X-Git-Url: http://sigrok.org/gitweb/?p=libserialport.git;a=blobdiff_plain;f=serialport.c;h=272bdf6013a525b96a30cd869ea3e99ca0ea0499;hp=8408ec7efb7d892d06399e329c9d00041fd7926f;hb=ad036cc8efcdcae5d2b8727996108c38c4915d2b;hpb=31b3a8f5b52aa90cf3795679da626255fd21c67a

diff --git a/serialport.c b/serialport.c
index 8408ec7..272bdf6 100644
--- a/serialport.c
+++ b/serialport.c
@@ -5,6 +5,7 @@
  * Copyright (C) 2010-2012 Uwe Hermann <uwe@hermann-uwe.de>
  * Copyright (C) 2013 Martin Ling <martin-libserialport@earth.li>
  * Copyright (C) 2013 Matthias Heidbrink <m-sigrok@heidbrink.biz>
+ * Copyright (C) 2014 Aurelien Jacobs <aurel@gnuage.org>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License as
@@ -20,58 +21,10 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include <string.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-#include <unistd.h>
-#include <stdlib.h>
-#include <errno.h>
-#ifdef _WIN32
-#include <windows.h>
-#include <tchar.h>
-#include <stdio.h>
-#else
-#include <termios.h>
-#include <sys/ioctl.h>
-#endif
-#ifdef __APPLE__
-#include <IOKit/IOKitLib.h>
-#include <IOKit/serial/IOSerialKeys.h>
-#include <IOKit/serial/ioss.h>
-#include <sys/syslimits.h>
-#endif
-#ifdef __linux__
-#include "libudev.h"
-#include "linux/serial.h"
-#endif
-
 #include "libserialport.h"
+#include "libserialport_internal.h"
 
-struct port_data {
-#ifdef _WIN32
-	DCB dcb;
-#else
-	struct termios term;
-	int controlbits;
-#endif
-};
-
-/* Standard baud rates. */
-#ifdef _WIN32
-#define BAUD_TYPE DWORD
-#define BAUD(n) {CBR_##n, n}
-#else
-#define BAUD_TYPE speed_t
-#define BAUD(n) {B##n, n}
-#endif
-
-struct std_baudrate {
-	BAUD_TYPE index;
-	int value;
-};
-
-const struct std_baudrate std_baudrates[] = {
+static const struct std_baudrate std_baudrates[] = {
 #ifdef _WIN32
 	/*
 	 * The baudrates 50/75/134/150/200/1800/230400/460800 do not seem to
@@ -91,78 +44,264 @@ const struct std_baudrate std_baudrates[] = {
 #endif
 };
 
-#define ARRAY_SIZE(x) (sizeof(x) / sizeof(x[0]))
 #define NUM_STD_BAUDRATES ARRAY_SIZE(std_baudrates)
 
-/* Helper functions. */
-static enum sp_return validate_port(struct sp_port *port);
-static struct sp_port **list_append(struct sp_port **list, const char *portname);
+void (*sp_debug_handler)(const char *format, ...) = sp_default_debug_handler;
+
 static enum sp_return get_config(struct sp_port *port, struct port_data *data,
 	struct sp_port_config *config);
+
 static enum sp_return set_config(struct sp_port *port, struct port_data *data,
 	const struct sp_port_config *config);
 
-enum sp_return sp_get_port_by_name(const char *portname, struct sp_port **port_ptr)
+SP_API enum sp_return sp_get_port_by_name(const char *portname, struct sp_port **port_ptr)
 {
 	struct sp_port *port;
+#ifndef NO_PORT_METADATA
+	enum sp_return ret;
+#endif
 	int len;
 
+	TRACE("%s, %p", portname, port_ptr);
+
 	if (!port_ptr)
-		return SP_ERR_ARG;
+		RETURN_ERROR(SP_ERR_ARG, "Null result pointer");
 
 	*port_ptr = NULL;
 
 	if (!portname)
-		return SP_ERR_ARG;
+		RETURN_ERROR(SP_ERR_ARG, "Null port name");
+
+	DEBUG_FMT("Building structure for port %s", portname);
 
 	if (!(port = malloc(sizeof(struct sp_port))))
-		return SP_ERR_MEM;
+		RETURN_ERROR(SP_ERR_MEM, "Port structure malloc failed");
 
 	len = strlen(portname) + 1;
 
 	if (!(port->name = malloc(len))) {
 		free(port);
-		return SP_ERR_MEM;
+		RETURN_ERROR(SP_ERR_MEM, "Port name malloc failed");
 	}
 
 	memcpy(port->name, portname, len);
 
 #ifdef _WIN32
+	port->usb_path = NULL;
 	port->hdl = INVALID_HANDLE_VALUE;
 #else
 	port->fd = -1;
 #endif
 
+	port->description = NULL;
+	port->transport = SP_TRANSPORT_NATIVE;
+	port->usb_bus = -1;
+	port->usb_address = -1;
+	port->usb_vid = -1;
+	port->usb_pid = -1;
+	port->usb_manufacturer = NULL;
+	port->usb_product = NULL;
+	port->usb_serial = NULL;
+	port->bluetooth_address = NULL;
+
+#ifndef NO_PORT_METADATA
+	if ((ret = get_port_details(port)) != SP_OK) {
+		sp_free_port(port);
+		return ret;
+	}
+#endif
+
 	*port_ptr = port;
 
-	return SP_OK;
+	RETURN_OK();
+}
+
+SP_API char *sp_get_port_name(const struct sp_port *port)
+{
+	TRACE("%p", port);
+
+	if (!port)
+		return NULL;
+
+	RETURN_STRING(port->name);
 }
 
-enum sp_return sp_copy_port(const struct sp_port *port, struct sp_port **copy_ptr)
+SP_API char *sp_get_port_description(struct sp_port *port)
 {
+	TRACE("%p", port);
+
+	if (!port || !port->description)
+		return NULL;
+
+	RETURN_STRING(port->description);
+}
+
+SP_API enum sp_transport sp_get_port_transport(const struct sp_port *port)
+{
+	TRACE("%p", port);
+
+	if (!port)
+		RETURN_ERROR(SP_ERR_ARG, "Null port");
+
+	RETURN_INT(port->transport);
+}
+
+SP_API enum sp_return sp_get_port_usb_bus_address(const struct sp_port *port,
+                                                  int *usb_bus,int *usb_address)
+{
+	TRACE("%p", port);
+
+	if (!port)
+		RETURN_ERROR(SP_ERR_ARG, "Null port");
+	if (port->transport != SP_TRANSPORT_USB)
+		RETURN_ERROR(SP_ERR_ARG, "Port does not use USB transport");
+	if (port->usb_bus < 0 || port->usb_address < 0)
+		RETURN_ERROR(SP_ERR_SUPP, "Bus and address values are not available");
+
+	if (usb_bus)
+		*usb_bus = port->usb_bus;
+	if (usb_address)
+		*usb_address = port->usb_address;
+
+	RETURN_OK();
+}
+
+SP_API enum sp_return sp_get_port_usb_vid_pid(const struct sp_port *port,
+                                              int *usb_vid, int *usb_pid)
+{
+	TRACE("%p", port);
+
+	if (!port)
+		RETURN_ERROR(SP_ERR_ARG, "Null port");
+	if (port->transport != SP_TRANSPORT_USB)
+		RETURN_ERROR(SP_ERR_ARG, "Port does not use USB transport");
+	if (port->usb_vid < 0 || port->usb_pid < 0)
+		RETURN_ERROR(SP_ERR_SUPP, "VID:PID values are not available");
+
+	if (usb_vid)
+		*usb_vid = port->usb_vid;
+	if (usb_pid)
+		*usb_pid = port->usb_pid;
+
+	RETURN_OK();
+}
+
+SP_API char *sp_get_port_usb_manufacturer(const struct sp_port *port)
+{
+	TRACE("%p", port);
+
+	if (!port || port->transport != SP_TRANSPORT_USB || !port->usb_manufacturer)
+		return NULL;
+
+	RETURN_STRING(port->usb_manufacturer);
+}
+
+SP_API char *sp_get_port_usb_product(const struct sp_port *port)
+{
+	TRACE("%p", port);
+
+	if (!port || port->transport != SP_TRANSPORT_USB || !port->usb_product)
+		return NULL;
+
+	RETURN_STRING(port->usb_product);
+}
+
+SP_API char *sp_get_port_usb_serial(const struct sp_port *port)
+{
+	TRACE("%p", port);
+
+	if (!port || port->transport != SP_TRANSPORT_USB || !port->usb_serial)
+		return NULL;
+
+	RETURN_STRING(port->usb_serial);
+}
+
+SP_API char *sp_get_port_bluetooth_address(const struct sp_port *port)
+{
+	TRACE("%p", port);
+
+	if (!port || port->transport != SP_TRANSPORT_BLUETOOTH
+	    || !port->bluetooth_address)
+		return NULL;
+
+	RETURN_STRING(port->bluetooth_address);
+}
+
+SP_API enum sp_return sp_get_port_handle(const struct sp_port *port,
+                                         void *result_ptr)
+{
+	TRACE("%p, %p", port, result_ptr);
+
+	if (!port)
+		RETURN_ERROR(SP_ERR_ARG, "Null port");
+
+#ifdef _WIN32
+	HANDLE *handle_ptr = result_ptr;
+	*handle_ptr = port->hdl;
+#else
+	int *fd_ptr = result_ptr;
+	*fd_ptr = port->fd;
+#endif
+
+	RETURN_OK();
+}
+
+SP_API enum sp_return sp_copy_port(const struct sp_port *port,
+                                   struct sp_port **copy_ptr)
+{
+	TRACE("%p, %p", port, copy_ptr);
+
 	if (!copy_ptr)
-		return SP_ERR_ARG;
+		RETURN_ERROR(SP_ERR_ARG, "Null result pointer");
 
 	*copy_ptr = NULL;
 
-	if (!port || !port->name)
-		return SP_ERR_ARG;
+	if (!port)
+		RETURN_ERROR(SP_ERR_ARG, "Null port");
 
-	return sp_get_port_by_name(port->name, copy_ptr);
+	if (!port->name)
+		RETURN_ERROR(SP_ERR_ARG, "Null port name");
+
+	DEBUG("Copying port structure");
+
+	RETURN_INT(sp_get_port_by_name(port->name, copy_ptr));
 }
 
-void sp_free_port(struct sp_port *port)
+SP_API void sp_free_port(struct sp_port *port)
 {
-	if (!port)
-		return;
+	TRACE("%p", port);
+
+	if (!port) {
+		DEBUG("Null port");
+		RETURN();
+	}
+
+	DEBUG("Freeing port structure");
 
 	if (port->name)
 		free(port->name);
+	if (port->description)
+		free(port->description);
+	if (port->usb_manufacturer)
+		free(port->usb_manufacturer);
+	if (port->usb_product)
+		free(port->usb_product);
+	if (port->usb_serial)
+		free(port->usb_serial);
+	if (port->bluetooth_address)
+		free(port->bluetooth_address);
+#ifdef _WIN32
+	if (port->usb_path)
+		free(port->usb_path);
+#endif
 
 	free(port);
+
+	RETURN();
 }
 
-static struct sp_port **list_append(struct sp_port **list, const char *portname)
+SP_PRIV struct sp_port **list_append(struct sp_port **list,
+                                     const char *portname)
 {
 	void *tmp;
 	unsigned int count;
@@ -181,391 +320,1125 @@ fail:
 	return NULL;
 }
 
