[PATCH 20/38] staging: comedi: das16: tidy up das16_ai_insn_read()
H Hartley Sweeten
hsweeten at visionengravers.com
Mon Jul 29 21:02:22 UTC 2013
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 at visionengravers.com>
Cc: Ian Abbott <abbotti at mev.co.uk>
Cc: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
---
This also fixes a bug introduced by PATCH 05/38. The 'val' should be >> 4
not the 'data[n]'. If necessary I will rebase this series to fix the patch.
drivers/staging/comedi/drivers/das16.c | 50 ++++++++++++++++++----------------
1 file changed, 27 insertions(+), 23 deletions(-)
diff --git a/drivers/staging/comedi/drivers/das16.c b/drivers/staging/comedi/drivers/das16.c
index f6d0f7e..a482bd5 100644
--- a/drivers/staging/comedi/drivers/das16.c
+++ b/drivers/staging/comedi/drivers/das16.c
@@ -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,
--
1.8.3.2
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