- 根目录:
- drivers
- staging
- comedi
- comedi_fops.c
/*
comedi/comedi_fops.c
comedi kernel module
COMEDI - Linux Control and Measurement Device Interface
Copyright (C) 1997-2000 David A. Schleef <ds@schleef.org>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#undef DEBUG
#define __NO_VERSION__
#include "comedi_fops.h"
#include "comedi_compat32.h"
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/fcntl.h>
#include <linux/delay.h>
#include <linux/ioport.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/kmod.h>
#include <linux/poll.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/vmalloc.h>
#include <linux/fs.h>
#include "comedidev.h"
#include <linux/cdev.h>
#include <linux/stat.h>
#include <linux/io.h>
#include <linux/uaccess.h>
#include "internal.h"
MODULE_AUTHOR("http://www.comedi.org");
MODULE_DESCRIPTION("Comedi core module");
MODULE_LICENSE("GPL");
#ifdef CONFIG_COMEDI_DEBUG
int comedi_debug;
EXPORT_SYMBOL(comedi_debug);
module_param(comedi_debug, int, 0644);
#endif
bool comedi_autoconfig = 1;
module_param(comedi_autoconfig, bool, 0444);
static int comedi_num_legacy_minors;
module_param(comedi_num_legacy_minors, int, 0444);
static DEFINE_SPINLOCK(comedi_file_info_table_lock);
static struct comedi_device_file_info
*comedi_file_info_table[COMEDI_NUM_MINORS];
static int do_devconfig_ioctl(struct comedi_device *dev,
struct comedi_devconfig __user *arg);
static int do_bufconfig_ioctl(struct comedi_device *dev,
struct comedi_bufconfig __user *arg);
static int do_devinfo_ioctl(struct comedi_device *dev,
struct comedi_devinfo __user *arg,
struct file *file);
static int do_subdinfo_ioctl(struct comedi_device *dev,
struct comedi_subdinfo __user *arg, void *file);
static int do_chaninfo_ioctl(struct comedi_device *dev,
struct comedi_chaninfo __user *arg);
static int do_bufinfo_ioctl(struct comedi_device *dev,
struct comedi_bufinfo __user *arg, void *file);
static int do_cmd_ioctl(struct comedi_device *dev,
struct comedi_cmd __user *arg, void *file);
static int do_lock_ioctl(struct comedi_device *dev, unsigned int arg,
void *file);
static int do_unlock_ioctl(struct comedi_device *dev, unsigned int arg,
void *file);
static int do_cancel_ioctl(struct comedi_device *dev, unsigned int arg,
void *file);
static int do_cmdtest_ioctl(struct comedi_device *dev,
struct comedi_cmd __user *arg, void *file);
static int do_insnlist_ioctl(struct comedi_device *dev,
struct comedi_insnlist __user *arg, void *file);
static int do_insn_ioctl(struct comedi_device *dev,
struct comedi_insn __user *arg, void *file);
static int do_poll_ioctl(struct comedi_device *dev, unsigned int subd,
void *file);
static void do_become_nonbusy(struct comedi_device *dev,
struct comedi_subdevice *s);
static int do_cancel(struct comedi_device *dev, struct comedi_subdevice *s);
static int comedi_fasync(int fd, struct file *file, int on);
static int is_device_busy(struct comedi_device *dev);
static int resize_async_buffer(struct comedi_device *dev,
struct comedi_subdevice *s,
struct comedi_async *async, unsigned new_size);
/* declarations for sysfs attribute files */
static struct device_attribute dev_attr_max_read_buffer_kb;
static struct device_attribute dev_attr_read_buffer_kb;
static struct device_attribute dev_attr_max_write_buffer_kb;
static struct device_attribute dev_attr_write_buffer_kb;
static long comedi_unlocked_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
const unsigned minor = iminor(file->f_dentry->d_inode);
struct comedi_device_file_info *dev_file_info =
comedi_get_device_file_info(minor);
struct comedi_device *dev;
int rc;
if (dev_file_info == NULL || dev_file_info->device == NULL)
return -ENODEV;
dev = dev_file_info->device;
mutex_lock(&dev->mutex);
/* Device config is special, because it must work on
* an unconfigured device. */
if (cmd == COMEDI_DEVCONFIG) {
if (minor >= COMEDI_NUM_BOARD_MINORS) {
/* Device config not appropriate on non-board minors. */
rc = -ENOTTY;
goto done;
}
rc = do_devconfig_ioctl(dev,
(struct comedi_devconfig __user *)arg);
if (rc == 0)
/* Evade comedi_auto_unconfig(). */
dev_file_info->hardware_device = NULL;
goto done;
}
if (!dev->attached) {
DPRINTK("no driver configured on /dev/comedi%i\n", dev->minor);
rc = -ENODEV;
goto done;
}
switch (cmd) {
case COMEDI_BUFCONFIG:
rc = do_bufconfig_ioctl(dev,
(struct comedi_bufconfig __user *)arg);
break;
case COMEDI_DEVINFO:
rc = do_devinfo_ioctl(dev, (struct comedi_devinfo __user *)arg,
file);
break;
case COMEDI_SUBDINFO:
rc = do_subdinfo_ioctl(dev,
(struct comedi_subdinfo __user *)arg,
file);
break;
case COMEDI_CHANINFO:
rc = do_chaninfo_ioctl(dev, (void __user *)arg);
break;
case COMEDI_RANGEINFO:
rc = do_rangeinfo_ioctl(dev, (void __user *)arg);
break;
case COMEDI_BUFINFO:
rc = do_bufinfo_ioctl(dev,
(struct comedi_bufinfo __user *)arg,
file);
break;
case COMEDI_LOCK:
rc = do_lock_ioctl(dev, arg, file);
break;
case COMEDI_UNLOCK:
rc = do_unlock_ioctl(dev, arg, file);
break;
case COMEDI_CANCEL:
rc = do_cancel_ioctl(dev, arg, file);
break;
case COMEDI_CMD:
rc = do_cmd_ioctl(dev, (struct comedi_cmd __user *)arg, file);
break;
case COMEDI_CMDTEST:
rc = do_cmdtest_ioctl(dev, (struct comedi_cmd __user *)arg,
file);
break;
case COMEDI_INSNLIST:
rc = do_insnlist_ioctl(dev,
(struct comedi_insnlist __user *)arg,
file);
break;
case COMEDI_INSN:
rc = do_insn_ioctl(dev, (struct comedi_insn __user *)arg,
file);
break;
case COMEDI_POLL:
rc = do_poll_ioctl(dev, arg, file);
break;
default:
rc = -ENOTTY;
break;
}
done:
mutex_unlock(&dev->mutex);
return rc;
}
/*
COMEDI_DEVCONFIG
device config ioctl
arg:
pointer to devconfig structure
reads:
devconfig structure at arg
writes:
none
*/
static int do_devconfig_ioctl(struct comedi_device *dev,
struct comedi_devconfig __user *arg)
{
struct comedi_devconfig it;
int ret;
unsigned char *aux_data = NULL;
int aux_len;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
if (arg == NULL) {
if (is_device_busy(dev))
return -EBUSY;
if (dev->attached) {
struct module *driver_module = dev->driver->module;
comedi_device_detach(dev);
module_put(driver_module);
}
return 0;
}
if (copy_from_user(&it, arg, sizeof(struct comedi_devconfig)))
return -EFAULT;
it.board_name[COMEDI_NAMELEN - 1] = 0;
if (comedi_aux_data(it.options, 0) &&
it.options[COMEDI_DEVCONF_AUX_DATA_LENGTH]) {
int bit_shift;
aux_len = it.options[COMEDI_DEVCONF_AUX_DATA_LENGTH];
if (aux_len < 0)
return -EFAULT;
aux_data = vmalloc(aux_len);
if (!aux_data)
return -ENOMEM;
if (copy_from_user(aux_data,
comedi_aux_data(it.options, 0), aux_len)) {
vfree(aux_data);
return -EFAULT;
}
it.options[COMEDI_DEVCONF_AUX_DATA_LO] =
(unsigned long)aux_data;
if (sizeof(void *) > sizeof(int)) {
bit_shift = sizeof(int) * 8;
it.options[COMEDI_DEVCONF_AUX_DATA_HI] =
