X-Git-Url: http://sigrok.org/gitweb/?a=blobdiff_plain;f=serialport.c;h=074534edb8a898c280109a25b3da9ae537e1820e;hb=f14809393ace8e5f9a664975f34b701d1e35d2fa;hp=9ebc2da7f226324fa83ef0363620734a203b35eb;hpb=a93fb468885de8775f1d200625dac114d3050b1d;p=libserialport.git

diff --git a/serialport.c b/serialport.c
index 9ebc2da..074534e 100644
--- a/serialport.c
+++ b/serialport.c
@@ -21,138 +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>
-#include <stdio.h>
-#include <stdarg.h>
-#ifdef _WIN32
-#include <windows.h>
-#include <setupapi.h>
-#include <cfgmgr32.h>
-#include <usbioctl.h>
-#include <tchar.h>
-#else
-#include <limits.h>
-#include <termios.h>
-#include <sys/ioctl.h>
-#include <sys/time.h>
-#include <limits.h>
-#include <poll.h>
-#endif
-#ifdef __APPLE__
-#include <CoreFoundation/CoreFoundation.h>
-#include <IOKit/IOKitLib.h>
-#include <IOKit/serial/IOSerialKeys.h>
-#include <IOKit/serial/ioss.h>
-#include <sys/syslimits.h>
-#endif
-#ifdef __linux__
-#include <dirent.h>
-#ifndef __ANDROID__
-#include "linux/serial.h"
-#endif
-#include "linux_termios.h"
-
-/* TCGETX/TCSETX is not available everywhere. */
-#if defined(TCGETX) && defined(TCSETX) && defined(HAVE_TERMIOX)
-#define USE_TERMIOX
-#endif
-#endif
-
-/* TIOCINQ/TIOCOUTQ is not available everywhere. */
-#if !defined(TIOCINQ) && defined(FIONREAD)
-#define TIOCINQ FIONREAD
-#endif
-#if !defined(TIOCOUTQ) && defined(FIONWRITE)
-#define TIOCOUTQ FIONWRITE
-#endif
-
-/* Non-standard baudrates are not available everywhere. */
-#if defined(HAVE_TERMIOS_SPEED) || defined(HAVE_TERMIOS2_SPEED)
-#define USE_TERMIOS_SPEED
-#endif
-
 #include "libserialport.h"
+#include "libserialport_internal.h"
 
-struct sp_port {
-	char *name;
-	char *description;
-	enum sp_transport transport;
-	int usb_bus;
-	int usb_address;
-	int usb_vid;
-	int usb_pid;
-	char *usb_manufacturer;
-	char *usb_product;
-	char *usb_serial;
-	char *bluetooth_address;
-#ifdef _WIN32
-	char *usb_path;
-	HANDLE hdl;
-	COMMTIMEOUTS timeouts;
-	OVERLAPPED write_ovl;
-	OVERLAPPED read_ovl;
-	OVERLAPPED wait_ovl;
-	DWORD events;
-	BYTE pending_byte;
-	BOOL writing;
-#else
-	int fd;
-#endif
-};
-
-struct sp_port_config {
-	int baudrate;
-	int bits;
-	enum sp_parity parity;
-	int stopbits;
-	enum sp_rts rts;
-	enum sp_cts cts;
-	enum sp_dtr dtr;
-	enum sp_dsr dsr;
-	enum sp_xonxoff xon_xoff;
-};
-
-struct port_data {
-#ifdef _WIN32
-	DCB dcb;
-#else
-	struct termios term;
-	int controlbits;
-	int termiox_supported;
-	int rts_flow;
-	int cts_flow;
-	int dtr_flow;
-	int dsr_flow;
-#endif
-};
-
-#ifdef _WIN32
-typedef HANDLE event_handle;
-#else
-typedef int event_handle;
-#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
@@ -172,782 +44,22 @@ const struct std_baudrate std_baudrates[] = {
 #endif
 };
 
-void (*sp_debug_handler)(const char *format, ...) = sp_default_debug_handler;
-
-#define ARRAY_SIZE(x) (sizeof(x) / sizeof(x[0]))
 #define NUM_STD_BAUDRATES ARRAY_SIZE(std_baudrates)
 
-/* Debug output macros. */
-#define DEBUG(fmt, ...) do { if (sp_debug_handler) sp_debug_handler(fmt ".\n", ##__VA_ARGS__); } while (0)
-#define DEBUG_ERROR(err, fmt, ...) DEBUG("%s returning " #err ": " fmt, __func__, ##__VA_ARGS__)
-#define DEBUG_FAIL(fmt, ...) do {               \
-	char *errmsg = sp_last_error_message(); \
-	DEBUG("%s returning SP_ERR_FAIL: "fmt": %s", __func__,##__VA_ARGS__,errmsg); \
-	sp_free_error_message(errmsg); \
-} while (0);
-#define RETURN() do { DEBUG("%s returning", __func__); return; } while(0)
-#define RETURN_CODE(x) do { DEBUG("%s returning " #x, __func__); return x; } while (0)
-#define RETURN_CODEVAL(x) do { \
-	switch (x) { \
-		case SP_OK: RETURN_CODE(SP_OK); \
-		case SP_ERR_ARG: RETURN_CODE(SP_ERR_ARG); \
-		case SP_ERR_FAIL: RETURN_CODE(SP_ERR_FAIL); \
-		case SP_ERR_MEM: RETURN_CODE(SP_ERR_MEM); \
-		case SP_ERR_SUPP: RETURN_CODE(SP_ERR_SUPP); \
-	} \
-} while (0)
-#define RETURN_OK() RETURN_CODE(SP_OK);
-#define RETURN_ERROR(err, ...) do { DEBUG_ERROR(err, __VA_ARGS__); return err; } while (0)
-#define RETURN_FAIL(...) do { DEBUG_FAIL(__VA_ARGS__); return SP_ERR_FAIL; } while (0)
-#define RETURN_VALUE(fmt, x) do { \
-	typeof(x) _x = x; \
-	DEBUG("%s returning " fmt, __func__, _x); \
-	return _x; \
-} while (0)
-#define SET_ERROR(val, err, msg) do { DEBUG_ERROR(err, msg); val = err; } while (0)
-#define SET_FAIL(val, msg) do { DEBUG_FAIL(msg); val = SP_ERR_FAIL; } while (0)
-#define TRACE(fmt, ...) DEBUG("%s(" fmt ") called", __func__, ##__VA_ARGS__)
-
-#define TRY(x) do { int ret = x; if (ret != SP_OK) RETURN_CODEVAL(ret); } while (0)
+void (*sp_debug_handler)(const char *format, ...) = sp_default_debug_handler;
 
-/* Helper functions. */
 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);
 
