X-Git-Url: https://sigrok.org/gitweb/?a=blobdiff_plain;f=libserialport.h.in;h=3de68a9830cc325918e5bc64985705cbe544c467;hb=c33efc482e4717af368e22748142f959ac727243;hp=6a76f985fbbacca61664816f96aae5679acde036;hpb=7de20e391530026e9c7bce986dc5d212a48673e8;p=libserialport.git

diff --git a/libserialport.h.in b/libserialport.h.in
index 6a76f98..3de68a9 100644
--- a/libserialport.h.in
+++ b/libserialport.h.in
@@ -49,15 +49,25 @@
  * 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. @ref SP_ERR_ARG
- * indicates the function was called with invalid arguments. @ref SP_ERR_FAIL
- * indicates that the OS reported a failure. @ref SP_ERR_MEM indicates that a
- * memory allocation failed. All of these error values are negative.
+ * All functions can return only four possible error values:
  *
- * When @ref 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.
+ * - @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.
  *
  * Function calls that succeed return @ref SP_OK, which is equal to zero,
  * or where otherwise documented a positive value.
@@ -97,6 +107,8 @@ enum sp_return {
 	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. */
@@ -262,10 +274,10 @@ struct sp_port_config {
  *
  * 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.
+ * 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);
 
@@ -285,10 +297,10 @@ void sp_free_port(struct sp_port *port);
  * 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.
+ * 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);
 
@@ -300,10 +312,10 @@ enum sp_return sp_list_ports(struct sp_port ***list_ptr);
  *
  * 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.
+ * 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);
 
@@ -327,16 +339,14 @@ void sp_free_port_list(struct sp_port **ports);
  * @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.
+ * @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 on success, SP_ERR_FAIL on failure, or SP_ERR_ARG
- *         if an invalid port is passed.
+ * @return SP_OK upon success, a negative error code otherwise.
  */
 enum sp_return sp_close(struct sp_port *port);
 
@@ -356,8 +366,7 @@ enum sp_return sp_close(struct sp_port *port);
  * 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.
+ * @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);
 
@@ -369,8 +378,7 @@ enum sp_return sp_get_config(struct sp_port *port, struct sp_port_config *config
  *
  * 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.
+ * @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);
 
@@ -380,8 +388,7 @@ enum sp_return sp_set_config(struct sp_port *port, const struct sp_port_config *
  * @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.
+ * @return SP_OK upon success, a negative error code otherwise.
  */
 enum sp_return sp_set_baudrate(struct sp_port *port, int baudrate);
 
@@ -391,8 +398,7 @@ enum sp_return sp_set_baudrate(struct sp_port *port, int baudrate);
  * @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.
+ * @return SP_OK upon success, a negative error code otherwise.
  */
 enum sp_return sp_set_bits(struct sp_port *port, int bits);
 
@@ -402,8 +408,7 @@ enum sp_return sp_set_bits(struct sp_port *port, int bits);
  * @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.
+ * @return SP_OK upon success, a negative error code otherwise.
  */
 enum sp_return sp_set_parity(struct sp_port *port, enum sp_parity parity);
 
@@ -413,8 +418,7 @@ enum sp_return sp_set_parity(struct sp_port *port, enum sp_parity parity);
  * @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.
+ * @return SP_OK upon success, a negative error code otherwise.
  */
 enum sp_return sp_set_stopbits(struct sp_port *port, int stopbits);
 
@@ -429,8 +433,7 @@ enum sp_return sp_set_stopbits(struct sp_port *port, int stopbits);
  * @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.
+ * @return SP_OK upon success, a negative error code otherwise.
  */
 enum sp_return sp_set_flowcontrol(struct sp_port *port, enum sp_flowcontrol flowcontrol);
 
@@ -440,8 +443,7 @@ enum sp_return sp_set_flowcontrol(struct sp_port *port, enum sp_flowcontrol flow
  * @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.
+ * @return SP_OK upon success, a negative error code otherwise.
  */
 enum sp_return sp_set_rts(struct sp_port *port, enum sp_rts rts);
 
