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staging: comedi: pcl711: no need to calc the timer values twice

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The comedi core always calls the (*do_cmdtest) function to validate
a command before it calls the (*do_cmd) function.

Since the (*do_cmdtest) has already calculated the timer values in
order to validate the cmd->scan_begin_arg there is no reason to
recalc the values in the (*do_cmd).

This also fixes a bug in the driver. The (*do_cmdtest) was using a
time base value of 100 and but the (*do_cmd) was using a time base
of 500. These result in different timer values. The functions used
to calculate the values are actually the same due to a #define in
the 8253.h header.

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 2013-09-20 16:44:08 -07:00 committed by Greg Kroah-Hartman
parent 326d875da3
commit 8fbf1f4569
1 changed files with 8 additions and 15 deletions
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23
drivers/staging/comedi/drivers/pcl711.c
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@ -331,7 +331,6 @@ static int pcl711_ai_cmdtest(struct comedi_device *dev,
err |= cfc_check_trigger_arg_is(&cmd->scan_begin_arg, 0);
} else {
#define MAX_SPEED 1000
#define TIMER_BASE 100
err |= cfc_check_trigger_arg_min(&cmd->scan_begin_arg,
MAX_SPEED);
}
@ -352,11 +351,11 @@ static int pcl711_ai_cmdtest(struct comedi_device *dev,
if (cmd->scan_begin_src == TRIG_TIMER) {
tmp = cmd->scan_begin_arg;
i8253_cascade_ns_to_timer_2div(TIMER_BASE,
&devpriv->divisor1,
&devpriv->divisor2,
&cmd->scan_begin_arg,
cmd->flags & TRIG_ROUND_MASK);
i8253_cascade_ns_to_timer(500, /* 2 Mhz */
&devpriv->divisor1,
&devpriv->divisor2,
&cmd->scan_begin_arg,
cmd->flags & TRIG_ROUND_MASK);
if (tmp != cmd->scan_begin_arg)
err++;
}
@ -369,22 +368,16 @@ static int pcl711_ai_cmdtest(struct comedi_device *dev,
static int pcl711_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
{
int timer1, timer2;
struct pcl711_private *devpriv = dev->private;
struct comedi_cmd *cmd = &s->async->cmd;
pcl711_set_changain(dev, s, cmd->chanlist[0]);
if (cmd->scan_begin_src == TRIG_TIMER) {
timer1 = timer2 = 0;
i8253_cascade_ns_to_timer(500, /* 2 Mhz */
&timer1, &timer2,
&cmd->scan_begin_arg,
TRIG_ROUND_NEAREST);
i8254_load(dev->iobase + PCL711_TIMER_BASE, 0,
1, timer1, I8254_MODE2 | I8254_BINARY);
1, devpriv->divisor1, I8254_MODE2 | I8254_BINARY);
i8254_load(dev->iobase + PCL711_TIMER_BASE, 0,
2, timer2, I8254_MODE2 | I8254_BINARY);
2, devpriv->divisor2, I8254_MODE2 | I8254_BINARY);
/* clear pending interrupts (just in case) */
outb(0, dev->iobase + PCL711_CLRINTR);