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
  19 #include <linux/uaccess.h>
  20 #include "comedidev.h"
  21 #include "comedi_internal.h"
  22
  23 const struct comedi_lrange range_bipolar10 = { 1, {BIP_RANGE(10)} };
  24 EXPORT_SYMBOL_GPL(range_bipolar10);
  25 const struct comedi_lrange range_bipolar5 = { 1, {BIP_RANGE(5)} };
  26 EXPORT_SYMBOL_GPL(range_bipolar5);
  27 const struct comedi_lrange range_bipolar2_5 = { 1, {BIP_RANGE(2.5)} };
  28 EXPORT_SYMBOL_GPL(range_bipolar2_5);
  29 const struct comedi_lrange range_unipolar10 = { 1, {UNI_RANGE(10)} };
  30 EXPORT_SYMBOL_GPL(range_unipolar10);
  31 const struct comedi_lrange range_unipolar5 = { 1, {UNI_RANGE(5)} };
  32 EXPORT_SYMBOL_GPL(range_unipolar5);
  33 const struct comedi_lrange range_unipolar2_5 = { 1, {UNI_RANGE(2.5)} };
  34 EXPORT_SYMBOL_GPL(range_unipolar2_5);
  35 const struct comedi_lrange range_0_20mA = { 1, {RANGE_mA(0, 20)} };
  36 EXPORT_SYMBOL_GPL(range_0_20mA);
  37 const struct comedi_lrange range_4_20mA = { 1, {RANGE_mA(4, 20)} };
  38 EXPORT_SYMBOL_GPL(range_4_20mA);
  39 const struct comedi_lrange range_0_32mA = { 1, {RANGE_mA(0, 32)} };
  40 EXPORT_SYMBOL_GPL(range_0_32mA);
  41 const struct comedi_lrange range_unknown = { 1, {{0, 1000000, UNIT_none} } };
  42 EXPORT_SYMBOL_GPL(range_unknown);
  43
  44 /*
  45         COMEDI_RANGEINFO
  46         range information ioctl
  47
  48         arg:
  49                 pointer to rangeinfo structure
  50
  51         reads:
  52                 range info structure
  53
  54         writes:
  55                 n struct comedi_krange structures to rangeinfo->range_ptr
  56 */
  57 int do_rangeinfo_ioctl(struct comedi_device *dev,
  58                        struct comedi_rangeinfo __user *arg)
  59 {
  60         struct comedi_rangeinfo it;
  61         int subd, chan;
  62         const struct comedi_lrange *lr;
  63         struct comedi_subdevice *s;
  64
  65         if (copy_from_user(&it, arg, sizeof(struct comedi_rangeinfo)))
  66                 return -EFAULT;
  67         subd = (it.range_type >> 24) & 0xf;
  68         chan = (it.range_type >> 16) & 0xff;
  69
  70         if (!dev->attached)
  71                 return -EINVAL;
  72         if (subd >= dev->n_subdevices)
  73                 return -EINVAL;
  74         s = &dev->subdevices[subd];
  75         if (s->range_table) {
  76                 lr = s->range_table;
  77         } else if (s->range_table_list) {
  78                 if (chan >= s->n_chan)
  79                         return -EINVAL;
  80                 lr = s->range_table_list[chan];
  81         } else {
  82                 return -EINVAL;
  83         }
  84
  85         if (RANGE_LENGTH(it.range_type) != lr->length) {
  86                 dev_dbg(dev->class_dev,
  87                         "wrong length %d should be %d (0x%08x)\n",
  88                         RANGE_LENGTH(it.range_type),
  89                         lr->length, it.range_type);
  90                 return -EINVAL;
  91         }
  92
  93         if (copy_to_user(it.range_ptr, lr->range,
  94                          sizeof(struct comedi_krange) * lr->length))
  95                 return -EFAULT;
  96
  97         return 0;
  98 }
  99
 100 static int aref_invalid(struct comedi_subdevice *s, unsigned int chanspec)
 101 {
 102         unsigned int aref;
 103
 104         /*  disable reporting invalid arefs... maybe someday */
 105         return 0;
 106
 107         aref = CR_AREF(chanspec);
 108         switch (aref) {
 109         case AREF_DIFF:
 110                 if (s->subdev_flags & SDF_DIFF)
 111                         return 0;
 112                 break;
 113         case AREF_COMMON:
 114                 if (s->subdev_flags & SDF_COMMON)
 115                         return 0;
 116                 break;
 117         case AREF_GROUND:
 118                 if (s->subdev_flags & SDF_GROUND)
 119                         return 0;
 120                 break;
 121         case AREF_OTHER:
 122                 if (s->subdev_flags & SDF_OTHER)
 123                         return 0;
 124                 break;
 125         default:
 126                 break;
 127         }
 128         dev_dbg(s->device->class_dev, "subdevice does not support aref %i",
 129                 aref);
 130         return 1;
 131 }
 132
 133 /**
 134  * comedi_check_chanlist() - Validate each element in a chanlist.
 135  * @s: comedi_subdevice struct
 136  * @n: number of elements in the chanlist
 137  * @chanlist: the chanlist to validate
 138 */
 139 int comedi_check_chanlist(struct comedi_subdevice *s, int n,
 140                           unsigned int *chanlist)
 141 {
 142         struct comedi_device *dev = s->device;
 143         unsigned int chanspec;
 144         int chan, range_len, i;
 145
 146         if (s->range_table || s->range_table_list) {
 147                 for (i = 0; i < n; i++) {
 148                         chanspec = chanlist[i];
 149                         chan = CR_CHAN(chanspec);
 150                         if (s->range_table)
 151                                 range_len = s->range_table->length;
 152                         else if (s->range_table_list && chan < s->n_chan)
 153                                 range_len = s->range_table_list[chan]->length;
 154                         else
 155                                 range_len = 0;
 156                         if (chan >= s->n_chan ||
 157                             CR_RANGE(chanspec) >= range_len ||
 158                             aref_invalid(s, chanspec)) {
 159                                 dev_warn(dev->class_dev,
 160                                          "bad chanlist[%d]=0x%08x chan=%d range length=%d\n",
 161                                          i, chanspec, chan, range_len);
 162                                 return -EINVAL;
 163                         }
 164                 }
 165         } else {
 166                 dev_err(dev->class_dev, "(bug) no range type list!\n");
 167                 return -EINVAL;
 168         }
 169         return 0;
 170 }
 171 EXPORT_SYMBOL_GPL(comedi_check_chanlist);