X-Git-Url: http://sigrok.org/gitweb/?a=blobdiff_plain;ds=sidebyside;f=libserialport.h.in;h=275bcee8d301441c69c7625f6ea5567e0731b686;hb=626d280fd3d4a12910a38041bf98bb2e962f3dcc;hp=9eb5e0cc626f477cb5250c95caa265f28db400ab;hpb=d1202734fb67690997f5a74c236f4f1f7d1d2256;p=libserialport.git diff --git a/libserialport.h.in b/libserialport.h.in index 9eb5e0c..275bcee 100644 --- a/libserialport.h.in +++ b/libserialport.h.in @@ -17,6 +17,54 @@ * 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: + +- @ref Enumeration (obtaining a list of serial ports on the system). +- @ref Ports +- @ref Configuration (baud rate, parity, 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. + +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 @@ -40,88 +88,464 @@ extern "C" { #define SP_LIB_VERSION_AGE @SP_LIB_VERSION_AGE@ #define SP_LIB_VERSION_STRING "@SP_LIB_VERSION@" -/* A serial port. */ +/** 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, +}; + +/** Port access modes. */ +enum sp_mode { + /** Open port for read/write access. */ + SP_MODE_RDWR = 1, + /** Open port for read access only. */ + SP_MODE_RDONLY = 2, + /** Open port in non-blocking mode. */ + SP_MODE_NONBLOCK = 4, +}; + +/** Parity settings. */ +enum sp_parity { + /** Special value to indicate setting should be left alone. */ + SP_PARITY_INVALID = -1, + /** No parity. */ + SP_PARITY_NONE = 0, + /** Even parity. */ + SP_PARITY_EVEN = 1, + /** Odd parity. */ + SP_PARITY_ODD = 2, +}; + +/** 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 +}; + +/** 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; - int parity; + /** Parity setting to use. */ + enum sp_parity parity; + /** Number of stop bits to use (1 or 2). */ int stopbits; - int flowcontrol; - int rts; - int dtr; -}; - -/* Return values. */ -enum { - /* 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, + /** RTS pin mode. */ + enum sp_rts rts; + /** CTS pin mode. */ + enum sp_cts cts; + /** DTR pin mode. */ + enum sp_dtr dtr; + /** DSR pin mode. */ + enum sp_dsr dsr; + /** XON/XOFF flow control mode. */ + enum sp_xonxoff xon_xoff; }; -/* Port access modes. */ -enum { - /* Open port for read/write access. */ - SP_MODE_RDWR = 1, - /* Open port for read access only. */ - SP_MODE_RDONLY = 2, - /* Open port in non-blocking mode. */ - SP_MODE_NONBLOCK = 4, -}; +/** +@defgroup Enumeration Port enumeration +@{ +*/ -/* Parity settings. */ -enum { - /* No parity. */ - SP_PARITY_NONE = 0, - /* Even parity. */ - SP_PARITY_EVEN = 1, - /* Odd parity. */ - SP_PARITY_ODD = 2, -}; +/** + 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. -/* Flow control settings. */ -enum { - /* No flow control. */ - SP_FLOW_NONE = 0, - /* Hardware (RTS/CTS) flow control. */ - SP_FLOW_HARDWARE = 1, - /* Software (XON/XOFF) flow control. */ - SP_FLOW_SOFTWARE = 2, -}; + 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. +*/ +enum sp_return sp_get_port_by_name(const char *portname, struct sp_port **port_ptr); -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); -int sp_list_ports(struct sp_port ***list_ptr); -int sp_copy_port(const struct sp_port *port, struct sp_port **copy_ptr); + +/** + 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. +*/ +enum sp_return 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. +*/ +enum sp_return 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); -int sp_open(struct sp_port *port, int flags); -int sp_close(struct sp_port *port); -int sp_flush(struct sp_port *port); -int sp_write(struct sp_port *port, const void *buf, size_t count); -int sp_read(struct sp_port *port, void *buf, size_t count); -int sp_set_config(struct sp_port *port, struct sp_port_config *config); + +/** + @} +@defgroup 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. + + @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. +*/ +enum sp_return sp_open(struct sp_port *port, enum sp_mode 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. +*/ +enum sp_return sp_close(struct sp_port *port); + +/** + @} +@defgroup Configuration Setting port parameters +@{ +*/ + +/** + 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. + + Any setting that is in a state not recognised or supported by + libserialport will have its value set to -1 in the struct. + + @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG + for invalid arguments. +*/ +enum sp_return sp_get_config(struct sp_port *port, struct sp_port_config *config); + +/** + Sets configuration 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 that field to -1. + + @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG + for invalid arguments. +*/ +enum sp_return 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 baudrate Baud rate in bits per second. + + @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG + for invalid arguments. +*/ +enum sp_return 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. +*/ +enum sp_return 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. + + @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG + for invalid arguments. +*/ +enum sp_return sp_set_parity(struct sp_port *port, enum sp_parity 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. +*/ +enum sp_return 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. + + @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG + for invalid arguments. +*/ +enum sp_return sp_set_flowcontrol(struct sp_port *port, enum sp_flowcontrol flowcontrol); + +/** + Sets the RTS pin behaviour for the specified port. + + @param port Pointer to port structure. + @param rts RTS pin mode. + + @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG + for invalid arguments. +*/ +enum sp_return sp_set_rts(struct sp_port *port, enum sp_rts rts); + +/** + Sets the CTS pin behaviour for the specified port. + + @param port Pointer to port structure. + @param cts CTS pin mode. + + @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG + for invalid arguments. +*/ +enum sp_return sp_set_cts(struct sp_port *port, enum sp_cts cts); + +/** + Sets the DTR pin behaviour for the specified port. + + @param port Pointer to port structure. + @param dtr DTR pin mode. + + @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG + for invalid arguments. +*/ +enum sp_return sp_set_dtr(struct sp_port *port, enum sp_dtr dtr); + +/** + Sets the RTS pin behaviour for the specified port. + + @param port Pointer to port structure. + @param dsr DSR pin mode. + + @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG + for invalid arguments. +*/ +enum sp_return sp_set_dsr(struct sp_port *port, enum sp_dsr dsr); + +/** + Configures XON/XOFF flow control for the specified port. + + @param port Pointer to port structure. + @param xon_xoff XON/XOFF flow control mode. + + @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG + for invalid arguments. +*/ +enum sp_return sp_set_xon_xoff(struct sp_port *port, enum sp_xonxoff xon_xoff); + +/** + @} +@defgroup Data Reading, writing & flushing data +@{ +*/ + +/** + 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. +*/ +enum sp_return 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. +*/ +enum sp_return 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. +*/ +enum sp_return sp_flush(struct sp_port *port); + +/** + @} +@defgroup Errors Obtaining error information +@{ +*/ + +/** + 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 } #endif #endif /* LIBSERIALPORT_H */ +