-enum sp_return sp_list_ports(struct sp_port ***list_ptr)
+SP_API enum sp_return sp_list_ports(struct sp_port ***list_ptr)
 {
+#ifndef NO_ENUMERATION
 	struct sp_port **list;
-	int ret = SP_OK;
+	int ret;
+#endif
+
+	TRACE("%p", list_ptr);
+
+	if (!list_ptr)
+		RETURN_ERROR(SP_ERR_ARG, "Null result pointer");
+
+#ifdef NO_ENUMERATION
+	RETURN_ERROR(SP_ERR_SUPP, "Enumeration not supported on this platform");
+#else
+	DEBUG("Enumerating ports");
 
-	if (!(list = malloc(sizeof(struct sp_port **))))
-		return SP_ERR_MEM;
+	if (!(list = malloc(sizeof(struct sp_port *))))
+		RETURN_ERROR(SP_ERR_MEM, "Port list malloc failed");
 
 	list[0] = NULL;
 
+	ret = list_ports(&list);
+
+	if (ret == SP_OK) {
+		*list_ptr = list;
+	} else {
+		sp_free_port_list(list);
+		*list_ptr = NULL;
+	}
+
+	RETURN_CODEVAL(ret);
+#endif
+}
+
+SP_API void sp_free_port_list(struct sp_port **list)
+{
+	unsigned int i;
+
+	TRACE("%p", list);
+
+	if (!list) {
+		DEBUG("Null list");
+		RETURN();
+	}
+
+	DEBUG("Freeing port list");
+
+	for (i = 0; list[i]; i++)
+		sp_free_port(list[i]);
+	free(list);
+
+	RETURN();
+}
+
+#define CHECK_PORT() do { \
+	if (!port) \
+		RETURN_ERROR(SP_ERR_ARG, "Null port"); \
+	if (!port->name) \
+		RETURN_ERROR(SP_ERR_ARG, "Null port name"); \
+} while (0)
 #ifdef _WIN32
-	HKEY key;
-	TCHAR *value, *data;
-	DWORD max_value_len, max_data_size, max_data_len;
-	DWORD value_len, data_size, data_len;
-	DWORD type, index = 0;
-	char *name;
-	int name_len;
-
-	if (RegOpenKeyEx(HKEY_LOCAL_MACHINE, _T("HARDWARE\\DEVICEMAP\\SERIALCOMM"),
-			0, KEY_QUERY_VALUE, &key) != ERROR_SUCCESS) {
-		ret = SP_ERR_FAIL;
-		goto out_done;
+#define CHECK_PORT_HANDLE() do { \
+	if (port->hdl == INVALID_HANDLE_VALUE) \
+		RETURN_ERROR(SP_ERR_ARG, "Invalid port handle"); \
+} while (0)
+#else
+#define CHECK_PORT_HANDLE() do { \
+	if (port->fd < 0) \
+		RETURN_ERROR(SP_ERR_ARG, "Invalid port fd"); \
+} while (0)
+#endif
+#define CHECK_OPEN_PORT() do { \
+	CHECK_PORT(); \
+	CHECK_PORT_HANDLE(); \
+} while (0)
+
+#ifdef WIN32
+/** To be called after port receive buffer is emptied. */
+static enum sp_return restart_wait(struct sp_port *port)
+{
+	DWORD wait_result;
+
+	if (port->wait_running) {
+		/* Check status of running wait operation. */
+		if (GetOverlappedResult(port->hdl, &port->wait_ovl,
+				&wait_result, FALSE)) {
+			DEBUG("Previous wait completed");
+			port->wait_running = FALSE;
+		} else if (GetLastError() == ERROR_IO_INCOMPLETE) {
+			DEBUG("Previous wait still running");
+			RETURN_OK();
+		} else {
+			RETURN_FAIL("GetOverlappedResult() failed");
+		}
 	}
-	if (RegQueryInfoKey(key, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
-				&max_value_len, &max_data_size, NULL, NULL) != ERROR_SUCCESS) {
-		ret = SP_ERR_FAIL;
-		goto out_close;
+
+	if (!port->wait_running) {
+		/* Start new wait operation. */
+		if (WaitCommEvent(port->hdl, &port->events,
+				&port->wait_ovl)) {
+			DEBUG("New wait returned, events already pending");
+		} else if (GetLastError() == ERROR_IO_PENDING) {
+			DEBUG("New wait running in background");
+			port->wait_running = TRUE;
+		} else {
+			RETURN_FAIL("WaitCommEvent() failed");
+		}
+	}
+
+	RETURN_OK();
+}
+#endif
+
+SP_API enum sp_return sp_open(struct sp_port *port, enum sp_mode flags)
+{
+	struct port_data data;
+	struct sp_port_config config;
+	enum sp_return ret;
+
+	TRACE("%p, 0x%x", port, flags);
+
+	CHECK_PORT();
+
+	if (flags > SP_MODE_READ_WRITE)
+		RETURN_ERROR(SP_ERR_ARG, "Invalid flags");
+
+	DEBUG_FMT("Opening port %s", port->name);
+
+#ifdef _WIN32
+	DWORD desired_access = 0, flags_and_attributes = 0, errors;
+	char *escaped_port_name;
+	COMSTAT status;
+
+	/* Prefix port name with '\\.\' to work with ports above COM9. */
+	if (!(escaped_port_name = malloc(strlen(port->name) + 5)))
+		RETURN_ERROR(SP_ERR_MEM, "Escaped port name malloc failed");
+	sprintf(escaped_port_name, "\\\\.\\%s", port->name);
+
+	/* Map 'flags' to the OS-specific settings. */
+	flags_and_attributes = FILE_ATTRIBUTE_NORMAL | FILE_FLAG_OVERLAPPED;
+	if (flags & SP_MODE_READ)
+		desired_access |= GENERIC_READ;
+	if (flags & SP_MODE_WRITE)
+		desired_access |= GENERIC_WRITE;
+
+	port->hdl = CreateFile(escaped_port_name, desired_access, 0, 0,
+			 OPEN_EXISTING, flags_and_attributes, 0);
+
+	free(escaped_port_name);
+
+	if (port->hdl == INVALID_HANDLE_VALUE)
+		RETURN_FAIL("Port CreateFile() failed");
+
+	/* All timeouts initially disabled. */
+	port->timeouts.ReadIntervalTimeout = 0;
+	port->timeouts.ReadTotalTimeoutMultiplier = 0;
+	port->timeouts.ReadTotalTimeoutConstant = 0;
+	port->timeouts.WriteTotalTimeoutMultiplier = 0;
+	port->timeouts.WriteTotalTimeoutConstant = 0;
+
+	if (SetCommTimeouts(port->hdl, &port->timeouts) == 0) {
+		sp_close(port);
+		RETURN_FAIL("SetCommTimeouts() failed");
+	}
+
+	/* Prepare OVERLAPPED structures. */
+#define INIT_OVERLAPPED(ovl) do { \
+	memset(&port->ovl, 0, sizeof(port->ovl)); \
+	port->ovl.hEvent = INVALID_HANDLE_VALUE; \
+	if ((port->ovl.hEvent = CreateEvent(NULL, TRUE, TRUE, NULL)) \
+			== INVALID_HANDLE_VALUE) { \
+		sp_close(port); \
+		RETURN_FAIL(#ovl "CreateEvent() failed"); \
+	} \
+} while (0)
+
+	INIT_OVERLAPPED(read_ovl);
+	INIT_OVERLAPPED(write_ovl);
+	INIT_OVERLAPPED(wait_ovl);
+
+	/* Set event mask for RX and error events. */
+	if (SetCommMask(port->hdl, EV_RXCHAR | EV_ERR) == 0) {
+		sp_close(port);
+		RETURN_FAIL("SetCommMask() failed");
+	}
+
+	port->writing = FALSE;
+	port->wait_running = FALSE;
+
+	ret = restart_wait(port);
+
+	if (ret < 0) {
+		sp_close(port);
+		RETURN_CODEVAL(ret);
 	}
-	max_data_len = max_data_size / sizeof(TCHAR);
-	if (!(value = malloc((max_value_len + 1) * sizeof(TCHAR)))) {
-		ret = SP_ERR_MEM;
-		goto out_close;
+#else
+	int flags_local = O_NONBLOCK | O_NOCTTY;
+
+	/* Map 'flags' to the OS-specific settings. */
+	if ((flags & SP_MODE_READ_WRITE) == SP_MODE_READ_WRITE)
+		flags_local |= O_RDWR;
+	else if (flags & SP_MODE_READ)
+		flags_local |= O_RDONLY;
+	else if (flags & SP_MODE_WRITE)
+		flags_local |= O_WRONLY;
+
+	if ((port->fd = open(port->name, flags_local)) < 0)
+		RETURN_FAIL("open() failed");
+#endif
+
+	ret = get_config(port, &data, &config);
+
+	if (ret < 0) {
+		sp_close(port);
+		RETURN_CODEVAL(ret);
 	}
-	if (!(data = malloc((max_data_len + 1) * sizeof(TCHAR)))) {
-		ret = SP_ERR_MEM;
-		goto out_free_value;
+
+	/* Set sane port settings. */
+#ifdef _WIN32
+	data.dcb.fBinary = TRUE;
+	data.dcb.fDsrSensitivity = FALSE;
+	data.dcb.fErrorChar = FALSE;
+	data.dcb.fNull = FALSE;
+	data.dcb.fAbortOnError = FALSE;
+#else
+	/* Turn off all fancy termios tricks, give us a raw channel. */
+	data.term.c_iflag &= ~(IGNBRK | BRKINT | PARMRK | ISTRIP | INLCR | IGNCR | ICRNL | IMAXBEL);
+#ifdef IUCLC
+	data.term.c_iflag &= ~IUCLC;
+#endif
+	data.term.c_oflag &= ~(OPOST | ONLCR | OCRNL | ONOCR | ONLRET);
+#ifdef OLCUC
+	data.term.c_oflag &= ~OLCUC;
+#endif
+#ifdef NLDLY
+	data.term.c_oflag &= ~NLDLY;
+#endif
+#ifdef CRDLY
+	data.term.c_oflag &= ~CRDLY;
+#endif
+#ifdef TABDLY
+	data.term.c_oflag &= ~TABDLY;
+#endif
+#ifdef BSDLY
+	data.term.c_oflag &= ~BSDLY;
+#endif
+#ifdef VTDLY
+	data.term.c_oflag &= ~VTDLY;
+#endif
+#ifdef FFDLY
+	data.term.c_oflag &= ~FFDLY;
+#endif
+#ifdef OFILL
+	data.term.c_oflag &= ~OFILL;
+#endif
+	data.term.c_lflag &= ~(ISIG | ICANON | ECHO | IEXTEN);
+	data.term.c_cc[VMIN] = 0;
+	data.term.c_cc[VTIME] = 0;
+
+	/* Ignore modem status lines; enable receiver; leave control lines alone on close. */
+	data.term.c_cflag |= (CLOCAL | CREAD | HUPCL);
+#endif
+
+#ifdef _WIN32
+	if (ClearCommError(port->hdl, &errors, &status) == 0)
+		RETURN_FAIL("ClearCommError() failed");
+#endif
+
+	ret = set_config(port, &data, &config);
+
+	if (ret < 0) {
+		sp_close(port);
+		RETURN_CODEVAL(ret);
 	}
-	while (
-		value_len = max_value_len + 1,
-		data_size = max_data_size,
-		RegEnumValue(key, index, value, &value_len,
-			NULL, &type, (LPBYTE)data, &data_size) == ERROR_SUCCESS)
-	{
-		data_len = data_size / sizeof(TCHAR);
-		data[data_len] = '\0';
-#ifdef UNICODE
-		name_len = WideCharToMultiByte(CP_ACP, 0, data, -1, NULL, 0, NULL, NULL)
+
+	RETURN_OK();
+}
+
+SP_API enum sp_return sp_close(struct sp_port *port)
+{
+	TRACE("%p", port);
+
+	CHECK_OPEN_PORT();
+
+	DEBUG_FMT("Closing port %s", port->name);
+
+#ifdef _WIN32
+	/* Returns non-zero upon success, 0 upon failure. */
+	if (CloseHandle(port->hdl) == 0)
+		RETURN_FAIL("Port CloseHandle() failed");
+	port->hdl = INVALID_HANDLE_VALUE;
+
+	/* Close event handles for overlapped structures. */
+#define CLOSE_OVERLAPPED(ovl) do { \
+	if (port->ovl.hEvent != INVALID_HANDLE_VALUE && \
+		CloseHandle(port->ovl.hEvent) == 0) \
+		RETURN_FAIL(# ovl "event CloseHandle() failed"); \
+} while (0)
+	CLOSE_OVERLAPPED(read_ovl);
+	CLOSE_OVERLAPPED(write_ovl);
+	CLOSE_OVERLAPPED(wait_ovl);
+
 #else
-		name_len = data_len + 1;
+	/* Returns 0 upon success, -1 upon failure. */
+	if (close(port->fd) == -1)
+		RETURN_FAIL("close() failed");
+	port->fd = -1;
 #endif
-		if (!(name = malloc(name_len))) {
-			ret = SP_ERR_MEM;
-			goto out;
-		}
-#ifdef UNICODE
-		WideCharToMultiByte(CP_ACP, 0, data, -1, name, name_len, NULL, NULL);
+
+	RETURN_OK();
+}
+
+SP_API enum sp_return sp_flush(struct sp_port *port, enum sp_buffer buffers)
+{
+	TRACE("%p, 0x%x", port, buffers);
+
+	CHECK_OPEN_PORT();
+
+	if (buffers > SP_BUF_BOTH)
+		RETURN_ERROR(SP_ERR_ARG, "Invalid buffer selection");
+
+	const char *buffer_names[] = {"no", "input", "output", "both"};
+
+	DEBUG_FMT("Flushing %s buffers on port %s",
+		buffer_names[buffers], port->name);
+
+#ifdef _WIN32
+	DWORD flags = 0;
+	if (buffers & SP_BUF_INPUT)
+		flags |= PURGE_RXCLEAR;
+	if (buffers & SP_BUF_OUTPUT)
+		flags |= PURGE_TXCLEAR;
+
+	/* Returns non-zero upon success, 0 upon failure. */
+	if (PurgeComm(port->hdl, flags) == 0)
+		RETURN_FAIL("PurgeComm() failed");
+
+	if (buffers & SP_BUF_INPUT)
+		TRY(restart_wait(port));
 #else
-		strcpy(name, data);
+	int flags = 0;
+	if (buffers == SP_BUF_BOTH)
+		flags = TCIOFLUSH;
+	else if (buffers == SP_BUF_INPUT)
+		flags = TCIFLUSH;
+	else if (buffers == SP_BUF_OUTPUT)
+		flags = TCOFLUSH;
+
+	/* Returns 0 upon success, -1 upon failure. */
+	if (tcflush(port->fd, flags) < 0)
+		RETURN_FAIL("tcflush() failed");
 #endif
-		if (type == REG_SZ && !(list = list_append(list, name))) {
-			ret = SP_ERR_MEM;
-			goto out;
+	RETURN_OK();
+}
+
+SP_API enum sp_return sp_drain(struct sp_port *port)
+{
+	TRACE("%p", port);
+
+	CHECK_OPEN_PORT();
+
+	DEBUG_FMT("Draining port %s", port->name);
+
+#ifdef _WIN32
+	/* Returns non-zero upon success, 0 upon failure. */
+	if (FlushFileBuffers(port->hdl) == 0)
+		RETURN_FAIL("FlushFileBuffers() failed");
+	RETURN_OK();
+#else
+	int result;
+	while (1) {
+#ifdef __ANDROID__
+		int arg = 1;
+		result = ioctl(port->fd, TCSBRK, &arg);
+#else
+		result = tcdrain(port->fd);
+#endif
+		if (result < 0) {
+			if (errno == EINTR) {
+				DEBUG("tcdrain() was interrupted");
+				continue;
+			} else {
+				RETURN_FAIL("tcdrain() failed");
+			}
+		} else {
+			RETURN_OK();
 		}
-		index++;
 	}
-out:
-	free(data);
-out_free_value:
-	free(value);
-out_close:
-	RegCloseKey(key);
-out_done:
 #endif
-#ifdef __APPLE__
-	mach_port_t master;
-	CFMutableDictionaryRef classes;
-	io_iterator_t iter;
-	char *path;
-	io_object_t port;
-	CFTypeRef cf_path;
-	Boolean result;
-
-	if (IOMasterPort(MACH_PORT_NULL, &master) != KERN_SUCCESS) {
-		ret = SP_ERR_FAIL;
-		goto out_done;
+}
+
+SP_API enum sp_return sp_blocking_write(struct sp_port *port, const void *buf,
+                                        size_t count, unsigned int timeout)
+{
+	TRACE("%p, %p, %d, %d", port, buf, count, timeout);
+
+	CHECK_OPEN_PORT();
+
+	if (!buf)
+		RETURN_ERROR(SP_ERR_ARG, "Null buffer");
+
+	if (timeout)
+		DEBUG_FMT("Writing %d bytes to port %s, timeout %d ms",
+			count, port->name, timeout);
+	else
+		DEBUG_FMT("Writing %d bytes to port %s, no timeout",
+			count, port->name);
+
+	if (count == 0)
+		RETURN_INT(0);
+
+#ifdef _WIN32
+	DWORD bytes_written = 0;
+	BOOL result;
+
+	/* Wait for previous non-blocking write to complete, if any. */
+	if (port->writing) {
+		DEBUG("Waiting for previous write to complete");
+		result = GetOverlappedResult(port->hdl, &port->write_ovl, &bytes_written, TRUE);
+		port->writing = 0;
+		if (!result)
+			RETURN_FAIL("Previous write failed to complete");
+		DEBUG("Previous write completed");
 	}
 
