drivers/staging/comedi/comedi_fops.c

   1 /*
   2     comedi/comedi_fops.c
   3     comedi kernel module
   4
   5     COMEDI - Linux Control and Measurement Device Interface
   6     Copyright (C) 1997-2000 David A. Schleef <[email protected]>
   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 #undef DEBUG
  25
  26 #define __NO_VERSION__
  27 #include "comedi_fops.h"
  28 #include "comedi_compat32.h"
  29
  30 #include <linux/module.h>
  31 #include <linux/errno.h>
  32 #include <linux/kernel.h>
  33 #include <linux/sched.h>
  34 #include <linux/fcntl.h>
  35 #include <linux/delay.h>
  36 #include <linux/ioport.h>
  37 #include <linux/mm.h>
  38 #include <linux/slab.h>
  39 #include <linux/kmod.h>
  40 #include <linux/poll.h>
  41 #include <linux/init.h>
  42 #include <linux/device.h>
  43 #include <linux/vmalloc.h>
  44 #include <linux/fs.h>
  45 #include "comedidev.h"
  46 #include <linux/cdev.h>
  47 #include <linux/stat.h>
  48
  49 #include <linux/io.h>
  50 #include <linux/uaccess.h>
  51
  52 #include "internal.h"
  53
  54 MODULE_AUTHOR("http://www.comedi.org");
  55 MODULE_DESCRIPTION("Comedi core module");
  56 MODULE_LICENSE("GPL");
  57
  58 #ifdef CONFIG_COMEDI_DEBUG
  59 int comedi_debug;
  60 EXPORT_SYMBOL(comedi_debug);
  61 module_param(comedi_debug, int, 0644);
  62 #endif
  63
  64 int comedi_autoconfig = 1;
  65 module_param(comedi_autoconfig, bool, 0444);
  66
  67 static int comedi_num_legacy_minors;
  68 module_param(comedi_num_legacy_minors, int, 0444);
  69
  70 static DEFINE_SPINLOCK(comedi_file_info_table_lock);
  71 static struct comedi_device_file_info
  72 *comedi_file_info_table[COMEDI_NUM_MINORS];
  73
  74 static int do_devconfig_ioctl(struct comedi_device *dev,
  75                               struct comedi_devconfig __user *arg);
  76 static int do_bufconfig_ioctl(struct comedi_device *dev,
  77                               struct comedi_bufconfig __user *arg);
  78 static int do_devinfo_ioctl(struct comedi_device *dev,
  79                             struct comedi_devinfo __user *arg,
  80                             struct file *file);
  81 static int do_subdinfo_ioctl(struct comedi_device *dev,
  82                              struct comedi_subdinfo __user *arg, void *file);
  83 static int do_chaninfo_ioctl(struct comedi_device *dev,
  84                              struct comedi_chaninfo __user *arg);
  85 static int do_bufinfo_ioctl(struct comedi_device *dev,
  86                             struct comedi_bufinfo __user *arg, void *file);
  87 static int do_cmd_ioctl(struct comedi_device *dev,
  88                         struct comedi_cmd __user *arg, void *file);
  89 static int do_lock_ioctl(struct comedi_device *dev, unsigned int arg,
  90                          void *file);
  91 static int do_unlock_ioctl(struct comedi_device *dev, unsigned int arg,
  92                            void *file);
  93 static int do_cancel_ioctl(struct comedi_device *dev, unsigned int arg,
  94                            void *file);
  95 static int do_cmdtest_ioctl(struct comedi_device *dev,
  96                             struct comedi_cmd __user *arg, void *file);
  97 static int do_insnlist_ioctl(struct comedi_device *dev,
  98                              struct comedi_insnlist __user *arg, void *file);
  99 static int do_insn_ioctl(struct comedi_device *dev,
 100                          struct comedi_insn __user *arg, void *file);
 101 static int do_poll_ioctl(struct comedi_device *dev, unsigned int subd,
 102                          void *file);
 103
 104 extern void do_become_nonbusy(struct comedi_device *dev,
 105                               struct comedi_subdevice *s);
 106 static int do_cancel(struct comedi_device *dev, struct comedi_subdevice *s);
 107
 108 static int comedi_fasync(int fd, struct file *file, int on);
 109
 110 static int is_device_busy(struct comedi_device *dev);
 111 static int resize_async_buffer(struct comedi_device *dev,
 112                                struct comedi_subdevice *s,
 113                                struct comedi_async *async, unsigned new_size);
 114
 115 /* declarations for sysfs attribute files */
 116 static struct device_attribute dev_attr_max_read_buffer_kb;
 117 static struct device_attribute dev_attr_read_buffer_kb;
 118 static struct device_attribute dev_attr_max_write_buffer_kb;
 119 static struct device_attribute dev_attr_write_buffer_kb;
 120
 121 static long comedi_unlocked_ioctl(struct file *file, unsigned int cmd,
 122                                   unsigned long arg)
 123 {
 124         const unsigned minor = iminor(file->f_dentry->d_inode);
 125         struct comedi_device_file_info *dev_file_info =
 126             comedi_get_device_file_info(minor);
 127         struct comedi_device *dev;
 128         int rc;
 129
 130         if (dev_file_info == NULL || dev_file_info->device == NULL)
 131                 return -ENODEV;
 132         dev = dev_file_info->device;
 133
 134         mutex_lock(&dev->mutex);
 135
 136         /* Device config is special, because it must work on
 137          * an unconfigured device. */
 138         if (cmd == COMEDI_DEVCONFIG) {
 139                 rc = do_devconfig_ioctl(dev,
 140                                         (struct comedi_devconfig __user *)arg);
 141                 goto done;
 142         }
 143
 144         if (!dev->attached) {
 145                 DPRINTK("no driver configured on /dev/comedi%i\n", dev->minor);
 146                 rc = -ENODEV;
 147                 goto done;
 148         }
 149
 150         switch (cmd) {
 151         case COMEDI_BUFCONFIG:
 152                 rc = do_bufconfig_ioctl(dev,
 153                                         (struct comedi_bufconfig __user *)arg);
 154                 break;
 155         case COMEDI_DEVINFO:
 156                 rc = do_devinfo_ioctl(dev, (struct comedi_devinfo __user *)arg,
 157                                       file);
 158                 break;
 159         case COMEDI_SUBDINFO:
 160                 rc = do_subdinfo_ioctl(dev,
 161                                        (struct comedi_subdinfo __user *)arg,
 162                                        file);
 163                 break;
 164         case COMEDI_CHANINFO:
 165                 rc = do_chaninfo_ioctl(dev, (void __user *)arg);
 166                 break;
 167         case COMEDI_RANGEINFO:
 168                 rc = do_rangeinfo_ioctl(dev, (void __user *)arg);
 169                 break;
 170         case COMEDI_BUFINFO:
 171                 rc = do_bufinfo_ioctl(dev,
 172                                       (struct comedi_bufinfo __user *)arg,
 173                                       file);
 174                 break;
 175         case COMEDI_LOCK:
 176                 rc = do_lock_ioctl(dev, arg, file);
 177                 break;
 178         case COMEDI_UNLOCK:
 179                 rc = do_unlock_ioctl(dev, arg, file);
 180                 break;
 181         case COMEDI_CANCEL:
 182                 rc = do_cancel_ioctl(dev, arg, file);
 183                 break;
 184         case COMEDI_CMD:
 185                 rc = do_cmd_ioctl(dev, (struct comedi_cmd __user *)arg, file);
 186                 break;
 187         case COMEDI_CMDTEST:
 188                 rc = do_cmdtest_ioctl(dev, (struct comedi_cmd __user *)arg,
 189                                       file);
 190                 break;
 191         case COMEDI_INSNLIST:
 192                 rc = do_insnlist_ioctl(dev,
 193                                        (struct comedi_insnlist __user *)arg,
 194                                        file);
 195                 break;
 196         case COMEDI_INSN:
 197                 rc = do_insn_ioctl(dev, (struct comedi_insn __user *)arg,
 198                                    file);
 199                 break;
 200         case COMEDI_POLL:
 201                 rc = do_poll_ioctl(dev, arg, file);
 202                 break;
 203         default:
 204                 rc = -ENOTTY;
 205                 break;
 206         }
 207
 208 done:
 209         mutex_unlock(&dev->mutex);
 210         return rc;
 211 }
 212
 213 /*
 214         COMEDI_DEVCONFIG
 215         device config ioctl
 216
 217         arg:
 218                 pointer to devconfig structure
 219
 220         reads:
 221                 devconfig structure at arg
 222
 223         writes:
 224                 none
 225 */
 226 static int do_devconfig_ioctl(struct comedi_device *dev,
 227                               struct comedi_devconfig __user *arg)
 228 {
 229         struct comedi_devconfig it;
 230         int ret;
 231         unsigned char *aux_data = NULL;
 232         int aux_len;
 233
 234         if (!capable(CAP_SYS_ADMIN))
 235                 return -EPERM;
 236
 237         if (arg == NULL) {
 238                 if (is_device_busy(dev))
 239                         return -EBUSY;
 240                 if (dev->attached) {
 241                         struct module *driver_module = dev->driver->module;
 242                         comedi_device_detach(dev);
 243                         module_put(driver_module);
 244                 }
 245                 return 0;
 246         }
 247
 248         if (copy_from_user(&it, arg, sizeof(struct comedi_devconfig)))
 249                 return -EFAULT;
 250
 251         it.board_name[COMEDI_NAMELEN - 1] = 0;
 252
 253         if (comedi_aux_data(it.options, 0) &&
 254             it.options[COMEDI_DEVCONF_AUX_DATA_LENGTH]) {
 255                 int bit_shift;
 256                 aux_len = it.options[COMEDI_DEVCONF_AUX_DATA_LENGTH];
 257                 if (aux_len < 0)
 258                         return -EFAULT;
 259
 260                 aux_data = vmalloc(aux_len);
 261                 if (!aux_data)
 262                         return -ENOMEM;
 263
 264                 if (copy_from_user(aux_data,
 265                                    comedi_aux_data(it.options, 0), aux_len)) {
 266                         vfree(aux_data);
 267                         return -EFAULT;
 268                 }
 269                 it.options[COMEDI_DEVCONF_AUX_DATA_LO] =
 270                     (unsigned long)aux_data;
 271                 if (sizeof(void *) > sizeof(int)) {
 272                         bit_shift = sizeof(int) * 8;
 273                         it.options[COMEDI_DEVCONF_AUX_DATA_HI] =
 274                             ((unsigned long)aux_data) >> bit_shift;
 275                 } else
 276                         it.options[COMEDI_DEVCONF_AUX_DATA_HI] = 0;
 277         }
 278
 279         ret = comedi_device_attach(dev, &it);
 280         if (ret == 0) {
 281                 if (!try_module_get(dev->driver->module)) {
 282                         comedi_device_detach(dev);
 283                         return -ENOSYS;
 284                 }
 285         }
 286
 287         if (aux_data)
 288                 vfree(aux_data);
 289
 290         return ret;
 291 }
 292
 293 /*
 294         COMEDI_BUFCONFIG
 295         buffer configuration ioctl
 296
 297         arg:
 298                 pointer to bufconfig structure
 299
 300         reads:
 301                 bufconfig at arg
 302
 303         writes:
 304                 modified bufconfig at arg
 305
 306 */
 307 static int do_bufconfig_ioctl(struct comedi_device *dev,
 308                               struct comedi_bufconfig __user *arg)
 309 {
 310         struct comedi_bufconfig bc;
 311         struct comedi_async *async;
 312         struct comedi_subdevice *s;
 313         int retval = 0;
 314
 315         if (copy_from_user(&bc, arg, sizeof(struct comedi_bufconfig)))
 316                 return -EFAULT;
 317
 318         if (bc.subdevice >= dev->n_subdevices || bc.subdevice < 0)
 319                 return -EINVAL;
 320
