range.c revision e42315177d278089ba7b1e623ecbd5b273b7e62b 
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 "comedidev.h"
25#include <linux/uaccess.h>
26
27const struct comedi_lrange range_bipolar10 = { 1, {BIP_RANGE(10)} };
28const struct comedi_lrange range_bipolar5 = { 1, {BIP_RANGE(5)} };
29const struct comedi_lrange range_bipolar2_5 = { 1, {BIP_RANGE(2.5)} };
30const struct comedi_lrange range_unipolar10 = { 1, {UNI_RANGE(10)} };
31const struct comedi_lrange range_unipolar5 = { 1, {UNI_RANGE(5)} };
32const struct comedi_lrange range_unknown = { 1, {{0, 1000000, UNIT_none} } };
33EXPORT_SYMBOL(range_bipolar10);
34EXPORT_SYMBOL(range_bipolar5);
35EXPORT_SYMBOL(range_bipolar2_5);
36EXPORT_SYMBOL(range_unipolar10);
37EXPORT_SYMBOL(range_unipolar5);
38EXPORT_SYMBOL(range_unknown);
39
40/*
41	COMEDI_RANGEINFO
42	range information ioctl
43
44	arg:
45		pointer to rangeinfo structure
46
47	reads:
48		range info structure
49
50	writes:
51		n struct comedi_krange structures to rangeinfo->range_ptr
52*/
53int do_rangeinfo_ioctl(struct comedi_device *dev, struct comedi_rangeinfo *arg)
54{
55	struct comedi_rangeinfo it;
56	int subd, chan;
57	const struct comedi_lrange *lr;
58	struct comedi_subdevice *s;
59
60	if (copy_from_user(&it, arg, sizeof(struct comedi_rangeinfo)))
61		return -EFAULT;
62	subd = (it.range_type >> 24) & 0xf;
63	chan = (it.range_type >> 16) & 0xff;
64
65	if (!dev->attached)
66		return -EINVAL;
67	if (subd >= dev->n_subdevices)
68		return -EINVAL;
69	s = dev->subdevices + subd;
70	if (s->range_table) {
71		lr = s->range_table;
72	} else if (s->range_table_list) {
73		if (chan >= s->n_chan)
74			return -EINVAL;
75		lr = s->range_table_list[chan];
76	} else {
77		return -EINVAL;
78	}
79
80	if (RANGE_LENGTH(it.range_type) != lr->length) {
81		DPRINTK("wrong length %d should be %d (0x%08x)\n",
82			RANGE_LENGTH(it.range_type), lr->length, it.range_type);
83		return -EINVAL;
84	}
85
86	if (copy_to_user(it.range_ptr, lr->range,
87			 sizeof(struct comedi_krange) * lr->length))
88		return -EFAULT;
89
90	return 0;
91}
92
93static int aref_invalid(struct comedi_subdevice *s, unsigned int chanspec)
94{
95	unsigned int aref;
96
97	/*  disable reporting invalid arefs... maybe someday */
98	return 0;
99
100	aref = CR_AREF(chanspec);
101	switch (aref) {
102	case AREF_DIFF:
103		if (s->subdev_flags & SDF_DIFF)
104			return 0;
105		break;
106	case AREF_COMMON:
107		if (s->subdev_flags & SDF_COMMON)
108			return 0;
109		break;
110	case AREF_GROUND:
111		if (s->subdev_flags & SDF_GROUND)
112			return 0;
113		break;
114	case AREF_OTHER:
115		if (s->subdev_flags & SDF_OTHER)
116			return 0;
117		break;
118	default:
119		break;
120	}
121	DPRINTK("subdevice does not support aref %i", aref);
122	return 1;
123}
124
125/*
126   This function checks each element in a channel/gain list to make
127   make sure it is valid.
128*/
129int check_chanlist(struct comedi_subdevice *s, int n, unsigned int *chanlist)
130{
131	int i;
132	int chan;
133
134	if (s->range_table) {
135		for (i = 0; i < n; i++)
136			if (CR_CHAN(chanlist[i]) >= s->n_chan ||
137			    CR_RANGE(chanlist[i]) >= s->range_table->length
138			    || aref_invalid(s, chanlist[i])) {
139				printk(KERN_ERR "bad chanlist[%d]=0x%08x "
140				       "in_chan=%d range length=%d\n", i,
141				       chanlist[i], s->n_chan,
142				       s->range_table->length);
143				return -EINVAL;
144			}
145	} else if (s->range_table_list) {
146		for (i = 0; i < n; i++) {
147			chan = CR_CHAN(chanlist[i]);
148			if (chan >= s->n_chan ||
149			    CR_RANGE(chanlist[i]) >=
150			    s->range_table_list[chan]->length
151			    || aref_invalid(s, chanlist[i])) {
152				printk(KERN_ERR "bad chanlist[%d]=0x%08x\n",
153				       i, chanlist[i]);
154				return -EINVAL;
155			}
156		}
157	} else {
158		printk(KERN_ERR "comedi: (bug) no range type list!\n");
159		return -EINVAL;
160	}
161	return 0;
162}
163