diff --git a/libnfc/buses/Makefile.am b/libnfc/buses/Makefile.am
index 2ce0720..23cf46f 100644
--- a/libnfc/buses/Makefile.am
+++ b/libnfc/buses/Makefile.am
@@ -3,7 +3,7 @@
 AM_CPPFLAGS = $(all_includes) $(LIBNFC_CFLAGS)
 
 noinst_LTLIBRARIES = libnfcbuses.la
-libnfcbuses_la_SOURCES = uart.c uart.h
+libnfcbuses_la_SOURCES = uart.c uart.h usbbus.c usbbus.h
 libnfcbuses_la_CFLAGS = -I$(top_srcdir)/libnfc
 
 EXTRA_DIST = uart_posix.c uart_win32.c
diff --git a/libnfc/buses/usbbus.c b/libnfc/buses/usbbus.c
new file mode 100644
index 0000000..fcf4233
--- /dev/null
+++ b/libnfc/buses/usbbus.c
@@ -0,0 +1,61 @@
+/*-
+ * Public platform independent Near Field Communication (NFC) library
+ *
+ * Copyright (C) 2013, Romuald Conty
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+/**
+ * @file usbbus.c
+ * @brief libusb 0.1 driver wrapper
+ */
+
+#ifdef HAVE_CONFIG_H
+#  include "config.h"
+#endif // HAVE_CONFIG_H
+
+#include "usbbus.h"
+#include "log.h"
+#define LOG_CATEGORY "libnfc.buses.usbbus"
+#define LOG_GROUP    NFC_LOG_GROUP_DRIVER
+
+// Global flag to know if usb_init() has already been called or not
+bool usb_initialized=false;
+
+int usb_prepare(void) {
+  if (usb_initialized)
+    return 0;
+  usb_init();
+  usb_initialized = true;
+
+  int res;
+  // usb_find_busses will find all of the busses on the system. Returns the
+  // number of changes since previous call to this function (total of new
+  // busses and busses removed).
+  if ((res = usb_find_busses()) < 0) {
+    log_put(LOG_GROUP, LOG_CATEGORY, NFC_LOG_PRIORITY_ERROR, "Unable to find USB busses (%s)", _usb_strerror(res));
+    return -1;
+  }
+  // usb_find_devices will find all of the devices on each bus. This should be
+  // called after usb_find_busses. Returns the number of changes since the
+  // previous call to this function (total of new device and devices removed).
+  if ((res = usb_find_devices()) < 0) {
+    log_put(LOG_GROUP, LOG_CATEGORY, NFC_LOG_PRIORITY_ERROR, "Unable to find USB devices (%s)", _usb_strerror(res));
+    return -1;
+  }
+  return 0;
+}
+
diff --git a/libnfc/buses/usbbus.h b/libnfc/buses/usbbus.h
new file mode 100644
index 0000000..5c08137
--- /dev/null
+++ b/libnfc/buses/usbbus.h
@@ -0,0 +1,49 @@
+/*-
+ * Public platform independent Near Field Communication (NFC) library
+ *
+ * Copyright (C) 2013, Romuald Conty
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+/**
+ * @file usbbus.h
+ * @brief libusb 0.1 driver header
+ */
+
+#ifndef __NFC_BUS_USB_H__
+#  define __NFC_BUS_USB_H__
+
+#ifndef _WIN32
+// Under POSIX system, we use libusb (>= 0.1.12)
+#include <usb.h>
+#define USB_TIMEDOUT ETIMEDOUT
+#define _usb_strerror( X ) strerror(-X)
+#else
+// Under Windows we use libusb-win32 (>= 1.2.5)
+#include <lusb0_usb.h>
+#define USB_TIMEDOUT 116
+#define _usb_strerror( X ) usb_strerror()
+#endif
+
+#include <stdbool.h>
+#include <string.h>
+
+// Global flag to know if usb_init() has already been called or not
+extern bool usb_initialized;
+
+int usb_prepare(void);
+
+#endif // __NFC_BUS_USB_H__
diff --git a/libnfc/drivers/acr122_usb.c b/libnfc/drivers/acr122_usb.c
index da14a60..5f35234 100644
--- a/libnfc/drivers/acr122_usb.c
+++ b/libnfc/drivers/acr122_usb.c
@@ -54,24 +54,12 @@ Thanks to d18c7db and Okko for example code
 #include <inttypes.h>
 #include <sys/select.h>
 #include <errno.h>
-
-#ifndef _WIN32
-// Under POSIX system, we use libusb (>= 0.1.12)
-#include <usb.h>
-#define USB_TIMEDOUT ETIMEDOUT
-#define _usb_strerror( X ) strerror(-X)
-#else
-// Under Windows we use libusb-win32 (>= 1.2.5)
-#include <lusb0_usb.h>
-#define USB_TIMEDOUT 116
-#define _usb_strerror( X ) usb_strerror()
-#endif
-
 #include <string.h>
 