-#ifdef _WIN32
-
-/* USB path is a string of at most 8 decimal numbers < 128 separated by dots */
-#define MAX_USB_PATH  (8*3 + 7*1 + 1)
-
-static char *wc_to_utf8(PWCHAR wc_buffer, ULONG size)
-{
-	WCHAR wc_str[size/sizeof(WCHAR)+1];
-	char *utf8_str;
-
-	/* zero terminate the wide char string */
-	memcpy(wc_str, wc_buffer, size);
-	wc_str[sizeof(wc_str)-1] = 0;
-
-	/* compute the size of the utf8 converted string */
-	if (!(size = WideCharToMultiByte(CP_ACP, WC_NO_BEST_FIT_CHARS, wc_str, -1,
-	                                 NULL, 0, NULL, NULL)))
-		return NULL;
-
-	/* allocate utf8 output buffer */
-	if (!(utf8_str = malloc(size)))
-		return NULL;
-
-	/* actually converted to utf8 */
-	if (!WideCharToMultiByte(CP_ACP, WC_NO_BEST_FIT_CHARS, wc_str, -1,
-	                         utf8_str, size, NULL, NULL)) {
-		free(utf8_str);
-		return NULL;
-	}
-
-	return utf8_str;
-}
-
-static char *get_root_hub_name(HANDLE host_controller)
-{
-	USB_ROOT_HUB_NAME  root_hub_name;
-	PUSB_ROOT_HUB_NAME root_hub_name_wc;
-	char *root_hub_name_utf8;
-	ULONG size = 0;
-
-	/* compute the size of the root hub name string */
-	if (!DeviceIoControl(host_controller, IOCTL_USB_GET_ROOT_HUB_NAME, 0, 0,
-	                     &root_hub_name, sizeof(root_hub_name), &size, NULL))
-		return NULL;
-
-	/* allocate wide char root hub name string */
-	size = root_hub_name.ActualLength;
-	if (!(root_hub_name_wc = malloc(size)))
-		return NULL;
-
-	/* actually get the root hub name string */
-	if (!DeviceIoControl(host_controller, IOCTL_USB_GET_ROOT_HUB_NAME,
-	                     NULL, 0, root_hub_name_wc, size, &size, NULL)) {
-		free(root_hub_name_wc);
-		return NULL;
-	}
-
-	/* convert the root hub name string to utf8 */
-	root_hub_name_utf8 = wc_to_utf8(root_hub_name_wc->RootHubName, size);
-	free(root_hub_name_wc);
-	return root_hub_name_utf8;
-}
-
-static char *get_external_hub_name(HANDLE hub, ULONG connection_index)
-{
-	USB_NODE_CONNECTION_NAME  ext_hub_name;
-	PUSB_NODE_CONNECTION_NAME ext_hub_name_wc;
-	char *ext_hub_name_utf8;
-	ULONG size;
-
-	/* compute the size of the external hub name string */
-	ext_hub_name.ConnectionIndex = connection_index;
-	if (!DeviceIoControl(hub, IOCTL_USB_GET_NODE_CONNECTION_NAME,
-	                     &ext_hub_name, sizeof(ext_hub_name),
-	                     &ext_hub_name, sizeof(ext_hub_name), &size, NULL))
-		return NULL;
-
-	/* allocate wide char external hub name string */
-	size = ext_hub_name.ActualLength;
-	if (size <= sizeof(ext_hub_name)
-	    || !(ext_hub_name_wc = malloc(size)))
-		return NULL;
-
-	/* get the name of the external hub attached to the specified port */
-	ext_hub_name_wc->ConnectionIndex = connection_index;
-	if (!DeviceIoControl(hub, IOCTL_USB_GET_NODE_CONNECTION_NAME,
-	                     ext_hub_name_wc, size,
-	                     ext_hub_name_wc, size, &size, NULL)) {
-		free(ext_hub_name_wc);
-		return NULL;
-	}
-
-	/* convert the external hub name string to utf8 */
-	ext_hub_name_utf8 = wc_to_utf8(ext_hub_name_wc->NodeName, size);
-	free(ext_hub_name_wc);
-	return ext_hub_name_utf8;
-}
-
-static char *get_string_descriptor(HANDLE hub_device, ULONG connection_index,
-                                   UCHAR descriptor_index)
-{
-	char desc_req_buf[sizeof(USB_DESCRIPTOR_REQUEST) +
-	                  MAXIMUM_USB_STRING_LENGTH] = { 0 };
-	PUSB_DESCRIPTOR_REQUEST desc_req = (void *) desc_req_buf;
-	PUSB_STRING_DESCRIPTOR  desc     = (void *) (desc_req + 1);
-	ULONG size = sizeof(desc_req_buf);
-
-	desc_req->ConnectionIndex     = connection_index;
-	desc_req->SetupPacket.wValue  = (USB_STRING_DESCRIPTOR_TYPE << 8)
-	                                | descriptor_index;
-	desc_req->SetupPacket.wIndex  = 0;
-	desc_req->SetupPacket.wLength = size - sizeof(*desc_req);
-
-	if (!DeviceIoControl(hub_device,
-	                     IOCTL_USB_GET_DESCRIPTOR_FROM_NODE_CONNECTION,
-	                     desc_req, size, desc_req, size, &size, NULL)
-	    || size < 2
-	    || desc->bDescriptorType != USB_STRING_DESCRIPTOR_TYPE
-	    || desc->bLength != size - sizeof(*desc_req)
-	    || desc->bLength % 2)
-		return NULL;
-
-	return wc_to_utf8(desc->bString, desc->bLength);
-}
-
-static void enumerate_hub(struct sp_port *port, char *hub_name,
-                          char *parent_path);
-
-static void enumerate_hub_ports(struct sp_port *port, HANDLE hub_device,
-                                ULONG nb_ports, char *parent_path)
-{
-	char path[MAX_USB_PATH];
-	ULONG index = 0;
-
-	for (index = 1; index <= nb_ports; index++) {
-		PUSB_NODE_CONNECTION_INFORMATION_EX connection_info_ex;
-		ULONG size = sizeof(*connection_info_ex) + 30*sizeof(USB_PIPE_INFO);
-
-		if (!(connection_info_ex = malloc(size)))
-			break;
-
-		connection_info_ex->ConnectionIndex = index;
-		if (!DeviceIoControl(hub_device,
-		                     IOCTL_USB_GET_NODE_CONNECTION_INFORMATION_EX,
-		                     connection_info_ex, size,
-		                     connection_info_ex, size, &size, NULL)) {
-			/* try to get CONNECTION_INFORMATION if CONNECTION_INFORMATION_EX
-			   did not work */
-			PUSB_NODE_CONNECTION_INFORMATION connection_info;
-
-			size = sizeof(*connection_info) + 30*sizeof(USB_PIPE_INFO);
-			if (!(connection_info = malloc(size))) {
-				free(connection_info_ex);
-				continue;
-			}
-			connection_info->ConnectionIndex = index;
-			if (!DeviceIoControl(hub_device,
-			                     IOCTL_USB_GET_NODE_CONNECTION_INFORMATION,
-			                     connection_info, size,
-			                     connection_info, size, &size, NULL)) {
-				free(connection_info);
-				free(connection_info_ex);
-				continue;
-			}
-
-			connection_info_ex->ConnectionIndex = connection_info->ConnectionIndex;
-			connection_info_ex->DeviceDescriptor = connection_info->DeviceDescriptor;
-			connection_info_ex->DeviceIsHub = connection_info->DeviceIsHub;
-			connection_info_ex->DeviceAddress = connection_info->DeviceAddress;
-			free(connection_info);
-		}
-
-		if (connection_info_ex->DeviceIsHub) {
-			/* recursively enumerate external hub */
-			PCHAR ext_hub_name;
-			if ((ext_hub_name = get_external_hub_name(hub_device, index))) {
-				snprintf(path, sizeof(path), "%s%d.",
-				         parent_path, connection_info_ex->ConnectionIndex);
-				enumerate_hub(port, ext_hub_name, path);
-			}
-			free(connection_info_ex);
-		} else {
-			snprintf(path, sizeof(path), "%s%d",
-			         parent_path, connection_info_ex->ConnectionIndex);
-
-			/* check if this device is the one we search for */
-			if (strcmp(path, port->usb_path)) {
-				free(connection_info_ex);
-				continue;
-			}
-
-			/* finally grab detailed informations regarding the device */
-			port->usb_address = connection_info_ex->DeviceAddress + 1;
-			port->usb_vid = connection_info_ex->DeviceDescriptor.idVendor;
-			port->usb_pid = connection_info_ex->DeviceDescriptor.idProduct;
-
-			if (connection_info_ex->DeviceDescriptor.iManufacturer)
-				port->usb_manufacturer = get_string_descriptor(hub_device,index,
-				           connection_info_ex->DeviceDescriptor.iManufacturer);
-			if (connection_info_ex->DeviceDescriptor.iProduct)
-				port->usb_product = get_string_descriptor(hub_device, index,
-				           connection_info_ex->DeviceDescriptor.iProduct);
-			if (connection_info_ex->DeviceDescriptor.iSerialNumber)
-				port->usb_serial = get_string_descriptor(hub_device, index,
-				           connection_info_ex->DeviceDescriptor.iSerialNumber);
-
-			free(connection_info_ex);
-			break;
-		}
-	}
-}
-
-static void enumerate_hub(struct sp_port *port, char *hub_name,
-                          char *parent_path)
-{
-	USB_NODE_INFORMATION hub_info;
-	HANDLE hub_device;
-	ULONG size = sizeof(hub_info);
-	char *device_name;
-
-	/* open the hub with its full name */
-	if (!(device_name = malloc(strlen("\\\\.\\") + strlen(hub_name) + 1)))
-		return;
-	strcpy(device_name, "\\\\.\\");
-	strcat(device_name, hub_name);
-	hub_device = CreateFile(device_name, GENERIC_WRITE, FILE_SHARE_WRITE,
-	                        NULL, OPEN_EXISTING, 0, NULL);
-	free(device_name);
-	if (hub_device == INVALID_HANDLE_VALUE)
-		return;
-
-	/* get the number of ports of the hub */
-	if (DeviceIoControl(hub_device, IOCTL_USB_GET_NODE_INFORMATION,
-	                    &hub_info, size, &hub_info, size, &size, NULL))
-		/* enumarate the ports of the hub */
-		enumerate_hub_ports(port, hub_device,
-		   hub_info.u.HubInformation.HubDescriptor.bNumberOfPorts, parent_path);
-
-	CloseHandle(hub_device);
-}
-
-static void enumerate_host_controller(struct sp_port *port,
-                                      HANDLE host_controller_device)
-{
-	char *root_hub_name;
-
-	if ((root_hub_name = get_root_hub_name(host_controller_device))) {
-		enumerate_hub(port, root_hub_name, "");
-		free(root_hub_name);
-	}
-}
-
-static void get_usb_details(struct sp_port *port, DEVINST dev_inst_match)
-{
-	HDEVINFO device_info;
-	SP_DEVINFO_DATA device_info_data;
-	ULONG i, size = 0;
-
-	device_info = SetupDiGetClassDevs(&GUID_CLASS_USB_HOST_CONTROLLER,NULL,NULL,
-	                                  DIGCF_PRESENT | DIGCF_DEVICEINTERFACE);
-	device_info_data.cbSize = sizeof(device_info_data);
-
-	for (i=0; SetupDiEnumDeviceInfo(device_info, i, &device_info_data); i++) {
-		SP_DEVICE_INTERFACE_DATA device_interface_data;
-		PSP_DEVICE_INTERFACE_DETAIL_DATA device_detail_data;
-		DEVINST dev_inst = dev_inst_match;
-		HANDLE host_controller_device;
-
-		device_interface_data.cbSize = sizeof(device_interface_data);
-		if (!SetupDiEnumDeviceInterfaces(device_info, 0,
-		                                 &GUID_CLASS_USB_HOST_CONTROLLER,
-		                                 i, &device_interface_data))
-			continue;
-
-		if (!SetupDiGetDeviceInterfaceDetail(device_info,&device_interface_data,
-		                                     NULL, 0, &size, NULL)
-		    && GetLastError() != ERROR_INSUFFICIENT_BUFFER)
-			continue;
-
-		if (!(device_detail_data = malloc(size)))
-			continue;
-		device_detail_data->cbSize = sizeof(*device_detail_data);
-		if (!SetupDiGetDeviceInterfaceDetail(device_info,&device_interface_data,
-		                                     device_detail_data, size, &size,
-		                                     NULL)) {
-			free(device_detail_data);
-			continue;
-		}
-
-		while (CM_Get_Parent(&dev_inst, dev_inst, 0) == CR_SUCCESS
-		       && dev_inst != device_info_data.DevInst) { }
-		if (dev_inst != device_info_data.DevInst) {
-			free(device_detail_data);
-			continue;
-		}
-
-		port->usb_bus = i + 1;
-
-		host_controller_device = CreateFile(device_detail_data->DevicePath,
-		                                    GENERIC_WRITE, FILE_SHARE_WRITE,
-		                                    NULL, OPEN_EXISTING, 0, NULL);
-		if (host_controller_device != INVALID_HANDLE_VALUE) {
-			enumerate_host_controller(port, host_controller_device);
-			CloseHandle(host_controller_device);
-		}
-		free(device_detail_data);
-	}
-
-	SetupDiDestroyDeviceInfoList(device_info);
-	return;
-}
-
-#endif /* _WIN32 */
-
-static enum sp_return sp_get_port_details(struct sp_port *port)
-{
-	/* Description limited to 127 char,
-	   anything longer would not be user friendly anyway */
-	char description[128];
-#ifndef _WIN32
-	int bus, address, vid, pid = -1;
-	char manufacturer[128], product[128], serial[128];
-	char baddr[32];
-#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;
-
-#ifdef _WIN32
-	SP_DEVINFO_DATA device_info_data = { .cbSize = sizeof(device_info_data) };
-	HDEVINFO device_info;
-	int i;
-
-	device_info = SetupDiGetClassDevs(NULL, 0, 0,
-	                                  DIGCF_PRESENT | DIGCF_ALLCLASSES);
-	if (device_info == INVALID_HANDLE_VALUE)
-		RETURN_FAIL("SetupDiGetClassDevs() failed");
-
-	for (i=0; SetupDiEnumDeviceInfo(device_info, i, &device_info_data); i++) {
-		HKEY device_key;
-		DEVINST dev_inst;
-		char value[8], class[16];
-		DWORD size, type;
-		CONFIGRET cr;
-
-		/* check if this is the device we are looking for */
-		if (!(device_key = SetupDiOpenDevRegKey(device_info, &device_info_data,
-		                                        DICS_FLAG_GLOBAL, 0,
-		                                        DIREG_DEV, KEY_QUERY_VALUE)))
-			continue;
-		size = sizeof(value);
-		if (RegQueryValueExA(device_key, "PortName", NULL, &type, (LPBYTE)value,
-		                     &size) != ERROR_SUCCESS || type != REG_SZ)
-			continue;
-		RegCloseKey(device_key);
-		value[sizeof(value)-1] = 0;
-		if (strcmp(value, port->name))
-			continue;
-
-		/* check port transport type */
-		dev_inst = device_info_data.DevInst;
-		size = sizeof(class);
-		cr = CR_FAILURE;
-		while (CM_Get_Parent(&dev_inst, dev_inst, 0) == CR_SUCCESS &&
-		       (cr = CM_Get_DevNode_Registry_PropertyA(dev_inst,
-		                 CM_DRP_CLASS, 0, class, &size, 0)) != CR_SUCCESS) { }
-		if (cr == CR_SUCCESS) {
-			if (!strcmp(class, "USB"))
-				port->transport = SP_TRANSPORT_USB;
-		}
-
-		/* get port description (friendly name) */
-		dev_inst = device_info_data.DevInst;
-		size = sizeof(description);
