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 *it)
  50 {
  51         int subd, chan;
  52         const struct comedi_lrange *lr;
  53         struct comedi_subdevice *s;
  54
  55         subd = (it->range_type >> 24) & 0xf;
  56         chan = (it->range_type >> 16) & 0xff;
  57
  58         if (!dev->attached)
  59                 return -EINVAL;
  60         if (subd >= dev->n_subdevices)
  61                 return -EINVAL;
  62         s = &dev->subdevices[subd];
  63         if (s->range_table) {
  64                 lr = s->range_table;
  65         } else if (s->range_table_list) {
  66                 if (chan >= s->n_chan)
  67                         return -EINVAL;
  68                 lr = s->range_table_list[chan];
  69         } else {
  70                 return -EINVAL;
  71         }
  72
  73         if (RANGE_LENGTH(it->range_type) != lr->length) {
  74                 dev_dbg(dev->class_dev,
  75                         "wrong length %d should be %d (0x%08x)\n",
  76                         RANGE_LENGTH(it->range_type),
  77                         lr->length, it->range_type);
  78                 return -EINVAL;
  79         }
  80
  81         if (copy_to_user(it->range_ptr, lr->range,
  82                          sizeof(struct comedi_krange) * lr->length))
  83                 return -EFAULT;
  84
  85         return 0;
  86 }
  87
  88 /**
  89  * comedi_check_chanlist() - Validate each element in a chanlist.
  90  * @s: comedi_subdevice struct
  91  * @n: number of elements in the chanlist
  92  * @chanlist: the chanlist to validate
  93  *
  94  * Each element consists of a channel number, a range index, an analog
  95  * reference type and some flags, all packed into an unsigned int.
  96  *
  97  * This checks that the channel number and range index are supported by
  98  * the comedi subdevice.  It does not check whether the analog reference
  99  * type and the flags are supported.  Drivers that care should check those
 100  * themselves.
 101  *
 102  * Return: %0 if all @chanlist elements are valid (success),
 103  *         %-EINVAL if one or more elements are invalid.
 104  */
 105 int comedi_check_chanlist(struct comedi_subdevice *s, int n,
 106                           unsigned int *chanlist)
 107 {
 108         struct comedi_device *dev = s->device;
 109         unsigned int chanspec;
 110         int chan, range_len, i;
 111
 112         for (i = 0; i < n; i++) {
 113                 chanspec = chanlist[i];
 114                 chan = CR_CHAN(chanspec);
 115                 if (s->range_table)
 116                         range_len = s->range_table->length;
 117                 else if (s->range_table_list && chan < s->n_chan)
 118                         range_len = s->range_table_list[chan]->length;
 119                 else
 120                         range_len = 0;
 121                 if (chan >= s->n_chan ||
 122                     CR_RANGE(chanspec) >= range_len) {
 123                         dev_warn(dev->class_dev,
 124                                  "bad chanlist[%d]=0x%08x chan=%d range length=%d\n",
 125                                  i, chanspec, chan, range_len);
 126                         return -EINVAL;
 127                 }
 128         }
 129         return 0;
 130 }
 131 EXPORT_SYMBOL_GPL(comedi_check_chanlist);