]> sigrok.org Git - libserialport.git/blobdiff - serialport.c
Add new APIs to get some USB descriptor details for USB serial ports.
[libserialport.git] / serialport.c
index 66149f34420f4c02a9c679b18a9c227f06ea6c9d..9ebc2da7f226324fa83ef0363620734a203b35eb 100644 (file)
@@ -4,6 +4,8 @@
  * Copyright (C) 2010-2012 Bert Vermeulen <bert@biot.com>
  * 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
 #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>
-#include <stdio.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 "libudev.h"
+#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"
 
-struct sp_port_data {
+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 rts;
-       int dtr;
+       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[] = {
+#ifdef _WIN32
+       /*
+        * The baudrates 50/75/134/150/200/1800/230400/460800 do not seem to
+        * have documented CBR_* macros.
+        */
+       BAUD(110), BAUD(300), BAUD(600), BAUD(1200), BAUD(2400), BAUD(4800),
+       BAUD(9600), BAUD(14400), BAUD(19200), BAUD(38400), BAUD(57600),
+       BAUD(115200), BAUD(128000), BAUD(256000),
+#else
+       BAUD(50), BAUD(75), BAUD(110), BAUD(134), BAUD(150), BAUD(200),
+       BAUD(300), BAUD(600), BAUD(1200), BAUD(1800), BAUD(2400), BAUD(4800),
+       BAUD(9600), BAUD(19200), BAUD(38400), BAUD(57600), BAUD(115200),
+       BAUD(230400),
+#if !defined(__APPLE__) && !defined(__OpenBSD__)
+       BAUD(460800),
+#endif
 #endif
 };
 
-int sp_get_port_by_name(const char *portname, struct sp_port **port_ptr)
+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)
+
+/* 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)
 {
        struct sp_port *port;
+       enum sp_return ret;
        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("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)))
-       {
+       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->hdl = INVALID_HANDLE_VALUE;
+#else
+       port->fd = -1;
+#endif
+
+       if ((ret = sp_get_port_details(port)) != SP_OK) {
+               sp_free_port(port);
+               return ret;
+       }
+
        *port_ptr = port;
 
-       return SP_OK;
+       RETURN_OK();
+}
+
+char *sp_get_port_name(const struct sp_port *port)
+{
+       TRACE("%p", port);
+
+       if (!port)
+               return NULL;
+
+       RETURN_VALUE("%s", port->name);
+}
+
+char *sp_get_port_description(struct sp_port *port)
+{
+       TRACE("%p", port);
+
+       if (!port || !port->description)
+               return NULL;
+
+       RETURN_VALUE("%s", port->description);
+}
+
+enum sp_transport sp_get_port_transport(struct sp_port *port)
+{
+       TRACE("%p", port);
+
+       if (!port)
+               RETURN_ERROR(SP_ERR_ARG, "Null port");
+
+       RETURN_VALUE("%d", port->transport);
+}
+
+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 (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)
+{
+       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 (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)
+{
+       TRACE("%p", port);
+
+       if (!port || port->transport != SP_TRANSPORT_USB || !port->usb_manufacturer)
+               return NULL;
+
+       RETURN_VALUE("%s", port->usb_manufacturer);
+}
+
+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);
+}
+
+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);
 }
 
-int sp_copy_port(const struct sp_port *port, struct sp_port **copy_ptr)
+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_VALUE("%s", port->bluetooth_address);
+}
+
+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();
+}
+
+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");
+
+       if (!port->name)
+               RETURN_ERROR(SP_ERR_ARG, "Null port name");
 
-       return sp_get_port_by_name(port->name, copy_ptr);
+       DEBUG("Copying port structure");
+
+       RETURN_VALUE("%p", sp_get_port_by_name(port->name, copy_ptr));
 }
 
 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 **sp_list_append(struct sp_port **list, const char *portname)
+static struct sp_port **list_append(struct sp_port **list, const char *portname)
 {
        void *tmp;
        unsigned int count;
@@ -130,13 +1183,20 @@ fail:
        return NULL;
 }
 
-int sp_list_ports(struct sp_port ***list_ptr)
+enum sp_return sp_list_ports(struct sp_port ***list_ptr)
 {
        struct sp_port **list;
-       int ret = SP_OK;
+       int ret = SP_ERR_SUPP;
+
+       TRACE("%p", list_ptr);
+
+       if (!list_ptr)
+               RETURN_ERROR(SP_ERR_ARG, "Null result pointer");
+
+       DEBUG("Enumerating ports");
 
        if (!(list = malloc(sizeof(struct sp_port **))))
-               return SP_ERR_MEM;
+               RETURN_ERROR(SP_ERR_MEM, "Port list malloc failed");
 
        list[0] = NULL;
 
@@ -149,29 +1209,30 @@ int sp_list_ports(struct sp_port ***list_ptr)
        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)
-       {
-               ret = SP_ERR_FAIL;
+                       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)
-       {
-               ret = SP_ERR_FAIL;
+                               &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))))
-       {
-               ret = SP_ERR_MEM;
+       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))))
-       {
-               ret = SP_ERR_MEM;
+       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,
@@ -181,13 +1242,12 @@ int sp_list_ports(struct sp_port ***list_ptr)
                data_len = data_size / sizeof(TCHAR);
                data[data_len] = '\0';
 #ifdef UNICODE
-               name_len = WideCharToMultiByte(CP_ACP, 0, data, -1, NULL, 0, NULL, NULL)
+               name_len = WideCharToMultiByte(CP_ACP, 0, data, -1, NULL, 0, NULL, NULL);
 #else
                name_len = data_len + 1;
 #endif
-               if (!(name = malloc(name_len)))
-               {
-                       ret = SP_ERR_MEM;
+               if (!(name = malloc(name_len))) {
+                       SET_ERROR(ret, SP_ERR_MEM, "registry port name malloc failed");
                        goto out;
                }
 #ifdef UNICODE
@@ -195,10 +1255,12 @@ int sp_list_ports(struct sp_port ***list_ptr)
 #else
                strcpy(name, data);
 #endif
-               if (type == REG_SZ && !(list = sp_list_append(list, name)))
-               {
-                       ret = SP_ERR_MEM;
-                       goto out;
+               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++;
        }
@@ -211,642 +1273,1974 @@ out_close:
 out_done:
 #endif
 #ifdef __APPLE__
-       mach_port_t master;
        CFMutableDictionaryRef classes;
        io_iterator_t iter;
-       char *path;
+       char path[PATH_MAX];
        io_object_t port;
        CFTypeRef cf_path;
        Boolean result;
 