 321         s = dev->subdevices + bc.subdevice;
 322         async = s->async;
 323
 324         if (!async) {
 325                 DPRINTK("subdevice does not have async capability\n");
 326                 bc.size = 0;
 327                 bc.maximum_size = 0;
 328                 goto copyback;
 329         }
 330
 331         if (bc.maximum_size) {
 332                 if (!capable(CAP_SYS_ADMIN))
 333                         return -EPERM;
 334
 335                 async->max_bufsize = bc.maximum_size;
 336         }
 337
 338         if (bc.size) {
 339                 retval = resize_async_buffer(dev, s, async, bc.size);
 340                 if (retval < 0)
 341                         return retval;
 342         }
 343
 344         bc.size = async->prealloc_bufsz;
 345         bc.maximum_size = async->max_bufsize;
 346
 347 copyback:
 348         if (copy_to_user(arg, &bc, sizeof(struct comedi_bufconfig)))
 349                 return -EFAULT;
 350
 351         return 0;
 352 }
 353
 354 /*
 355         COMEDI_DEVINFO
 356         device info ioctl
 357
 358         arg:
 359                 pointer to devinfo structure
 360
 361         reads:
 362                 none
 363
 364         writes:
 365                 devinfo structure
 366
 367 */
 368 static int do_devinfo_ioctl(struct comedi_device *dev,
 369                             struct comedi_devinfo __user *arg,
 370                             struct file *file)
 371 {
 372         struct comedi_devinfo devinfo;
 373         const unsigned minor = iminor(file->f_dentry->d_inode);
 374         struct comedi_device_file_info *dev_file_info =
 375             comedi_get_device_file_info(minor);
 376         struct comedi_subdevice *read_subdev =
 377             comedi_get_read_subdevice(dev_file_info);
 378         struct comedi_subdevice *write_subdev =
 379             comedi_get_write_subdevice(dev_file_info);
 380
 381         memset(&devinfo, 0, sizeof(devinfo));
 382
 383         /* fill devinfo structure */
 384         devinfo.version_code = COMEDI_VERSION_CODE;
 385         devinfo.n_subdevs = dev->n_subdevices;
 386         memcpy(devinfo.driver_name, dev->driver->driver_name, COMEDI_NAMELEN);
 387         memcpy(devinfo.board_name, dev->board_name, COMEDI_NAMELEN);
 388
 389         if (read_subdev)
 390                 devinfo.read_subdevice = read_subdev - dev->subdevices;
 391         else
 392                 devinfo.read_subdevice = -1;
 393
 394         if (write_subdev)
 395                 devinfo.write_subdevice = write_subdev - dev->subdevices;
 396         else
 397                 devinfo.write_subdevice = -1;
 398
 399         if (copy_to_user(arg, &devinfo, sizeof(struct comedi_devinfo)))
 400                 return -EFAULT;
 401
 402         return 0;
 403 }
 404
 405 /*
 406         COMEDI_SUBDINFO
 407         subdevice info ioctl
 408
 409         arg:
 410                 pointer to array of subdevice info structures
 411
 412         reads:
 413                 none
 414
 415         writes:
 416                 array of subdevice info structures at arg
 417
 418 */
 419 static int do_subdinfo_ioctl(struct comedi_device *dev,
 420                              struct comedi_subdinfo __user *arg, void *file)
 421 {
 422         int ret, i;
 423         struct comedi_subdinfo *tmp, *us;
 424         struct comedi_subdevice *s;
 425
 426         tmp =
 427             kcalloc(dev->n_subdevices, sizeof(struct comedi_subdinfo),
 428                     GFP_KERNEL);
 429         if (!tmp)
 430                 return -ENOMEM;
 431
 432         /* fill subdinfo structs */
 433         for (i = 0; i < dev->n_subdevices; i++) {
 434                 s = dev->subdevices + i;
 435                 us = tmp + i;
 436
 437                 us->type = s->type;
 438                 us->n_chan = s->n_chan;
 439                 us->subd_flags = s->subdev_flags;
 440                 if (comedi_get_subdevice_runflags(s) & SRF_RUNNING)
 441                         us->subd_flags |= SDF_RUNNING;
 442 #define TIMER_nanosec 5         /* backwards compatibility */
 443                 us->timer_type = TIMER_nanosec;
 444                 us->len_chanlist = s->len_chanlist;
 445                 us->maxdata = s->maxdata;
 446                 if (s->range_table) {
 447                         us->range_type =
 448                             (i << 24) | (0 << 16) | (s->range_table->length);
 449                 } else {
 450                         us->range_type = 0;     /* XXX */
 451                 }
 452                 us->flags = s->flags;
 453
 454                 if (s->busy)
 455                         us->subd_flags |= SDF_BUSY;
 456                 if (s->busy == file)
 457                         us->subd_flags |= SDF_BUSY_OWNER;
 458                 if (s->lock)
 459                         us->subd_flags |= SDF_LOCKED;
 460                 if (s->lock == file)
 461                         us->subd_flags |= SDF_LOCK_OWNER;
 462                 if (!s->maxdata && s->maxdata_list)
 463                         us->subd_flags |= SDF_MAXDATA;
 464                 if (s->flaglist)
 465                         us->subd_flags |= SDF_FLAGS;
 466                 if (s->range_table_list)
 467                         us->subd_flags |= SDF_RANGETYPE;
 468                 if (s->do_cmd)
 469                         us->subd_flags |= SDF_CMD;
 470
 471                 if (s->insn_bits != &insn_inval)
 472                         us->insn_bits_support = COMEDI_SUPPORTED;
 473                 else
 474                         us->insn_bits_support = COMEDI_UNSUPPORTED;
 475
 476                 us->settling_time_0 = s->settling_time_0;
 477         }
 478
 479         ret = copy_to_user(arg, tmp,
 480                            dev->n_subdevices * sizeof(struct comedi_subdinfo));
 481
 482         kfree(tmp);
 483
 484         return ret ? -EFAULT : 0;
 485 }
 486
 487 /*
 488         COMEDI_CHANINFO
 489         subdevice info ioctl
 490
 491         arg:
 492                 pointer to chaninfo structure
 493
 494         reads:
 495                 chaninfo structure at arg
 496
 497         writes:
 498                 arrays at elements of chaninfo structure
 499
 500 */
 501 static int do_chaninfo_ioctl(struct comedi_device *dev,
 502                              struct comedi_chaninfo __user *arg)
 503 {
 504         struct comedi_subdevice *s;
 505         struct comedi_chaninfo it;
 506
 507         if (copy_from_user(&it, arg, sizeof(struct comedi_chaninfo)))
 508                 return -EFAULT;
 509
 510         if (it.subdev >= dev->n_subdevices)
 511                 return -EINVAL;
 512         s = dev->subdevices + it.subdev;
 513
 514         if (it.maxdata_list) {
 515                 if (s->maxdata || !s->maxdata_list)
 516                         return -EINVAL;
 517                 if (copy_to_user(it.maxdata_list, s->maxdata_list,
 518                                  s->n_chan * sizeof(unsigned int)))
 519                         return -EFAULT;
 520         }
 521
 522         if (it.flaglist) {
 523                 if (!s->flaglist)
 524                         return -EINVAL;
 525                 if (copy_to_user(it.flaglist, s->flaglist,
 526                                  s->n_chan * sizeof(unsigned int)))
 527                         return -EFAULT;
 528         }
 529
 530         if (it.rangelist) {
 531                 int i;
 532
 533                 if (!s->range_table_list)
 534                         return -EINVAL;
 535                 for (i = 0; i < s->n_chan; i++) {
 536                         int x;
 537
 538                         x = (dev->minor << 28) | (it.subdev << 24) | (i << 16) |
 539                             (s->range_table_list[i]->length);
 540                         if (put_user(x, it.rangelist + i))
 541                                 return -EFAULT;
 542                 }
 543 #if 0
 544                 if (copy_to_user(it.rangelist, s->range_type_list,
 545                                  s->n_chan * sizeof(unsigned int)))
 546                         return -EFAULT;
 547 #endif
 548         }
 549
 550         return 0;
 551 }
 552
 553  /*
 554     COMEDI_BUFINFO
 555     buffer information ioctl
 556
 557     arg:
 558     pointer to bufinfo structure
 559
 560     reads:
 561     bufinfo at arg
 562
 563     writes:
 564     modified bufinfo at arg
 565
 566   */
 567 static int do_bufinfo_ioctl(struct comedi_device *dev,
 568                             struct comedi_bufinfo __user *arg, void *file)
 569 {
 570         struct comedi_bufinfo bi;
 571         struct comedi_subdevice *s;
 572         struct comedi_async *async;
 573
 574         if (copy_from_user(&bi, arg, sizeof(struct comedi_bufinfo)))
 575                 return -EFAULT;
 576
 577         if (bi.subdevice >= dev->n_subdevices || bi.subdevice < 0)
 578                 return -EINVAL;
 579
 580         s = dev->subdevices + bi.subdevice;
 581
 582         if (s->lock && s->lock != file)
 583                 return -EACCES;
 584
 585         async = s->async;
 586
 587         if (!async) {
 588                 DPRINTK("subdevice does not have async capability\n");
 589                 bi.buf_write_ptr = 0;
 590                 bi.buf_read_ptr = 0;
 591                 bi.buf_write_count = 0;
 592                 bi.buf_read_count = 0;
 593                 bi.bytes_read = 0;
 594                 bi.bytes_written = 0;
 595                 goto copyback;
 596         }
 597         if (!s->busy) {
 598                 bi.bytes_read = 0;
 599                 bi.bytes_written = 0;
 600                 goto copyback_position;
 601         }
 602         if (s->busy != file)
 603                 return -EACCES;
 604
 605         if (bi.bytes_read && (s->subdev_flags & SDF_CMD_READ)) {
 606                 bi.bytes_read = comedi_buf_read_alloc(async, bi.bytes_read);
 607                 comedi_buf_read_free(async, bi.bytes_read);
 608
 609                 if (!(comedi_get_subdevice_runflags(s) & (SRF_ERROR |
 610                                                           SRF_RUNNING))
 611                     && async->buf_write_count == async->buf_read_count) {
 612                         do_become_nonbusy(dev, s);
 613                 }
 614         }
 615
 616         if (bi.bytes_written && (s->subdev_flags & SDF_CMD_WRITE)) {
 617                 bi.bytes_written =
 618                     comedi_buf_write_alloc(async, bi.bytes_written);
 619                 comedi_buf_write_free(async, bi.bytes_written);
 620         }
 621
 622 copyback_position:
 623         bi.buf_write_count = async->buf_write_count;
 624         bi.buf_write_ptr = async->buf_write_ptr;
 625         bi.buf_read_count = async->buf_read_count;
 626         bi.buf_read_ptr = async->buf_read_ptr;
 627
 628 copyback:
 629         if (copy_to_user(arg, &bi, sizeof(struct comedi_bufinfo)))
 630                 return -EFAULT;
 631
 632         return 0;
 633 }
 634
 635 static int parse_insn(struct comedi_device *dev, struct comedi_insn *insn,
 636                       unsigned int *data, void *file);
 637 /*
 638  *      COMEDI_INSNLIST
 639  *      synchronous instructions
 640  *
 641  *      arg:
 642  *              pointer to sync cmd structure
 643  *
 644  *      reads:
 645  *              sync cmd struct at arg
 646  *              instruction list
 647  *              data (for writes)
 648  *
 649  *      writes:
 650  *              data (for reads)
 651  */
 652 /* arbitrary limits */
 653 #define MAX_SAMPLES 256
 654 static int do_insnlist_ioctl(struct comedi_device *dev,
 655                              struct comedi_insnlist __user *arg, void *file)
 656 {
 657         struct comedi_insnlist insnlist;
 658         struct comedi_insn *insns = NULL;
 659         unsigned int *data = NULL;