 #include <nfc/nfc.h>
 
 #include "nfc-internal.h"
+#include "buses/usbbus.h"
 #include "chips/pn53x.h"
 #include "chips/pn53x-internal.h"
 #include "drivers/acr122_usb.h"
@@ -309,23 +297,8 @@ static size_t
 acr122_usb_scan(const nfc_context *context, nfc_connstring connstrings[], const size_t connstrings_len)
 {
   (void)context;
-  usb_init();
 
-  int res;
-  // usb_find_busses will find all of the busses on the system. Returns the
-  // number of changes since previous call to this function (total of new
-  // busses and busses removed).
-  if ((res = usb_find_busses()) < 0) {
-    log_put(LOG_GROUP, LOG_CATEGORY, NFC_LOG_PRIORITY_ERROR, "Unable to find USB busses (%s)", _usb_strerror(res));
-    return 0;
-  }
-  // usb_find_devices will find all of the devices on each bus. This should be
-  // called after usb_find_busses. Returns the number of changes since the
-  // previous call to this function (total of new device and devices removed).
-  if ((res = usb_find_devices()) < 0) {
-    log_put(LOG_GROUP, LOG_CATEGORY, NFC_LOG_PRIORITY_ERROR, "Unable to find USB devices (%s)", _usb_strerror(res));
-    return 0;
-  }
+  usb_prepare();
 
   size_t device_found = 0;
   uint32_t uiBusIndex = 0;
@@ -446,23 +419,7 @@ acr122_usb_open(const nfc_context *context, const nfc_connstring connstring)
   struct usb_bus *bus;
   struct usb_device *dev;
 
-  usb_init();
-
-  int res;
-  // usb_find_busses will find all of the busses on the system. Returns the
-  // number of changes since previous call to this function (total of new
-  // busses and busses removed).
-  if ((res = usb_find_busses()) < 0) {
-    log_put(LOG_GROUP, LOG_CATEGORY, NFC_LOG_PRIORITY_ERROR, "Unable to find USB busses (%s)", _usb_strerror(res));
-    goto free_mem;
-  }
-  // usb_find_devices will find all of the devices on each bus. This should be
-  // called after usb_find_busses. Returns the number of changes since the
-  // previous call to this function (total of new device and devices removed).
-  if ((res = usb_find_devices()) < 0) {
-    log_put(LOG_GROUP, LOG_CATEGORY, NFC_LOG_PRIORITY_ERROR, "Unable to find USB devices (%s)", _usb_strerror(res));
-    goto free_mem;
-  }
+  usb_prepare();
 
   for (bus = usb_get_busses(); bus; bus = bus->next) {
     if (connstring_decode_level > 1)  {
@@ -483,7 +440,7 @@ acr122_usb_open(const nfc_context *context, const nfc_connstring connstring)
       // Retrieve end points
       acr122_usb_get_end_points(dev, &data);
       // Claim interface
-      res = usb_claim_interface(data.pudh, 0);
+      int res = usb_claim_interface(data.pudh, 0);
       if (res < 0) {
         log_put(LOG_GROUP, LOG_CATEGORY, NFC_LOG_PRIORITY_ERROR, "Unable to claim USB interface (%s)", _usb_strerror(res));
         usb_close(data.pudh);
diff --git a/libnfc/drivers/pn53x_usb.c b/libnfc/drivers/pn53x_usb.c
index 6340cb7..905a951 100644
--- a/libnfc/drivers/pn53x_usb.c
+++ b/libnfc/drivers/pn53x_usb.c
@@ -37,24 +37,12 @@ Thanks to d18c7db and Okko for example code
 #include <inttypes.h>
 #include <sys/select.h>
 #include <errno.h>
-
-#ifndef _WIN32
-// Under POSIX system, we use libusb (>= 0.1.12)
-#include <usb.h>
-#define USB_TIMEDOUT ETIMEDOUT
-#define _usb_strerror( X ) strerror(-X)
-#else
-// Under Windows we use libusb-win32 (>= 1.2.5)
-#include <lusb0_usb.h>
-#define USB_TIMEDOUT 116
-#define _usb_strerror( X ) usb_strerror()
-#endif
-
 #include <string.h>
 
