1 /*
2     module/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     You should have received a copy of the GNU General Public License
19     along with this program; if not, write to the Free Software
20     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21 
22 */
23 
24 #include <linux/uaccess.h>
25 #include "comedidev.h"
26 #include "internal.h"
27 
28 const struct comedi_lrange range_bipolar10 = { 1, {BIP_RANGE(10)} };
29 EXPORT_SYMBOL(range_bipolar10);
30 const struct comedi_lrange range_bipolar5 = { 1, {BIP_RANGE(5)} };
31 EXPORT_SYMBOL(range_bipolar5);
32 const struct comedi_lrange range_bipolar2_5 = { 1, {BIP_RANGE(2.5)} };
33 EXPORT_SYMBOL(range_bipolar2_5);
34 const struct comedi_lrange range_unipolar10 = { 1, {UNI_RANGE(10)} };
35 EXPORT_SYMBOL(range_unipolar10);
36 const struct comedi_lrange range_unipolar5 = { 1, {UNI_RANGE(5)} };
37 EXPORT_SYMBOL(range_unipolar5);
38 const struct comedi_lrange range_unknown = { 1, {{0, 1000000, UNIT_none} } };
39 EXPORT_SYMBOL(range_unknown);
40 
41 /*
42 	COMEDI_RANGEINFO
43 	range information ioctl
44 
45 	arg:
46 		pointer to rangeinfo structure
47 
48 	reads:
49 		range info structure
50 
51 	writes:
52 		n struct comedi_krange structures to rangeinfo->range_ptr
53 */
do_rangeinfo_ioctl(struct comedi_device * dev,struct comedi_rangeinfo __user * arg)54 int do_rangeinfo_ioctl(struct comedi_device *dev,
55 		       struct comedi_rangeinfo __user *arg)
56 {
57 	struct comedi_rangeinfo it;
58 	int subd, chan;
59 	const struct comedi_lrange *lr;
60 	struct comedi_subdevice *s;
61 
62 	if (copy_from_user(&it, arg, sizeof(struct comedi_rangeinfo)))
63 		return -EFAULT;
64 	subd = (it.range_type >> 24) & 0xf;
65 	chan = (it.range_type >> 16) & 0xff;
66 
67 	if (!dev->attached)
68 		return -EINVAL;
69 	if (subd >= dev->n_subdevices)
70 		return -EINVAL;
71 	s = dev->subdevices + subd;
72 	if (s->range_table) {
73 		lr = s->range_table;
74 	} else if (s->range_table_list) {
75 		if (chan >= s->n_chan)
76 			return -EINVAL;
77 		lr = s->range_table_list[chan];
78 	} else {
79 		return -EINVAL;
80 	}
81 
82 	if (RANGE_LENGTH(it.range_type) != lr->length) {
83 		DPRINTK("wrong length %d should be %d (0x%08x)\n",
84 			RANGE_LENGTH(it.range_type), lr->length, it.range_type);
85 		return -EINVAL;
86 	}
87 
88 	if (copy_to_user(it.range_ptr, lr->range,
89 			 sizeof(struct comedi_krange) * lr->length))
90 		return -EFAULT;
91 
92 	return 0;
93 }
94 
aref_invalid(struct comedi_subdevice * s,unsigned int chanspec)95 static int aref_invalid(struct comedi_subdevice *s, unsigned int chanspec)
96 {
97 	unsigned int aref;
98 
99 	/*  disable reporting invalid arefs... maybe someday */
100 	return 0;
101 
102 	aref = CR_AREF(chanspec);
103 	switch (aref) {
104 	case AREF_DIFF:
105 		if (s->subdev_flags & SDF_DIFF)
106 			return 0;
107 		break;
108 	case AREF_COMMON:
109 		if (s->subdev_flags & SDF_COMMON)
110 			return 0;
111 		break;
112 	case AREF_GROUND:
113 		if (s->subdev_flags & SDF_GROUND)
114 			return 0;
115 		break;
116 	case AREF_OTHER:
117 		if (s->subdev_flags & SDF_OTHER)
118 			return 0;
119 		break;
120 	default:
121 		break;
122 	}
123 	DPRINTK("subdevice does not support aref %i", aref);
124 	return 1;
125 }
126 
127 /*
128    This function checks each element in a channel/gain list to make
129    make sure it is valid.
130 */
comedi_check_chanlist(struct comedi_subdevice * s,int n,unsigned int * chanlist)131 int comedi_check_chanlist(struct comedi_subdevice *s, int n,
132 			  unsigned int *chanlist)
133 {
134 	int i;
135 	int chan;
136 
137 	if (s->range_table) {
138 		for (i = 0; i < n; i++)
139 			if (CR_CHAN(chanlist[i]) >= s->n_chan ||
140 			    CR_RANGE(chanlist[i]) >= s->range_table->length
141 			    || aref_invalid(s, chanlist[i])) {
142 				printk(KERN_ERR "bad chanlist[%d]=0x%08x "
143 				       "in_chan=%d range length=%d\n", i,
144 				       chanlist[i], s->n_chan,
145 				       s->range_table->length);
146 				return -EINVAL;
147 			}
148 	} else if (s->range_table_list) {
149 		for (i = 0; i < n; i++) {
150 			chan = CR_CHAN(chanlist[i]);
151 			if (chan >= s->n_chan ||
152 			    CR_RANGE(chanlist[i]) >=
153 			    s->range_table_list[chan]->length
154 			    || aref_invalid(s, chanlist[i])) {
155 				printk(KERN_ERR "bad chanlist[%d]=0x%08x\n",
156 				       i, chanlist[i]);
157 				return -EINVAL;
158 			}
159 		}
160 	} else {
161 		printk(KERN_ERR "comedi: (bug) no range type list!\n");
162 		return -EINVAL;
163 	}
164 	return 0;
165 }
166 EXPORT_SYMBOL(comedi_check_chanlist);
167