[PATCH 03/23] staging: comedi: das16m1: don't calc pacer divisors twice
H Hartley Sweeten
hsweeten at visionengravers.com
Mon Apr 28 18:53:37 UTC 2014
The analog input async command can use the pacer for the convert_src. The
(*do_cmdtest) calculates the divisors when validating the cmd argument.
There is no reason to recalc the divisors in the (*do_cmd). Just use the
values from the private data.
Also, tidy up das16m1_set_pacer() and das16m1_cmd_exec() 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>
---
drivers/staging/comedi/drivers/das16m1.c | 42 +++++++++++---------------------
1 file changed, 14 insertions(+), 28 deletions(-)
diff --git a/drivers/staging/comedi/drivers/das16m1.c b/drivers/staging/comedi/drivers/das16m1.c
index a9cd210..2b51a00 100644
--- a/drivers/staging/comedi/drivers/das16m1.c
+++ b/drivers/staging/comedi/drivers/das16m1.c
@@ -254,26 +254,15 @@ static int das16m1_cmd_test(struct comedi_device *dev,
return 0;
}
-/* This function takes a time in nanoseconds and sets the *
- * 2 pacer clocks to the closest frequency possible. It also *
- * returns the actual sampling period. */
-static unsigned int das16m1_set_pacer(struct comedi_device *dev,
- unsigned int ns, int rounding_flags)
+static void das16m1_set_pacer(struct comedi_device *dev)
{
struct das16m1_private_struct *devpriv = dev->private;
+ unsigned long timer_base = dev->iobase + DAS16M1_8254_SECOND;
- i8253_cascade_ns_to_timer_2div(I8254_OSC_BASE_10MHZ,
- &devpriv->divisor1,
- &devpriv->divisor2,
- &ns, rounding_flags);
-
- /* Write the values of ctr1 and ctr2 into counters 1 and 2 */
- i8254_load(dev->iobase + DAS16M1_8254_SECOND, 0, 1, devpriv->divisor1,
- 2);
- i8254_load(dev->iobase + DAS16M1_8254_SECOND, 0, 2, devpriv->divisor2,
- 2);
-
- return ns;
+ i8254_load(timer_base, 0,
+ 1, devpriv->divisor1, I8254_MODE2 | I8254_BINARY);
+ i8254_load(timer_base, 0,
+ 2, devpriv->divisor2, I8254_MODE2 | I8254_BINARY);
}
static int das16m1_cmd_exec(struct comedi_device *dev,
@@ -307,10 +296,14 @@ static int das16m1_cmd_exec(struct comedi_device *dev,
outb(byte, dev->iobase + DAS16M1_QUEUE_DATA);
}
- /* set counter mode and counts */
- cmd->convert_arg =
- das16m1_set_pacer(dev, cmd->convert_arg,
- cmd->flags & TRIG_ROUND_MASK);
+ /* enable interrupts and set internal pacer counter mode and counts */
+ devpriv->control_state &= ~PACER_MASK;
+ if (cmd->convert_src == TRIG_TIMER) {
+ das16m1_set_pacer(dev);
+ devpriv->control_state |= INT_PACER;
+ } else { /* TRIG_EXT */
+ devpriv->control_state |= EXT_PACER;
+ }
/* set control & status register */
byte = 0;
@@ -323,13 +316,6 @@ static int das16m1_cmd_exec(struct comedi_device *dev,
/* clear interrupt bit */
outb(0, dev->iobase + DAS16M1_CLEAR_INTR);
- /* enable interrupts and internal pacer */
- devpriv->control_state &= ~PACER_MASK;
- if (cmd->convert_src == TRIG_TIMER)
- devpriv->control_state |= INT_PACER;
- else
- devpriv->control_state |= EXT_PACER;
-
devpriv->control_state |= INTE;
outb(devpriv->control_state, dev->iobase + DAS16M1_INTR_CONTROL);
--
1.9.2
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