((unsigned long)aux_data) >> bit_shift;
} else
it.options[COMEDI_DEVCONF_AUX_DATA_HI] = 0;
}
ret = comedi_device_attach(dev, &it);
if (ret == 0) {
if (!try_module_get(dev->driver->module)) {
comedi_device_detach(dev);
ret = -ENOSYS;
}
}
if (aux_data)
vfree(aux_data);
return ret;
}
/*
COMEDI_BUFCONFIG
buffer configuration ioctl
arg:
pointer to bufconfig structure
reads:
bufconfig at arg
writes:
modified bufconfig at arg
*/
static int do_bufconfig_ioctl(struct comedi_device *dev,
struct comedi_bufconfig __user *arg)
{
struct comedi_bufconfig bc;
struct comedi_async *async;
struct comedi_subdevice *s;
int retval = 0;
if (copy_from_user(&bc, arg, sizeof(struct comedi_bufconfig)))
return -EFAULT;
if (bc.subdevice >= dev->n_subdevices || bc.subdevice < 0)
return -EINVAL;
s = dev->subdevices + bc.subdevice;
async = s->async;
if (!async) {
DPRINTK("subdevice does not have async capability\n");
bc.size = 0;
bc.maximum_size = 0;
goto copyback;
}
if (bc.maximum_size) {
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
async->max_bufsize = bc.maximum_size;
}
if (bc.size) {
retval = resize_async_buffer(dev, s, async, bc.size);
if (retval < 0)
return retval;
}
bc.size = async->prealloc_bufsz;
bc.maximum_size = async->max_bufsize;
copyback:
if (copy_to_user(arg, &bc, sizeof(struct comedi_bufconfig)))
return -EFAULT;
return 0;
}
/*
COMEDI_DEVINFO
device info ioctl
arg:
pointer to devinfo structure
reads:
none
writes:
devinfo structure
*/
static int do_devinfo_ioctl(struct comedi_device *dev,
struct comedi_devinfo __user *arg,
struct file *file)
{
struct comedi_devinfo devinfo;
const unsigned minor = iminor(file->f_dentry->d_inode);
struct comedi_device_file_info *dev_file_info =
comedi_get_device_file_info(minor);
struct comedi_subdevice *read_subdev =
comedi_get_read_subdevice(dev_file_info);
struct comedi_subdevice *write_subdev =
comedi_get_write_subdevice(dev_file_info);
memset(&devinfo, 0, sizeof(devinfo));
/* fill devinfo structure */
devinfo.version_code = COMEDI_VERSION_CODE;
devinfo.n_subdevs = dev->n_subdevices;
strlcpy(devinfo.driver_name, dev->driver->driver_name, COMEDI_NAMELEN);
strlcpy(devinfo.board_name, dev->board_name, COMEDI_NAMELEN);
if (read_subdev)
devinfo.read_subdevice = read_subdev - dev->subdevices;
else
devinfo.read_subdevice = -1;
if (write_subdev)
devinfo.write_subdevice = write_subdev - dev->subdevices;
else
devinfo.write_subdevice = -1;
if (copy_to_user(arg, &devinfo, sizeof(struct comedi_devinfo)))
return -EFAULT;
return 0;
}
/*
COMEDI_SUBDINFO
subdevice info ioctl
arg:
pointer to array of subdevice info structures
reads:
none
writes:
array of subdevice info structures at arg
*/
static int do_subdinfo_ioctl(struct comedi_device *dev,
struct comedi_subdinfo __user *arg, void *file)
{
int ret, i;
struct comedi_subdinfo *tmp, *us;
struct comedi_subdevice *s;
tmp =
kcalloc(dev->n_subdevices, sizeof(struct comedi_subdinfo),
GFP_KERNEL);
if (!tmp)
return -ENOMEM;
/* fill subdinfo structs */
for (i = 0; i < dev->n_subdevices; i++) {
s = dev->subdevices + i;
us = tmp + i;
us->type = s->type;
us->n_chan = s->n_chan;
us->subd_flags = s->subdev_flags;
if (comedi_get_subdevice_runflags(s) & SRF_RUNNING)
us->subd_flags |= SDF_RUNNING;
#define TIMER_nanosec 5 /* backwards compatibility */
us->timer_type = TIMER_nanosec;
us->len_chanlist = s->len_chanlist;
us->maxdata = s->maxdata;
if (s->range_table) {
us->range_type =
(i << 24) | (0 << 16) | (s->range_table->length);
} else {
us->range_type = 0; /* XXX */
}
us->flags = s->flags;
if (s->busy)
us->subd_flags |= SDF_BUSY;
if (s->busy == file)
us->subd_flags |= SDF_BUSY_OWNER;
if (s->lock)
us->subd_flags |= SDF_LOCKED;
if (s->lock == file)
us->subd_flags |= SDF_LOCK_OWNER;
if (!s->maxdata && s->maxdata_list)
us->subd_flags |= SDF_MAXDATA;
if (s->flaglist)
us->subd_flags |= SDF_FLAGS;
if (s->range_table_list)
us->subd_flags |= SDF_RANGETYPE;
if (s->do_cmd)
us->subd_flags |= SDF_CMD;
if (s->insn_bits != &insn_inval)
us->insn_bits_support = COMEDI_SUPPORTED;
else
us->insn_bits_support = COMEDI_UNSUPPORTED;
us->settling_time_0 = s->settling_time_0;
}
ret = copy_to_user(arg, tmp,
dev->n_subdevices * sizeof(struct comedi_subdinfo));
kfree(tmp);
return ret ? -EFAULT : 0;
}
/*
COMEDI_CHANINFO
subdevice info ioctl
arg:
pointer to chaninfo structure
reads:
chaninfo structure at arg
writes:
arrays at elements of chaninfo structure
*/
static int do_chaninfo_ioctl(struct comedi_device *dev,
struct comedi_chaninfo __user *arg)
{
struct comedi_subdevice *s;
struct comedi_chaninfo it;
if (copy_from_user(&it, arg, sizeof(struct comedi_chaninfo)))
return -EFAULT;
if (it.subdev >= dev->n_subdevices)
return -EINVAL;
s = dev->subdevices + it.subdev;
if (it.maxdata_list) {
if (s->maxdata || !s->maxdata_list)
return -EINVAL;
if (copy_to_user(it.maxdata_list, s->maxdata_list,
s->n_chan * sizeof(unsigned int)))
return -EFAULT;
}
if (it.flaglist) {
if (!s->flaglist)
return -EINVAL;
if (copy_to_user(it.flaglist, s->flaglist,
s->n_chan * sizeof(unsigned int)))
return -EFAULT;
}
if (it.rangelist) {
int i;
if (!s->range_table_list)
return -EINVAL;
for (i = 0; i < s->n_chan; i++) {
int x;
x = (dev->minor << 28) | (it.subdev << 24) | (i << 16) |
(s->range_table_list[i]->length);
if (put_user(x, it.rangelist + i))
return -EFAULT;
}
#if 0
if (copy_to_user(it.rangelist, s->range_type_list,
s->n_chan * sizeof(unsigned int)))
return -EFAULT;
#endif
}
return 0;
}
/*
COMEDI_BUFINFO
buffer information ioctl
arg:
pointer to bufinfo structure
reads:
bufinfo at arg
writes:
modified bufinfo at arg
*/
static int do_bufinfo_ioctl(struct comedi_device *dev,
struct comedi_bufinfo __user *arg, void *file)
{
struct comedi_bufinfo bi;
struct comedi_subdevice *s;
struct comedi_async *async;
if (copy_from_user(&bi, arg, sizeof(struct comedi_bufinfo)))
return -EFAULT;
if (bi.subdevice >= dev->n_subdevices || bi.subdevice < 0)
return -EINVAL;
s = dev->subdevices + bi.subdevice;
if (s->lock && s->lock != file)
return -EACCES;
async = s->async;
if (!async) {
DPRINTK("subdevice does not have async capability\n");
bi.buf_write_ptr = 0;
bi.buf_read_ptr = 0;
bi.buf_write_count = 0;
bi.buf_read_count = 0;
bi.bytes_read = 0;
bi.bytes_written = 0;
goto copyback;
}
if (!s->busy) {
bi.bytes_read = 0;
bi.bytes_written = 0;
goto copyback_position;
}
if (s->busy != file)
return -EACCES;
if (bi.bytes_read && (s->subdev_flags & SDF_CMD_READ)) {
bi.bytes_read = comedi_buf_read_alloc(async, bi.bytes_read);
comedi_buf_read_free(async, bi.bytes_read);
if (!(comedi_get_subdevice_runflags(s) & (SRF_ERROR |
SRF_RUNNING))
&& async->buf_write_count == async->buf_read_count) {
do_become_nonbusy(dev, s);
}
}
if (bi.bytes_written && (s->subdev_flags & SDF_CMD_WRITE)) {
bi.bytes_written =
