* Get the USB bus number and address on bus of a USB serial adapter port.
*
* @param[in] port Pointer to a port structure. Must not be NULL.
- * @param[out] usb_bus Pointer to a variable to store the USB bus. Must not be NULL.
- * @param[out] usb_address Pointer to a variable to store the USB address. Must not be NULL.
+ * @param[out] usb_bus Pointer to a variable to store the USB bus.
+ * Can be NULL (in that case it will be ignored).
+ * @param[out] usb_address Pointer to a variable to store the USB address.
+ * Can be NULL (in that case it will be ignored).
*
* @return SP_OK upon success, a negative error code otherwise.
*
* Get the USB Vendor ID and Product ID of a USB serial adapter port.
*
* @param[in] port Pointer to a port structure. Must not be NULL.
- * @param[out] usb_vid Pointer to a variable to store the USB VID. Must not be NULL.
- * @param[out] usb_pid Pointer to a variable to store the USB PID. Must not be NULL.
+ * @param[out] usb_vid Pointer to a variable to store the USB VID.
+ * Can be NULL (in that case it will be ignored).
+ * @param[out] usb_pid Pointer to a variable to store the USB PID.
+ * Can be NULL (in that case it will be ignored).
*
* @return SP_OK upon success, a negative error code otherwise.
*
*
* @param[in] port Pointer to a port structure. Must not be NULL.
* @param[out] result_ptr If any error is returned, the variable pointed to by
- * result_ptr will be set to NULL. Otherwise, it will
- * be set to point to the OS handle. Must not be NULL.
+ * result_ptr will have unknown contents and should not
+ * be used. Otherwise, it will be set to point to the
+ * OS handle. Must not be NULL.
*
* @return SP_OK upon success, a negative error code otherwise.
*
/**
* 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.
+ * The user should allocate a variable of type "struct sp_port_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[out] config_ptr Pointer to a variable to receive the result.
+ * @param[out] config_ptr If any error is returned, the variable pointed to by
+ * config_ptr will be set to NULL. Otherwise, it will
+ * be set to point to the allocated config structure.
* Must not be NULL.
*
* @return SP_OK upon success, a negative error code otherwise.
*
* @param[in] port Pointer to a port structure. Must not be NULL.
* @param[out] config Pointer to a configuration structure that will hold
- * the result. Must not be NULL.
+ * the result. Upon errors the contents of the config
+ * struct will not be changed. Must not be NULL.
*
* @return SP_OK upon success, a negative error code otherwise.
*
* -1, but see the documentation for each field). These values will be ignored
* and the corresponding setting left unchanged on the port.
*
+ * Upon errors, the configuration of the serial port is unknown since
+ * partial/incomplete config updates may have happened.
+ *
* @param[in] port Pointer to a port structure. Must not be NULL.
* @param[in] config Pointer to a configuration structure. Must not be NULL.
*
*/
enum sp_return sp_blocking_read(struct sp_port *port, void *buf, size_t count, unsigned int timeout_ms);
+/**
+ * Read bytes from the specified serial port, returning as soon as any data is
+ * available.
+ *
+ * @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[in] port Pointer to a port structure. Must not be NULL.
+ * @param[out] buf Buffer in which to store the bytes read. Must not be NULL.
+ * @param[in] count Maximum number of bytes to read. Must not be zero.
+ * @param[in] timeout_ms Timeout in milliseconds, or zero to wait indefinitely.
+ *
+ * @return The number of bytes read on success, or a negative error code. If
+ * the result is zero, the timeout was reached before any bytes were
+ * available. If timeout_ms is zero, the function will always return
+ * either at least one byte, or a negative error code.
+ *
+ * @since 0.1.1
+ */
+enum sp_return sp_blocking_read_next(struct sp_port *port, void *buf, size_t count, unsigned int timeout_ms);
+
/**
* Read bytes from the specified serial port, without blocking.
*
*
* In order to obtain the correct result, this function should be called
* straight after the failure, before executing any other system operations.
+ * The result is thread-specific, and only valid when called immediately
+ * after a previous call returning SP_ERR_FAIL.
*
* @return The system's numeric code for the error that caused the last
* operation to fail.
*
* In order to obtain the correct result, this function should be called
* straight after the failure, before executing other system operations.
+ * The result is thread-specific, and only valid when called immediately
+ * after a previous call returning SP_ERR_FAIL.
*
* @return The system's message for the error that caused the last
* operation to fail. This string may be allocated by the function,