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
40 MODULE_AUTHOR("David Schleef <ds@schleef.org>");
41 MODULE_DESCRIPTION("Comedi kernel library");
42 MODULE_LICENSE("GPL");
43
comedi_open(const char * filename)44 struct comedi_device *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 dev;
70 }
71 EXPORT_SYMBOL(comedi_open);
72
comedi_close(struct comedi_device * d)73 int comedi_close(struct comedi_device *d)
74 {
75 struct comedi_device *dev = (struct comedi_device *)d;
76
77 module_put(dev->driver->module);
78
79 return 0;
80 }
81 EXPORT_SYMBOL(comedi_close);
82
comedi_do_insn(struct comedi_device * dev,struct comedi_insn * insn)83 static int comedi_do_insn(struct comedi_device *dev, struct comedi_insn *insn)
84 {
85 struct comedi_subdevice *s;
86 int ret = 0;
87
88 /* a subdevice instruction */
89 if (insn->subdev >= dev->n_subdevices) {
90 ret = -EINVAL;
91 goto error;
92 }
93 s = dev->subdevices + insn->subdev;
94
95 if (s->type == COMEDI_SUBD_UNUSED) {
96 printk(KERN_ERR "%d not useable subdevice\n", insn->subdev);
97 ret = -EIO;
98 goto error;
99 }
100
101 /* XXX check lock */
102
103 ret = comedi_check_chanlist(s, 1, &insn->chanspec);
104 if (ret < 0) {
105 printk(KERN_ERR "bad chanspec\n");
106 ret = -EINVAL;
107 goto error;
108 }
109
110 if (s->busy) {
111 ret = -EBUSY;
112 goto error;
113 }
114 s->busy = dev;
115
116 switch (insn->insn) {
117 case INSN_BITS:
118 ret = s->insn_bits(dev, s, insn, insn->data);
119 break;
120 case INSN_CONFIG:
121 /* XXX should check instruction length */
122 ret = s->insn_config(dev, s, insn, insn->data);
123 break;
124 default:
125 ret = -EINVAL;
126 break;
127 }
128
129 s->busy = NULL;
130 error:
131
132 return ret;
133 }
134
comedi_dio_config(struct comedi_device * dev,unsigned int subdev,unsigned int chan,unsigned int io)135 int comedi_dio_config(struct comedi_device *dev, unsigned int subdev,
136 unsigned int chan, unsigned int io)
137 {
138 struct comedi_insn insn;
139
140 memset(&insn, 0, sizeof(insn));
141 insn.insn = INSN_CONFIG;
142 insn.n = 1;
143 insn.data = &io;
144 insn.subdev = subdev;
145 insn.chanspec = CR_PACK(chan, 0, 0);
146
147 return comedi_do_insn(dev, &insn);
148 }
149 EXPORT_SYMBOL(comedi_dio_config);
150
comedi_dio_bitfield(struct comedi_device * dev,unsigned int subdev,unsigned int mask,unsigned int * bits)151 int comedi_dio_bitfield(struct comedi_device *dev, unsigned int subdev,
152 unsigned int mask, unsigned int *bits)
153 {
154 struct comedi_insn insn;
155 unsigned int data[2];
156 int ret;
157
158 memset(&insn, 0, sizeof(insn));
159 insn.insn = INSN_BITS;
160 insn.n = 2;
161 insn.data = data;
162 insn.subdev = subdev;
163
164 data[0] = mask;
165 data[1] = *bits;
166
167 ret = comedi_do_insn(dev, &insn);
168
169 *bits = data[1];
170
171 return ret;
172 }
173 EXPORT_SYMBOL(comedi_dio_bitfield);
174
comedi_find_subdevice_by_type(struct comedi_device * dev,int type,unsigned int subd)175 int comedi_find_subdevice_by_type(struct comedi_device *dev, int type,
176 unsigned int subd)
177 {
178 if (subd > dev->n_subdevices)
179 return -ENODEV;
180
181 for (; subd < dev->n_subdevices; subd++) {
182 if (dev->subdevices[subd].type == type)
183 return subd;
184 }
185 return -1;
186 }
187 EXPORT_SYMBOL(comedi_find_subdevice_by_type);
188
comedi_get_n_channels(struct comedi_device * dev,unsigned int subdevice)189 int comedi_get_n_channels(struct comedi_device *dev, unsigned int subdevice)
190 {
191 struct comedi_subdevice *s = dev->subdevices + subdevice;
192
193 return s->n_chan;
194 }
195 EXPORT_SYMBOL(comedi_get_n_channels);
196