-		while ((cr = CM_Get_DevNode_Registry_PropertyA(dev_inst,
-		          CM_DRP_FRIENDLYNAME, 0, description, &size, 0)) != CR_SUCCESS
-		       && CM_Get_Parent(&dev_inst, dev_inst, 0) == CR_SUCCESS) { }
-		if (cr == CR_SUCCESS)
-			port->description = strdup(description);
-
-		/* get more informations for USB connected ports */
-		if (port->transport == SP_TRANSPORT_USB) {
-			char usb_path[MAX_USB_PATH] = "", tmp[MAX_USB_PATH];
-			char device_id[MAX_DEVICE_ID_LEN];
-
-			/* recurse over parents to build the USB device path */
-			dev_inst = device_info_data.DevInst;
-			do {
-				/* verify that this layer of the tree is USB related */
-				if (CM_Get_Device_IDA(dev_inst, device_id,
-				                      sizeof(device_id), 0) != CR_SUCCESS
-				    || strncmp(device_id, "USB\\", 4))
-					continue;
-
-				/* discard one layer for composite devices */
-				char compat_ids[512], *p = compat_ids;
-				size = sizeof(compat_ids);
-				if (CM_Get_DevNode_Registry_PropertyA(dev_inst,
-				                                      CM_DRP_COMPATIBLEIDS, 0,
-				                                      &compat_ids,
-				                                      &size, 0) == CR_SUCCESS) {
-					while (*p) {
-						if (!strncmp(p, "USB\\COMPOSITE", 13))
-							break;
-						p += strlen(p) + 1;
-					}
-					if (*p)
-						continue;
-				}
-
-				/* stop the recursion when reaching the USB root */
-				if (!strncmp(device_id, "USB\\ROOT", 8))
-					break;
-
-				/* prepend the address of current USB layer to the USB path */
-				DWORD address;
-				size = sizeof(address);
-				if (CM_Get_DevNode_Registry_PropertyA(dev_inst, CM_DRP_ADDRESS,
-				                        0, &address, &size, 0) == CR_SUCCESS) {
-					strcpy(tmp, usb_path);
-					snprintf(usb_path, sizeof(usb_path), "%d%s%s",
-					         (int)address, *tmp ? "." : "", tmp);
-				}
-			} while (CM_Get_Parent(&dev_inst, dev_inst, 0) == CR_SUCCESS);
-
-			port->usb_path = strdup(usb_path);
-
-			/* wake up the USB device to be able to read string descriptor */
-			char *escaped_port_name;
-			HANDLE handle;
-			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);
-			handle = CreateFile(escaped_port_name, GENERIC_READ, 0, 0,
-			                    OPEN_EXISTING,
-			                    FILE_ATTRIBUTE_NORMAL|FILE_FLAG_OVERLAPPED, 0);
-			free(escaped_port_name);
-			CloseHandle(handle);
-
-			/* retrive USB device details from the device descriptor */
-			get_usb_details(port, device_info_data.DevInst);
-		}
-		break;
-	}
-#elif defined(__APPLE__)
-	CFMutableDictionaryRef classes;
-	io_iterator_t iter;
-	io_object_t ioport;
-	CFTypeRef cf_property, cf_bus, cf_address, cf_vendor, cf_product;
-	Boolean result;
-	char path[PATH_MAX];
-
-	DEBUG("Getting serial port list");
-	if (!(classes = IOServiceMatching(kIOSerialBSDServiceValue)))
-		RETURN_FAIL("IOServiceMatching() failed");
-
-	if (IOServiceGetMatchingServices(kIOMasterPortDefault, classes,
-	                                 &iter) != KERN_SUCCESS)
-		RETURN_FAIL("IOServiceGetMatchingServices() failed");
-
-	DEBUG("Iterating over results");
-	while ((ioport = IOIteratorNext(iter))) {
-		if (!(cf_property = IORegistryEntryCreateCFProperty(ioport,
-		            CFSTR(kIOCalloutDeviceKey), kCFAllocatorDefault, 0))) {
-			IOObjectRelease(ioport);
-			continue;
-		}
-		result = CFStringGetCString(cf_property, path, sizeof(path),
-		                            kCFStringEncodingASCII);
-		CFRelease(cf_property);
-		if (!result || strcmp(path, port->name)) {
-			IOObjectRelease(ioport);
-			continue;
-		}
-		DEBUG("Found port %s", path);
-
-		IORegistryEntryGetParentEntry(ioport, kIOServicePlane, &ioparent);
-		if ((cf_property=IORegistryEntrySearchCFProperty(ioparent,kIOServicePlane,
-		           CFSTR("IOProviderClass"), kCFAllocatorDefault,
-		           kIORegistryIterateRecursively | kIORegistryIterateParents))) {
-			if (CFStringGetCString(cf_property, class, sizeof(class),
-			                       kCFStringEncodingASCII) &&
-			    strstr(class, "USB")) {
-				DEBUG("Found USB class device");
-				port->transport = SP_TRANSPORT_USB;
-			}
-			CFRelease(cf_property);
-		}
-		IOObjectRelease(ioparent);
-
-		if ((cf_property = IORegistryEntrySearchCFProperty(ioport,kIOServicePlane,
-		         CFSTR("USB Interface Name"), kCFAllocatorDefault,
-		         kIORegistryIterateRecursively | kIORegistryIterateParents)) ||
-		    (cf_property = IORegistryEntrySearchCFProperty(ioport,kIOServicePlane,
-		         CFSTR("USB Product Name"), kCFAllocatorDefault,
-		         kIORegistryIterateRecursively | kIORegistryIterateParents)) ||
-		    (cf_property = IORegistryEntrySearchCFProperty(ioport,kIOServicePlane,
-		         CFSTR("Product Name"), kCFAllocatorDefault,
-		         kIORegistryIterateRecursively | kIORegistryIterateParents)) ||
-		    (cf_property = IORegistryEntryCreateCFProperty(ioport,
-		         CFSTR(kIOTTYDeviceKey), kCFAllocatorDefault, 0))) {
-			if (CFStringGetCString(cf_property, description, sizeof(description),
-			                       kCFStringEncodingASCII)) {
-				DEBUG("Found description %s", description);
-				port->description = strdup(description);
-			}
-			CFRelease(cf_property);
-		} else {
-			DEBUG("No description for this device");
-		}
-
-		cf_bus = IORegistryEntrySearchCFProperty(ioport, kIOServicePlane,
-		                                         CFSTR("USBBusNumber"),
-		                                         kCFAllocatorDefault,
-		                                         kIORegistryIterateRecursively
-		                                         | kIORegistryIterateParents);
-		cf_address = IORegistryEntrySearchCFProperty(ioport, kIOServicePlane,
-		                                         CFSTR("USB Address"),
-		                                         kCFAllocatorDefault,
-		                                         kIORegistryIterateRecursively
-		                                         | kIORegistryIterateParents);
-		if (cf_bus && cf_address &&
-		    CFNumberGetValue(cf_bus    , kCFNumberIntType, &bus) &&
-		    CFNumberGetValue(cf_address, kCFNumberIntType, &address)) {
-			DEBUG("Found matching USB bus:address %03d:%03d", bus, address);
-			port->usb_bus = bus;
-			port->usb_address = address;
-		}
-		if (cf_bus    )  CFRelease(cf_bus);
-		if (cf_address)  CFRelease(cf_address);
-
-		cf_vendor = IORegistryEntrySearchCFProperty(ioport, kIOServicePlane,
-		                                         CFSTR("idVendor"),
-		                                         kCFAllocatorDefault,
-		                                         kIORegistryIterateRecursively
-		                                         | kIORegistryIterateParents);
-		cf_product = IORegistryEntrySearchCFProperty(ioport, kIOServicePlane,
-		                                         CFSTR("idProduct"),
-		                                         kCFAllocatorDefault,
-		                                         kIORegistryIterateRecursively
-		                                         | kIORegistryIterateParents);
-		if (cf_vendor && cf_product &&
-		    CFNumberGetValue(cf_vendor , kCFNumberIntType, &vid) &&
-		    CFNumberGetValue(cf_product, kCFNumberIntType, &pid)) {
-			DEBUG("Found matching USB vid:pid %04X:%04X", vid, pid);
-			port->usb_vid = vid;
-			port->usb_pid = pid;
-		}
-		if (cf_vendor )  CFRelease(cf_vendor);
-		if (cf_product)  CFRelease(cf_product);
-
-		if ((cf_property = IORegistryEntrySearchCFProperty(ioport,kIOServicePlane,
-		         CFSTR("USB Vendor Name"), kCFAllocatorDefault,
-		         kIORegistryIterateRecursively | kIORegistryIterateParents))) {
-			if (CFStringGetCString(cf_property, manufacturer, sizeof(manufacturer),
-			                       kCFStringEncodingASCII)) {
-				DEBUG("Found manufacturer %s", manufacturer);
-				port->usb_manufacturer = strdup(manufacturer);
-			}
-			CFRelease(cf_property);
-		}
-
-		if ((cf_property = IORegistryEntrySearchCFProperty(ioport,kIOServicePlane,
-		         CFSTR("USB Product Name"), kCFAllocatorDefault,
-		         kIORegistryIterateRecursively | kIORegistryIterateParents))) {
-			if (CFStringGetCString(cf_property, product, sizeof(product),
-			                       kCFStringEncodingASCII)) {
-				DEBUG("Found product name %s", product);
-				port->usb_product = strdup(product);
-			}
-			CFRelease(cf_property);
-		}
-
-		if ((cf_property = IORegistryEntrySearchCFProperty(ioport,kIOServicePlane,
-		         CFSTR("USB Serial Number"), kCFAllocatorDefault,
-		         kIORegistryIterateRecursively | kIORegistryIterateParents))) {
-			if (CFStringGetCString(cf_property, serial, sizeof(serial),
-			                       kCFStringEncodingASCII)) {
-				DEBUG("Found serial number %s", serial);
-				port->usb_serial = strdup(serial);
-			}
-			CFRelease(cf_property);
-		}
-
-		IOObjectRelease(ioport);
-		break;
-	}
-	IOObjectRelease(iter);
-#elif defined(__linux__)
-	const char dir_name[] = "/sys/class/tty/%s/device/%s%s";
-	char sub_dir[32] = "", file_name[PATH_MAX];
-	char *ptr, *dev = port->name + 5;
-	FILE *file;
-	int i, count;
-
-	if (strncmp(port->name, "/dev/", 5))
-		RETURN_ERROR(SP_ERR_ARG, "Device name not recognized (%s)", port->name);
-
-	snprintf(file_name, sizeof(file_name), "/sys/class/tty/%s", dev);
-	count = readlink(file_name, file_name, sizeof(file_name));
-	if (count <= 0 || count >= (int) sizeof(file_name)-1)
-		RETURN_ERROR(SP_ERR_ARG, "Device not found (%s)", port->name);
-	file_name[count] = 0;
-	if (strstr(file_name, "bluetooth"))
-		port->transport = SP_TRANSPORT_BLUETOOTH;
-	else if (strstr(file_name, "usb"))
-		port->transport = SP_TRANSPORT_USB;
-
-	if (port->transport == SP_TRANSPORT_USB) {
-		for (i=0; i<5; i++) {
-			strcat(sub_dir, "../");
-
-			snprintf(file_name,sizeof(file_name),dir_name,dev,sub_dir,"busnum");
-			if (!(file = fopen(file_name, "r")))
-				continue;
-			count = fscanf(file, "%d", &bus);
-			fclose(file);
-			if (count != 1)
-				continue;
-
-			snprintf(file_name,sizeof(file_name),dir_name,dev,sub_dir,"devnum");
-			if (!(file = fopen(file_name, "r")))
-				continue;
-			count = fscanf(file, "%d", &address);
-			fclose(file);
-			if (count != 1)
-				continue;
-
-			snprintf(file_name,sizeof(file_name),dir_name,dev,sub_dir,"idVendor");
-			if (!(file = fopen(file_name, "r")))
-				continue;
-			count = fscanf(file, "%4x", &vid);
-			fclose(file);
-			if (count != 1)
-				continue;
-
-			snprintf(file_name,sizeof(file_name),dir_name,dev,sub_dir,"idProduct");
-			if (!(file = fopen(file_name, "r")))
-				continue;
-			count = fscanf(file, "%4x", &pid);
-			fclose(file);
-			if (count != 1)
-				continue;
-
-			port->usb_bus = bus;
-			port->usb_address = address;
-			port->usb_vid = vid;
-			port->usb_pid = pid;
-
-			snprintf(file_name,sizeof(file_name),dir_name,dev,sub_dir,"product");
-			if ((file = fopen(file_name, "r"))) {
-				if ((ptr = fgets(description, sizeof(description), file))) {
-					ptr = description + strlen(description) - 1;
-					if (ptr >= description && *ptr == '\n')
-						*ptr = 0;
-					port->description = strdup(description);
-				}
-				fclose(file);
-			}
-			if (!file || !ptr)
-				port->description = strdup(dev);
-
-			snprintf(file_name,sizeof(file_name),dir_name,dev,sub_dir,"manufacturer");
-			if ((file = fopen(file_name, "r"))) {
-				if ((ptr = fgets(manufacturer, sizeof(manufacturer), file))) {
-					ptr = manufacturer + strlen(manufacturer) - 1;
-					if (ptr >= manufacturer && *ptr == '\n')
-						*ptr = 0;
-					port->usb_manufacturer = strdup(manufacturer);
-				}
-				fclose(file);
-			}
-
-			snprintf(file_name,sizeof(file_name),dir_name,dev,sub_dir,"product");
-			if ((file = fopen(file_name, "r"))) {
-				if ((ptr = fgets(product, sizeof(product), file))) {
-					ptr = product + strlen(product) - 1;
-					if (ptr >= product && *ptr == '\n')
-						*ptr = 0;
-					port->usb_product = strdup(product);
-				}
-				fclose(file);
-			}
-
-			snprintf(file_name,sizeof(file_name),dir_name,dev,sub_dir,"serial");
-			if ((file = fopen(file_name, "r"))) {
-				if ((ptr = fgets(serial, sizeof(serial), file))) {
-					ptr = serial + strlen(serial) - 1;
-					if (ptr >= serial && *ptr == '\n')
-						*ptr = 0;
-					port->usb_serial = strdup(serial);
-				}
-				fclose(file);
-			}
-
-			break;
-		}
-	} else {
-		port->description = strdup(dev);
-
-		if (port->transport == SP_TRANSPORT_BLUETOOTH) {
-			snprintf(file_name, sizeof(file_name), dir_name, dev, "", "address");
-			if ((file = fopen(file_name, "r"))) {
-				if ((ptr = fgets(baddr, sizeof(baddr), file))) {
-					ptr = baddr + strlen(baddr) - 1;
-					if (ptr >= baddr && *ptr == '\n')
-						*ptr = 0;
-					port->bluetooth_address = strdup(baddr);
-				}
-				fclose(file);
-			}
-		}
-	}
-#else
-	DEBUG("Port details not supported on this platform");
-#endif
-
-	RETURN_OK();
-}
-
-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);
@@ -960,7 +72,7 @@ enum sp_return sp_get_port_by_name(const char *portname, struct sp_port **port_p
 	if (!portname)
 		RETURN_ERROR(SP_ERR_ARG, "Null port name");
 