-       if (IOMasterPort(MACH_PORT_NULL, &master) != KERN_SUCCESS)
-       {
-               ret = SP_ERR_FAIL;
-               goto out_done;
-       }
+       ret = SP_OK;
 
-       if (!(classes = IOServiceMatching(kIOSerialBSDServiceValue)))
-       {
-               ret = SP_ERR_FAIL;
+       DEBUG("Creating matching dictionary");
+       if (!(classes = IOServiceMatching(kIOSerialBSDServiceValue))) {
+               SET_FAIL(ret, "IOServiceMatching() failed");
                goto out_done;
        }
 
-       CFDictionarySetValue(classes,
-                       CFSTR(kIOSerialBSDTypeKey), CFSTR(kIOSerialBSDAllTypes));
-
-       if (IOServiceGetMatchingServices(master, classes, &iter) != KERN_SUCCESS)
-       {
-               ret = SP_ERR_FAIL;
+       DEBUG("Getting matching services");
+       if (IOServiceGetMatchingServices(kIOMasterPortDefault, classes,
+                                        &iter) != KERN_SUCCESS) {
+               SET_FAIL(ret, "IOServiceGetMatchingServices() failed");
                goto out_done;
        }
 
-       if (!(path = malloc(PATH_MAX)))
-       {
-               ret = SP_ERR_MEM;
-               goto out_release;
-       }
-
+       DEBUG("Iterating over results");
        while ((port = IOIteratorNext(iter))) {
                cf_path = IORegistryEntryCreateCFProperty(port,
                                CFSTR(kIOCalloutDeviceKey), kCFAllocatorDefault, 0);
                if (cf_path) {
-                       result = CFStringGetCString(cf_path,
-                                       path, PATH_MAX, kCFStringEncodingASCII);
+                       result = CFStringGetCString(cf_path, path, sizeof(path),
+                                                   kCFStringEncodingASCII);
                        CFRelease(cf_path);
-                       if (result && !(list = sp_list_append(list, path)))
-                       {
-                               ret = SP_ERR_MEM;
-                               IOObjectRelease(port);
-                               goto out;
+                       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:
-       free(path);
-out_release:
        IOObjectRelease(iter);
 out_done:
 #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;
+       char name[PATH_MAX], target[PATH_MAX];
+       struct dirent entry, *result;
        struct serial_struct serial_info;
+       int len, fd, ioctl_result;
+       DIR *dir;
 
