static int rtd_ai_cmdtest()

in drivers/rtd520.c [687:826]

• 109 lines of code
• 21 McCabe index (conditional complexity)

static int rtd_ai_cmdtest(struct comedi_device *dev,
			  struct comedi_subdevice *s, struct comedi_cmd *cmd)
{
	int err = 0;
	unsigned int arg;

	/* Step 1 : check if triggers are trivially valid */

	err |= comedi_check_trigger_src(&cmd->start_src, TRIG_NOW);
	err |= comedi_check_trigger_src(&cmd->scan_begin_src,
					TRIG_TIMER | TRIG_EXT);
	err |= comedi_check_trigger_src(&cmd->convert_src,
					TRIG_TIMER | TRIG_EXT);
	err |= comedi_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
	err |= comedi_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);

	if (err)
		return 1;

	/* Step 2a : make sure trigger sources are unique */

	err |= comedi_check_trigger_is_unique(cmd->scan_begin_src);
	err |= comedi_check_trigger_is_unique(cmd->convert_src);
	err |= comedi_check_trigger_is_unique(cmd->stop_src);

	/* Step 2b : and mutually compatible */

	if (err)
		return 2;

	/* Step 3: check if arguments are trivially valid */

	err |= comedi_check_trigger_arg_is(&cmd->start_arg, 0);

	if (cmd->scan_begin_src == TRIG_TIMER) {
		/* Note: these are time periods, not actual rates */
		if (cmd->chanlist_len == 1) {	/* no scanning */
			if (comedi_check_trigger_arg_min(&cmd->scan_begin_arg,
							 RTD_MAX_SPEED_1)) {
				rtd_ns_to_timer(&cmd->scan_begin_arg,
						CMDF_ROUND_UP);
				err |= -EINVAL;
			}
			if (comedi_check_trigger_arg_max(&cmd->scan_begin_arg,
							 RTD_MIN_SPEED_1)) {
				rtd_ns_to_timer(&cmd->scan_begin_arg,
						CMDF_ROUND_DOWN);
				err |= -EINVAL;
			}
		} else {
			if (comedi_check_trigger_arg_min(&cmd->scan_begin_arg,
							 RTD_MAX_SPEED)) {
				rtd_ns_to_timer(&cmd->scan_begin_arg,
						CMDF_ROUND_UP);
				err |= -EINVAL;
			}
			if (comedi_check_trigger_arg_max(&cmd->scan_begin_arg,
							 RTD_MIN_SPEED)) {
				rtd_ns_to_timer(&cmd->scan_begin_arg,
						CMDF_ROUND_DOWN);
				err |= -EINVAL;
			}
		}
	} else {
		/* external trigger */
		/* should be level/edge, hi/lo specification here */
		/* should specify multiple external triggers */
		err |= comedi_check_trigger_arg_max(&cmd->scan_begin_arg, 9);
	}

	if (cmd->convert_src == TRIG_TIMER) {
		if (cmd->chanlist_len == 1) {	/* no scanning */
			if (comedi_check_trigger_arg_min(&cmd->convert_arg,
							 RTD_MAX_SPEED_1)) {
				rtd_ns_to_timer(&cmd->convert_arg,
						CMDF_ROUND_UP);
				err |= -EINVAL;
			}
			if (comedi_check_trigger_arg_max(&cmd->convert_arg,
							 RTD_MIN_SPEED_1)) {
				rtd_ns_to_timer(&cmd->convert_arg,
						CMDF_ROUND_DOWN);
				err |= -EINVAL;
			}
		} else {
			if (comedi_check_trigger_arg_min(&cmd->convert_arg,
							 RTD_MAX_SPEED)) {
				rtd_ns_to_timer(&cmd->convert_arg,
						CMDF_ROUND_UP);
				err |= -EINVAL;
			}
			if (comedi_check_trigger_arg_max(&cmd->convert_arg,
							 RTD_MIN_SPEED)) {
				rtd_ns_to_timer(&cmd->convert_arg,
						CMDF_ROUND_DOWN);
				err |= -EINVAL;
			}
		}
	} else {
		/* external trigger */
		/* see above */
		err |= comedi_check_trigger_arg_max(&cmd->convert_arg, 9);
	}

	err |= comedi_check_trigger_arg_is(&cmd->scan_end_arg,
					   cmd->chanlist_len);

	if (cmd->stop_src == TRIG_COUNT)
		err |= comedi_check_trigger_arg_min(&cmd->stop_arg, 1);
	else	/* TRIG_NONE */
		err |= comedi_check_trigger_arg_is(&cmd->stop_arg, 0);

	if (err)
		return 3;

	/* step 4: fix up any arguments */

	if (cmd->scan_begin_src == TRIG_TIMER) {
		arg = cmd->scan_begin_arg;
		rtd_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;
		rtd_ns_to_timer(&arg, cmd->flags);
		err |= comedi_check_trigger_arg_is(&cmd->convert_arg, arg);

		if (cmd->scan_begin_src == TRIG_TIMER) {
			arg = cmd->convert_arg * cmd->scan_end_arg;
			err |= comedi_check_trigger_arg_min(
					&cmd->scan_begin_arg, arg);
		}
	}

	if (err)
		return 4;

	return 0;
}