kybaaz/linux-xiaomi-chiron
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

staging: comedi: pcl818: tidy up the analog input (*insn_read)

Browse source 
For aesthetics, move this function out of the async command support
code.

For safety, the INT request (end-of-conversion flag) should be cleared
before doing each conversion and after the final data sample is read.
This driver already clears the flag before starting a conversion but it
does not clear the flag after the final sample.

Refactor the function a bit so that the flag is cleared for a conversion
timeout and after the last sample.

Do a bit of other tidying up during the move.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
H Hartley Sweeten 2014-03-04 11:30:00 -07:00 • committed by Greg Kroah-Hartman
parent 9350557325
commit 8916f5bcdf
1 changed files with 36 additions and 37 deletions
Download patch file Download diff file Expand all files Collapse all files

73
drivers/staging/comedi/drivers/pcl818.c
View file

@ -443,43 +443,6 @@ static int pcl818_ai_eoc(struct comedi_device *dev,
return -EBUSY;
}
static int pcl818_ai_insn_read(struct comedi_device *dev,
struct comedi_subdevice *s,
struct comedi_insn *insn, unsigned int *data)
{
int ret;
int n;
/* software trigger, DMA and INT off */
outb(0, dev->iobase + PCL818_CONTROL);
/* select channel */
outb(muxonechan[CR_CHAN(insn->chanspec)], dev->iobase + PCL818_MUX);
/* select gain */
outb(CR_RANGE(insn->chanspec), dev->iobase + PCL818_RANGE);
for (n = 0; n < insn->n; n++) {
/* clear INT (conversion end) flag */
outb(0, dev->iobase + PCL818_CLRINT);
/* start conversion */
outb(0, dev->iobase + PCL818_AD_LO);
ret = comedi_timeout(dev, s, insn, pcl818_ai_eoc, 0);
if (ret) {
/* clear INT (conversion end) flag */
outb(0, dev->iobase + PCL818_CLRINT);
return ret;
}
data[n] = pcl818_ai_get_sample(dev, s, NULL);
}
return n;
}
static bool pcl818_ai_dropout(struct comedi_device *dev,
struct comedi_subdevice *s,
unsigned int chan)
@ -963,6 +926,42 @@ static int pcl818_ai_cancel(struct comedi_device *dev,
return 0;
}
static int pcl818_ai_insn_read(struct comedi_device *dev,
struct comedi_subdevice *s,
struct comedi_insn *insn,
unsigned int *data)
{
unsigned int chan = CR_CHAN(insn->chanspec);
unsigned int range = CR_RANGE(insn->chanspec);
int ret = 0;
int i;
/* software trigger, DMA and INT off */
outb(0, dev->iobase + PCL818_CONTROL);
/* select channel */
outb(muxonechan[chan], dev->iobase + PCL818_MUX);
/* select gain */
outb(range, dev->iobase + PCL818_RANGE);
for (i = 0; i < insn->n; i++) {
/* clear INT (conversion end) flag */
outb(0, dev->iobase + PCL818_CLRINT);
/* start conversion */
outb(0, dev->iobase + PCL818_AD_LO);
ret = comedi_timeout(dev, s, insn, pcl818_ai_eoc, 0);
if (ret)
break;
data[i] = pcl818_ai_get_sample(dev, s, NULL);
}
/* clear INT (conversion end) flag */
outb(0, dev->iobase + PCL818_CLRINT);
return ret ? ret : insn->n;
}
static int pcl818_ao_insn_write(struct comedi_device *dev,
struct comedi_subdevice *s,
struct comedi_insn *insn,