comedi_buf_write_alloc(async, bi.bytes_written);
comedi_buf_write_free(async, bi.bytes_written);
}
copyback_position:
bi.buf_write_count = async->buf_write_count;
bi.buf_write_ptr = async->buf_write_ptr;
bi.buf_read_count = async->buf_read_count;
bi.buf_read_ptr = async->buf_read_ptr;
copyback:
if (copy_to_user(arg, &bi, sizeof(struct comedi_bufinfo)))
return -EFAULT;
return 0;
}
static int parse_insn(struct comedi_device *dev, struct comedi_insn *insn,
unsigned int *data, void *file);
/*
* COMEDI_INSNLIST
* synchronous instructions
*
* arg:
* pointer to sync cmd structure
*
* reads:
* sync cmd struct at arg
* instruction list
* data (for writes)
*
* writes:
* data (for reads)
*/
/* arbitrary limits */
#define MAX_SAMPLES 256
static int do_insnlist_ioctl(struct comedi_device *dev,
struct comedi_insnlist __user *arg, void *file)
{
struct comedi_insnlist insnlist;
struct comedi_insn *insns = NULL;
unsigned int *data = NULL;
int i = 0;
int ret = 0;
if (copy_from_user(&insnlist, arg, sizeof(struct comedi_insnlist)))
return -EFAULT;
data = kmalloc(sizeof(unsigned int) * MAX_SAMPLES, GFP_KERNEL);
if (!data) {
DPRINTK("kmalloc failed\n");
ret = -ENOMEM;
goto error;
}
insns =
kcalloc(insnlist.n_insns, sizeof(struct comedi_insn), GFP_KERNEL);
if (!insns) {
DPRINTK("kmalloc failed\n");
ret = -ENOMEM;
goto error;
}
if (copy_from_user(insns, insnlist.insns,
sizeof(struct comedi_insn) * insnlist.n_insns)) {
DPRINTK("copy_from_user failed\n");
ret = -EFAULT;
goto error;
}
for (i = 0; i < insnlist.n_insns; i++) {
if (insns[i].n > MAX_SAMPLES) {
DPRINTK("number of samples too large\n");
ret = -EINVAL;
goto error;
}
if (insns[i].insn & INSN_MASK_WRITE) {
if (copy_from_user(data, insns[i].data,
insns[i].n * sizeof(unsigned int))) {
DPRINTK("copy_from_user failed\n");
ret = -EFAULT;
goto error;
}
}
ret = parse_insn(dev, insns + i, data, file);
if (ret < 0)
goto error;
if (insns[i].insn & INSN_MASK_READ) {
if (copy_to_user(insns[i].data, data,
insns[i].n * sizeof(unsigned int))) {
DPRINTK("copy_to_user failed\n");
ret = -EFAULT;
goto error;
}
}
if (need_resched())
schedule();
}
error:
kfree(insns);
kfree(data);
if (ret < 0)
return ret;
return i;
}
static int check_insn_config_length(struct comedi_insn *insn,
unsigned int *data)
{
if (insn->n < 1)
return -EINVAL;
switch (data[0]) {
case INSN_CONFIG_DIO_OUTPUT:
case INSN_CONFIG_DIO_INPUT:
case INSN_CONFIG_DISARM:
case INSN_CONFIG_RESET:
if (insn->n == 1)
return 0;
break;
case INSN_CONFIG_ARM:
case INSN_CONFIG_DIO_QUERY:
case INSN_CONFIG_BLOCK_SIZE:
case INSN_CONFIG_FILTER:
case INSN_CONFIG_SERIAL_CLOCK:
case INSN_CONFIG_BIDIRECTIONAL_DATA:
case INSN_CONFIG_ALT_SOURCE:
case INSN_CONFIG_SET_COUNTER_MODE:
case INSN_CONFIG_8254_READ_STATUS:
case INSN_CONFIG_SET_ROUTING:
case INSN_CONFIG_GET_ROUTING:
case INSN_CONFIG_GET_PWM_STATUS:
case INSN_CONFIG_PWM_SET_PERIOD:
case INSN_CONFIG_PWM_GET_PERIOD:
if (insn->n == 2)
return 0;
break;
case INSN_CONFIG_SET_GATE_SRC:
case INSN_CONFIG_GET_GATE_SRC:
case INSN_CONFIG_SET_CLOCK_SRC:
case INSN_CONFIG_GET_CLOCK_SRC:
case INSN_CONFIG_SET_OTHER_SRC:
case INSN_CONFIG_GET_COUNTER_STATUS:
case INSN_CONFIG_PWM_SET_H_BRIDGE:
case INSN_CONFIG_PWM_GET_H_BRIDGE:
case INSN_CONFIG_GET_HARDWARE_BUFFER_SIZE:
if (insn->n == 3)
return 0;
break;
case INSN_CONFIG_PWM_OUTPUT:
case INSN_CONFIG_ANALOG_TRIG:
if (insn->n == 5)
return 0;
break;
/* by default we allow the insn since we don't have checks for
* all possible cases yet */
default:
printk(KERN_WARNING
"comedi: no check for data length of config insn id "
"%i is implemented.\n"
" Add a check to %s in %s.\n"
" Assuming n=%i is correct.\n", data[0], __func__,
__FILE__, insn->n);
return 0;
break;
}
return -EINVAL;
}
static int parse_insn(struct comedi_device *dev, struct comedi_insn *insn,
unsigned int *data, void *file)
{
struct comedi_subdevice *s;
int ret = 0;
int i;
if (insn->insn & INSN_MASK_SPECIAL) {
/* a non-subdevice instruction */
switch (insn->insn) {
case INSN_GTOD:
{
struct timeval tv;
if (insn->n != 2) {
ret = -EINVAL;
break;
}
do_gettimeofday(&tv);
data[0] = tv.tv_sec;
data[1] = tv.tv_usec;
ret = 2;
break;
}
case INSN_WAIT:
if (insn->n != 1 || data[0] >= 100000) {
ret = -EINVAL;
break;
}
udelay(data[0] / 1000);
ret = 1;
break;
case INSN_INTTRIG:
if (insn->n != 1) {
ret = -EINVAL;
break;
}
if (insn->subdev >= dev->n_subdevices) {
DPRINTK("%d not usable subdevice\n",
insn->subdev);
ret = -EINVAL;
break;
}
s = dev->subdevices + insn->subdev;
if (!s->async) {
DPRINTK("no async\n");
ret = -EINVAL;
break;
}
if (!s->async->inttrig) {
DPRINTK("no inttrig\n");
ret = -EAGAIN;
break;
}
ret = s->async->inttrig(dev, s, data[0]);
if (ret >= 0)
ret = 1;
break;
default:
DPRINTK("invalid insn\n");
ret = -EINVAL;
break;
}
} else {
/* a subdevice instruction */
unsigned int maxdata;
if (insn->subdev >= dev->n_subdevices) {
DPRINTK("subdevice %d out of range\n", insn->subdev);
ret = -EINVAL;
goto out;
}
s = dev->subdevices + insn->subdev;
if (s->type == COMEDI_SUBD_UNUSED) {
DPRINTK("%d not usable subdevice\n", insn->subdev);
ret = -EIO;
goto out;
}
/* are we locked? (ioctl lock) */
if (s->lock && s->lock != file) {
DPRINTK("device locked\n");
ret = -EACCES;
goto out;
}
ret = comedi_check_chanlist(s, 1, &insn->chanspec);
if (ret < 0) {
ret = -EINVAL;
DPRINTK("bad chanspec\n");
goto out;
}
if (s->busy) {
ret = -EBUSY;
goto out;
}
/* This looks arbitrary. It is. */
s->busy = &parse_insn;
switch (insn->insn) {
case INSN_READ:
ret = s->insn_read(dev, s, insn, data);
break;
case INSN_WRITE:
maxdata = s->maxdata_list
? s->maxdata_list[CR_CHAN(insn->chanspec)]
: s->maxdata;
for (i = 0; i < insn->n; ++i) {
if (data[i] > maxdata) {
ret = -EINVAL;
DPRINTK("bad data value(s)\n");
break;
}
}
if (ret == 0)
ret = s->insn_write(dev, s, insn, data);
break;
case INSN_BITS:
if (insn->n != 2) {
ret = -EINVAL;
} else {
/* Most drivers ignore the base channel in
* insn->chanspec. Fix this here if
* the subdevice has <= 32 channels. */
unsigned int shift;
unsigned int orig_mask;
orig_mask = data[0];
if (s->n_chan <= 32) {
shift = CR_CHAN(insn->chanspec);
if (shift > 0) {
insn->chanspec = 0;
data[0] <<= shift;
data[1] <<= shift;
}
} else
shift = 0;
ret = s->insn_bits(dev, s, insn, data);
data[0] = orig_mask;
if (shift > 0)
data[1] >>= shift;
}
break;
case INSN_CONFIG:
ret = check_insn_config_length(insn, data);
if (ret)
break;
ret = s->insn_config(dev, s, insn, data);
break;
default:
ret = -EINVAL;
break;
}
s->busy = NULL;
}
out:
return ret;
}
/*
* COMEDI_INSN
* synchronous instructions
*
* arg:
* pointer to insn
*
* reads:
* struct comedi_insn struct at arg
* data (for writes)
*
* writes:
* data (for reads)
*/
static int do_insn_ioctl(struct comedi_device *dev,
struct comedi_insn __user *arg, void *file)
{
struct comedi_insn insn;
