staging: comedi: ni_atmio16d: use comedi_timeout()

Use comedi_timeout() to wait for the analog input end-of-conversion.

Change the errno returned when the conversion overflows from -ETIME
to -EOVERFLOW.
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/ni_atmio16d.c

@@ -96,7 +96,6 @@ Devices: [National Instruments] AT-MIO-16 (atmio16), AT-MIO-16D (atmio16d)
 #define CLOCK_100_HZ	0x8F25
 /* Other miscellaneous defines */
 #define ATMIO16D_SIZE	32	/* bus address range */
-#define ATMIO16D_TIMEOUT 10
 
 struct atmio16_board_t {
 
@@ -448,16 +447,32 @@ static int atmio16d_ai_cancel(struct comedi_device *dev,
 	return 0;
 }
 
-/* Mode 0 is used to get a single conversion on demand */
+static int atmio16d_ai_eoc(struct comedi_device *dev,
+			   struct comedi_subdevice *s,
+			   struct comedi_insn *insn,
+			   unsigned long context)
+{
+	unsigned int status;
+
+	status = inw(dev->iobase + STAT_REG);
+	if (status & STAT_AD_CONVAVAIL)
+		return 0;
+	if (status & STAT_AD_OVERFLOW) {
+		outw(0, dev->iobase + AD_CLEAR_REG);
+		return -EOVERFLOW;
+	}
+	return -EBUSY;
+}
+
 static int atmio16d_ai_insn_read(struct comedi_device *dev,
 				 struct comedi_subdevice *s,
 				 struct comedi_insn *insn, unsigned int *data)
 {
 	struct atmio16d_private *devpriv = dev->private;
-	int i, t;
+	int i;
 	int chan;
 	int gain;
-	int status;
+	int ret;
 
 	chan = CR_CHAN(insn->chanspec);
 	gain = CR_RANGE(insn->chanspec);
@@ -473,26 +488,17 @@ static int atmio16d_ai_insn_read(struct comedi_device *dev,
 	for (i = 0; i < insn->n; i++) {
 		/* start the conversion */
 		outw(0, dev->iobase + START_CONVERT_REG);
+
 		/* wait for it to finish */
-		for (t = 0; t < ATMIO16D_TIMEOUT; t++) {
-			/* check conversion status */
-			status = inw(dev->iobase + STAT_REG);
-			if (status & STAT_AD_CONVAVAIL) {
+		ret = comedi_timeout(dev, s, insn, atmio16d_ai_eoc, 0);
+		if (ret)
+			return ret;
+
 		/* read the data now */
 		data[i] = inw(dev->iobase + AD_FIFO_REG);
 		/* change to two's complement if need be */
 		if (devpriv->adc_coding == adc_2comp)
 			data[i] ^= 0x800;
-				break;
-			}
-			if (status & STAT_AD_OVERFLOW) {
-				outw(0, dev->iobase + AD_CLEAR_REG);
-				return -ETIME;
-			}
-		}
-		/* end waiting, now check if it timed out */
-		if (t == ATMIO16D_TIMEOUT)
-			return -ETIME;
 	}
 
 	return i;