Use the new comedi_subdevice 'readback' member and the core provided
(*insn_read) for the readback of the analog output subdevice channels.
The das08_ao_initialize() function is only called when the subdevice
is first setup during the attach. It is used to initialize the channels
to a known state. Absorb that function to simplify the code a bit.
Signed-off-by: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>
Cc: Ian Abbott <abbotti@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/staging/comedi/drivers/das08.c | 51 ++++++++++++----------------------
drivers/staging/comedi/drivers/das08.h | 1 -
2 files changed, 18 insertions(+), 34 deletions(-)
diff --git a/drivers/staging/comedi/drivers/das08.c b/drivers/staging/comedi/drivers/das08.c
index 9a5a06b..f761a5a 100644
--- a/drivers/staging/comedi/drivers/das08.c
+++ b/drivers/staging/comedi/drivers/das08.c
@@ -338,7 +338,6 @@ static void das08_ao_set_data(struct comedi_device *dev,
unsigned int chan, unsigned int data)
{
const struct das08_board_struct *thisboard = comedi_board(dev);
- struct das08_private_struct *devpriv = dev->private;
unsigned char lsb;
unsigned char msb;
@@ -355,18 +354,6 @@ static void das08_ao_set_data(struct comedi_device *dev,
/* load DACs */
inb(dev->iobase + DAS08AO_AO_UPDATE);
}
- devpriv->ao_readback[chan] = data;
-}
-
-static void das08_ao_initialize(struct comedi_device *dev,
- struct comedi_subdevice *s)
-{
- int n;
- unsigned int data;
-
- data = s->maxdata / 2; /* should be about 0 volts */
- for (n = 0; n < s->n_chan; n++)
- das08_ao_set_data(dev, n, data);
}
static int das08_ao_insn_write(struct comedi_device *dev,
@@ -375,30 +362,18 @@ static int das08_ao_insn_write(struct comedi_device *dev,
unsigned int *data)
{
unsigned int chan = CR_CHAN(insn->chanspec);
+ unsigned int val = s->readback[chan];
int i;
- for (i = 0; i < insn->n; i++)
- das08_ao_set_data(dev, chan, data[i]);
+ for (i = 0; i < insn->n; i++) {
+ val = data[i];
+ das08_ao_set_data(dev, chan, val);
+ }
+ s->readback[chan] = val;
return insn->n;
}
-static int das08_ao_rinsn(struct comedi_device *dev,
- struct comedi_subdevice *s,
- struct comedi_insn *insn, unsigned int *data)
-{
- struct das08_private_struct *devpriv = dev->private;
- unsigned int n;
- unsigned int chan;
-
- chan = CR_CHAN(insn->chanspec);
-
- for (n = 0; n < insn->n; n++)
- data[n] = devpriv->ao_readback[chan];
-
- return n;
-}
-
static void i8254_initialize(struct comedi_device *dev)
{
const struct das08_board_struct *thisboard = comedi_board(dev);
@@ -461,6 +436,7 @@ int das08_common_attach(struct comedi_device *dev, unsigned long iobase)
struct das08_private_struct *devpriv = dev->private;
struct comedi_subdevice *s;
int ret;
+ int i;
dev->iobase = iobase;
@@ -498,8 +474,17 @@ int das08_common_attach(struct comedi_device *dev, unsigned long iobase)
s->maxdata = (1 << thisboard->ao_nbits) - 1;
s->range_table = &range_bipolar5;
s->insn_write = das08_ao_insn_write;
- s->insn_read = das08_ao_rinsn;
- das08_ao_initialize(dev, s);
+ s->insn_read = comedi_readback_insn_read;
+
+ ret = comedi_alloc_subdev_readback(s);
+ if (ret)
+ return ret;
+
+ /* intialize all channels to 0V */
+ for (i = 0; i < s->n_chan; i++) {
+ s->readback[i] = s->maxdata / 2;
+ das08_ao_set_data(dev, i, s->readback[i]);
+ }
} else {
s->type = COMEDI_SUBD_UNUSED;
}
diff --git a/drivers/staging/comedi/drivers/das08.h b/drivers/staging/comedi/drivers/das08.h
index 18cc170..f86167da 100644
--- a/drivers/staging/comedi/drivers/das08.h
+++ b/drivers/staging/comedi/drivers/das08.h
@@ -44,7 +44,6 @@ struct das08_private_struct {
* without separate do register
*/
const unsigned int *pg_gainlist;
- unsigned int ao_readback[2]; /* assume 2 AO channels */
};
int das08_common_attach(struct comedi_device *dev, unsigned long iobase);
--
2.0.3
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