drivers/usb/hiddev.c

   1 /*
   2  *  Copyright (c) 2001 Paul Stewart
   3  *  Copyright (c) 2001 Vojtech Pavlik
   4  *
   5  *  HID char devices, giving access to raw HID device events.
   6  *
   7  */
   8
   9 /*
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  23  *
  24  * Should you need to contact me, the author, you can do so either by
  25  * e-mail - mail your message to Paul Stewart <stewart@wetlogic.net>
  26  */
  27
  28 #define HIDDEV_MINOR_BASE       96
  29 #define HIDDEV_MINORS           16
  30 #define HIDDEV_BUFFER_SIZE      64
  31
  32 #include <linux/poll.h>
  33 #include <linux/slab.h>
  34 #include <linux/module.h>
  35 #include <linux/init.h>
  36 #include <linux/smp_lock.h>
  37 #include <linux/input.h>
  38 #include <linux/usb.h>
  39 #include "hid.h"
  40 #include <linux/hiddev.h>
  41
  42 struct hiddev {
  43         int exist;
  44         int open;
  45         int minor;
  46         wait_queue_head_t wait;
  47         devfs_handle_t devfs;
  48         struct hid_device *hid;
  49         struct hiddev_list *list;
  50 };
  51
  52 struct hiddev_list {
  53         struct hiddev_usage_ref buffer[HIDDEV_BUFFER_SIZE];
  54         int head;
  55         int tail;
  56         unsigned flags;
  57         struct fasync_struct *fasync;
  58         struct hiddev *hiddev;
  59         struct hiddev_list *next;
  60 };
  61
  62 static struct hiddev *hiddev_table[HIDDEV_MINORS];
  63 static devfs_handle_t hiddev_devfs_handle;
  64
  65 /*
  66  * Find a report, given the report's type and ID.  The ID can be specified
  67  * indirectly by REPORT_ID_FIRST (which returns the first report of the given
  68  * type) or by (REPORT_ID_NEXT | old_id), which returns the next report of the
  69  * given type which follows old_id.
  70  */
  71 static struct hid_report *
  72 hiddev_lookup_report(struct hid_device *hid, struct hiddev_report_info *rinfo)
  73 {
  74         unsigned flags = rinfo->report_id & ~HID_REPORT_ID_MASK;
  75         struct hid_report_enum *report_enum = NULL;
  76         struct list_head *list;
  77
  78         if (rinfo->report_type < HID_REPORT_TYPE_MIN ||
  79             rinfo->report_type > HID_REPORT_TYPE_MAX) return NULL;
  80
  81         report_enum = hid->report_enum +
  82                 (rinfo->report_type - HID_REPORT_TYPE_MIN);
  83
  84         switch (flags) {
  85         case 0: /* Nothing to do -- report_id is already set correctly */
  86                 break;
  87
  88         case HID_REPORT_ID_FIRST:
  89                 list = report_enum->report_list.next;
  90                 if (list == &report_enum->report_list) return NULL;
  91                 rinfo->report_id = ((struct hid_report *) list)->id;
  92                 break;
  93
  94         case HID_REPORT_ID_NEXT:
  95                 list = (struct list_head *)
  96                         report_enum->report_id_hash[rinfo->report_id &
  97                                                     HID_REPORT_ID_MASK];
  98                 if (list == NULL) return NULL;
  99                 list = list->next;
 100                 if (list == &report_enum->report_list) return NULL;
 101                 rinfo->report_id = ((struct hid_report *) list)->id;
 102                 break;
 103
 104         default:
 105                 return NULL;
 106         }
 107
 108         return report_enum->report_id_hash[rinfo->report_id];
 109 }
 110
 111 /*
 112  * Perform an exhaustive search of the report table for a usage, given its
 113  * type and usage id.