-       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);
+       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;
-               }
-               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;
+               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)
-                               goto skip;
-                       if (serial_info.type == PORT_UNKNOWN)
-                               goto skip;
-               }
-               list = sp_list_append(list, name);
-skip:
-               udev_device_unref(ud_dev);
-               if (!list)
-               {
-                       ret = SP_ERR_MEM;
-                       goto out;
+                       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
+
+       switch (ret) {
+       case 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);
+               *list_ptr = NULL;
+               return ret;
+       }
+}
+
+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 == NULL) \
+               RETURN_ERROR(SP_ERR_ARG, "Null port"); \
+       if (port->name == NULL) \
+               RETURN_ERROR(SP_ERR_ARG, "Null port name"); \
+} while (0)
+#ifdef _WIN32
+#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)
+
+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 | SP_MODE_WRITE))
+               RETURN_ERROR(SP_ERR_ARG, "Invalid flags");
+
+       DEBUG("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");
+       }
+
+       /* 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;
+
+#else
+       int flags_local = O_NONBLOCK | O_NOCTTY;
+
+       /* Map 'flags' to the OS-specific settings. */
+       if (flags & (SP_MODE_READ | SP_MODE_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);
+       }
+
+       /* 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 = TRUE;
+#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);
+       }
+
+       RETURN_OK();
+}
+
+enum sp_return sp_close(struct sp_port *port)
+{
+       TRACE("%p", port);
+
+       CHECK_OPEN_PORT();
+
+       DEBUG("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
+       /* Returns 0 upon success, -1 upon failure. */
+       if (close(port->fd) == -1)
+               RETURN_FAIL("close() failed");
+       port->fd = -1;
+#endif
+
+       RETURN_OK();
+}
+
+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("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");
+#else
+       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
+       RETURN_OK();
+}
+
+enum sp_return sp_drain(struct sp_port *port)
+{
+       TRACE("%p", port);
+
+       CHECK_OPEN_PORT();
+
+       DEBUG("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();
+               }
+       }
+#endif
+}
+
+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("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);
+
+       if (count == 0)
+               RETURN_VALUE("0", 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");
+       }
+
+       /* 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("Write completed, %d/%d bytes written", bytes_written, count);
+                       RETURN_VALUE("%d", bytes_written);
+               } else {
+                       RETURN_FAIL("WriteFile() failed");
+               }
+       } else {
+               DEBUG("Write completed immediately");
+               RETURN_VALUE("%d", 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);
+       }
+
+       /* 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_VALUE("%d", 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_VALUE("%d", 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");
+               }
+
+               bytes_written += result;
+               ptr += result;
+       }
+
+       RETURN_VALUE("%d", bytes_written);
+#endif
+}
+
+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("Writing up to %d bytes to port %s", count, port->name);
+
+       if (count == 0)
+               RETURN_VALUE("0", 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_VALUE("0", 0);
+               }
+       }
+
+       /* 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_VALUE("%d", ++written);
+                               }
+                       } else {
+                               /* Actual failure of some kind. */
+                               RETURN_FAIL("WriteFile() failed");
+                       }
+               } else {
+                       DEBUG("Single byte written immediately");
+                       written++;
+               }
+       }
+
+       DEBUG("All bytes written immediately");
+
+       RETURN_VALUE("%d", 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_VALUE("%d", written);
+#endif
+}
+
+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("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);
+
+       if (count == 0)
+               RETURN_VALUE("0", 0);
+
+#ifdef _WIN32
+       DWORD bytes_read = 0;
+
+       /* 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("Read completed, %d/%d bytes read", bytes_read, count);
+               } else {
+                       RETURN_FAIL("ReadFile() failed");
+               }
+       } else {
+               DEBUG("Read completed immediately");
+               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");
+       }
+
+       RETURN_VALUE("%d", 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_VALUE("%d", bytes_read);
+                       timersub(&end, &now, &delta);
+               }
+               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_VALUE("%d", bytes_read);
+               }
+
+               /* 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;
+       }
+
+       RETURN_VALUE("%d", bytes_read);
+#endif
+}
+
+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("Reading up to %d bytes from port %s", count, port->name);
+
+#ifdef _WIN32
+       DWORD bytes_read;
+
+       /* 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");
+
+       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");
+               }
+       }
+
+       RETURN_VALUE("%d", 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_VALUE("%d", bytes_read);
+#endif
+}
+
+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);
+
+#ifdef _WIN32
+       DWORD errors;
+       COMSTAT comstat;
+
+       if (ClearCommError(port->hdl, &errors, &comstat) == 0)
+               RETURN_FAIL("ClearCommError() failed");
+       RETURN_VALUE("%d", comstat.cbInQue);
+#else
+       int bytes_waiting;
+       if (ioctl(port->fd, TIOCINQ, &bytes_waiting) < 0)
+               RETURN_FAIL("TIOCINQ ioctl failed");
+       RETURN_VALUE("%d", bytes_waiting);
+#endif
+}
+
+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);
+
+#ifdef _WIN32
+       DWORD errors;
+       COMSTAT comstat;
+
+       if (ClearCommError(port->hdl, &errors, &comstat) == 0)
+               RETURN_FAIL("ClearCommError() failed");
+       RETURN_VALUE("%d", comstat.cbOutQue);
+#else
+       int bytes_waiting;
+       if (ioctl(port->fd, TIOCOUTQ, &bytes_waiting) < 0)
+               RETURN_FAIL("TIOCOUTQ ioctl failed");
+       RETURN_VALUE("%d", bytes_waiting);
+#endif
+}
+
+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");
+
+       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->handles = new_handles;
+       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();
+}
+
+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_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
+       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();
+}
+
+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();
+}
+
+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");
+
+       if (!(data = malloc(get_termios_size())))
+               RETURN_ERROR(SP_ERR_MEM, "termios malloc failed");
+
+       if (ioctl(fd, get_termios_get_ioctl(), data) < 0) {
+               free(data);
+               RETURN_FAIL("getting termios failed");
+       }
+
+       *baudrate = get_termios_speed(data);
+
+       free(data);
+
+       RETURN_OK();
+}
+
+static enum sp_return set_baudrate(int fd, int baudrate)
+{
+       void *data;
+
+       TRACE("%d, %d", fd, baudrate);
+
+       DEBUG("Getting baud rate");
+
+       if (!(data = malloc(get_termios_size())))
+               RETURN_ERROR(SP_ERR_MEM, "termios malloc failed");
+
+       if (ioctl(fd, get_termios_get_ioctl(), data) < 0) {
+               free(data);
+               RETURN_FAIL("getting termios failed");
+       }
+
+       DEBUG("Setting baud rate");
+
+       set_termios_speed(data, baudrate);
+
+       if (ioctl(fd, get_termios_set_ioctl(), data) < 0) {
+               free(data);
+               RETURN_FAIL("setting termios failed");
+       }
+
+       free(data);
+
+       RETURN_OK();
+}
+#endif /* USE_TERMIOS_SPEED */
+
+#ifdef USE_TERMIOX
+static enum sp_return get_flow(int fd, struct port_data *data)
+{
+       void *termx;
+
+       TRACE("%d, %p", fd, data);
+
+       DEBUG("Getting advanced flow control");
+
+       if (!(termx = malloc(get_termiox_size())))
+               RETURN_ERROR(SP_ERR_MEM, "termiox malloc failed");
+
+       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();
+}
+
+static enum sp_return set_flow(int fd, struct port_data *data)
+{
+       void *termx;
+
+       TRACE("%d, %p", fd, data);
+
+       DEBUG("Getting advanced flow control");
+
+       if (!(termx = malloc(get_termiox_size())))
+               RETURN_ERROR(SP_ERR_MEM, "termiox malloc failed");
+
+       if (ioctl(fd, TCGETX, termx) < 0) {
+               free(termx);
+               RETURN_FAIL("getting termiox failed");
+       }
+
+       DEBUG("Setting advanced flow control");
+
+       set_termiox_flow(termx, data->rts_flow, data->cts_flow,
+                       data->dtr_flow, data->dsr_flow);
+
+       if (ioctl(fd, TCSETX, termx) < 0) {
+               free(termx);
+               RETURN_FAIL("setting termiox failed");
+       }
+
+       free(termx);
+
+       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("Getting configuration for port %s", port->name);
+
+#ifdef _WIN32
+       if (!GetCommState(port->hdl, &data->dcb))
+               RETURN_FAIL("GetCommState() failed");
+
+       for (i = 0; i < NUM_STD_BAUDRATES; i++) {
+               if (data->dcb.BaudRate == std_baudrates[i].index) {
+                       config->baudrate = std_baudrates[i].value;
+                       break;
+               }
+       }
+
+       if (i == NUM_STD_BAUDRATES)
+               /* BaudRate field can be either an index or a custom baud rate. */
+               config->baudrate = data->dcb.BaudRate;
+
+       config->bits = data->dcb.ByteSize;
+
+       if (data->dcb.fParity)
+               switch (data->dcb.Parity) {
+               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 MARKPARITY:
+                       config->parity = SP_PARITY_MARK;
+                       break;
+               case SPACEPARITY:
+                       config->parity = SP_PARITY_SPACE;
+                       break;
+               default:
+                       config->parity = -1;
+               }
+       else
+               config->parity = SP_PARITY_NONE;
+
+       switch (data->dcb.StopBits) {
+       case ONESTOPBIT:
+               config->stopbits = 1;
+               break;