unsigned int *data = NULL;
int ret = 0;
data = kmalloc(sizeof(unsigned int) * MAX_SAMPLES, GFP_KERNEL);
if (!data) {
ret = -ENOMEM;
goto error;
}
if (copy_from_user(&insn, arg, sizeof(struct comedi_insn))) {
ret = -EFAULT;
goto error;
}
/* This is where the behavior of insn and insnlist deviate. */
if (insn.n > MAX_SAMPLES)
insn.n = MAX_SAMPLES;
if (insn.insn & INSN_MASK_WRITE) {
if (copy_from_user(data,
insn.data,
insn.n * sizeof(unsigned int))) {
ret = -EFAULT;
goto error;
}
}
ret = parse_insn(dev, &insn, data, file);
if (ret < 0)
goto error;
if (insn.insn & INSN_MASK_READ) {
if (copy_to_user(insn.data,
data,
insn.n * sizeof(unsigned int))) {
ret = -EFAULT;
goto error;
}
}
ret = insn.n;
error:
kfree(data);
return ret;
}
static void comedi_set_subdevice_runflags(struct comedi_subdevice *s,
unsigned mask, unsigned bits)
{
unsigned long flags;
spin_lock_irqsave(&s->spin_lock, flags);
s->runflags &= ~mask;
s->runflags |= (bits & mask);
spin_unlock_irqrestore(&s->spin_lock, flags);
}
static int do_cmd_ioctl(struct comedi_device *dev,
struct comedi_cmd __user *cmd, void *file)
{
struct comedi_cmd user_cmd;
struct comedi_subdevice *s;
struct comedi_async *async;
int ret = 0;
unsigned int __user *chanlist_saver = NULL;
if (copy_from_user(&user_cmd, cmd, sizeof(struct comedi_cmd))) {
DPRINTK("bad cmd address\n");
return -EFAULT;
}
/* save user's chanlist pointer so it can be restored later */
chanlist_saver = user_cmd.chanlist;
if (user_cmd.subdev >= dev->n_subdevices) {
DPRINTK("%d no such subdevice\n", user_cmd.subdev);
return -ENODEV;
}
s = dev->subdevices + user_cmd.subdev;
async = s->async;
if (s->type == COMEDI_SUBD_UNUSED) {
DPRINTK("%d not valid subdevice\n", user_cmd.subdev);
return -EIO;
}
if (!s->do_cmd || !s->do_cmdtest || !s->async) {
DPRINTK("subdevice %i does not support commands\n",
user_cmd.subdev);
return -EIO;
}
/* are we locked? (ioctl lock) */
if (s->lock && s->lock != file) {
DPRINTK("subdevice locked\n");
return -EACCES;
}
/* are we busy? */
if (s->busy) {
DPRINTK("subdevice busy\n");
return -EBUSY;
}
s->busy = file;
/* make sure channel/gain list isn't too long */
if (user_cmd.chanlist_len > s->len_chanlist) {
DPRINTK("channel/gain list too long %u > %d\n",
user_cmd.chanlist_len, s->len_chanlist);
ret = -EINVAL;
goto cleanup;
}
/* make sure channel/gain list isn't too short */
if (user_cmd.chanlist_len < 1) {
DPRINTK("channel/gain list too short %u < 1\n",
user_cmd.chanlist_len);
ret = -EINVAL;
goto cleanup;
}
async->cmd = user_cmd;
async->cmd.data = NULL;
/* load channel/gain list */
async->cmd.chanlist =
kmalloc(async->cmd.chanlist_len * sizeof(int), GFP_KERNEL);
if (!async->cmd.chanlist) {
DPRINTK("allocation failed\n");
ret = -ENOMEM;
goto cleanup;
}
if (copy_from_user(async->cmd.chanlist, user_cmd.chanlist,
async->cmd.chanlist_len * sizeof(int))) {
DPRINTK("fault reading chanlist\n");
ret = -EFAULT;
goto cleanup;
}
/* make sure each element in channel/gain list is valid */
ret = comedi_check_chanlist(s,
async->cmd.chanlist_len,
async->cmd.chanlist);
if (ret < 0) {
DPRINTK("bad chanlist\n");
goto cleanup;
}
ret = s->do_cmdtest(dev, s, &async->cmd);
if (async->cmd.flags & TRIG_BOGUS || ret) {
DPRINTK("test returned %d\n", ret);
user_cmd = async->cmd;
/* restore chanlist pointer before copying back */
user_cmd.chanlist = chanlist_saver;
user_cmd.data = NULL;
if (copy_to_user(cmd, &user_cmd, sizeof(struct comedi_cmd))) {
DPRINTK("fault writing cmd\n");
ret = -EFAULT;
goto cleanup;
}
ret = -EAGAIN;
goto cleanup;
}
if (!async->prealloc_bufsz) {
ret = -ENOMEM;
DPRINTK("no buffer (?)\n");
goto cleanup;
}
comedi_reset_async_buf(async);
async->cb_mask =
COMEDI_CB_EOA | COMEDI_CB_BLOCK | COMEDI_CB_ERROR |
COMEDI_CB_OVERFLOW;
if (async->cmd.flags & TRIG_WAKE_EOS)
async->cb_mask |= COMEDI_CB_EOS;
comedi_set_subdevice_runflags(s, ~0, SRF_USER | SRF_RUNNING);
ret = s->do_cmd(dev, s);
if (ret == 0)
return 0;
cleanup:
do_become_nonbusy(dev, s);
return ret;
}
/*
COMEDI_CMDTEST
command testing ioctl
arg:
pointer to cmd structure
reads:
cmd structure at arg
channel/range list
writes:
modified cmd structure at arg
*/
static int do_cmdtest_ioctl(struct comedi_device *dev,
struct comedi_cmd __user *arg, void *file)
{
struct comedi_cmd user_cmd;
struct comedi_subdevice *s;
int ret = 0;
unsigned int *chanlist = NULL;
unsigned int __user *chanlist_saver = NULL;
if (copy_from_user(&user_cmd, arg, sizeof(struct comedi_cmd))) {
DPRINTK("bad cmd address\n");
return -EFAULT;
}
/* save user's chanlist pointer so it can be restored later */
chanlist_saver = user_cmd.chanlist;
if (user_cmd.subdev >= dev->n_subdevices) {
DPRINTK("%d no such subdevice\n", user_cmd.subdev);
return -ENODEV;
}
s = dev->subdevices + user_cmd.subdev;
if (s->type == COMEDI_SUBD_UNUSED) {
DPRINTK("%d not valid subdevice\n", user_cmd.subdev);
return -EIO;
}
if (!s->do_cmd || !s->do_cmdtest) {
DPRINTK("subdevice %i does not support commands\n",
user_cmd.subdev);
return -EIO;
}
/* make sure channel/gain list isn't too long */
if (user_cmd.chanlist_len > s->len_chanlist) {
DPRINTK("channel/gain list too long %d > %d\n",
user_cmd.chanlist_len, s->len_chanlist);
ret = -EINVAL;
goto cleanup;
}
/* load channel/gain list */
if (user_cmd.chanlist) {
chanlist =
kmalloc(user_cmd.chanlist_len * sizeof(int), GFP_KERNEL);
if (!chanlist) {
DPRINTK("allocation failed\n");
ret = -ENOMEM;
goto cleanup;
}
if (copy_from_user(chanlist, user_cmd.chanlist,
user_cmd.chanlist_len * sizeof(int))) {
DPRINTK("fault reading chanlist\n");
ret = -EFAULT;
goto cleanup;
}
/* make sure each element in channel/gain list is valid */
ret = comedi_check_chanlist(s, user_cmd.chanlist_len, chanlist);
if (ret < 0) {
DPRINTK("bad chanlist\n");
goto cleanup;
}
user_cmd.chanlist = chanlist;
}
ret = s->do_cmdtest(dev, s, &user_cmd);
/* restore chanlist pointer before copying back */
user_cmd.chanlist = chanlist_saver;
if (copy_to_user(arg, &user_cmd, sizeof(struct comedi_cmd))) {
DPRINTK("bad cmd address\n");
ret = -EFAULT;
goto cleanup;
}
cleanup:
kfree(chanlist);
return ret;
}
/*
COMEDI_LOCK
lock subdevice
arg:
subdevice number
reads:
none
writes:
none
*/
static int do_lock_ioctl(struct comedi_device *dev, unsigned int arg,
void *file)
{
int ret = 0;
unsigned long flags;
struct comedi_subdevice *s;
if (arg >= dev->n_subdevices)
return -EINVAL;
s = dev->subdevices + arg;
spin_lock_irqsave(&s->spin_lock, flags);
if (s->busy || s->lock)
ret = -EBUSY;
else
s->lock = file;
spin_unlock_irqrestore(&s->spin_lock, flags);
#if 0
if (ret < 0)
return ret;
if (s->lock_f)
ret = s->lock_f(dev, s);
#endif
return ret;
}
/*
COMEDI_UNLOCK
unlock subdevice
arg:
subdevice number
reads:
none
writes:
none
This function isn't protected by the semaphore, since
we already own the lock.
