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staging: comedi: pcmmio: use core helpers to munge bipolar ai data

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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@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
H Hartley Sweeten
2013-12-09 15:30:40 -07:00
committed by Greg Kroah-Hartman
parent f9ec4efd3c
commit 5fde07640c
1 changed files with 9 additions and 13 deletions
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22
drivers/staging/comedi/drivers/pcmmio.c
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@@ -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;