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mirror of git://sigrok.org/libserialport synced 2023-08-10 21:13:24 +03:00
libserialport/libserialport.h.in
2013-11-27 14:35:36 +00:00

997 lines
33 KiB
C

/*
* This file is part of the libserialport project.
*
* Copyright (C) 2013 Martin Ling <martin-libserialport@earth.li>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* @mainpage libserialport API
*
* Introduction
* ============
*
* libserialport is a minimal library written in C that is intended to take
* care of the OS-specific details when writing software that uses serial ports.
*
* By writing your serial code to use libserialport, you enable it to work
* transparently on any platform supported by the library.
*
* The operations that are supported are:
*
* - @ref Enumeration (obtaining a list of serial ports on the system)
* - @ref Ports
* - @ref Configuration (baud rate, parity, etc.)
* - @ref Signals (modem control lines, breaks, etc.)
* - @ref Data
* - @ref Errors
*
* libserialport is an open source project released under the LGPL3+ license.
*
* API principles
* ==============
*
* The API is simple, and designed to be a minimal wrapper around the serial
* port support in each OS.
*
* Most functions take a pointer to a struct sp_port, which represents a serial
* port. These structures are always allocated and freed by the library, using
* the functions in the @ref Enumeration "Enumeration" section.
*
* Most functions have return type @ref sp_return and can return only four
* possible error values:
*
* - @ref SP_ERR_ARG means that a function was called with invalid
* arguments. This implies a bug in the caller. The arguments passed would
* be invalid regardless of the underlying OS or serial device involved.
*
* - @ref SP_ERR_FAIL means that the OS reported a failure. The error code or
* message provided by the OS can be obtained by calling sp_last_error_code()
* or sp_last_error_message().
*
* - @ref SP_ERR_SUPP indicates that there is no support for the requested
* operation in the current OS, driver or device. No error message is
* available from the OS in this case. There is either no way to request
* the operation in the first place, or libserialport does not know how to
* do so in the current version.
*
* - @ref SP_ERR_MEM indicates that a memory allocation failed.
*
* All of these error values are negative.
*
* Calls that succeed return @ref SP_OK, which is equal to zero. Some functions
* declared @ref sp_return can also return a positive value for a successful
* numeric result, e.g. sp_read() and sp_write().
*/
#ifndef LIBSERIALPORT_LIBSERIALPORT_H
#define LIBSERIALPORT_LIBSERIALPORT_H
#ifdef __cplusplus
extern "C" {
#endif
#include <stddef.h>
#ifdef _WIN32
#include <windows.h>
#endif
/* Package version macros (e.g. for conditional compilation). */
#define SP_PACKAGE_VERSION_MAJOR @SP_PACKAGE_VERSION_MAJOR@
#define SP_PACKAGE_VERSION_MINOR @SP_PACKAGE_VERSION_MINOR@
#define SP_PACKAGE_VERSION_MICRO @SP_PACKAGE_VERSION_MICRO@
#define SP_PACKAGE_VERSION_STRING "@SP_PACKAGE_VERSION@"
/* Library/libtool version macros (e.g. for conditional compilation). */
#define SP_LIB_VERSION_CURRENT @SP_LIB_VERSION_CURRENT@
#define SP_LIB_VERSION_REVISION @SP_LIB_VERSION_REVISION@
#define SP_LIB_VERSION_AGE @SP_LIB_VERSION_AGE@
#define SP_LIB_VERSION_STRING "@SP_LIB_VERSION@"
/** Return values. */