 660         int i = 0;
 661         int ret = 0;
 662
 663         if (copy_from_user(&insnlist, arg, sizeof(struct comedi_insnlist)))
 664                 return -EFAULT;
 665
 666         data = kmalloc(sizeof(unsigned int) * MAX_SAMPLES, GFP_KERNEL);
 667         if (!data) {
 668                 DPRINTK("kmalloc failed\n");
 669                 ret = -ENOMEM;
 670                 goto error;
 671         }
 672
 673         insns =
 674             kmalloc(sizeof(struct comedi_insn) * insnlist.n_insns, GFP_KERNEL);
 675         if (!insns) {
 676                 DPRINTK("kmalloc failed\n");
 677                 ret = -ENOMEM;
 678                 goto error;
 679         }
 680
 681         if (copy_from_user(insns, insnlist.insns,
 682                            sizeof(struct comedi_insn) * insnlist.n_insns)) {
 683                 DPRINTK("copy_from_user failed\n");
 684                 ret = -EFAULT;
 685                 goto error;
 686         }
 687
 688         for (i = 0; i < insnlist.n_insns; i++) {
 689                 if (insns[i].n > MAX_SAMPLES) {
 690                         DPRINTK("number of samples too large\n");
 691                         ret = -EINVAL;
 692                         goto error;
 693                 }
 694                 if (insns[i].insn & INSN_MASK_WRITE) {
 695                         if (copy_from_user(data, insns[i].data,
 696                                            insns[i].n * sizeof(unsigned int))) {
 697                                 DPRINTK("copy_from_user failed\n");
 698                                 ret = -EFAULT;
 699                                 goto error;
 700                         }
 701                 }
 702                 ret = parse_insn(dev, insns + i, data, file);
 703                 if (ret < 0)
 704                         goto error;
 705                 if (insns[i].insn & INSN_MASK_READ) {
 706                         if (copy_to_user(insns[i].data, data,
 707                                          insns[i].n * sizeof(unsigned int))) {
 708                                 DPRINTK("copy_to_user failed\n");
 709                                 ret = -EFAULT;
 710                                 goto error;
 711                         }
 712                 }
 713                 if (need_resched())
 714                         schedule();
 715         }
 716
 717 error:
 718         kfree(insns);
 719         kfree(data);
 720
 721         if (ret < 0)
 722                 return ret;
 723         return i;
 724 }
 725
 726 static int check_insn_config_length(struct comedi_insn *insn,
 727                                     unsigned int *data)
 728 {
 729         if (insn->n < 1)
 730                 return -EINVAL;
 731
 732         switch (data[0]) {
 733         case INSN_CONFIG_DIO_OUTPUT:
 734         case INSN_CONFIG_DIO_INPUT:
 735         case INSN_CONFIG_DISARM:
 736         case INSN_CONFIG_RESET:
 737                 if (insn->n == 1)
 738                         return 0;
 739                 break;
 740         case INSN_CONFIG_ARM:
 741         case INSN_CONFIG_DIO_QUERY:
 742         case INSN_CONFIG_BLOCK_SIZE:
 743         case INSN_CONFIG_FILTER:
 744         case INSN_CONFIG_SERIAL_CLOCK:
 745         case INSN_CONFIG_BIDIRECTIONAL_DATA:
 746         case INSN_CONFIG_ALT_SOURCE:
 747         case INSN_CONFIG_SET_COUNTER_MODE:
 748         case INSN_CONFIG_8254_READ_STATUS:
 749         case INSN_CONFIG_SET_ROUTING:
 750         case INSN_CONFIG_GET_ROUTING:
 751         case INSN_CONFIG_GET_PWM_STATUS:
 752         case INSN_CONFIG_PWM_SET_PERIOD:
 753         case INSN_CONFIG_PWM_GET_PERIOD:
 754                 if (insn->n == 2)
 755                         return 0;
 756                 break;
 757         case INSN_CONFIG_SET_GATE_SRC:
 758         case INSN_CONFIG_GET_GATE_SRC:
 759         case INSN_CONFIG_SET_CLOCK_SRC:
 760         case INSN_CONFIG_GET_CLOCK_SRC:
 761         case INSN_CONFIG_SET_OTHER_SRC:
 762         case INSN_CONFIG_GET_COUNTER_STATUS:
 763         case INSN_CONFIG_PWM_SET_H_BRIDGE:
 764         case INSN_CONFIG_PWM_GET_H_BRIDGE:
 765         case INSN_CONFIG_GET_HARDWARE_BUFFER_SIZE:
 766                 if (insn->n == 3)
 767                         return 0;
 768                 break;
 769         case INSN_CONFIG_PWM_OUTPUT:
 770         case INSN_CONFIG_ANALOG_TRIG:
 771                 if (insn->n == 5)
 772                         return 0;
 773                 break;
 774                 /* by default we allow the insn since we don't have checks for
 775                  * all possible cases yet */
 776         default:
 777                 printk(KERN_WARNING
 778                        "comedi: no check for data length of config insn id "
 779                        "%i is implemented.\n"
 780                        " Add a check to %s in %s.\n"
 781                        " Assuming n=%i is correct.\n", data[0], __func__,
 782                        __FILE__, insn->n);
 783                 return 0;
 784                 break;
 785         }
 786         return -EINVAL;
 787 }
 788
 789 static int parse_insn(struct comedi_device *dev, struct comedi_insn *insn,
 790                       unsigned int *data, void *file)
 791 {
 792         struct comedi_subdevice *s;
 793         int ret = 0;
 794         int i;
 795
 796         if (insn->insn & INSN_MASK_SPECIAL) {
 797                 /* a non-subdevice instruction */
 798
 799                 switch (insn->insn) {
 800                 case INSN_GTOD:
 801                         {
 802                                 struct timeval tv;
 803
 804                                 if (insn->n != 2) {
 805                                         ret = -EINVAL;
 806                                         break;
 807                                 }
 808
 809                                 do_gettimeofday(&tv);
 810                                 data[0] = tv.tv_sec;
 811                                 data[1] = tv.tv_usec;
 812                                 ret = 2;
 813
 814                                 break;
 815                         }
 816                 case INSN_WAIT:
 817                         if (insn->n != 1 || data[0] >= 100000) {
 818                                 ret = -EINVAL;
 819                                 break;
 820                         }
 821                         udelay(data[0] / 1000);
 822                         ret = 1;
 823                         break;
 824                 case INSN_INTTRIG:
 825                         if (insn->n != 1) {
 826                                 ret = -EINVAL;
 827                                 break;
 828                         }
 829                         if (insn->subdev >= dev->n_subdevices) {
 830                                 DPRINTK("%d not usable subdevice\n",
 831                                         insn->subdev);
 832                                 ret = -EINVAL;
 833                                 break;
 834                         }
 835                         s = dev->subdevices + insn->subdev;
 836                         if (!s->async) {
 837                                 DPRINTK("no async\n");
 838                                 ret = -EINVAL;
 839                                 break;
 840                         }
 841                         if (!s->async->inttrig) {
 842                                 DPRINTK("no inttrig\n");
 843                                 ret = -EAGAIN;
 844                                 break;
 845                         }
 846                         ret = s->async->inttrig(dev, s, insn->data[0]);
 847                         if (ret >= 0)
 848                                 ret = 1;
 849                         break;
 850                 default:
 851                         DPRINTK("invalid insn\n");
 852                         ret = -EINVAL;
 853                         break;
 854                 }
 855         } else {
 856                 /* a subdevice instruction */
 857                 unsigned int maxdata;
 858
 859                 if (insn->subdev >= dev->n_subdevices) {
 860                         DPRINTK("subdevice %d out of range\n", insn->subdev);
 861                         ret = -EINVAL;
 862                         goto out;
 863                 }
 864                 s = dev->subdevices + insn->subdev;
 865
 866                 if (s->type == COMEDI_SUBD_UNUSED) {
 867                         DPRINTK("%d not usable subdevice\n", insn->subdev);
 868                         ret = -EIO;
 869                         goto out;
 870                 }
 871
 872                 /* are we locked? (ioctl lock) */
 873                 if (s->lock && s->lock != file) {
 874                         DPRINTK("device locked\n");
 875                         ret = -EACCES;
 876                         goto out;
 877                 }
 878
 879                 ret = comedi_check_chanlist(s, 1, &insn->chanspec);
 880                 if (ret < 0) {
 881                         ret = -EINVAL;
 882                         DPRINTK("bad chanspec\n");
 883                         goto out;
 884                 }
 885
 886                 if (s->busy) {
 887                         ret = -EBUSY;
 888                         goto out;
 889                 }
 890                 /* This looks arbitrary.  It is. */
 891                 s->busy = &parse_insn;
 892                 switch (insn->insn) {
 893                 case INSN_READ:
 894                         ret = s->insn_read(dev, s, insn, data);
 895                         break;
 896                 case INSN_WRITE:
 897                         maxdata = s->maxdata_list
 898                             ? s->maxdata_list[CR_CHAN(insn->chanspec)]
 899                             : s->maxdata;
 900                         for (i = 0; i < insn->n; ++i) {
 901                                 if (data[i] > maxdata) {
 902                                         ret = -EINVAL;
 903                                         DPRINTK("bad data value(s)\n");
 904                                         break;
 905                                 }
 906                         }
 907                         if (ret == 0)
 908                                 ret = s->insn_write(dev, s, insn, data);
 909                         break;
 910                 case INSN_BITS:
 911                         if (insn->n != 2) {
 912                                 ret = -EINVAL;
 913                                 break;
 914                         }
 915                         ret = s->insn_bits(dev, s, insn, data);
 916                         break;
 917                 case INSN_CONFIG:
 918                         ret = check_insn_config_length(insn, data);
 919                         if (ret)
 920                                 break;
 921                         ret = s->insn_config(dev, s, insn, data);
 922                         break;
 923                 default:
 924                         ret = -EINVAL;
 925                         break;
 926                 }
 927
 928                 s->busy = NULL;
 929         }
 930
 931 out:
 932         return ret;
 933 }
 934
 935 /*
 936  *      COMEDI_INSN
 937  *      synchronous instructions
 938  *
 939  *      arg:
 940  *              pointer to insn
 941  *
 942  *      reads:
 943  *              struct comedi_insn struct at arg
 944  *              data (for writes)
 945  *
 946  *      writes:
 947  *              data (for reads)
 948  */
 949 static int do_insn_ioctl(struct comedi_device *dev,
 950                          struct comedi_insn __user *arg, void *file)
 951 {
 952         struct comedi_insn insn;
 953         unsigned int *data = NULL;
 954         int ret = 0;
