The analog input async command can use the pacer for the scan_begin_src
or 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.
For aesthetics, rename the setup_counters() function so it has namespace
associated with the driver. Refactor the function to use the values from
the private data and absorb das1800_set_frequency() to clarify the code.
Refactor the function 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.
This function will not fail so change the return type to void to simplify
the (*do_cmd) a bit.
Signed-off-by: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>
Cc: Ian Abbott <abbotti@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/staging/comedi/drivers/das1800.c | 76 +++++++-------------------------
1 file changed, 16 insertions(+), 60 deletions(-)
diff --git a/drivers/staging/comedi/drivers/das1800.c b/drivers/staging/comedi/drivers/das1800.c
index 3d5bc8e..5941b6c 100644
--- a/drivers/staging/comedi/drivers/das1800.c
+++ b/drivers/staging/comedi/drivers/das1800.c
@@ -962,68 +962,29 @@ static int control_c_bits(const struct comedi_cmd *cmd)
return control_c;
}
-/* loads counters with divisor1, divisor2 from private structure */
-static int das1800_set_frequency(struct comedi_device *dev)
+static void das1800_setup_counters(struct comedi_device *dev,
+ const struct comedi_cmd *cmd)
{
struct das1800_private *devpriv = dev->private;
- int err = 0;
-
- /* counter 1, mode 2 */
- if (i8254_load(dev->iobase + DAS1800_COUNTER, 0, 1, devpriv->divisor1,
- 2))
- err++;
- /* counter 2, mode 2 */
- if (i8254_load(dev->iobase + DAS1800_COUNTER, 0, 2, devpriv->divisor2,
- 2))
- err++;
- if (err)
- return -1;
+ unsigned long timer_base = dev->iobase + DAS1800_COUNTER;
- return 0;
-}
-
-/* sets up counters */
-static int setup_counters(struct comedi_device *dev,
- const struct comedi_cmd *cmd)
-{
- struct das1800_private *devpriv = dev->private;
- unsigned int period;
+ /* setup cascaded counters for conversion/scan frequency */
+ if ((cmd->scan_begin_src == TRIG_FOLLOW ||
+ cmd->scan_begin_src == TRIG_TIMER) &&
+ cmd->convert_src == TRIG_TIMER) {
+ i8254_set_mode(timer_base, 0, 1, I8254_MODE2 | I8254_BINARY);
+ i8254_set_mode(timer_base, 0, 2, I8254_MODE2 | I8254_BINARY);
- /* setup cascaded counters for conversion/scan frequency */
- switch (cmd->scan_begin_src) {
- case TRIG_FOLLOW: /* not in burst mode */
- if (cmd->convert_src == TRIG_TIMER) {
- /* set conversion frequency */
- period = cmd->convert_arg;
- i8253_cascade_ns_to_timer(I8254_OSC_BASE_5MHZ,
- &devpriv->divisor1,
- &devpriv->divisor2,
- &period, cmd->flags);
- if (das1800_set_frequency(dev) < 0)
- return -1;
- }
- break;
- case TRIG_TIMER: /* in burst mode */
- /* set scan frequency */
- period = cmd->scan_begin_arg;
- i8253_cascade_ns_to_timer(I8254_OSC_BASE_5MHZ,
- &devpriv->divisor1,
- &devpriv->divisor2,
- &period, cmd->flags);
- if (das1800_set_frequency(dev) < 0)
- return -1;
- break;
- default:
- break;
+ i8254_write(timer_base, 0, 1, devpriv->divisor1);
+ i8254_write(timer_base, 0, 2, devpriv->divisor2);
}
- /* setup counter 0 for 'about triggering' */
+ /* setup counter 0 for 'about triggering' */
if (cmd->stop_src == TRIG_EXT) {
- /* load counter 0 in mode 0 */
- i8254_load(dev->iobase + DAS1800_COUNTER, 0, 0, 1, 0);
- }
+ i8254_set_mode(timer_base, 0, 0, I8254_MODE0 | I8254_BINARY);
- return 0;
+ i8254_write(timer_base, 0, 0, 1);
+ }
}
/* utility function that suggests a dma transfer size based on the conversion period 'ns' */
@@ -1136,7 +1097,6 @@ static int das1800_ai_do_cmd(struct comedi_device *dev,
struct comedi_subdevice *s)
{
struct das1800_private *devpriv = dev->private;
- int ret;
int control_a, control_c;
struct comedi_async *async = s->async;
const struct comedi_cmd *cmd = &async->cmd;
@@ -1167,11 +1127,7 @@ static int das1800_ai_do_cmd(struct comedi_device *dev,
/* setup card and start */
program_chanlist(dev, cmd);
- ret = setup_counters(dev, cmd);
- if (ret < 0) {
- comedi_error(dev, "Error setting up counters");
- return ret;
- }
+ das1800_setup_counters(dev, cmd);
setup_dma(dev, cmd);
outb(control_c, dev->iobase + DAS1800_CONTROL_C);
/* set conversion rate and length for burst mode */
--
1.9.2
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