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linux
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
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 __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 */
108int 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}
134EXPORT_SYMBOL_GPL(comedi_check_chanlist);