enum sp_return {
/** Operation completed successfully. */
SP_OK = 0,
/** Invalid arguments were passed to the function. */
SP_ERR_ARG = -1,
/** A system error occured while executing the operation. */
SP_ERR_FAIL = -2,
/** A memory allocation failed while executing the operation. */
SP_ERR_MEM = -3,
/** The requested operation is not supported by this system or device. */
SP_ERR_SUPP = -4,
};
/** Port access modes. */
enum sp_mode {
/** Open port for read access. */
SP_MODE_READ = 1,
/** Open port for write access. */
SP_MODE_WRITE = 2,
};
/** Buffer selection. */
enum sp_buffer {
/** Input buffer. */
SP_BUF_INPUT = 1,
/** Output buffer. */
SP_BUF_OUTPUT = 2,
/** Both buffers. */
SP_BUF_BOTH = 3,
};
/** Parity settings. */
enum sp_parity {
/** Special value to indicate setting should be left alone. */
SP_PARITY_INVALID = -1,
/** No parity. */
SP_PARITY_NONE = 0,
/** Odd parity. */
SP_PARITY_ODD = 1,
/** Even parity. */
SP_PARITY_EVEN = 2,
/** Mark parity. */
SP_PARITY_MARK = 3,
/** Space parity. */
SP_PARITY_SPACE = 4,
};
/** RTS pin behaviour. */
enum sp_rts {
/** Special value to indicate setting should be left alone. */
SP_RTS_INVALID = -1,
/** RTS off. */
SP_RTS_OFF = 0,
/** RTS on. */
SP_RTS_ON = 1,
/** RTS used for flow control. */
SP_RTS_FLOW_CONTROL = 2,
};
/** CTS pin behaviour. */
enum sp_cts {
/** Special value to indicate setting should be left alone. */
SP_CTS_INVALID = -1,
/** CTS ignored. */
SP_CTS_IGNORE = 0,
/** CTS used for flow control. */
SP_CTS_FLOW_CONTROL = 1,
};
/** DTR pin behaviour. */
enum sp_dtr {
/** Special value to indicate setting should be left alone. */
SP_DTR_INVALID = -1,
/** DTR off. */
SP_DTR_OFF = 0,
/** DTR on. */
SP_DTR_ON = 1,
/** DTR used for flow control. */
SP_DTR_FLOW_CONTROL = 2,
};
/** DSR pin behaviour. */
enum sp_dsr {
/** Special value to indicate setting should be left alone. */
SP_DSR_INVALID = -1,
/** DSR ignored. */
SP_DSR_IGNORE = 0,
/** DSR used for flow control. */
SP_DSR_FLOW_CONTROL = 1,
};
/** XON/XOFF flow control behaviour. */
enum sp_xonxoff {
/** Special value to indicate setting should be left alone. */
SP_XONXOFF_INVALID = -1,
/** XON/XOFF disabled. */
SP_XONXOFF_DISABLED = 0,
/** XON/XOFF enabled for input only. */
SP_XONXOFF_IN = 1,
/** XON/XOFF enabled for output only. */
SP_XONXOFF_OUT = 2,
/** XON/XOFF enabled for input and output. */
SP_XONXOFF_INOUT = 3,
};
/** Standard flow control combinations. */
enum sp_flowcontrol {
/** No flow control. */
SP_FLOWCONTROL_NONE = 0,
/** Software flow control using XON/XOFF characters. */
SP_FLOWCONTROL_XONXOFF = 1,
/** Hardware flow control using RTS/CTS signals. */
SP_FLOWCONTROL_RTSCTS = 2,
/** Hardware flow control using DTR/DSR signals. */
SP_FLOWCONTROL_DTRDSR = 3,
};
/** Input signals. */
enum sp_signal {
/** Clear to send. */
SP_SIG_CTS = 1,
/** Data set ready. */
SP_SIG_DSR = 2,
/** Data carrier detect. */
SP_SIG_DCD = 4,
/** Ring indicator. */
SP_SIG_RI = 8,
};
/** A serial port. */
struct sp_port;
/** Configuration for a serial port. */
struct sp_port_config;
/**
@defgroup Enumeration Port enumeration
@{
*/
/**
* Obtain a pointer to a new sp_port structure representing the named port.
*
* The user should allocate a variable of type "struct sp_port *" and pass a
* pointer to this to receive the result.
*
* The result should be freed after use by calling sp_free_port().
