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
19 #include <linux/module.h>
20
21 #include <linux/errno.h>
22 #include <linux/kernel.h>
23 #include <linux/sched.h>
24 #include <linux/fcntl.h>
25 #include <linux/mm.h>
26 #include <linux/io.h>
27
28 #include "../comedi.h"
29 #include "../comedilib.h"
30 #include "../comedidev.h"
31
32 MODULE_AUTHOR("David Schleef <ds@schleef.org>");
33 MODULE_DESCRIPTION("Comedi kernel library");
34 MODULE_LICENSE("GPL");
35
comedi_open(const char * filename)36 struct comedi_device *comedi_open(const char *filename)
37 {
38 struct comedi_device *dev, *retval = NULL;
39 unsigned int minor;
40
41 if (strncmp(filename, "/dev/comedi", 11) != 0)
42 return NULL;
43
44 if (kstrtouint(filename + 11, 0, &minor))
45 return NULL;
46
47 if (minor >= COMEDI_NUM_BOARD_MINORS)
48 return NULL;
49
50 dev = comedi_dev_get_from_minor(minor);
51 if (!dev)
52 return NULL;
53
54 down_read(&dev->attach_lock);
55 if (dev->attached)
56 retval = dev;
57 else
58 retval = NULL;
59 up_read(&dev->attach_lock);
60
61 if (!retval)
62 comedi_dev_put(dev);
63
64 return retval;
65 }
66 EXPORT_SYMBOL_GPL(comedi_open);
67
comedi_close(struct comedi_device * dev)68 int comedi_close(struct comedi_device *dev)
69 {
70 comedi_dev_put(dev);
71 return 0;
72 }
73 EXPORT_SYMBOL_GPL(comedi_close);
74
comedi_do_insn(struct comedi_device * dev,struct comedi_insn * insn,unsigned int * data)75 static int comedi_do_insn(struct comedi_device *dev,
76 struct comedi_insn *insn,
77 unsigned int *data)
78 {
79 struct comedi_subdevice *s;
80 int ret;
81
82 mutex_lock(&dev->mutex);
83
84 if (!dev->attached) {
85 ret = -EINVAL;
86 goto error;
87 }
88
89 /* a subdevice instruction */
90 if (insn->subdev >= dev->n_subdevices) {
91 ret = -EINVAL;
92 goto error;
93 }
94 s = &dev->subdevices[insn->subdev];
95
96 if (s->type == COMEDI_SUBD_UNUSED) {
97 dev_err(dev->class_dev,
98 "%d not usable subdevice\n", insn->subdev);
99 ret = -EIO;
100 goto error;
101 }
102
103 /* XXX check lock */
104
105 ret = comedi_check_chanlist(s, 1, &insn->chanspec);
106 if (ret < 0) {
107 dev_err(dev->class_dev, "bad chanspec\n");
108 ret = -EINVAL;
109 goto error;
110 }
111
112 if (s->busy) {
113 ret = -EBUSY;
114 goto error;
115 }
116 s->busy = dev;
117
118 switch (insn->insn) {
119 case INSN_BITS:
120 ret = s->insn_bits(dev, s, insn, data);
121 break;
122 case INSN_CONFIG:
123 /* XXX should check instruction length */
124 ret = s->insn_config(dev, s, insn, data);
125 break;
126 default:
127 ret = -EINVAL;
128 break;
129 }
130
131 s->busy = NULL;
132 error:
133
134 mutex_unlock(&dev->mutex);
135 return ret;
136 }
137
comedi_dio_get_config(struct comedi_device * dev,unsigned int subdev,unsigned int chan,unsigned int * io)138 int comedi_dio_get_config(struct comedi_device *dev, unsigned int subdev,
139 unsigned int chan, unsigned int *io)
140 {
141 struct comedi_insn insn;
142 unsigned int data[2];
143 int ret;
144
145 memset(&insn, 0, sizeof(insn));
146 insn.insn = INSN_CONFIG;