 955
 956         data = kmalloc(sizeof(unsigned int) * MAX_SAMPLES, GFP_KERNEL);
 957         if (!data) {
 958                 ret = -ENOMEM;
 959                 goto error;
 960         }
 961
 962         if (copy_from_user(&insn, arg, sizeof(struct comedi_insn))) {
 963                 ret = -EFAULT;
 964                 goto error;
 965         }
 966
 967         /* This is where the behavior of insn and insnlist deviate. */
 968         if (insn.n > MAX_SAMPLES)
 969                 insn.n = MAX_SAMPLES;
 970         if (insn.insn & INSN_MASK_WRITE) {
 971                 if (copy_from_user(data,
 972                                    insn.data,
 973                                    insn.n * sizeof(unsigned int))) {
 974                         ret = -EFAULT;
 975                         goto error;
 976                 }
 977         }
 978         ret = parse_insn(dev, &insn, data, file);
 979         if (ret < 0)
 980                 goto error;
 981         if (insn.insn & INSN_MASK_READ) {
 982                 if (copy_to_user(insn.data,
 983                                  data,
 984                                  insn.n * sizeof(unsigned int))) {
 985                         ret = -EFAULT;
 986                         goto error;
 987                 }
 988         }
 989         ret = insn.n;
 990
 991 error:
 992         kfree(data);
 993
 994         return ret;
 995 }
 996
 997 static void comedi_set_subdevice_runflags(struct comedi_subdevice *s,
 998                                           unsigned mask, unsigned bits)
 999 {
1000         unsigned long flags;
1001
1002         spin_lock_irqsave(&s->spin_lock, flags);
1003         s->runflags &= ~mask;
1004         s->runflags |= (bits & mask);
1005         spin_unlock_irqrestore(&s->spin_lock, flags);
1006 }
1007
1008 static int do_cmd_ioctl(struct comedi_device *dev,
1009                         struct comedi_cmd __user *cmd, void *file)
1010 {
1011         struct comedi_cmd user_cmd;
1012         struct comedi_subdevice *s;
1013         struct comedi_async *async;
1014         int ret = 0;
1015         unsigned int __user *chanlist_saver = NULL;
1016
1017         if (copy_from_user(&user_cmd, cmd, sizeof(struct comedi_cmd))) {
1018                 DPRINTK("bad cmd address\n");
1019                 return -EFAULT;
1020         }
1021         /* save user's chanlist pointer so it can be restored later */
1022         chanlist_saver = user_cmd.chanlist;
1023
1024         if (user_cmd.subdev >= dev->n_subdevices) {
1025                 DPRINTK("%d no such subdevice\n", user_cmd.subdev);
1026                 return -ENODEV;
1027         }
1028
1029         s = dev->subdevices + user_cmd.subdev;
1030         async = s->async;
1031
1032         if (s->type == COMEDI_SUBD_UNUSED) {
1033                 DPRINTK("%d not valid subdevice\n", user_cmd.subdev);
1034                 return -EIO;
1035         }
1036
1037         if (!s->do_cmd || !s->do_cmdtest || !s->async) {
1038                 DPRINTK("subdevice %i does not support commands\n",
1039                         user_cmd.subdev);
1040                 return -EIO;
1041         }
1042
1043         /* are we locked? (ioctl lock) */
1044         if (s->lock && s->lock != file) {
1045                 DPRINTK("subdevice locked\n");
1046                 return -EACCES;
1047         }
1048
1049         /* are we busy? */
1050         if (s->busy) {
1051                 DPRINTK("subdevice busy\n");
1052                 return -EBUSY;
1053         }
1054         s->busy = file;
1055
1056         /* make sure channel/gain list isn't too long */
1057         if (user_cmd.chanlist_len > s->len_chanlist) {
1058                 DPRINTK("channel/gain list too long %u > %d\n",
1059                         user_cmd.chanlist_len, s->len_chanlist);
1060                 ret = -EINVAL;
1061                 goto cleanup;
1062         }
1063
1064         /* make sure channel/gain list isn't too short */
1065         if (user_cmd.chanlist_len < 1) {
1066                 DPRINTK("channel/gain list too short %u < 1\n",
1067                         user_cmd.chanlist_len);
1068                 ret = -EINVAL;
1069                 goto cleanup;
1070         }
1071
1072         kfree(async->cmd.chanlist);
1073         async->cmd = user_cmd;
1074         async->cmd.data = NULL;
1075         /* load channel/gain list */
1076         async->cmd.chanlist =
1077             kmalloc(async->cmd.chanlist_len * sizeof(int), GFP_KERNEL);
1078         if (!async->cmd.chanlist) {
1079                 DPRINTK("allocation failed\n");
1080                 ret = -ENOMEM;
1081                 goto cleanup;
1082         }
1083
1084         if (copy_from_user(async->cmd.chanlist, user_cmd.chanlist,
1085                            async->cmd.chanlist_len * sizeof(int))) {
1086                 DPRINTK("fault reading chanlist\n");
1087                 ret = -EFAULT;
1088                 goto cleanup;
1089         }
1090
1091         /* make sure each element in channel/gain list is valid */
1092         ret = comedi_check_chanlist(s,
1093                                     async->cmd.chanlist_len,
1094                                     async->cmd.chanlist);
1095         if (ret < 0) {
1096                 DPRINTK("bad chanlist\n");
1097                 goto cleanup;
1098         }
1099
1100         ret = s->do_cmdtest(dev, s, &async->cmd);
1101
1102         if (async->cmd.flags & TRIG_BOGUS || ret) {
1103                 DPRINTK("test returned %d\n", ret);
1104                 user_cmd = async->cmd;
1105                 /* restore chanlist pointer before copying back */
1106                 user_cmd.chanlist = chanlist_saver;
1107                 user_cmd.data = NULL;
1108                 if (copy_to_user(cmd, &user_cmd, sizeof(struct comedi_cmd))) {
1109                         DPRINTK("fault writing cmd\n");
1110                         ret = -EFAULT;
1111                         goto cleanup;
1112                 }
1113                 ret = -EAGAIN;
1114                 goto cleanup;
1115         }
1116
1117         if (!async->prealloc_bufsz) {
1118                 ret = -ENOMEM;
1119                 DPRINTK("no buffer (?)\n");
1120                 goto cleanup;
1121         }
1122
1123         comedi_reset_async_buf(async);
1124
1125         async->cb_mask =
1126             COMEDI_CB_EOA | COMEDI_CB_BLOCK | COMEDI_CB_ERROR |
1127             COMEDI_CB_OVERFLOW;
1128         if (async->cmd.flags & TRIG_WAKE_EOS)
1129                 async->cb_mask |= COMEDI_CB_EOS;
1130
1131         comedi_set_subdevice_runflags(s, ~0, SRF_USER | SRF_RUNNING);
1132
1133         ret = s->do_cmd(dev, s);
1134         if (ret == 0)
1135                 return 0;
1136
1137 cleanup:
1138         do_become_nonbusy(dev, s);
1139
1140         return ret;
1141 }
1142
1143 /*
1144         COMEDI_CMDTEST
1145         command testing ioctl
1146
1147         arg:
1148                 pointer to cmd structure
1149
1150         reads:
1151                 cmd structure at arg
1152                 channel/range list
1153
1154         writes:
1155                 modified cmd structure at arg
1156
1157 */
1158 static int do_cmdtest_ioctl(struct comedi_device *dev,
1159                             struct comedi_cmd __user *arg, void *file)
1160 {
1161         struct comedi_cmd user_cmd;
1162         struct comedi_subdevice *s;
1163         int ret = 0;
1164         unsigned int *chanlist = NULL;
1165         unsigned int __user *chanlist_saver = NULL;
1166
1167         if (copy_from_user(&user_cmd, arg, sizeof(struct comedi_cmd))) {
1168                 DPRINTK("bad cmd address\n");
1169                 return -EFAULT;
1170         }
1171         /* save user's chanlist pointer so it can be restored later */
1172         chanlist_saver = user_cmd.chanlist;
1173
1174         if (user_cmd.subdev >= dev->n_subdevices) {
1175                 DPRINTK("%d no such subdevice\n", user_cmd.subdev);
1176                 return -ENODEV;
1177         }
1178
1179         s = dev->subdevices + user_cmd.subdev;
1180         if (s->type == COMEDI_SUBD_UNUSED) {
1181                 DPRINTK("%d not valid subdevice\n", user_cmd.subdev);
1182                 return -EIO;
1183         }
1184
1185         if (!s->do_cmd || !s->do_cmdtest) {
1186                 DPRINTK("subdevice %i does not support commands\n",
1187                         user_cmd.subdev);
1188                 return -EIO;
1189         }
1190
1191         /* make sure channel/gain list isn't too long */
1192         if (user_cmd.chanlist_len > s->len_chanlist) {
1193                 DPRINTK("channel/gain list too long %d > %d\n",
1194                         user_cmd.chanlist_len, s->len_chanlist);
1195                 ret = -EINVAL;
1196                 goto cleanup;
1197         }
1198
1199         /* load channel/gain list */
1200         if (user_cmd.chanlist) {
1201                 chanlist =
1202                     kmalloc(user_cmd.chanlist_len * sizeof(int), GFP_KERNEL);
1203                 if (!chanlist) {
1204                         DPRINTK("allocation failed\n");
1205                         ret = -ENOMEM;
1206                         goto cleanup;
1207                 }
1208
1209                 if (copy_from_user(chanlist, user_cmd.chanlist,
1210                                    user_cmd.chanlist_len * sizeof(int))) {
1211                         DPRINTK("fault reading chanlist\n");
1212                         ret = -EFAULT;
1213                         goto cleanup;
1214                 }
1215
1216                 /* make sure each element in channel/gain list is valid */
1217                 ret = comedi_check_chanlist(s, user_cmd.chanlist_len, chanlist);
1218                 if (ret < 0) {
1219                         DPRINTK("bad chanlist\n");
1220                         goto cleanup;
1221                 }
1222
1223                 user_cmd.chanlist = chanlist;
1224         }
1225
1226         ret = s->do_cmdtest(dev, s, &user_cmd);
1227
1228         /* restore chanlist pointer before copying back */
1229         user_cmd.chanlist = chanlist_saver;
1230
1231         if (copy_to_user(arg, &user_cmd, sizeof(struct comedi_cmd))) {
1232                 DPRINTK("bad cmd address\n");
1233                 ret = -EFAULT;
1234                 goto cleanup;
1235         }
1236 cleanup:
1237         kfree(chanlist);
1238
1239         return ret;
1240 }
1241
1242 /*
1243         COMEDI_LOCK
1244         lock subdevice
1245
1246         arg:
1247                 subdevice number
1248
1249         reads:
1250                 none
1251
1252         writes:
1253                 none
1254
1255 */
1256
1257 static int do_lock_ioctl(struct comedi_device *dev, unsigned int arg,
1258                          void *file)
1259 {
1260         int ret = 0;
1261         unsigned long flags;
1262         struct comedi_subdevice *s;
1263
1264         if (arg >= dev->n_subdevices)
1265                 return -EINVAL;
1266         s = dev->subdevices + arg;
1267
1268         spin_lock_irqsave(&s->spin_lock, flags);
1269         if (s->busy || s->lock)
1270                 ret = -EBUSY;
1271         else
1272                 s->lock = file;
1273         spin_unlock_irqrestore(&s->spin_lock, flags);
1274
1275         if (ret < 0)
1276                 return ret;
1277
1278 #if 0
1279         if (s->lock_f)
1280                 ret = s->lock_f(dev, s);
1281 #endif
1282
1283         return ret;
1284 }
1285
1286 /*
1287         COMEDI_UNLOCK
1288         unlock subdevice
1289
1290         arg:
1291                 subdevice number
1292
1293         reads:
1294                 none
1295
1296         writes:
1297                 none
1298
1299         This function isn't protected by the semaphore, since
1300         we already own the lock.
