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staging: comedi: das16: tidy up das16_ai_insn_read() 

Factor out the loop that waits for the ai conversion to complete.

Tidy up the function a bit.

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 2013-07-29 14:02:22 -07:00 committed by Greg Kroah-Hartman
parent b53ceaf71a
commit 73ef2b5387
1 changed files with 27 additions and 23 deletions
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50
drivers/staging/comedi/drivers/das16.c
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@ -253,8 +253,6 @@ struct das16_board {
unsigned int id;
};
#define DAS16_TIMEOUT 1000
/* Period for timer interrupt in jiffies. It's a function
* to deal with possibility of dynamic HZ patches */
static inline int timer_period(void)
@ -564,55 +562,61 @@ static void das16_reset(struct comedi_device *dev)
outb(0, dev->iobase + DAS16_CNTR_CONTROL);
}
static int das16_ai_wait_for_conv(struct comedi_device *dev,
unsigned int timeout)
{
unsigned int status;
int i;
for (i = 0; i < timeout; i++) {
status = inb(dev->iobase + DAS16_STATUS);
if (!(status & BUSY))
return 0;
}
return -ETIME;
}
static int das16_ai_insn_read(struct comedi_device *dev,
struct comedi_subdevice *s,
struct comedi_insn *insn,
unsigned int *data)
{
const struct das16_board *board = comedi_board(dev);
int i, n;
int range;
int chan;
unsigned int chan = CR_CHAN(insn->chanspec);
unsigned int range = CR_RANGE(insn->chanspec);
unsigned int val;
int ret;
int i;
das16_ai_disable(dev);
/* set multiplexer */
chan = CR_CHAN(insn->chanspec);
chan |= CR_CHAN(insn->chanspec) << 4;
outb(chan, dev->iobase + DAS16_MUX);
outb(chan | (chan << 4), dev->iobase + DAS16_MUX);
/* set gain */
if (board->ai_pg != das16_pg_none) {
range = CR_RANGE(insn->chanspec);
outb((das16_gainlists[board->ai_pg])[range],
dev->iobase + DAS16_GAIN);
}
for (n = 0; n < insn->n; n++) {
unsigned int val;
for (i = 0; i < insn->n; i++) {
/* trigger conversion */
outb_p(0, dev->iobase + DAS16_TRIG);
for (i = 0; i < DAS16_TIMEOUT; i++) {
if (!(inb(dev->iobase + DAS16_STATUS) & BUSY))
break;
}
if (i == DAS16_TIMEOUT) {
printk("das16: timeout\n");
return -ETIME;
}
ret = das16_ai_wait_for_conv(dev, 1000);
if (ret)
return ret;
val = inb(dev->iobase + DAS16_AI_MSB) << 8;
val |= inb(dev->iobase + DAS16_AI_LSB);
if (s->maxdata == 0x0fff)
data[n] >>= 4;
val >>= 4;
val &= s->maxdata;
data[n] = val;
data[i] = val;
}
return n;
return insn->n;
}
static int das16_di_insn_bits(struct comedi_device *dev,