1 // SPDX-License-Identifier: GPL-2.0+
3 * kcomedilib/kcomedilib.c
4 * a comedlib interface for kernel modules
6 * COMEDI - Linux Control and Measurement Device Interface
7 * Copyright (C) 1997-2000 David A. Schleef <ds@schleef.org>
10 #include <linux/module.h>
12 #include <linux/errno.h>
13 #include <linux/kernel.h>
14 #include <linux/sched.h>
15 #include <linux/fcntl.h>
19 #include <linux/comedi.h>
20 #include <linux/comedi/comedidev.h>
21 #include <linux/comedi/comedilib.h>
23 MODULE_AUTHOR("David Schleef <ds@schleef.org>");
24 MODULE_DESCRIPTION("Comedi kernel library");
25 MODULE_LICENSE("GPL");
27 struct comedi_device *comedi_open(const char *filename)
29 struct comedi_device *dev, *retval = NULL;
32 if (strncmp(filename, "/dev/comedi", 11) != 0)
35 if (kstrtouint(filename + 11, 0, &minor))
38 if (minor >= COMEDI_NUM_BOARD_MINORS)
41 dev = comedi_dev_get_from_minor(minor);
45 down_read(&dev->attach_lock);
50 up_read(&dev->attach_lock);
57 EXPORT_SYMBOL_GPL(comedi_open);
59 int comedi_close(struct comedi_device *dev)
64 EXPORT_SYMBOL_GPL(comedi_close);
66 static int comedi_do_insn(struct comedi_device *dev,
67 struct comedi_insn *insn,
70 struct comedi_subdevice *s;
73 mutex_lock(&dev->mutex);
80 /* a subdevice instruction */
81 if (insn->subdev >= dev->n_subdevices) {
85 s = &dev->subdevices[insn->subdev];
87 if (s->type == COMEDI_SUBD_UNUSED) {
88 dev_err(dev->class_dev,
89 "%d not usable subdevice\n", insn->subdev);
96 ret = comedi_check_chanlist(s, 1, &insn->chanspec);
98 dev_err(dev->class_dev, "bad chanspec\n");
109 switch (insn->insn) {
111 ret = s->insn_bits(dev, s, insn, data);
114 /* XXX should check instruction length */
115 ret = s->insn_config(dev, s, insn, data);
125 mutex_unlock(&dev->mutex);
129 int comedi_dio_get_config(struct comedi_device *dev, unsigned int subdev,
130 unsigned int chan, unsigned int *io)
132 struct comedi_insn insn;
133 unsigned int data[2];
136 memset(&insn, 0, sizeof(insn));
137 insn.insn = INSN_CONFIG;
139 insn.subdev = subdev;
140 insn.chanspec = CR_PACK(chan, 0, 0);
141 data[0] = INSN_CONFIG_DIO_QUERY;
143 ret = comedi_do_insn(dev, &insn, data);
148 EXPORT_SYMBOL_GPL(comedi_dio_get_config);
150 int comedi_dio_config(struct comedi_device *dev, unsigned int subdev,
151 unsigned int chan, unsigned int io)
153 struct comedi_insn insn;
155 memset(&insn, 0, sizeof(insn));
156 insn.insn = INSN_CONFIG;
158 insn.subdev = subdev;
159 insn.chanspec = CR_PACK(chan, 0, 0);
161 return comedi_do_insn(dev, &insn, &io);
163 EXPORT_SYMBOL_GPL(comedi_dio_config);
165 int comedi_dio_bitfield2(struct comedi_device *dev, unsigned int subdev,
166 unsigned int mask, unsigned int *bits,
167 unsigned int base_channel)
169 struct comedi_insn insn;
170 unsigned int data[2];
175 base_channel = CR_CHAN(base_channel);
176 n_chan = comedi_get_n_channels(dev, subdev);
177 if (base_channel >= n_chan)
180 memset(&insn, 0, sizeof(insn));
181 insn.insn = INSN_BITS;
182 insn.chanspec = base_channel;
184 insn.subdev = subdev;
190 * Most drivers ignore the base channel in insn->chanspec.
191 * Fix this here if the subdevice has <= 32 channels.
194 shift = base_channel;
204 ret = comedi_do_insn(dev, &insn, data);
205 *bits = data[1] >> shift;
208 EXPORT_SYMBOL_GPL(comedi_dio_bitfield2);
210 int comedi_find_subdevice_by_type(struct comedi_device *dev, int type,
213 struct comedi_subdevice *s;
216 down_read(&dev->attach_lock);
218 for (; subd < dev->n_subdevices; subd++) {
219 s = &dev->subdevices[subd];
220 if (s->type == type) {
225 up_read(&dev->attach_lock);
228 EXPORT_SYMBOL_GPL(comedi_find_subdevice_by_type);
230 int comedi_get_n_channels(struct comedi_device *dev, unsigned int subdevice)
234 down_read(&dev->attach_lock);
235 if (!dev->attached || subdevice >= dev->n_subdevices)
238 n = dev->subdevices[subdevice].n_chan;
239 up_read(&dev->attach_lock);
243 EXPORT_SYMBOL_GPL(comedi_get_n_channels);
245 static int __init kcomedilib_module_init(void)
250 static void __exit kcomedilib_module_exit(void)
254 module_init(kcomedilib_module_init);
255 module_exit(kcomedilib_module_exit);