-	DEBUG("Building structure for port %s", portname);
+	DEBUG_FMT("Building structure for port %s", portname);
 
 	if (!(port = malloc(sizeof(struct sp_port))))
 		RETURN_ERROR(SP_ERR_MEM, "Port structure malloc failed");
@@ -975,53 +87,67 @@ enum sp_return sp_get_port_by_name(const char *portname, struct sp_port **port_p
 	memcpy(port->name, portname, len);
 
 #ifdef _WIN32
+	port->usb_path = NULL;
 	port->hdl = INVALID_HANDLE_VALUE;
 #else
 	port->fd = -1;
 #endif
 
-	if ((ret = sp_get_port_details(port)) != SP_OK) {
+	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_OK();
 }
 
-char *sp_get_port_name(const struct sp_port *port)
+SP_API char *sp_get_port_name(const struct sp_port *port)
 {
 	TRACE("%p", port);
 
 	if (!port)
 		return NULL;
 
-	RETURN_VALUE("%s", port->name);
+	RETURN_STRING(port->name);
 }
 
-char *sp_get_port_description(struct sp_port *port)
+SP_API char *sp_get_port_description(const struct sp_port *port)
 {
 	TRACE("%p", port);
 
 	if (!port || !port->description)
 		return NULL;
 
-	RETURN_VALUE("%s", port->description);
+	RETURN_STRING(port->description);
 }
 
-enum sp_transport sp_get_port_transport(struct sp_port *port)
+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_VALUE("%d", port->transport);
+	RETURN_INT(port->transport);
 }
 
-enum sp_return sp_get_port_usb_bus_address(const struct sp_port *port,
-                                           int *usb_bus, int *usb_address)
+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);
 
@@ -1029,15 +155,19 @@ enum sp_return sp_get_port_usb_bus_address(const struct sp_port *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;
+	if (usb_bus)
+		*usb_bus = port->usb_bus;
+	if (usb_address)
+		*usb_address = port->usb_address;
 
 	RETURN_OK();
 }
 
-enum sp_return sp_get_port_usb_vid_pid(const struct sp_port *port,
-                                       int *usb_vid, int *usb_pid)
+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);
 
@@ -1045,44 +175,48 @@ enum sp_return sp_get_port_usb_vid_pid(const struct sp_port *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;
+	if (usb_vid)
+		*usb_vid = port->usb_vid;
+	if (usb_pid)
+		*usb_pid = port->usb_pid;
 
 	RETURN_OK();
 }
 
-char *sp_get_port_usb_manufacturer(const struct sp_port *port)
+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_VALUE("%s", port->usb_manufacturer);
+	RETURN_STRING(port->usb_manufacturer);
 }
 
-char *sp_get_port_usb_product(const struct sp_port *port)
+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_VALUE("%s", port->usb_product);
+	RETURN_STRING(port->usb_product);
 }
 
-char *sp_get_port_usb_serial(const struct sp_port *port)
+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_VALUE("%s", port->usb_serial);
+	RETURN_STRING(port->usb_serial);
 }
 
-char *sp_get_port_bluetooth_address(const struct sp_port *port)
+SP_API char *sp_get_port_bluetooth_address(const struct sp_port *port)
 {
 	TRACE("%p", port);
 