*
* If any error is returned, the variable pointed to by port_ptr will be set
* to NULL. Otherwise, it will be set to point to the newly allocated port.
*
* @return SP_OK upon success, a negative error code otherwise.
*/
enum sp_return sp_get_port_by_name(const char *portname, struct sp_port **port_ptr);
/**
* Free a port structure obtained from sp_get_port_by_name() or sp_copy_port().
*/
void sp_free_port(struct sp_port *port);
/**
* List the serial ports available on the system.
*
* The result obtained is an array of pointers to sp_port structures,
* terminated by a NULL. The user should allocate a variable of type
* "struct sp_port **" and pass a pointer to this to receive the result.
*
* The result should be freed after use by calling sp_free_port_list().
* If a port from the list is to be used after freeing the list, it must be
* copied first using sp_copy_port().
*
* If any error is returned, the variable pointed to by list_ptr will be set
* to NULL. Otherwise, it will be set to point to the newly allocated array.
*
* @return SP_OK upon success, a negative error code otherwise.
*/
enum sp_return sp_list_ports(struct sp_port ***list_ptr);
/**
* Make a new copy of a sp_port structure.
*
* The user should allocate a variable of type "struct sp_port *" and pass a
* pointer to this to receive the result.
*
* The copy should be freed after use by calling sp_free_port().
*
* If any error is returned, the variable pointed to by copy_ptr will be set
* to NULL. Otherwise, it will be set to point to the newly allocated copy.
*
* @return SP_OK upon success, a negative error code otherwise.
*/
enum sp_return sp_copy_port(const struct sp_port *port, struct sp_port **copy_ptr);
/**
* Free a port list obtained from sp_list_ports().
*
* This will also free all the sp_port structures referred to from the list;
* any that are to be retained must be copied first using sp_copy_port().
*/
void sp_free_port_list(struct sp_port **ports);
/**
* @}
* @defgroup Ports Opening, closing and querying ports
* @{
*/
/**
* Open the specified serial port.
*
* @param port Pointer to port structure.
* @param flags Flags to use when opening the serial port.
*
* @return SP_OK upon success, a negative error code otherwise.
*/
enum sp_return sp_open(struct sp_port *port, enum sp_mode flags);
/**
* Close the specified serial port.
*
* @return SP_OK upon success, a negative error code otherwise.
*/
enum sp_return sp_close(struct sp_port *port);
/**
* Get the name of a port.
*
* The name returned is whatever is normally used to refer to a port on the
* current operating system; e.g. for Windows it will usually be a "COMn"
* device name, and for Unix it will be a device path beginning with "/dev/".
*
* @param port Pointer to port structure.
*
* @return The port name, or NULL if an invalid port is passed. The name
* string is part of the port structure and may not be used after the
* port structure has been freed.
*/
char *sp_get_port_name(const struct sp_port *port);
/**
* Get the operating system handle for a port.
*
* The type of the handle depends on the operating system. On Unix based
* systems, the handle is a file descriptor of type "int". On Windows, the
* handle is of type "HANDLE". The user should allocate a variable of the
* appropriate type and pass a pointer to this to receive the result.
*
* To obtain a valid handle, the port must first be opened by calling
* sp_open() using the same port structure.
*
* After the port is closed or the port structure freed, the handle may
* no longer be valid.
*
* @warning This feature is provided so that programs may make use of
* OS-specific functionality where desired. Doing so obviously
* comes at a cost in portability. It also cannot be guaranteed
* that direct usage of the OS handle will not conflict with the
* library's own usage of the port. Be careful.
*
* @return SP_OK upon success, a negative error code otherwise.
*/
enum sp_return sp_get_port_handle(const struct sp_port *port, void *result_ptr);
/**
* @}
* @defgroup Configuration Setting port parameters
* @{
*/
/**
* Allocate a port configuration structure.
*
* The user should allocate a variable of type "struct sp_config *" and pass a
* pointer to this to receive the result. The variable will be updated to
* point to the new configuration structure. The structure is opaque and must
* be accessed via the functions provided.