1301 */
1302 static int do_unlock_ioctl(struct comedi_device *dev, unsigned int arg,
1303                            void *file)
1304 {
1305         struct comedi_subdevice *s;
1306
1307         if (arg >= dev->n_subdevices)
1308                 return -EINVAL;
1309         s = dev->subdevices + arg;
1310
1311         if (s->busy)
1312                 return -EBUSY;
1313
1314         if (s->lock && s->lock != file)
1315                 return -EACCES;
1316
1317         if (s->lock == file) {
1318 #if 0
1319                 if (s->unlock)
1320                         s->unlock(dev, s);
1321 #endif
1322
1323                 s->lock = NULL;
1324         }
1325
1326         return 0;
1327 }
1328
1329 /*
1330         COMEDI_CANCEL
1331         cancel acquisition ioctl
1332
1333         arg:
1334                 subdevice number
1335
1336         reads:
1337                 nothing
1338
1339         writes:
1340                 nothing
1341
1342 */
1343 static int do_cancel_ioctl(struct comedi_device *dev, unsigned int arg,
1344                            void *file)
1345 {
1346         struct comedi_subdevice *s;
1347
1348         if (arg >= dev->n_subdevices)
1349                 return -EINVAL;
1350         s = dev->subdevices + arg;
1351         if (s->async == NULL)
1352                 return -EINVAL;
1353
1354         if (s->lock && s->lock != file)
1355                 return -EACCES;
1356
1357         if (!s->busy)
1358                 return 0;
1359
1360         if (s->busy != file)
1361                 return -EBUSY;
1362
1363         return do_cancel(dev, s);
1364 }
1365
1366 /*
1367         COMEDI_POLL ioctl
1368         instructs driver to synchronize buffers
1369
1370         arg:
1371                 subdevice number
1372
1373         reads:
1374                 nothing
1375
1376         writes:
1377                 nothing
1378
1379 */
1380 static int do_poll_ioctl(struct comedi_device *dev, unsigned int arg,
1381                          void *file)
1382 {
1383         struct comedi_subdevice *s;
1384
1385         if (arg >= dev->n_subdevices)
1386                 return -EINVAL;
1387         s = dev->subdevices + arg;
1388
1389         if (s->lock && s->lock != file)
1390                 return -EACCES;
1391
1392         if (!s->busy)
1393                 return 0;
1394
1395         if (s->busy != file)
1396                 return -EBUSY;
1397
1398         if (s->poll)
1399                 return s->poll(dev, s);
1400
1401         return -EINVAL;
1402 }
1403
1404 static int do_cancel(struct comedi_device *dev, struct comedi_subdevice *s)
1405 {
1406         int ret = 0;
1407
1408         if ((comedi_get_subdevice_runflags(s) & SRF_RUNNING) && s->cancel)
1409                 ret = s->cancel(dev, s);
1410
1411         do_become_nonbusy(dev, s);
1412
1413         return ret;
1414 }
1415
1416 static void comedi_unmap(struct vm_area_struct *area)
1417 {
1418         struct comedi_async *async;
1419         struct comedi_device *dev;
1420
1421         async = area->vm_private_data;
1422         dev = async->subdevice->device;
1423
1424         mutex_lock(&dev->mutex);
1425         async->mmap_count--;
1426         mutex_unlock(&dev->mutex);
1427 }
1428
1429 static struct vm_operations_struct comedi_vm_ops = {
1430         .close = comedi_unmap,
1431 };
1432
1433 static int comedi_mmap(struct file *file, struct vm_area_struct *vma)
1434 {
1435         const unsigned minor = iminor(file->f_dentry->d_inode);
1436         struct comedi_device_file_info *dev_file_info =
1437             comedi_get_device_file_info(minor);
1438         struct comedi_device *dev = dev_file_info->device;
1439         struct comedi_async *async = NULL;
1440         unsigned long start = vma->vm_start;
1441         unsigned long size;
1442         int n_pages;
1443         int i;
1444         int retval;
1445         struct comedi_subdevice *s;
1446
1447         mutex_lock(&dev->mutex);
1448         if (!dev->attached) {
1449                 DPRINTK("no driver configured on comedi%i\n", dev->minor);
1450                 retval = -ENODEV;
1451                 goto done;
1452         }
1453         if (vma->vm_flags & VM_WRITE)
1454                 s = comedi_get_write_subdevice(dev_file_info);
1455         else
1456                 s = comedi_get_read_subdevice(dev_file_info);
1457
1458         if (s == NULL) {
1459                 retval = -EINVAL;
1460                 goto done;
1461         }
1462         async = s->async;
1463         if (async == NULL) {
1464                 retval = -EINVAL;
1465                 goto done;
1466         }
1467
1468         if (vma->vm_pgoff != 0) {
1469                 DPRINTK("comedi: mmap() offset must be 0.\n");
1470                 retval = -EINVAL;
1471                 goto done;
1472         }
1473
1474         size = vma->vm_end - vma->vm_start;
1475         if (size > async->prealloc_bufsz) {
1476                 retval = -EFAULT;
1477                 goto done;
1478         }
1479         if (size & (~PAGE_MASK)) {
1480                 retval = -EFAULT;
1481                 goto done;
1482         }
1483
1484         n_pages = size >> PAGE_SHIFT;
1485         for (i = 0; i < n_pages; ++i) {
1486                 if (remap_pfn_range(vma, start,
1487                                     page_to_pfn(virt_to_page
1488                                                 (async->buf_page_list
1489                                                  [i].virt_addr)), PAGE_SIZE,
1490                                     PAGE_SHARED)) {
1491                         retval = -EAGAIN;
1492                         goto done;
1493                 }
1494                 start += PAGE_SIZE;
1495         }
1496
1497         vma->vm_ops = &comedi_vm_ops;
1498         vma->vm_private_data = async;
1499
1500         async->mmap_count++;
1501
1502         retval = 0;
1503 done:
1504         mutex_unlock(&dev->mutex);
1505         return retval;
1506 }
1507
1508 static unsigned int comedi_poll(struct file *file, poll_table * wait)
1509 {
1510         unsigned int mask = 0;
1511         const unsigned minor = iminor(file->f_dentry->d_inode);
1512         struct comedi_device_file_info *dev_file_info =
1513             comedi_get_device_file_info(minor);
1514         struct comedi_device *dev = dev_file_info->device;
1515         struct comedi_subdevice *read_subdev;
1516         struct comedi_subdevice *write_subdev;
1517
1518         mutex_lock(&dev->mutex);
1519         if (!dev->attached) {
1520                 DPRINTK("no driver configured on comedi%i\n", dev->minor);
1521                 mutex_unlock(&dev->mutex);
1522                 return 0;
1523         }
1524
1525         mask = 0;
1526         read_subdev = comedi_get_read_subdevice(dev_file_info);
1527         if (read_subdev) {
1528                 poll_wait(file, &read_subdev->async->wait_head, wait);
1529                 if (!read_subdev->busy
1530                     || comedi_buf_read_n_available(read_subdev->async) > 0
1531                     || !(comedi_get_subdevice_runflags(read_subdev) &
1532                          SRF_RUNNING)) {
1533                         mask |= POLLIN | POLLRDNORM;
1534                 }
1535         }
1536         write_subdev = comedi_get_write_subdevice(dev_file_info);
1537         if (write_subdev) {
1538                 poll_wait(file, &write_subdev->async->wait_head, wait);
1539                 comedi_buf_write_alloc(write_subdev->async,
1540                                        write_subdev->async->prealloc_bufsz);
1541                 if (!write_subdev->busy
1542                     || !(comedi_get_subdevice_runflags(write_subdev) &
1543                          SRF_RUNNING)
1544                     || comedi_buf_write_n_allocated(write_subdev->async) >=
1545                     bytes_per_sample(write_subdev->async->subdevice)) {
1546                         mask |= POLLOUT | POLLWRNORM;
1547                 }
1548         }
1549
1550         mutex_unlock(&dev->mutex);
1551         return mask;
1552 }
1553
1554 static ssize_t comedi_write(struct file *file, const char __user *buf,
1555                             size_t nbytes, loff_t *offset)
1556 {
1557         struct comedi_subdevice *s;
1558         struct comedi_async *async;
1559         int n, m, count = 0, retval = 0;
1560         DECLARE_WAITQUEUE(wait, current);
1561         const unsigned minor = iminor(file->f_dentry->d_inode);
1562         struct comedi_device_file_info *dev_file_info =
1563             comedi_get_device_file_info(minor);
1564         struct comedi_device *dev = dev_file_info->device;
1565
1566         if (!dev->attached) {
1567                 DPRINTK("no driver configured on comedi%i\n", dev->minor);
1568                 retval = -ENODEV;
1569                 goto done;
1570         }
1571
1572         s = comedi_get_write_subdevice(dev_file_info);
1573         if (s == NULL) {
1574                 retval = -EIO;
1575                 goto done;
1576         }
1577         async = s->async;
1578
1579         if (!nbytes) {
1580                 retval = 0;
1581                 goto done;
1582         }
1583         if (!s->busy) {
1584                 retval = 0;
1585                 goto done;
1586         }
1587         if (s->busy != file) {
1588                 retval = -EACCES;
1589                 goto done;
1590         }
1591         add_wait_queue(&async->wait_head, &wait);
1592         while (nbytes > 0 && !retval) {
1593                 set_current_state(TASK_INTERRUPTIBLE);
1594
1595                 if (!(comedi_get_subdevice_runflags(s) & SRF_RUNNING)) {
1596                         if (count == 0) {
1597                                 if (comedi_get_subdevice_runflags(s) &
1598                                         SRF_ERROR) {
1599                                         retval = -EPIPE;
1600                                 } else {
1601                                         retval = 0;
1602                                 }
1603                                 do_become_nonbusy(dev, s);
1604                         }
1605                         break;
1606                 }
1607
1608                 n = nbytes;
1609
1610                 m = n;
1611                 if (async->buf_write_ptr + m > async->prealloc_bufsz)
1612                         m = async->prealloc_bufsz - async->buf_write_ptr;
1613                 comedi_buf_write_alloc(async, async->prealloc_bufsz);
1614                 if (m > comedi_buf_write_n_allocated(async))
1615                         m = comedi_buf_write_n_allocated(async);
1616                 if (m < n)
1617                         n = m;
1618
1619                 if (n == 0) {
1620                         if (file->f_flags & O_NONBLOCK) {
1621                                 retval = -EAGAIN;
1622                                 break;
1623                         }
1624                         if (signal_pending(current)) {
1625                                 retval = -ERESTARTSYS;
1626                                 break;
1627                         }
1628                         schedule();
1629                         if (!s->busy)
1630                                 break;
1631                         if (s->busy != file) {
1632                                 retval = -EACCES;
1633                                 break;
1634                         }
1635                         continue;
1636                 }
1637
1638                 m = copy_from_user(async->prealloc_buf + async->buf_write_ptr,
1639                                    buf, n);
1640                 if (m) {
1641                         n -= m;
1642                         retval = -EFAULT;
1643                 }
1644                 comedi_buf_write_free(async, n);
1645
1646                 count += n;
1647                 nbytes -= n;
1648
1649                 buf += n;
1650                 break;          /* makes device work like a pipe */
1651         }
1652         set_current_state(TASK_RUNNING);
1653         remove_wait_queue(&async->wait_head, &wait);
1654
1655 done:
1656         return count ? count : retval;
1657 }
1658
1659 static ssize_t comedi_read(struct file *file, char __user *buf, size_t nbytes,
1660                                 loff_t *offset)
1661 {
1662         struct comedi_subdevice *s;
1663         struct comedi_async *async;
1664         int n, m, count = 0, retval = 0;
1665         DECLARE_WAITQUEUE(wait, current);
1666         const unsigned minor = iminor(file->f_dentry->d_inode);
1667         struct comedi_device_file_info *dev_file_info =
1668             comedi_get_device_file_info(minor);
1669         struct comedi_device *dev = dev_file_info->device;
1670
1671         if (!dev->attached) {
1672                 DPRINTK("no driver configured on comedi%i\n", dev->minor);
1673                 retval = -ENODEV;
1674                 goto done;
1675         }
1676
1677         s = comedi_get_read_subdevice(dev_file_info);
1678         if (s == NULL) {
1679                 retval = -EIO;
1680                 goto done;
1681         }
1682         async = s->async;
1683         if (!nbytes) {
1684                 retval = 0;
1685                 goto done;
1686         }
1687         if (!s->busy) {
1688                 retval = 0;
1689                 goto done;
1690         }
1691         if (s->busy != file) {
1692                 retval = -EACCES;
1693                 goto done;
1694         }
1695
1696         add_wait_queue(&async->wait_head, &wait);
1697         while (nbytes > 0 && !retval) {
1698                 set_current_state(TASK_INTERRUPTIBLE);
1699
1700                 n = nbytes;
1701
1702                 m = comedi_buf_read_n_available(async);
1703                 /* printk("%d available\n",m); */
1704                 if (async->buf_read_ptr + m > async->prealloc_bufsz)
1705                         m = async->prealloc_bufsz - async->buf_read_ptr;
1706                 /* printk("%d contiguous\n",m); */
1707                 if (m < n)
1708                         n = m;
1709
1710                 if (n == 0) {
1711                         if (!(comedi_get_subdevice_runflags(s) & SRF_RUNNING)) {
1712                                 do_become_nonbusy(dev, s);
1713                                 if (comedi_get_subdevice_runflags(s) &
1714                                     SRF_ERROR) {
1715                                         retval = -EPIPE;
1716                                 } else {
1717                                         retval = 0;
1718                                 }
1719                                 break;
1720                         }
1721                         if (file->f_flags & O_NONBLOCK) {
1722                                 retval = -EAGAIN;
1723                                 break;
1724                         }
1725                         if (signal_pending(current)) {
1726                                 retval = -ERESTARTSYS;
1727                                 break;
1728                         }
1729                         schedule();
1730                         if (!s->busy) {
1731                                 retval = 0;
1732                                 break;
1733                         }
1734                         if (s->busy != file) {
1735                                 retval = -EACCES;
1736                                 break;
1737                         }
1738                         continue;
1739                 }
1740                 m = copy_to_user(buf, async->prealloc_buf +
1741                                  async->buf_read_ptr, n);
1742                 if (m) {
1743                         n -= m;
1744                         retval = -EFAULT;
1745                 }
1746
1747                 comedi_buf_read_alloc(async, n);
1748                 comedi_buf_read_free(async, n);
1749
1750                 count += n;
1751                 nbytes -= n;
1752
1753                 buf += n;
1754                 break;          /* makes device work like a pipe */
1755         }
1756         if (!(comedi_get_subdevice_runflags(s) & (SRF_ERROR | SRF_RUNNING)) &&
1757             async->buf_read_count - async->buf_write_count == 0) {
1758                 do_become_nonbusy(dev, s);
1759         }
1760         set_current_state(TASK_RUNNING);
1761         remove_wait_queue(&async->wait_head, &wait);
1762
1763 done:
1764         return count ? count : retval;
