drivers/staging/comedi/drivers/pcm_common.c

#include "../comedidev.h"
#include "pcm_common.h"

/*
 * 'do_cmdtest' function for an 'INTERRUPT' subdevice.  This is for
 * the PCM drivers.
 */
int comedi_pcm_cmdtest(struct comedi_device *dev,
		       struct comedi_subdevice *s, struct comedi_cmd *cmd)
{
	int err = 0;
	unsigned int tmp;

	/* step 1: make sure trigger sources are trivially valid */

	tmp = cmd->start_src;
	cmd->start_src &= (TRIG_NOW | TRIG_INT);
	if (!cmd->start_src || tmp != cmd->start_src)
		err++;

	tmp = cmd->scan_begin_src;
	cmd->scan_begin_src &= TRIG_EXT;
	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
		err++;

	tmp = cmd->convert_src;
	cmd->convert_src &= TRIG_NOW;
	if (!cmd->convert_src || tmp != cmd->convert_src)
		err++;

	tmp = cmd->scan_end_src;
	cmd->scan_end_src &= TRIG_COUNT;
	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
		err++;

	tmp = cmd->stop_src;
	cmd->stop_src &= (TRIG_COUNT | TRIG_NONE);
	if (!cmd->stop_src || tmp != cmd->stop_src)
		err++;

	if (err)
		return 1;

	/* step 2: make sure trigger sources are unique and
	 * mutually compatible */

	/* these tests are true if more than one _src bit is set */
	if ((cmd->start_src & (cmd->start_src - 1)) != 0)
		err++;
	if ((cmd->scan_begin_src & (cmd->scan_begin_src - 1)) != 0)
		err++;
	if ((cmd->convert_src & (cmd->convert_src - 1)) != 0)
		err++;
	if ((cmd->scan_end_src & (cmd->scan_end_src - 1)) != 0)
		err++;
	if ((cmd->stop_src & (cmd->stop_src - 1)) != 0)
		err++;

	if (err)
		return 2;

	/* step 3: make sure arguments are trivially compatible */

	/* cmd->start_src == TRIG_NOW || cmd->start_src == TRIG_INT */
	if (cmd->start_arg != 0) {
		cmd->start_arg = 0;
		err++;
	}

	/* cmd->scan_begin_src == TRIG_EXT */
	if (cmd->scan_begin_arg != 0) {
		cmd->scan_begin_arg = 0;
		err++;
	}

	/* cmd->convert_src == TRIG_NOW */
	if (cmd->convert_arg != 0) {
		cmd->convert_arg = 0;
		err++;
	}

	/* cmd->scan_end_src == TRIG_COUNT */
	if (cmd->scan_end_arg != cmd->chanlist_len) {
		cmd->scan_end_arg = cmd->chanlist_len;
		err++;
	}

	switch (cmd->stop_src) {
	case TRIG_COUNT:
		/* any count allowed */
		break;
	case TRIG_NONE:
		if (cmd->stop_arg != 0) {
			cmd->stop_arg = 0;
			err++;
		}
		break;
	default:
		break;
	}

	if (err)
		return 3;

	/* step 4: fix up any arguments */

	/* if (err) return 4; */

	return 0;
}
EXPORT_SYMBOL(comedi_pcm_cmdtest);