@@ -1090,10 +224,11 @@ char *sp_get_port_bluetooth_address(const struct sp_port *port)
 	    || !port->bluetooth_address)
 		return NULL;
 
-	RETURN_VALUE("%s", port->bluetooth_address);
+	RETURN_STRING(port->bluetooth_address);
 }
 
-enum sp_return sp_get_port_handle(const struct sp_port *port, void *result_ptr)
+SP_API enum sp_return sp_get_port_handle(const struct sp_port *port,
+                                         void *result_ptr)
 {
 	TRACE("%p, %p", port, result_ptr);
 
@@ -1111,7 +246,8 @@ enum sp_return sp_get_port_handle(const struct sp_port *port, void *result_ptr)
 	RETURN_OK();
 }
 
-enum sp_return sp_copy_port(const struct sp_port *port, struct sp_port **copy_ptr)
+SP_API enum sp_return sp_copy_port(const struct sp_port *port,
+                                   struct sp_port **copy_ptr)
 {
 	TRACE("%p, %p", port, copy_ptr);
 
@@ -1128,10 +264,10 @@ enum sp_return sp_copy_port(const struct sp_port *port, struct sp_port **copy_pt
 
 	DEBUG("Copying port structure");
 
-	RETURN_VALUE("%p", sp_get_port_by_name(port->name, copy_ptr));
+	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)
 {
 	TRACE("%p", port);
 
@@ -1164,7 +300,8 @@ void sp_free_port(struct sp_port *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;
@@ -1183,209 +320,42 @@ 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_ERR_SUPP;
+	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 **))))
+	if (!(list = malloc(sizeof(struct sp_port *))))
 		RETURN_ERROR(SP_ERR_MEM, "Port list malloc failed");
 
 	list[0] = NULL;
 
-#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;
-
-	ret = SP_OK;
-
-	DEBUG("Opening registry key");
-	if (RegOpenKeyEx(HKEY_LOCAL_MACHINE, _T("HARDWARE\\DEVICEMAP\\SERIALCOMM"),
-			0, KEY_QUERY_VALUE, &key) != ERROR_SUCCESS) {
-		SET_FAIL(ret, "RegOpenKeyEx() failed");
-		goto out_done;
-	}
-	DEBUG("Querying registry key value and data sizes");
-	if (RegQueryInfoKey(key, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
-				&max_value_len, &max_data_size, NULL, NULL) != ERROR_SUCCESS) {
-		SET_FAIL(ret, "RegQueryInfoKey() failed");
-		goto out_close;
-	}
-	max_data_len = max_data_size / sizeof(TCHAR);
-	if (!(value = malloc((max_value_len + 1) * sizeof(TCHAR)))) {
-		SET_ERROR(ret, SP_ERR_MEM, "registry value malloc failed");
-		goto out_close;
-	}
-	if (!(data = malloc((max_data_len + 1) * sizeof(TCHAR)))) {
-		SET_ERROR(ret, SP_ERR_MEM, "registry data malloc failed");
-		goto out_free_value;
-	}
-	DEBUG("Iterating over values");
-	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);
-#else
-		name_len = data_len + 1;
-#endif
-		if (!(name = malloc(name_len))) {
-			SET_ERROR(ret, SP_ERR_MEM, "registry port name malloc failed");
-			goto out;
-		}
-#ifdef UNICODE
-		WideCharToMultiByte(CP_ACP, 0, data, -1, name, name_len, NULL, NULL);
-#else
-		strcpy(name, data);
-#endif
-		if (type == REG_SZ) {
-			DEBUG("Found port %s", name);
-			if (!(list = list_append(list, name))) {
-				SET_ERROR(ret, SP_ERR_MEM, "list append failed");
-				goto out;
-			}
-		}
-		index++;
-	}
-out:
-	free(data);
-out_free_value:
-	free(value);
-out_close:
-	RegCloseKey(key);
-out_done:
-#endif
-#ifdef __APPLE__
-	CFMutableDictionaryRef classes;
-	io_iterator_t iter;
-	char path[PATH_MAX];
-	io_object_t port;
-	CFTypeRef cf_path;
-	Boolean result;
-
-	ret = SP_OK;
-
-	DEBUG("Creating matching dictionary");
-	if (!(classes = IOServiceMatching(kIOSerialBSDServiceValue))) {
-		SET_FAIL(ret, "IOServiceMatching() failed");
-		goto out_done;
-	}
-
-	DEBUG("Getting matching services");
-	if (IOServiceGetMatchingServices(kIOMasterPortDefault, classes,
-	                                 &iter) != KERN_SUCCESS) {
-		SET_FAIL(ret, "IOServiceGetMatchingServices() failed");
-		goto out_done;
-	}
-
-	DEBUG("Iterating over results");
-	while ((port = IOIteratorNext(iter))) {
-		cf_path = IORegistryEntryCreateCFProperty(port,
-				CFSTR(kIOCalloutDeviceKey), kCFAllocatorDefault, 0);
-		if (cf_path) {
-			result = CFStringGetCString(cf_path, path, sizeof(path),
-			                            kCFStringEncodingASCII);
-			CFRelease(cf_path);
-			if (result) {
-				DEBUG("Found port %s", path);
-				if (!(list = list_append(list, path))) {
-					SET_ERROR(ret, SP_ERR_MEM, "list append failed");
-					IOObjectRelease(port);
-					goto out;
-				}
-			}
-		}
-		IOObjectRelease(port);
-	}
-out:
-	IOObjectRelease(iter);
-out_done:
-#endif
-#ifdef __linux__
-	char name[PATH_MAX], target[PATH_MAX];
-	struct dirent entry, *result;
-	struct serial_struct serial_info;
-	int len, fd, ioctl_result;
-	DIR *dir;
-
-	ret = SP_OK;
-
-	DEBUG("Enumerating tty devices");
-	if (!(dir = opendir("/sys/class/tty")))
-		RETURN_FAIL("could not open /sys/class/tty");
-
-	DEBUG("Iterating over results");
-	while (!readdir_r(dir, &entry, &result) && result) {
-		len = readlinkat(dirfd(dir), entry.d_name, target, sizeof(target));
-		if (len <= 0 || len >= (int) sizeof(target)-1)
-			continue;
-		target[len] = 0;
-		if (strstr(target, "virtual"))
-			continue;
-		snprintf(name, sizeof(name), "/dev/%s", entry.d_name);
-		DEBUG("Found device %s", name);
-		if (strstr(target, "serial8250")) {
-			/* 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. */
-			DEBUG("serial8250 device, attempting to open");
-			if ((fd = open(name, O_RDWR | O_NONBLOCK | O_NOCTTY)) < 0) {
-				DEBUG("open failed, skipping");
-				continue;
-			}
-			ioctl_result = ioctl(fd, TIOCGSERIAL, &serial_info);
-			close(fd);
-			if (ioctl_result != 0) {
-				DEBUG("ioctl failed, skipping");
-				continue;
-			}
-			if (serial_info.type == PORT_UNKNOWN) {
-				DEBUG("port type is unknown, skipping");
-				continue;
-			}
-		}
-		DEBUG("Found port %s", name);
-		list = list_append(list, name);
-		if (!list) {
-			SET_ERROR(ret, SP_ERR_MEM, "list append failed");
-			break;
-		}
-	}
-	closedir(dir);
-#endif
+	ret = list_ports(&list);
 
-	switch (ret) {
-	case SP_OK:
+	if (ret == SP_OK) {
 		*list_ptr = list;
-		RETURN_OK();
-	case SP_ERR_SUPP:
-		DEBUG_ERROR(SP_ERR_SUPP, "Enumeration not supported on this platform");
-	default:
-		if (list)
-			sp_free_port_list(list);
+	} else {
+		sp_free_port_list(list);
 		*list_ptr = NULL;
-		return ret;
 	}
+
+	RETURN_CODEVAL(ret);
+#endif
 }
 
-void sp_free_port_list(struct sp_port **list)
+SP_API void sp_free_port_list(struct sp_port **list)
 {
 	unsigned int i;
 
@@ -1406,9 +376,9 @@ void sp_free_port_list(struct sp_port **list)
 }
 
 #define CHECK_PORT() do { \
-	if (port == NULL) \
+	if (!port) \
 		RETURN_ERROR(SP_ERR_ARG, "Null port"); \
-	if (port->name == NULL) \
+	if (!port->name) \
 		RETURN_ERROR(SP_ERR_ARG, "Null port name"); \
 } while (0)
 #ifdef _WIN32
@@ -1427,7 +397,44 @@ void sp_free_port_list(struct sp_port **list)
 	CHECK_PORT_HANDLE(); \
 } while (0)
 
-enum sp_return sp_open(struct sp_port *port, enum sp_mode flags)
+#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 (!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;
@@ -1437,10 +444,10 @@ enum sp_return sp_open(struct sp_port *port, enum sp_mode flags)
 
 	CHECK_PORT();
 
-	if (flags > (SP_MODE_READ | SP_MODE_WRITE))
+	if (flags > SP_MODE_READ_WRITE)
 		RETURN_ERROR(SP_ERR_ARG, "Invalid flags");
 
-	DEBUG("Opening port %s", port->name);
+	DEBUG_FMT("Opening port %s", port->name);
 
 #ifdef _WIN32
 	DWORD desired_access = 0, flags_and_attributes = 0, errors;
@@ -1465,7 +472,7 @@ enum sp_return sp_open(struct sp_port *port, enum sp_mode flags)
 	free(escaped_port_name);
 
 	if (port->hdl == INVALID_HANDLE_VALUE)
-		RETURN_FAIL("port CreateFile() failed");
+		RETURN_FAIL("Port CreateFile() failed");
 
 	/* All timeouts initially disabled. */
 	port->timeouts.ReadIntervalTimeout = 0;
@@ -1500,21 +507,20 @@ enum sp_return sp_open(struct sp_port *port, enum sp_mode flags)
 		RETURN_FAIL("SetCommMask() failed");
 	}
 
-	/* Start background operation for RX and error events. */
-	if (WaitCommEvent(port->hdl, &port->events, &port->wait_ovl) == 0) {
-		if (GetLastError() != ERROR_IO_PENDING) {
-			sp_close(port);
-			RETURN_FAIL("WaitCommEvent() failed");
-		}
-	}
-
 	port->writing = FALSE;
+	port->wait_running = FALSE;
+
+	ret = restart_wait(port);
 
