staging: comedi: dt2801: remove 'boardtype' macro

The 'boardtype' macro relies on a local variable having a specific
name and yields a struct derived from that local variable.

Replace the macro with local variables and use the comedi_board()
helper to get the struct as a pointer. Use pointer access when
using the variable.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/dt2801.c

@@ -225,8 +225,6 @@ static const struct dt2801_board boardtypes[] = {
 	 .dabits = 12},
 };
 
-#define boardtype (*(const struct dt2801_board *)dev->board_ptr)
-
 struct dt2801_private {
 
 	const struct comedi_lrange *dac_range_types[2];
@@ -592,6 +590,7 @@ static int dt2801_dio_insn_config(struct comedi_device *dev,
 */
 static int dt2801_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 {
+	const struct dt2801_board *board = comedi_board(dev);
 	struct dt2801_private *devpriv;
 	struct comedi_subdevice *s;
 	unsigned long iobase;
@@ -624,7 +623,8 @@ static int dt2801_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 
 havetype:
 	dev->board_ptr = boardtypes + type;
-	printk("dt2801: %s at port 0x%lx", boardtype.name, iobase);
+	board = comedi_board(dev);
+	printk("dt2801: %s at port 0x%lx", board->name, iobase);
 
 	n_ai_chans = probe_number_of_ai_chans(dev);
 	printk(" (ai channels = %d)\n", n_ai_chans);
@@ -638,7 +638,7 @@ static int dt2801_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 		return -ENOMEM;
 	dev->private = devpriv;
 
-	dev->board_name = boardtype.name;
+	dev->board_name = board->name;
 
 	s = &dev->subdevices[0];
 	/* ai subdevice */
@@ -648,12 +648,12 @@ static int dt2801_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 	s->n_chan = n_ai_chans;
 #else
 	if (it->options[2])
-		s->n_chan = boardtype.ad_chan;
+		s->n_chan = board->ad_chan;
 	else
-		s->n_chan = boardtype.ad_chan / 2;
+		s->n_chan = board->ad_chan / 2;
 #endif
-	s->maxdata = (1 << boardtype.adbits) - 1;
-	s->range_table = ai_range_lkup(boardtype.adrangetype, it->options[3]);
+	s->maxdata = (1 << board->adbits) - 1;
+	s->range_table = ai_range_lkup(board->adrangetype, it->options[3]);
 	s->insn_read = dt2801_ai_insn_read;
 
 	s = &dev->subdevices[1];
@@ -661,7 +661,7 @@ static int dt2801_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 	s->type = COMEDI_SUBD_AO;
 	s->subdev_flags = SDF_WRITABLE;
 	s->n_chan = 2;
-	s->maxdata = (1 << boardtype.dabits) - 1;
+	s->maxdata = (1 << board->dabits) - 1;
 	s->range_table_list = devpriv->dac_range_types;
 	devpriv->dac_range_types[0] = dac_range_lkup(it->options[4]);
 	devpriv->dac_range_types[1] = dac_range_lkup(it->options[5]);