-	if (!(classes = IOServiceMatching(kIOSerialBSDServiceValue))) {
-		ret = SP_ERR_FAIL;
-		goto out_done;
+	/* Set timeout. */
+	port->timeouts.WriteTotalTimeoutConstant = timeout;
+	if (SetCommTimeouts(port->hdl, &port->timeouts) == 0)
+		RETURN_FAIL("SetCommTimeouts() failed");
+
+	/* Start write. */
+	if (WriteFile(port->hdl, buf, count, NULL, &port->write_ovl) == 0) {
+		if (GetLastError() == ERROR_IO_PENDING) {
+			DEBUG("Waiting for write to complete");
+			GetOverlappedResult(port->hdl, &port->write_ovl, &bytes_written, TRUE);
+			DEBUG_FMT("Write completed, %d/%d bytes written", bytes_written, count);
+			RETURN_INT(bytes_written);
+		} else {
+			RETURN_FAIL("WriteFile() failed");
+		}
+	} else {
+		DEBUG("Write completed immediately");
+		RETURN_INT(count);
+	}
+#else
+	size_t bytes_written = 0;
+	unsigned char *ptr = (unsigned char *) buf;
+	struct timeval start, delta, now, end = {0, 0};
+	fd_set fds;
+	int result;
+
+	if (timeout) {
+		/* Get time at start of operation. */
+		gettimeofday(&start, NULL);
+		/* Define duration of timeout. */
+		delta.tv_sec = timeout / 1000;
+		delta.tv_usec = (timeout % 1000) * 1000;
+		/* Calculate time at which we should give up. */
+		timeradd(&start, &delta, &end);
 	}
 
-	CFDictionarySetValue(classes,
-			CFSTR(kIOSerialBSDTypeKey), CFSTR(kIOSerialBSDAllTypes));
+	/* Loop until we have written the requested number of bytes. */
+	while (bytes_written < count) {
+		/* Wait until space is available. */
+		FD_ZERO(&fds);
+		FD_SET(port->fd, &fds);
+		if (timeout) {
+			gettimeofday(&now, NULL);
+			if (timercmp(&now, &end, >)) {
+				DEBUG("Write timed out");
+				RETURN_INT(bytes_written);
+			}
+			timersub(&end, &now, &delta);
+		}
+		result = select(port->fd + 1, NULL, &fds, NULL, timeout ? &delta : NULL);
+		if (result < 0) {
+			if (errno == EINTR) {
+				DEBUG("select() call was interrupted, repeating");
+				continue;
+			} else {
+				RETURN_FAIL("select() failed");
+			}
+		} else if (result == 0) {
+			DEBUG("Write timed out");
+			RETURN_INT(bytes_written);
+		}
+
+		/* Do write. */
+		result = write(port->fd, ptr, count - bytes_written);
+
+		if (result < 0) {
+			if (errno == EAGAIN)
+				/* This shouldn't happen because we did a select() first, but handle anyway. */
+				continue;
+			else
+				/* This is an actual failure. */
+				RETURN_FAIL("write() failed");
+		}
 
-	if (IOServiceGetMatchingServices(master, classes, &iter) != KERN_SUCCESS) {
-		ret = SP_ERR_FAIL;
-		goto out_done;
+		bytes_written += result;
+		ptr += result;
 	}
 
-	if (!(path = malloc(PATH_MAX))) {
-		ret = SP_ERR_MEM;
-		goto out_release;
+	RETURN_INT(bytes_written);
+#endif
+}
+
+SP_API enum sp_return sp_nonblocking_write(struct sp_port *port,
+                                           const void *buf, size_t count)
+{
+	TRACE("%p, %p, %d", port, buf, count);
+
+	CHECK_OPEN_PORT();
+
+	if (!buf)
+		RETURN_ERROR(SP_ERR_ARG, "Null buffer");
+
+	DEBUG_FMT("Writing up to %d bytes to port %s", count, port->name);
+
+	if (count == 0)
+		RETURN_INT(0);
+
+#ifdef _WIN32
+	DWORD written = 0;
+	BYTE *ptr = (BYTE *) buf;
+
+	/* Check whether previous write is complete. */
+	if (port->writing) {
+		if (HasOverlappedIoCompleted(&port->write_ovl)) {
+			DEBUG("Previous write completed");
+			port->writing = 0;
+		} else {
+			DEBUG("Previous write not complete");
+			/* Can't take a new write until the previous one finishes. */
+			RETURN_INT(0);
+		}
 	}
 
