LXR linux/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
  28const struct comedi_lrange range_bipolar10 = { 1, {BIP_RANGE(10)} };
  29EXPORT_SYMBOL(range_bipolar10);
  30const struct comedi_lrange range_bipolar5 = { 1, {BIP_RANGE(5)} };
  31EXPORT_SYMBOL(range_bipolar5);
  32const struct comedi_lrange range_bipolar2_5 = { 1, {BIP_RANGE(2.5)} };
  33EXPORT_SYMBOL(range_bipolar2_5);
  34const struct comedi_lrange range_unipolar10 = { 1, {UNI_RANGE(10)} };
  35EXPORT_SYMBOL(range_unipolar10);
  36const struct comedi_lrange range_unipolar5 = { 1, {UNI_RANGE(5)} };
  37EXPORT_SYMBOL(range_unipolar5);
  38const struct comedi_lrange range_unknown = { 1, {{0, 1000000, UNIT_none} } };
  39EXPORT_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*/
  54int 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
  95static 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*/
 131int 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}
 166EXPORT_SYMBOL(comedi_check_chanlist);
 167