range.c revision 1b2e434e1b46c0414e9645cce6179e0fef5e388b 
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 <asm/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} } };
33
34/*
35	COMEDI_RANGEINFO
36	range information ioctl
37
38	arg:
39		pointer to rangeinfo structure
40
41	reads:
42		range info structure
43
44	writes:
45		n struct comedi_krange structures to rangeinfo->range_ptr
46*/
47int do_rangeinfo_ioctl(struct comedi_device *dev, struct comedi_rangeinfo *arg)
48{
49	struct comedi_rangeinfo it;
50	int subd, chan;
51	const struct comedi_lrange *lr;
52	struct comedi_subdevice *s;
53
54	if (copy_from_user(&it, arg, sizeof(struct comedi_rangeinfo)))
55		return -EFAULT;
56	subd = (it.range_type >> 24) & 0xf;
57	chan = (it.range_type >> 16) & 0xff;
58
59	if (!dev->attached)
60		return -EINVAL;
61	if (subd >= dev->n_subdevices)
62		return -EINVAL;
63	s = dev->subdevices + subd;
64	if (s->range_table) {
65		lr = s->range_table;
66	} else if (s->range_table_list) {
67		if (chan >= s->n_chan)
68			return -EINVAL;
69		lr = s->range_table_list[chan];
70	} else {
71		return -EINVAL;
72	}
73
74	if (RANGE_LENGTH(it.range_type) != lr->length) {
75		DPRINTK("wrong length %d should be %d (0x%08x)\n",
76			RANGE_LENGTH(it.range_type), lr->length, it.range_type);
77		return -EINVAL;
78	}
79
80	if (copy_to_user(it.range_ptr, lr->range,
81			 sizeof(struct comedi_krange) * lr->length))
82		return -EFAULT;
83
84	return 0;
85}
86
87static int aref_invalid(struct comedi_subdevice *s, unsigned int chanspec)
88{
89	unsigned int aref;
90
91	/*  disable reporting invalid arefs... maybe someday */
92	return 0;
93
94	aref = CR_AREF(chanspec);
95	switch (aref) {
96	case AREF_DIFF:
97		if (s->subdev_flags & SDF_DIFF)
98			return 0;
99		break;
100	case AREF_COMMON:
101		if (s->subdev_flags & SDF_COMMON)
102			return 0;
103		break;
104	case AREF_GROUND:
105		if (s->subdev_flags & SDF_GROUND)
106			return 0;
107		break;
108	case AREF_OTHER:
109		if (s->subdev_flags & SDF_OTHER)
110			return 0;
111		break;
112	default:
113		break;
114	}
115	DPRINTK("subdevice does not support aref %i", aref);
116	return 1;
117}
118
119/*
120   This function checks each element in a channel/gain list to make
121   make sure it is valid.
122*/
123int check_chanlist(struct comedi_subdevice *s, int n, unsigned int *chanlist)
124{
125	int i;
126	int chan;
127
128	if (s->range_table) {
129		for (i = 0; i < n; i++)
130			if (CR_CHAN(chanlist[i]) >= s->n_chan ||
131			    CR_RANGE(chanlist[i]) >= s->range_table->length
132			    || aref_invalid(s, chanlist[i])) {
133				printk
134				    ("bad chanlist[%d]=0x%08x n_chan=%d range length=%d\n",
135				     i, chanlist[i], s->n_chan,
136				     s->range_table->length);
137#if 0
138				for (i = 0; i < n; i++)
139					printk("[%d]=0x%08x\n", i, chanlist[i]);
140#endif
141				return -EINVAL;
142			}
143	} else if (s->range_table_list) {
144		for (i = 0; i < n; i++) {
145			chan = CR_CHAN(chanlist[i]);
146			if (chan >= s->n_chan ||
147			    CR_RANGE(chanlist[i]) >=
148			    s->range_table_list[chan]->length
149			    || aref_invalid(s, chanlist[i])) {
150				printk("bad chanlist[%d]=0x%08x\n", i,
151				       chanlist[i]);
152				return -EINVAL;
153			}
154		}
155	} else {
156		printk("comedi: (bug) no range type list!\n");
157		return -EINVAL;
158	}
159	return 0;
160}
161