@@ -451,8 +453,7 @@ enum sp_return sp_set_rts(struct sp_port *port, enum sp_rts rts);
  * @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.
+ * @return SP_OK upon success, a negative error code otherwise.
  */
 enum sp_return sp_set_cts(struct sp_port *port, enum sp_cts cts);
 
@@ -462,8 +463,7 @@ enum sp_return sp_set_cts(struct sp_port *port, enum sp_cts cts);
  * @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.
+ * @return SP_OK upon success, a negative error code otherwise.
  */
 enum sp_return sp_set_dtr(struct sp_port *port, enum sp_dtr dtr);
 
@@ -473,8 +473,7 @@ enum sp_return sp_set_dtr(struct sp_port *port, enum sp_dtr dtr);
  * @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.
+ * @return SP_OK upon success, a negative error code otherwise.
  */
 enum sp_return sp_set_dsr(struct sp_port *port, enum sp_dsr dsr);
 
@@ -484,8 +483,7 @@ enum sp_return sp_set_dsr(struct sp_port *port, enum sp_dsr dsr);
  * @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.
+ * @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);
 
@@ -506,8 +504,7 @@ enum sp_return sp_set_xon_xoff(struct sp_port *port, enum sp_xonxoff xon_xoff);
  * @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.
+ * @return The number of bytes read on success, or a negative error code.
  */
 enum sp_return sp_read(struct sp_port *port, void *buf, size_t count);
 
@@ -522,8 +519,7 @@ enum sp_return sp_read(struct sp_port *port, void *buf, size_t count);
  * @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.
+ * @return The number of bytes written on success, or a negative error code.
  */
 enum sp_return sp_write(struct sp_port *port, const void *buf, size_t count);
 
@@ -533,8 +529,7 @@ enum sp_return sp_write(struct sp_port *port, const void *buf, size_t count);
  * @param port Pointer to port structure.
  * @param buffers Which buffer(s) to flush.
  *
- * @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG
- *         if an invalid port is passed.
+ * @return SP_OK upon success, a negative error code otherwise.
  */
 enum sp_return sp_flush(struct sp_port *port, enum sp_buffer buffers);
 
@@ -543,8 +538,7 @@ enum sp_return sp_flush(struct sp_port *port, enum sp_buffer buffers);
  *
  * @param port Pointer to port structure.
  *
- * @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG
- *         if an invalid port is passed.
+ * @return SP_OK upon success, a negative error code otherwise.
  */
 enum sp_return sp_drain(struct sp_port *port);
 
@@ -565,8 +559,7 @@ enum sp_return sp_drain(struct sp_port *port);
  * @param port Pointer to port structure.
  * @param signals Pointer to variable to receive result.
  *
- * @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG
- *         if an an invalid port or pointer is passed.
+ * @return SP_OK upon success, a negative error code otherwise.
  */
 enum sp_return sp_get_signals(struct sp_port *port, enum sp_signal *signals);
 
@@ -575,8 +568,7 @@ enum sp_return sp_get_signals(struct sp_port *port, enum sp_signal *signals);
  *
  * @param port Pointer to port structure.
  *
- * @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG
- *         if an invalid port is passed.
+ * @return SP_OK upon success, a negative error code otherwise.
  */
 enum sp_return sp_start_break(struct sp_port *port);
 
@@ -585,8 +577,7 @@ enum sp_return sp_start_break(struct sp_port *port);
  *
  * @param port Pointer to port structure.
  *
- * @return SP_OK on success, SP_ERR_FAIL on failure, or SP_ERR_ARG
- *         if an invalid port is passed.
+ * @return SP_OK upon success, a negative error code otherwise.
  */
 enum sp_return sp_end_break(struct sp_port *port);
 
@@ -624,6 +615,29 @@ char *sp_last_error_message(void);
  */
 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