Index: uspace/lib/drv/include/usbdiag_iface.h
===================================================================
--- uspace/lib/drv/include/usbdiag_iface.h	(revision 1ea0bbf904b247218cfae78b7d3a61582f2a159a)
+++ uspace/lib/drv/include/usbdiag_iface.h	(revision 1ea0bbf904b247218cfae78b7d3a61582f2a159a)
@@ -0,0 +1,57 @@
+/*
+ * Copyright (c) 2017 Petr Manek
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ * - The name of the author may not be used to endorse or promote products
+ *   derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/** @addtogroup libdrv
+* @addtogroup usb
+* @{
+*/
+/** @file
+* @brief USB diagnostic device interface definition.
+*/
+
+#ifndef LIBDRV_USBDIAG_IFACE_H_
+#define LIBDRV_USBDIAG_IFACE_H_
+
+#include <async.h>
+#include "ddf/driver.h"
+
+#define USBDIAG_CATEGORY "usbdiag"
+
+async_sess_t *usbdiag_connect(devman_handle_t);
+void usbdiag_disconnect(async_sess_t*);
+int usbdiag_test(async_exch_t*, int, int*);
+
+/** USB diagnostic device communication interface. */
+typedef struct {
+	int (*test)(ddf_fun_t*, int, int*);
+} usbdiag_iface_t;
+
+#endif
+/**
+ * @}
+ */