*/
static int do_unlock_ioctl(struct comedi_device *dev, unsigned int arg,
void *file)
{
struct comedi_subdevice *s;
if (arg >= dev->n_subdevices)
return -EINVAL;
s = dev->subdevices + arg;
if (s->busy)
return -EBUSY;
if (s->lock && s->lock != file)
return -EACCES;
if (s->lock == file) {
#if 0
if (s->unlock)
s->unlock(dev, s);
#endif
s->lock = NULL;
}
return 0;
}
/*
COMEDI_CANCEL
cancel acquisition ioctl
arg:
subdevice number
reads:
nothing
writes:
nothing
*/
static int do_cancel_ioctl(struct comedi_device *dev, unsigned int arg,
void *file)
{
struct comedi_subdevice *s;
int ret;
if (arg >= dev->n_subdevices)
return -EINVAL;
s = dev->subdevices + arg;
if (s->async == NULL)
return -EINVAL;
if (s->lock && s->lock != file)
return -EACCES;
if (!s->busy)
return 0;
if (s->busy != file)
return -EBUSY;
ret = do_cancel(dev, s);
if (comedi_get_subdevice_runflags(s) & SRF_USER)
wake_up_interruptible(&s->async->wait_head);
return ret;
}
/*
COMEDI_POLL ioctl
instructs driver to synchronize buffers
arg:
subdevice number
reads:
nothing
writes:
nothing
*/
static int do_poll_ioctl(struct comedi_device *dev, unsigned int arg,
void *file)
{
struct comedi_subdevice *s;
if (arg >= dev->n_subdevices)
return -EINVAL;
s = dev->subdevices + arg;
if (s->lock && s->lock != file)
return -EACCES;
if (!s->busy)
return 0;
if (s->busy != file)
return -EBUSY;
if (s->poll)
return s->poll(dev, s);
return -EINVAL;
}
static int do_cancel(struct comedi_device *dev, struct comedi_subdevice *s)
{
int ret = 0;
if ((comedi_get_subdevice_runflags(s) & SRF_RUNNING) && s->cancel)
ret = s->cancel(dev, s);
do_become_nonbusy(dev, s);
return ret;
}
static void comedi_vm_open(struct vm_area_struct *area)
{
struct comedi_async *async;
struct comedi_device *dev;
async = area->vm_private_data;
dev = async->subdevice->device;
mutex_lock(&dev->mutex);
async->mmap_count++;
mutex_unlock(&dev->mutex);
}
static void comedi_vm_close(struct vm_area_struct *area)
{
struct comedi_async *async;
struct comedi_device *dev;
async = area->vm_private_data;
dev = async->subdevice->device;
mutex_lock(&dev->mutex);
async->mmap_count--;
mutex_unlock(&dev->mutex);
}
static struct vm_operations_struct comedi_vm_ops = {
.open = comedi_vm_open,
.close = comedi_vm_close,
};
static int comedi_mmap(struct file *file, struct vm_area_struct *vma)
{
const unsigned minor = iminor(file->f_dentry->d_inode);
struct comedi_async *async = NULL;
unsigned long start = vma->vm_start;
unsigned long size;
int n_pages;
int i;
int retval;
struct comedi_subdevice *s;
struct comedi_device_file_info *dev_file_info;
struct comedi_device *dev;
dev_file_info = comedi_get_device_file_info(minor);
if (dev_file_info == NULL)
return -ENODEV;
dev = dev_file_info->device;
if (dev == NULL)
return -ENODEV;
mutex_lock(&dev->mutex);
if (!dev->attached) {
DPRINTK("no driver configured on comedi%i\n", dev->minor);
retval = -ENODEV;
goto done;
}
if (vma->vm_flags & VM_WRITE)
s = comedi_get_write_subdevice(dev_file_info);
else
s = comedi_get_read_subdevice(dev_file_info);
if (s == NULL) {
retval = -EINVAL;
goto done;
}
async = s->async;
if (async == NULL) {
retval = -EINVAL;
goto done;
}
if (vma->vm_pgoff != 0) {
DPRINTK("comedi: mmap() offset must be 0.\n");
retval = -EINVAL;
goto done;
}
size = vma->vm_end - vma->vm_start;
if (size > async->prealloc_bufsz) {
retval = -EFAULT;
goto done;
}
if (size & (~PAGE_MASK)) {
retval = -EFAULT;
goto done;
}
n_pages = size >> PAGE_SHIFT;
for (i = 0; i < n_pages; ++i) {
if (remap_pfn_range(vma, start,
page_to_pfn(virt_to_page
(async->buf_page_list
[i].virt_addr)), PAGE_SIZE,
PAGE_SHARED)) {
retval = -EAGAIN;
goto done;
}
start += PAGE_SIZE;
}
vma->vm_ops = &comedi_vm_ops;
vma->vm_private_data = async;
async->mmap_count++;
retval = 0;
done:
mutex_unlock(&dev->mutex);
return retval;
}
static unsigned int comedi_poll(struct file *file, poll_table * wait)
{
unsigned int mask = 0;
const unsigned minor = iminor(file->f_dentry->d_inode);
struct comedi_subdevice *read_subdev;
struct comedi_subdevice *write_subdev;
struct comedi_device_file_info *dev_file_info;
struct comedi_device *dev;
dev_file_info = comedi_get_device_file_info(minor);
if (dev_file_info == NULL)
return -ENODEV;
dev = dev_file_info->device;
if (dev == NULL)
return -ENODEV;
mutex_lock(&dev->mutex);
if (!dev->attached) {
DPRINTK("no driver configured on comedi%i\n", dev->minor);
mutex_unlock(&dev->mutex);
return 0;
}
mask = 0;
read_subdev = comedi_get_read_subdevice(dev_file_info);
if (read_subdev && read_subdev->async) {
poll_wait(file, &read_subdev->async->wait_head, wait);
if (!read_subdev->busy
|| comedi_buf_read_n_available(read_subdev->async) > 0
|| !(comedi_get_subdevice_runflags(read_subdev) &
SRF_RUNNING)) {
mask |= POLLIN | POLLRDNORM;
}
}
write_subdev = comedi_get_write_subdevice(dev_file_info);
if (write_subdev && write_subdev->async) {
poll_wait(file, &write_subdev->async->wait_head, wait);
comedi_buf_write_alloc(write_subdev->async,
write_subdev->async->prealloc_bufsz);
if (!write_subdev->busy
|| !(comedi_get_subdevice_runflags(write_subdev) &
SRF_RUNNING)
|| comedi_buf_write_n_allocated(write_subdev->async) >=
bytes_per_sample(write_subdev->async->subdevice)) {
mask |= POLLOUT | POLLWRNORM;
}
}
mutex_unlock(&dev->mutex);
return mask;
}
static ssize_t comedi_write(struct file *file, const char __user *buf,
size_t nbytes, loff_t *offset)
{
struct comedi_subdevice *s;
struct comedi_async *async;
int n, m, count = 0, retval = 0;
DECLARE_WAITQUEUE(wait, current);
const unsigned minor = iminor(file->f_dentry->d_inode);
struct comedi_device_file_info *dev_file_info;
struct comedi_device *dev;
dev_file_info = comedi_get_device_file_info(minor);
if (dev_file_info == NULL)
return -ENODEV;
dev = dev_file_info->device;
if (dev == NULL)
return -ENODEV;
if (!dev->attached) {
DPRINTK("no driver configured on comedi%i\n", dev->minor);
retval = -ENODEV;
goto done;
}
s = comedi_get_write_subdevice(dev_file_info);
if (s == NULL || s->async == NULL) {
retval = -EIO;
goto done;
}
async = s->async;
if (!nbytes) {
retval = 0;
goto done;
}
if (!s->busy) {
retval = 0;
goto done;
}
if (s->busy != file) {
retval = -EACCES;
goto done;
}
add_wait_queue(&async->wait_head, &wait);
while (nbytes > 0 && !retval) {
set_current_state(TASK_INTERRUPTIBLE);
if (!(comedi_get_subdevice_runflags(s) & SRF_RUNNING)) {
if (count == 0) {
if (comedi_get_subdevice_runflags(s) &
SRF_ERROR) {
retval = -EPIPE;
} else {
retval = 0;
}
do_become_nonbusy(dev, s);
}
break;
}
n = nbytes;
m = n;
if (async->buf_write_ptr + m > async->prealloc_bufsz)
m = async->prealloc_bufsz - async->buf_write_ptr;
comedi_buf_write_alloc(async, async->prealloc_bufsz);
if (m > comedi_buf_write_n_allocated(async))
m = comedi_buf_write_n_allocated(async);
if (m < n)
n = m;
if (n == 0) {
if (file->f_flags & O_NONBLOCK) {
retval = -EAGAIN;
break;
}
schedule();
if (signal_pending(current)) {
retval = -ERESTARTSYS;
break;
}
if (!s->busy)
break;
if (s->busy != file) {
retval = -EACCES;
break;
}
continue;
}
m = copy_from_user(async->prealloc_buf + async->buf_write_ptr,
buf, n);
if (m) {
n -= m;
retval = -EFAULT;
}
comedi_buf_write_free(async, n);
count += n;
nbytes -= n;
buf += n;
break; /* makes device work like a pipe */
}
set_current_state(TASK_RUNNING);
remove_wait_queue(&async->wait_head, &wait);
done:
return count ? count : retval;
}
static ssize_t comedi_read(struct file *file, char __user *buf, size_t nbytes,
loff_t *offset)
{
struct comedi_subdevice *s;
struct comedi_async *async;
int n, m, count = 0, retval = 0;
DECLARE_WAITQUEUE(wait, current);
const unsigned minor = iminor(file->f_dentry->d_inode);
struct comedi_device_file_info *dev_file_info;
struct comedi_device *dev;
dev_file_info = comedi_get_device_file_info(minor);
if (dev_file_info == NULL)
return -ENODEV;
dev = dev_file_info->device;
if (dev == NULL)
return -ENODEV;
if (!dev->attached) {
DPRINTK("no driver configured on comedi%i\n", dev->minor);
retval = -ENODEV;
goto done;
}
s = comedi_get_read_subdevice(dev_file_info);
if (s == NULL || s->async == NULL) {
retval = -EIO;
goto done;
}
async = s->async;
if (!nbytes) {
retval = 0;
goto done;
}
if (!s->busy) {
retval = 0;
goto done;
}
if (s->busy != file) {
retval = -EACCES;
goto done;
}
add_wait_queue(&async->wait_head, &wait);
while (nbytes > 0 && !retval) {
set_current_state(TASK_INTERRUPTIBLE);
n = nbytes;
m = comedi_buf_read_n_available(async);
/* printk("%d available\n",m); */
if (async->buf_read_ptr + m > async->prealloc_bufsz)
m = async->prealloc_bufsz - async->buf_read_ptr;
/* printk("%d contiguous\n",m); */
if (m < n)
n = m;
if (n == 0) {
if (!(comedi_get_subdevice_runflags(s) & SRF_RUNNING)) {
do_become_nonbusy(dev, s);
if (comedi_get_subdevice_runflags(s) &
SRF_ERROR) {
retval = -EPIPE;
} else {
retval = 0;
}
break;
}
if (file->f_flags & O_NONBLOCK) {
retval = -EAGAIN;
break;
}
schedule();
if (signal_pending(current)) {
retval = -ERESTARTSYS;
break;
}
if (!s->busy) {
retval = 0;
break;
}
if (s->busy != file) {
retval = -EACCES;
break;
}
continue;
}
m = copy_to_user(buf, async->prealloc_buf +
async->buf_read_ptr, n);
if (m) {
n -= m;
retval = -EFAULT;
}
comedi_buf_read_alloc(async, n);
comedi_buf_read_free(async, n);
count += n;
nbytes -= n;
buf += n;
break; /* makes device work like a pipe */
}
if (!(comedi_get_subdevice_runflags(s) & (SRF_ERROR | SRF_RUNNING)) &&
async->buf_read_count - async->buf_write_count == 0) {
do_become_nonbusy(dev, s);
}
set_current_state(TASK_RUNNING);
remove_wait_queue(&async->wait_head, &wait);
done:
return count ? count : retval;
}
/*
This function restores a subdevice to an idle state.