147 insn.n = 2;
148 insn.subdev = subdev;
149 insn.chanspec = CR_PACK(chan, 0, 0);
150 data[0] = INSN_CONFIG_DIO_QUERY;
151 data[1] = 0;
152 ret = comedi_do_insn(dev, &insn, data);
153 if (ret >= 0)
154 *io = data[1];
155 return ret;
156 }
157 EXPORT_SYMBOL_GPL(comedi_dio_get_config);
158
comedi_dio_config(struct comedi_device * dev,unsigned int subdev,unsigned int chan,unsigned int io)159 int comedi_dio_config(struct comedi_device *dev, unsigned int subdev,
160 unsigned int chan, unsigned int io)
161 {
162 struct comedi_insn insn;
163
164 memset(&insn, 0, sizeof(insn));
165 insn.insn = INSN_CONFIG;
166 insn.n = 1;
167 insn.subdev = subdev;
168 insn.chanspec = CR_PACK(chan, 0, 0);
169
170 return comedi_do_insn(dev, &insn, &io);
171 }
172 EXPORT_SYMBOL_GPL(comedi_dio_config);
173
comedi_dio_bitfield2(struct comedi_device * dev,unsigned int subdev,unsigned int mask,unsigned int * bits,unsigned int base_channel)174 int comedi_dio_bitfield2(struct comedi_device *dev, unsigned int subdev,
175 unsigned int mask, unsigned int *bits,
176 unsigned int base_channel)
177 {
178 struct comedi_insn insn;
179 unsigned int data[2];
180 unsigned int n_chan;
181 unsigned int shift;
182 int ret;
183
184 base_channel = CR_CHAN(base_channel);
185 n_chan = comedi_get_n_channels(dev, subdev);
186 if (base_channel >= n_chan)
187 return -EINVAL;
188
189 memset(&insn, 0, sizeof(insn));
190 insn.insn = INSN_BITS;
191 insn.chanspec = base_channel;
192 insn.n = 2;
193 insn.subdev = subdev;
194
195 data[0] = mask;
196 data[1] = *bits;
197
198 /*
199 * Most drivers ignore the base channel in insn->chanspec.
200 * Fix this here if the subdevice has <= 32 channels.
201 */
202 if (n_chan <= 32) {
203 shift = base_channel;
204 if (shift) {
205 insn.chanspec = 0;
206 data[0] <<= shift;
207 data[1] <<= shift;
208 }
209 } else {
210 shift = 0;
211 }
212
213 ret = comedi_do_insn(dev, &insn, data);
214 *bits = data[1] >> shift;
215 return ret;
216 }
217 EXPORT_SYMBOL_GPL(comedi_dio_bitfield2);
218
comedi_find_subdevice_by_type(struct comedi_device * dev,int type,unsigned int subd)219 int comedi_find_subdevice_by_type(struct comedi_device *dev, int type,
220 unsigned int subd)
221 {
222 struct comedi_subdevice *s;
223 int ret = -ENODEV;
224
225 down_read(&dev->attach_lock);
226 if (dev->attached)
227 for (; subd < dev->n_subdevices; subd++) {
228 s = &dev->subdevices[subd];
229 if (s->type == type) {
230 ret = subd;
231 break;
232 }
233 }
234 up_read(&dev->attach_lock);
235 return ret;
236 }
237 EXPORT_SYMBOL_GPL(comedi_find_subdevice_by_type);
238
comedi_get_n_channels(struct comedi_device * dev,unsigned int subdevice)239 int comedi_get_n_channels(struct comedi_device *dev, unsigned int subdevice)
240 {
241 int n;
242
243 down_read(&dev->attach_lock);
244 if (!dev->attached || subdevice >= dev->n_subdevices)
245 n = 0;
246 else
247 n = dev->subdevices[subdevice].n_chan;
248 up_read(&dev->attach_lock);
249
250 return n;
251 }
252 EXPORT_SYMBOL_GPL(comedi_get_n_channels);
253