* one sub device just now: A/D
  */
 struct usbduxfast_private {
-       struct usb_device *usb; /* pointer to the usb-device */
        struct urb *urbIn;      /* BULK-transfer handling: urb */
        int8_t *transfer_buffer;
        int16_t *insnBuffer;    /* input buffer for single insn */
 
 static int send_dux_commands(struct comedi_device *dev, int cmd_type)
 {
+       struct usb_interface *intf = comedi_to_usb_interface(dev);
+       struct usb_device *usb = interface_to_usbdev(intf);
        struct usbduxfast_private *devpriv = dev->private;
        int tmp, nsent;
 
        devpriv->dux_commands[0] = cmd_type;
 
-       tmp = usb_bulk_msg(devpriv->usb,
-                          usb_sndbulkpipe(devpriv->usb, CHANNELLISTEP),
+       tmp = usb_bulk_msg(usb, usb_sndbulkpipe(usb, CHANNELLISTEP),
                           devpriv->dux_commands,
                           SIZEOFDUXBUFFER, &nsent, 10000);
        if (tmp < 0)
        struct comedi_device *dev = urb->context;
        struct comedi_subdevice *s = dev->read_subdev;
        struct comedi_async *async = s->async;
+       struct usb_interface *intf = comedi_to_usb_interface(dev);
+       struct usb_device *usb = interface_to_usbdev(intf);
        struct usbduxfast_private *devpriv = dev->private;
        int n, err;
 
         * command is still running
         * resubmit urb for BULK transfer
         */
-       urb->dev = devpriv->usb;
+       urb->dev = usb;
        urb->status = 0;
        err = usb_submit_urb(urb, GFP_ATOMIC);
        if (err < 0) {
 
 static int usbduxfastsub_start(struct comedi_device *dev)
 {
-       struct usbduxfast_private *devpriv = dev->private;
+       struct usb_interface *intf = comedi_to_usb_interface(dev);
+       struct usb_device *usb = interface_to_usbdev(intf);
        unsigned char *local_transfer_buffer;
        int ret;
 
        /* 7f92 to zero */
        *local_transfer_buffer = 0;
        /* bRequest, "Firmware" */
-       ret = usb_control_msg(devpriv->usb, usb_sndctrlpipe(devpriv->usb, 0),
+       ret = usb_control_msg(usb, usb_sndctrlpipe(usb, 0),
                              USBDUXFASTSUB_FIRMWARE,
                              VENDOR_DIR_OUT,     /* bmRequestType */
                              USBDUXFASTSUB_CPUCS,    /* Value */
 
 static int usbduxfastsub_stop(struct comedi_device *dev)
 {
-       struct usbduxfast_private *devpriv = dev->private;
+       struct usb_interface *intf = comedi_to_usb_interface(dev);
+       struct usb_device *usb = interface_to_usbdev(intf);
        unsigned char *local_transfer_buffer;
        int ret;
 
        /* 7f92 to one */
        *local_transfer_buffer = 1;
        /* bRequest, "Firmware" */
-       ret = usb_control_msg(devpriv->usb, usb_sndctrlpipe(devpriv->usb, 0),
+       ret = usb_control_msg(usb, usb_sndctrlpipe(usb, 0),
                              USBDUXFASTSUB_FIRMWARE,
                              VENDOR_DIR_OUT,   /* bmRequestType */
                              USBDUXFASTSUB_CPUCS,      /* Value */
                                unsigned char *local_transfer_buffer,
                                unsigned int startAddr, unsigned int len)
 {
-       struct usbduxfast_private *devpriv = dev->private;
+       struct usb_interface *intf = comedi_to_usb_interface(dev);
+       struct usb_device *usb = interface_to_usbdev(intf);
        int ret;
 
        /* brequest, firmware */
-       ret = usb_control_msg(devpriv->usb, usb_sndctrlpipe(devpriv->usb, 0),
+       ret = usb_control_msg(usb, usb_sndctrlpipe(usb, 0),
                              USBDUXFASTSUB_FIRMWARE,
                              VENDOR_DIR_OUT,   /* bmRequestType */
                              startAddr,        /* value */
 
 static int usbduxfastsub_submit_InURBs(struct comedi_device *dev)
 {
+       struct usb_interface *intf = comedi_to_usb_interface(dev);
+       struct usb_device *usb = interface_to_usbdev(intf);
        struct usbduxfast_private *devpriv = dev->private;
        int ret;
 
        if (!devpriv)
                return -EFAULT;
 
-       usb_fill_bulk_urb(devpriv->urbIn, devpriv->usb,
-                         usb_rcvbulkpipe(devpriv->usb, BULKINEP),
+       usb_fill_bulk_urb(devpriv->urbIn, usb, usb_rcvbulkpipe(usb, BULKINEP),
                          devpriv->transfer_buffer, SIZEINBUF,
                          usbduxfast_ai_interrupt, dev);
 
                                   struct comedi_subdevice *s,
                                   struct comedi_insn *insn, unsigned int *data)
 {
+       struct usb_interface *intf = comedi_to_usb_interface(dev);
+       struct usb_device *usb = interface_to_usbdev(intf);
        struct usbduxfast_private *devpriv = dev->private;
        int i, j, n, actual_length;
        int chan, range, rngmask;
        }
 
        for (i = 0; i < PACKETS_TO_IGNORE; i++) {
-               err = usb_bulk_msg(devpriv->usb,
-                                  usb_rcvbulkpipe(devpriv->usb, BULKINEP),
+               err = usb_bulk_msg(usb, usb_rcvbulkpipe(usb, BULKINEP),
                                   devpriv->transfer_buffer, SIZEINBUF,
                                   &actual_length, 10000);
                if (err < 0) {
        }
        /* data points */
        for (i = 0; i < insn->n;) {
-               err = usb_bulk_msg(devpriv->usb,
-                                  usb_rcvbulkpipe(devpriv->usb, BULKINEP),
+               err = usb_bulk_msg(usb, usb_rcvbulkpipe(usb, BULKINEP),
                                   devpriv->transfer_buffer, SIZEINBUF,
                                   &actual_length, 10000);
                if (err < 0) {
        dev->private = devpriv;
 
        sema_init(&devpriv->sem, 1);
-       devpriv->usb = usb;
        usb_set_intfdata(intf, devpriv);
 
        devpriv->dux_commands = kmalloc(SIZEOFDUXBUFFER, GFP_KERNEL);
        if (!devpriv->insnBuffer)
                return -ENOMEM;
 
-       ret = usb_set_interface(devpriv->usb,
+       ret = usb_set_interface(usb,
                                intf->altsetting->desc.bInterfaceNumber, 1);
        if (ret < 0) {
                dev_err(dev->class_dev,