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staging: comedi: adl_pci9118: clarify acquisition mode (ai_do) determination

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The async command can operation in 4 modes in this driver.

Modes 1 and 4 use timers 1 and 2 as a cascaded timer to trigger each conversion.
Mode 1 begins the acquisitions immediately (scan_begin_src == TRIG_FOLLOW) and
Mode 4 begins after an external trigger (scan_begin_src == TRIG_EXT). Both modes
use a convert_src == TRIG_TIMER.

Mode 2 uses timers 1 and 2 in a double timed action (scan_begin_src == TRIG_TIMER
and convert_src != TRIG_EXT (TRIG_TIMER and TRIG_NOW are valid)).

Mode 3 does not use the timers. Each acquisition is triggered by an external
signal (scan_begin_src == TRIG_FOLLOW and convert_src == TRIG_EXT.

The (*do_cmdtest) validates the scan_begin_src as TRIG_FOLLOW, TRIG_TIMER,
or TRIG_EXT. Remove the invalid check for TRIG_INT in the (*do_cmd).

Clarify the logic used to determine the mode in the (*do_cmd).

Also, simplify pci9118_calc_divisors(). Call i8253_cascade_ns_to_timer() directly
in the (*do_cmd) for the mode 1 and mode 4 cases. Call pci9118_calc_divisors()
only for mode 2 acquisitions.

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 2014-09-09 13:05:49 -07:00 • committed by Greg Kroah-Hartman
parent abaaa7f83a
commit f3d3dad659
1 changed files with 30 additions and 47 deletions
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77
drivers/staging/comedi/drivers/adl_pci9118.c
View file

@ -513,7 +513,7 @@ static void pci9118_exttrg_enable(struct comedi_device *dev, bool enable)
pci9118_amcc_int_ena(dev, false);
}
static void pci9118_calc_divisors(char mode, struct comedi_device *dev,
static void pci9118_calc_divisors(struct comedi_device *dev,
struct comedi_subdevice *s,
unsigned int *tim1, unsigned int *tim2,
unsigned int flags, int chans,
@ -522,32 +522,21 @@ static void pci9118_calc_divisors(char mode, struct comedi_device *dev,
{
struct comedi_cmd *cmd = &s->async->cmd;
switch (mode) {
case 1:
case 4:
i8253_cascade_ns_to_timer(I8254_OSC_BASE_4MHZ,
div1, div2,
tim2, flags & CMDF_ROUND_NEAREST);
break;
case 2:
*div1 = *tim2 / I8254_OSC_BASE_4MHZ;
/* convert timer (burst) */
*div2 = *tim1 / I8254_OSC_BASE_4MHZ; /* scan timer */
*div2 = *div2 / *div1; /* major timer is c1*c2 */
if (*div2 < chans)
*div2 = chans;
*div1 = *tim2 / I8254_OSC_BASE_4MHZ; /* convert timer (burst) */
*div2 = *tim1 / I8254_OSC_BASE_4MHZ; /* scan timer */
*div2 = *div2 / *div1; /* major timer is c1*c2 */
if (*div2 < chans)
*div2 = chans;
*tim2 = *div1 * I8254_OSC_BASE_4MHZ; /* real convert timer */
*tim2 = *div1 * I8254_OSC_BASE_4MHZ; /* real convert timer */
if (cmd->convert_src == TRIG_NOW && !chnsshfront) {
/* use BSSH signal */
if (*div2 < (chans + 2))
*div2 = chans + 2;
}
*tim1 = *div1 * *div2 * I8254_OSC_BASE_4MHZ;
break;
if (cmd->convert_src == TRIG_NOW && !chnsshfront) {
/* use BSSH signal */
if (*div2 < (chans + 2))
*div2 = chans + 2;
}
*tim1 = *div1 * *div2 * I8254_OSC_BASE_4MHZ;
}
static void pci9118_start_pacer(struct comedi_device *dev, int mode)
@ -1322,40 +1311,33 @@ static int pci9118_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
pci9118_set_chanlist(dev, s, cmd->chanlist_len, cmd->chanlist,
devpriv->ai_add_front, devpriv->ai_add_back);
/* compute timers settings */
/*
* simplest way, fr=4Mhz/(tim1*tim2),
* channel manipulation without timers effect
*/
if (((cmd->scan_begin_src == TRIG_FOLLOW) ||
(cmd->scan_begin_src == TRIG_EXT)) &&
(cmd->convert_src == TRIG_TIMER)) {
/* both timer is used for one time */
/* Determine acqusition mode and calculate timing */
if (cmd->scan_begin_src != TRIG_TIMER &&
cmd->convert_src == TRIG_TIMER) {
/* cascaded timers 1 and 2 are used for convert timing */
if (cmd->scan_begin_src == TRIG_EXT)
devpriv->ai_do = 4;
else
devpriv->ai_do = 1;
pci9118_calc_divisors(devpriv->ai_do, dev, s,
&cmd->scan_begin_arg, &cmd->convert_arg,
devpriv->ai_flags,
devpriv->ai_n_realscanlen,
&devpriv->ai_divisor1,
&devpriv->ai_divisor2,
devpriv->ai_add_front);
i8253_cascade_ns_to_timer(I8254_OSC_BASE_4MHZ,
&devpriv->ai_divisor1,
&devpriv->ai_divisor2,
&cmd->convert_arg,
devpriv->ai_flags &
CMDF_ROUND_NEAREST);
}
if ((cmd->scan_begin_src == TRIG_TIMER) &&
((cmd->convert_src == TRIG_TIMER) ||
(cmd->convert_src == TRIG_NOW))) {
/* double timed action */
if (cmd->scan_begin_src == TRIG_TIMER &&
cmd->convert_src != TRIG_EXT) {
if (!devpriv->usedma) {
dev_err(dev->class_dev,
"cmd->scan_begin_src=TRIG_TIMER works only with bus mastering!\n");
return -EIO;
}
/* double timed action */
devpriv->ai_do = 2;
pci9118_calc_divisors(devpriv->ai_do, dev, s,
pci9118_calc_divisors(dev, s,
&cmd->scan_begin_arg, &cmd->convert_arg,
devpriv->ai_flags,
devpriv->ai_n_realscanlen,
@ -1364,8 +1346,9 @@ static int pci9118_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
devpriv->ai_add_front);
}
if ((cmd->scan_begin_src == TRIG_FOLLOW)
&& (cmd->convert_src == TRIG_EXT)) {
if (cmd->scan_begin_src == TRIG_FOLLOW &&
cmd->convert_src == TRIG_EXT) {
/* external trigger conversion */
devpriv->ai_do = 3;
}