-	while ((port = IOIteratorNext(iter))) {
-		cf_path = IORegistryEntryCreateCFProperty(port,
-				CFSTR(kIOCalloutDeviceKey), kCFAllocatorDefault, 0);
-		if (cf_path) {
-			result = CFStringGetCString(cf_path,
-					path, PATH_MAX, kCFStringEncodingASCII);
-			CFRelease(cf_path);
-			if (result && !(list = list_append(list, path))) {
-				ret = SP_ERR_MEM;
-				IOObjectRelease(port);
-				goto out;
+	/* Set timeout. */
+	port->timeouts.WriteTotalTimeoutConstant = 0;
+	if (SetCommTimeouts(port->hdl, &port->timeouts) == 0)
+		RETURN_FAIL("SetCommTimeouts() failed");
+
+	/*
+	 * Keep writing data until the OS has to actually start an async IO
+	 * for it. At that point we know the buffer is full.
+	 */
+	while (written < count) {
+		/* Copy first byte of user buffer. */
+		port->pending_byte = *ptr++;
+
+		/* Start asynchronous write. */
+		if (WriteFile(port->hdl, &port->pending_byte, 1, NULL, &port->write_ovl) == 0) {
+			if (GetLastError() == ERROR_IO_PENDING) {
+				if (HasOverlappedIoCompleted(&port->write_ovl)) {
+					DEBUG("Asynchronous write completed immediately");
+					port->writing = 0;
+					written++;
+					continue;
+				} else {
+					DEBUG("Asynchronous write running");
+					port->writing = 1;
+					RETURN_INT(++written);
+				}
+			} else {
+				/* Actual failure of some kind. */
+				RETURN_FAIL("WriteFile() failed");
 			}
+		} else {
+			DEBUG("Single byte written immediately");
+			written++;
 		}
-		IOObjectRelease(port);
 	}
-out:
-	free(path);
-out_release:
-	IOObjectRelease(iter);
-out_done:
+
+	DEBUG("All bytes written immediately");
+
+	RETURN_INT(written);
+#else
+	/* Returns the number of bytes written, or -1 upon failure. */
+	ssize_t written = write(port->fd, buf, count);
+
+	if (written < 0)
+		RETURN_FAIL("write() failed");
+	else
+		RETURN_INT(written);
 #endif
-#ifdef __linux__
-	struct udev *ud;
-	struct udev_enumerate *ud_enumerate;
-	struct udev_list_entry *ud_list;
-	struct udev_list_entry *ud_entry;
-	const char *path;
-	struct udev_device *ud_dev, *ud_parent;
-	const char *name;
-	const char *driver;
-	int fd, ioctl_result;
-	struct serial_struct serial_info;
-
-	ud = udev_new();
-	ud_enumerate = udev_enumerate_new(ud);
-	udev_enumerate_add_match_subsystem(ud_enumerate, "tty");
-	udev_enumerate_scan_devices(ud_enumerate);
-	ud_list = udev_enumerate_get_list_entry(ud_enumerate);
-	udev_list_entry_foreach(ud_entry, ud_list) {
-		path = udev_list_entry_get_name(ud_entry);
-		ud_dev = udev_device_new_from_syspath(ud, path);
-		/* If there is no parent device, this is a virtual tty. */
-		ud_parent = udev_device_get_parent(ud_dev);
-		if (ud_parent == NULL) {
-			udev_device_unref(ud_dev);
-			continue;
+}
+
+SP_API enum sp_return sp_blocking_read(struct sp_port *port, void *buf,
+                                       size_t count, unsigned int timeout)
+{
+	TRACE("%p, %p, %d, %d", port, buf, count, timeout);
+
+	CHECK_OPEN_PORT();
+
+	if (!buf)
+		RETURN_ERROR(SP_ERR_ARG, "Null buffer");
+
+	if (timeout)
+		DEBUG_FMT("Reading %d bytes from port %s, timeout %d ms",
+			count, port->name, timeout);
+	else
+		DEBUG_FMT("Reading %d bytes from port %s, no timeout",
+			count, port->name);
+
+	if (count == 0)
+		RETURN_INT(0);
+
+#ifdef _WIN32
+	DWORD bytes_read = 0;
+	DWORD bytes_remaining;
+	int ret;
+
+	/* Set timeout. */
+	port->timeouts.ReadIntervalTimeout = 0;
+	port->timeouts.ReadTotalTimeoutConstant = timeout;
+	if (SetCommTimeouts(port->hdl, &port->timeouts) == 0)
+		RETURN_FAIL("SetCommTimeouts() failed");
+
+	/* Start read. */
+	if (ReadFile(port->hdl, buf, count, NULL, &port->read_ovl) == 0) {
+		if (GetLastError() == ERROR_IO_PENDING) {
+			DEBUG("Waiting for read to complete");
+			GetOverlappedResult(port->hdl, &port->read_ovl, &bytes_read, TRUE);
+			DEBUG_FMT("Read completed, %d/%d bytes read", bytes_read, count);
+		} else {
+			RETURN_FAIL("ReadFile() failed");
+		}
+	} else {
+		DEBUG("Read completed immediately");
+		bytes_read = count;
+	}
+
+	ret = sp_input_waiting(port);
+
+	if (ret < 0)
+		RETURN_CODEVAL(ret);
+
+	bytes_remaining = ret;
+
+	/* Restart wait operation if buffer was emptied. */
+	if (bytes_read > 0 && bytes_remaining == 0)
+		TRY(restart_wait(port));
+
+	RETURN_INT(bytes_read);
+
+#else
+	size_t bytes_read = 0;
+	unsigned char *ptr = (unsigned char *) buf;
+	struct timeval start, delta, now, end = {0, 0};
+	fd_set fds;
+	int result;
+
+	if (timeout) {
+		/* Get time at start of operation. */
+		gettimeofday(&start, NULL);
+		/* Define duration of timeout. */
+		delta.tv_sec = timeout / 1000;
+		delta.tv_usec = (timeout % 1000) * 1000;
+		/* Calculate time at which we should give up. */
+		timeradd(&start, &delta, &end);
+	}
+
+	/* Loop until we have the requested number of bytes. */
+	while (bytes_read < count) {
+		/* Wait until data is available. */
+		FD_ZERO(&fds);
+		FD_SET(port->fd, &fds);
+		if (timeout) {
+			gettimeofday(&now, NULL);
+			if (timercmp(&now, &end, >))
+				/* Timeout has expired. */
+				RETURN_INT(bytes_read);
+			timersub(&end, &now, &delta);
 		}
-		name = udev_device_get_devnode(ud_dev);
-		/* The serial8250 driver has a hardcoded number of ports.
-		 * The only way to tell which actually exist on a given system
-		 * is to try to open them and make an ioctl call. */
-		driver = udev_device_get_driver(ud_parent);
-		if (driver && !strcmp(driver, "serial8250")) {
-			if ((fd = open(name, O_RDWR | O_NONBLOCK | O_NOCTTY)) < 0)
-				goto skip;
-			ioctl_result = ioctl(fd, TIOCGSERIAL, &serial_info);
-			close(fd);
-			if (ioctl_result != 0)
-				goto skip;
-			if (serial_info.type == PORT_UNKNOWN)
-				goto skip;
+		result = select(port->fd + 1, &fds, NULL, NULL, timeout ? &delta : NULL);
+		if (result < 0) {
+			if (errno == EINTR) {
+				DEBUG("select() call was interrupted, repeating");
+				continue;
+			} else {
+				RETURN_FAIL("select() failed");
+			}
+		} else if (result == 0) {
+			DEBUG("Read timed out");
+			RETURN_INT(bytes_read);
 		}
-		list = list_append(list, name);
-skip:
-		udev_device_unref(ud_dev);
-		if (!list) {
-			ret = SP_ERR_MEM;
-			goto out;
+
+		/* Do read. */
+		result = read(port->fd, ptr, count - bytes_read);
+
+		if (result < 0) {
+			if (errno == EAGAIN)
+				/* This shouldn't happen because we did a select() first, but handle anyway. */
+				continue;
+			else
+				/* This is an actual failure. */
+				RETURN_FAIL("read() failed");
 		}
+
+		bytes_read += result;
+		ptr += result;
 	}
-out:
-	udev_enumerate_unref(ud_enumerate);
-	udev_unref(ud);
+
+	RETURN_INT(bytes_read);
 #endif
+}
 
-	if (ret == SP_OK) {
-		*list_ptr = list;
-	} else {
-		if (list)
-			sp_free_port_list(list);
-		*list_ptr = NULL;
-	}
+SP_API enum sp_return sp_nonblocking_read(struct sp_port *port, void *buf,
+                                          size_t count)
+{
+	TRACE("%p, %p, %d", port, buf, count);
+
+	CHECK_OPEN_PORT();
+
+	if (!buf)
+		RETURN_ERROR(SP_ERR_ARG, "Null buffer");
+
+	DEBUG_FMT("Reading up to %d bytes from port %s", count, port->name);
+
+#ifdef _WIN32
+	DWORD bytes_read;
+	DWORD bytes_remaining;
+	int ret;
 
-	return ret;
+	/* Set timeout. */
+	port->timeouts.ReadIntervalTimeout = MAXDWORD;
+	port->timeouts.ReadTotalTimeoutConstant = 0;
+	if (SetCommTimeouts(port->hdl, &port->timeouts) == 0)
+		RETURN_FAIL("SetCommTimeouts() failed");
+
+	/* Do read. */
+	if (ReadFile(port->hdl, buf, count, NULL, &port->read_ovl) == 0)
+		RETURN_FAIL("ReadFile() failed");
+
+	/* Get number of bytes read. */
+	if (GetOverlappedResult(port->hdl, &port->read_ovl, &bytes_read, TRUE) == 0)
+		RETURN_FAIL("GetOverlappedResult() failed");
+
+	ret = sp_input_waiting(port);
+
+	if (ret < 0)
+		RETURN_CODEVAL(ret);
+
+	bytes_remaining = ret;
+
+	/* Restart wait operation if buffer was emptied. */
+	if (bytes_read > 0 && bytes_remaining == 0)
+		TRY(restart_wait(port));
+
+	RETURN_INT(bytes_read);
+#else
+	ssize_t bytes_read;
+
+	/* Returns the number of bytes read, or -1 upon failure. */
+	if ((bytes_read = read(port->fd, buf, count)) < 0) {
+		if (errno == EAGAIN)
+			/* No bytes available. */
+			bytes_read = 0;
+		else
+			/* This is an actual failure. */
+			RETURN_FAIL("read() failed");
+	}
+	RETURN_INT(bytes_read);
+#endif
 }
 
-void sp_free_port_list(struct sp_port **list)
+SP_API enum sp_return sp_input_waiting(struct sp_port *port)
 {
-	unsigned int i;
+	TRACE("%p", port);
 
-	for (i = 0; list[i]; i++)
-		sp_free_port(list[i]);
-	free(list);
+	CHECK_OPEN_PORT();
+
+	DEBUG_FMT("Checking input bytes waiting on port %s", port->name);
+
+#ifdef _WIN32
+	DWORD errors;
+	COMSTAT comstat;
+
+	if (ClearCommError(port->hdl, &errors, &comstat) == 0)
+		RETURN_FAIL("ClearCommError() failed");
+	RETURN_INT(comstat.cbInQue);
+#else
+	int bytes_waiting;
+	if (ioctl(port->fd, TIOCINQ, &bytes_waiting) < 0)
+		RETURN_FAIL("TIOCINQ ioctl failed");
+	RETURN_INT(bytes_waiting);
+#endif
 }
 
-static enum sp_return validate_port(struct sp_port *port)
+SP_API enum sp_return sp_output_waiting(struct sp_port *port)
 {
-	if (port == NULL)
-		return 0;
+	TRACE("%p", port);
+
+	CHECK_OPEN_PORT();
+
+	DEBUG_FMT("Checking output bytes waiting on port %s", port->name);
+
 #ifdef _WIN32
-	if (port->hdl == INVALID_HANDLE_VALUE)
-		return 0;
+	DWORD errors;
+	COMSTAT comstat;
+
+	if (ClearCommError(port->hdl, &errors, &comstat) == 0)
+		RETURN_FAIL("ClearCommError() failed");
+	RETURN_INT(comstat.cbOutQue);
 #else
-	if (port->fd < 0)
-		return 0;
+	int bytes_waiting;
+	if (ioctl(port->fd, TIOCOUTQ, &bytes_waiting) < 0)
+		RETURN_FAIL("TIOCOUTQ ioctl failed");
+	RETURN_INT(bytes_waiting);
 #endif
-	return 1;
 }
 
-#define CHECK_PORT() do { if (!validate_port(port)) return SP_ERR_ARG; } while (0)
+SP_API enum sp_return sp_new_event_set(struct sp_event_set **result_ptr)
+{
+	struct sp_event_set *result;
+
+	TRACE("%p", result_ptr);
+
+	if (!result_ptr)
+		RETURN_ERROR(SP_ERR_ARG, "Null result");
+
+	*result_ptr = NULL;
+
+	if (!(result = malloc(sizeof(struct sp_event_set))))
+		RETURN_ERROR(SP_ERR_MEM, "sp_event_set malloc() failed");
+
+	memset(result, 0, sizeof(struct sp_event_set));
+
+	*result_ptr = result;
+
+	RETURN_OK();
+}
+
+static enum sp_return add_handle(struct sp_event_set *event_set,
+		event_handle handle, enum sp_event mask)
+{
+	void *new_handles;
+	enum sp_event *new_masks;
+
+	TRACE("%p, %d, %d", event_set, handle, mask);
+
+	if (!(new_handles = realloc(event_set->handles,
+			sizeof(event_handle) * (event_set->count + 1))))
+		RETURN_ERROR(SP_ERR_MEM, "Handle array realloc() failed");
 