*
* All parameters in the structure will be initialised to special values which
* are ignored by sp_set_config().
*
* The structure should be freed after use by calling sp_free_config().
*
* @param config_ptr Pointer to variable to receive result.
*
* @return SP_OK upon success, a negative error code otherwise.
*/
enum sp_return sp_new_config(struct sp_port_config **config_ptr);
/**
* Free a port configuration structure.
*
* @param config Pointer to configuration structure.
*/
void sp_free_config(struct sp_port_config *config);
/**
* Get the current configuration of the specified serial port.
*
* The user should allocate a configuration structure using sp_new_config()
* and pass this as the config parameter. The configuration structure will
* be updated with the port configuration.
*
* Any parameters that are configured with settings not recognised or
* supported by libserialport, will be set to special values that are
* ignored by sp_set_config().
*
* @return SP_OK upon success, a negative error code otherwise.
*/
enum sp_return sp_get_config(struct sp_port *port, struct sp_port_config *config);
/**
* Set the configuration for the specified serial port.
*
* For each parameter in the configuration, there is a special value (usually
* -1, but see the documentation for each field). These values will be ignored
* and the corresponding setting left unchanged on the port.
*
* @return SP_OK upon success, a negative error code otherwise.
*/
enum sp_return sp_set_config(struct sp_port *port, const struct sp_port_config *config);
/**
* Set the baud rate for the specified serial port.
*
* @param port Pointer to port structure.
* @param baudrate Baud rate in bits per second.
*
* @return SP_OK upon success, a negative error code otherwise.
*/
enum sp_return sp_set_baudrate(struct sp_port *port, int baudrate);
/**
* Get the baud rate from a port configuration.
*
* The user should allocate a variable of type int and pass a pointer to this
* to receive the result.
*
* @param config Pointer to configuration structure.
* @param baudrate_ptr Pointer to variable to store result.
*
* @return SP_OK upon success, a negative error code otherwise.
*/
enum sp_return sp_get_config_baudrate(const struct sp_port_config *config, int *baudrate_ptr);
/**
* Set the baud rate in a port configuration.
*
* @param config Pointer to configuration structure.
* @param baudrate Baud rate in bits per second, or -1 to retain current setting.
*
* @return SP_OK upon success, a negative error code otherwise.
*/
enum sp_return sp_set_config_baudrate(struct sp_port_config *config, int baudrate);
/**
* Set the data bits for the specified serial port.
*
* @param port Pointer to port structure.
* @param bits Number of data bits.
*
* @return SP_OK upon success, a negative error code otherwise.
*/
enum sp_return sp_set_bits(struct sp_port *port, int bits);
/**
* Get the data bits from a port configuration.
*
* The user should allocate a variable of type int and pass a pointer to this
* to receive the result.
*
* @param config Pointer to configuration structure.
* @param bits_ptr Pointer to variable to store result.
*
* @return SP_OK upon success, a negative error code otherwise.
*/
enum sp_return sp_get_config_bits(const struct sp_port_config *config, int *bits_ptr);
/**
* Set the data bits in a port configuration.
*
* @param config Pointer to configuration structure.
* @param bits Number of data bits, or -1 to retain current setting.
*
* @return SP_OK upon success, a negative error code otherwise.
*/
enum sp_return sp_set_config_bits(struct sp_port_config *config, int bits);
/**
* Set the parity setting for the specified serial port.
*
* @param port Pointer to port structure.
* @param parity Parity setting.
*
* @return SP_OK upon success, a negative error code otherwise.
*/
enum sp_return sp_set_parity(struct sp_port *port, enum sp_parity parity);
/**
* Get the parity setting from a port configuration.
*
* The user should allocate a variable of type enum sp_parity and pass a pointer to this
* to receive the result.
*
* @param config Pointer to configuration structure.
* @param parity_ptr Pointer to variable to store result.
*
* @return SP_OK upon success, a negative error code otherwise.
