.0
1153  */
1154 void sp_free_error_message(char *message);
1155
1156 /**
1157  * Set the handler function for library debugging messages.
1158  *
1159  * Debugging messages are generated by the library during each operation,
1160  * to help in diagnosing problems. The handler will be called for each
1161  * message. The handler can be set to NULL to ignore all debug messages.
1162  *
1163  * The handler function should accept a format string and variable length
1164  * argument list, in the same manner as e.g. printf().
1165  *
1166  * The default handler is sp_default_debug_handler().
1167  *
1168  * @since 0.1.0
1169  */
1170 void sp_set_debug_handler(void (*handler)(const char *format, ...));
1171
1172 /**
1173  * Default handler function for library debugging messages.
1174  *
1175  * This function prints debug messages to the standard error stream if the
1176  * environment variable LIBSERIALPORT_DEBUG is set. Otherwise, they are
1177  * ignored.
1178  *
1179  * @since 0.1.0
1180  */
1181 void sp_default_debug_handler(const char *format, ...);
1182
1183 /** @} */
1184
1185 /**
1186  * @defgroup Versions Version number querying functions, definitions, and macros
1187  *
1188  * This set of API calls returns two different version numbers related
1189  * to libserialport. The "package version" is the release version number of the
1190  * libserialport tarball in the usual "major.minor.micro" format, e.g. "0.1.0".
1191  *
1192  * The "library version" is independent of that; it is the libtool version
1193  * number in the "current:revision:age" format, e.g. "2:0:0".
1194  * See http://www.gnu.org/software/libtool/manual/libtool.html#Libtool-versioning for details.
1195  *
1196  * Both version numbers (and/or individual components of them) can be
1197  * retrieved via the API calls at runtime, and/or they can be checked at
1198  * compile/preprocessor time using the respective macros.
1199  *
1200  * @{
1201  */
1202
1203 /*
1204  * Package version macros (can be used for conditional compilation).
1205  */
1206
1207 /** The libserialport package 'major' version number. */
1208 #define SP_PACKAGE_VERSION_MAJOR @SP_PACKAGE_VERSION_MAJOR@
1209
1210 /** The libserialport package 'minor' version number. */
1211 #define SP_PACKAGE_VERSION_MINOR @SP_PACKAGE_VERSION_MINOR@
1212
1213 /** The libserialport package 'micro' version number. */
1214 #define SP_PACKAGE_VERSION_MICRO @SP_PACKAGE_VERSION_MICRO@
1215
1216 /** The libserialport package version ("major.minor.micro") as string. */
1217 #define SP_PACKAGE_VERSION_STRING "@SP_PACKAGE_VERSION@"
1218
1219 /*
1220  * Library/libtool version macros (can be used for conditional compilation).
1221  */
1222
1223 /** The libserialport libtool 'current' version number. */
1224 #define SP_LIB_VERSION_CURRENT @SP_LIB_VERSION_CURRENT@
1225
1226 /** The libserialport libtool 'revision' version number. */
1227 #define SP_LIB_VERSION_REVISION @SP_LIB_VERSION_REVISION@
1228
1229 /** The libserialport libtool 'age' version number. */
1230 #define SP_LIB_VERSION_AGE @SP_LIB_VERSION_AGE@
1231
1232 /** The libserialport libtool version ("current:revision:age") as string. */
1233 #define SP_LIB_VERSION_STRING "@SP_LIB_VERSION@"
1234
1235 /**
1236  * Get the major libserialport package version number.
1237  *
1238  * @return The major package version number.
1239  *
1240  * @since 0.1.0
1241  */
1242 int sp_get_major_package_version(void);
1243
1244 /**
1245  * Get the minor libserialport package version number.
1246  *
1247  * @return The minor package version number.
1248  *
1249  * @since 0.1.0
1250  */
1251 int sp_get_minor_package_version(void);
1252
1253 /**
1254  * Get the micro libserialport package version number.
1255  *
1256  * @return The micro package version number.
1257  *
1258  * @since 0.1.0
1259  */
1260 int sp_get_micro_package_version(void);
1261
1262 /**
1263  * Get the libserialport package version number as a string.
1264  *
1265  * @return The package version number string. The returned string is
1266  *         static and thus should NOT be free'd by the caller.
1267  *
1268  * @since 0.1.0
1269  */
1270 const char *sp_get_package_version_string(void);
1271
1272 /**
1273  * Get the "current" part of the libserialport library version number.
1274  *
1275  * @return The "current" library version number.
1276  *
1277  * @since 0.1.0
1278  */
1279 int sp_get_current_lib_version(void);
1280
1281 /**
1282  * Get the "revision" part of the libserialport library version number.
1283  *
1284  * @return The "revision" library version number.
1285  *
1286  * @since 0.1.0
1287  */
1288 int sp_get_revision_lib_version(void);
1289
1290 /**
1291  * Get the "age" part of the libserialport library version number.
1292  *
1293  * @return The "age" library version number.
1294  *
1295  * @since 0.1.0
1296  */
1297 int sp_get_age_lib_version(void);
1298
1299 /**
1300  * Get the libserialport library version number as a string.
1301  *
1302  * @return The library version number string. The returned string is
1303  *         static and thus should NOT be free'd by the caller.
1304  *
1305  * @since 0.1.0
1306  */
1307 const char *sp_get_lib_version_string(void);
1308
1309 /** @} */
1310
1311 #ifdef __cplusplus
1312 }
1313 #endif
1314
1315 #endif