-enum sp_return sp_open(struct sp_port *port, enum sp_mode flags)
+	event_set->handles = new_handles;
+
+	if (!(new_masks = realloc(event_set->masks,
+			sizeof(enum sp_event) * (event_set->count + 1))))
+		RETURN_ERROR(SP_ERR_MEM, "Mask array realloc() failed");
+
+	event_set->masks = new_masks;
+
+	((event_handle *) event_set->handles)[event_set->count] = handle;
+	event_set->masks[event_set->count] = mask;
+
+	event_set->count++;
+
+	RETURN_OK();
+}
+
+SP_API enum sp_return sp_add_port_events(struct sp_event_set *event_set,
+	const struct sp_port *port, enum sp_event mask)
 {
+	TRACE("%p, %p, %d", event_set, port, mask);
+
+	if (!event_set)
+		RETURN_ERROR(SP_ERR_ARG, "Null event set");
+
 	if (!port)
-		return SP_ERR_ARG;
+		RETURN_ERROR(SP_ERR_ARG, "Null port");
+
+	if (mask > (SP_EVENT_RX_READY | SP_EVENT_TX_READY | SP_EVENT_ERROR))
+		RETURN_ERROR(SP_ERR_ARG, "Invalid event mask");
+
+	if (!mask)
+		RETURN_OK();
 
 #ifdef _WIN32
-	DWORD desired_access = 0, flags_and_attributes = 0;
-	char *escaped_port_name;
+	enum sp_event handle_mask;
+	if ((handle_mask = mask & SP_EVENT_TX_READY))
+		TRY(add_handle(event_set, port->write_ovl.hEvent, handle_mask));
+	if ((handle_mask = mask & (SP_EVENT_RX_READY | SP_EVENT_ERROR)))
+		TRY(add_handle(event_set, port->wait_ovl.hEvent, handle_mask));
+#else
+	TRY(add_handle(event_set, port->fd, mask));
+#endif
+
+	RETURN_OK();
+}
+
+SP_API void sp_free_event_set(struct sp_event_set *event_set)
+{
+	TRACE("%p", event_set);
+
+	if (!event_set) {
+		DEBUG("Null event set");
+		RETURN();
+	}
+
+	DEBUG("Freeing event set");
+
+	if (event_set->handles)
+		free(event_set->handles);
+	if (event_set->masks)
+		free(event_set->masks);
+
+	free(event_set);
+
+	RETURN();
+}
+
+SP_API enum sp_return sp_wait(struct sp_event_set *event_set,
+                              unsigned int timeout)
+{
+	TRACE("%p, %d", event_set, timeout);
+
+	if (!event_set)
+		RETURN_ERROR(SP_ERR_ARG, "Null event set");
+
+#ifdef _WIN32
+	if (WaitForMultipleObjects(event_set->count, event_set->handles, FALSE,
+			timeout ? timeout : INFINITE) == WAIT_FAILED)
+		RETURN_FAIL("WaitForMultipleObjects() failed");
+
+	RETURN_OK();
+#else
+	struct timeval start, delta, now, end = {0, 0};
+	int result, timeout_remaining;
+	struct pollfd *pollfds;
+	unsigned int i;
+
+	if (!(pollfds = malloc(sizeof(struct pollfd) * event_set->count)))
+		RETURN_ERROR(SP_ERR_MEM, "pollfds malloc() failed");
+
+	for (i = 0; i < event_set->count; i++) {
+		pollfds[i].fd = ((int *) event_set->handles)[i];
+		pollfds[i].events = 0;
+		pollfds[i].revents = 0;
+		if (event_set->masks[i] & SP_EVENT_RX_READY)
+			pollfds[i].events |= POLLIN;
+		if (event_set->masks[i] & SP_EVENT_TX_READY)
+			pollfds[i].events |= POLLOUT;
+		if (event_set->masks[i] & SP_EVENT_ERROR)
+			pollfds[i].events |= POLLERR;
+	}
+
+	if (timeout) {
+		/* Get time at start of operation. */
+		gettimeofday(&start, NULL);
+		/* Define duration of timeout. */
+		delta.tv_sec = timeout / 1000;
+		delta.tv_usec = (timeout % 1000) * 1000;
+		/* Calculate time at which we should give up. */
+		timeradd(&start, &delta, &end);
+	}
+
+	/* Loop until an event occurs. */
+	while (1) {
+		if (timeout) {
+			gettimeofday(&now, NULL);
+			if (timercmp(&now, &end, >)) {
+				DEBUG("Wait timed out");
+				break;
+			}
+			timersub(&end, &now, &delta);
+			timeout_remaining = delta.tv_sec * 1000 + delta.tv_usec / 1000;
+		}
+
+		result = poll(pollfds, event_set->count, timeout ? timeout_remaining : -1);
+
+		if (result < 0) {
+			if (errno == EINTR) {
+				DEBUG("poll() call was interrupted, repeating");
+				continue;
+			} else {
+				free(pollfds);
+				RETURN_FAIL("poll() failed");
+			}
+		} else if (result == 0) {
+			DEBUG("poll() timed out");
+			break;
+		} else {
+			DEBUG("poll() completed");
+			break;
+		}
+	}
+
+	free(pollfds);
+	RETURN_OK();
+#endif
+}
+
+#ifdef USE_TERMIOS_SPEED
+static enum sp_return get_baudrate(int fd, int *baudrate)
+{
+	void *data;
+
+	TRACE("%d, %p", fd, baudrate);
+
+	DEBUG("Getting baud rate");
 
-	/* Prefix port name with '\\.\' to work with ports above COM9. */
-	if (!(escaped_port_name = malloc(strlen(port->name + 5))))
-		return SP_ERR_MEM;
-	sprintf(escaped_port_name, "\\\\.\\%s", port->name);
+	if (!(data = malloc(get_termios_size())))
+		RETURN_ERROR(SP_ERR_MEM, "termios malloc failed");
 
-	/* Map 'flags' to the OS-specific settings. */
-	desired_access |= GENERIC_READ;
-	flags_and_attributes = FILE_ATTRIBUTE_NORMAL;
-	if (flags & SP_MODE_RDWR)
-		desired_access |= GENERIC_WRITE;
-	if (flags & SP_MODE_NONBLOCK)
-		flags_and_attributes |= FILE_FLAG_OVERLAPPED;
+	if (ioctl(fd, get_termios_get_ioctl(), data) < 0) {
+		free(data);
+		RETURN_FAIL("Getting termios failed");
+	}
 
-	port->hdl = CreateFile(escaped_port_name, desired_access, 0, 0,
-			 OPEN_EXISTING, flags_and_attributes, 0);
+	*baudrate = get_termios_speed(data);
 
-	free(escaped_port_name);
+	free(data);
 
-	if (port->hdl == INVALID_HANDLE_VALUE)
-		return SP_ERR_FAIL;
-#else
-	int flags_local = 0;
-	struct port_data data;
-	struct sp_port_config config;
-	int ret;
+	RETURN_OK();
+}
 
-	/* Map 'flags' to the OS-specific settings. */
-	if (flags & SP_MODE_RDWR)
-		flags_local |= O_RDWR;
-	if (flags & SP_MODE_RDONLY)
-		flags_local |= O_RDONLY;
-	if (flags & SP_MODE_NONBLOCK)
-		flags_local |= O_NONBLOCK;
+static enum sp_return set_baudrate(int fd, int baudrate)
+{
+	void *data;
 
-	if ((port->fd = open(port->name, flags_local)) < 0)
-		return SP_ERR_FAIL;
+	TRACE("%d, %d", fd, baudrate);
 
-	ret = get_config(port, &data, &config);
+	DEBUG("Getting baud rate");
 
-	if (ret < 0) {
-		sp_close(port);
-		return ret;
-	}
+	if (!(data = malloc(get_termios_size())))
+		RETURN_ERROR(SP_ERR_MEM, "termios malloc failed");
 
-	/* Turn off all serial port cooking. */
-	data.term.c_iflag &= ~(ISTRIP | INLCR | ICRNL);
-	data.term.c_oflag &= ~(ONLCR | OCRNL | ONOCR);
-#if !defined(__FreeBSD__) && !defined(__OpenBSD__) && !defined(__NetBSD__)
-	data.term.c_oflag &= ~OFILL;
-#endif
-	/* Disable canonical mode, and don't echo input characters. */
-	data.term.c_lflag &= ~(ICANON | ECHO);
+	if (ioctl(fd, get_termios_get_ioctl(), data) < 0) {
+		free(data);
+		RETURN_FAIL("Getting termios failed");
+	}
 
-	/* Ignore modem status lines; enable receiver */
-	data.term.c_cflag |= (CLOCAL | CREAD);
+	DEBUG("Setting baud rate");
 
-	ret = set_config(port, &data, &config);
+	set_termios_speed(data, baudrate);
 
-	if (ret < 0) {
-		sp_close(port);
-		return ret;
+	if (ioctl(fd, get_termios_set_ioctl(), data) < 0) {
+		free(data);
+		RETURN_FAIL("Setting termios failed");
 	}
-#endif
 
-	return SP_OK;
+	free(data);
+
+	RETURN_OK();
 }
+#endif /* USE_TERMIOS_SPEED */
 
-enum sp_return sp_close(struct sp_port *port)
+#ifdef USE_TERMIOX
+static enum sp_return get_flow(int fd, struct port_data *data)
 {
-	CHECK_PORT();
+	void *termx;
 
-#ifdef _WIN32
-	/* Returns non-zero upon success, 0 upon failure. */
-	if (CloseHandle(port->hdl) == 0)
-		return SP_ERR_FAIL;
-	port->hdl = INVALID_HANDLE_VALUE;
-#else
-	/* Returns 0 upon success, -1 upon failure. */
-	if (close(port->fd) == -1)
-		return SP_ERR_FAIL;
-	port->fd = -1;
-#endif
+	TRACE("%d, %p", fd, data);
 
-	return SP_OK;
-}
+	DEBUG("Getting advanced flow control");
 
-enum sp_return sp_flush(struct sp_port *port)
-{
-	CHECK_PORT();
+	if (!(termx = malloc(get_termiox_size())))
+		RETURN_ERROR(SP_ERR_MEM, "termiox malloc failed");
 
-#ifdef _WIN32
-	/* Returns non-zero upon success, 0 upon failure. */
-	if (PurgeComm(port->hdl, PURGE_RXCLEAR | PURGE_TXCLEAR) == 0)
-		return SP_ERR_FAIL;
-#else
-	/* Returns 0 upon success, -1 upon failure. */
-	if (tcflush(port->fd, TCIOFLUSH) < 0)
-		return SP_ERR_FAIL;
-#endif
-	return SP_OK;
+	if (ioctl(fd, TCGETX, termx) < 0) {
+		free(termx);
+		RETURN_FAIL("Getting termiox failed");
+	}
+
+	get_termiox_flow(termx, &data->rts_flow, &data->cts_flow,
+			&data->dtr_flow, &data->dsr_flow);
+
+	free(termx);
+
+	RETURN_OK();
 }
 
-enum sp_return sp_write(struct sp_port *port, const void *buf, size_t count)
+static enum sp_return set_flow(int fd, struct port_data *data)
 {
-	CHECK_PORT();
+	void *termx;
 
-	if (!buf)
-		return SP_ERR_ARG;
+	TRACE("%d, %p", fd, data);
 