*/
void do_become_nonbusy(struct comedi_device *dev, struct comedi_subdevice *s)
{
struct comedi_async *async = s->async;
comedi_set_subdevice_runflags(s, SRF_RUNNING, 0);
if (async) {
comedi_reset_async_buf(async);
async->inttrig = NULL;
kfree(async->cmd.chanlist);
async->cmd.chanlist = NULL;
} else {
printk(KERN_ERR
"BUG: (?) do_become_nonbusy called with async=0\n");
}
s->busy = NULL;
}
static int comedi_open(struct inode *inode, struct file *file)
{
const unsigned minor = iminor(inode);
struct comedi_device_file_info *dev_file_info =
comedi_get_device_file_info(minor);
struct comedi_device *dev =
dev_file_info ? dev_file_info->device : NULL;
if (dev == NULL) {
DPRINTK("invalid minor number\n");
return -ENODEV;
}
/* This is slightly hacky, but we want module autoloading
* to work for root.
* case: user opens device, attached -> ok
* case: user opens device, unattached, in_request_module=0 -> autoload
* case: user opens device, unattached, in_request_module=1 -> fail
* case: root opens device, attached -> ok
* case: root opens device, unattached, in_request_module=1 -> ok
* (typically called from modprobe)
* case: root opens device, unattached, in_request_module=0 -> autoload
*
* The last could be changed to "-> ok", which would deny root
* autoloading.
*/
mutex_lock(&dev->mutex);
if (dev->attached)
goto ok;
if (!capable(CAP_NET_ADMIN) && dev->in_request_module) {
DPRINTK("in request module\n");
mutex_unlock(&dev->mutex);
return -ENODEV;
}
if (capable(CAP_NET_ADMIN) && dev->in_request_module)
goto ok;
dev->in_request_module = 1;
#ifdef CONFIG_KMOD
mutex_unlock(&dev->mutex);
request_module("char-major-%i-%i", COMEDI_MAJOR, dev->minor);
mutex_lock(&dev->mutex);
#endif
dev->in_request_module = 0;
if (!dev->attached && !capable(CAP_NET_ADMIN)) {
DPRINTK("not attached and not CAP_NET_ADMIN\n");
mutex_unlock(&dev->mutex);
return -ENODEV;
}
ok:
__module_get(THIS_MODULE);
if (dev->attached) {
if (!try_module_get(dev->driver->module)) {
module_put(THIS_MODULE);
mutex_unlock(&dev->mutex);
return -ENOSYS;
}
}
if (dev->attached && dev->use_count == 0 && dev->open) {
int rc = dev->open(dev);
if (rc < 0) {
module_put(dev->driver->module);
module_put(THIS_MODULE);
mutex_unlock(&dev->mutex);
return rc;
}
}
dev->use_count++;
mutex_unlock(&dev->mutex);
return 0;
}
static int comedi_close(struct inode *inode, struct file *file)
{
const unsigned minor = iminor(inode);
struct comedi_subdevice *s = NULL;
int i;
struct comedi_device_file_info *dev_file_info;
struct comedi_device *dev;
dev_file_info = comedi_get_device_file_info(minor);
if (dev_file_info == NULL)
return -ENODEV;
dev = dev_file_info->device;
if (dev == NULL)
return -ENODEV;
mutex_lock(&dev->mutex);
if (dev->subdevices) {
for (i = 0; i < dev->n_subdevices; i++) {
s = dev->subdevices + i;
if (s->busy == file)
do_cancel(dev, s);
if (s->lock == file)
s->lock = NULL;
}
}
if (dev->attached && dev->use_count == 1 && dev->close)
dev->close(dev);
module_put(THIS_MODULE);
if (dev->attached)
module_put(dev->driver->module);
dev->use_count--;
mutex_unlock(&dev->mutex);
if (file->f_flags & FASYNC)
comedi_fasync(-1, file, 0);
return 0;
}
static int comedi_fasync(int fd, struct file *file, int on)
{
const unsigned minor = iminor(file->f_dentry->d_inode);
struct comedi_device_file_info *dev_file_info;
struct comedi_device *dev;
dev_file_info = comedi_get_device_file_info(minor);
if (dev_file_info == NULL)
return -ENODEV;
dev = dev_file_info->device;
if (dev == NULL)
return -ENODEV;
return fasync_helper(fd, file, on, &dev->async_queue);
}
const struct file_operations comedi_fops = {
.owner = THIS_MODULE,
.unlocked_ioctl = comedi_unlocked_ioctl,
.compat_ioctl = comedi_compat_ioctl,
.open = comedi_open,
.release = comedi_close,
.read = comedi_read,
.write = comedi_write,
.mmap = comedi_mmap,
.poll = comedi_poll,
.fasync = comedi_fasync,
.llseek = noop_llseek,
};
struct class *comedi_class;
static struct cdev comedi_cdev;
static void comedi_cleanup_legacy_minors(void)
{
unsigned i;
for (i = 0; i < comedi_num_legacy_minors; i++)
comedi_free_board_minor(i);
}
static int __init comedi_init(void)
{
int i;
int retval;
printk(KERN_INFO "comedi: version " COMEDI_RELEASE
" - http://www.comedi.org\n");
if (comedi_num_legacy_minors < 0 ||
comedi_num_legacy_minors > COMEDI_NUM_BOARD_MINORS) {
printk(KERN_ERR "comedi: error: invalid value for module "
"parameter \"comedi_num_legacy_minors\". Valid values "
"are 0 through %i.\n", COMEDI_NUM_BOARD_MINORS);
return -EINVAL;
}
/*
* comedi is unusable if both comedi_autoconfig and
* comedi_num_legacy_minors are zero, so we might as well adjust the
* defaults in that case
*/
if (comedi_autoconfig == 0 && comedi_num_legacy_minors == 0)
comedi_num_legacy_minors = 16;
memset(comedi_file_info_table, 0,
sizeof(struct comedi_device_file_info *) * COMEDI_NUM_MINORS);
retval = register_chrdev_region(MKDEV(COMEDI_MAJOR, 0),
COMEDI_NUM_MINORS, "comedi");
if (retval)
return -EIO;
cdev_init(&comedi_cdev, &comedi_fops);
comedi_cdev.owner = THIS_MODULE;
kobject_set_name(&comedi_cdev.kobj, "comedi");
if (cdev_add(&comedi_cdev, MKDEV(COMEDI_MAJOR, 0), COMEDI_NUM_MINORS)) {
unregister_chrdev_region(MKDEV(COMEDI_MAJOR, 0),
COMEDI_NUM_MINORS);
return -EIO;
}
comedi_class = class_create(THIS_MODULE, "comedi");
if (IS_ERR(comedi_class)) {
printk(KERN_ERR "comedi: failed to create class");
cdev_del(&comedi_cdev);
unregister_chrdev_region(MKDEV(COMEDI_MAJOR, 0),
COMEDI_NUM_MINORS);
return PTR_ERR(comedi_class);
}
/* XXX requires /proc interface */
comedi_proc_init();
/* create devices files for legacy/manual use */
for (i = 0; i < comedi_num_legacy_minors; i++) {
int minor;
minor = comedi_alloc_board_minor(NULL);
if (minor < 0) {
comedi_cleanup_legacy_minors();
cdev_del(&comedi_cdev);
unregister_chrdev_region(MKDEV(COMEDI_MAJOR, 0),
COMEDI_NUM_MINORS);
return minor;
}
}
return 0;
}
static void __exit comedi_cleanup(void)
{
int i;
comedi_cleanup_legacy_minors();
for (i = 0; i < COMEDI_NUM_MINORS; ++i)
BUG_ON(comedi_file_info_table[i]);
class_destroy(comedi_class);
cdev_del(&comedi_cdev);
unregister_chrdev_region(MKDEV(COMEDI_MAJOR, 0), COMEDI_NUM_MINORS);
comedi_proc_cleanup();
}
module_init(comedi_init);
module_exit(comedi_cleanup);
void comedi_error(const struct comedi_device *dev, const char *s)
{
printk(KERN_ERR "comedi%d: %s: %s\n", dev->minor,
dev->driver->driver_name, s);
}
EXPORT_SYMBOL(comedi_error);
void comedi_event(struct comedi_device *dev, struct comedi_subdevice *s)
{
struct comedi_async *async = s->async;
unsigned runflags = 0;
unsigned runflags_mask = 0;
/* DPRINTK("comedi_event 0x%x\n",mask); */
if ((comedi_get_subdevice_runflags(s) & SRF_RUNNING) == 0)
return;
if (s->
async->events & (COMEDI_CB_EOA | COMEDI_CB_ERROR |
COMEDI_CB_OVERFLOW)) {
runflags_mask |= SRF_RUNNING;
}
/* remember if an error event has occurred, so an error
* can be returned the next time the user does a read() */
if (s->async->events & (COMEDI_CB_ERROR | COMEDI_CB_OVERFLOW)) {
runflags_mask |= SRF_ERROR;
runflags |= SRF_ERROR;
}
if (runflags_mask) {
/*sets SRF_ERROR and SRF_RUNNING together atomically */
comedi_set_subdevice_runflags(s, runflags_mask, runflags);
}
if (async->cb_mask & s->async->events) {
if (comedi_get_subdevice_runflags(s) & SRF_USER) {
wake_up_interruptible(&async->wait_head);
if (s->subdev_flags & SDF_CMD_READ)
kill_fasync(&dev->async_queue, SIGIO, POLL_IN);