+       case TWOSTOPBITS:
+               config->stopbits = 2;
+               break;
+       default:
+               config->stopbits = -1;
+       }
+
+       switch (data->dcb.fRtsControl) {
+       case RTS_CONTROL_DISABLE:
+               config->rts = SP_RTS_OFF;
+               break;
+       case RTS_CONTROL_ENABLE:
+               config->rts = SP_RTS_ON;
+               break;
+       case RTS_CONTROL_HANDSHAKE:
+               config->rts = SP_RTS_FLOW_CONTROL;
+               break;
+       default:
+               config->rts = -1;
+       }
+
+       config->cts = data->dcb.fOutxCtsFlow ? SP_CTS_FLOW_CONTROL : SP_CTS_IGNORE;
+
+       switch (data->dcb.fDtrControl) {
+       case DTR_CONTROL_DISABLE:
+               config->dtr = SP_DTR_OFF;
+               break;
+       case DTR_CONTROL_ENABLE:
+               config->dtr = SP_DTR_ON;
+               break;
+       case DTR_CONTROL_HANDSHAKE:
+               config->dtr = SP_DTR_FLOW_CONTROL;
+               break;
+       default:
+               config->dtr = -1;
+       }
+
+       config->dsr = data->dcb.fOutxDsrFlow ? SP_DSR_FLOW_CONTROL : SP_DSR_IGNORE;
+
+       if (data->dcb.fInX) {
+               if (data->dcb.fOutX)
+                       config->xon_xoff = SP_XONXOFF_INOUT;
+               else
+                       config->xon_xoff = SP_XONXOFF_IN;
+       } else {
+               if (data->dcb.fOutX)
+                       config->xon_xoff = SP_XONXOFF_OUT;
+               else
+                       config->xon_xoff = SP_XONXOFF_DISABLED;
+       }
+
+#else // !_WIN32
+
+       if (tcgetattr(port->fd, &data->term) < 0)
+               RETURN_FAIL("tcgetattr() failed");
+
+       if (ioctl(port->fd, TIOCMGET, &data->controlbits) < 0)
+               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;
+                       break;
+               }
+       }
+
+       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
+       }
+
+       switch (data->term.c_cflag & CSIZE) {
+       case CS8:
+               config->bits = 8;
+               break;
+       case CS7:
+               config->bits = 7;
+               break;
+       case CS6:
+               config->bits = 6;
+               break;
+       case CS5:
+               config->bits = 5;
+               break;
+       default:
+               config->bits = -1;
+       }
+
+       if (!(data->term.c_cflag & PARENB) && (data->term.c_iflag & IGNPAR))
+               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;
+
+       config->stopbits = (data->term.c_cflag & CSTOPB) ? 2 : 1;
+
+       if (data->term.c_cflag & CRTSCTS) {
+               config->rts = SP_RTS_FLOW_CONTROL;
+               config->cts = SP_CTS_FLOW_CONTROL;
+       } else {
+               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;
+       }
+
+       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)
+                       config->xon_xoff = SP_XONXOFF_INOUT;
+               else
+                       config->xon_xoff = SP_XONXOFF_IN;
+       } else {
+               if (data->term.c_iflag & IXON)
+                       config->xon_xoff = SP_XONXOFF_OUT;
+               else
+                       config->xon_xoff = SP_XONXOFF_DISABLED;
+       }
+#endif
+
+       RETURN_OK();
+}
+
+static enum sp_return set_config(struct sp_port *port, struct port_data *data,
+       const struct sp_port_config *config)
+{
+       unsigned int i;
+#ifdef __APPLE__
+       BAUD_TYPE baud_nonstd;
+
+       baud_nonstd = B0;
+#endif
+#ifdef USE_TERMIOS_SPEED
+       int baud_nonstd = 0;
+#endif
+
+       TRACE("%p, %p, %p", port, data, config);
+
+       DEBUG("Setting configuration for port %s", port->name);
+
+#ifdef _WIN32
+       if (config->baudrate >= 0) {
+               for (i = 0; i < NUM_STD_BAUDRATES; i++) {
+                       if (config->baudrate == std_baudrates[i].value) {
+                               data->dcb.BaudRate = std_baudrates[i].index;
+                               break;
+                       }
+               }
+
+               if (i == NUM_STD_BAUDRATES)
+                       data->dcb.BaudRate = config->baudrate;
+       }
+
+       if (config->bits >= 0)
+               data->dcb.ByteSize = config->bits;
+
+       if (config->parity >= 0) {
+               switch (config->parity) {
+               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_MARK:
+                       data->dcb.Parity = MARKPARITY;
+                       break;
+               case SP_PARITY_SPACE:
+                       data->dcb.Parity = SPACEPARITY;
+                       break;
+               default:
+                       RETURN_ERROR(SP_ERR_ARG, "Invalid parity setting");
+               }
+       }
+
+       if (config->stopbits >= 0) {
+               switch (config->stopbits) {
+               /* Note: There's also ONE5STOPBITS == 1.5 (unneeded so far). */
+               case 1:
+                       data->dcb.StopBits = ONESTOPBIT;
+                       break;
+               case 2:
+                       data->dcb.StopBits = TWOSTOPBITS;
+                       break;
+               default:
+                       RETURN_ERROR(SP_ERR_ARG, "Invalid stop bit setting");
+               }
+       }
+
+       if (config->rts >= 0) {
+               switch (config->rts) {
+               case SP_RTS_OFF:
+                       data->dcb.fRtsControl = RTS_CONTROL_DISABLE;
+                       break;
+               case SP_RTS_ON:
+                       data->dcb.fRtsControl = RTS_CONTROL_ENABLE;
+                       break;
+               case SP_RTS_FLOW_CONTROL:
+                       data->dcb.fRtsControl = RTS_CONTROL_HANDSHAKE;
+                       break;
+               default:
+                       RETURN_ERROR(SP_ERR_ARG, "Invalid RTS setting");
+               }
+       }
+
+       if (config->cts >= 0) {
+               switch (config->cts) {
+               case SP_CTS_IGNORE:
+                       data->dcb.fOutxCtsFlow = FALSE;
+                       break;
+               case SP_CTS_FLOW_CONTROL:
+                       data->dcb.fOutxCtsFlow = TRUE;
+                       break;
+               default:
+                       RETURN_ERROR(SP_ERR_ARG, "Invalid CTS setting");
+               }
+       }
+
+       if (config->dtr >= 0) {
+               switch (config->dtr) {
+               case SP_DTR_OFF:
+                       data->dcb.fDtrControl = DTR_CONTROL_DISABLE;
+                       break;
+               case SP_DTR_ON:
+                       data->dcb.fDtrControl = DTR_CONTROL_ENABLE;
+                       break;
+               case SP_DTR_FLOW_CONTROL:
+                       data->dcb.fDtrControl = DTR_CONTROL_HANDSHAKE;
+                       break;
+               default:
+                       RETURN_ERROR(SP_ERR_ARG, "Invalid DTR setting");
+               }
+       }
+
+       if (config->dsr >= 0) {
+               switch (config->dsr) {
+               case SP_DSR_IGNORE:
+                       data->dcb.fOutxDsrFlow = FALSE;
+                       break;
+               case SP_DSR_FLOW_CONTROL:
+                       data->dcb.fOutxDsrFlow = TRUE;
+                       break;
+               default:
+                       RETURN_ERROR(SP_ERR_ARG, "Invalid DSR setting");
+               }
+       }
+
+       if (config->xon_xoff >= 0) {
+               switch (config->xon_xoff) {
+               case SP_XONXOFF_DISABLED:
+                       data->dcb.fInX = FALSE;
+                       data->dcb.fOutX = FALSE;
+                       break;
+               case SP_XONXOFF_IN:
+                       data->dcb.fInX = TRUE;
+                       data->dcb.fOutX = FALSE;
+                       break;
+               case SP_XONXOFF_OUT:
+                       data->dcb.fInX = FALSE;
+                       data->dcb.fOutX = TRUE;
+                       break;
+               case SP_XONXOFF_INOUT:
+                       data->dcb.fInX = TRUE;
+                       data->dcb.fOutX = TRUE;
+                       break;
+               default:
+                       RETURN_ERROR(SP_ERR_ARG, "Invalid XON/XOFF setting");
+               }
+       }
+
+       if (!SetCommState(port->hdl, &data->dcb))
+               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_FAIL("cfsetospeed() failed");
+
+                               if (cfsetispeed(&data->term, std_baudrates[i].index) < 0)
+                                       RETURN_FAIL("cfsetispeed() failed");
+                               break;
+                       }
+               }
+
+               /* Non-standard baud rate */
+               if (i == NUM_STD_BAUDRATES) {
+#ifdef __APPLE__
+                       /* Set "dummy" baud rate. */
+                       if (cfsetspeed(&data->term, B9600) < 0)
+                               RETURN_FAIL("cfsetspeed() failed");
+                       baud_nonstd = config->baudrate;
+#elif defined(USE_TERMIOS_SPEED)
+                       baud_nonstd = 1;
+#else
+                       RETURN_ERROR(SP_ERR_SUPP, "Non-standard baudrate not supported");
+#endif
+               }
+       }
+
+       if (config->bits >= 0) {
+               data->term.c_cflag &= ~CSIZE;
+               switch (config->bits) {
+               case 8:
+                       data->term.c_cflag |= CS8;
+                       break;
+               case 7:
+                       data->term.c_cflag |= CS7;
+                       break;
+               case 6:
+                       data->term.c_cflag |= CS6;
+                       break;
+               case 5:
+                       data->term.c_cflag |= CS5;
+                       break;
+               default:
+                       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;
+                       break;
+               case SP_PARITY_EVEN:
+                       data->term.c_cflag |= PARENB;
+                       break;
+               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_ERROR(SP_ERR_ARG, "Invalid parity setting");
+               }
+       }
+
+       if (config->stopbits >= 0) {
+               data->term.c_cflag &= ~CSTOPB;
+               switch (config->stopbits) {
+               case 1:
+                       data->term.c_cflag &= ~CSTOPB;
+                       break;
+               case 2:
+                       data->term.c_cflag |= CSTOPB;
+                       break;
+               default:
+                       RETURN_ERROR(SP_ERR_ARG, "Invalid stop bits setting");
+               }
+       }
+
+       if (config->rts >= 0 || config->cts >= 0) {
+               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;
+                       }
+                       if (config->cts == SP_CTS_FLOW_CONTROL)
+                               data->cts_flow = 1;
+
+                       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 {
+                               /* 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) {
+               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");
+                       }
                }
        }
-out:
-       udev_enumerate_unref(ud_enumerate);
-       udev_unref(ud);
-#endif
 