 114  */
 115 static struct hid_field *
 116 hiddev_lookup_usage(struct hid_device *hid, struct hiddev_usage_ref *uref)
 117 {
 118         int i, j;
 119         struct hid_report *report;
 120         struct hid_report_enum *report_enum;
 121         struct list_head *list;
 122         struct hid_field *field;
 123
 124         if (uref->report_type < HID_REPORT_TYPE_MIN ||
 125             uref->report_type > HID_REPORT_TYPE_MAX) return NULL;
 126
 127         report_enum = hid->report_enum +
 128                 (uref->report_type - HID_REPORT_TYPE_MIN);
 129         list = report_enum->report_list.next;
 130         while (list != &report_enum->report_list) {
 131                 report = (struct hid_report *) list;
 132                 for (i = 0; i < report->maxfield; i++) {
 133                         field = report->field[i];
 134                         for (j = 0; j < field->maxusage; j++) {
 135                                 if (field->usage[j].hid == uref->usage_code) {
 136                                         uref->report_id = report->id;
 137                                         uref->field_index = i;
 138                                         uref->usage_index = j;
 139                                         return field;
 140                                 }
 141                         }
 142                 }
 143                 list = list->next;
 144         }
 145
 146         return NULL;
 147 }
 148
 149 static void hiddev_send_event(struct hid_device *hid,
 150                               struct hiddev_usage_ref *uref)
 151 {
 152         struct hiddev *hiddev = hid->hiddev;
 153         struct hiddev_list *list = hiddev->list;
 154
 155         while (list) {
 156                 if (uref->field_index != HID_FIELD_INDEX_NONE ||
 157                     (list->flags & HIDDEV_FLAG_REPORT) != 0) {
 158                         list->buffer[list->head] = *uref;
 159                         list->head = (list->head + 1) &
 160                                 (HIDDEV_BUFFER_SIZE - 1);
 161                         kill_fasync(&list->fasync, SIGIO, POLL_IN);
 162                 }
 163
 164                 list = list->next;
 165         }
 166
 167         wake_up_interruptible(&hiddev->wait);
 168 }
 169
 170 /*
 171  * This is where hid.c calls into hiddev to pass an event that occurred over
 172  * the interrupt pipe
 173  */
 174 void hiddev_hid_event(struct hid_device *hid, struct hid_field *field,
 175                       struct hid_usage *usage, __s32 value)
 176 {
 177         unsigned type = field->report_type;
 178         struct hiddev_usage_ref uref;
 179
 180         uref.report_type =
 181           (type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
 182           ((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
 183            ((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE:0));
 184         uref.report_id = field->report->id;
 185         uref.field_index = field->index;
 186         uref.usage_index = (usage - field->usage);
 187         uref.usage_code = usage->hid;
 188         uref.value = value;
 189
 190         hiddev_send_event(hid, &uref);
 191 }
 192
 193
 194 void hiddev_report_event(struct hid_device *hid, struct hid_report *report)
 195 {
 196         unsigned type = report->type;
 197         struct hiddev_usage_ref uref;
 198
 199         memset(&uref, 0, sizeof(uref));
 200         uref.report_type =
 201           (type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
 202           ((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
 203            ((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE:0));
 204         uref.report_id = report->id;
 205         uref.field_index = HID_FIELD_INDEX_NONE;
 206
 207         hiddev_send_event(hid, &uref);
 208 }
 209
 210 /*
 211  * fasync file op
 212  */
 213 static int hiddev_fasync(int fd, struct file *file, int on)
 214 {
 215         int retval;
 216         struct hiddev_list *list = file->private_data;
 217         retval = fasync_helper(fd, file, on, &list->fasync);
 218         return retval < 0 ? retval : 0;
 219 }
 220
 221 /*
 222  * De-allocate a hiddev structure
 223  */
 224 static void hiddev_cleanup(struct hiddev *hiddev)
 225 {
 226         devfs_unregister(hiddev->devfs);
 227         hiddev_table[hiddev->minor] = NULL;
 228         kfree(hiddev);
 229 }
 230
 231 /*
 232  * release file op
 233  */
 234 static int hiddev_release(struct inode * inode, struct file * file)
 235 {
 236         struct hiddev_list *list = file->private_data;
 237         struct hiddev_list **listptr;
 238
