kcomedilib_main.c revision a1525758c848aedf590bba3a919321e2d80fcd6e 
1/*
2    kcomedilib/kcomedilib.c
3    a comedlib interface for kernel modules
4
5    COMEDI - Linux Control and Measurement Device Interface
6    Copyright (C) 1997-2000 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#define __NO_VERSION__
25#include <linux/module.h>
26
27#include <linux/errno.h>
28#include <linux/kernel.h>
29#include <linux/sched.h>
30#include <linux/fcntl.h>
31#include <linux/delay.h>
32#include <linux/ioport.h>
33#include <linux/mm.h>
34#include <linux/io.h>
35
36#include "../comedi.h"
37#include "../comedilib.h"
38#include "../comedidev.h"
39
40MODULE_AUTHOR("David Schleef <ds@schleef.org>");
41MODULE_DESCRIPTION("Comedi kernel library");
42MODULE_LICENSE("GPL");
43
44void *comedi_open(const char *filename)
45{
46	struct comedi_device_file_info *dev_file_info;
47	struct comedi_device *dev;
48	unsigned int minor;
49
50	if (strncmp(filename, "/dev/comedi", 11) != 0)
51		return NULL;
52
53	minor = simple_strtoul(filename + 11, NULL, 0);
54
55	if (minor >= COMEDI_NUM_BOARD_MINORS)
56		return NULL;
57
58	dev_file_info = comedi_get_device_file_info(minor);
59	if (dev_file_info == NULL)
60		return NULL;
61	dev = dev_file_info->device;
62
63	if (dev == NULL || !dev->attached)
64		return NULL;
65
66	if (!try_module_get(dev->driver->module))
67		return NULL;
68
69	return (void *)dev;
70}
71EXPORT_SYMBOL(comedi_open);
72
73int comedi_close(void *d)
74{
75	struct comedi_device *dev = (struct comedi_device *)d;
76
77	module_put(dev->driver->module);
78
79	return 0;
80}
81EXPORT_SYMBOL(comedi_close);
82
83/*
84 *	COMEDI_INSN
85 *	perform an instruction
86 */
87int comedi_do_insn(void *d, struct comedi_insn *insn)
88{
89	struct comedi_device *dev = (struct comedi_device *)d;
90	struct comedi_subdevice *s;
91	int ret = 0;
92
93	if (insn->insn & INSN_MASK_SPECIAL) {
94		switch (insn->insn) {
95		case INSN_GTOD:
96			{
97				struct timeval tv;
98
99				do_gettimeofday(&tv);
100				insn->data[0] = tv.tv_sec;
101				insn->data[1] = tv.tv_usec;
102				ret = 2;
103
104				break;
105			}
106		case INSN_WAIT:
107			/* XXX isn't the value supposed to be nanosecs? */
108			if (insn->n != 1 || insn->data[0] >= 100) {
109				ret = -EINVAL;
110				break;
111			}
112			udelay(insn->data[0]);
113			ret = 1;
114			break;
115		case INSN_INTTRIG:
116			if (insn->n != 1) {
117				ret = -EINVAL;
118				break;
119			}
120			if (insn->subdev >= dev->n_subdevices) {
121				printk("%d not usable subdevice\n",
122				       insn->subdev);
123				ret = -EINVAL;
124				break;
125			}
126			s = dev->subdevices + insn->subdev;
127			if (!s->async) {
128				printk("no async\n");
129				ret = -EINVAL;
130				break;
131			}
132			if (!s->async->inttrig) {
133				printk("no inttrig\n");
134				ret = -EAGAIN;
135				break;
136			}
137			ret = s->async->inttrig(dev, s, insn->data[0]);
138			if (ret >= 0)
139				ret = 1;
140			break;
141		default:
142			ret = -EINVAL;
143		}
144	} else {
145		/* a subdevice instruction */
146		if (insn->subdev >= dev->n_subdevices) {
147			ret = -EINVAL;
148			goto error;
149		}
150		s = dev->subdevices + insn->subdev;
151
152		if (s->type == COMEDI_SUBD_UNUSED) {
153			printk("%d not useable subdevice\n", insn->subdev);
154			ret = -EIO;
155			goto error;
156		}
157
158		/* XXX check lock */
159
160		ret = comedi_check_chanlist(s, 1, &insn->chanspec);
161		if (ret < 0) {
162			printk("bad chanspec\n");
163			ret = -EINVAL;
164			goto error;
165		}
166
167		if (s->busy) {
168			ret = -EBUSY;
169			goto error;
170		}
171		s->busy = d;
172
173		switch (insn->insn) {
174		case INSN_READ:
175			ret = s->insn_read(dev, s, insn, insn->data);
176			break;
177		case INSN_WRITE:
178			ret = s->insn_write(dev, s, insn, insn->data);
179			break;
180		case INSN_BITS:
181			ret = s->insn_bits(dev, s, insn, insn->data);
182			break;
183		case INSN_CONFIG:
184			/* XXX should check instruction length */
185			ret = s->insn_config(dev, s, insn, insn->data);
186			break;
187		default:
188			ret = -EINVAL;
189			break;
190		}
191
192		s->busy = NULL;
193	}
194	if (ret < 0)
195		goto error;
196#if 0
197	/* XXX do we want this? -- abbotti #if'ed it out for now. */
198	if (ret != insn->n) {
199		printk("BUG: result of insn != insn.n\n");
200		ret = -EINVAL;
201		goto error;
202	}
203#endif
204error:
205
206	return ret;
207}
208
209int comedi_dio_config(void *dev, unsigned int subdev, unsigned int chan,
210		      unsigned int io)
211{
212	struct comedi_insn insn;
213
214	memset(&insn, 0, sizeof(insn));
215	insn.insn = INSN_CONFIG;
216	insn.n = 1;
217	insn.data = &io;
218	insn.subdev = subdev;
219	insn.chanspec = CR_PACK(chan, 0, 0);
220
221	return comedi_do_insn(dev, &insn);
222}
223EXPORT_SYMBOL(comedi_dio_config);
224
225int comedi_dio_bitfield(void *dev, unsigned int subdev, unsigned int mask,
226			unsigned int *bits)
227{
228	struct comedi_insn insn;
229	unsigned int data[2];
230	int ret;
231
232	memset(&insn, 0, sizeof(insn));
233	insn.insn = INSN_BITS;
234	insn.n = 2;
235	insn.data = data;
236	insn.subdev = subdev;
237
238	data[0] = mask;
239	data[1] = *bits;
240
241	ret = comedi_do_insn(dev, &insn);
242
243	*bits = data[1];
244
245	return ret;
246}
247EXPORT_SYMBOL(comedi_dio_bitfield);
248
249int comedi_find_subdevice_by_type(void *d, int type, unsigned int subd)
250{
251	struct comedi_device *dev = (struct comedi_device *)d;
252
253	if (subd > dev->n_subdevices)
254		return -ENODEV;
255
256	for (; subd < dev->n_subdevices; subd++) {
257		if (dev->subdevices[subd].type == type)
258			return subd;
259	}
260	return -1;
261}
262EXPORT_SYMBOL(comedi_find_subdevice_by_type);
263
264int comedi_get_n_channels(void *d, unsigned int subdevice)
265{
266	struct comedi_device *dev = (struct comedi_device *)d;
267	struct comedi_subdevice *s = dev->subdevices + subdevice;
268
269	return s->n_chan;
270}
271EXPORT_SYMBOL(comedi_get_n_channels);
272