-       if (ret == SP_OK)
-       {
-               *list_ptr = list;
+       if (config->xon_xoff >= 0) {
+               data->term.c_iflag &= ~(IXON | IXOFF | IXANY);
+               switch (config->xon_xoff) {
+               case SP_XONXOFF_DISABLED:
+                       break;
+               case SP_XONXOFF_IN:
+                       data->term.c_iflag |= IXOFF;
+                       break;
+               case SP_XONXOFF_OUT:
+                       data->term.c_iflag |= IXON | IXANY;
+                       break;
+               case SP_XONXOFF_INOUT:
+                       data->term.c_iflag |= IXON | IXOFF | IXANY;
+                       break;
+               default:
+                       RETURN_ERROR(SP_ERR_ARG, "Invalid XON/XOFF setting");
+               }
        }
-       else
-       {
-               if (list)
-                       sp_free_port_list(list);
 
-               *list_ptr = NULL;
-       }
+       if (tcsetattr(port->fd, TCSANOW, &data->term) < 0)
+               RETURN_FAIL("tcsetattr() failed");
 
-       return ret;
-}
+#ifdef __APPLE__
+       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(). */
+               if (cfsetspeed(&data->term, baud_nonstd) < 0)
+                       RETURN_FAIL("cfsetspeed() failed");
+       }
+#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
 
-void sp_free_port_list(struct sp_port **list)
-{
-       unsigned int i;
+#endif /* !_WIN32 */
 
-       for (i = 0; list[i]; i++)
-               sp_free_port(list[i]);
-       free(list);
+       RETURN_OK();
 }
 