 239         listptr = &list->hiddev->list;
 240         hiddev_fasync(-1, file, 0);
 241
 242         while (*listptr && (*listptr != list))
 243                 listptr = &((*listptr)->next);
 244         *listptr = (*listptr)->next;
 245
 246         if (!--list->hiddev->open) {
 247                 if (list->hiddev->exist)
 248                         hid_close(list->hiddev->hid);
 249                 else
 250                         hiddev_cleanup(list->hiddev);
 251         }
 252
 253         kfree(list);
 254
 255         return 0;
 256 }
 257
 258 /*
 259  * open file op
 260  */
 261 static int hiddev_open(struct inode * inode, struct file * file) {
 262         struct hiddev_list *list;
 263
 264         int i = MINOR(inode->i_rdev) - HIDDEV_MINOR_BASE;
 265
 266         if (i >= HIDDEV_MINORS || !hiddev_table[i])
 267                 return -ENODEV;
 268
 269         if (!(list = kmalloc(sizeof(struct hiddev_list), GFP_KERNEL)))
 270                 return -ENOMEM;
 271         memset(list, 0, sizeof(struct hiddev_list));
 272
 273         list->hiddev = hiddev_table[i];
 274         list->next = hiddev_table[i]->list;
 275         hiddev_table[i]->list = list;
 276
 277         file->private_data = list;
 278
 279         if (!list->hiddev->open++)
 280                 if (list->hiddev->exist)
 281                         hid_open(hiddev_table[i]->hid);
 282
 283         return 0;
 284 }
 285
 286 /*
 287  * "write" file op
 288  */
 289 static ssize_t hiddev_write(struct file * file, const char * buffer,
 290                             size_t count, loff_t *ppos)
 291 {
 292         return -EINVAL;
 293 }
 294
 295 /*
 296  * "read" file op
 297  */
 298 static ssize_t hiddev_read(struct file * file, char * buffer, size_t count,
 299                            loff_t *ppos)
 300 {
 301         DECLARE_WAITQUEUE(wait, current);
 302         struct hiddev_list *list = file->private_data;
 303         int event_size;
 304         int retval = 0;
 305
 306         event_size = ((list->flags & HIDDEV_FLAG_UREF) != 0) ?
 307                 sizeof(struct hiddev_usage_ref) : sizeof(struct hiddev_event);
 308
 309         if (count < event_size) return 0;
 310
 311         while (retval == 0) {
 312                 if (list->head == list->tail) {
 313                         add_wait_queue(&list->hiddev->wait, &wait);
 314                         set_current_state(TASK_INTERRUPTIBLE);
 315
 316                         while (list->head == list->tail) {
 317                                 if (file->f_flags & O_NONBLOCK) {
 318                                         retval = -EAGAIN;
 319                                         break;
 320                                 }
 321                                 if (signal_pending(current)) {
 322                                         retval = -ERESTARTSYS;
 323                                         break;
 324                                 }
 325                                 if (!list->hiddev->exist) {
 326                                         retval = -EIO;
 327                                         break;
 328                                 }
 329
 330                                 schedule();
 331                         }
 332
 333                         set_current_state(TASK_RUNNING);
 334                         remove_wait_queue(&list->hiddev->wait, &wait);
 335                 }
 336
 337                 if (retval)
 338                         return retval;
 339
 340                 while (list->head != list->tail &&
 341                        retval + event_size <= count) {
 342                         if ((list->flags & HIDDEV_FLAG_UREF) == 0) {
 343                                 if (list->buffer[list->tail].field_index !=
 344                                     HID_FIELD_INDEX_NONE) {
 345                                         struct hiddev_event event;
 346                                         event.hid = list->buffer[list->tail].usage_code;
 347                                         event.value = list->buffer[list->tail].value;
 348                                         if (copy_to_user(buffer + retval, &event, sizeof(struct hiddev_event)))
 349                                                 return -EFAULT;
 350                                         retval += sizeof(struct hiddev_event);
 351                                 }
 352                         } else {
 353                                 if (list->buffer[list->tail].field_index != HID_FIELD_INDEX_NONE ||
 354                                     (list->flags & HIDDEV_FLAG_REPORT) != 0) {
