[PATCH 41/87] staging: comedi: pcl816: introduce pcl816_ai_get_sample()

[H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>]

Introduce a helper function to read the 14/16-bit analog input data
sample.

Signed-off-by: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>
Cc: Ian Abbott <abbotti@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/staging/comedi/drivers/pcl816.c | 26 +++++++++++++++-----------
 1 file changed, 15 insertions(+), 11 deletions(-)

diff --git a/drivers/staging/comedi/drivers/pcl816.c b/drivers/staging/comedi/drivers/pcl816.c
index 0337a13..fde0989 100644
--- a/drivers/staging/comedi/drivers/pcl816.c
+++ b/drivers/staging/comedi/drivers/pcl816.c
@@ -153,6 +153,17 @@ static int pcl816_ai_cmdtest(struct comedi_device *dev,
 			     struct comedi_cmd *cmd);
 static int pcl816_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s);
 
+static unsigned int pcl816_ai_get_sample(struct comedi_device *dev,
+					 struct comedi_subdevice *s)
+{
+	unsigned int val;
+
+	val = inb(dev->iobase + PCL816_AD_HI) << 8;
+	val |= inb(dev->iobase + PCL816_AD_LO);
+
+	return val & s->maxdata;
+}
+
 static int pcl816_ai_eoc(struct comedi_device *dev,
 			 struct comedi_subdevice *s,
 			 struct comedi_insn *insn,
@@ -194,9 +205,8 @@ static int pcl816_ai_insn_read(struct comedi_device *dev,
 			return ret;
 		}
 
-		/*  return read value */
-		data[n] = ((inb(dev->iobase + PCL816_AD_HI) << 8) |
-			  (inb(dev->iobase + PCL816_AD_LO)));
+		data[n] = pcl816_ai_get_sample(dev, s);
+
 		/* clear INT (conversion end) flag */
 		outb(0, dev->iobase + PCL816_CLRINT);
 	}
@@ -213,7 +223,6 @@ static irqreturn_t interrupt_pcl816_ai_mode13_int(int irq, void *d)
 	struct comedi_device *dev = d;
 	struct pcl816_private *devpriv = dev->private;
 	struct comedi_subdevice *s = dev->read_subdev;
-	unsigned char low, hi;
 	int timeout = 50;	/* wait max 50us */
 
 	while (timeout--) {
@@ -232,11 +241,7 @@ static irqreturn_t interrupt_pcl816_ai_mode13_int(int irq, void *d)
 
 	}
 
-	/*  get the sample */
-	low = inb(dev->iobase + PCL816_AD_LO);
-	hi = inb(dev->iobase + PCL816_AD_HI);
-
-	comedi_buf_put(s->async, (hi << 8) | low);
+	comedi_buf_put(s->async, pcl816_ai_get_sample(dev, s));
 
 	outb(0, dev->iobase + PCL816_CLRINT);	/* clear INT request */
 
@@ -640,8 +645,7 @@ static int pcl816_ai_cancel(struct comedi_device *dev,
 			outb(0xb0, dev->iobase + PCL816_CTRCTL);
 			outb(0x70, dev->iobase + PCL816_CTRCTL);
 			outb(0, dev->iobase + PCL816_AD_LO);
-			inb(dev->iobase + PCL816_AD_LO);
-			inb(dev->iobase + PCL816_AD_HI);
+			pcl816_ai_get_sample(dev, s);
 
 			/* clear INT request */
 			outb(0, dev->iobase + PCL816_CLRINT);
-- 
1.8.5.2

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