*/
enum sp_return sp_get_config_parity(const struct sp_port_config *config, enum sp_parity *parity_ptr);
/**
* Set the parity setting in a port configuration.
*
* @param config Pointer to configuration structure.
* @param parity Parity setting, or -1 to retain current setting.
*
* @return SP_OK upon success, a negative error code otherwise.
*/
enum sp_return sp_set_config_parity(struct sp_port_config *config, enum sp_parity parity);
/**
* Set the stop bits for the specified serial port.
*
* @param port Pointer to port structure.
* @param stopbits Number of stop bits.
*
* @return SP_OK upon success, a negative error code otherwise.
*/
enum sp_return sp_set_stopbits(struct sp_port *port, int stopbits);
/**
* Get the stop bits from a port configuration.
*
* The user should allocate a variable of type int and pass a pointer to this
* to receive the result.
*
* @param config Pointer to configuration structure.
* @param stopbits_ptr Pointer to variable to store result.
*
* @return SP_OK upon success, a negative error code otherwise.
*/
enum sp_return sp_get_config_stopbits(const struct sp_port_config *config, int *stopbits_ptr);
/**
* Set the stop bits in a port configuration.
*
* @param config Pointer to configuration structure.
* @param stopbits Number of stop bits, or -1 to retain current setting.
*
* @return SP_OK upon success, a negative error code otherwise.
*/
enum sp_return sp_set_config_stopbits(struct sp_port_config *config, int stopbits);
/**
* Set the RTS pin behaviour for the specified serial port.
*
* @param port Pointer to port structure.
* @param rts RTS pin mode.
*
* @return SP_OK upon success, a negative error code otherwise.
*/
enum sp_return sp_set_rts(struct sp_port *port, enum sp_rts rts);
/**
* Get the RTS pin behaviour from a port configuration.
*
* The user should allocate a variable of type enum sp_rts and pass a pointer to this
* to receive the result.
*
* @param config Pointer to configuration structure.
* @param rts_ptr Pointer to variable to store result.
*
* @return SP_OK upon success, a negative error code otherwise.
*/
enum sp_return sp_get_config_rts(const struct sp_port_config *config, enum sp_rts *rts_ptr);
/**
* Set the RTS pin behaviour in a port configuration.
*
* @param config Pointer to configuration structure.
* @param rts RTS pin mode, or -1 to retain current setting.
*
* @return SP_OK upon success, a negative error code otherwise.
*/
enum sp_return sp_set_config_rts(struct sp_port_config *config, enum sp_rts rts);
/**
* Set the CTS pin behaviour for the specified serial port.
*
* @param port Pointer to port structure.
* @param cts CTS pin mode.
*
* @return SP_OK upon success, a negative error code otherwise.
*/
enum sp_return sp_set_cts(struct sp_port *port, enum sp_cts cts);
/**
* Get the CTS pin behaviour from a port configuration.
*
* The user should allocate a variable of type enum sp_cts and pass a pointer to this
* to receive the result.
*
* @param config Pointer to configuration structure.
* @param cts_ptr Pointer to variable to store result.
*
* @return SP_OK upon success, a negative error code otherwise.
*/
enum sp_return sp_get_config_cts(const struct sp_port_config *config, enum sp_cts *cts_ptr);
/**
* Set the CTS pin behaviour in a port configuration.
*
* @param config Pointer to configuration structure.
* @param cts CTS pin mode, or -1 to retain current setting.
*
* @return SP_OK upon success, a negative error code otherwise.
*/
enum sp_return sp_set_config_cts(struct sp_port_config *config, enum sp_cts cts);
/**
* Set the DTR pin behaviour for the specified serial port.
*
* @param port Pointer to port structure.
* @param dtr DTR pin mode.
*
* @return SP_OK upon success, a negative error code otherwise.
*/
enum sp_return sp_set_dtr(struct sp_port *port, enum sp_dtr dtr);
/**
* Get the DTR pin behaviour from a port configuration.
