drivers/staging/comedi/range.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * comedi/range.c
   4  * comedi routines for voltage ranges
   5  *
   6  * COMEDI - Linux Control and Measurement Device Interface
   7  * Copyright (C) 1997-8 David A. Schleef <ds@schleef.org>
   8  */
   9
  10 #include <linux/uaccess.h>
  11 #include "comedidev.h"
  12 #include "comedi_internal.h"
  13
  14 const struct comedi_lrange range_bipolar10 = { 1, {BIP_RANGE(10)} };
  15 EXPORT_SYMBOL_GPL(range_bipolar10);
  16 const struct comedi_lrange range_bipolar5 = { 1, {BIP_RANGE(5)} };
  17 EXPORT_SYMBOL_GPL(range_bipolar5);
  18 const struct comedi_lrange range_bipolar2_5 = { 1, {BIP_RANGE(2.5)} };
  19 EXPORT_SYMBOL_GPL(range_bipolar2_5);
  20 const struct comedi_lrange range_unipolar10 = { 1, {UNI_RANGE(10)} };
  21 EXPORT_SYMBOL_GPL(range_unipolar10);
  22 const struct comedi_lrange range_unipolar5 = { 1, {UNI_RANGE(5)} };
  23 EXPORT_SYMBOL_GPL(range_unipolar5);
  24 const struct comedi_lrange range_unipolar2_5 = { 1, {UNI_RANGE(2.5)} };
  25 EXPORT_SYMBOL_GPL(range_unipolar2_5);
  26 const struct comedi_lrange range_0_20mA = { 1, {RANGE_mA(0, 20)} };
  27 EXPORT_SYMBOL_GPL(range_0_20mA);
  28 const struct comedi_lrange range_4_20mA = { 1, {RANGE_mA(4, 20)} };
  29 EXPORT_SYMBOL_GPL(range_4_20mA);
  30 const struct comedi_lrange range_0_32mA = { 1, {RANGE_mA(0, 32)} };
  31 EXPORT_SYMBOL_GPL(range_0_32mA);
  32 const struct comedi_lrange range_unknown = { 1, {{0, 1000000, UNIT_none} } };
  33 EXPORT_SYMBOL_GPL(range_unknown);
  34
  35 /*
  36  * COMEDI_RANGEINFO ioctl
  37  * range information
  38  *
  39  * arg:
  40  *      pointer to comedi_rangeinfo structure
  41  *
  42  * reads:
  43  *      comedi_rangeinfo structure
  44  *
  45  * writes:
  46  *      array of comedi_krange structures to rangeinfo->range_ptr pointer
  47  */
  48 int do_rangeinfo_ioctl(struct comedi_device *dev,
  49                        struct comedi_rangeinfo __user *arg)
  50 {
  51         struct comedi_rangeinfo it;
  52         int subd, chan;
  53         const struct comedi_lrange *lr;
  54         struct comedi_subdevice *s;
  55
  56         if (copy_from_user(&it, arg, sizeof(struct comedi_rangeinfo)))
  57                 return -EFAULT;
  58         subd = (it.range_type >> 24) & 0xf;
  59         chan = (it.range_type >> 16) & 0xff;
  60
  61         if (!dev->attached)
  62                 return -EINVAL;
  63         if (subd >= dev->n_subdevices)
  64                 return -EINVAL;
  65         s = &dev->subdevices[subd];
  66         if (s->range_table) {
  67                 lr = s->range_table;
  68         } else if (s->range_table_list) {
  69                 if (chan >= s->n_chan)
  70                         return -EINVAL;
  71                 lr = s->range_table_list[chan];
  72         } else {
  73                 return -EINVAL;
  74         }
  75
  76         if (RANGE_LENGTH(it.range_type) != lr->length) {
  77                 dev_dbg(dev->class_dev,
  78                         "wrong length %d should be %d (0x%08x)\n",
  79                         RANGE_LENGTH(it.range_type),
  80                         lr->length, it.range_type);
  81                 return -EINVAL;
  82         }
  83
  84         if (copy_to_user(it.range_ptr, lr->range,
  85                          sizeof(struct comedi_krange) * lr->length))
  86                 return -EFAULT;
  87
  88         return 0;
  89 }
  90
  91 /**
  92  * comedi_check_chanlist() - Validate each element in a chanlist.
  93  * @s: comedi_subdevice struct
  94  * @n: number of elements in the chanlist
  95  * @chanlist: the chanlist to validate
  96  *
  97  * Each element consists of a channel number, a range index, an analog
  98  * reference type and some flags, all packed into an unsigned int.
  99  *
 100  * This checks that the channel number and range index are supported by
 101  * the comedi subdevice.  It does not check whether the analog reference
 102  * type and the flags are supported.  Drivers that care should check those
 103  * themselves.
 104  *
 105  * Return: %0 if all @chanlist elements are valid (success),
 106  *         %-EINVAL if one or more elements are invalid.
 107  */
 108 int comedi_check_chanlist(struct comedi_subdevice *s, int n,
 109                           unsigned int *chanlist)
 110 {
 111         struct comedi_device *dev = s->device;
 112         unsigned int chanspec;
 113         int chan, range_len, i;
 114
 115         for (i = 0; i < n; i++) {
 116                 chanspec = chanlist[i];
 117                 chan = CR_CHAN(chanspec);
 118                 if (s->range_table)
 119                         range_len = s->range_table->length;
 120                 else if (s->range_table_list && chan < s->n_chan)
 121                         range_len = s->range_table_list[chan]->length;
 122                 else
 123                         range_len = 0;
 124                 if (chan >= s->n_chan ||
 125                     CR_RANGE(chanspec) >= range_len) {
 126                         dev_warn(dev->class_dev,
 127                                  "bad chanlist[%d]=0x%08x chan=%d range length=%d\n",
 128                                  i, chanspec, chan, range_len);
 129                         return -EINVAL;
 130                 }
 131         }
 132         return 0;
 133 }
 134 EXPORT_SYMBOL_GPL(comedi_check_chanlist);