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staging: comedi: quatech_daqp_cs: avoid calculating pacer divisor multiple times

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The pacer will either be used to trigger each conversion or to start each
scan. Modify the (*do_cmdtest) so that one one divisor calculation is needed.
Save the divisor value in the private data so that the (*do_cmd) does not
have to do the calculation again.

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
2015-10-05 14:23:11 -07:00
committed by Greg Kroah-Hartman
parent 0d77ef8b43
commit 62319bceef
1 changed files with 18 additions and 27 deletions
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45
drivers/staging/comedi/drivers/quatech_daqp_cs.c
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@@ -144,6 +144,7 @@
#define DAQP_MAX_TIMER_SPEED 10000 /* 100 kHz in nanoseconds */
struct daqp_private {
unsigned int pacer_div;
int stop;
};
@@ -359,17 +360,18 @@ static int daqp_ns_to_timer(unsigned int *ns, unsigned int flags)
return timer;
}
/* cmdtest tests a particular command to see if it is valid.
* Using the cmdtest ioctl, a user can create a valid cmd
* and then have it executed by the cmd ioctl.
*
* cmdtest returns 1,2,3,4 or 0, depending on which tests
* the command passes.
*/
static void daqp_set_pacer(struct comedi_device *dev, unsigned int val)
{
outb(val & 0xff, dev->iobase + DAQP_PACER_LOW_REG);
outb((val >> 8) & 0xff, dev->iobase + DAQP_PACER_MID_REG);
outb((val >> 16) & 0xff, dev->iobase + DAQP_PACER_HIGH_REG);
}
static int daqp_ai_cmdtest(struct comedi_device *dev,
struct comedi_subdevice *s, struct comedi_cmd *cmd)
struct comedi_subdevice *s,
struct comedi_cmd *cmd)
{
struct daqp_private *devpriv = dev->private;
int err = 0;
unsigned int arg;
@@ -440,16 +442,14 @@ static int daqp_ai_cmdtest(struct comedi_device *dev,
/* step 4: fix up any arguments */
if (cmd->scan_begin_src == TRIG_TIMER) {
arg = cmd->scan_begin_arg;
daqp_ns_to_timer(&arg, cmd->flags);
err |= comedi_check_trigger_arg_is(&cmd->scan_begin_arg, arg);
}
if (cmd->convert_src == TRIG_TIMER) {
arg = cmd->convert_arg;
daqp_ns_to_timer(&arg, cmd->flags);
devpriv->pacer_div = daqp_ns_to_timer(&arg, cmd->flags);
err |= comedi_check_trigger_arg_is(&cmd->convert_arg, arg);
} else if (cmd->scan_begin_src == TRIG_TIMER) {
arg = cmd->scan_begin_arg;
devpriv->pacer_div = daqp_ns_to_timer(&arg, cmd->flags);
err |= comedi_check_trigger_arg_is(&cmd->scan_begin_arg, arg);
}
if (err)
@@ -462,7 +462,6 @@ static int daqp_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
{
struct daqp_private *devpriv = dev->private;
struct comedi_cmd *cmd = &s->async->cmd;
int counter;
int scanlist_start_on_every_entry;
int threshold;
int ret;
@@ -488,20 +487,12 @@ static int daqp_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
* each scan, so we program the pacer clock to this frequency
* and only set the SCANLIST_START bit on the first entry.
*/
daqp_set_pacer(dev, devpriv->pacer_div);
if (cmd->convert_src == TRIG_TIMER) {
counter = daqp_ns_to_timer(&cmd->convert_arg, cmd->flags);
outb(counter & 0xff, dev->iobase + DAQP_PACER_LOW_REG);
outb((counter >> 8) & 0xff, dev->iobase + DAQP_PACER_MID_REG);
outb((counter >> 16) & 0xff, dev->iobase + DAQP_PACER_HIGH_REG);
if (cmd->convert_src == TRIG_TIMER)
scanlist_start_on_every_entry = 1;
} else {
counter = daqp_ns_to_timer(&cmd->scan_begin_arg, cmd->flags);
outb(counter & 0xff, dev->iobase + DAQP_PACER_LOW_REG);
outb((counter >> 8) & 0xff, dev->iobase + DAQP_PACER_MID_REG);
outb((counter >> 16) & 0xff, dev->iobase + DAQP_PACER_HIGH_REG);
else
scanlist_start_on_every_entry = 0;
}
/* Program scan list */
for (i = 0; i < cmd->chanlist_len; i++) {