if (s->subdev_flags & SDF_CMD_WRITE)
kill_fasync(&dev->async_queue, SIGIO, POLL_OUT);
} else {
if (async->cb_func)
async->cb_func(s->async->events, async->cb_arg);
}
}
s->async->events = 0;
}
EXPORT_SYMBOL(comedi_event);
unsigned comedi_get_subdevice_runflags(struct comedi_subdevice *s)
{
unsigned long flags;
unsigned runflags;
spin_lock_irqsave(&s->spin_lock, flags);
runflags = s->runflags;
spin_unlock_irqrestore(&s->spin_lock, flags);
return runflags;
}
EXPORT_SYMBOL(comedi_get_subdevice_runflags);
static int is_device_busy(struct comedi_device *dev)
{
struct comedi_subdevice *s;
int i;
if (!dev->attached)
return 0;
for (i = 0; i < dev->n_subdevices; i++) {
s = dev->subdevices + i;
if (s->busy)
return 1;
if (s->async && s->async->mmap_count)
return 1;
}
return 0;
}
static void comedi_device_init(struct comedi_device *dev)
{
memset(dev, 0, sizeof(struct comedi_device));
spin_lock_init(&dev->spinlock);
mutex_init(&dev->mutex);
dev->minor = -1;
}
static void comedi_device_cleanup(struct comedi_device *dev)
{
if (dev == NULL)
return;
mutex_lock(&dev->mutex);
comedi_device_detach(dev);
mutex_unlock(&dev->mutex);
mutex_destroy(&dev->mutex);
}
int comedi_alloc_board_minor(struct device *hardware_device)
{
unsigned long flags;
struct comedi_device_file_info *info;
struct device *csdev;
unsigned i;
int retval;
info = kzalloc(sizeof(struct comedi_device_file_info), GFP_KERNEL);
if (info == NULL)
return -ENOMEM;
info->device = kzalloc(sizeof(struct comedi_device), GFP_KERNEL);
if (info->device == NULL) {
kfree(info);
return -ENOMEM;
}
info->hardware_device = hardware_device;
comedi_device_init(info->device);
spin_lock_irqsave(&comedi_file_info_table_lock, flags);
for (i = 0; i < COMEDI_NUM_BOARD_MINORS; ++i) {
if (comedi_file_info_table[i] == NULL) {
comedi_file_info_table[i] = info;
break;
}
}
spin_unlock_irqrestore(&comedi_file_info_table_lock, flags);
if (i == COMEDI_NUM_BOARD_MINORS) {
comedi_device_cleanup(info->device);
kfree(info->device);
kfree(info);
printk(KERN_ERR
"comedi: error: "
"ran out of minor numbers for board device files.\n");
return -EBUSY;
}
info->device->minor = i;
csdev = device_create(comedi_class, hardware_device,
MKDEV(COMEDI_MAJOR, i), NULL, "comedi%i", i);
if (!IS_ERR(csdev))
info->device->class_dev = csdev;
dev_set_drvdata(csdev, info);
retval = device_create_file(csdev, &dev_attr_max_read_buffer_kb);
if (retval) {
printk(KERN_ERR
"comedi: "
"failed to create sysfs attribute file \"%s\".\n",
dev_attr_max_read_buffer_kb.attr.name);
comedi_free_board_minor(i);
return retval;
}
retval = device_create_file(csdev, &dev_attr_read_buffer_kb);
if (retval) {
printk(KERN_ERR
"comedi: "
"failed to create sysfs attribute file \"%s\".\n",
dev_attr_read_buffer_kb.attr.name);
comedi_free_board_minor(i);
return retval;
}
retval = device_create_file(csdev, &dev_attr_max_write_buffer_kb);
if (retval) {
printk(KERN_ERR
"comedi: "
"failed to create sysfs attribute file \"%s\".\n",
dev_attr_max_write_buffer_kb.attr.name);
comedi_free_board_minor(i);
return retval;
}
retval = device_create_file(csdev, &dev_attr_write_buffer_kb);
if (retval) {
printk(KERN_ERR
"comedi: "
"failed to create sysfs attribute file \"%s\".\n",
dev_attr_write_buffer_kb.attr.name);
comedi_free_board_minor(i);
return retval;
}
return i;
}
void comedi_free_board_minor(unsigned minor)
{
unsigned long flags;
struct comedi_device_file_info *info;
BUG_ON(minor >= COMEDI_NUM_BOARD_MINORS);
spin_lock_irqsave(&comedi_file_info_table_lock, flags);
info = comedi_file_info_table[minor];
comedi_file_info_table[minor] = NULL;
spin_unlock_irqrestore(&comedi_file_info_table_lock, flags);
if (info) {
struct comedi_device *dev = info->device;
if (dev) {
if (dev->class_dev) {
device_destroy(comedi_class,
MKDEV(COMEDI_MAJOR, dev->minor));
}
comedi_device_cleanup(dev);
kfree(dev);
}
kfree(info);
}
}
int comedi_find_board_minor(struct device *hardware_device)
{
int minor;
struct comedi_device_file_info *info;
for (minor = 0; minor < COMEDI_NUM_BOARD_MINORS; minor++) {
spin_lock(&comedi_file_info_table_lock);
info = comedi_file_info_table[minor];
if (info && info->hardware_device == hardware_device) {
spin_unlock(&comedi_file_info_table_lock);
return minor;
}
spin_unlock(&comedi_file_info_table_lock);
}
return -ENODEV;
}
int comedi_alloc_subdevice_minor(struct comedi_device *dev,
struct comedi_subdevice *s)
{
unsigned long flags;
struct comedi_device_file_info *info;
struct device *csdev;
unsigned i;
int retval;
info = kmalloc(sizeof(struct comedi_device_file_info), GFP_KERNEL);
if (info == NULL)
return -ENOMEM;
info->device = dev;
info->read_subdevice = s;
info->write_subdevice = s;
spin_lock_irqsave(&comedi_file_info_table_lock, flags);
for (i = COMEDI_FIRST_SUBDEVICE_MINOR; i < COMEDI_NUM_MINORS; ++i) {
if (comedi_file_info_table[i] == NULL) {
comedi_file_info_table[i] = info;
break;
}
}
spin_unlock_irqrestore(&comedi_file_info_table_lock, flags);
if (i == COMEDI_NUM_MINORS) {
kfree(info);
printk(KERN_ERR
"comedi: error: "
"ran out of minor numbers for board device files.\n");
return -EBUSY;
}
s->minor = i;
csdev = device_create(comedi_class, dev->class_dev,
MKDEV(COMEDI_MAJOR, i), NULL, "comedi%i_subd%i",
dev->minor, (int)(s - dev->subdevices));
if (!IS_ERR(csdev))
s->class_dev = csdev;
dev_set_drvdata(csdev, info);
retval = device_create_file(csdev, &dev_attr_max_read_buffer_kb);
if (retval) {
printk(KERN_ERR
"comedi: "
"failed to create sysfs attribute file \"%s\".\n",
dev_attr_max_read_buffer_kb.attr.name);
comedi_free_subdevice_minor(s);
return retval;
}
retval = device_create_file(csdev, &dev_attr_read_buffer_kb);
if (retval) {
printk(KERN_ERR
"comedi: "
"failed to create sysfs attribute file \"%s\".\n",
dev_attr_read_buffer_kb.attr.name);
comedi_free_subdevice_minor(s);
return retval;
}
retval = device_create_file(csdev, &dev_attr_max_write_buffer_kb);
if (retval) {
printk(KERN_ERR
"comedi: "
"failed to create sysfs attribute file \"%s\".\n",
dev_attr_max_write_buffer_kb.attr.name);
comedi_free_subdevice_minor(s);
return retval;
}
retval = device_create_file(csdev, &dev_attr_write_buffer_kb);
if (retval) {
printk(KERN_ERR
"comedi: "
"failed to create sysfs attribute file \"%s\".\n",
dev_attr_write_buffer_kb.attr.name);
comedi_free_subdevice_minor(s);
return retval;
}
return i;
}
void comedi_free_subdevice_minor(struct comedi_subdevice *s)
{
unsigned long flags;
struct comedi_device_file_info *info;
if (s == NULL)
return;
if (s->minor < 0)
return;
BUG_ON(s->minor >= COMEDI_NUM_MINORS);
BUG_ON(s->minor < COMEDI_FIRST_SUBDEVICE_MINOR);
spin_lock_irqsave(&comedi_file_info_table_lock, flags);
info = comedi_file_info_table[s->minor];
comedi_file_info_table[s->minor] = NULL;
spin_unlock_irqrestore(&comedi_file_info_table_lock, flags);
if (s->class_dev) {
device_destroy(comedi_class, MKDEV(COMEDI_MAJOR, s->minor));
s->class_dev = NULL;
}
kfree(info);
}
struct comedi_device_file_info *comedi_get_device_file_info(unsigned minor)
{
unsigned long flags;
struct comedi_device_file_info *info;
BUG_ON(minor >= COMEDI_NUM_MINORS);
spin_lock_irqsave(&comedi_file_info_table_lock, flags);
info = comedi_file_info_table[minor];
spin_unlock_irqrestore(&comedi_file_info_table_lock, flags);
return info;
}
EXPORT_SYMBOL_GPL(comedi_get_device_file_info);
static int resize_async_buffer(struct comedi_device *dev,
struct comedi_subdevice *s,
struct comedi_async *async, unsigned new_size)