*
* The user should allocate a variable of type enum sp_dtr and pass a pointer to this
* to receive the result.
*
* @param config Pointer to configuration structure.
* @param dtr_ptr Pointer to variable to store result.
*
* @return SP_OK upon success, a negative error code otherwise.
*/
enum sp_return sp_get_config_dtr(const struct sp_port_config *config, enum sp_dtr *dtr_ptr);
/**
* Set the DTR pin behaviour in a port configuration.
*
* @param config Pointer to configuration structure.
* @param dtr DTR pin mode, or -1 to retain current setting.
*
* @return SP_OK upon success, a negative error code otherwise.
*/
enum sp_return sp_set_config_dtr(struct sp_port_config *config, enum sp_dtr dtr);
/**
* Set the DSR pin behaviour for the specified serial port.
*
* @param port Pointer to port structure.
* @param dsr DSR pin mode.
*
* @return SP_OK upon success, a negative error code otherwise.
*/
enum sp_return sp_set_dsr(struct sp_port *port, enum sp_dsr dsr);
/**
* Get the DSR pin behaviour from a port configuration.
*
* The user should allocate a variable of type enum sp_dsr and pass a pointer to this
* to receive the result.
*
* @param config Pointer to configuration structure.
* @param dsr_ptr Pointer to variable to store result.
*
* @return SP_OK upon success, a negative error code otherwise.
*/
enum sp_return sp_get_config_dsr(const struct sp_port_config *config, enum sp_dsr *dsr_ptr);
/**
* Set the DSR pin behaviour in a port configuration.
*
* @param config Pointer to configuration structure.
* @param dsr DSR pin mode, or -1 to retain current setting.
*
* @return SP_OK upon success, a negative error code otherwise.
*/
enum sp_return sp_set_config_dsr(struct sp_port_config *config, enum sp_dsr dsr);
/**
* Set the XON/XOFF configuration for the specified serial port.
*
* @param port Pointer to port structure.
* @param xon_xoff XON/XOFF mode.
*
* @return SP_OK upon success, a negative error code otherwise.
*/
enum sp_return sp_set_xon_xoff(struct sp_port *port, enum sp_xonxoff xon_xoff);
/**
* Get the XON/XOFF configuration from a port configuration.
*
* The user should allocate a variable of type enum sp_xonxoff and pass a pointer to this
* to receive the result.
*
* @param config Pointer to configuration structure.
* @param xon_xoff_ptr Pointer to variable to store result.
*
* @return SP_OK upon success, a negative error code otherwise.
*/
enum sp_return sp_get_config_xon_xoff(const struct sp_port_config *config, enum sp_xonxoff *xon_xoff_ptr);
/**
* Set the XON/XOFF configuration in a port configuration.
*
* @param config Pointer to configuration structure.
* @param xon_xoff XON/XOFF mode, or -1 to retain current setting.
*
* @return SP_OK upon success, a negative error code otherwise.
*/
enum sp_return sp_set_config_xon_xoff(struct sp_port_config *config, enum sp_xonxoff xon_xoff);
/**
* Set the flow control type in a port configuration.
*
* This function is a wrapper that sets the RTS, CTS, DTR, DSR and
* XON/XOFF settings as necessary for the specified flow control
* type. For more fine-grained control of these settings, use their
* individual configuration functions.
*
* @param config Pointer to configuration structure.
* @param flowcontrol Flow control setting to use.
*
* @return SP_OK upon success, a negative error code otherwise.
*/
enum sp_return sp_set_config_flowcontrol(struct sp_port_config *config, enum sp_flowcontrol flowcontrol);
/**
* Set the flow control type for the specified serial port.
*
* This function is a wrapper that sets the RTS, CTS, DTR, DSR and
* XON/XOFF settings as necessary for the specified flow control
* type. For more fine-grained control of these settings, use their
* individual configuration functions.
*
* @param port Pointer to port structure.
* @param flowcontrol Flow control setting to use.
