summaryrefslogtreecommitdiffstats
path: root/drivers/comedi/kcomedilib/kcomedilib_main.c
blob: 43fbe1a63b14f852c303bf05aa46ffb7ec7201fa (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
// SPDX-License-Identifier: GPL-2.0+
/*
 * kcomedilib/kcomedilib.c
 * a comedlib interface for kernel modules
 *
 * COMEDI - Linux Control and Measurement Device Interface
 * Copyright (C) 1997-2000 David A. Schleef <ds@schleef.org>
 */

#include <linux/module.h>

#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/io.h>

#include <linux/comedi.h>
#include <linux/comedi/comedidev.h>
#include <linux/comedi/comedilib.h>

MODULE_AUTHOR("David Schleef <ds@schleef.org>");
MODULE_DESCRIPTION("Comedi kernel library");
MODULE_LICENSE("GPL");

struct comedi_device *comedi_open(const char *filename)
{
	struct comedi_device *dev, *retval = NULL;
	unsigned int minor;

	if (strncmp(filename, "/dev/comedi", 11) != 0)
		return NULL;

	if (kstrtouint(filename + 11, 0, &minor))
		return NULL;

	if (minor >= COMEDI_NUM_BOARD_MINORS)
		return NULL;

	dev = comedi_dev_get_from_minor(minor);
	if (!dev)
		return NULL;

	down_read(&dev->attach_lock);
	if (dev->attached)
		retval = dev;
	else
		retval = NULL;
	up_read(&dev->attach_lock);

	if (!retval)
		comedi_dev_put(dev);

	return retval;
}
EXPORT_SYMBOL_GPL(comedi_open);

int comedi_close(struct comedi_device *dev)
{
	comedi_dev_put(dev);
	return 0;
}
EXPORT_SYMBOL_GPL(comedi_close);

static int comedi_do_insn(struct comedi_device *dev,
			  struct comedi_insn *insn,
			  unsigned int *data)
{
	struct comedi_subdevice *s;
	int ret;

	mutex_lock(&dev->mutex);

	if (!dev->attached) {
		ret = -EINVAL;
		goto error;
	}

	/* a subdevice instruction */
	if (insn->subdev >= dev->n_subdevices) {
		ret = -EINVAL;
		goto error;
	}
	s = &dev->subdevices[insn->subdev];

	if (s->type == COMEDI_SUBD_UNUSED) {
		dev_err(dev->class_dev,
			"%d not usable subdevice\n", insn->subdev);
		ret = -EIO;
		goto error;
	}

	/* XXX check lock */

	ret = comedi_check_chanlist(s, 1, &insn->chanspec);
	if (ret < 0) {
		dev_err(dev->class_dev, "bad chanspec\n");
		ret = -EINVAL;
		goto error;
	}

	if (s->busy) {
		ret = -EBUSY;
		goto error;
	}
	s->busy = dev;

	switch (insn->insn) {
	case INSN_BITS:
		ret = s->insn_bits(dev, s, insn, data);
		break;
	case INSN_CONFIG:
		/* XXX should check instruction length */
		ret = s->insn_config(dev, s, insn, data);
		break;
	default:
		ret = -EINVAL;
		break;
	}

	s->busy = NULL;
error:

	mutex_unlock(&dev->mutex);
	return ret;
}

int comedi_dio_get_config(struct comedi_device *dev, unsigned int subdev,
			  unsigned int chan, unsigned int *io)
{
	struct comedi_insn insn;
	unsigned int data[2];
	int ret;

	memset(&insn, 0, sizeof(insn));
	insn.insn = INSN_CONFIG;
	insn.n = 2;
	insn.subdev = subdev;
	insn.chanspec = CR_PACK(chan, 0, 0);
	data[0] = INSN_CONFIG_DIO_QUERY;
	data[1] = 0;
	ret = comedi_do_insn(dev, &insn, data);
	if (ret >= 0)
		*io = data[1];
	return ret;
}
EXPORT_SYMBOL_GPL(comedi_dio_get_config);

int comedi_dio_config(struct comedi_device *dev, unsigned int subdev,
		      unsigned int chan, unsigned int io)
{
	struct comedi_insn insn;

	memset(&insn, 0, sizeof(insn));
	insn.insn = INSN_CONFIG;
	insn.n = 1;
	insn.subdev = subdev;
	insn.chanspec = CR_PACK(chan, 0, 0);

	return comedi_do_insn(dev, &insn, &io);
}
EXPORT_SYMBOL_GPL(comedi_dio_config);

int comedi_dio_bitfield2(struct comedi_device *dev, unsigned int subdev,
			 unsigned int mask, unsigned int *bits,
			 unsigned int base_channel)
{
	struct comedi_insn insn;
	unsigned int data[2];
	unsigned int n_chan;
	unsigned int shift;
	int ret;

	base_channel = CR_CHAN(base_channel);
	n_chan = comedi_get_n_channels(dev, subdev);
	if (base_channel >= n_chan)
		return -EINVAL;

	memset(&insn, 0, sizeof(insn));
	insn.insn = INSN_BITS;
	insn.chanspec = base_channel;
	insn.n = 2;
	insn.subdev = subdev;

	data[0] = mask;
	data[1] = *bits;

	/*
	 * Most drivers ignore the base channel in insn->chanspec.
	 * Fix this here if the subdevice has <= 32 channels.
	 */
	if (n_chan <= 32) {
		shift = base_channel;
		if (shift) {
			insn.chanspec = 0;
			data[0] <<= shift;
			data[1] <<= shift;
		}
	} else {
		shift = 0;
	}

	ret = comedi_do_insn(dev, &insn, data);
	*bits = data[1] >> shift;
	return ret;
}
EXPORT_SYMBOL_GPL(comedi_dio_bitfield2);

int comedi_find_subdevice_by_type(struct comedi_device *dev, int type,
				  unsigned int subd)
{
	struct comedi_subdevice *s;
	int ret = -ENODEV;

	down_read(&dev->attach_lock);
	if (dev->attached)
		for (; subd < dev->n_subdevices; subd++) {
			s = &dev->subdevices[subd];
			if (s->type == type) {
				ret = subd;
				break;
			}
		}
	up_read(&dev->attach_lock);
	return ret;
}
EXPORT_SYMBOL_GPL(comedi_find_subdevice_by_type);

int comedi_get_n_channels(struct comedi_device *dev, unsigned int subdevice)
{
	int n;

	down_read(&dev->attach_lock);
	if (!dev->attached || subdevice >= dev->n_subdevices)
		n = 0;
	else
		n = dev->subdevices[subdevice].n_chan;
	up_read(&dev->attach_lock);

	return n;
}
EXPORT_SYMBOL_GPL(comedi_get_n_channels);

static int __init kcomedilib_module_init(void)
{
	return 0;
}

static void __exit kcomedilib_module_exit(void)
{
}

module_init(kcomedilib_module_init);
module_exit(kcomedilib_module_exit);