 355                                         if (copy_to_user(buffer + retval, list->buffer + list->tail, sizeof(struct hiddev_usage_ref)))
 356                                                 return -EFAULT;
 357                                         retval += sizeof(struct hiddev_usage_ref);
 358                                 }
 359                         }
 360                         list->tail = (list->tail + 1) & (HIDDEV_BUFFER_SIZE - 1);
 361                 }
 362
 363         }
 364
 365         return retval;
 366 }
 367
 368 /*
 369  * "poll" file op
 370  * No kernel lock - fine
 371  */
 372 static unsigned int hiddev_poll(struct file *file, poll_table *wait)
 373 {
 374         struct hiddev_list *list = file->private_data;
 375         poll_wait(file, &list->hiddev->wait, wait);
 376         if (list->head != list->tail)
 377                 return POLLIN | POLLRDNORM;
 378         if (!list->hiddev->exist)
 379                 return POLLERR | POLLHUP;
 380         return 0;
 381 }
 382
 383 #define GET_TIMEOUT 3
 384 #define SET_TIMEOUT 3
 385
 386 /*
 387  * "ioctl" file op
 388  */
 389 static int hiddev_ioctl(struct inode *inode, struct file *file,
 390                         unsigned int cmd, unsigned long arg)
 391 {
 392         struct hiddev_list *list = file->private_data;
 393         struct hiddev *hiddev = list->hiddev;
 394         struct hid_device *hid = hiddev->hid;
 395         struct usb_device *dev = hid->dev;
 396         struct hiddev_collection_info cinfo;
 397         struct hiddev_report_info rinfo;
 398         struct hiddev_field_info finfo;
 399         struct hiddev_usage_ref_multi uref_multi;
 400         struct hiddev_usage_ref *uref = &uref_multi.uref;
 401         struct hiddev_devinfo dinfo;
 402         struct hid_report *report;
 403         struct hid_field *field;
 404         int i;
 405
 406         if (!hiddev->exist) return -EIO;
 407
 408         switch (cmd) {
 409
 410         case HIDIOCGVERSION:
 411                 return put_user(HID_VERSION, (int *) arg);
 412
 413         case HIDIOCAPPLICATION:
 414                 if (arg < 0 || arg >= hid->maxapplication)
 415                         return -EINVAL;
 416
 417                 for (i = 0; i < hid->maxcollection; i++)
 418                         if (hid->collection[i].type ==
 419                             HID_COLLECTION_APPLICATION && arg-- == 0)
 420                                 break;
 421
 422                 if (i == hid->maxcollection)
 423                         return -EINVAL;
 424
 425                 return hid->collection[i].usage;
 426
 427         case HIDIOCGDEVINFO:
 428                 dinfo.bustype = BUS_USB;
 429                 dinfo.busnum = dev->bus->busnum;
 430                 dinfo.devnum = dev->devnum;
 431                 dinfo.ifnum = hid->ifnum;
 432                 dinfo.vendor = dev->descriptor.idVendor;
 433                 dinfo.product = dev->descriptor.idProduct;
 434                 dinfo.version = dev->descriptor.bcdDevice;
 435                 dinfo.num_applications = hid->maxapplication;
 436                 if (copy_to_user((void *) arg, &dinfo, sizeof(dinfo)))
 437                         return -EFAULT;
 438                 return 0;
 439
 440         case HIDIOCGFLAG:
 441                 return put_user(list->flags, (int *) arg);
 442
 443         case HIDIOCSFLAG:
 444                 {
 445                         int newflags;
 446                         if (get_user(newflags, (int *) arg))
 447                                 return -EFAULT;
 448
 449                         if ((newflags & ~HIDDEV_FLAGS) != 0 ||
 450                             ((newflags & HIDDEV_FLAG_REPORT) != 0 &&
 451                              (newflags & HIDDEV_FLAG_UREF) == 0))
 452                                 return -EINVAL;
 453
 454                         list->flags = newflags;
 455
 456                         return 0;
 457                 }
 458
 459         case HIDIOCGSTRING:
 460                 {
 461                         int idx, len;
 462                         char *buf;
 463
 464                         if (get_user(idx, (int *) arg))
 465                                 return -EFAULT;
 466
 467                         if ((buf = kmalloc(HID_STRING_SIZE, GFP_KERNEL)) == NULL)
 468                                 return -ENOMEM;
 469
 470                         if ((len = usb_string(dev, idx, buf, HID_STRING_SIZE-1)) < 0) {
 471                                 kfree(buf);
 472                                 return -EINVAL;
 473                         }
 474
