staging: comedi: pcl812: consolidate the common interrupt code

The DMA and EOC interrupt handler functions, that are called by the
_real_ interrupt function, always return IRQ_HANDLED. Change the
return type for these functions to void and move the final return to
the real interrupt function.

Change the parameters to the handler functions to the comedi_device and
comedi_subdevice pointers.

At some point in the handler functions the interrupt request is cleared.
Move this to the real interrupt function.

Also at some point in the handlers, comedi_event() is called to pass any
events to the comedi subsystem. Move this to the real interrupt function
also.

For aesthetics, and to clarify the code, rename the interrupt function and
the handler functions.
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/pcl812.c

@@ -905,17 +905,15 @@ static bool pcl812_ai_next_chan(struct comedi_device *dev,
 		/* 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_pcl812_ai_int(int irq, void *d)
+static void pcl812_handle_eoc(struct comedi_device *dev,
+			      struct comedi_subdevice *s)
 {
-	struct comedi_device *dev = d;
-	struct comedi_subdevice *s = dev->read_subdev;
 	struct comedi_cmd *cmd = &s->async->cmd;
 	unsigned int next_chan;
 
@@ -923,8 +921,7 @@ static irqreturn_t interrupt_pcl812_ai_int(int irq, void *d)
 		dev_dbg(dev->class_dev, "A/D cmd IRQ without DRDY!\n");
 		s->cancel(dev, s);
 		s->async->events |= COMEDI_CB_EOA | COMEDI_CB_ERROR;
-		comedi_event(dev, s);
-		return IRQ_HANDLED;
+		return;
 	}
 
 	comedi_buf_put(s->async, pcl812_ai_get_sample(dev, s));
@@ -936,13 +933,7 @@ static irqreturn_t interrupt_pcl812_ai_int(int irq, void *d)
 	if (cmd->chanlist[s->async->cur_chan] != cmd->chanlist[next_chan])
 		setup_range_channel(dev, s, cmd->chanlist[next_chan], 0);
 
-	outb(0, dev->iobase + PCL812_CLRINT);	/* clear INT request */
-
-	if (!pcl812_ai_next_chan(dev, s))
-		return IRQ_HANDLED;
-
-	comedi_event(dev, s);
-	return IRQ_HANDLED;
+	pcl812_ai_next_chan(dev, s);
 }
 
 static void transfer_from_dma_buf(struct comedi_device *dev,
@@ -953,21 +944,17 @@ static void transfer_from_dma_buf(struct comedi_device *dev,
 	unsigned int i;
 
 	for (i = len; i; i--) {
-							/*  get one sample */
 		comedi_buf_put(s->async, ptr[bufptr++]);
 
 		if (!pcl812_ai_next_chan(dev, s))
-			return;
+			break;
 	}
-
-	comedi_event(dev, s);
 }
 
-static irqreturn_t interrupt_pcl812_ai_dma(int irq, void *d)
+static void pcl812_handle_dma(struct comedi_device *dev,
+			      struct comedi_subdevice *s)
 {
-	struct comedi_device *dev = d;
 	struct pcl812_private *devpriv = dev->private;
-	struct comedi_subdevice *s = dev->read_subdev;
 	int len, bufptr;
 	unsigned short *ptr;
 
@@ -977,29 +964,32 @@ static irqreturn_t interrupt_pcl812_ai_dma(int irq, void *d)
 
 	pcl812_ai_setup_next_dma(dev, s);
 
-	outb(0, dev->iobase + PCL812_CLRINT);	/* clear INT request */
-
 	bufptr = devpriv->ai_poll_ptr;
 	devpriv->ai_poll_ptr = 0;
 
 	transfer_from_dma_buf(dev, s, ptr, bufptr, len);
-
-	return IRQ_HANDLED;
 }
 
-static irqreturn_t interrupt_pcl812(int irq, void *d)
+static irqreturn_t pcl812_interrupt(int irq, void *d)
 {
 	struct comedi_device *dev = d;
+	struct comedi_subdevice *s = dev->read_subdev;
 	struct pcl812_private *devpriv = dev->private;
 
 	if (!dev->attached) {
 		outb(0, dev->iobase + PCL812_CLRINT);
 		return IRQ_HANDLED;
 	}
+
 	if (devpriv->ai_dma)
-		return interrupt_pcl812_ai_dma(irq, d);
+		pcl812_handle_dma(dev, s);
 	else
-		return interrupt_pcl812_ai_int(irq, d);
+		pcl812_handle_eoc(dev, s);
+
+	outb(0, dev->iobase + PCL812_CLRINT);
+
+	comedi_event(dev, s);
+	return IRQ_HANDLED;
 }
 
 static int pcl812_ai_poll(struct comedi_device *dev, struct comedi_subdevice *s)
@@ -1248,7 +1238,7 @@ static int pcl812_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 		return ret;
 
 	if ((1 << it->options[1]) & board->IRQbits) {
-		ret = request_irq(it->options[1], interrupt_pcl812, 0,
+		ret = request_irq(it->options[1], pcl812_interrupt, 0,
 				  dev->board_name, dev);
 		if (ret == 0)
 			dev->irq = it->options[1];