-#ifdef _WIN32
-	DWORD written = 0;
+	DEBUG("Getting advanced flow control");
 
-	/* Returns non-zero upon success, 0 upon failure. */
-	if (WriteFile(port->hdl, buf, count, &written, NULL) == 0)
-		return SP_ERR_FAIL;
-	return written;
-#else
-	/* Returns the number of bytes written, or -1 upon failure. */
-	ssize_t written = write(port->fd, buf, count);
+	if (!(termx = malloc(get_termiox_size())))
+		RETURN_ERROR(SP_ERR_MEM, "termiox malloc failed");
 
-	if (written < 0)
-		return SP_ERR_FAIL;
-	else
-		return written;
-#endif
-}
+	if (ioctl(fd, TCGETX, termx) < 0) {
+		free(termx);
+		RETURN_FAIL("Getting termiox failed");
+	}
 
-enum sp_return sp_read(struct sp_port *port, void *buf, size_t count)
-{
-	CHECK_PORT();
+	DEBUG("Setting advanced flow control");
 
-	if (!buf)
-		return SP_ERR_ARG;
+	set_termiox_flow(termx, data->rts_flow, data->cts_flow,
+			data->dtr_flow, data->dsr_flow);
 
-#ifdef _WIN32
-	DWORD bytes_read = 0;
+	if (ioctl(fd, TCSETX, termx) < 0) {
+		free(termx);
+		RETURN_FAIL("Setting termiox failed");
+	}
 
-	/* Returns non-zero upon success, 0 upon failure. */
-	if (ReadFile(port->hdl, buf, count, &bytes_read, NULL) == 0)
-		return SP_ERR_FAIL;
-	return bytes_read;
-#else
-	ssize_t bytes_read;
+	free(termx);
 
-	/* Returns the number of bytes read, or -1 upon failure. */
-	if ((bytes_read = read(port->fd, buf, count)) < 0)
-		return SP_ERR_FAIL;
-	return bytes_read;
-#endif
+	RETURN_OK();
 }
+#endif /* USE_TERMIOX */
 
 static enum sp_return get_config(struct sp_port *port, struct port_data *data,
 	struct sp_port_config *config)
 {
 	unsigned int i;
 
+	TRACE("%p, %p, %p", port, data, config);
+
+	DEBUG_FMT("Getting configuration for port %s", port->name);
+
 #ifdef _WIN32
 	if (!GetCommState(port->hdl, &data->dcb))
-		return SP_ERR_FAIL;
+		RETURN_FAIL("GetCommState() failed");
 
 	for (i = 0; i < NUM_STD_BAUDRATES; i++) {
 		if (data->dcb.BaudRate == std_baudrates[i].index) {
@@ -585,11 +1458,17 @@ static enum sp_return get_config(struct sp_port *port, struct port_data *data,
 		case NOPARITY:
 			config->parity = SP_PARITY_NONE;
 			break;
+		case ODDPARITY:
+			config->parity = SP_PARITY_ODD;
+			break;
 		case EVENPARITY:
 			config->parity = SP_PARITY_EVEN;
 			break;
-		case ODDPARITY:
-			config->parity = SP_PARITY_ODD;
+		case MARKPARITY:
+			config->parity = SP_PARITY_MARK;
+			break;
+		case SPACEPARITY:
+			config->parity = SP_PARITY_SPACE;
 			break;
 		default:
 			config->parity = -1;
@@ -655,10 +1534,24 @@ static enum sp_return get_config(struct sp_port *port, struct port_data *data,
 #else // !_WIN32
 
 	if (tcgetattr(port->fd, &data->term) < 0)
-		return SP_ERR_FAIL;
+		RETURN_FAIL("tcgetattr() failed");
 
 	if (ioctl(port->fd, TIOCMGET, &data->controlbits) < 0)
-		return SP_ERR_FAIL;
+		RETURN_FAIL("TIOCMGET ioctl failed");
+
+#ifdef USE_TERMIOX
+	int ret = get_flow(port->fd, data);
+
+	if (ret == SP_ERR_FAIL && errno == EINVAL)
+		data->termiox_supported = 0;
+	else if (ret < 0)
+		RETURN_CODEVAL(ret);
+	else
+		data->termiox_supported = 1;
+#else
+	data->termiox_supported = 0;
+#endif
+
 	for (i = 0; i < NUM_STD_BAUDRATES; i++) {
 		if (cfgetispeed(&data->term) == std_baudrates[i].index) {
 			config->baudrate = std_baudrates[i].value;
@@ -669,6 +1562,8 @@ static enum sp_return get_config(struct sp_port *port, struct port_data *data,
 	if (i == NUM_STD_BAUDRATES) {
 #ifdef __APPLE__
 		config->baudrate = (int)data->term.c_ispeed;
+#elif defined(USE_TERMIOS_SPEED)
+		TRY(get_baudrate(port->fd, &config->baudrate));
 #else
 		config->baudrate = -1;
 #endif
@@ -695,6 +1590,10 @@ static enum sp_return get_config(struct sp_port *port, struct port_data *data,
 		config->parity = SP_PARITY_NONE;
 	else if (!(data->term.c_cflag & PARENB) || (data->term.c_iflag & IGNPAR))
 		config->parity = -1;
+#ifdef CMSPAR
+	else if (data->term.c_cflag & CMSPAR)
+		config->parity = (data->term.c_cflag & PARODD) ? SP_PARITY_MARK : SP_PARITY_SPACE;
+#endif
 	else
 		config->parity = (data->term.c_cflag & PARODD) ? SP_PARITY_ODD : SP_PARITY_EVEN;
 
@@ -704,12 +1603,22 @@ static enum sp_return get_config(struct sp_port *port, struct port_data *data,
 		config->rts = SP_RTS_FLOW_CONTROL;
 		config->cts = SP_CTS_FLOW_CONTROL;
 	} else {
-		config->rts = (data->controlbits & TIOCM_RTS) ? SP_RTS_ON : SP_RTS_OFF;
-		config->cts = SP_CTS_IGNORE;
+		if (data->termiox_supported && data->rts_flow)
+			config->rts = SP_RTS_FLOW_CONTROL;
+		else
+			config->rts = (data->controlbits & TIOCM_RTS) ? SP_RTS_ON : SP_RTS_OFF;
+
+		config->cts = (data->termiox_supported && data->cts_flow) ?
+			SP_CTS_FLOW_CONTROL : SP_CTS_IGNORE;
 	}
 
-	config->dtr = (data->controlbits & TIOCM_DTR) ? SP_DTR_ON : SP_DTR_OFF;
-	config->dsr = SP_DSR_IGNORE;
+	if (data->termiox_supported && data->dtr_flow)
+		config->dtr = SP_DTR_FLOW_CONTROL;
+	else
+		config->dtr = (data->controlbits & TIOCM_DTR) ? SP_DTR_ON : SP_DTR_OFF;
+
+	config->dsr = (data->termiox_supported && data->dsr_flow) ?
+		SP_DSR_FLOW_CONTROL : SP_DSR_IGNORE;
 
 	if (data->term.c_iflag & IXOFF) {
 		if (data->term.c_iflag & IXON)
@@ -724,10 +1633,10 @@ static enum sp_return get_config(struct sp_port *port, struct port_data *data,
 	}
 #endif
 
-	return SP_OK;
+	RETURN_OK();
 }
 
-static enum sp_return set_config(struct sp_port *port, struct port_data *data, 
+static enum sp_return set_config(struct sp_port *port, struct port_data *data,
 	const struct sp_port_config *config)
 {
 	unsigned int i;
@@ -736,6 +1645,13 @@ static enum sp_return set_config(struct sp_port *port, struct port_data *data,
 
 	baud_nonstd = B0;
 #endif
+#ifdef USE_TERMIOS_SPEED
+	int baud_nonstd = 0;
+#endif
+
+	TRACE("%p, %p, %p", port, data, config);
+
+	DEBUG_FMT("Setting configuration for port %s", port->name);
 
 #ifdef _WIN32
 	if (config->baudrate >= 0) {
@@ -755,18 +1671,23 @@ static enum sp_return set_config(struct sp_port *port, struct port_data *data,
 
 	if (config->parity >= 0) {
 		switch (config->parity) {
-		/* Note: There's also SPACEPARITY, MARKPARITY (unneeded so far). */
 		case SP_PARITY_NONE:
 			data->dcb.Parity = NOPARITY;
 			break;
+		case SP_PARITY_ODD:
+			data->dcb.Parity = ODDPARITY;
+			break;
 		case SP_PARITY_EVEN:
 			data->dcb.Parity = EVENPARITY;
 			break;
-		case SP_PARITY_ODD:
-			data->dcb.Parity = ODDPARITY;
+		case SP_PARITY_MARK:
+			data->dcb.Parity = MARKPARITY;
+			break;
+		case SP_PARITY_SPACE:
+			data->dcb.Parity = SPACEPARITY;
 			break;
 		default:
-			return SP_ERR_ARG;
+			RETURN_ERROR(SP_ERR_ARG, "Invalid parity setting");
 		}
 	}
 
@@ -780,7 +1701,7 @@ static enum sp_return set_config(struct sp_port *port, struct port_data *data,
 			data->dcb.StopBits = TWOSTOPBITS;
 			break;
 		default:
-			return SP_ERR_ARG;
+			RETURN_ERROR(SP_ERR_ARG, "Invalid stop bit setting");
 		}
 	}
 
@@ -796,7 +1717,7 @@ static enum sp_return set_config(struct sp_port *port, struct port_data *data,
 			data->dcb.fRtsControl = RTS_CONTROL_HANDSHAKE;
 			break;
 		default:
-			return SP_ERR_ARG;
+			RETURN_ERROR(SP_ERR_ARG, "Invalid RTS setting");
 		}
 	}
 
@@ -809,7 +1730,7 @@ static enum sp_return set_config(struct sp_port *port, struct port_data *data,
 			data->dcb.fOutxCtsFlow = TRUE;
 			break;
 		default:
-			return SP_ERR_ARG;
+			RETURN_ERROR(SP_ERR_ARG, "Invalid CTS setting");
 		}
 	}
 
@@ -825,7 +1746,7 @@ static enum sp_return set_config(struct sp_port *port, struct port_data *data,
 			data->dcb.fDtrControl = DTR_CONTROL_HANDSHAKE;
 			break;
 		default:
-			return SP_ERR_ARG;
+			RETURN_ERROR(SP_ERR_ARG, "Invalid DTR setting");
 		}
 	}
 
@@ -838,7 +1759,7 @@ static enum sp_return set_config(struct sp_port *port, struct port_data *data,
 			data->dcb.fOutxDsrFlow = TRUE;
 			break;
 		default:
-			return SP_ERR_ARG;
+			RETURN_ERROR(SP_ERR_ARG, "Invalid DSR setting");
 		}
 	}
 
@@ -861,23 +1782,25 @@ static enum sp_return set_config(struct sp_port *port, struct port_data *data,
 			data->dcb.fOutX = TRUE;
 			break;
 		default:
-			return SP_ERR_ARG;
+			RETURN_ERROR(SP_ERR_ARG, "Invalid XON/XOFF setting");
 		}
 	}
 
 	if (!SetCommState(port->hdl, &data->dcb))
-		return SP_ERR_FAIL;
+		RETURN_FAIL("SetCommState() failed");
 