1765 }
1766
1767 /*
1768    This function restores a subdevice to an idle state.
1769  */
1770 void do_become_nonbusy(struct comedi_device *dev, struct comedi_subdevice *s)
1771 {
1772         struct comedi_async *async = s->async;
1773
1774         comedi_set_subdevice_runflags(s, SRF_RUNNING, 0);
1775         if (async) {
1776                 comedi_reset_async_buf(async);
1777                 async->inttrig = NULL;
1778         } else {
1779                 printk(KERN_ERR
1780                        "BUG: (?) do_become_nonbusy called with async=0\n");
1781         }
1782
1783         s->busy = NULL;
1784 }
1785
1786 static int comedi_open(struct inode *inode, struct file *file)
1787 {
1788         const unsigned minor = iminor(inode);
1789         struct comedi_device_file_info *dev_file_info =
1790             comedi_get_device_file_info(minor);
1791         struct comedi_device *dev =
1792             dev_file_info ? dev_file_info->device : NULL;
1793
1794         if (dev == NULL) {
1795                 DPRINTK("invalid minor number\n");
1796                 return -ENODEV;
1797         }
1798
1799         /* This is slightly hacky, but we want module autoloading
1800          * to work for root.
1801          * case: user opens device, attached -> ok
1802          * case: user opens device, unattached, in_request_module=0 -> autoload
1803          * case: user opens device, unattached, in_request_module=1 -> fail
1804          * case: root opens device, attached -> ok
1805          * case: root opens device, unattached, in_request_module=1 -> ok
1806          *   (typically called from modprobe)
1807          * case: root opens device, unattached, in_request_module=0 -> autoload
1808          *
1809          * The last could be changed to "-> ok", which would deny root
1810          * autoloading.
1811          */
1812         mutex_lock(&dev->mutex);
1813         if (dev->attached)
1814                 goto ok;
1815         if (!capable(CAP_NET_ADMIN) && dev->in_request_module) {
1816                 DPRINTK("in request module\n");
1817                 mutex_unlock(&dev->mutex);
1818                 return -ENODEV;
1819         }
1820         if (capable(CAP_NET_ADMIN) && dev->in_request_module)
1821                 goto ok;
1822
1823         dev->in_request_module = 1;
1824
1825 #ifdef CONFIG_KMOD
1826         mutex_unlock(&dev->mutex);
1827         request_module("char-major-%i-%i", COMEDI_MAJOR, dev->minor);
1828         mutex_lock(&dev->mutex);
1829 #endif
1830
1831         dev->in_request_module = 0;
1832
1833         if (!dev->attached && !capable(CAP_NET_ADMIN)) {
1834                 DPRINTK("not attached and not CAP_NET_ADMIN\n");
1835                 mutex_unlock(&dev->mutex);
1836                 return -ENODEV;
1837         }
1838 ok:
1839         __module_get(THIS_MODULE);
1840
1841         if (dev->attached) {
1842                 if (!try_module_get(dev->driver->module)) {
1843                         module_put(THIS_MODULE);
1844                         mutex_unlock(&dev->mutex);
1845                         return -ENOSYS;
1846                 }
1847         }
1848
1849         if (dev->attached && dev->use_count == 0 && dev->open) {
1850                 int rc = dev->open(dev);
1851                 if (rc < 0) {
1852                         module_put(dev->driver->module);
1853                         module_put(THIS_MODULE);
1854                         mutex_unlock(&dev->mutex);
1855                         return rc;
1856                 }
1857         }
1858
1859         dev->use_count++;
1860
1861         mutex_unlock(&dev->mutex);
1862
1863         return 0;
1864 }
1865
1866 static int comedi_close(struct inode *inode, struct file *file)
1867 {
1868         const unsigned minor = iminor(inode);
1869         struct comedi_device_file_info *dev_file_info =
1870             comedi_get_device_file_info(minor);
1871         struct comedi_device *dev = dev_file_info->device;
1872         struct comedi_subdevice *s = NULL;
1873         int i;
1874
1875         mutex_lock(&dev->mutex);
1876
1877         if (dev->subdevices) {
1878                 for (i = 0; i < dev->n_subdevices; i++) {
1879                         s = dev->subdevices + i;
1880
1881                         if (s->busy == file)
1882                                 do_cancel(dev, s);
1883                         if (s->lock == file)
1884                                 s->lock = NULL;
1885                 }
1886         }
1887         if (dev->attached && dev->use_count == 1 && dev->close)
1888                 dev->close(dev);
1889
1890         module_put(THIS_MODULE);
1891         if (dev->attached)
1892                 module_put(dev->driver->module);
1893
1894         dev->use_count--;
1895
1896         mutex_unlock(&dev->mutex);
1897
1898         if (file->f_flags & FASYNC)
1899                 comedi_fasync(-1, file, 0);
1900
1901         return 0;
1902 }
1903
1904 static int comedi_fasync(int fd, struct file *file, int on)
1905 {
1906         const unsigned minor = iminor(file->f_dentry->d_inode);
1907         struct comedi_device_file_info *dev_file_info =
1908             comedi_get_device_file_info(minor);
1909
1910         struct comedi_device *dev = dev_file_info->device;
1911
1912         return fasync_helper(fd, file, on, &dev->async_queue);
1913 }
1914
1915 const struct file_operations comedi_fops = {
1916         .owner = THIS_MODULE,
1917         .unlocked_ioctl = comedi_unlocked_ioctl,
1918         .compat_ioctl = comedi_compat_ioctl,
1919         .open = comedi_open,
1920         .release = comedi_close,
1921         .read = comedi_read,
1922         .write = comedi_write,
1923         .mmap = comedi_mmap,
1924         .poll = comedi_poll,
1925         .fasync = comedi_fasync,
1926         .llseek = noop_llseek,
1927 };
1928
1929 struct class *comedi_class;
1930 static struct cdev comedi_cdev;
1931
1932 static void comedi_cleanup_legacy_minors(void)
1933 {
1934         unsigned i;
1935
1936         for (i = 0; i < comedi_num_legacy_minors; i++)
1937                 comedi_free_board_minor(i);
1938 }
1939
1940 static int __init comedi_init(void)
1941 {
1942         int i;
1943         int retval;
1944
1945         printk(KERN_INFO "comedi: version " COMEDI_RELEASE
1946                " - http://www.comedi.org\n");
1947
1948         if (comedi_num_legacy_minors < 0 ||
1949             comedi_num_legacy_minors > COMEDI_NUM_BOARD_MINORS) {
1950                 printk(KERN_ERR "comedi: error: invalid value for module "
1951                        "parameter \"comedi_num_legacy_minors\".  Valid values "
1952                        "are 0 through %i.\n", COMEDI_NUM_BOARD_MINORS);
1953                 return -EINVAL;
1954         }
1955
1956         /*
1957          * comedi is unusable if both comedi_autoconfig and
1958          * comedi_num_legacy_minors are zero, so we might as well adjust the
1959          * defaults in that case
1960          */
1961         if (comedi_autoconfig == 0 && comedi_num_legacy_minors == 0)
1962                 comedi_num_legacy_minors = 16;
1963
1964         memset(comedi_file_info_table, 0,
1965                sizeof(struct comedi_device_file_info *) * COMEDI_NUM_MINORS);
1966
1967         retval = register_chrdev_region(MKDEV(COMEDI_MAJOR, 0),
1968                                         COMEDI_NUM_MINORS, "comedi");
1969         if (retval)
1970                 return -EIO;
1971         cdev_init(&comedi_cdev, &comedi_fops);
1972         comedi_cdev.owner = THIS_MODULE;
1973         kobject_set_name(&comedi_cdev.kobj, "comedi");
1974         if (cdev_add(&comedi_cdev, MKDEV(COMEDI_MAJOR, 0), COMEDI_NUM_MINORS)) {
1975                 unregister_chrdev_region(MKDEV(COMEDI_MAJOR, 0),
1976                                          COMEDI_NUM_MINORS);
1977                 return -EIO;
1978         }
1979         comedi_class = class_create(THIS_MODULE, "comedi");
1980         if (IS_ERR(comedi_class)) {
1981                 printk(KERN_ERR "comedi: failed to create class");
1982                 cdev_del(&comedi_cdev);
1983                 unregister_chrdev_region(MKDEV(COMEDI_MAJOR, 0),
1984                                          COMEDI_NUM_MINORS);
1985                 return PTR_ERR(comedi_class);
1986         }
1987
1988         /* XXX requires /proc interface */
1989         comedi_proc_init();
1990
1991         /* create devices files for legacy/manual use */
1992         for (i = 0; i < comedi_num_legacy_minors; i++) {
1993                 int minor;
1994                 minor = comedi_alloc_board_minor(NULL);
1995                 if (minor < 0) {
1996                         comedi_cleanup_legacy_minors();
1997                         cdev_del(&comedi_cdev);
1998                         unregister_chrdev_region(MKDEV(COMEDI_MAJOR, 0),
1999                                                  COMEDI_NUM_MINORS);
2000                         return minor;
2001                 }
2002         }
2003
2004         return 0;
2005 }
2006
2007 static void __exit comedi_cleanup(void)
2008 {
2009         int i;
2010
2011         comedi_cleanup_legacy_minors();
2012         for (i = 0; i < COMEDI_NUM_MINORS; ++i)
2013                 BUG_ON(comedi_file_info_table[i]);
2014
2015         class_destroy(comedi_class);
2016         cdev_del(&comedi_cdev);
2017         unregister_chrdev_region(MKDEV(COMEDI_MAJOR, 0), COMEDI_NUM_MINORS);
2018
2019         comedi_proc_cleanup();
2020 }
2021
2022 module_init(comedi_init);
2023 module_exit(comedi_cleanup);
2024
2025 void comedi_error(const struct comedi_device *dev, const char *s)
2026 {
2027         printk(KERN_ERR "comedi%d: %s: %s\n", dev->minor,
2028                dev->driver->driver_name, s);
2029 }
2030 EXPORT_SYMBOL(comedi_error);
2031
2032 void comedi_event(struct comedi_device *dev, struct comedi_subdevice *s)
2033 {
2034         struct comedi_async *async = s->async;
2035         unsigned runflags = 0;
2036         unsigned runflags_mask = 0;
2037
2038         /* DPRINTK("comedi_event 0x%x\n",mask); */
2039
2040         if ((comedi_get_subdevice_runflags(s) & SRF_RUNNING) == 0)
2041                 return;
2042
2043         if (s->
2044             async->events & (COMEDI_CB_EOA | COMEDI_CB_ERROR |
2045                              COMEDI_CB_OVERFLOW)) {
2046                 runflags_mask |= SRF_RUNNING;
2047         }
2048         /* remember if an error event has occured, so an error
2049          * can be returned the next time the user does a read() */
2050         if (s->async->events & (COMEDI_CB_ERROR | COMEDI_CB_OVERFLOW)) {
2051                 runflags_mask |= SRF_ERROR;
2052                 runflags |= SRF_ERROR;
2053         }
2054         if (runflags_mask) {
2055                 /*sets SRF_ERROR and SRF_RUNNING together atomically */
2056                 comedi_set_subdevice_runflags(s, runflags_mask, runflags);
2057         }
2058
2059         if (async->cb_mask & s->async->events) {
2060                 if (comedi_get_subdevice_runflags(s) & SRF_USER) {
2061                         wake_up_interruptible(&async->wait_head);
2062                         if (s->subdev_flags & SDF_CMD_READ)
2063                                 kill_fasync(&dev->async_queue, SIGIO, POLL_IN);
2064                         if (s->subdev_flags & SDF_CMD_WRITE)
2065                                 kill_fasync(&dev->async_queue, SIGIO, POLL_OUT);
2066                 } else {
2067                         if (async->cb_func)
2068                                 async->cb_func(s->async->events, async->cb_arg);