-static int sp_validate_port(struct sp_port *port)
+enum sp_return sp_new_config(struct sp_port_config **config_ptr)
 {
-       if (port == NULL)
-               return 0;
-#ifdef _WIN32
-       if (port->hdl == INVALID_HANDLE_VALUE)
-               return 0;
-#else
-       if (port->fd < 0)
-               return 0;
-#endif
-       return 1;
-}
+       struct sp_port_config *config;
 
-#define CHECK_PORT() do { if (!sp_validate_port(port)) return SP_ERR_ARG; } while (0)
-
-int sp_open(struct sp_port *port, int flags)
-{
-       if (!port)
-               return SP_ERR_ARG;
+       TRACE("%p", config_ptr);
 
-#ifdef _WIN32
-       DWORD desired_access = 0, flags_and_attributes = 0;
-       char *escaped_port_name;
+       if (!config_ptr)
+               RETURN_ERROR(SP_ERR_ARG, "Null result pointer");
 
-       /* 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);
+       *config_ptr = NULL;
 
-       /* 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 (!(config = malloc(sizeof(struct sp_port_config))))
+               RETURN_ERROR(SP_ERR_MEM, "config malloc failed");
 
-       port->hdl = CreateFile(escaped_port_name, desired_access, 0, 0,
-                        OPEN_EXISTING, flags_and_attributes, 0);
+       config->baudrate = -1;
+       config->bits = -1;
+       config->parity = -1;
+       config->stopbits = -1;
+       config->rts = -1;
+       config->cts = -1;
+       config->dtr = -1;
+       config->dsr = -1;
 
-       free(escaped_port_name);
+       *config_ptr = config;
 
-       if (port->hdl == INVALID_HANDLE_VALUE)
-               return SP_ERR_FAIL;
-#else
-       int flags_local = 0;
+       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;
+void sp_free_config(struct sp_port_config *config)
+{
+       TRACE("%p", config);
 
-       if ((port->fd = open(port->name, flags_local)) < 0)
-               return SP_ERR_FAIL;
-#endif
+       if (!config)
+               DEBUG("Null config");
+       else
+               free(config);
 
-       return SP_OK;
+       RETURN();
 }
 
-int sp_close(struct sp_port *port)
+enum sp_return sp_get_config(struct sp_port *port, struct sp_port_config *config)
 {
-       CHECK_PORT();
+       struct port_data data;
 
-#ifdef _WIN32
-       /* Returns non-zero upon success, 0 upon failure. */
-       if (CloseHandle(port->hdl) == 0)
-               return SP_ERR_FAIL;
-#else
-       /* Returns 0 upon success, -1 upon failure. */
-       if (close(port->fd) == -1)
-               return SP_ERR_FAIL;
-#endif
+       TRACE("%p, %p", port, config);
 
-       return SP_OK;
-}
+       CHECK_OPEN_PORT();
 
-int sp_flush(struct sp_port *port)
-{
-       CHECK_PORT();
+       if (!config)
+               RETURN_ERROR(SP_ERR_ARG, "Null config");
 
-#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;
+       TRY(get_config(port, &data, config));
+
+       RETURN_OK();
 }
 
-int sp_write(struct sp_port *port, const void *buf, size_t count)
+enum sp_return sp_set_config(struct sp_port *port, const struct sp_port_config *config)
 {
-       CHECK_PORT();
+       struct port_data data;
+       struct sp_port_config prev_config;
 
-       if (!buf)
-               return SP_ERR_ARG;
+       TRACE("%p, %p", port, config);
 
-#ifdef _WIN32
-       DWORD written = 0;
+       CHECK_OPEN_PORT();
 
-       /* 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 (!config)
+               RETURN_ERROR(SP_ERR_ARG, "Null config");
 
-       if (written < 0)
-               return SP_ERR_FAIL;
-       else
-               return written;
-#endif
+       TRY(get_config(port, &data, &prev_config));
+       TRY(set_config(port, &data, config));
+
+       RETURN_OK();
+}
+
+#define CREATE_ACCESSORS(x, type) \
+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); \
+       CHECK_OPEN_PORT(); \
+       TRY(get_config(port, &data, &config)); \
+       config.x = x; \
+       TRY(set_config(port, &data, &config)); \
+       RETURN_OK(); \
+} \
+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) { \
+       TRACE("%p, %d", config, x); \
+       if (!config) \
+               RETURN_ERROR(SP_ERR_ARG, "Null config"); \
+       config->x = x; \
+       RETURN_OK(); \
 }
 
-int sp_read(struct sp_port *port, void *buf, size_t count)
+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)
+
+enum sp_return sp_set_config_flowcontrol(struct sp_port_config *config, enum sp_flowcontrol flowcontrol)
 {
-       CHECK_PORT();
+       if (!config)
+               RETURN_ERROR(SP_ERR_ARG, "Null configuration");
 
-       if (!buf)
-               return SP_ERR_ARG;
+       if (flowcontrol > SP_FLOWCONTROL_DTRDSR)
+               RETURN_ERROR(SP_ERR_ARG, "Invalid flow control setting");
 
-#ifdef _WIN32
-       DWORD bytes_read = 0;
+       if (flowcontrol == SP_FLOWCONTROL_XONXOFF)
+               config->xon_xoff = SP_XONXOFF_INOUT;
+       else
+               config->xon_xoff = SP_XONXOFF_DISABLED;
+
+       if (flowcontrol == SP_FLOWCONTROL_RTSCTS) {
+               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;
+       }
 
-       /* 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;
+       if (flowcontrol == SP_FLOWCONTROL_DTRDSR) {
+               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;
+       }
 
-       /* 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();
 }
 
-static int start_config(struct sp_port *port, struct sp_port_data *data)
+enum sp_return sp_set_flowcontrol(struct sp_port *port, enum sp_flowcontrol flowcontrol)
 {
-       CHECK_PORT();
-#ifdef _WIN32
-       if (!GetCommState(port->hdl, &data->dcb))
-               return SP_ERR_FAIL;
-#else
-       if (tcgetattr(port->fd, &data->term) < 0)
-               return SP_ERR_FAIL;
-#endif
-       return SP_OK;
-}
+       struct port_data data;
+       struct sp_port_config config;
 