 #else /* !_WIN32 */
 
+	int controlbits;
+
 	if (config->baudrate >= 0) {
 		for (i = 0; i < NUM_STD_BAUDRATES; i++) {
 			if (config->baudrate == std_baudrates[i].value) {
 				if (cfsetospeed(&data->term, std_baudrates[i].index) < 0)
-					return SP_ERR_FAIL;
+					RETURN_FAIL("cfsetospeed() failed");
 
 				if (cfsetispeed(&data->term, std_baudrates[i].index) < 0)
-					return SP_ERR_FAIL;
+					RETURN_FAIL("cfsetispeed() failed");
 				break;
 			}
 		}
@@ -885,12 +1808,14 @@ static enum sp_return set_config(struct sp_port *port, struct port_data *data,
 		/* Non-standard baud rate */
 		if (i == NUM_STD_BAUDRATES) {
 #ifdef __APPLE__
-			/* Set "dummy" baud rate */
+			/* Set "dummy" baud rate. */
 			if (cfsetspeed(&data->term, B9600) < 0)
-				return SP_ERR_FAIL;
+				RETURN_FAIL("cfsetspeed() failed");
 			baud_nonstd = config->baudrate;
+#elif defined(USE_TERMIOS_SPEED)
+			baud_nonstd = 1;
 #else
-			return SP_ERR_ARG;
+			RETURN_ERROR(SP_ERR_SUPP, "Non-standard baudrate not supported");
 #endif
 		}
 	}
@@ -911,13 +1836,16 @@ static enum sp_return set_config(struct sp_port *port, struct port_data *data,
 			data->term.c_cflag |= CS5;
 			break;
 		default:
-			return SP_ERR_ARG;
+			RETURN_ERROR(SP_ERR_ARG, "Invalid data bits setting");
 		}
 	}
 
 	if (config->parity >= 0) {
 		data->term.c_iflag &= ~IGNPAR;
 		data->term.c_cflag &= ~(PARENB | PARODD);
+#ifdef CMSPAR
+		data->term.c_cflag &= ~CMSPAR;
+#endif
 		switch (config->parity) {
 		case SP_PARITY_NONE:
 			data->term.c_iflag |= IGNPAR;
@@ -928,8 +1856,22 @@ static enum sp_return set_config(struct sp_port *port, struct port_data *data,
 		case SP_PARITY_ODD:
 			data->term.c_cflag |= PARENB | PARODD;
 			break;
+#ifdef CMSPAR
+		case SP_PARITY_MARK:
+			data->term.c_cflag |= PARENB | PARODD;
+			data->term.c_cflag |= CMSPAR;
+			break;
+		case SP_PARITY_SPACE:
+			data->term.c_cflag |= PARENB;
+			data->term.c_cflag |= CMSPAR;
+			break;
+#else
+		case SP_PARITY_MARK:
+		case SP_PARITY_SPACE:
+			RETURN_ERROR(SP_ERR_SUPP, "Mark/space parity not supported");
+#endif
 		default:
-			return SP_ERR_ARG;
+			RETURN_ERROR(SP_ERR_ARG, "Invalid parity setting");
 		}
 	}
 
@@ -943,52 +1885,94 @@ static enum sp_return set_config(struct sp_port *port, struct port_data *data,
 			data->term.c_cflag |= CSTOPB;
 			break;
 		default:
-			return SP_ERR_ARG;
+			RETURN_ERROR(SP_ERR_ARG, "Invalid stop bits setting");
 		}
 	}
 
 	if (config->rts >= 0 || config->cts >= 0) {
-		/* Asymmetric use of RTS/CTS not supported yet. */
-
-		if (data->term.c_iflag & CRTSCTS) {
-			/* Flow control can only be disabled for both RTS & CTS together. */
-			if (config->rts >= 0 && config->rts != SP_RTS_FLOW_CONTROL) {
-				if (config->cts != SP_CTS_IGNORE)
-					return SP_ERR_ARG;
-			}
-			if (config->cts >= 0 && config->cts != SP_CTS_FLOW_CONTROL) {
-				if (config->rts <= 0 || config->rts == SP_RTS_FLOW_CONTROL)
-					return SP_ERR_ARG;
+		if (data->termiox_supported) {
+			data->rts_flow = data->cts_flow = 0;
+			switch (config->rts) {
+			case SP_RTS_OFF:
+			case SP_RTS_ON:
+				controlbits = TIOCM_RTS;
+				if (ioctl(port->fd, config->rts == SP_RTS_ON ? TIOCMBIS : TIOCMBIC, &controlbits) < 0)
+					RETURN_FAIL("Setting RTS signal level failed");
+				break;
+			case SP_RTS_FLOW_CONTROL:
+				data->rts_flow = 1;
+				break;
+			default:
+				break;
 			}
-		} else {
-			/* Flow control can only be enabled for both RTS & CTS together. */
-			if (((config->rts == SP_RTS_FLOW_CONTROL) && (config->cts != SP_CTS_FLOW_CONTROL)) ||
-				((config->cts == SP_CTS_FLOW_CONTROL) && (config->rts != SP_RTS_FLOW_CONTROL)))
-				return SP_ERR_ARG;
-		}
+			if (config->cts == SP_CTS_FLOW_CONTROL)
+				data->cts_flow = 1;
 
-		if (config->rts >= 0) {
-			if (config->rts == SP_RTS_FLOW_CONTROL) {
+			if (data->rts_flow && data->cts_flow)
 				data->term.c_iflag |= CRTSCTS;
+			else
+				data->term.c_iflag &= ~CRTSCTS;
+		} else {
+			/* Asymmetric use of RTS/CTS not supported. */
+			if (data->term.c_iflag & CRTSCTS) {
+				/* Flow control can only be disabled for both RTS & CTS together. */
+				if (config->rts >= 0 && config->rts != SP_RTS_FLOW_CONTROL) {
+					if (config->cts != SP_CTS_IGNORE)
+						RETURN_ERROR(SP_ERR_SUPP, "RTS & CTS flow control must be disabled together");
+				}
+				if (config->cts >= 0 && config->cts != SP_CTS_FLOW_CONTROL) {
+					if (config->rts <= 0 || config->rts == SP_RTS_FLOW_CONTROL)
+						RETURN_ERROR(SP_ERR_SUPP, "RTS & CTS flow control must be disabled together");
+				}
 			} else {
-				int controlbits = TIOCM_RTS;
-				if (ioctl(port->fd, config->rts == SP_RTS_ON ? TIOCMBIS : TIOCMBIC,
-						&controlbits) < 0)
-					return SP_ERR_FAIL;
+				/* Flow control can only be enabled for both RTS & CTS together. */
+				if (((config->rts == SP_RTS_FLOW_CONTROL) && (config->cts != SP_CTS_FLOW_CONTROL)) ||
+					((config->cts == SP_CTS_FLOW_CONTROL) && (config->rts != SP_RTS_FLOW_CONTROL)))
+					RETURN_ERROR(SP_ERR_SUPP, "RTS & CTS flow control must be enabled together");
+			}
+
+			if (config->rts >= 0) {
+				if (config->rts == SP_RTS_FLOW_CONTROL) {
+					data->term.c_iflag |= CRTSCTS;
+				} else {
+					controlbits = TIOCM_RTS;
+					if (ioctl(port->fd, config->rts == SP_RTS_ON ? TIOCMBIS : TIOCMBIC,
+							&controlbits) < 0)
+						RETURN_FAIL("Setting RTS signal level failed");
+				}
 			}
 		}
 	}
 
 	if (config->dtr >= 0 || config->dsr >= 0) {
-		/* DTR/DSR flow control not supported yet. */
-		if (config->dtr == SP_DTR_FLOW_CONTROL || config->dsr == SP_DSR_FLOW_CONTROL)
-			return SP_ERR_ARG;
-
-		if (config->dtr >= 0) {
-			int controlbits = TIOCM_DTR;
-			if (ioctl(port->fd, config->dtr == SP_DTR_ON ? TIOCMBIS : TIOCMBIC,
-					&controlbits) < 0)
-				return SP_ERR_FAIL;
+		if (data->termiox_supported) {
+			data->dtr_flow = data->dsr_flow = 0;
+			switch (config->dtr) {
+			case SP_DTR_OFF:
+			case SP_DTR_ON:
+				controlbits = TIOCM_DTR;
+				if (ioctl(port->fd, config->dtr == SP_DTR_ON ? TIOCMBIS : TIOCMBIC, &controlbits) < 0)
+					RETURN_FAIL("Setting DTR signal level failed");
+				break;
+			case SP_DTR_FLOW_CONTROL:
+				data->dtr_flow = 1;
+				break;
+			default:
+				break;
+			}
+			if (config->dsr == SP_DSR_FLOW_CONTROL)
+				data->dsr_flow = 1;
+		} else {
+			/* DTR/DSR flow control not supported. */
+			if (config->dtr == SP_DTR_FLOW_CONTROL || config->dsr == SP_DSR_FLOW_CONTROL)
+				RETURN_ERROR(SP_ERR_SUPP, "DTR/DSR flow control not supported");
+
+			if (config->dtr >= 0) {
+				controlbits = TIOCM_DTR;
+				if (ioctl(port->fd, config->dtr == SP_DTR_ON ? TIOCMBIS : TIOCMBIC,
+						&controlbits) < 0)
+					RETURN_FAIL("Setting DTR signal level failed");
+			}
 		}
 	}
 
@@ -1007,115 +1991,295 @@ static enum sp_return set_config(struct sp_port *port, struct port_data *data,
 			data->term.c_iflag |= IXON | IXOFF | IXANY;
 			break;
 		default:
-			return SP_ERR_ARG;
+			RETURN_ERROR(SP_ERR_ARG, "Invalid XON/XOFF setting");
 		}
 	}
 
-	if (tcsetattr(port->fd, TCSADRAIN, &data->term) < 0)
-		return SP_ERR_FAIL;
+	if (tcsetattr(port->fd, TCSANOW, &data->term) < 0)
+		RETURN_FAIL("tcsetattr() failed");
 
 #ifdef __APPLE__
 	if (baud_nonstd != B0) {
 		if (ioctl(port->fd, IOSSIOSPEED, &baud_nonstd) == -1)
-			return SP_ERR_FAIL;
-		/* Set baud rates in data->term to correct, but incompatible
-		 * with tcsetattr() value, same as delivered by tcgetattr(). */
+			RETURN_FAIL("IOSSIOSPEED ioctl failed");
+		/*
+		 * Set baud rates in data->term to correct, but incompatible
+		 * with tcsetattr() value, same as delivered by tcgetattr().
+		 */
 		if (cfsetspeed(&data->term, baud_nonstd) < 0)
-			return SP_ERR_FAIL;
+			RETURN_FAIL("cfsetspeed() failed");
 	}
-#endif /* __APPLE__ */
+#elif defined(__linux__)
+#ifdef USE_TERMIOS_SPEED
+	if (baud_nonstd)
+		TRY(set_baudrate(port->fd, config->baudrate));
+#endif
+#ifdef USE_TERMIOX
+	if (data->termiox_supported)
+		TRY(set_flow(port->fd, data));
+#endif
+#endif
 
 #endif /* !_WIN32 */
 
-	return SP_OK;
+	RETURN_OK();
+}
+
+SP_API enum sp_return sp_new_config(struct sp_port_config **config_ptr)
+{
+	struct sp_port_config *config;
+
+	TRACE("%p", config_ptr);
+
+	if (!config_ptr)
+		RETURN_ERROR(SP_ERR_ARG, "Null result pointer");
+
+	*config_ptr = NULL;
+
+	if (!(config = malloc(sizeof(struct sp_port_config))))
+		RETURN_ERROR(SP_ERR_MEM, "Config malloc failed");
+
+	config->baudrate = -1;
+	config->bits = -1;
+	config->parity = -1;
+	config->stopbits = -1;
+	config->rts = -1;
+	config->cts = -1;
+	config->dtr = -1;
+	config->dsr = -1;
+
+	*config_ptr = config;
+
+	RETURN_OK();
+}
+
+SP_API void sp_free_config(struct sp_port_config *config)
+{
+	TRACE("%p", config);
+
+	if (!config)
+		DEBUG("Null config");
+	else
+		free(config);
+
+	RETURN();
 }
 
