/*
    module/range.c
    comedi routines for voltage ranges

    COMEDI - Linux Control and Measurement Device Interface
    Copyright (C) 1997-8 David A. Schleef <ds@schleef.org>

    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 <linux/comedidev.h>
#include <asm/uaccess.h>


comedi_lrange range_bipolar10={ 1, {BIP_RANGE(10)}};
comedi_lrange range_bipolar5={ 1, {BIP_RANGE(5)}};
comedi_lrange range_bipolar2_5={ 1, {BIP_RANGE(2.5)}};
comedi_lrange range_unipolar10={ 1, {UNI_RANGE(10)}};
comedi_lrange range_unipolar5={ 1, {UNI_RANGE(5)}};
comedi_lrange range_unknown={ 1, {{0,1000000,UNIT_none}}};

/*
   	COMEDI_RANGEINFO
	range information ioctl

	arg:
		pointer to rangeinfo structure

	reads:
		range info structure
	
	writes:
		n comedi_krange structures to rangeinfo->range_ptr
*/
int do_rangeinfo_ioctl(comedi_device *dev,comedi_rangeinfo *arg)
{
	comedi_rangeinfo it;
	int minor,subd,chan;
	comedi_lrange *lr;
	comedi_subdevice *s;

	if(copy_from_user(&it,arg,sizeof(comedi_rangeinfo)))
		return -EFAULT;

	minor=(it.range_type>>28)&0xf;
	subd=(it.range_type>>24)&0xf;
	chan=(it.range_type>>16)&0xff;

	if(minor>COMEDI_NDEVICES)
		return -EINVAL;
	dev=comedi_get_device_by_minor(minor);
	if(!dev->attached)return -EINVAL;
	if(subd>=dev->n_subdevices)return -EINVAL;
	s=dev->subdevices+subd;
	if(s->range_table){
		lr=s->range_table;
	}else if(s->range_table_list){
		if(chan>=s->n_chan)return -EINVAL;
		lr=s->range_table_list[chan];
	}else{
		return -EINVAL;
	}

	if( RANGE_LENGTH(it.range_type) != lr->length){
		DPRINTK("wrong length %d should be %d (0x%08x)\n",
			RANGE_LENGTH(it.range_type),lr->length,it.range_type);
		return -EINVAL;
	}

	if(copy_to_user(it.range_ptr,lr->range,
		sizeof(comedi_krange)*lr->length))
		return -EFAULT;
	
	return 0;
}

static int aref_invalid( comedi_subdevice *s, unsigned int chanspec )
{
	unsigned int aref;

	// disable reporting invalid arefs... maybe someday
	return 0;

	aref = CR_AREF( chanspec );
	switch( aref )
	{
		case AREF_DIFF:
			if( s->subdev_flags & SDF_DIFF ) return 0;
			break;
		case AREF_COMMON:
			if( s->subdev_flags & SDF_COMMON ) return 0;
			break;
		case AREF_GROUND:
			if( s->subdev_flags & SDF_GROUND ) return 0;
			break;
		case AREF_OTHER:
			if( s->subdev_flags & SDF_OTHER ) return 0;
			break;
		default:
			break;
	}
	DPRINTK("subdevice does not support aref %i", aref);
	return 1;
}

/*
   This function checks each element in a channel/gain list to make
   make sure it is valid.
*/
int check_chanlist(comedi_subdevice *s,int n,unsigned int *chanlist)
{
	int i;
	int chan;


	if(s->range_table){
		for(i=0;i<n;i++)
			if(CR_CHAN(chanlist[i])>=s->n_chan ||
				CR_RANGE(chanlist[i])>=s->range_table->length ||
				aref_invalid( s, chanlist[i] ) ){
				rt_printk("bad chanlist[%d]=0x%08x n_chan=%d range length=%d\n",
					i,chanlist[i],s->n_chan,s->range_table->length);
#if 0
for(i=0;i<n;i++){
	printk("[%d]=0x%08x\n",i,chanlist[i]);
}
#endif
				return -EINVAL;
			}
	}else if(s->range_table_list){
		for(i=0;i<n;i++){
			chan=CR_CHAN(chanlist[i]);
			if(chan>=s->n_chan ||
				CR_RANGE(chanlist[i])>=s->range_table_list[chan]->length ||
				aref_invalid( s, chanlist[i] ) ){
				rt_printk("bad chanlist[%d]=0x%08x\n",i,chanlist[i]);
				return -EINVAL;
			}
		}
	}else{
		rt_printk("comedi: (bug) no range type list!\n");
		return -EINVAL;
	}
	return 0;
}