+	if (ret < 0) {
+		sp_close(port);
+		RETURN_CODEVAL(ret);
+	}
 #else
 	int flags_local = O_NONBLOCK | O_NOCTTY;
 
 	/* Map 'flags' to the OS-specific settings. */
-	if (flags & (SP_MODE_READ | SP_MODE_WRITE))
+	if ((flags & SP_MODE_READ_WRITE) == SP_MODE_READ_WRITE)
 		flags_local |= O_RDWR;
 	else if (flags & SP_MODE_READ)
 		flags_local |= O_RDONLY;
@@ -1538,7 +544,7 @@ enum sp_return sp_open(struct sp_port *port, enum sp_mode flags)
 	data.dcb.fDsrSensitivity = FALSE;
 	data.dcb.fErrorChar = FALSE;
 	data.dcb.fNull = FALSE;
-	data.dcb.fAbortOnError = TRUE;
+	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);
@@ -1593,18 +599,18 @@ enum sp_return sp_open(struct sp_port *port, enum sp_mode flags)
 	RETURN_OK();
 }
 
-enum sp_return sp_close(struct sp_port *port)
+SP_API enum sp_return sp_close(struct sp_port *port)
 {
 	TRACE("%p", port);
 
 	CHECK_OPEN_PORT();
 
-	DEBUG("Closing port %s", port->name);
+	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");
+		RETURN_FAIL("Port CloseHandle() failed");
 	port->hdl = INVALID_HANDLE_VALUE;
 
 	/* Close event handles for overlapped structures. */
@@ -1627,7 +633,7 @@ enum sp_return sp_close(struct sp_port *port)
 	RETURN_OK();
 }
 
-enum sp_return sp_flush(struct sp_port *port, enum sp_buffer buffers)
+SP_API enum sp_return sp_flush(struct sp_port *port, enum sp_buffer buffers)
 {
 	TRACE("%p, 0x%x", port, buffers);
 
@@ -1638,7 +644,8 @@ enum sp_return sp_flush(struct sp_port *port, enum sp_buffer buffers)
 
 	const char *buffer_names[] = {"no", "input", "output", "both"};
 
-	DEBUG("Flushing %s buffers on port %s", buffer_names[buffers], port->name);
+	DEBUG_FMT("Flushing %s buffers on port %s",
+		buffer_names[buffers], port->name);
 
 #ifdef _WIN32
 	DWORD flags = 0;
@@ -1650,13 +657,16 @@ enum sp_return sp_flush(struct sp_port *port, enum sp_buffer buffers)
 	/* 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
 	int flags = 0;
-	if (buffers & SP_BUF_BOTH)
+	if (buffers == SP_BUF_BOTH)
 		flags = TCIOFLUSH;
-	else if (buffers & SP_BUF_INPUT)
+	else if (buffers == SP_BUF_INPUT)
 		flags = TCIFLUSH;
-	else if (buffers & SP_BUF_OUTPUT)
+	else if (buffers == SP_BUF_OUTPUT)
 		flags = TCOFLUSH;
 
 	/* Returns 0 upon success, -1 upon failure. */
@@ -1666,13 +676,13 @@ enum sp_return sp_flush(struct sp_port *port, enum sp_buffer buffers)
 	RETURN_OK();
 }
 
-enum sp_return sp_drain(struct sp_port *port)
+SP_API enum sp_return sp_drain(struct sp_port *port)
 {
 	TRACE("%p", port);
 
 	CHECK_OPEN_PORT();
 
-	DEBUG("Draining port %s", port->name);
+	DEBUG_FMT("Draining port %s", port->name);
 
 #ifdef _WIN32
 	/* Returns non-zero upon success, 0 upon failure. */
@@ -1702,7 +712,8 @@ enum sp_return sp_drain(struct sp_port *port)
 #endif
 }
 
-enum sp_return sp_blocking_write(struct sp_port *port, const void *buf, size_t count, unsigned int timeout)
+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);
 
@@ -1712,12 +723,14 @@ enum sp_return sp_blocking_write(struct sp_port *port, const void *buf, size_t c
 		RETURN_ERROR(SP_ERR_ARG, "Null buffer");
 
 	if (timeout)
-		DEBUG("Writing %d bytes to port %s, timeout %d ms", count, port->name, timeout);
+		DEBUG_FMT("Writing %d bytes to port %s, timeout %d ms",
+			count, port->name, timeout);
 	else
-		DEBUG("Writing %d bytes to port %s, no timeout", count, port->name);
+		DEBUG_FMT("Writing %d bytes to port %s, no timeout",
+			count, port->name);
 
 	if (count == 0)
-		RETURN_VALUE("0", 0);
+		RETURN_INT(0);
 
 #ifdef _WIN32
 	DWORD bytes_written = 0;
@@ -1743,14 +756,14 @@ enum sp_return sp_blocking_write(struct sp_port *port, const void *buf, size_t c
 		if (GetLastError() == ERROR_IO_PENDING) {
 			DEBUG("Waiting for write to complete");
 			GetOverlappedResult(port->hdl, &port->write_ovl, &bytes_written, TRUE);
-			DEBUG("Write completed, %d/%d bytes written", bytes_written, count);
-			RETURN_VALUE("%d", bytes_written);
+			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_VALUE("%d", count);
+		RETURN_INT(count);
 	}
 #else
 	size_t bytes_written = 0;
@@ -1770,16 +783,15 @@ enum sp_return sp_blocking_write(struct sp_port *port, const void *buf, size_t c
 	}
 
 	/* Loop until we have written the requested number of bytes. */
-	while (bytes_written < count)
-	{
+	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_VALUE("%d", bytes_written);
+				DEBUG("Write timed out");
+				RETURN_INT(bytes_written);
 			}
 			timersub(&end, &now, &delta);
 		}
@@ -1792,8 +804,8 @@ enum sp_return sp_blocking_write(struct sp_port *port, const void *buf, size_t c
 				RETURN_FAIL("select() failed");
 			}
 		} else if (result == 0) {
-			DEBUG("write timed out");
-			RETURN_VALUE("%d", bytes_written);
+			DEBUG("Write timed out");
+			RETURN_INT(bytes_written);
 		}
 
 		/* Do write. */
@@ -1812,11 +824,12 @@ enum sp_return sp_blocking_write(struct sp_port *port, const void *buf, size_t c
 		ptr += result;
 	}
 
-	RETURN_VALUE("%d", bytes_written);
+	RETURN_INT(bytes_written);
 #endif
 }
 
-enum sp_return sp_nonblocking_write(struct sp_port *port, const void *buf, size_t count)
+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);
 
@@ -1825,10 +838,10 @@ enum sp_return sp_nonblocking_write(struct sp_port *port, const void *buf, size_
 	if (!buf)
 		RETURN_ERROR(SP_ERR_ARG, "Null buffer");
 
-	DEBUG("Writing up to %d bytes to port %s", count, port->name);
+	DEBUG_FMT("Writing up to %d bytes to port %s", count, port->name);
 
 	if (count == 0)
-		RETURN_VALUE("0", 0);
+		RETURN_INT(0);
 
 #ifdef _WIN32
 	DWORD written = 0;
@@ -1842,7 +855,7 @@ enum sp_return sp_nonblocking_write(struct sp_port *port, const void *buf, size_
 		} else {
 			DEBUG("Previous write not complete");
 			/* Can't take a new write until the previous one finishes. */
-			RETURN_VALUE("0", 0);
+			RETURN_INT(0);
 		}
 	}
 
@@ -1851,10 +864,11 @@ enum sp_return sp_nonblocking_write(struct sp_port *port, const void *buf, size_
 	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)
-	{
+	/*
+	 * 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++;
 
@@ -1869,7 +883,7 @@ enum sp_return sp_nonblocking_write(struct sp_port *port, const void *buf, size_
 				} else {
 					DEBUG("Asynchronous write running");
 					port->writing = 1;
-					RETURN_VALUE("%d", ++written);
+					RETURN_INT(++written);
 				}
 			} else {
 				/* Actual failure of some kind. */
@@ -1883,7 +897,7 @@ enum sp_return sp_nonblocking_write(struct sp_port *port, const void *buf, size_
 
 	DEBUG("All bytes written immediately");
 
-	RETURN_VALUE("%d", written);
+	RETURN_INT(written);
 #else
 	/* Returns the number of bytes written, or -1 upon failure. */
 	ssize_t written = write(port->fd, buf, count);
@@ -1891,11 +905,12 @@ enum sp_return sp_nonblocking_write(struct sp_port *port, const void *buf, size_
 	if (written < 0)
 		RETURN_FAIL("write() failed");
 	else
-		RETURN_VALUE("%d", written);
+		RETURN_INT(written);
 #endif
 }
 
-enum sp_return sp_blocking_read(struct sp_port *port, void *buf, size_t count, unsigned int timeout)
+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);
 
@@ -1905,15 +920,19 @@ enum sp_return sp_blocking_read(struct sp_port *port, void *buf, size_t count, u
 		RETURN_ERROR(SP_ERR_ARG, "Null buffer");
 
 	if (timeout)
-		DEBUG("Reading %d bytes from port %s, timeout %d ms", count, port->name, timeout);
+		DEBUG_FMT("Reading %d bytes from port %s, timeout %d ms",
+			count, port->name, timeout);
 	else
-		DEBUG("Reading %d bytes from port %s, no timeout", count, port->name);
+		DEBUG_FMT("Reading %d bytes from port %s, no timeout",
+			count, port->name);
 
 	if (count == 0)
-		RETURN_VALUE("0", 0);
+		RETURN_INT(0);
 
 #ifdef _WIN32
 	DWORD bytes_read = 0;
+	DWORD bytes_remaining;
+	int ret;
 
 	/* Set timeout. */
 	port->timeouts.ReadIntervalTimeout = 0;
@@ -1926,7 +945,7 @@ enum sp_return sp_blocking_read(struct sp_port *port, void *buf, size_t count, u
 		if (GetLastError() == ERROR_IO_PENDING) {
 			DEBUG("Waiting for read to complete");
 			GetOverlappedResult(port->hdl, &port->read_ovl, &bytes_read, TRUE);
-			DEBUG("Read completed, %d/%d bytes read", bytes_read, count);
+			DEBUG_FMT("Read completed, %d/%d bytes read", bytes_read, count);
 		} else {
 			RETURN_FAIL("ReadFile() failed");
 		}
@@ -1935,13 +954,18 @@ enum sp_return sp_blocking_read(struct sp_port *port, void *buf, size_t count, u
 		bytes_read = count;
 	}
 