-static int set_baudrate(struct sp_port_data *data, int baudrate)
-{
-#ifdef _WIN32
-       switch (baudrate) {
-       /*
-        * The baudrates 50/75/134/150/200/1800/230400/460800 do not seem to
-        * have documented CBR_* macros.
-        */
-       case 110:
-               data->dcb.BaudRate = CBR_110;
-               break;
-       case 300:
-               data->dcb.BaudRate = CBR_300;
-               break;
-       case 600:
-               data->dcb.BaudRate = CBR_600;
-               break;
-       case 1200:
-               data->dcb.BaudRate = CBR_1200;
-               break;
-       case 2400:
-               data->dcb.BaudRate = CBR_2400;
-               break;
-       case 4800:
-               data->dcb.BaudRate = CBR_4800;
-               break;
-       case 9600:
-               data->dcb.BaudRate = CBR_9600;
-               break;
-       case 14400:
-               data->dcb.BaudRate = CBR_14400; /* Not available on Unix? */
-               break;
-       case 19200:
-               data->dcb.BaudRate = CBR_19200;
-               break;
-       case 38400:
-               data->dcb.BaudRate = CBR_38400;
-               break;
-       case 57600:
-               data->dcb.BaudRate = CBR_57600;
-               break;
-       case 115200:
-               data->dcb.BaudRate = CBR_115200;
-               break;
-       case 128000:
-               data->dcb.BaudRate = CBR_128000; /* Not available on Unix? */
-               break;
-       case 256000:
-               data->dcb.BaudRate = CBR_256000; /* Not available on Unix? */
-               break;
-       default:
-               return SP_ERR_ARG;
-       }
-#else
-       speed_t baud;
-       switch (baudrate) {
-       case 50:
-               baud = B50;
-               break;
-       case 75:
-               baud = B75;
-               break;
-       case 110:
-               baud = B110;
-               break;
-       case 134:
-               baud = B134;
-               break;
-       case 150:
-               baud = B150;
-               break;
-       case 200:
-               baud = B200;
-               break;
-       case 300:
-               baud = B300;
-               break;
-       case 600:
-               baud = B600;
-               break;
-       case 1200:
-               baud = B1200;
-               break;
-       case 1800:
-               baud = B1800;
-               break;
-       case 2400:
-               baud = B2400;
-               break;
-       case 4800:
-               baud = B4800;
-               break;
-       case 9600:
-               baud = B9600;
-               break;
-       case 19200:
-               baud = B19200;
-               break;
-       case 38400:
-               baud = B38400;
-               break;
-       case 57600:
-               baud = B57600;
-               break;
-       case 115200:
-               baud = B115200;
-               break;
-       case 230400:
-               baud = B230400;
-               break;
-#if !defined(__APPLE__) && !defined(__OpenBSD__)
-       case 460800:
-               baud = B460800;
-               break;
-#endif
-       default:
-               return SP_ERR_ARG;
-       }
+       TRACE("%p, %d", port, flowcontrol);
 
-       if (cfsetospeed(&data->term, baud) < 0)
-               return SP_ERR_FAIL;
+       CHECK_OPEN_PORT();
 
-       if (cfsetispeed(&data->term, baud) < 0)
-               return SP_ERR_FAIL;
+       TRY(get_config(port, &data, &config));
 
-#endif
-       return SP_OK;
-}
+       TRY(sp_set_config_flowcontrol(&config, flowcontrol));
 
-static int set_bits(struct sp_port_data *data, int bits)
-{
-#ifdef _WIN32
-       data->dcb.ByteSize = bits;
-#else
-       data->term.c_cflag &= ~CSIZE;
-       switch (bits) {
-       case 8:
-               data->term.c_cflag |= CS8;
-               break;
-       case 7:
-               data->term.c_cflag |= CS7;
-               break;
-       case 6:
-               data->term.c_cflag |= CS6;
-               break;
-       default:
-               return SP_ERR_ARG;
-       }
-#endif
-       return SP_OK;
-}
+       TRY(set_config(port, &data, &config));
 
-static int set_parity(struct sp_port_data *data, int parity)
-{
-#ifdef _WIN32
-       switch (parity) {
-       /* Note: There's also SPACEPARITY, MARKPARITY (unneeded so far). */
-       case SP_PARITY_NONE:
-               data->dcb.Parity = NOPARITY;
-               break;
-       case SP_PARITY_EVEN:
-               data->dcb.Parity = EVENPARITY;
-               break;
-       case SP_PARITY_ODD:
-               data->dcb.Parity = ODDPARITY;
-               break;
-       default:
-               return SP_ERR_ARG;
-       }
-#else
-       data->term.c_iflag &= ~IGNPAR;
-       data->term.c_cflag &= ~(PARENB | PARODD);
-       switch (parity) {
-       case SP_PARITY_NONE:
-               data->term.c_iflag |= IGNPAR;
-               break;
-       case SP_PARITY_EVEN:
-               data->term.c_cflag |= PARENB;
-               break;
-       case SP_PARITY_ODD:
-               data->term.c_cflag |= PARENB | PARODD;
-               break;
-       default:
-               return SP_ERR_ARG;
-       }
-#endif
-       return SP_OK;
+       RETURN_OK();
 }
 
-static int set_stopbits(struct sp_port_data *data, int stopbits)
+enum sp_return sp_get_signals(struct sp_port *port, enum sp_signal *signals)
 {
-#ifdef _WIN32
-       switch (stopbits) {
-       /* Note: There's also ONE5STOPBITS == 1.5 (unneeded so far). */
-       case 1:
-               data->dcb.StopBits = ONESTOPBIT;
-               break;
-       case 2:
-               data->dcb.StopBits = TWOSTOPBITS;
-               break;
-       default:
-               return SP_ERR_ARG;
-       }
-#else
-       data->term.c_cflag &= ~CSTOPB;
-       switch (stopbits) {
-       case 1:
-               data->term.c_cflag &= ~CSTOPB;
-               break;
-       case 2:
-               data->term.c_cflag |= CSTOPB;
-               break;
-       default:
-               return SP_ERR_ARG;
-       }
-#endif
-       return SP_OK;
-}
+       TRACE("%p, %p", port, signals);
 
