Use the comedi_range_is_bipolar() and comedi_offset_munge() helpers to
munge the bipolar analog input data.
Signed-off-by: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>
Cc: Ian Abbott <abbotti@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/staging/comedi/drivers/pcmmio.c | 22 +++++++++-------------
1 file changed, 9 insertions(+), 13 deletions(-)
diff --git a/drivers/staging/comedi/drivers/pcmmio.c b/drivers/staging/comedi/drivers/pcmmio.c
index 9394782..eb61395 100644
--- a/drivers/staging/comedi/drivers/pcmmio.c
+++ b/drivers/staging/comedi/drivers/pcmmio.c
@@ -785,7 +785,7 @@ static int ai_rinsn(struct comedi_device *dev, struct comedi_subdevice *s,
CR_RANGE(insn->chanspec), aref = CR_AREF(insn->chanspec);
unsigned char command_byte = 0;
unsigned iooffset = 0;
- unsigned short sample, adc_adjust = 0;
+ unsigned int val;
if (chan > 7)
chan -= 8, iooffset = 4; /*
@@ -800,14 +800,6 @@ static int ai_rinsn(struct comedi_device *dev, struct comedi_subdevice *s,
* single-ended
*/
}
- if (range < 2)
- adc_adjust = 0x8000; /*
- * bipolar ranges
- * (-5,5 .. -10,10 need to be
- * adjusted -- that is.. they
- * need to wrap around by
- * adding 0x8000
- */
if (chan % 2) {
command_byte |= 1 << 6; /*
@@ -835,12 +827,16 @@ static int ai_rinsn(struct comedi_device *dev, struct comedi_subdevice *s,
adc_wait_ready(iobase + iooffset);
/* read data lo byte */
- sample = inb(iobase + iooffset + 0);
+ val = inb(iobase + iooffset + 0);
/* read data hi byte */
- sample |= inb(iobase + iooffset + 1) << 8;
- sample += adc_adjust; /* adjustment .. munge data */
- data[n] = sample;
+ val |= inb(iobase + iooffset + 1) << 8;
+
+ /* bipolar data is two's complement */
+ if (comedi_range_is_bipolar(s, range))
+ val = comedi_offset_munge(s, val);
+
+ data[n] = val;
}
/* return the number of samples read/written */
return n;
--
1.8.4.4
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