2069                 }
2070         }
2071         s->async->events = 0;
2072 }
2073 EXPORT_SYMBOL(comedi_event);
2074
2075 unsigned comedi_get_subdevice_runflags(struct comedi_subdevice *s)
2076 {
2077         unsigned long flags;
2078         unsigned runflags;
2079
2080         spin_lock_irqsave(&s->spin_lock, flags);
2081         runflags = s->runflags;
2082         spin_unlock_irqrestore(&s->spin_lock, flags);
2083         return runflags;
2084 }
2085 EXPORT_SYMBOL(comedi_get_subdevice_runflags);
2086
2087 static int is_device_busy(struct comedi_device *dev)
2088 {
2089         struct comedi_subdevice *s;
2090         int i;
2091
2092         if (!dev->attached)
2093                 return 0;
2094
2095         for (i = 0; i < dev->n_subdevices; i++) {
2096                 s = dev->subdevices + i;
2097                 if (s->busy)
2098                         return 1;
2099                 if (s->async && s->async->mmap_count)
2100                         return 1;
2101         }
2102
2103         return 0;
2104 }
2105
2106 static void comedi_device_init(struct comedi_device *dev)
2107 {
2108         memset(dev, 0, sizeof(struct comedi_device));
2109         spin_lock_init(&dev->spinlock);
2110         mutex_init(&dev->mutex);
2111         dev->minor = -1;
2112 }
2113
2114 static void comedi_device_cleanup(struct comedi_device *dev)
2115 {
2116         if (dev == NULL)
2117                 return;
2118         mutex_lock(&dev->mutex);
2119         comedi_device_detach(dev);
2120         mutex_unlock(&dev->mutex);
2121         mutex_destroy(&dev->mutex);
2122 }
2123
2124 int comedi_alloc_board_minor(struct device *hardware_device)
2125 {
2126         unsigned long flags;
2127         struct comedi_device_file_info *info;
2128         struct device *csdev;
2129         unsigned i;
2130         int retval;
2131
2132         info = kzalloc(sizeof(struct comedi_device_file_info), GFP_KERNEL);
2133         if (info == NULL)
2134                 return -ENOMEM;
2135         info->device = kzalloc(sizeof(struct comedi_device), GFP_KERNEL);
2136         if (info->device == NULL) {
2137                 kfree(info);
2138                 return -ENOMEM;
2139         }
2140         comedi_device_init(info->device);
2141         spin_lock_irqsave(&comedi_file_info_table_lock, flags);
2142         for (i = 0; i < COMEDI_NUM_BOARD_MINORS; ++i) {
2143                 if (comedi_file_info_table[i] == NULL) {
2144                         comedi_file_info_table[i] = info;
2145                         break;
2146                 }
2147         }
2148         spin_unlock_irqrestore(&comedi_file_info_table_lock, flags);
2149         if (i == COMEDI_NUM_BOARD_MINORS) {
2150                 comedi_device_cleanup(info->device);
2151                 kfree(info->device);
2152                 kfree(info);
2153                 printk(KERN_ERR
2154                        "comedi: error: "
2155                        "ran out of minor numbers for board device files.\n");
2156                 return -EBUSY;
2157         }
2158         info->device->minor = i;
2159         csdev = COMEDI_DEVICE_CREATE(comedi_class, NULL,
2160                                      MKDEV(COMEDI_MAJOR, i), NULL,
2161                                      hardware_device, "comedi%i", i);
2162         if (!IS_ERR(csdev))
2163                 info->device->class_dev = csdev;
2164         dev_set_drvdata(csdev, info);
2165         retval = device_create_file(csdev, &dev_attr_max_read_buffer_kb);
2166         if (retval) {
2167                 printk(KERN_ERR
2168                        "comedi: "
2169                        "failed to create sysfs attribute file \"%s\".\n",
2170                        dev_attr_max_read_buffer_kb.attr.name);
2171                 comedi_free_board_minor(i);
2172                 return retval;
2173         }
2174         retval = device_create_file(csdev, &dev_attr_read_buffer_kb);
2175         if (retval) {
2176                 printk(KERN_ERR
2177                        "comedi: "
2178                        "failed to create sysfs attribute file \"%s\".\n",
2179                        dev_attr_read_buffer_kb.attr.name);
2180                 comedi_free_board_minor(i);
2181                 return retval;
2182         }
2183         retval = device_create_file(csdev, &dev_attr_max_write_buffer_kb);
2184         if (retval) {
2185                 printk(KERN_ERR
2186                        "comedi: "
2187                        "failed to create sysfs attribute file \"%s\".\n",
2188                        dev_attr_max_write_buffer_kb.attr.name);
2189                 comedi_free_board_minor(i);
2190                 return retval;
2191         }
2192         retval = device_create_file(csdev, &dev_attr_write_buffer_kb);
2193         if (retval) {
2194                 printk(KERN_ERR
2195                        "comedi: "
2196                        "failed to create sysfs attribute file \"%s\".\n",
2197                        dev_attr_write_buffer_kb.attr.name);
2198                 comedi_free_board_minor(i);
2199                 return retval;
2200         }
2201         return i;
2202 }
2203
2204 void comedi_free_board_minor(unsigned minor)
2205 {
2206         unsigned long flags;
2207         struct comedi_device_file_info *info;
2208
2209         BUG_ON(minor >= COMEDI_NUM_BOARD_MINORS);
2210         spin_lock_irqsave(&comedi_file_info_table_lock, flags);
2211         info = comedi_file_info_table[minor];
2212         comedi_file_info_table[minor] = NULL;
2213         spin_unlock_irqrestore(&comedi_file_info_table_lock, flags);
2214
2215         if (info) {
2216                 struct comedi_device *dev = info->device;
2217                 if (dev) {
2218                         if (dev->class_dev) {
2219                                 device_destroy(comedi_class,
2220                                                MKDEV(COMEDI_MAJOR, dev->minor));
2221                         }
2222                         comedi_device_cleanup(dev);
2223                         kfree(dev);
2224                 }
2225                 kfree(info);
2226         }
2227 }
2228
2229 int comedi_alloc_subdevice_minor(struct comedi_device *dev,
2230                                  struct comedi_subdevice *s)
2231 {
2232         unsigned long flags;
2233         struct comedi_device_file_info *info;
2234         struct device *csdev;
2235         unsigned i;
2236         int retval;
2237
2238         info = kmalloc(sizeof(struct comedi_device_file_info), GFP_KERNEL);
2239         if (info == NULL)
2240                 return -ENOMEM;
2241         info->device = dev;
2242         info->read_subdevice = s;
2243         info->write_subdevice = s;
2244         spin_lock_irqsave(&comedi_file_info_table_lock, flags);
2245         for (i = COMEDI_FIRST_SUBDEVICE_MINOR; i < COMEDI_NUM_MINORS; ++i) {
2246                 if (comedi_file_info_table[i] == NULL) {
2247                         comedi_file_info_table[i] = info;
2248                         break;
2249                 }
2250         }
2251         spin_unlock_irqrestore(&comedi_file_info_table_lock, flags);
2252         if (i == COMEDI_NUM_MINORS) {
2253                 kfree(info);
2254                 printk(KERN_ERR
2255                        "comedi: error: "
2256                        "ran out of minor numbers for board device files.\n");
2257                 return -EBUSY;
2258         }
2259         s->minor = i;
2260         csdev = COMEDI_DEVICE_CREATE(comedi_class, dev->class_dev,
2261                                      MKDEV(COMEDI_MAJOR, i), NULL, NULL,
2262                                      "comedi%i_subd%i", dev->minor,
2263                                      (int)(s - dev->subdevices));
2264         if (!IS_ERR(csdev))
2265                 s->class_dev = csdev;
2266         dev_set_drvdata(csdev, info);
2267         retval = device_create_file(csdev, &dev_attr_max_read_buffer_kb);
2268         if (retval) {
2269                 printk(KERN_ERR
2270                        "comedi: "
2271                        "failed to create sysfs attribute file \"%s\".\n",
2272                        dev_attr_max_read_buffer_kb.attr.name);
2273                 comedi_free_subdevice_minor(s);
2274                 return retval;
2275         }
2276         retval = device_create_file(csdev, &dev_attr_read_buffer_kb);
2277         if (retval) {
2278                 printk(KERN_ERR
2279                        "comedi: "
2280                        "failed to create sysfs attribute file \"%s\".\n",
2281                        dev_attr_read_buffer_kb.attr.name);
2282                 comedi_free_subdevice_minor(s);
2283                 return retval;
2284         }
2285         retval = device_create_file(csdev, &dev_attr_max_write_buffer_kb);
2286         if (retval) {
2287                 printk(KERN_ERR
2288                        "comedi: "
2289                        "failed to create sysfs attribute file \"%s\".\n",
2290                        dev_attr_max_write_buffer_kb.attr.name);
2291                 comedi_free_subdevice_minor(s);
2292                 return retval;
2293         }
2294         retval = device_create_file(csdev, &dev_attr_write_buffer_kb);
2295         if (retval) {
2296                 printk(KERN_ERR
2297                        "comedi: "
2298                        "failed to create sysfs attribute file \"%s\".\n",
2299                        dev_attr_write_buffer_kb.attr.name);
2300                 comedi_free_subdevice_minor(s);
2301                 return retval;
2302         }
2303         return i;
2304 }
2305
2306 void comedi_free_subdevice_minor(struct comedi_subdevice *s)
2307 {
2308         unsigned long flags;
2309         struct comedi_device_file_info *info;
2310
2311         if (s == NULL)
2312                 return;
2313         if (s->minor < 0)
2314                 return;
2315
2316         BUG_ON(s->minor >= COMEDI_NUM_MINORS);
2317         BUG_ON(s->minor < COMEDI_FIRST_SUBDEVICE_MINOR);
2318
2319         spin_lock_irqsave(&comedi_file_info_table_lock, flags);
2320         info = comedi_file_info_table[s->minor];
2321         comedi_file_info_table[s->minor] = NULL;
2322         spin_unlock_irqrestore(&comedi_file_info_table_lock, flags);
2323
2324         if (s->class_dev) {
2325                 device_destroy(comedi_class, MKDEV(COMEDI_MAJOR, s->minor));
2326                 s->class_dev = NULL;
2327         }
2328         kfree(info);
2329 }
2330
2331 struct comedi_device_file_info *comedi_get_device_file_info(unsigned minor)
2332 {
2333         unsigned long flags;
2334         struct comedi_device_file_info *info;
2335
2336         BUG_ON(minor >= COMEDI_NUM_MINORS);
2337         spin_lock_irqsave(&comedi_file_info_table_lock, flags);
2338         info = comedi_file_info_table[minor];
2339         spin_unlock_irqrestore(&comedi_file_info_table_lock, flags);
2340         return info;
2341 }
2342 EXPORT_SYMBOL_GPL(comedi_get_device_file_info);
2343
2344 static int resize_async_buffer(struct comedi_device *dev,
2345                                struct comedi_subdevice *s,
2346                                struct comedi_async *async, unsigned new_size)
2347 {
2348         int retval;
2349
2350         if (new_size > async->max_bufsize)
2351                 return -EPERM;
2352
2353         if (s->busy) {
2354                 DPRINTK("subdevice is busy, cannot resize buffer\n");
2355                 return -EBUSY;
2356         }