 #include <nfc/nfc.h>
 
 #include "nfc-internal.h"
+#include "buses/usbbus.h"
 #include "chips/pn53x.h"
 #include "chips/pn53x-internal.h"
 #include "drivers/pn53x_usb.h"
@@ -186,23 +174,7 @@ static size_t
 pn53x_usb_scan(const nfc_context *context, nfc_connstring connstrings[], const size_t connstrings_len)
 {
   (void)context;
-  usb_init();
-  int res;
-  // usb_find_busses will find all of the busses on the system. Returns the
-  // number of changes since previous call to this function (total of new
-  // busses and busses removed).
-  if ((res = usb_find_busses()) < 0) {
-    log_put(LOG_GROUP, LOG_CATEGORY, NFC_LOG_PRIORITY_ERROR, "Unable to find USB busses (%s)", _usb_strerror(res));
-    return 0;
-  }
-  // usb_find_devices will find all of the devices on each bus. This should be
-  // called after usb_find_busses. Returns the number of changes since the
-  // previous call to this function (total of new device and devices removed).
-  if ((res = usb_find_devices()) < 0) {
-    log_put(LOG_GROUP, LOG_CATEGORY, NFC_LOG_PRIORITY_ERROR, "Unable to find USB devices (%s)", _usb_strerror(res));
-    return 0;
-  }
-
+  usb_prepare();
   size_t device_found = 0;
   uint32_t uiBusIndex = 0;
   struct usb_bus *bus;
@@ -227,7 +199,7 @@ pn53x_usb_scan(const nfc_context *context, nfc_connstring connstrings[], const s
           usb_dev_handle *udev = usb_open(dev);
 
           // Set configuration
-          res = usb_set_configuration(udev, 1);
+          int res = usb_set_configuration(udev, 1);
           if (res < 0) {
             log_put(LOG_GROUP, LOG_CATEGORY, NFC_LOG_PRIORITY_ERROR, "Unable to set USB configuration (%s)", _usb_strerror(res));
             usb_close(udev);
@@ -330,23 +302,7 @@ pn53x_usb_open(const nfc_context *context, const nfc_connstring connstring)
   struct usb_bus *bus;
   struct usb_device *dev;
 
-  usb_init();
-
-  int res;
-  // usb_find_busses will find all of the busses on the system. Returns the
-  // number of changes since previous call to this function (total of new
-  // busses and busses removed).
-  if ((res = usb_find_busses()) < 0) {
-    log_put(LOG_GROUP, LOG_CATEGORY, NFC_LOG_PRIORITY_ERROR, "Unable to find USB busses (%s)", _usb_strerror(res));
-    goto free_mem;
-  }
-  // usb_find_devices will find all of the devices on each bus. This should be
-  // called after usb_find_busses. Returns the number of changes since the
-  // previous call to this function (total of new device and devices removed).
-  if ((res = usb_find_devices()) < 0) {
-    log_put(LOG_GROUP, LOG_CATEGORY, NFC_LOG_PRIORITY_ERROR, "Unable to find USB devices (%s)", _usb_strerror(res));
-    goto free_mem;
-  }
+  usb_prepare();
 
   for (bus = usb_get_busses(); bus; bus = bus->next) {
     if (connstring_decode_level > 1)  {
@@ -365,7 +321,7 @@ pn53x_usb_open(const nfc_context *context, const nfc_connstring connstring)
       // Retrieve end points
       pn53x_usb_get_end_points(dev, &data);
       // Set configuration
-      res = usb_set_configuration(data.pudh, 1);
+      int res = usb_set_configuration(data.pudh, 1);
       if (res < 0) {
         log_put(LOG_GROUP, LOG_CATEGORY, NFC_LOG_PRIORITY_ERROR, "Unable to set USB configuration (%s)", _usb_strerror(res));
         if (EPERM == -res) {