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staging: comedi: das800: tidy up das800_ai_insn_read()

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Introduce a couple helper functions to read the 16-bit analog input
sample and to wait for the analog conversion to complete.

Tidy up the das800_ai_insn_read() function by using the new helpers.
Also, remove the need for 'thisboard' in the function by checking the
subdevice 'maxdata' variable to determine the analog input resolution.

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 2013-04-22 18:37:03 -07:00 committed by Greg Kroah-Hartman
parent e245b6d126
commit b4780a3afb
1 changed files with 35 additions and 28 deletions
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63
drivers/staging/comedi/drivers/das800.c
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@ -473,6 +473,14 @@ static int das800_ai_do_cmd(struct comedi_device *dev,
return 0;
}
static unsigned int das800_ai_get_sample(struct comedi_device *dev)
{
unsigned int lsb = inb(dev->iobase + DAS800_LSB);
unsigned int msb = inb(dev->iobase + DAS800_MSB);
return (msb << 8) | lsb;
}
static irqreturn_t das800_interrupt(int irq, void *d)
{
short i; /* loop index */
@ -570,61 +578,60 @@ static irqreturn_t das800_interrupt(int irq, void *d)
return IRQ_HANDLED;
}
static int das800_wait_for_conv(struct comedi_device *dev, int timeout)
{
int i;
for (i = 0; i < timeout; i++) {
if (!(inb(dev->iobase + DAS800_STATUS) & BUSY))
return 0;
}
return -ETIME;
}
static int das800_ai_insn_read(struct comedi_device *dev,
struct comedi_subdevice *s,
struct comedi_insn *insn,
unsigned int *data)
{
const struct das800_board *thisboard = comedi_board(dev);
struct das800_private *devpriv = dev->private;
int i, n;
int chan;
int range;
int lsb, msb;
int timeout = 1000;
unsigned int chan = CR_CHAN(insn->chanspec);
unsigned int range = CR_RANGE(insn->chanspec);
unsigned long irq_flags;
unsigned int val;
int ret;
int i;
das800_disable(dev);
/* set multiplexer */
chan = CR_CHAN(insn->chanspec);
spin_lock_irqsave(&dev->spinlock, irq_flags);
das800_ind_write(dev, chan | devpriv->do_bits, CONTROL1);
spin_unlock_irqrestore(&dev->spinlock, irq_flags);
/* set gain / range */
range = CR_RANGE(insn->chanspec);
if (thisboard->resolution == 12 && range)
if (s->maxdata == 0x0fff && range)
range += 0x7;
range &= 0xf;
outb(range, dev->iobase + DAS800_GAIN);
udelay(5);
for (n = 0; n < insn->n; n++) {
for (i = 0; i < insn->n; i++) {
/* trigger conversion */
outb_p(0, dev->iobase + DAS800_MSB);
for (i = 0; i < timeout; i++) {
if (!(inb(dev->iobase + DAS800_STATUS) & BUSY))
break;
}
if (i == timeout) {
comedi_error(dev, "timeout");
return -ETIME;
}
lsb = inb(dev->iobase + DAS800_LSB);
msb = inb(dev->iobase + DAS800_MSB);
if (thisboard->resolution == 12) {
data[n] = (lsb >> 4) & 0xff;
data[n] |= (msb << 4);
} else {
data[n] = (msb << 8) | lsb;
}
ret = das800_wait_for_conv(dev, 1000);
if (ret)
return ret;
val = das800_ai_get_sample(dev);
if (s->maxdata == 0x0fff)
val >>= 4; /* 12-bit sample */
data[i] = val & s->maxdata;
}
return n;
return insn->n;
}
static int das800_di_insn_bits(struct comedi_device *dev,