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staging: comedi: das16m1: don't calc pacer divisors twice

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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.

Refactor das16m1_set_pacer() to use the i8254_set_mode() and i8254_write()
helpers instead of i8254_load(). This allows us to use the I8254_* defines
when setting the mode to clarify the code.

Tidy up das16m1_cmd_exec() a bit. The pacer only needs to be set when the
convert_src is TRIG_TIMER.

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 2014-04-29 12:59:30 -07:00 • committed by Greg Kroah-Hartman
parent 33eafb7761
commit 863e07c9f8
1 changed files with 14 additions and 27 deletions
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41
drivers/staging/comedi/drivers/das16m1.c
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@ -254,26 +254,16 @@ static int das16m1_cmd_test(struct comedi_device *dev,
return 0; return 0;
} }
/* This function takes a time in nanoseconds and sets the * static void das16m1_set_pacer(struct comedi_device *dev)
* 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)
{ {
struct das16m1_private_struct *devpriv = dev->private; 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, i8254_set_mode(timer_base, 0, 1, I8254_MODE2 | I8254_BINARY);
&devpriv->divisor1, i8254_set_mode(timer_base, 0, 2, I8254_MODE2 | I8254_BINARY);
&devpriv->divisor2,
&ns, rounding_flags);
/* Write the values of ctr1 and ctr2 into counters 1 and 2 */ i8254_write(timer_base, 0, 1, devpriv->divisor1);
i8254_load(dev->iobase + DAS16M1_8254_SECOND, 0, 1, devpriv->divisor1, i8254_write(timer_base, 0, 2, devpriv->divisor2);
2);
i8254_load(dev->iobase + DAS16M1_8254_SECOND, 0, 2, devpriv->divisor2,
2);
return ns;
} }
static int das16m1_cmd_exec(struct comedi_device *dev, static int das16m1_cmd_exec(struct comedi_device *dev,
@ -307,10 +297,14 @@ static int das16m1_cmd_exec(struct comedi_device *dev,
outb(byte, dev->iobase + DAS16M1_QUEUE_DATA); outb(byte, dev->iobase + DAS16M1_QUEUE_DATA);
} }
/* set counter mode and counts */ /* enable interrupts and set internal pacer counter mode and counts */
cmd->convert_arg = devpriv->control_state &= ~PACER_MASK;
das16m1_set_pacer(dev, cmd->convert_arg, if (cmd->convert_src == TRIG_TIMER) {
cmd->flags & TRIG_ROUND_MASK); das16m1_set_pacer(dev);
devpriv->control_state |= INT_PACER;
} else { /* TRIG_EXT */
devpriv->control_state |= EXT_PACER;
}
/* set control & status register */ /* set control & status register */
byte = 0; byte = 0;
@ -323,13 +317,6 @@ static int das16m1_cmd_exec(struct comedi_device *dev,
/* clear interrupt bit */ /* clear interrupt bit */
outb(0, dev->iobase + DAS16M1_CLEAR_INTR); 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; devpriv->control_state |= INTE;
outb(devpriv->control_state, dev->iobase + DAS16M1_INTR_CONTROL); outb(devpriv->control_state, dev->iobase + DAS16M1_INTR_CONTROL);