staging: comedi: pcmmio: simplify pcmmio_dio_insn_config()

Currently this function uses the subdevice private data to get the
iobase address needed to update the channel configuration. This
subdevice private data is in the process of being removed.

Use the subdevice 'index' to determine the base 'port' needed to
access the correct digital i/o registers. The pcmmio_dio_write()
function can then be used to update the configuration.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/pcmmio.c

@@ -348,24 +348,16 @@ static int pcmmio_dio_insn_config(struct comedi_device *dev,
 				  struct comedi_insn *insn,
 				  unsigned int *data)
 {
-	struct pcmmio_subdev_private *subpriv = s->private;
-	unsigned int chan = CR_CHAN(insn->chanspec);
-	int byte_no = chan / 8;
-	int bit_no = chan % 8;
+	/* subdevice 2 uses ports 0-2, subdevice 3 uses ports 3-5 */
+	int port = s->index == 2 ? 0 : 3;
 	int ret;
 
 	ret = comedi_dio_insn_config(dev, s, insn, data, 0);
 	if (ret)
 		return ret;
 
-	if (data[0] == INSN_CONFIG_DIO_INPUT) {
-		unsigned long ioaddr = subpriv->iobases[byte_no];
-		unsigned char val;
-
-		val = inb(ioaddr);
-		val &= ~(1 << bit_no);
-		outb(val, ioaddr);
-	}
+	if (data[0] == INSN_CONFIG_DIO_INPUT)
+		pcmmio_dio_write(dev, s->io_bits, 0, port);
 
 	return insn->n;
 }