{
int retval;
if (new_size > async->max_bufsize)
return -EPERM;
if (s->busy) {
DPRINTK("subdevice is busy, cannot resize buffer\n");
return -EBUSY;
}
if (async->mmap_count) {
DPRINTK("subdevice is mmapped, cannot resize buffer\n");
return -EBUSY;
}
if (!async->prealloc_buf)
return -EINVAL;
/* make sure buffer is an integral number of pages
* (we round up) */
new_size = (new_size + PAGE_SIZE - 1) & PAGE_MASK;
retval = comedi_buf_alloc(dev, s, new_size);
if (retval < 0)
return retval;
if (s->buf_change) {
retval = s->buf_change(dev, s, new_size);
if (retval < 0)
return retval;
}
DPRINTK("comedi%i subd %d buffer resized to %i bytes\n",
dev->minor, (int)(s - dev->subdevices), async->prealloc_bufsz);
return 0;
}
/* sysfs attribute files */
static const unsigned bytes_per_kibi = 1024;
static ssize_t show_max_read_buffer_kb(struct device *dev,
struct device_attribute *attr, char *buf)
{
ssize_t retval;
struct comedi_device_file_info *info = dev_get_drvdata(dev);
unsigned max_buffer_size_kb = 0;
struct comedi_subdevice *const read_subdevice =
comedi_get_read_subdevice(info);
mutex_lock(&info->device->mutex);
if (read_subdevice &&
(read_subdevice->subdev_flags & SDF_CMD_READ) &&
read_subdevice->async) {
max_buffer_size_kb = read_subdevice->async->max_bufsize /
bytes_per_kibi;
}
retval = snprintf(buf, PAGE_SIZE, "%i\n", max_buffer_size_kb);
mutex_unlock(&info->device->mutex);
return retval;
}
static ssize_t store_max_read_buffer_kb(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct comedi_device_file_info *info = dev_get_drvdata(dev);
unsigned int new_max_size_kb;
unsigned int new_max_size;
int ret;
struct comedi_subdevice *const read_subdevice =
comedi_get_read_subdevice(info);
ret = kstrtouint(buf, 10, &new_max_size_kb);
if (ret)
return ret;
if (new_max_size_kb > (UINT_MAX / bytes_per_kibi))
return -EINVAL;
new_max_size = new_max_size_kb * bytes_per_kibi;
mutex_lock(&info->device->mutex);
if (read_subdevice == NULL ||
(read_subdevice->subdev_flags & SDF_CMD_READ) == 0 ||
read_subdevice->async == NULL) {
mutex_unlock(&info->device->mutex);
return -EINVAL;
}
read_subdevice->async->max_bufsize = new_max_size;
mutex_unlock(&info->device->mutex);
return count;
}
static struct device_attribute dev_attr_max_read_buffer_kb = {
.attr = {
.name = "max_read_buffer_kb",
.mode = S_IRUGO | S_IWUSR},
.show = &show_max_read_buffer_kb,
.store = &store_max_read_buffer_kb
};
static ssize_t show_read_buffer_kb(struct device *dev,
struct device_attribute *attr, char *buf)
{
ssize_t retval;
struct comedi_device_file_info *info = dev_get_drvdata(dev);
unsigned buffer_size_kb = 0;
struct comedi_subdevice *const read_subdevice =
comedi_get_read_subdevice(info);
mutex_lock(&info->device->mutex);
if (read_subdevice &&
(read_subdevice->subdev_flags & SDF_CMD_READ) &&
read_subdevice->async) {
buffer_size_kb = read_subdevice->async->prealloc_bufsz /
bytes_per_kibi;
}
retval = snprintf(buf, PAGE_SIZE, "%i\n", buffer_size_kb);
mutex_unlock(&info->device->mutex);
return retval;
}
static ssize_t store_read_buffer_kb(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct comedi_device_file_info *info = dev_get_drvdata(dev);
unsigned int new_size_kb;
unsigned int new_size;
int retval;
int ret;
struct comedi_subdevice *const read_subdevice =
comedi_get_read_subdevice(info);
ret = kstrtouint(buf, 10, &new_size_kb);
if (ret)
return ret;
if (new_size_kb > (UINT_MAX / bytes_per_kibi))
return -EINVAL;
new_size = new_size_kb * bytes_per_kibi;
mutex_lock(&info->device->mutex);
if (read_subdevice == NULL ||
(read_subdevice->subdev_flags & SDF_CMD_READ) == 0 ||
read_subdevice->async == NULL) {
mutex_unlock(&info->device->mutex);
return -EINVAL;
}
retval = resize_async_buffer(info->device, read_subdevice,
read_subdevice->async, new_size);
mutex_unlock(&info->device->mutex);
if (retval < 0)
return retval;
return count;
}
static struct device_attribute dev_attr_read_buffer_kb = {
.attr = {
.name = "read_buffer_kb",
.mode = S_IRUGO | S_IWUSR | S_IWGRP},
.show = &show_read_buffer_kb,
.store = &store_read_buffer_kb
};
static ssize_t show_max_write_buffer_kb(struct device *dev,
struct device_attribute *attr,
char *buf)
{
ssize_t retval;
struct comedi_device_file_info *info = dev_get_drvdata(dev);
unsigned max_buffer_size_kb = 0;
struct comedi_subdevice *const write_subdevice =
comedi_get_write_subdevice(info);
mutex_lock(&info->device->mutex);
if (write_subdevice &&
(write_subdevice->subdev_flags & SDF_CMD_WRITE) &&
write_subdevice->async) {
max_buffer_size_kb = write_subdevice->async->max_bufsize /
bytes_per_kibi;
}
retval = snprintf(buf, PAGE_SIZE, "%i\n", max_buffer_size_kb);
mutex_unlock(&info->device->mutex);
return retval;
}
static ssize_t store_max_write_buffer_kb(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct comedi_device_file_info *info = dev_get_drvdata(dev);
unsigned int new_max_size_kb;
unsigned int new_max_size;
int ret;
struct comedi_subdevice *const write_subdevice =
comedi_get_write_subdevice(info);
ret = kstrtouint(buf, 10, &new_max_size_kb);
if (ret)
return ret;
if (new_max_size_kb > (UINT_MAX / bytes_per_kibi))
return -EINVAL;
new_max_size = new_max_size_kb * bytes_per_kibi;
mutex_lock(&info->device->mutex);
if (write_subdevice == NULL ||
(write_subdevice->subdev_flags & SDF_CMD_WRITE) == 0 ||
write_subdevice->async == NULL) {
mutex_unlock(&info->device->mutex);
return -EINVAL;
}
write_subdevice->async->max_bufsize = new_max_size;
mutex_unlock(&info->device->mutex);
return count;
}
static struct device_attribute dev_attr_max_write_buffer_kb = {
.attr = {
.name = "max_write_buffer_kb",
.mode = S_IRUGO | S_IWUSR},
.show = &show_max_write_buffer_kb,
.store = &store_max_write_buffer_kb
};
static ssize_t show_write_buffer_kb(struct device *dev,
struct device_attribute *attr, char *buf)
{
ssize_t retval;
struct comedi_device_file_info *info = dev_get_drvdata(dev);
unsigned buffer_size_kb = 0;
struct comedi_subdevice *const write_subdevice =
comedi_get_write_subdevice(info);
mutex_lock(&info->device->mutex);
if (write_subdevice &&
(write_subdevice->subdev_flags & SDF_CMD_WRITE) &&
write_subdevice->async) {
buffer_size_kb = write_subdevice->async->prealloc_bufsz /
bytes_per_kibi;
}
retval = snprintf(buf, PAGE_SIZE, "%i\n", buffer_size_kb);
mutex_unlock(&info->device->mutex);
return retval;
}
static ssize_t store_write_buffer_kb(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct comedi_device_file_info *info = dev_get_drvdata(dev);
unsigned int new_size_kb;
unsigned int new_size;
int retval;
int ret;
struct comedi_subdevice *const write_subdevice =
comedi_get_write_subdevice(info);
ret = kstrtouint(buf, 10, &new_size_kb);
if (ret)
return ret;
if (new_size_kb > (UINT_MAX / bytes_per_kibi))
return -EINVAL;
new_size = ((uint64_t) new_size_kb) * bytes_per_kibi;
mutex_lock(&info->device->mutex);
if (write_subdevice == NULL ||
(write_subdevice->subdev_flags & SDF_CMD_WRITE) == 0 ||
write_subdevice->async == NULL) {
mutex_unlock(&info->device->mutex);
return -EINVAL;
}
retval = resize_async_buffer(info->device, write_subdevice,
write_subdevice->async, new_size);
mutex_unlock(&info->device->mutex);
if (retval < 0)
return retval;
return count;
}
static struct device_attribute dev_attr_write_buffer_kb = {
.attr = {
.name = "write_buffer_kb",
.mode = S_IRUGO | S_IWUSR | S_IWGRP},
.show = &show_write_buffer_kb,
.store = &store_write_buffer_kb
};