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  */
do_rangeinfo_ioctl(struct comedi_device * dev,struct comedi_rangeinfo * it)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  */
comedi_check_chanlist(struct comedi_subdevice * s,int n,unsigned int * chanlist)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);
132