*
* @return SP_OK upon success, a negative error code otherwise.
*/
enum sp_return sp_set_flowcontrol(struct sp_port *port, enum sp_flowcontrol flowcontrol);
/**
* @}
* @defgroup Data Reading, writing, and flushing data
* @{
*/
/**
* Read bytes from the specified serial port, blocking until complete.
*
* @warning If your program runs on Unix, defines its own signal handlers, and
* needs to abort blocking reads when these are called, then you
* should not use this function. It repeats system calls that return
* with EINTR. To be able to abort a read from a signal handler, you
* should implement your own blocking read using sp_nonblocking_read()
* together with a blocking method that makes sense for your program.
* E.g. you can obtain the file descriptor for an open port using
* sp_get_port_handle() and use this to call select() or pselect(),
* with appropriate arrangements to return if a signal is received.
*
* @param port Pointer to port structure.
* @param buf Buffer in which to store the bytes read.
* @param count Requested number of bytes to read.
* @param timeout Timeout in milliseconds, or zero to wait indefinitely.
*
* @return The number of bytes read on success, or a negative error code. If
* the number of bytes returned is less than that requested, the
* timeout was reached before the requested number of bytes was
* available. If timeout is zero, the function will always return
* either the requested number of bytes or a negative error code.
*/
enum sp_return sp_blocking_read(struct sp_port *port, void *buf, size_t count, unsigned int timeout);
/**
* Read bytes from the specified serial port, without blocking.
*
* @param port Pointer to port structure.
* @param buf Buffer in which to store the bytes read.
* @param count Maximum number of bytes to read.
*
* @return The number of bytes read on success, or a negative error code. The
* number of bytes returned may be any number from zero to the maximum
* that was requested.
*/
enum sp_return sp_nonblocking_read(struct sp_port *port, void *buf, size_t count);
/**
* Write bytes to the specified serial port, blocking until complete.
*
* Note that this function only ensures that the accepted bytes have been
* written to the OS; they may be held in driver or hardware buffers and not
* yet physically transmitted. To check whether all written bytes have actually
* been transmitted, use the sp_output_waiting() function. To wait until all
* written bytes have actually been transmitted, use the sp_drain() function.
*
* @warning If your program runs on Unix, defines its own signal handlers, and
* needs to abort blocking writes when these are called, then you
* should not use this function. It repeats system calls that return
* with EINTR. To be able to abort a write from a signal handler, you
* should implement your own blocking write using sp_nonblocking_write()
* together with a blocking method that makes sense for your program.
* E.g. you can obtain the file descriptor for an open port using
* sp_get_port_handle() and use this to call select() or pselect(),
* with appropriate arrangements to return if a signal is received.
*
* @param port Pointer to port structure.
* @param buf Buffer containing the bytes to write.
* @param count Requested number of bytes to write.
* @param timeout Timeout in milliseconds, or zero to wait indefinitely.
*
* @return The number of bytes written on success, or a negative error code.
* If the number of bytes returned is less than that requested, the
* timeout was reached before the requested number of bytes was
* written. If timeout is zero, the function will always return
* either the requested number of bytes or a negative error code. In
* the event of an error there is no way to determine how many bytes
* were sent before the error occured.
*/
enum sp_return sp_blocking_write(struct sp_port *port, const void *buf, size_t count, unsigned int timeout);
/**
* Write bytes to the specified serial port, without blocking.
*
* Note that this function only ensures that the accepted bytes have been
* written to the OS; they may be held in driver or hardware buffers and not
* yet physically transmitted. To check whether all written bytes have actually
* been transmitted, use the sp_output_waiting() function. To wait until all
* written bytes have actually been transmitted, use the sp_drain() function.
*
* @param port Pointer to port structure.
* @param buf Buffer containing the bytes to write.
* @param count Maximum number of bytes to write.
*
* @return The number of bytes written on success, or a negative error code.
* The number of bytes returned may be any number from zero to the
* maximum that was requested.
