X-Git-Url: https://sigrok.org/gitweb/?a=blobdiff_plain;f=libserialport.h.in;h=93939a680347d027bfa0969338241b337af45fbf;hb=cd5f52812dfbf1f0ec4f72af9a35af2ef02b985a;hp=2f3390569e62910839e1df895f1897d25e979599;hpb=bf2cbd652f9b520dcd3de9c98f000b85de00dba6;p=libserialport.git diff --git a/libserialport.h.in b/libserialport.h.in index 2f33905..93939a6 100644 --- a/libserialport.h.in +++ b/libserialport.h.in @@ -17,6 +17,53 @@ * along with this program. If not, see . */ +/** + +\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: + +- Port enumeration (obtaining a list of serial ports on the system). +- Opening and closing ports. +- Setting port parameters (baud rate, parity, etc). +- Reading, writing and flushing data. +- Obtaining error information. + +libserialport is an open source project released under the LGPL3+ license. + +API +=== + +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. + +All functions can return only three possible error values. SP_ERR_ARG indicates +the function was called with invalid arguments. SP_ERR_FAIL indicates that the +OS reported a failure. SP_ERR_MEM indicates that a memory allocation failed. +All of these error values are negative. + +When SP_ERR_FAIL is returned, an error code or string description of the error +can be obtained by calling sp_last_error_code() or sp_last_error_message(). The +error code or message is that provided by the OS; libserialport does not define +any error codes or messages of its own. + +Function calls that succeed return SP_OK, which is equal to zero, or where +otherwise documented a positive value. + +*/ + #ifndef LIBSERIALPORT_H #define LIBSERIALPORT_H @@ -40,140 +87,427 @@ extern "C" { #define SP_LIB_VERSION_AGE @SP_LIB_VERSION_AGE@ #define SP_LIB_VERSION_STRING "@SP_LIB_VERSION@" -/* A serial port. */ +/** A serial port. */ struct sp_port { - /* Name used to open the port */ + /** Name used to open the port */ char *name; +/** \cond 0 */ /* OS-specific port handle */ #ifdef _WIN32 HANDLE hdl; #else int fd; #endif +/** \endcond */ }; -/* Configuration for a serial port. */ +/** Configuration for a serial port. */ struct sp_port_config { + /** Baud rate in bits per second. */ int baudrate; + /** Number of data bits to use. Valid values are 5 to 8. */ int bits; + /** Parity setting to use. */ int parity; + /** Number of stop bits to use (1 or 2). */ int stopbits; + /** RTS pin mode. */ int rts; + /** CTS pin mode. */ int cts; + /** DTR pin mode. */ int dtr; + /** DSR pin mode. */ int dsr; + /** XON/XOFF flow control mode. */ int xon_xoff; }; -/* Return values. */ + +/** Return values. */ enum { - /* Operation completed successfully. */ + /** Operation completed successfully. */ SP_OK = 0, - /* Invalid arguments were passed to the function. */ + /** Invalid arguments were passed to the function. */ SP_ERR_ARG = -1, - /* A system error occured while executing the operation. */ + /** A system error occured while executing the operation. */ SP_ERR_FAIL = -2, - /* A memory allocation failed while executing the operation. */ + /** A memory allocation failed while executing the operation. */ SP_ERR_MEM = -3, }; -/* Port access modes. */ +/** Port access modes. */ enum { - /* Open port for read/write access. */ + /** Open port for read/write access. */ SP_MODE_RDWR = 1, - /* Open port for read access only. */ + /** Open port for read access only. */ SP_MODE_RDONLY = 2, - /* Open port in non-blocking mode. */ + /** Open port in non-blocking mode. */ SP_MODE_NONBLOCK = 4, }; -/* Parity settings. */ +/** Parity settings. */ enum { - /* No parity. */ + /** No parity. */ SP_PARITY_NONE = 0, - /* Even parity. */ + /** Even parity. */ SP_PARITY_EVEN = 1, - /* Odd parity. */ + /** Odd parity. */ SP_PARITY_ODD = 2, }; -/* RTS pin behaviour. */ +/** RTS pin behaviour. */ enum { + /** 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. */ +/** CTS pin behaviour. */ enum { + /** CTS ignored. */ SP_CTS_IGNORE = 0, + /** CTS used for flow control. */ SP_CTS_FLOW_CONTROL = 1 }; -/* DTR pin behaviour. */ +/** DTR pin behaviour. */ enum { + /** 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. */ +/** DSR pin behaviour. */ enum { + /** DSR ignored. */ SP_DSR_IGNORE = 0, + /** DSR used for flow control. */ SP_DSR_FLOW_CONTROL = 1 }; -/* XON/XOFF flow control behaviour. */ +/** XON/XOFF flow control behaviour. */ enum { + /** 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. */ +/** Standard flow control combinations. */ enum { + /** 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 }; -/* Enumeration */ +/** + Obtains 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(). + + @return SP_OK on success, SP_ERR_FAIL on failure, SP_ERR_MEM on allocation + failure, or SP_ERR_ARG if an invalid pointer is passed. 