Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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kernel
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linux
1/*
2 * comedi/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
19#include <linux/uaccess.h>
20#include "comedidev.h"
21#include "comedi_internal.h"
22
23const struct comedi_lrange range_bipolar10 = { 1, {BIP_RANGE(10)} };
24EXPORT_SYMBOL_GPL(range_bipolar10);
25const struct comedi_lrange range_bipolar5 = { 1, {BIP_RANGE(5)} };
26EXPORT_SYMBOL_GPL(range_bipolar5);
27const struct comedi_lrange range_bipolar2_5 = { 1, {BIP_RANGE(2.5)} };
28EXPORT_SYMBOL_GPL(range_bipolar2_5);
29const struct comedi_lrange range_unipolar10 = { 1, {UNI_RANGE(10)} };
30EXPORT_SYMBOL_GPL(range_unipolar10);
31const struct comedi_lrange range_unipolar5 = { 1, {UNI_RANGE(5)} };
32EXPORT_SYMBOL_GPL(range_unipolar5);
33const struct comedi_lrange range_unipolar2_5 = { 1, {UNI_RANGE(2.5)} };
34EXPORT_SYMBOL_GPL(range_unipolar2_5);
35const struct comedi_lrange range_0_20mA = { 1, {RANGE_mA(0, 20)} };
36EXPORT_SYMBOL_GPL(range_0_20mA);
37const struct comedi_lrange range_4_20mA = { 1, {RANGE_mA(4, 20)} };
38EXPORT_SYMBOL_GPL(range_4_20mA);
39const struct comedi_lrange range_0_32mA = { 1, {RANGE_mA(0, 32)} };
40EXPORT_SYMBOL_GPL(range_0_32mA);
41const struct comedi_lrange range_unknown = { 1, {{0, 1000000, UNIT_none} } };
42EXPORT_SYMBOL_GPL(range_unknown);
43
44/*
45 * COMEDI_RANGEINFO ioctl
46 * range information
47 *
48 * arg:
49 * pointer to comedi_rangeinfo structure
50 *
51 * reads:
52 * comedi_rangeinfo structure
53 *
54 * writes:
55 * array of comedi_krange structures to rangeinfo->range_ptr pointer
56 */
57int do_rangeinfo_ioctl(struct comedi_device *dev,
58 struct comedi_rangeinfo __user *arg)
59{
60 struct comedi_rangeinfo it;
61 int subd, chan;
62 const struct comedi_lrange *lr;
63 struct comedi_subdevice *s;
64
65 if (copy_from_user(&it, arg, sizeof(struct comedi_rangeinfo)))
66 return -EFAULT;
67 subd = (it.range_type >> 24) & 0xf;
68 chan = (it.range_type >> 16) & 0xff;
69
70 if (!dev->attached)
71 return -EINVAL;
72 if (subd >= dev->n_subdevices)
73 return -EINVAL;
74 s = &dev->subdevices[subd];
75 if (s->range_table) {
76 lr = s->range_table;
77 } else if (s->range_table_list) {
78 if (chan >= s->n_chan)
79 return -EINVAL;
80 lr = s->range_table_list[chan];
81 } else {
82 return -EINVAL;
83 }
84
85 if (RANGE_LENGTH(it.range_type) != lr->length) {
86 dev_dbg(dev->class_dev,
87 "wrong length %d should be %d (0x%08x)\n",
88 RANGE_LENGTH(it.range_type),
89 lr->length, it.range_type);
90 return -EINVAL;
91 }
92
93 if (copy_to_user(it.range_ptr, lr->range,
94 sizeof(struct comedi_krange) * lr->length))
95 return -EFAULT;
96
97 return 0;
98}
99
100/**
101 * comedi_check_chanlist() - Validate each element in a chanlist.
102 * @s: comedi_subdevice struct
103 * @n: number of elements in the chanlist
104 * @chanlist: the chanlist to validate
105 *
106 * Each element consists of a channel number, a range index, an analog
107 * reference type and some flags, all packed into an unsigned int.
108 *
109 * This checks that the channel number and range index are supported by
110 * the comedi subdevice. It does not check whether the analog reference
111 * type and the flags are supported. Drivers that care should check those
112 * themselves.
113 *
114 * Return: %0 if all @chanlist elements are valid (success),
115 * %-EINVAL if one or more elements are invalid.
116 */
117int comedi_check_chanlist(struct comedi_subdevice *s, int n,
118 unsigned int *chanlist)
119{
120 struct comedi_device *dev = s->device;
121 unsigned int chanspec;
122 int chan, range_len, i;
123
124 for (i = 0; i < n; i++) {
125 chanspec = chanlist[i];
126 chan = CR_CHAN(chanspec);
127 if (s->range_table)
128 range_len = s->range_table->length;
129 else if (s->range_table_list && chan < s->n_chan)
130 range_len = s->range_table_list[chan]->length;
131 else
132 range_len = 0;
133 if (chan >= s->n_chan ||
134 CR_RANGE(chanspec) >= range_len) {
135 dev_warn(dev->class_dev,
136 "bad chanlist[%d]=0x%08x chan=%d range length=%d\n",
137 i, chanspec, chan, range_len);
138 return -EINVAL;
139 }
140 }
141 return 0;
142}
143EXPORT_SYMBOL_GPL(comedi_check_chanlist);