-static int set_flowcontrol(struct sp_port_data *data, int flowcontrol)
-{
-#ifndef _WIN32
-       data->term.c_iflag &= ~(IXON | IXOFF | IXANY);
-       data->term.c_cflag &= ~CRTSCTS;
-       switch (flowcontrol) {
-       case 0:
-               /* No flow control. */
-               break;
-       case 1:
-               data->term.c_cflag |= CRTSCTS;
-               break;
-       case 2:
-               data->term.c_iflag |= IXON | IXOFF | IXANY;
-               break;
-       default:
-               return SP_ERR_ARG;
-       }
-#endif
-       return SP_OK;
-}
+       CHECK_OPEN_PORT();
 
-static int set_rts(struct sp_port_data *data, int rts)
-{
-#ifdef _WIN32
-       if (rts)
-               data->dcb.fRtsControl = RTS_CONTROL_ENABLE;
-       else
-               data->dcb.fRtsControl = RTS_CONTROL_DISABLE;
-#else
-       data->rts = rts;
-#endif
-       return SP_OK;
-}
+       if (!signals)
+               RETURN_ERROR(SP_ERR_ARG, "Null result pointer");
 
-static int set_dtr(struct sp_port_data *data, int dtr)
-{
+       DEBUG("Getting control signals for port %s", port->name);
+
+       *signals = 0;
 #ifdef _WIN32
-       if (dtr)
-               data->dcb.fDtrControl = DTR_CONTROL_ENABLE;
-       else
-               data->dcb.fDtrControl = DTR_CONTROL_DISABLE;
+       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
-       data->dtr = dtr;
+       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 SP_OK;
+       RETURN_OK();
 }
 
-static int apply_config(struct sp_port *port, struct sp_port_data *data)
+enum sp_return sp_start_break(struct sp_port *port)
 {
+       TRACE("%p", port);
+
+       CHECK_OPEN_PORT();
 #ifdef _WIN32
-       if (!SetCommState(port->hdl, &data->dcb))
-               return SP_ERR_FAIL;
+       if (SetCommBreak(port->hdl) == 0)
+               RETURN_FAIL("SetCommBreak() failed");
 #else
-       int controlbits;
-
-       /* 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;
+       if (ioctl(port->fd, TIOCSBRK, 1) < 0)
+               RETURN_FAIL("TIOCSBRK ioctl failed");
 #endif
-       /* Disable canonical mode, and don't echo input characters. */
-       data->term.c_lflag &= ~(ICANON | ECHO);
-
-       /* Ignore modem status lines; enable receiver */
-       data->term.c_cflag |= (CLOCAL | CREAD);
-
-       /* Write the configured settings. */
-       if (tcsetattr(port->fd, TCSADRAIN, &data->term) < 0)
-               return SP_ERR_FAIL;
-
-       if (data->rts != -1) {
-               controlbits = TIOCM_RTS;
-               if (ioctl(port->fd, data->rts ? TIOCMBIS : TIOCMBIC,
-                               &controlbits) < 0)
-                       return SP_ERR_FAIL;
-       }
 
-       if (data->dtr != -1) {
-               controlbits = TIOCM_DTR;
-               if (ioctl(port->fd, data->dtr ? TIOCMBIS : TIOCMBIC,
-                               &controlbits) < 0)
-                       return SP_ERR_FAIL;
-       }
-#endif
-       return SP_OK;
+       RETURN_OK();
 }
 
-#define TRY(x) do { int ret = x; if (ret != SP_OK) return ret; } while (0)
-#define TRY_SET(x) do { if (config->x >= 0) TRY(set_##x(&data, config->x)); } while (0)
-
-int sp_set_config(struct sp_port *port, struct sp_port_config *config)
+enum sp_return sp_end_break(struct sp_port *port)
 {
-       struct sp_port_data data;
+       TRACE("%p", port);
 
-       TRY(start_config(port, &data));
-       TRY_SET(baudrate);
-       TRY_SET(bits);
-       TRY_SET(parity);
-       TRY_SET(stopbits);
-       TRY_SET(flowcontrol);
-       TRY_SET(rts);
-       TRY_SET(dtr);
-       TRY(apply_config(port, &data));
+       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 SP_OK;
+       RETURN_OK();
 }
 
 int sp_last_error_code(void)
 {
+       TRACE("");
 #ifdef _WIN32
-       return GetLastError();
+       RETURN_VALUE("%d", GetLastError());
 #else
-       return errno;
+       RETURN_VALUE("%d", errno);
 #endif
 }
 
 char *sp_last_error_message(void)
 {
+       TRACE("");
+
 #ifdef _WIN32
        LPVOID message;
        DWORD error = GetLastError();
@@ -861,17 +3255,83 @@ char *sp_last_error_message(void)
                (LPTSTR) &message,
                0, NULL );
 
-       return message;
+       RETURN_VALUE("%s", message);
 #else
-       return strerror(errno);
+       RETURN_VALUE("%s", strerror(errno));
 #endif
 }
 
 void sp_free_error_message(char *message)
 {
+       TRACE("%s", message);
+
 #ifdef _WIN32
        LocalFree(message);
 #else
        (void)message;
 #endif
+
+       RETURN();
+}
+
+void sp_set_debug_handler(void (*handler)(const char *format, ...))
+{
+       TRACE("%p", handler);
+
+       sp_debug_handler = handler;
+
+       RETURN();
+}
+
+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);
+}
+
+int sp_get_major_package_version(void)
+{
+       return SP_PACKAGE_VERSION_MAJOR;
+}
+
+int sp_get_minor_package_version(void)
+{
+       return SP_PACKAGE_VERSION_MINOR;
+}
+
+int sp_get_micro_package_version(void)
+{
+       return SP_PACKAGE_VERSION_MICRO;
 }
+
+const char *sp_get_package_version_string(void)
+{
+       return SP_PACKAGE_VERSION_STRING;
+}
+
+int sp_get_current_lib_version(void)
+{
+       return SP_LIB_VERSION_CURRENT;
+}
+
+int sp_get_revision_lib_version(void)
+{
+       return SP_LIB_VERSION_REVISION;
+}
+
+int sp_get_age_lib_version(void)
+{
+       return SP_LIB_VERSION_AGE;
+}
+
+const char *sp_get_lib_version_string(void)
+{
+       return SP_LIB_VERSION_STRING;
+}
+
+/** @} */