For aesthetics, rename this function and tidy it up a bit.
Use the comedi_range_is_bipolar() and comedi_offset_munge() helpers
to handle the 2's complement munging.
Save the readback value after the conversion is complete.
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/rtd520.c | 35 ++++++++++++++++-----------------
1 file changed, 17 insertions(+), 18 deletions(-)
diff --git a/drivers/staging/comedi/drivers/rtd520.c
b/drivers/staging/comedi/drivers/rtd520.c
index 5fe92c4..2df8494 100644
--- a/drivers/staging/comedi/drivers/rtd520.c
+++ b/drivers/staging/comedi/drivers/rtd520.c
@@ -1046,42 +1046,41 @@ static int rtd_ao_eoc(struct comedi_device *dev,
return -EBUSY;
}
-static int rtd_ao_winsn(struct comedi_device *dev,
- struct comedi_subdevice *s, struct comedi_insn *insn,
- unsigned int *data)
+static int rtd_ao_insn_write(struct comedi_device *dev,
+ struct comedi_subdevice *s,
+ struct comedi_insn *insn,
+ unsigned int *data)
{
struct rtd_private *devpriv = dev->private;
- int i;
- int chan = CR_CHAN(insn->chanspec);
- int range = CR_RANGE(insn->chanspec);
+ unsigned int chan = CR_CHAN(insn->chanspec);
+ unsigned int range = CR_RANGE(insn->chanspec);
int ret;
+ int i;
/* Configure the output range (table index matches the range values) */
writew(range & 7, dev->mmio + LAS0_DAC_CTRL(chan));
for (i = 0; i < insn->n; ++i) {
- int val = data[i] << 3;
+ unsigned int val = data[i];
- /* VERIFY: comedi range and offset conversions */
+ /* bipolar ranges use 2's complement values */
+ if (comedi_range_is_bipolar(s, range))
+ val = comedi_offset_munge(s, val);
- if ((range > 1) && (data[i] < 2048)) { /* bipolar */
- /* offset and sign extend */
- val = (((int)data[i]) - 2048) << 3;
- } else { /* unipolor */
- val = data[i] << 3;
- }
+ /* the 12-bit data is left justified to 16-bits */
+ val <<= 3;
writew(val, devpriv->las1 + LAS1_DAC_FIFO(chan));
writew(0, dev->mmio + LAS0_UPDATE_DAC(chan));
- s->readback[chan] = data[i];
-
ret = comedi_timeout(dev, s, insn, rtd_ao_eoc, 0);
if (ret)
return ret;
+
+ s->readback[chan] = data[i];
}
- return i;
+ return insn->n;
}
static int rtd_dio_insn_bits(struct comedi_device *dev,
@@ -1240,7 +1239,7 @@ static int rtd_auto_attach(struct comedi_device *dev,
s->n_chan = 2;
s->maxdata = 0x0fff;
s->range_table = &rtd_ao_range;
- s->insn_write = rtd_ao_winsn;
+ s->insn_write = rtd_ao_insn_write;
ret = comedi_alloc_subdev_readback(s);
if (ret)
--
2.5.1
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