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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 <[email protected]>
8 */
9
10#include <linux/uaccess.h>
11#include <linux/comedi/comedidev.h>
12#include "comedi_internal.h"
13
14const struct comedi_lrange range_bipolar10 = { 1, {BIP_RANGE(10)} };
15EXPORT_SYMBOL_GPL(range_bipolar10);
16const struct comedi_lrange range_bipolar5 = { 1, {BIP_RANGE(5)} };
17EXPORT_SYMBOL_GPL(range_bipolar5);
18const struct comedi_lrange range_bipolar2_5 = { 1, {BIP_RANGE(2.5)} };
19EXPORT_SYMBOL_GPL(range_bipolar2_5);
20const struct comedi_lrange range_unipolar10 = { 1, {UNI_RANGE(10)} };
21EXPORT_SYMBOL_GPL(range_unipolar10);
22const struct comedi_lrange range_unipolar5 = { 1, {UNI_RANGE(5)} };
23EXPORT_SYMBOL_GPL(range_unipolar5);
24const struct comedi_lrange range_unipolar2_5 = { 1, {UNI_RANGE(2.5)} };
25EXPORT_SYMBOL_GPL(range_unipolar2_5);
26const struct comedi_lrange range_0_20mA = { 1, {RANGE_mA(0, 20)} };
27EXPORT_SYMBOL_GPL(range_0_20mA);
28const struct comedi_lrange range_4_20mA = { 1, {RANGE_mA(4, 20)} };
29EXPORT_SYMBOL_GPL(range_4_20mA);
30const struct comedi_lrange range_0_32mA = { 1, {RANGE_mA(0, 32)} };
31EXPORT_SYMBOL_GPL(range_0_32mA);
32const struct comedi_lrange range_unknown = { 1, {{0, 1000000, UNIT_none} } };
33EXPORT_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 */
48int 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) & 0xff;
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 */
105int 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}
131EXPORT_SYMBOL_GPL(comedi_check_chanlist);