struct diosubd_data {
        int chans;              /*  num of chans or 8255 devices */
-       int addr;               /*  PCI address ofset */
+       unsigned long addr;     /*  PCI address ofset */
 };
 
 struct dio_boardtype {
                                  struct comedi_insn *insn,
                                  unsigned int *data)
 {
-       const struct diosubd_data *d = (const struct diosubd_data *)s->private;
-       unsigned long iobase = dev->iobase + d->addr;
+       unsigned long reg = (unsigned long)s->private;
+       unsigned long iobase = dev->iobase + reg;
 
        data[1] = inb(iobase);
        if (s->n_chan > 8)
                                  struct comedi_insn *insn,
                                  unsigned int *data)
 {
-       const struct diosubd_data *d = (const struct diosubd_data *)s->private;
-       unsigned long iobase = dev->iobase + d->addr;
+       unsigned long reg = (unsigned long)s->private;
+       unsigned long iobase = dev->iobase + reg;
 
        data[1] = inw(iobase);
        if (s->n_chan > 16)
                                  struct comedi_insn *insn,
                                  unsigned int *data)
 {
-       const struct diosubd_data *d = (const struct diosubd_data *)s->private;
-       unsigned long iobase = dev->iobase + d->addr;
+       unsigned long reg = (unsigned long)s->private;
+       unsigned long iobase = dev->iobase + reg;
 
        if (comedi_dio_update_state(s, data)) {
                outb(s->state & 0xff, iobase);
                                  struct comedi_insn *insn,
                                  unsigned int *data)
 {
-       const struct diosubd_data *d = (const struct diosubd_data *)s->private;
-       unsigned long iobase = dev->iobase + d->addr;
+       unsigned long reg = (unsigned long)s->private;
+       unsigned long iobase = dev->iobase + reg;
 
        if (comedi_dio_update_state(s, data)) {
                outw(s->state & 0xffff, iobase);
                        s->insn_bits    = board->is_16bit
                                                ? pci_dio_insn_bits_di_w
                                                : pci_dio_insn_bits_di_b;
-                       s->private      = (void *)d;
+                       s->private      = (void *)d->addr;
                }
        }
 
                        s->insn_bits    = board->is_16bit
                                                ? pci_dio_insn_bits_do_w
                                                : pci_dio_insn_bits_do_b;
-                       s->private      = (void *)d;
+                       s->private      = (void *)d->addr;
                }
        }
 
                s->range_table  = &range_digital;
                s->insn_bits    = board->is_16bit ? pci_dio_insn_bits_di_w
                                                  : pci_dio_insn_bits_di_b;
-               s->private      = (void *)d;
+               s->private      = (void *)d->addr;
        }
 
        if (board->timer_regbase) {