1 files changed, 12 insertions, 30 deletions

diff --git a/drivers/staging/comedi/drivers/pcl711.c b/drivers/staging/comedi/drivers/pcl711.c
index 40f9136f0bb6..47f4887108a7 100644
--- a/drivers/staging/comedi/drivers/pcl711.c
+++ b/drivers/staging/comedi/drivers/pcl711.c
@@ -157,7 +157,6 @@ static const struct pcl711_board boardtypes[] = {
 
 struct pcl711_private {
 	unsigned int ntrig;
-	unsigned int ao_readback[2];
 	unsigned int divisor1;
 	unsigned int divisor2;
 };
@@ -335,7 +334,9 @@ static int pcl711_ai_cmdtest(struct comedi_device *dev,
 	err |= cfc_check_trigger_arg_is(&cmd->convert_arg, 0);
 	err |= cfc_check_trigger_arg_is(&cmd->scan_end_arg, cmd->chanlist_len);
 
-	if (cmd->stop_src == TRIG_NONE)
+	if (cmd->stop_src == TRIG_COUNT)
+		err |= cfc_check_trigger_arg_min(&cmd->stop_arg, 1);
+	else	/* TRIG_NONE */
 		err |= cfc_check_trigger_arg_is(&cmd->stop_arg, 0);
 
 	if (err)
@@ -377,15 +378,8 @@ static int pcl711_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
 
 	pcl711_set_changain(dev, s, cmd->chanlist[0]);
 
-	if (cmd->stop_src == TRIG_COUNT) {
-		if (cmd->stop_arg == 0) {
-			/* an empty acquisition */
-			s->async->events |= COMEDI_CB_EOA;
-			comedi_event(dev, s);
-			return 0;
-		}
+	if (cmd->stop_src == TRIG_COUNT)
 		devpriv->ntrig = cmd->stop_arg;
-	}
 
 	if (cmd->scan_begin_src == TRIG_TIMER) {
 		pcl711_ai_load_counters(dev);
@@ -410,31 +404,15 @@ static int pcl711_ao_insn_write(struct comedi_device *dev,
 				struct comedi_insn *insn,
 				unsigned int *data)
 {
-	struct pcl711_private *devpriv = dev->private;
 	unsigned int chan = CR_CHAN(insn->chanspec);
-	unsigned int val = devpriv->ao_readback[chan];
+	unsigned int val = s->readback[chan];
 	int i;
 
 	for (i = 0; i < insn->n; i++) {
 		val = data[i];
 		pcl711_ao_write(dev, chan, val);
 	}
-	devpriv->ao_readback[chan] = val;
-
-	return insn->n;
-}
-
-static int pcl711_ao_insn_read(struct comedi_device *dev,
-			       struct comedi_subdevice *s,
-			       struct comedi_insn *insn,
-			       unsigned int *data)
-{
-	struct pcl711_private *devpriv = dev->private;
-	unsigned int chan = CR_CHAN(insn->chanspec);
-	int i;
-
-	for (i = 0; i < insn->n; i++)
-		data[i] = devpriv->ao_readback[chan];
+	s->readback[chan] = val;
 
 	return insn->n;
 }
@@ -476,7 +454,7 @@ static int pcl711_do_insn_bits(struct comedi_device *dev,
 
 static int pcl711_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 {
-	const struct pcl711_board *board = comedi_board(dev);
+	const struct pcl711_board *board = dev->board_ptr;
 	struct pcl711_private *devpriv;
 	struct comedi_subdevice *s;
 	int ret;
@@ -527,7 +505,11 @@ static int pcl711_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 	s->maxdata	= 0xfff;
 	s->range_table	= &range_bipolar5;
 	s->insn_write	= pcl711_ao_insn_write;
-	s->insn_read	= pcl711_ao_insn_read;
+	s->insn_read	= comedi_readback_insn_read;
+
+	ret = comedi_alloc_subdev_readback(s);
+	if (ret)
+		return ret;
 
 	/* Digital Input subdevice */
 	s = &dev->subdevices[2];