staging: comedi: pcl818: factor out the common "next ai chan" code

The DMA, FIFO, and EOC interrupt handlers all have common code that
bumps the counters in the private data that keep track of what channel
is being sampled next and when all the data has been sampled.

Factor this common code into a helper function.

Make sure the COMEDI_CB_BLOCK event is set when advancing to the next
channel so that when the comedi_event() is finally called the core will
wake the async_queue to return the analog input data.

Also, make sure the COMEDI_CB_EOS event is set at the completion of each
scan.
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/pcl818.c

@@ -540,12 +540,41 @@ static int pcl818_do_insn_bits(struct comedi_device *dev,
 	return insn->n;
 }
 
+static bool pcl818_ai_next_chan(struct comedi_device *dev,
+				struct comedi_subdevice *s)
+{
+	struct pcl818_private *devpriv = dev->private;
+	struct comedi_cmd *cmd = &s->async->cmd;
+
+	s->async->events |= COMEDI_CB_BLOCK;
+
+	devpriv->act_chanlist_pos++;
+	if (devpriv->act_chanlist_pos >= devpriv->act_chanlist_len)
+		devpriv->act_chanlist_pos = 0;
+
+	s->async->cur_chan++;
+	if (s->async->cur_chan >= cmd->chanlist_len) {
+		s->async->cur_chan = 0;
+		devpriv->ai_act_scan--;
+		s->async->events |= COMEDI_CB_EOS;
+	}
+
+	if (cmd->stop_src == TRIG_COUNT && devpriv->ai_act_scan == 0) {
+		/* all data sampled */
+		s->cancel(dev, s);
+		s->async->events |= COMEDI_CB_EOA;
+		comedi_event(dev, s);
+		return false;
+	}
+
+	return true;
+}
+
 static irqreturn_t interrupt_pcl818_ai_mode13_int(int irq, void *d)
 {
 	struct comedi_device *dev = d;
 	struct pcl818_private *devpriv = dev->private;
 	struct comedi_subdevice *s = dev->read_subdev;
-	struct comedi_cmd *cmd = &s->async->cmd;
 	unsigned int chan;
 
 	if (pcl818_ai_eoc(dev, s, NULL, 0)) {
@@ -570,21 +599,10 @@ static irqreturn_t interrupt_pcl818_ai_mode13_int(int irq, void *d)
 		comedi_event(dev, s);
 		return IRQ_HANDLED;
 	}
-	devpriv->act_chanlist_pos++;
-	if (devpriv->act_chanlist_pos >= devpriv->act_chanlist_len)
-		devpriv->act_chanlist_pos = 0;
 
-	s->async->cur_chan++;
-	if (s->async->cur_chan >= cmd->chanlist_len) {
-		s->async->cur_chan = 0;
-		devpriv->ai_act_scan--;
-	}
+	if (!pcl818_ai_next_chan(dev, s))
+		return IRQ_HANDLED;
 
-	if (cmd->stop_src == TRIG_COUNT && devpriv->ai_act_scan == 0) {
-		/* all data sampled */
-		s->cancel(dev, s);
-		s->async->events |= COMEDI_CB_EOA;
-	}
 	comedi_event(dev, s);
 	return IRQ_HANDLED;
 }
@@ -594,7 +612,6 @@ static irqreturn_t interrupt_pcl818_ai_mode13_dma(int irq, void *d)
 	struct comedi_device *dev = d;
 	struct pcl818_private *devpriv = dev->private;
 	struct comedi_subdevice *s = dev->read_subdev;
-	struct comedi_cmd *cmd = &s->async->cmd;
 	int i, len, bufptr;
 	unsigned short *ptr;
 
@@ -621,23 +638,8 @@ static irqreturn_t interrupt_pcl818_ai_mode13_dma(int irq, void *d)
 
 		comedi_buf_put(s->async, ptr[bufptr++] >> 4);	/*  get one sample */
 
-		devpriv->act_chanlist_pos++;
-		if (devpriv->act_chanlist_pos >= devpriv->act_chanlist_len)
-			devpriv->act_chanlist_pos = 0;
-
-		s->async->cur_chan++;
-		if (s->async->cur_chan >= cmd->chanlist_len) {
-			s->async->cur_chan = 0;
-			devpriv->ai_act_scan--;
-		}
-
-		if (cmd->stop_src == TRIG_COUNT && devpriv->ai_act_scan == 0) {
-			/* all data sampled */
-			s->cancel(dev, s);
-			s->async->events |= COMEDI_CB_EOA;
-			comedi_event(dev, s);
+		if (!pcl818_ai_next_chan(dev, s))
 			return IRQ_HANDLED;
-		}
 	}
 
 	if (len > 0)
@@ -650,7 +652,6 @@ static irqreturn_t interrupt_pcl818_ai_mode13_fifo(int irq, void *d)
 	struct comedi_device *dev = d;
 	struct pcl818_private *devpriv = dev->private;
 	struct comedi_subdevice *s = dev->read_subdev;
-	struct comedi_cmd *cmd = &s->async->cmd;
 	int i, len;
 	unsigned char lo;
 
@@ -694,23 +695,8 @@ static irqreturn_t interrupt_pcl818_ai_mode13_fifo(int irq, void *d)
 
 		comedi_buf_put(s->async, (lo >> 4) | (inb(dev->iobase + PCL818_FI_DATAHI) << 4));	/*  get one sample */
 
-		devpriv->act_chanlist_pos++;
-		if (devpriv->act_chanlist_pos >= devpriv->act_chanlist_len)
-			devpriv->act_chanlist_pos = 0;
-
-		s->async->cur_chan++;
-		if (s->async->cur_chan >= cmd->chanlist_len) {
-			s->async->cur_chan = 0;
-			devpriv->ai_act_scan--;
-		}
-
-		if (cmd->stop_src == TRIG_COUNT && devpriv->ai_act_scan == 0) {
-			/* all data sampled */
-			s->cancel(dev, s);
-			s->async->events |= COMEDI_CB_EOA;
-			comedi_event(dev, s);
+		if (!pcl818_ai_next_chan(dev, s))
 			return IRQ_HANDLED;
-		}
 	}
 
 	if (len > 0)