2357         if (async->mmap_count) {
2358                 DPRINTK("subdevice is mmapped, cannot resize buffer\n");
2359                 return -EBUSY;
2360         }
2361
2362         if (!async->prealloc_buf)
2363                 return -EINVAL;
2364
2365         /* make sure buffer is an integral number of pages
2366          * (we round up) */
2367         new_size = (new_size + PAGE_SIZE - 1) & PAGE_MASK;
2368
2369         retval = comedi_buf_alloc(dev, s, new_size);
2370         if (retval < 0)
2371                 return retval;
2372
2373         if (s->buf_change) {
2374                 retval = s->buf_change(dev, s, new_size);
2375                 if (retval < 0)
2376                         return retval;
2377         }
2378
2379         DPRINTK("comedi%i subd %d buffer resized to %i bytes\n",
2380                 dev->minor, (int)(s - dev->subdevices), async->prealloc_bufsz);
2381         return 0;
2382 }
2383
2384 /* sysfs attribute files */
2385
2386 static const unsigned bytes_per_kibi = 1024;
2387
2388 static ssize_t show_max_read_buffer_kb(struct device *dev,
2389                                        struct device_attribute *attr, char *buf)
2390 {
2391         ssize_t retval;
2392         struct comedi_device_file_info *info = dev_get_drvdata(dev);
2393         unsigned max_buffer_size_kb = 0;
2394         struct comedi_subdevice *const read_subdevice =
2395             comedi_get_read_subdevice(info);
2396
2397         mutex_lock(&info->device->mutex);
2398         if (read_subdevice &&
2399             (read_subdevice->subdev_flags & SDF_CMD_READ) &&
2400             read_subdevice->async) {
2401                 max_buffer_size_kb = read_subdevice->async->max_bufsize /
2402                     bytes_per_kibi;
2403         }
2404         retval = snprintf(buf, PAGE_SIZE, "%i\n", max_buffer_size_kb);
2405         mutex_unlock(&info->device->mutex);
2406
2407         return retval;
2408 }
2409
2410 static ssize_t store_max_read_buffer_kb(struct device *dev,
2411                                         struct device_attribute *attr,
2412                                         const char *buf, size_t count)
2413 {
2414         struct comedi_device_file_info *info = dev_get_drvdata(dev);
2415         unsigned long new_max_size_kb;
2416         uint64_t new_max_size;
2417         struct comedi_subdevice *const read_subdevice =
2418             comedi_get_read_subdevice(info);
2419
2420         if (strict_strtoul(buf, 10, &new_max_size_kb))
2421                 return -EINVAL;
2422         if (new_max_size_kb != (uint32_t) new_max_size_kb)
2423                 return -EINVAL;
2424         new_max_size = ((uint64_t) new_max_size_kb) * bytes_per_kibi;
2425         if (new_max_size != (uint32_t) new_max_size)
2426                 return -EINVAL;
2427
2428         mutex_lock(&info->device->mutex);
2429         if (read_subdevice == NULL ||
2430             (read_subdevice->subdev_flags & SDF_CMD_READ) == 0 ||
2431             read_subdevice->async == NULL) {
2432                 mutex_unlock(&info->device->mutex);
2433                 return -EINVAL;
2434         }
2435         read_subdevice->async->max_bufsize = new_max_size;
2436         mutex_unlock(&info->device->mutex);
2437
2438         return count;
2439 }
2440
2441 static struct device_attribute dev_attr_max_read_buffer_kb = {
2442         .attr = {
2443                  .name = "max_read_buffer_kb",
2444                  .mode = S_IRUGO | S_IWUSR},
2445         .show = &show_max_read_buffer_kb,
2446         .store = &store_max_read_buffer_kb
2447 };
2448
2449 static ssize_t show_read_buffer_kb(struct device *dev,
2450                                    struct device_attribute *attr, char *buf)
2451 {
2452         ssize_t retval;
2453         struct comedi_device_file_info *info = dev_get_drvdata(dev);
2454         unsigned buffer_size_kb = 0;
2455         struct comedi_subdevice *const read_subdevice =
2456             comedi_get_read_subdevice(info);
2457
2458         mutex_lock(&info->device->mutex);
2459         if (read_subdevice &&
2460             (read_subdevice->subdev_flags & SDF_CMD_READ) &&
2461             read_subdevice->async) {
2462                 buffer_size_kb = read_subdevice->async->prealloc_bufsz /
2463                     bytes_per_kibi;
2464         }
2465         retval = snprintf(buf, PAGE_SIZE, "%i\n", buffer_size_kb);
2466         mutex_unlock(&info->device->mutex);
2467
2468         return retval;
2469 }
2470
2471 static ssize_t store_read_buffer_kb(struct device *dev,
2472                                     struct device_attribute *attr,
2473                                     const char *buf, size_t count)
2474 {
2475         struct comedi_device_file_info *info = dev_get_drvdata(dev);
2476         unsigned long new_size_kb;
2477         uint64_t new_size;
2478         int retval;
2479         struct comedi_subdevice *const read_subdevice =
2480             comedi_get_read_subdevice(info);
2481
2482         if (strict_strtoul(buf, 10, &new_size_kb))
2483                 return -EINVAL;
2484         if (new_size_kb != (uint32_t) new_size_kb)
2485                 return -EINVAL;
2486         new_size = ((uint64_t) new_size_kb) * bytes_per_kibi;
2487         if (new_size != (uint32_t) new_size)
2488                 return -EINVAL;
2489
2490         mutex_lock(&info->device->mutex);
2491         if (read_subdevice == NULL ||
2492             (read_subdevice->subdev_flags & SDF_CMD_READ) == 0 ||
2493             read_subdevice->async == NULL) {
2494                 mutex_unlock(&info->device->mutex);
2495                 return -EINVAL;
2496         }
2497         retval = resize_async_buffer(info->device, read_subdevice,
2498                                      read_subdevice->async, new_size);
2499         mutex_unlock(&info->device->mutex);
2500
2501         if (retval < 0)
2502                 return retval;
2503         return count;
2504 }
2505
2506 static struct device_attribute dev_attr_read_buffer_kb = {
2507         .attr = {
2508                  .name = "read_buffer_kb",
2509                  .mode = S_IRUGO | S_IWUSR | S_IWGRP},
2510         .show = &show_read_buffer_kb,
2511         .store = &store_read_buffer_kb
2512 };
2513
2514 static ssize_t show_max_write_buffer_kb(struct device *dev,
2515                                         struct device_attribute *attr,
2516                                         char *buf)
2517 {
2518         ssize_t retval;
2519         struct comedi_device_file_info *info = dev_get_drvdata(dev);
2520         unsigned max_buffer_size_kb = 0;
2521         struct comedi_subdevice *const write_subdevice =
2522             comedi_get_write_subdevice(info);
2523
2524         mutex_lock(&info->device->mutex);
2525         if (write_subdevice &&
2526             (write_subdevice->subdev_flags & SDF_CMD_WRITE) &&
2527             write_subdevice->async) {
2528                 max_buffer_size_kb = write_subdevice->async->max_bufsize /
2529                     bytes_per_kibi;
2530         }
2531         retval = snprintf(buf, PAGE_SIZE, "%i\n", max_buffer_size_kb);
2532         mutex_unlock(&info->device->mutex);
2533
2534         return retval;
2535 }
2536
2537 static ssize_t store_max_write_buffer_kb(struct device *dev,
2538                                          struct device_attribute *attr,
2539                                          const char *buf, size_t count)
2540 {
2541         struct comedi_device_file_info *info = dev_get_drvdata(dev);
2542         unsigned long new_max_size_kb;
2543         uint64_t new_max_size;
2544         struct comedi_subdevice *const write_subdevice =
2545             comedi_get_write_subdevice(info);
2546
2547         if (strict_strtoul(buf, 10, &new_max_size_kb))
2548                 return -EINVAL;
2549         if (new_max_size_kb != (uint32_t) new_max_size_kb)
2550                 return -EINVAL;
2551         new_max_size = ((uint64_t) new_max_size_kb) * bytes_per_kibi;
2552         if (new_max_size != (uint32_t) new_max_size)
2553                 return -EINVAL;
2554
2555         mutex_lock(&info->device->mutex);
2556         if (write_subdevice == NULL ||
2557             (write_subdevice->subdev_flags & SDF_CMD_WRITE) == 0 ||
2558             write_subdevice->async == NULL) {
2559                 mutex_unlock(&info->device->mutex);
2560                 return -EINVAL;
2561         }
2562         write_subdevice->async->max_bufsize = new_max_size;
2563         mutex_unlock(&info->device->mutex);
2564
2565         return count;
2566 }
2567
2568 static struct device_attribute dev_attr_max_write_buffer_kb = {
2569         .attr = {
2570                  .name = "max_write_buffer_kb",
2571                  .mode = S_IRUGO | S_IWUSR},
2572         .show = &show_max_write_buffer_kb,
2573         .store = &store_max_write_buffer_kb
2574 };
2575
2576 static ssize_t show_write_buffer_kb(struct device *dev,
2577                                     struct device_attribute *attr, char *buf)
2578 {
2579         ssize_t retval;
2580         struct comedi_device_file_info *info = dev_get_drvdata(dev);
2581         unsigned buffer_size_kb = 0;
2582         struct comedi_subdevice *const write_subdevice =
2583             comedi_get_write_subdevice(info);
2584
2585         mutex_lock(&info->device->mutex);
2586         if (write_subdevice &&
2587             (write_subdevice->subdev_flags & SDF_CMD_WRITE) &&
2588             write_subdevice->async) {
2589                 buffer_size_kb = write_subdevice->async->prealloc_bufsz /
2590                     bytes_per_kibi;
2591         }
2592         retval = snprintf(buf, PAGE_SIZE, "%i\n", buffer_size_kb);
2593         mutex_unlock(&info->device->mutex);
2594
2595         return retval;
2596 }
2597
2598 static ssize_t store_write_buffer_kb(struct device *dev,
2599                                      struct device_attribute *attr,
2600                                      const char *buf, size_t count)
2601 {
2602         struct comedi_device_file_info *info = dev_get_drvdata(dev);
2603         unsigned long new_size_kb;
2604         uint64_t new_size;
2605         int retval;
2606         struct comedi_subdevice *const write_subdevice =
2607             comedi_get_write_subdevice(info);
2608
2609         if (strict_strtoul(buf, 10, &new_size_kb))
2610                 return -EINVAL;
2611         if (new_size_kb != (uint32_t) new_size_kb)
2612                 return -EINVAL;
2613         new_size = ((uint64_t) new_size_kb) * bytes_per_kibi;
2614         if (new_size != (uint32_t) new_size)
2615                 return -EINVAL;
2616
2617         mutex_lock(&info->device->mutex);
2618         if (write_subdevice == NULL ||
2619             (write_subdevice->subdev_flags & SDF_CMD_WRITE) == 0 ||
2620             write_subdevice->async == NULL) {
2621                 mutex_unlock(&info->device->mutex);
2622                 return -EINVAL;
2623         }
2624         retval = resize_async_buffer(info->device, write_subdevice,
2625                                      write_subdevice->async, new_size);
2626         mutex_unlock(&info->device->mutex);
2627
2628         if (retval < 0)
2629                 return retval;
2630         return count;
2631 }
2632
2633 static struct device_attribute dev_attr_write_buffer_kb = {
2634         .attr = {
2635                  .name = "write_buffer_kb",
2636                  .mode = S_IRUGO | S_IWUSR | S_IWGRP},
2637         .show = &show_write_buffer_kb,
2638         .store = &store_write_buffer_kb
2639 };