*/
enum sp_return sp_nonblocking_write(struct sp_port *port, const void *buf, size_t count);
/**
* Gets the number of bytes waiting in the input buffer.
*
* @param port Pointer to port structure.
*
* @return Number of bytes waiting on success, a negative error code otherwise.
*/
enum sp_return sp_input_waiting(struct sp_port *port);
/**
* Gets the number of bytes waiting in the output buffer.
*
* @param port Pointer to port structure.
*
* @return Number of bytes waiting on success, a negative error code otherwise.
*/
enum sp_return sp_output_waiting(struct sp_port *port);
/**
* Flush serial port buffers. Data in the selected buffer(s) is discarded.
*
* @param port Pointer to port structure.
* @param buffers Which buffer(s) to flush.
*
* @return SP_OK upon success, a negative error code otherwise.
*/
enum sp_return sp_flush(struct sp_port *port, enum sp_buffer buffers);
/**
* Wait for buffered data to be transmitted.
*
* @warning If your program runs on Unix, defines its own signal handlers, and
* needs to abort draining the output buffer when when these are
* called, then you should not use this function. It repeats system
* calls that return with EINTR. To be able to abort a drain from a
* signal handler, you would need to implement your own blocking
* drain by polling the result of sp_output_waiting().
*
* @param port Pointer to port structure.
*
* @return SP_OK upon success, a negative error code otherwise.
*/
enum sp_return sp_drain(struct sp_port *port);
/**
* @}
* @defgroup Signals Port signalling operations
* @{
*/
/**
* Gets the status of the control signals for the specified port.
*
* The user should allocate a variable of type "enum sp_signal" and pass a
* pointer to this variable to receive the result. The result is a bitmask
* in which individual signals can be checked by bitwise OR with values of
* the sp_signal enum.
*
* @param port Pointer to port structure.
* @param signals Pointer to variable to receive result.
*
* @return SP_OK upon success, a negative error code otherwise.
*/
enum sp_return sp_get_signals(struct sp_port *port, enum sp_signal *signals);
/**
* Put the port transmit line into the break state.
*
* @param port Pointer to port structure.
*
* @return SP_OK upon success, a negative error code otherwise.
*/
enum sp_return sp_start_break(struct sp_port *port);
/**
* Take the port transmit line out of the break state.
*
* @param port Pointer to port structure.
*
* @return SP_OK upon success, a negative error code otherwise.
*/
enum sp_return sp_end_break(struct sp_port *port);
/**
* @}
* @defgroup Errors Obtaining error information
* @{
*/
/**
* Get the error code for a failed operation.
*
* In order to obtain the correct result, this function should be called
* straight after the failure, before executing any other system operations.
*
* @return The system's numeric code for the error that caused the last
* operation to fail.
*/
int sp_last_error_code(void);
/**
* Get the error message for a failed operation.
*
* In order to obtain the correct result, this function should be called
* straight after the failure, before executing other system operations.
*
* @return The system's message for the error that caused the last
* operation to fail. This string may be allocated by the function,
* and should be freed after use by calling sp_free_error_message().
*/
char *sp_last_error_message(void);
/**
* Free an error message returned by sp_last_error_message().
*/
void sp_free_error_message(char *message);
/**
* Set the handler function for library debugging messages.
*
* Debugging messages are generated by the library during each operation,
* to help in diagnosing problems. The handler will be called for each
* message. The handler can be set to NULL to ignore all debug messages.
*
* The handler function should accept a format string and variable length
* argument list, in the same manner as e.g. printf().
*
* The default handler is sp_default_debug_handler().
*/
void sp_set_debug_handler(void (*handler)(const char *format, ...));
/**
* Default handler function for library debugging messages.
*
* This function prints debug messages to the standard error stream if the
* environment variable LIBSERIALPORT_DEBUG is set. Otherwise, they are
* ignored.
*/
void sp_default_debug_handler(const char *format, ...);
/** @} */
#ifdef __cplusplus
}
#endif
#endif