-#define TRY(x) do { int ret = x; if (ret != SP_OK) return ret; } while (0)
+SP_API enum sp_return sp_get_config(struct sp_port *port,
+                                    struct sp_port_config *config)
+{
+	struct port_data data;
+
+	TRACE("%p, %p", port, config);
+
+	CHECK_OPEN_PORT();
+
+	if (!config)
+		RETURN_ERROR(SP_ERR_ARG, "Null config");
+
+	TRY(get_config(port, &data, config));
+
+	RETURN_OK();
+}
 
-enum sp_return sp_set_config(struct sp_port *port, const struct sp_port_config *config)
+SP_API enum sp_return sp_set_config(struct sp_port *port,
+                                    const struct sp_port_config *config)
 {
 	struct port_data data;
 	struct sp_port_config prev_config;
 
-	CHECK_PORT();
+	TRACE("%p, %p", port, config);
+
+	CHECK_OPEN_PORT();
 
 	if (!config)
-		return SP_ERR_ARG;
+		RETURN_ERROR(SP_ERR_ARG, "Null config");
 
 	TRY(get_config(port, &data, &prev_config));
 	TRY(set_config(port, &data, config));
 
-	return SP_OK;
+	RETURN_OK();
 }
 
-#define CREATE_SETTER(x, type) int sp_set_##x(struct sp_port *port, type x) { \
+#define CREATE_ACCESSORS(x, type) \
+SP_API enum sp_return sp_set_##x(struct sp_port *port, type x) { \
 	struct port_data data; \
 	struct sp_port_config config; \
-	CHECK_PORT(); \
+	TRACE("%p, %d", port, x); \
+	CHECK_OPEN_PORT(); \
 	TRY(get_config(port, &data, &config)); \
 	config.x = x; \
 	TRY(set_config(port, &data, &config)); \
-	return SP_OK; \
+	RETURN_OK(); \
+} \
+SP_API enum sp_return sp_get_config_##x(const struct sp_port_config *config, \
+                                        type *x) { \
+	TRACE("%p, %p", config, x); \
+	if (!config) \
+		RETURN_ERROR(SP_ERR_ARG, "Null config"); \
+	*x = config->x; \
+	RETURN_OK(); \
+} \
+SP_API enum sp_return sp_set_config_##x(struct sp_port_config *config, \
+                                        type x) { \
+	TRACE("%p, %d", config, x); \
+	if (!config) \
+		RETURN_ERROR(SP_ERR_ARG, "Null config"); \
+	config->x = x; \
+	RETURN_OK(); \
 }
 
-CREATE_SETTER(baudrate, int)
-CREATE_SETTER(bits, int)
-CREATE_SETTER(parity, enum sp_parity)
-CREATE_SETTER(stopbits, int)
-CREATE_SETTER(rts, enum sp_rts)
-CREATE_SETTER(cts, enum sp_cts)
-CREATE_SETTER(dtr, enum sp_dtr)
-CREATE_SETTER(dsr, enum sp_dsr)
-CREATE_SETTER(xon_xoff, enum sp_xonxoff)
-
-enum sp_return sp_set_flowcontrol(struct sp_port *port, enum sp_flowcontrol flowcontrol)
+CREATE_ACCESSORS(baudrate, int)
+CREATE_ACCESSORS(bits, int)
+CREATE_ACCESSORS(parity, enum sp_parity)
+CREATE_ACCESSORS(stopbits, int)
+CREATE_ACCESSORS(rts, enum sp_rts)
+CREATE_ACCESSORS(cts, enum sp_cts)
+CREATE_ACCESSORS(dtr, enum sp_dtr)
+CREATE_ACCESSORS(dsr, enum sp_dsr)
+CREATE_ACCESSORS(xon_xoff, enum sp_xonxoff)
+
+SP_API enum sp_return sp_set_config_flowcontrol(struct sp_port_config *config,
+                                                enum sp_flowcontrol flowcontrol)
 {
-	struct port_data data;
-	struct sp_port_config config;
-
-	CHECK_PORT();
+	if (!config)
+		RETURN_ERROR(SP_ERR_ARG, "Null configuration");
 
-	TRY(get_config(port, &data, &config));
+	if (flowcontrol > SP_FLOWCONTROL_DTRDSR)
+		RETURN_ERROR(SP_ERR_ARG, "Invalid flow control setting");
 
 	if (flowcontrol == SP_FLOWCONTROL_XONXOFF)
-		config.xon_xoff = SP_XONXOFF_INOUT;
+		config->xon_xoff = SP_XONXOFF_INOUT;
 	else
-		config.xon_xoff = SP_XONXOFF_DISABLED;
+		config->xon_xoff = SP_XONXOFF_DISABLED;
 
 	if (flowcontrol == SP_FLOWCONTROL_RTSCTS) {
-		config.rts = SP_RTS_FLOW_CONTROL;
-		config.cts = SP_CTS_FLOW_CONTROL;
+		config->rts = SP_RTS_FLOW_CONTROL;
+		config->cts = SP_CTS_FLOW_CONTROL;
 	} else {
-		if (config.rts == SP_RTS_FLOW_CONTROL)
-			config.rts = SP_RTS_ON;
-		config.cts = SP_CTS_IGNORE;
+		if (config->rts == SP_RTS_FLOW_CONTROL)
+			config->rts = SP_RTS_ON;
+		config->cts = SP_CTS_IGNORE;
 	}
 
 	if (flowcontrol == SP_FLOWCONTROL_DTRDSR) {
-		config.dtr = SP_DTR_FLOW_CONTROL;
-		config.dsr = SP_DSR_FLOW_CONTROL;
+		config->dtr = SP_DTR_FLOW_CONTROL;
+		config->dsr = SP_DSR_FLOW_CONTROL;
 	} else {
-		if (config.dtr == SP_DTR_FLOW_CONTROL)
-			config.dtr = SP_DTR_ON;
-		config.dsr = SP_DSR_IGNORE;
+		if (config->dtr == SP_DTR_FLOW_CONTROL)
+			config->dtr = SP_DTR_ON;
+		config->dsr = SP_DSR_IGNORE;
 	}
 
+	RETURN_OK();
+}
+
+SP_API enum sp_return sp_set_flowcontrol(struct sp_port *port,
+                                         enum sp_flowcontrol flowcontrol)
+{
+	struct port_data data;
+	struct sp_port_config config;
+
+	TRACE("%p, %d", port, flowcontrol);
+
+	CHECK_OPEN_PORT();
+
+	TRY(get_config(port, &data, &config));
+
+	TRY(sp_set_config_flowcontrol(&config, flowcontrol));
+
 	TRY(set_config(port, &data, &config));
 
-	return SP_OK;
+	RETURN_OK();
+}
+
+SP_API enum sp_return sp_get_signals(struct sp_port *port,
+                                     enum sp_signal *signals)
+{
+	TRACE("%p, %p", port, signals);
+
+	CHECK_OPEN_PORT();
+
+	if (!signals)
+		RETURN_ERROR(SP_ERR_ARG, "Null result pointer");
+
+	DEBUG_FMT("Getting control signals for port %s", port->name);
+
+	*signals = 0;
+#ifdef _WIN32
+	DWORD bits;
+	if (GetCommModemStatus(port->hdl, &bits) == 0)
+		RETURN_FAIL("GetCommModemStatus() failed");
+	if (bits & MS_CTS_ON)
+		*signals |= SP_SIG_CTS;
+	if (bits & MS_DSR_ON)
+		*signals |= SP_SIG_DSR;
+	if (bits & MS_RLSD_ON)
+		*signals |= SP_SIG_DCD;
+	if (bits & MS_RING_ON)
+		*signals |= SP_SIG_RI;
+#else
+	int bits;
+	if (ioctl(port->fd, TIOCMGET, &bits) < 0)
+		RETURN_FAIL("TIOCMGET ioctl failed");
+	if (bits & TIOCM_CTS)
+		*signals |= SP_SIG_CTS;
+	if (bits & TIOCM_DSR)
+		*signals |= SP_SIG_DSR;
+	if (bits & TIOCM_CAR)
+		*signals |= SP_SIG_DCD;
+	if (bits & TIOCM_RNG)
+		*signals |= SP_SIG_RI;
+#endif
+	RETURN_OK();
+}
+
+SP_API enum sp_return sp_start_break(struct sp_port *port)
+{
+	TRACE("%p", port);
+
+	CHECK_OPEN_PORT();
+#ifdef _WIN32
+	if (SetCommBreak(port->hdl) == 0)
+		RETURN_FAIL("SetCommBreak() failed");
+#else
+	if (ioctl(port->fd, TIOCSBRK, 1) < 0)
+		RETURN_FAIL("TIOCSBRK ioctl failed");
+#endif
+
+	RETURN_OK();
+}
+
+SP_API enum sp_return sp_end_break(struct sp_port *port)
+{
+	TRACE("%p", port);
+
+	CHECK_OPEN_PORT();
+#ifdef _WIN32
+	if (ClearCommBreak(port->hdl) == 0)
+		RETURN_FAIL("ClearCommBreak() failed");
+#else
+	if (ioctl(port->fd, TIOCCBRK, 1) < 0)
+		RETURN_FAIL("TIOCCBRK ioctl failed");
+#endif
+
+	RETURN_OK();
 }
 
-int sp_last_error_code(void)
+SP_API int sp_last_error_code(void)
 {
+	TRACE_VOID();
 #ifdef _WIN32
-	return GetLastError();
+	RETURN_INT(GetLastError());
 #else
-	return errno;
+	RETURN_INT(errno);
 #endif
 }
 
-char *sp_last_error_message(void)
+SP_API char *sp_last_error_message(void)
 {
+	TRACE_VOID();
+
 #ifdef _WIN32
 	LPVOID message;
 	DWORD error = GetLastError();
@@ -1130,17 +2294,83 @@ char *sp_last_error_message(void)
 		(LPTSTR) &message,
 		0, NULL );
 
-	return message;
+	RETURN_STRING(message);
 #else
-	return strerror(errno);
+	RETURN_STRING(strerror(errno));
 #endif
 }
 
-void sp_free_error_message(char *message)
+SP_API void sp_free_error_message(char *message)
 {
+	TRACE("%s", message);
+
 #ifdef _WIN32
 	LocalFree(message);
 #else
 	(void)message;
 #endif
+
+	RETURN();
+}
+
+SP_API void sp_set_debug_handler(void (*handler)(const char *format, ...))
+{
+	TRACE("%p", handler);
+
+	sp_debug_handler = handler;
+
+	RETURN();
+}
+
+SP_API void sp_default_debug_handler(const char *format, ...)
+{
+	va_list args;
+	va_start(args, format);
+	if (getenv("LIBSERIALPORT_DEBUG")) {
+		fputs("sp: ", stderr);
+		vfprintf(stderr, format, args);
+	}
+	va_end(args);
+}
+
+SP_API int sp_get_major_package_version(void)
+{
+	return SP_PACKAGE_VERSION_MAJOR;
+}
+
+SP_API int sp_get_minor_package_version(void)
+{
+	return SP_PACKAGE_VERSION_MINOR;
+}
+
+SP_API int sp_get_micro_package_version(void)
+{
+	return SP_PACKAGE_VERSION_MICRO;
 }
+
+SP_API const char *sp_get_package_version_string(void)
+{
+	return SP_PACKAGE_VERSION_STRING;
+}
+
+SP_API int sp_get_current_lib_version(void)
+{
+	return SP_LIB_VERSION_CURRENT;
+}
+
+SP_API int sp_get_revision_lib_version(void)
+{
+	return SP_LIB_VERSION_REVISION;
+}
+
+SP_API int sp_get_age_lib_version(void)
+{
+	return SP_LIB_VERSION_AGE;
+}
+
+SP_API const char *sp_get_lib_version_string(void)
+{
+	return SP_LIB_VERSION_STRING;
+}
+
+/** @} */