Use the comedi_subdevice 'readback' member and the core provided (*insn_read)
to handle the readback of the write-only caldac subdevice. Remove the then
unused
'caldac' member from the private data.
Tidy up atao_calib_insn_write().
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/ni_at_ao.c | 55 ++++++++++++-------------------
1 file changed, 21 insertions(+), 34 deletions(-)
diff --git a/drivers/staging/comedi/drivers/ni_at_ao.c
b/drivers/staging/comedi/drivers/ni_at_ao.c
index 5fb40cd..05370a4 100644
--- a/drivers/staging/comedi/drivers/ni_at_ao.c
+++ b/drivers/staging/comedi/drivers/ni_at_ao.c
@@ -244,47 +244,31 @@ static int atao_calib_insn_write(struct comedi_device
*dev,
struct comedi_insn *insn,
unsigned int *data)
{
- struct atao_private *devpriv = dev->private;
unsigned int chan = CR_CHAN(insn->chanspec);
- unsigned int bitstring;
- unsigned int val;
- int bit;
- if (insn->n == 0)
- return 0;
+ if (insn->n) {
+ unsigned int val = data[insn->n - 1];
+ unsigned int bitstring = ((chan & 0x7) << 8) | val;
+ unsigned int bits;
+ int bit;
- devpriv->caldac[chan] = data[insn->n - 1] & s->maxdata;
+ /* write the channel and last data value to the caldac */
+ /* clock the bitstring to the caldac; MSB -> LSB */
+ for (bit = 1 << 10; bit; bit >>= 1) {
+ bits = (bit & bitstring) ? ATAO_CFG2_SDATA : 0;
- /* write the channel and last data value to the caldac */
- bitstring = ((chan & 0x7) << 8) | devpriv->caldac[chan];
+ outw(bits, dev->iobase + ATAO_CFG2_REG);
+ outw(bits | ATAO_CFG2_SCLK,
+ dev->iobase + ATAO_CFG2_REG);
+ }
- /* clock the bitstring to the caldac; MSB -> LSB */
- for (bit = 1 << 10; bit; bit >>= 1) {
- val = (bit & bitstring) ? ATAO_CFG2_SDATA : 0;
+ /* strobe the caldac to load the value */
+ outw(ATAO_CFG2_CALLD(chan), dev->iobase + ATAO_CFG2_REG);
+ outw(ATAO_CFG2_CALLD_NOP, dev->iobase + ATAO_CFG2_REG);
- outw(val, dev->iobase + ATAO_CFG2_REG);
- outw(val | ATAO_CFG2_SCLK, dev->iobase + ATAO_CFG2_REG);
+ s->readback[chan] = val;
}
- /* strobe the caldac to load the value */
- outw(ATAO_CFG2_CALLD(chan), dev->iobase + ATAO_CFG2_REG);
- outw(ATAO_CFG2_CALLD_NOP, dev->iobase + ATAO_CFG2_REG);
-
- return insn->n;
-}
-
-static int atao_calib_insn_read(struct comedi_device *dev,
- struct comedi_subdevice *s,
- struct comedi_insn *insn,
- unsigned int *data)
-{
- struct atao_private *devpriv = dev->private;
- unsigned int chan = CR_CHAN(insn->chanspec);
- int i;
-
- for (i = 0; i < insn->n; i++)
- data[i] = devpriv->caldac[chan];
-
return insn->n;
}
@@ -365,9 +349,12 @@ static int atao_attach(struct comedi_device *dev, struct
comedi_devconfig *it)
s->subdev_flags = SDF_WRITABLE | SDF_INTERNAL;
s->n_chan = (board->n_ao_chans * 2) + 1;
s->maxdata = 0xff;
- s->insn_read = atao_calib_insn_read;
s->insn_write = atao_calib_insn_write;
+ ret = comedi_alloc_subdev_readback(s);
+ if (ret)
+ return ret;
+
/* EEPROM subdevice */
s = &dev->subdevices[3];
s->type = COMEDI_SUBD_UNUSED;
--
2.0.3
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