Use the comedi_offset_munge() helper to do the offset binary to two's
complement conversion when writing a new analog output value.
Signed-off-by: H Hartley Sweeten <hswee...@visionengravers.com>
Cc: Ian Abbott <abbo...@mev.co.uk>
Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
drivers/staging/comedi/drivers/quatech_daqp_cs.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)
diff --git a/drivers/staging/comedi/drivers/quatech_daqp_cs.c
b/drivers/staging/comedi/drivers/quatech_daqp_cs.c
index 23c79e3..9514544 100644
--- a/drivers/staging/comedi/drivers/quatech_daqp_cs.c
+++ b/drivers/staging/comedi/drivers/quatech_daqp_cs.c
@@ -594,11 +594,9 @@ static int daqp_ao_insn_write(struct comedi_device *dev,
s->readback[chan] = val;
- val &= 0x0fff;
- val ^= 0x0800; /* Flip the sign */
- val |= (chan << 12);
-
- outw(val, dev->iobase + DAQP_DA);
+ /* write the two's complement value to the channel */
+ outw((chan << 12) | comedi_offset_munge(s, val),
+ dev->iobase + DAQP_DA);
}
return insn->n;
--
2.5.1
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