Commit 62319bce authored by H Hartley Sweeten's avatar H Hartley Sweeten Committed by Greg Kroah-Hartman
Browse files

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



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: default avatarH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: default avatarIan Abbott <abbotti@mev.co.uk>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 0d77ef8b

drivers/staging/comedi/drivers/quatech_daqp_cs.c

+18 −27
Original line number Diff line number Diff line
@@ -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++) {