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. +*/ int sp_get_port_by_name(const char *portname, struct sp_port **port_ptr); + +/** +Frees a port structure obtained from sp_get_port_by_name() or sp_copy_port(). +*/ void sp_free_port(struct sp_port *port); + +/** + Lists 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(). + + @return SP_OK on success, SP_ERR_FAIL on failure, SP_ERR_MEM on allocation + failure, or SP_ERR_ARG if an invalid pointer is passed. 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. +*/ int sp_list_ports(struct sp_port ***list_ptr); + +/** + Makes 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(). + + @return SP_OK on success, SP_ERR_MEM on allocation failure, or SP_ERR_ARG + if an invalid port or pointer is passed. 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. +*/ int sp_copy_port(const struct sp_port *port, struct sp_port **copy_ptr); + +/** + Frees 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); -/* Opening & closing ports */ +/** + Opens the specified serial port. + + @param port Pointer to port structure. + @param flags Flags to use when opening the serial port. Possible + flags are: SP_MODE_RDWR, SP_MODE_RDONLY, and + SP_MODE_NONBLOCK. + + @return SP_OK on success, SP_ERR_FAIL on failure, SP_ERR_MEM on allocation + failure, or SP_ERR_ARG if an invalid port is passed. +*/ int sp_open(struct sp_port *port, int flags); + +/** + Closes the specified serial port. + + @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG + if an invalid port is passed. +*/ int sp_close(struct sp_port *port); -/* Reading, writing and flushing. */ +/** + Reads bytes from the specified serial port. Note that this function may + return after reading less than the specified number of bytes; it is the + user's responsibility to iterate as necessary in this case. + + @param port Pointer to port structure. + @param buf Buffer in which to store the bytes read. + @param count Maximum number of bytes to read. + + @return The number of bytes read, SP_ERR_FAIL on failure, + or SP_ERR_ARG for invalid arguments. +*/ int sp_read(struct sp_port *port, void *buf, size_t count); + +/** + Write bytes to the specified serial port. Note that this function may + return after writing less than the specified number of bytes; it is the + user's responsibility to iterate as necessary in this case. + + @param port Pointer to port structure. + @param buf Buffer containing the bytes to write. + @param count Maximum number of bytes to write. + + @return The number of bytes written, SP_ERR_FAIL on failure, + or SP_ERR_ARG for invalid arguments. +*/ int sp_write(struct sp_port *port, const void *buf, size_t count); + +/** + Flushes serial port buffers. + + @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG + if an invalid port is passed. +*/ int sp_flush(struct sp_port *port); -/* Basic port configuration */ +/** + Gets current configuration of the specified serial port. + + The user should allocate a struct sp_port_config, then pass a pointer to it + as the config parameter. The struct will be populated with the port + configuration. + + @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG + for invalid arguments. +*/ int sp_get_config(struct sp_port *port, struct sp_port_config *config); + +/** + Sets all parameters for the specified serial port. + + The user should populate a struct sp_port_config, then pass a pointer to it + as the config parameter. + + To retain the current value of any setting, set the field to to a + negative value. + + @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG + for invalid arguments. +*/ int sp_set_config(struct sp_port *port, const struct sp_port_config *config); + +/** + Sets the baud rate for the specified serial port. + + @param port Pointer to port structure. + @param baud Baud rate in bits per second. + + @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG + for invalid arguments. +*/ int sp_set_baudrate(struct sp_port *port, int baudrate); + +/** + Sets the number of data bits for the specified serial port. + + @param port Pointer to port structure. + @param bits Number of data bits to use. Valid values are 5 to 8. + + @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG + for invalid arguments. +*/ int sp_set_bits(struct sp_port *port, int bits); + +/** + Sets the parity for the specified serial port. + + @param port Pointer to port structure. + @param parity Parity setting to use. + (SP_PARITY_NONE, SP_PARITY_EVEN or SP_PARITY_ODD) + + @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG + for invalid arguments. +*/ int sp_set_parity(struct sp_port *port, int parity); + +/** + Sets the number of stop bits for the specified port. + + @param port Pointer to port structure. + @param stopbits Number of stop bits to use (1 or 2). + + @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG + for invalid arguments. +*/ int sp_set_stopbits(struct sp_port *port, int stopbits); + +/** + Sets the flow control type for the specified serial port. + + This function is a wrapper that sets the RTS, CTS, DTR, DSR and + XON/XOFF settings as necessary for the specified flow control + type. For more fine-grained control of these settings, use their + individual configuration functions or the sp_set_config() function. + + @param port Pointer to port structure. + @param flowcontrol Flow control setting to use. Valid settings are: + + SP_FLOWCONTROL_NONE: No flow control. + SP_FLOWCONTROL_XONXOFF: Software flow control using XON/XOFF characters. + SP_FLOWCONTROL_RTSCTS: Hardware flow control using RTS/CTS signals. + SP_FLOWCONTROL_DTRDSR: Hardware flow control using DTR/DSR signals. + + @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG + for invalid arguments. +*/ int sp_set_flowcontrol(struct sp_port *port, int flowcontrol); -/* Advanced port configuration */ +/** + Sets the RTS pin behaviour for the specified port. + + @param port Pointer to port structure. + @param rts RTS pin mode. + (SP_RTS_ON, SP_RTS_OFF or SP_RTS_FLOW_CONTROL) + + @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG + for invalid arguments. +*/ int sp_set_rts(struct sp_port *port, int rts); + +/** + Sets the CTS pin behaviour for the specified port. + + @param port Pointer to port structure. + @param cts CTS pin mode. + (SP_CTS_IGNORE or SP_CTS_FLOW_CONTROL) + + @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG + for invalid arguments. +*/ int sp_set_cts(struct sp_port *port, int cts); + +/** + Sets the DTR pin behaviour for the specified port. + + @param port Pointer to port structure. + @param dtr DTR pin mode. + (SP_DTR_ON, SP_DTR_OFF or SP_DTR_FLOW_CONTROL) + + @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG + for invalid arguments. +*/ int sp_set_dtr(struct sp_port *port, int dtr); + +/** + Sets the RTS pin behaviour for the specified port. + + @param port Pointer to port structure. + @param dsr DSR pin mode. + (SP_DSR_IGNORE or SP_DSR_FLOW_CONTROL) + + @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG + for invalid arguments. +*/ int sp_set_dsr(struct sp_port *port, int dsr); + +/** + Configures XON/XOFF flow control for the specified port. + + @param port Pointer to port structure. + @param xon_xoff XON/XOFF flow control mode. + (SP_XONXOFF_DISABLED, SP_XONXOFF_IN, + SP_XONXOFF_OUT or SP_XONXOFF_INOUT) + + @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG + for invalid arguments. +*/ int sp_set_xon_xoff(struct sp_port *port, int xon_xoff); -/* Error handling */ +/** + Gets 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); + +/** + Gets 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); + +/** + Frees an error message returned by sp_last_error_message(). +*/ void sp_free_error_message(char *message); #ifdef __cplusplus @@ -181,3 +515,4 @@ void sp_free_error_message(char *message); #endif #endif /* LIBSERIALPORT_H */ +