/*
    lib/command.c
    comedi library routines

    COMEDILIB - Control and Measurement Device Interface Library
    Copyright (C) 2000 David A. Schleef <ds@stm.lbl.gov>

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

*/

#include <stdio.h>
#include <math.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <errno.h>
#include <comedi.h>
#include <string.h>

#include <libinternal.h>



int comedi_data_write(comedi_t *it,unsigned int subdev,unsigned int chan,unsigned int range,
		unsigned int aref,lsampl_t data)
{
	comedi_trig cmd={
		mode:		0,
		flags:		TRIG_WRITE,
		n_chan:		1,
		n:		1,
		trigsrc:	0,
		trigvar:	0,
		trigvar1:	0,
	};
	sampl_t sdata=data;

	if(!valid_chan(it,subdev,chan))
		return -1;
	
	chan=CR_PACK(chan,range,aref);

	cmd.subdev=subdev;
	if(it->subdevices[subdev].subd_flags & SDF_LSAMPL){
		cmd.data=(sampl_t *)(&data);
	}else{
		cmd.data=&sdata;
	}
	cmd.chanlist=&chan;

	return ioctl_trigger(it->fd,&cmd);
}


int comedi_data_read(comedi_t *it,unsigned int subdev,unsigned int chan,unsigned int range,
		unsigned int aref,lsampl_t *data)
{
	comedi_trig cmd={
		mode:		0,
		flags:		0,
		n_chan:		1,
		n:		1,
		trigsrc:	0,
		trigvar:	0,
		trigvar1:	0,
	};
	int ret;
	sampl_t sdata;

	if(!valid_chan(it,subdev,chan))
		return -1;
	
	chan=CR_PACK(chan,range,aref);
	
	cmd.subdev=subdev;
	cmd.chanlist=&chan;
	if(it->subdevices[subdev].subd_flags & SDF_LSAMPL){
		cmd.data=(sampl_t *)data;
	}else{
		cmd.data=&sdata;
	}

	ret=ioctl_trigger(it->fd,&cmd);
	if(ret<0)
		return ret;

	if(!(it->subdevices[subdev].subd_flags & SDF_LSAMPL)){
		*data=sdata;
	}

	return 0;
}

#if 1
/*
   I don't like this function, which is why it is marked out.
   The problem is the sampl_t/lsampl_t fiasco, which is beginning
   to be a PITA.
 */
int comedi_data_read_n(comedi_t *it,unsigned int subdev,unsigned int chan,unsigned int range,
		unsigned int aref,unsigned int n,lsampl_t *data)
{
	comedi_trig cmd;
	unsigned int i;
	int ret;

	if(!valid_chan(it,subdev,chan))
		return -1;
	
	if(n==0)
		return 0;

	chan=CR_PACK(chan,range,aref);
	
	memset(&cmd,0,sizeof(cmd));
	cmd.mode=0;
	cmd.n_chan=1;
	cmd.subdev=subdev;
	cmd.chanlist=&chan;

	i=0;
	while(i<n){
		cmd.data=(void *)(data+i);
		cmd.n=n-i;

		ret=ioctl_trigger(it->fd,&cmd);
		if(ret<0)
			goto out;

		i+=ret;
	}
out:
	if(i==0)return -1;

	return (int)i;
}
#endif