 475                         if (copy_to_user((void *) (arg+sizeof(int)), buf, len+1)) {
 476                                 kfree(buf);
 477                                 return -EFAULT;
 478                         }
 479
 480                         kfree(buf);
 481
 482                         return len;
 483                 }
 484
 485         case HIDIOCINITREPORT:
 486                 hid_init_reports(hid);
 487
 488                 return 0;
 489
 490         case HIDIOCGREPORT:
 491                 if (copy_from_user(&rinfo, (void *) arg, sizeof(rinfo)))
 492                         return -EFAULT;
 493
 494                 if (rinfo.report_type == HID_REPORT_TYPE_OUTPUT)
 495                         return -EINVAL;
 496
 497                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 498                         return -EINVAL;
 499
 500                 hid_read_report(hid, report);
 501
 502                 return 0;
 503
 504         case HIDIOCSREPORT:
 505                 if (copy_from_user(&rinfo, (void *) arg, sizeof(rinfo)))
 506                         return -EFAULT;
 507
 508                 if (rinfo.report_type == HID_REPORT_TYPE_INPUT)
 509                         return -EINVAL;
 510
 511                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 512                         return -EINVAL;
 513
 514                 hid_write_report(hid, report);
 515
 516                 return 0;
 517
 518         case HIDIOCGREPORTINFO:
 519                 if (copy_from_user(&rinfo, (void *) arg, sizeof(rinfo)))
 520                         return -EFAULT;
 521
 522                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 523                         return -EINVAL;
 524
 525                 rinfo.num_fields = report->maxfield;
 526
 527                 if (copy_to_user((void *) arg, &rinfo, sizeof(rinfo)))
 528                         return -EFAULT;
 529                 return 0;
 530
 531         case HIDIOCGFIELDINFO:
 532                 if (copy_from_user(&finfo, (void *) arg, sizeof(finfo)))
 533                         return -EFAULT;
 534                 rinfo.report_type = finfo.report_type;
 535                 rinfo.report_id = finfo.report_id;
 536                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 537                         return -EINVAL;
 538
 539                 if (finfo.field_index >= report->maxfield)
 540                         return -EINVAL;
 541
 542                 field = report->field[finfo.field_index];
 543                 memset(&finfo, 0, sizeof(finfo));
 544                 finfo.report_type = rinfo.report_type;
 545                 finfo.report_id = rinfo.report_id;
 546                 finfo.field_index = field->report_count - 1;
 547                 finfo.maxusage = field->maxusage;
 548                 finfo.flags = field->flags;
 549                 finfo.physical = field->physical;
 550                 finfo.logical = field->logical;
 551                 finfo.application = field->application;
 552                 finfo.logical_minimum = field->logical_minimum;
 553                 finfo.logical_maximum = field->logical_maximum;
 554                 finfo.physical_minimum = field->physical_minimum;
 555                 finfo.physical_maximum = field->physical_maximum;
 556                 finfo.unit_exponent = field->unit_exponent;
 557                 finfo.unit = field->unit;
 558
 559                 if (copy_to_user((void *) arg, &finfo, sizeof(finfo)))
 560                         return -EFAULT;
 561                 return 0;
 562
 563         case HIDIOCGUCODE:
 564                 if (copy_from_user(uref, (void *) arg, sizeof(*uref)))
 565                         return -EFAULT;
 566
 567                 rinfo.report_type = uref->report_type;
 568                 rinfo.report_id = uref->report_id;
 569                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 570                         return -EINVAL;
 571
 572                 if (uref->field_index >= report->maxfield)
 573                         return -EINVAL;
 574
 575                 field = report->field[uref->field_index];
 576                 if (uref->usage_index >= field->maxusage)
 577                         return -EINVAL;
 578
 579                 uref->usage_code = field->usage[uref->usage_index].hid;
 580
 581                 if (copy_to_user((void *) arg, uref, sizeof(*uref)))
 582                         return -EFAULT;
 583                 return 0;
 584
 585         case HIDIOCGUSAGE:
 586         case HIDIOCSUSAGE:
 587         case HIDIOCGUSAGES:
 588         case HIDIOCSUSAGES:
 589         case HIDIOCGCOLLECTIONINDEX:
 590                 if (cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) {
 591                         if (copy_from_user(&uref_multi, (void *) arg,
 592                                            sizeof(uref_multi)))
 593                                 return -EFAULT;
 594                 } else {
 595                         if (copy_from_user(uref, (void *) arg, sizeof(*uref)))
 596                                 return -EFAULT;
 597                 }
 598
 599                 if (cmd != HIDIOCGUSAGE &&
 600                     cmd != HIDIOCGUSAGES &&
 601                     uref->report_type == HID_REPORT_TYPE_INPUT)
 602                         return -EINVAL;
 603
 604                 if (uref->report_id == HID_REPORT_ID_UNKNOWN) {
 605                         field = hiddev_lookup_usage(hid, uref);
 606                         if (field == NULL)
 607                                 return -EINVAL;
 608                 } else {
 609                         rinfo.report_type = uref->report_type;
 610                         rinfo.report_id = uref->report_id;
 611                         if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 612                                 return -EINVAL;
 613
 614                         if (uref->field_index >= report->maxfield)
 615                                 return -EINVAL;
 616
 617                         field = report->field[uref->field_index];
 618                         if (uref->usage_index >= field->maxusage)
 619                                 return -EINVAL;
 620
 621                         if (cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) {
 622                                 if (uref_multi.num_values >= HID_MAX_USAGES ||
 623                                     uref->usage_index >= field->maxusage ||
 624                                    (uref->usage_index + uref_multi.num_values) >= field->maxusage)
 625                                         return -EINVAL;
 626                         }
 627                 }
 628
 629                 switch (cmd) {
 630                 case HIDIOCGUSAGE:
 631                         uref->value = field->value[uref->usage_index];
 632                         return copy_to_user((void *) arg, uref, sizeof(*uref));
 633
 634                 case HIDIOCSUSAGE:
 635                         field->value[uref->usage_index] = uref->value;
 636                         return 0;
 637
 638                 case HIDIOCGCOLLECTIONINDEX:
 639                         return field->usage[uref->usage_index].collection_index;
 640                 case HIDIOCGUSAGES:
 641                         for (i = 0; i < uref_multi.num_values; i++)
 642                                 uref_multi.values[i] =
 643                                     field->value[uref->usage_index + i];
 644                         if (copy_to_user((void *) arg, &uref_multi,
 645                                          sizeof(uref_multi)))
 646                                 return -EFAULT;
 647                         return 0;
 648                 case HIDIOCSUSAGES:
 649                         for (i = 0; i < uref_multi.num_values; i++)
 650                                 field->value[uref->usage_index + i] =
 651                                     uref_multi.values[i];
 652                         return 0;
 653                 }
 654                 break;
 655
 656         case HIDIOCGCOLLECTIONINFO:
 657                 if (copy_from_user(&cinfo, (void *) arg, sizeof(cinfo)))
 658                         return -EFAULT;
 659
 660                 if (cinfo.index >= hid->maxcollection)
 661                         return -EINVAL;
 662
 663                 cinfo.type = hid->collection[cinfo.index].type;
 664                 cinfo.usage = hid->collection[cinfo.index].usage;
 665                 cinfo.level = hid->collection[cinfo.index].level;
 666
 667                 if (copy_to_user((void *) arg, &cinfo, sizeof(cinfo)))
 668                         return -EFAULT;
 669                 return 0;
 670
 671         default:
 672
 673                 if (_IOC_TYPE(cmd) != 'H' || _IOC_DIR(cmd) != _IOC_READ)
 674                         return -EINVAL;
 675
 676                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGNAME(0))) {
 677                         int len;
 678                         if (!hid->name) return 0;
 679                         len = strlen(hid->name) + 1;
 680                         if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
 681                         return copy_to_user((char *) arg, hid->name, len) ?
