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// 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 "../comedi.h"
#include "../comedilib.h"
#include "../comedidev.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);
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