For aesthetics, rename the function and tidy it up a bit. Also rename the
registers used by this function and add a macro to set the 'chan' bits in
the MSB data register.
Signed-off-by: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>
Cc: Ian Abbott <abbotti@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/staging/comedi/drivers/dmm32at.c | 44 +++++++++++++++-----------------
1 file changed, 20 insertions(+), 24 deletions(-)
diff --git a/drivers/staging/comedi/drivers/dmm32at.c b/drivers/staging/comedi/drivers/dmm32at.c
index e9cd251..cfe3234 100644
--- a/drivers/staging/comedi/drivers/dmm32at.c
+++ b/drivers/staging/comedi/drivers/dmm32at.c
@@ -47,9 +47,10 @@ Configuration Options:
#define DMM32AT_AILOW 0x02
#define DMM32AT_AIHIGH 0x03
-#define DMM32AT_DACLSB 0x04
#define DMM32AT_DACSTAT 0x04
-#define DMM32AT_DACMSB 0x05
+#define DMM32AT_DACLSB_REG 0x04
+#define DMM32AT_DACMSB_REG 0x05
+#define DMM32AT_DACMSB_CHAN(x) ((x) << 6)
#define DMM32AT_FIFOCNTRL 0x07
#define DMM32AT_FIFOSTAT 0x07
@@ -540,42 +541,37 @@ static int dmm32at_ao_eoc(struct comedi_device *dev,
return -EBUSY;
}
-static int dmm32at_ao_winsn(struct comedi_device *dev,
- struct comedi_subdevice *s,
- struct comedi_insn *insn, unsigned int *data)
+static int dmm32at_ao_insn_write(struct comedi_device *dev,
+ struct comedi_subdevice *s,
+ struct comedi_insn *insn,
+ unsigned int *data)
{
struct dmm32at_private *devpriv = dev->private;
- int i;
- int chan = CR_CHAN(insn->chanspec);
- unsigned char hi, lo, status;
+ unsigned int chan = CR_CHAN(insn->chanspec);
+ unsigned int val;
int ret;
+ int i;
- /* Writing a list of values to an AO channel is probably not
- * very useful, but that's how the interface is defined. */
for (i = 0; i < insn->n; i++) {
+ val = data[i];
- devpriv->ao_readback[chan] = data[i];
-
- /* get the low byte */
- lo = data[i] & 0x00ff;
- /* high byte also contains channel number */
- hi = (data[i] >> 8) + chan * (1 << 6);
- /* write the low and high values to the board */
- outb(lo, dev->iobase + DMM32AT_DACLSB);
- outb(hi, dev->iobase + DMM32AT_DACMSB);
+ /* write LSB then MSB + chan to load DAC */
+ outb(val & 0xff, dev->iobase + DMM32AT_DACLSB_REG);
+ outb((val >> 8) | DMM32AT_DACMSB_CHAN(chan),
+ dev->iobase + DMM32AT_DACMSB_REG);
/* wait for circuit to settle */
ret = comedi_timeout(dev, s, insn, dmm32at_ao_eoc, 0);
if (ret)
return ret;
- /* dummy read to update trigger the output */
- status = inb(dev->iobase + DMM32AT_DACMSB);
+ /* dummy read to update DAC */
+ inb(dev->iobase + DMM32AT_DACMSB_REG);
+ devpriv->ao_readback[chan] = val;
}
- /* return the number of samples read/written */
- return i;
+ return insn->n;
}
static int dmm32at_ao_rinsn(struct comedi_device *dev,
@@ -764,7 +760,7 @@ static int dmm32at_attach(struct comedi_device *dev,
s->n_chan = 4;
s->maxdata = 0x0fff;
s->range_table = &dmm32at_aoranges;
- s->insn_write = dmm32at_ao_winsn;
+ s->insn_write = dmm32at_ao_insn_write;
s->insn_read = dmm32at_ao_rinsn;
s = &dev->subdevices[2];
--
2.0.3
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