drivers/staging/comedi/range.c

   1 /*
   2     module/range.c
   3     comedi routines for voltage ranges
   4
   5     COMEDI - Linux Control and Measurement Device Interface
   6     Copyright (C) 1997-8 David A. Schleef <ds@schleef.org>
   7
   8     This program is free software; you can redistribute it and/or modify
   9     it under the terms of the GNU General Public License as published by
  10     the Free Software Foundation; either version 2 of the License, or
  11     (at your option) any later version.
  12
  13     This program is distributed in the hope that it will be useful,
  14     but WITHOUT ANY WARRANTY; without even the implied warranty of
  15     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16     GNU General Public License for more details.
  17
  18     You should have received a copy of the GNU General Public License
  19     along with this program; if not, write to the Free Software
  20     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21
  22 */
  23
  24 #include <linux/uaccess.h>
  25 #include "comedidev.h"
  26 #include "internal.h"
  27
  28 const struct comedi_lrange range_bipolar10 = { 1, {BIP_RANGE(10)} };
  29 EXPORT_SYMBOL(range_bipolar10);
  30 const struct comedi_lrange range_bipolar5 = { 1, {BIP_RANGE(5)} };
  31 EXPORT_SYMBOL(range_bipolar5);
  32 const struct comedi_lrange range_bipolar2_5 = { 1, {BIP_RANGE(2.5)} };
  33 EXPORT_SYMBOL(range_bipolar2_5);
  34 const struct comedi_lrange range_unipolar10 = { 1, {UNI_RANGE(10)} };
  35 EXPORT_SYMBOL(range_unipolar10);
  36 const struct comedi_lrange range_unipolar5 = { 1, {UNI_RANGE(5)} };
  37 EXPORT_SYMBOL(range_unipolar5);
  38 const struct comedi_lrange range_unknown = { 1, {{0, 1000000, UNIT_none} } };
  39 EXPORT_SYMBOL(range_unknown);
  40
  41 /*
  42         COMEDI_RANGEINFO
  43         range information ioctl
  44
  45         arg:
  46                 pointer to rangeinfo structure
  47
  48         reads:
  49                 range info structure
  50
  51         writes:
  52                 n struct comedi_krange structures to rangeinfo->range_ptr
  53 */
  54 int do_rangeinfo_ioctl(struct comedi_device *dev,
  55                        struct comedi_rangeinfo __user *arg)
  56 {
  57         struct comedi_rangeinfo it;
  58         int subd, chan;
  59         const struct comedi_lrange *lr;
  60         struct comedi_subdevice *s;
  61
  62         if (copy_from_user(&it, arg, sizeof(struct comedi_rangeinfo)))
  63                 return -EFAULT;
  64         subd = (it.range_type >> 24) & 0xf;
  65         chan = (it.range_type >> 16) & 0xff;
  66
  67         if (!dev->attached)
  68                 return -EINVAL;
  69         if (subd >= dev->n_subdevices)
  70                 return -EINVAL;
  71         s = dev->subdevices + subd;
  72         if (s->range_table) {
  73                 lr = s->range_table;
  74         } else if (s->range_table_list) {
  75                 if (chan >= s->n_chan)
  76                         return -EINVAL;
  77                 lr = s->range_table_list[chan];
  78         } else {
  79                 return -EINVAL;
  80         }
  81
  82         if (RANGE_LENGTH(it.range_type) != lr->length) {
  83                 DPRINTK("wrong length %d should be %d (0x%08x)\n",
  84                         RANGE_LENGTH(it.range_type), lr->length, it.range_type);
  85                 return -EINVAL;
  86         }
  87
  88         if (copy_to_user(it.range_ptr, lr->range,
  89                          sizeof(struct comedi_krange) * lr->length))
  90                 return -EFAULT;
  91
  92         return 0;
  93 }
  94
  95 static int aref_invalid(struct comedi_subdevice *s, unsigned int chanspec)
  96 {
  97         unsigned int aref;
  98
  99         /*  disable reporting invalid arefs... maybe someday */
 100         return 0;
 101
 102         aref = CR_AREF(chanspec);
 103         switch (aref) {
 104         case AREF_DIFF:
 105                 if (s->subdev_flags & SDF_DIFF)
 106                         return 0;
 107                 break;
 108         case AREF_COMMON:
 109                 if (s->subdev_flags & SDF_COMMON)
 110                         return 0;
 111                 break;
 112         case AREF_GROUND:
 113                 if (s->subdev_flags & SDF_GROUND)
 114                         return 0;
 115                 break;
 116         case AREF_OTHER:
 117                 if (s->subdev_flags & SDF_OTHER)
 118                         return 0;
 119                 break;
 120         default:
 121                 break;
 122         }
 123         DPRINTK("subdevice does not support aref %i", aref);
 124         return 1;
 125 }
 126
 127 /*
 128    This function checks each element in a channel/gain list to make
 129    make sure it is valid.
 130 */
 131 int comedi_check_chanlist(struct comedi_subdevice *s, int n,
 132                           unsigned int *chanlist)
 133 {
 134         int i;
 135         int chan;
 136
 137         if (s->range_table) {
 138                 for (i = 0; i < n; i++)
 139                         if (CR_CHAN(chanlist[i]) >= s->n_chan ||
 140                             CR_RANGE(chanlist[i]) >= s->range_table->length
 141                             || aref_invalid(s, chanlist[i])) {
 142                                 printk(KERN_ERR "bad chanlist[%d]=0x%08x "
 143                                        "in_chan=%d range length=%d\n", i,
 144                                        chanlist[i], s->n_chan,
 145                                        s->range_table->length);
 146                                 return -EINVAL;
 147                         }
 148         } else if (s->range_table_list) {
 149                 for (i = 0; i < n; i++) {
 150                         chan = CR_CHAN(chanlist[i]);
 151                         if (chan >= s->n_chan ||
 152                             CR_RANGE(chanlist[i]) >=
 153                             s->range_table_list[chan]->length
 154                             || aref_invalid(s, chanlist[i])) {
 155                                 printk(KERN_ERR "bad chanlist[%d]=0x%08x\n",
 156                                        i, chanlist[i]);
 157                                 return -EINVAL;
 158                         }
 159                 }
 160         } else {
 161                 printk(KERN_ERR "comedi: (bug) no range type list!\n");
 162                 return -EINVAL;
 163         }
 164         return 0;
 165 }
 166 EXPORT_SYMBOL(comedi_check_chanlist);