-	/* Start background operation for subsequent events. */
-	if (WaitCommEvent(port->hdl, &port->events, &port->wait_ovl) == 0) {
-		if (GetLastError() != ERROR_IO_PENDING)
-			RETURN_FAIL("WaitCommEvent() failed");
-	}
+	ret = sp_input_waiting(port);
 
-	RETURN_VALUE("%d", bytes_read);
+	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;
@@ -1961,8 +985,7 @@ enum sp_return sp_blocking_read(struct sp_port *port, void *buf, size_t count, u
 	}
 
 	/* Loop until we have the requested number of bytes. */
-	while (bytes_read < count)
-	{
+	while (bytes_read < count) {
 		/* Wait until data is available. */
 		FD_ZERO(&fds);
 		FD_SET(port->fd, &fds);
@@ -1970,7 +993,7 @@ enum sp_return sp_blocking_read(struct sp_port *port, void *buf, size_t count, u
 			gettimeofday(&now, NULL);
 			if (timercmp(&now, &end, >))
 				/* Timeout has expired. */
-				RETURN_VALUE("%d", bytes_read);
+				RETURN_INT(bytes_read);
 			timersub(&end, &now, &delta);
 		}
 		result = select(port->fd + 1, &fds, NULL, NULL, timeout ? &delta : NULL);
@@ -1982,8 +1005,8 @@ enum sp_return sp_blocking_read(struct sp_port *port, void *buf, size_t count, u
 				RETURN_FAIL("select() failed");
 			}
 		} else if (result == 0) {
-			DEBUG("read timed out");
-			RETURN_VALUE("%d", bytes_read);
+			DEBUG("Read timed out");
+			RETURN_INT(bytes_read);
 		}
 
 		/* Do read. */
@@ -2002,11 +1025,12 @@ enum sp_return sp_blocking_read(struct sp_port *port, void *buf, size_t count, u
 		ptr += result;
 	}
 
-	RETURN_VALUE("%d", bytes_read);
+	RETURN_INT(bytes_read);
 #endif
 }
 
-enum sp_return sp_nonblocking_read(struct sp_port *port, void *buf, size_t count)
+SP_API enum sp_return sp_nonblocking_read(struct sp_port *port, void *buf,
+                                          size_t count)
 {
 	TRACE("%p, %p, %d", port, buf, count);
 
@@ -2015,10 +1039,12 @@ enum sp_return sp_nonblocking_read(struct sp_port *port, void *buf, size_t count
 	if (!buf)
 		RETURN_ERROR(SP_ERR_ARG, "Null buffer");
 
-	DEBUG("Reading up to %d bytes from port %s", count, port->name);
+	DEBUG_FMT("Reading up to %d bytes from port %s", count, port->name);
 
 #ifdef _WIN32
 	DWORD bytes_read;
+	DWORD bytes_remaining;
+	int ret;
 
 	/* Set timeout. */
 	port->timeouts.ReadIntervalTimeout = MAXDWORD;
@@ -2034,15 +1060,18 @@ enum sp_return sp_nonblocking_read(struct sp_port *port, void *buf, size_t count
 	if (GetOverlappedResult(port->hdl, &port->read_ovl, &bytes_read, TRUE) == 0)
 		RETURN_FAIL("GetOverlappedResult() failed");
 
-	if (bytes_read > 0) {
-		/* Start background operation for subsequent events. */
-		if (WaitCommEvent(port->hdl, &port->events, &port->wait_ovl) == 0) {
-			if (GetLastError() != ERROR_IO_PENDING)
-				RETURN_FAIL("WaitCommEvent() 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_VALUE("%d", bytes_read);
+	RETURN_INT(bytes_read);
 #else
 	ssize_t bytes_read;
 
@@ -2055,17 +1084,17 @@ enum sp_return sp_nonblocking_read(struct sp_port *port, void *buf, size_t count
 			/* This is an actual failure. */
 			RETURN_FAIL("read() failed");
 	}
-	RETURN_VALUE("%d", bytes_read);
+	RETURN_INT(bytes_read);
 #endif
 }
 
-enum sp_return sp_input_waiting(struct sp_port *port)
+SP_API enum sp_return sp_input_waiting(struct sp_port *port)
 {
 	TRACE("%p", port);
 
 	CHECK_OPEN_PORT();
 
-	DEBUG("Checking input bytes waiting on port %s", port->name);
+	DEBUG_FMT("Checking input bytes waiting on port %s", port->name);
 
 #ifdef _WIN32
 	DWORD errors;
@@ -2073,22 +1102,22 @@ enum sp_return sp_input_waiting(struct sp_port *port)
 
 	if (ClearCommError(port->hdl, &errors, &comstat) == 0)
 		RETURN_FAIL("ClearCommError() failed");
-	RETURN_VALUE("%d", comstat.cbInQue);
+	RETURN_INT(comstat.cbInQue);
 #else
 	int bytes_waiting;
 	if (ioctl(port->fd, TIOCINQ, &bytes_waiting) < 0)
 		RETURN_FAIL("TIOCINQ ioctl failed");
-	RETURN_VALUE("%d", bytes_waiting);
+	RETURN_INT(bytes_waiting);
 #endif
 }
 
-enum sp_return sp_output_waiting(struct sp_port *port)
+SP_API enum sp_return sp_output_waiting(struct sp_port *port)
 {
 	TRACE("%p", port);
 
 	CHECK_OPEN_PORT();
 
-	DEBUG("Checking output bytes waiting on port %s", port->name);
+	DEBUG_FMT("Checking output bytes waiting on port %s", port->name);
 
 #ifdef _WIN32
 	DWORD errors;
@@ -2096,16 +1125,16 @@ enum sp_return sp_output_waiting(struct sp_port *port)
 
 	if (ClearCommError(port->hdl, &errors, &comstat) == 0)
 		RETURN_FAIL("ClearCommError() failed");
-	RETURN_VALUE("%d", comstat.cbOutQue);
+	RETURN_INT(comstat.cbOutQue);
 #else
 	int bytes_waiting;
 	if (ioctl(port->fd, TIOCOUTQ, &bytes_waiting) < 0)
 		RETURN_FAIL("TIOCOUTQ ioctl failed");
-	RETURN_VALUE("%d", bytes_waiting);
+	RETURN_INT(bytes_waiting);
 #endif
 }
 
-enum sp_return sp_new_event_set(struct sp_event_set **result_ptr)
+SP_API enum sp_return sp_new_event_set(struct sp_event_set **result_ptr)
 {
 	struct sp_event_set *result;
 
@@ -2136,13 +1165,14 @@ static enum sp_return add_handle(struct sp_event_set *event_set,
 
 	if (!(new_handles = realloc(event_set->handles,
 			sizeof(event_handle) * (event_set->count + 1))))
-		RETURN_ERROR(SP_ERR_MEM, "handle array realloc() failed");
+		RETURN_ERROR(SP_ERR_MEM, "Handle array realloc() failed");
+
+	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");
+		RETURN_ERROR(SP_ERR_MEM, "Mask array realloc() failed");
 
-	event_set->handles = new_handles;
 	event_set->masks = new_masks;
 
 	((event_handle *) event_set->handles)[event_set->count] = handle;
@@ -2153,7 +1183,7 @@ static enum sp_return add_handle(struct sp_event_set *event_set,
 	RETURN_OK();
 }
 
-enum sp_return sp_add_port_events(struct sp_event_set *event_set,
+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);
@@ -2183,7 +1213,7 @@ enum sp_return sp_add_port_events(struct sp_event_set *event_set,
 	RETURN_OK();
 }
 
-void sp_free_event_set(struct sp_event_set *event_set)
+SP_API void sp_free_event_set(struct sp_event_set *event_set)
 {
 	TRACE("%p", event_set);
 
@@ -2204,7 +1234,8 @@ void sp_free_event_set(struct sp_event_set *event_set)
 	RETURN();
 }
 
-enum sp_return sp_wait(struct sp_event_set *event_set, unsigned int timeout)
+SP_API enum sp_return sp_wait(struct sp_event_set *event_set,
+                              unsigned int timeout)
 {
 	TRACE("%p, %d", event_set, timeout);
 
@@ -2249,12 +1280,11 @@ enum sp_return sp_wait(struct sp_event_set *event_set, unsigned int timeout)
 	}
 
 	/* Loop until an event occurs. */
-	while (1)
-	{
+	while (1) {
 		if (timeout) {
 			gettimeofday(&now, NULL);
 			if (timercmp(&now, &end, >)) {
-				DEBUG("wait timed out");
+				DEBUG("Wait timed out");
 				break;
 			}
 			timersub(&end, &now, &delta);
@@ -2299,7 +1329,7 @@ static enum sp_return get_baudrate(int fd, int *baudrate)
 
 	if (ioctl(fd, get_termios_get_ioctl(), data) < 0) {
 		free(data);
-		RETURN_FAIL("getting termios failed");
+		RETURN_FAIL("Getting termios failed");
 	}
 
 	*baudrate = get_termios_speed(data);
@@ -2322,7 +1352,7 @@ static enum sp_return set_baudrate(int fd, int baudrate)
 
 	if (ioctl(fd, get_termios_get_ioctl(), data) < 0) {
 		free(data);
-		RETURN_FAIL("getting termios failed");
+		RETURN_FAIL("Getting termios failed");
 	}
 
 	DEBUG("Setting baud rate");
@@ -2331,7 +1361,7 @@ static enum sp_return set_baudrate(int fd, int baudrate)
 
 	if (ioctl(fd, get_termios_set_ioctl(), data) < 0) {
 		free(data);
-		RETURN_FAIL("setting termios failed");
+		RETURN_FAIL("Setting termios failed");
 	}
 
 	free(data);
@@ -2354,7 +1384,7 @@ static enum sp_return get_flow(int fd, struct port_data *data)
 
 	if (ioctl(fd, TCGETX, termx) < 0) {
 		free(termx);
-		RETURN_FAIL("getting termiox failed");
+		RETURN_FAIL("Getting termiox failed");
 	}
 
 	get_termiox_flow(termx, &data->rts_flow, &data->cts_flow,
@@ -2378,7 +1408,7 @@ static enum sp_return set_flow(int fd, struct port_data *data)
 
 	if (ioctl(fd, TCGETX, termx) < 0) {
 		free(termx);
-		RETURN_FAIL("getting termiox failed");
+		RETURN_FAIL("Getting termiox failed");
 	}
 
