On the PCI-1720 board, bipolar analog output ranges use two's
complement data. Use comedi_offset_munge() to munge the comedi
offset binary values before writing them to the hardware.
Signed-off-by: H Hartley Sweeten <hswee...@visionengravers.com>
Cc: Ian Abbott <abbo...@mev.co.uk>
Cc: Greg Kroah-Hartman <gr...@linuxfoundation.org>
---
drivers/staging/comedi/drivers/adv_pci1710.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)
diff --git a/drivers/staging/comedi/drivers/adv_pci1710.c
b/drivers/staging/comedi/drivers/adv_pci1710.c
index cb3edf9..c2c5b34 100644
--- a/drivers/staging/comedi/drivers/adv_pci1710.c
+++ b/drivers/staging/comedi/drivers/adv_pci1710.c
@@ -682,26 +682,30 @@ static int pci1720_insn_write_ao(struct comedi_device
*dev,
struct comedi_insn *insn, unsigned int *data)
{
struct pci1710_private *devpriv = dev->private;
+ unsigned int chan = CR_CHAN(insn->chanspec);
+ unsigned int range = CR_RANGE(insn->chanspec);
unsigned int val;
- int n, rangereg, chan;
+ int n, rangereg;
- chan = CR_CHAN(insn->chanspec);
rangereg = devpriv->da_ranges & (~(0x03 << (chan << 1)));
- rangereg |= (CR_RANGE(insn->chanspec) << (chan << 1));
+ rangereg |= (range << (chan << 1));
if (rangereg != devpriv->da_ranges) {
outb(rangereg, dev->iobase + PCI1720_RANGE);
devpriv->da_ranges = rangereg;
}
- val = devpriv->ao_data[chan];
for (n = 0; n < insn->n; n++) {
val = data[n];
+ devpriv->ao_data[chan] = val;
+
+ /* bipolar codes are two's complement values */
+ if (comedi_range_is_bipolar(s, range))
+ val = comedi_offset_munge(s, val);
+
outw(val, dev->iobase + PCI1720_DA0 + (chan << 1));
outb(0, dev->iobase + PCI1720_SYNCOUT); /* update outputs */
}
- devpriv->ao_data[chan] = val;
-
return n;
}
--
1.9.3
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