 682                                 -EFAULT : len;
 683                 }
 684         }
 685         return -EINVAL;
 686 }
 687
 688 static struct file_operations hiddev_fops = {
 689         owner:          THIS_MODULE,
 690         read:           hiddev_read,
 691         write:          hiddev_write,
 692         poll:           hiddev_poll,
 693         open:           hiddev_open,
 694         release:        hiddev_release,
 695         ioctl:          hiddev_ioctl,
 696         fasync:         hiddev_fasync,
 697 };
 698
 699 /*
 700  * This is where hid.c calls us to connect a hid device to the hiddev driver
 701  */
 702 int hiddev_connect(struct hid_device *hid)
 703 {
 704         struct hiddev *hiddev;
 705         int minor, i;
 706         char devfs_name[16];
 707
 708
 709
 710         if ((hid->quirks & HID_QUIRK_HIDDEV) == 0) {
 711                 for (i = 0; i < hid->maxcollection; i++)
 712                         if (hid->collection[i].type ==
 713                             HID_COLLECTION_APPLICATION &&
 714                             !IS_INPUT_APPLICATION(hid->collection[i].usage))
 715                                 break;
 716
 717                 if (i == hid->maxcollection)
 718                         return -1;
 719         }
 720
 721         for (minor = 0; minor < HIDDEV_MINORS && hiddev_table[minor]; minor++);
 722         if (minor == HIDDEV_MINORS) {
 723                 printk(KERN_ERR "hiddev: no more free hiddev devices\n");
 724                 return -1;
 725         }
 726
 727         if (!(hiddev = kmalloc(sizeof(struct hiddev), GFP_KERNEL)))
 728                 return -1;
 729         memset(hiddev, 0, sizeof(struct hiddev));
 730
 731         init_waitqueue_head(&hiddev->wait);
 732
 733         hiddev->minor = minor;
 734         hiddev_table[minor] = hiddev;
 735
 736         hiddev->hid = hid;
 737         hiddev->exist = 1;
 738
 739         sprintf(devfs_name, "hiddev%d", minor);
 740         hiddev->devfs = devfs_register(hiddev_devfs_handle, devfs_name,
 741                                        DEVFS_FL_DEFAULT, USB_MAJOR,
 742                                        minor + HIDDEV_MINOR_BASE,
 743                                        S_IFCHR | S_IRUGO | S_IWUSR,
 744                                        &hiddev_fops, NULL);
 745         hid->minor = minor;
 746         hid->hiddev = hiddev;
 747
 748         return 0;
 749 }
 750
 751 /*
 752  * This is where hid.c calls us to disconnect a hiddev device from the
 753  * corresponding hid device (usually because the usb device has disconnected)
 754  */
 755 void hiddev_disconnect(struct hid_device *hid)
 756 {
 757         struct hiddev *hiddev = hid->hiddev;
 758
 759         hiddev->exist = 0;
 760
 761         if (hiddev->open) {
 762                 hid_close(hiddev->hid);
 763                 wake_up_interruptible(&hiddev->wait);
 764         } else {
 765                 hiddev_cleanup(hiddev);
 766         }
 767 }
 768
 769 /* Currently this driver is a USB driver.  It's not a conventional one in
 770  * the sense that it doesn't probe at the USB level.  Instead it waits to
 771  * be connected by HID through the hiddev_connect / hiddev_disconnect
 772  * routines.  The reason to register as a USB device is to gain part of the
 773  * minor number space from the USB major.
 774  *
 775  * In theory, should the HID code be generalized to more than one physical
 776  * medium (say, IEEE 1384), this driver will probably need to register its
 777  * own major number, and in doing so, no longer need to register with USB.
 778  * At that point the probe routine and hiddev_driver struct below will no
 779  * longer be useful.
 780  */
 781
 782
 783 /* We never attach in this manner, and rely on HID to connect us.  This
 784  * is why there is no disconnect routine defined in the usb_driver either.
 785  */
 786 static void *hiddev_usbd_probe(struct usb_device *dev, unsigned int ifnum,
 787                           const struct usb_device_id *hiddev_info)
 788 {
 789         return NULL;
 790 }
 791
 792
 793 static /* const */ struct usb_driver hiddev_driver = {
 794         name:   "hiddev",
 795         probe:  hiddev_usbd_probe,
 796         fops:   &hiddev_fops,
 797         minor:  HIDDEV_MINOR_BASE
 798 };
 799
 800 int __init hiddev_init(void)
 801 {
 802         hiddev_devfs_handle =
 803                 devfs_mk_dir(devfs_find_handle(NULL, "usb", 0, 0, 0, 0), "hid", NULL);
 804         usb_register(&hiddev_driver);
 805         return 0;
 806 }
 807
 808 void __exit hiddev_exit(void)
 809 {
 810         devfs_unregister(hiddev_devfs_handle);
 811         usb_deregister(&hiddev_driver);
 812 }