 	DEBUG("Setting advanced flow control");
@@ -2388,7 +1418,7 @@ static enum sp_return set_flow(int fd, struct port_data *data)
 
 	if (ioctl(fd, TCSETX, termx) < 0) {
 		free(termx);
-		RETURN_FAIL("setting termiox failed");
+		RETURN_FAIL("Setting termiox failed");
 	}
 
 	free(termx);
@@ -2404,7 +1434,7 @@ static enum sp_return get_config(struct sp_port *port, struct port_data *data,
 
 	TRACE("%p, %p, %p", port, data, config);
 
-	DEBUG("Getting configuration for port %s", port->name);
+	DEBUG_FMT("Getting configuration for port %s", port->name);
 
 #ifdef _WIN32
 	if (!GetCommState(port->hdl, &data->dcb))
@@ -2621,7 +1651,7 @@ static enum sp_return set_config(struct sp_port *port, struct port_data *data,
 
 	TRACE("%p, %p, %p", port, data, config);
 
-	DEBUG("Setting configuration for port %s", port->name);
+	DEBUG_FMT("Setting configuration for port %s", port->name);
 
 #ifdef _WIN32
 	if (config->baudrate >= 0) {
@@ -2972,8 +2002,10 @@ static enum sp_return set_config(struct sp_port *port, struct port_data *data,
 	if (baud_nonstd != B0) {
 		if (ioctl(port->fd, IOSSIOSPEED, &baud_nonstd) == -1)
 			RETURN_FAIL("IOSSIOSPEED ioctl failed");
-		/* Set baud rates in data->term to correct, but incompatible
-		 * with tcsetattr() value, same as delivered by tcgetattr(). */
+		/*
+		 * 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_FAIL("cfsetspeed() failed");
 	}
@@ -2993,7 +2025,7 @@ static enum sp_return set_config(struct sp_port *port, struct port_data *data,
 	RETURN_OK();
 }
 
-enum sp_return sp_new_config(struct sp_port_config **config_ptr)
+SP_API enum sp_return sp_new_config(struct sp_port_config **config_ptr)
 {
 	struct sp_port_config *config;
 
@@ -3005,7 +2037,7 @@ enum sp_return sp_new_config(struct sp_port_config **config_ptr)
 	*config_ptr = NULL;
 
 	if (!(config = malloc(sizeof(struct sp_port_config))))
-		RETURN_ERROR(SP_ERR_MEM, "config malloc failed");
+		RETURN_ERROR(SP_ERR_MEM, "Config malloc failed");
 
 	config->baudrate = -1;
 	config->bits = -1;
@@ -3021,7 +2053,7 @@ enum sp_return sp_new_config(struct sp_port_config **config_ptr)
 	RETURN_OK();
 }
 
-void sp_free_config(struct sp_port_config *config)
+SP_API void sp_free_config(struct sp_port_config *config)
 {
 	TRACE("%p", config);
 
@@ -3033,7 +2065,8 @@ void sp_free_config(struct sp_port_config *config)
 	RETURN();
 }
 
-enum sp_return sp_get_config(struct sp_port *port, struct sp_port_config *config)
+SP_API enum sp_return sp_get_config(struct sp_port *port,
+                                    struct sp_port_config *config)
 {
 	struct port_data data;
 
@@ -3049,7 +2082,8 @@ enum sp_return sp_get_config(struct sp_port *port, struct sp_port_config *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;
@@ -3068,7 +2102,7 @@ enum sp_return sp_set_config(struct sp_port *port, const struct sp_port_config *
 }
 
 #define CREATE_ACCESSORS(x, type) \
-enum sp_return sp_set_##x(struct sp_port *port, type x) { \
+SP_API enum sp_return sp_set_##x(struct sp_port *port, type x) { \
 	struct port_data data; \
 	struct sp_port_config config; \
 	TRACE("%p, %d", port, x); \
@@ -3078,14 +2112,16 @@ enum sp_return sp_set_##x(struct sp_port *port, type x) { \
 	TRY(set_config(port, &data, &config)); \
 	RETURN_OK(); \
 } \
-enum sp_return sp_get_config_##x(const struct sp_port_config *config, type *x) { \
+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(); \
 } \
-enum sp_return sp_set_config_##x(struct sp_port_config *config, type x) { \
+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"); \
@@ -3103,7 +2139,8 @@ CREATE_ACCESSORS(dtr, enum sp_dtr)
 CREATE_ACCESSORS(dsr, enum sp_dsr)
 CREATE_ACCESSORS(xon_xoff, enum sp_xonxoff)
 
-enum sp_return sp_set_config_flowcontrol(struct sp_port_config *config, enum sp_flowcontrol flowcontrol)
+SP_API enum sp_return sp_set_config_flowcontrol(struct sp_port_config *config,
+                                                enum sp_flowcontrol flowcontrol)
 {
 	if (!config)
 		RETURN_ERROR(SP_ERR_ARG, "Null configuration");
@@ -3137,7 +2174,8 @@ enum sp_return sp_set_config_flowcontrol(struct sp_port_config *config, enum sp_
 	RETURN_OK();
 }
 
-enum sp_return sp_set_flowcontrol(struct sp_port *port, enum sp_flowcontrol flowcontrol)
+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;
@@ -3155,7 +2193,8 @@ enum sp_return sp_set_flowcontrol(struct sp_port *port, enum sp_flowcontrol flow
 	RETURN_OK();
 }
 
-enum sp_return sp_get_signals(struct sp_port *port, enum sp_signal *signals)
+SP_API enum sp_return sp_get_signals(struct sp_port *port,
+                                     enum sp_signal *signals)
 {
 	TRACE("%p, %p", port, signals);
 
@@ -3164,7 +2203,7 @@ enum sp_return sp_get_signals(struct sp_port *port, enum sp_signal *signals)
 	if (!signals)
 		RETURN_ERROR(SP_ERR_ARG, "Null result pointer");
 
-	DEBUG("Getting control signals for port %s", port->name);
+	DEBUG_FMT("Getting control signals for port %s", port->name);
 
 	*signals = 0;
 #ifdef _WIN32
@@ -3195,7 +2234,7 @@ enum sp_return sp_get_signals(struct sp_port *port, enum sp_signal *signals)
 	RETURN_OK();
 }
 
-enum sp_return sp_start_break(struct sp_port *port)
+SP_API enum sp_return sp_start_break(struct sp_port *port)
 {
 	TRACE("%p", port);
 
@@ -3211,7 +2250,7 @@ enum sp_return sp_start_break(struct sp_port *port)
 	RETURN_OK();
 }
 
-enum sp_return sp_end_break(struct sp_port *port)
+SP_API enum sp_return sp_end_break(struct sp_port *port)
 {
 	TRACE("%p", port);
 
@@ -3227,19 +2266,19 @@ enum sp_return sp_end_break(struct sp_port *port)
 	RETURN_OK();
 }
 
-int sp_last_error_code(void)
+SP_API int sp_last_error_code(void)
 {
-	TRACE("");
+	TRACE_VOID();
 #ifdef _WIN32
-	RETURN_VALUE("%d", GetLastError());
+	RETURN_INT(GetLastError());
 #else
-	RETURN_VALUE("%d", errno);
+	RETURN_INT(errno);
 #endif
 }
 
-char *sp_last_error_message(void)
+SP_API char *sp_last_error_message(void)
 {
-	TRACE("");
+	TRACE_VOID();
 
 #ifdef _WIN32
 	LPVOID message;
@@ -3255,13 +2294,13 @@ char *sp_last_error_message(void)
 		(LPTSTR) &message,
 		0, NULL );
 
-	RETURN_VALUE("%s", message);
+	RETURN_STRING(message);
 #else
-	RETURN_VALUE("%s", 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);
 
@@ -3274,7 +2313,7 @@ void sp_free_error_message(char *message)
 	RETURN();
 }
 
-void sp_set_debug_handler(void (*handler)(const char *format, ...))
+SP_API void sp_set_debug_handler(void (*handler)(const char *format, ...))
 {
 	TRACE("%p", handler);
 
@@ -3283,7 +2322,7 @@ void sp_set_debug_handler(void (*handler)(const char *format, ...))
 	RETURN();
 }
 
-void sp_default_debug_handler(const char *format, ...)
+SP_API void sp_default_debug_handler(const char *format, ...)
 {
 	va_list args;
 	va_start(args, format);
@@ -3294,42 +2333,42 @@ void sp_default_debug_handler(const char *format, ...)
 	va_end(args);
 }
 
-int sp_get_major_package_version(void)
+SP_API int sp_get_major_package_version(void)
 {
 	return SP_PACKAGE_VERSION_MAJOR;
 }
 
-int sp_get_minor_package_version(void)
+SP_API int sp_get_minor_package_version(void)
 {
 	return SP_PACKAGE_VERSION_MINOR;
 }
 
-int sp_get_micro_package_version(void)
+SP_API int sp_get_micro_package_version(void)
 {
 	return SP_PACKAGE_VERSION_MICRO;
 }
 
-const char *sp_get_package_version_string(void)
+SP_API const char *sp_get_package_version_string(void)
 {
 	return SP_PACKAGE_VERSION_STRING;
 }
 
-int sp_get_current_lib_version(void)
+SP_API int sp_get_current_lib_version(void)
 {
 	return SP_LIB_VERSION_CURRENT;
 }
 
-int sp_get_revision_lib_version(void)
+SP_API int sp_get_revision_lib_version(void)
 {
 	return SP_LIB_VERSION_REVISION;
 }
 
-int sp_get_age_lib_version(void)
+SP_API int sp_get_age_lib_version(void)
 {
 	return SP_LIB_VERSION_AGE;
 }
 
-const char *sp_get_lib_version_string(void)
+SP_API const char *sp_get_lib_version_string(void)
 {
 	return SP_LIB_VERSION_STRING;
 }