range.c

Go to the documentation of this file.

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

    COMEDI - Linux Control and Measurement Device Interface
    Copyright (C) 1997-8 David A. Schleef <[email protected]>

    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/uaccess.h>
#include "comedidev.h"
#include "comedi_internal.h"

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

/*
    COMEDI_RANGEINFO
    range information ioctl

    arg:
        pointer to rangeinfo structure

    reads:
        range info structure

    writes:
        n struct comedi_krange structures to rangeinfo->range_ptr
*/
int do_rangeinfo_ioctl(struct comedi_device *dev,
               struct comedi_rangeinfo __user *arg)
{
    struct comedi_rangeinfo it;
    int subd, chan;
    const struct comedi_lrange *lr;
    struct comedi_subdevice *s;

    if (copy_from_user(&it, arg, sizeof(struct comedi_rangeinfo)))
        return -EFAULT;
    subd = (it.range_type >> 24) & 0xf;
    chan = (it.range_type >> 16) & 0xff;

    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(struct comedi_krange) * lr->length))
        return -EFAULT;

    return 0;
}

static int aref_invalid(struct 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 comedi_check_chanlist(struct comedi_subdevice *s, int n,
              unsigned int *chanlist)
{
    struct comedi_device *dev = s->device;
    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])) {
                dev_warn(dev->class_dev,
                     "bad chanlist[%d]=0x%08x in_chan=%d range length=%d\n",
                     i, chanlist[i], s->n_chan,
                     s->range_table->length);
                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])) {
                dev_warn(dev->class_dev,
                     "bad chanlist[%d]=0x%08x\n",
                     i, chanlist[i]);
                return -EINVAL;
            }
        }
    } else {
        dev_err(dev->class_dev, "(bug) no range type list!\n");
        return -EINVAL;
    }
    return 0;
}
EXPORT_SYMBOL(comedi_check_chanlist);