range.c revision 3b6b25b5ddf4485e89432a35a7d79d371ba6eba1 
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
28const struct comedi_lrange range_bipolar10 = { 1, {BIP_RANGE(10)} };
29EXPORT_SYMBOL(range_bipolar10);
30const struct comedi_lrange range_bipolar5 = { 1, {BIP_RANGE(5)} };
31EXPORT_SYMBOL(range_bipolar5);
32const struct comedi_lrange range_bipolar2_5 = { 1, {BIP_RANGE(2.5)} };
33EXPORT_SYMBOL(range_bipolar2_5);
34const struct comedi_lrange range_unipolar10 = { 1, {UNI_RANGE(10)} };
35EXPORT_SYMBOL(range_unipolar10);
36const struct comedi_lrange range_unipolar5 = { 1, {UNI_RANGE(5)} };
37EXPORT_SYMBOL(range_unipolar5);
38const struct comedi_lrange range_unknown = { 1, {{0, 1000000, UNIT_none} } };
39EXPORT_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*/
54int 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
95static 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*/
131int 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}
166EXPORT_SYMBOL(comedi_check_chanlist);
167