drivers/usb/input/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 #include <linux/poll.h>
  29 #include <linux/slab.h>
  30 #include <linux/module.h>
  31 #include <linux/init.h>
  32 #include <linux/smp_lock.h>
  33 #include <linux/input.h>
  34 #include <linux/usb.h>
  35 #include <linux/hid.h>
  36 #include <linux/hiddev.h>
  37 #include "usbhid.h"
  38
  39 #ifdef CONFIG_USB_DYNAMIC_MINORS
  40 #define HIDDEV_MINOR_BASE       0
  41 #define HIDDEV_MINORS           256
  42 #else
  43 #define HIDDEV_MINOR_BASE       96
  44 #define HIDDEV_MINORS           16
  45 #endif
  46 #define HIDDEV_BUFFER_SIZE      64
  47
  48 struct hiddev {
  49         int exist;
  50         int open;
  51         wait_queue_head_t wait;
  52         struct hid_device *hid;
  53         struct list_head list;
  54 };
  55
  56 struct hiddev_list {
  57         struct hiddev_usage_ref buffer[HIDDEV_BUFFER_SIZE];
  58         int head;
  59         int tail;
  60         unsigned flags;
  61         struct fasync_struct *fasync;
  62         struct hiddev *hiddev;
  63         struct list_head node;
  64 };
  65
  66 static struct hiddev *hiddev_table[HIDDEV_MINORS];
  67
  68 /*
  69  * Find a report, given the report's type and ID.  The ID can be specified
  70  * indirectly by REPORT_ID_FIRST (which returns the first report of the given
  71  * type) or by (REPORT_ID_NEXT | old_id), which returns the next report of the
  72  * given type which follows old_id.
  73  */
  74 static struct hid_report *
  75 hiddev_lookup_report(struct hid_device *hid, struct hiddev_report_info *rinfo)
  76 {
  77         unsigned int flags = rinfo->report_id & ~HID_REPORT_ID_MASK;
  78         unsigned int rid = rinfo->report_id & HID_REPORT_ID_MASK;
  79         struct hid_report_enum *report_enum;
  80         struct hid_report *report;
  81         struct list_head *list;
  82
  83         if (rinfo->report_type < HID_REPORT_TYPE_MIN ||
  84             rinfo->report_type > HID_REPORT_TYPE_MAX)
  85                 return NULL;
  86
  87         report_enum = hid->report_enum +
  88                 (rinfo->report_type - HID_REPORT_TYPE_MIN);
  89
  90         switch (flags) {
  91         case 0: /* Nothing to do -- report_id is already set correctly */
  92                 break;
  93
  94         case HID_REPORT_ID_FIRST:
  95                 if (list_empty(&report_enum->report_list))
  96                         return NULL;
  97
  98                 list = report_enum->report_list.next;
  99                 report = list_entry(list, struct hid_report, list);
 100                 rinfo->report_id = report->id;
 101                 break;
 102
 103         case HID_REPORT_ID_NEXT:
 104                 report = report_enum->report_id_hash[rid];
 105                 if (!report)
 106                         return NULL;
 107
 108                 list = report->list.next;
 109                 if (list == &report_enum->report_list)
 110                         return NULL;
 111
 112                 report = list_entry(list, struct hid_report, list);
 113                 rinfo->report_id = report->id;
 114                 break;
 115
 116         default:
 117                 return NULL;
 118         }
 119
 120         return report_enum->report_id_hash[rinfo->report_id];
 121 }
 122
 123 /*
 124  * Perform an exhaustive search of the report table for a usage, given its
 125  * type and usage id.
 126  */
 127 static struct hid_field *
 128 hiddev_lookup_usage(struct hid_device *hid, struct hiddev_usage_ref *uref)
 129 {
 130         int i, j;
 131         struct hid_report *report;
 132         struct hid_report_enum *report_enum;
 133         struct hid_field *field;
 134
 135         if (uref->report_type < HID_REPORT_TYPE_MIN ||
 136             uref->report_type > HID_REPORT_TYPE_MAX)
 137                 return NULL;
 138
 139         report_enum = hid->report_enum +
 140                 (uref->report_type - HID_REPORT_TYPE_MIN);
 141
 142         list_for_each_entry(report, &report_enum->report_list, list) {
 143                 for (i = 0; i < report->maxfield; i++) {
 144                         field = report->field[i];
 145                         for (j = 0; j < field->maxusage; j++) {
 146                                 if (field->usage[j].hid == uref->usage_code) {
 147                                         uref->report_id = report->id;
 148                                         uref->field_index = i;
 149                                         uref->usage_index = j;
 150                                         return field;
 151                                 }
 152                         }
 153                 }
 154         }
 155
 156         return NULL;
 157 }
 158
 159 static void hiddev_send_event(struct hid_device *hid,
 160                               struct hiddev_usage_ref *uref)
 161 {
 162         struct hiddev *hiddev = hid->hiddev;
 163         struct hiddev_list *list;
 164
 165         list_for_each_entry(list, &hiddev->list, node) {
 166                 if (uref->field_index != HID_FIELD_INDEX_NONE ||
 167                     (list->flags & HIDDEV_FLAG_REPORT) != 0) {
 168                         list->buffer[list->head] = *uref;
 169                         list->head = (list->head + 1) &
 170                                 (HIDDEV_BUFFER_SIZE - 1);
 171                         kill_fasync(&list->fasync, SIGIO, POLL_IN);
 172                 }
 173         }
 174
 175         wake_up_interruptible(&hiddev->wait);
 176 }
 177
 178 /*
 179  * This is where hid.c calls into hiddev to pass an event that occurred over
 180  * the interrupt pipe
 181  */
 182 void hiddev_hid_event(struct hid_device *hid, struct hid_field *field,
 183                       struct hid_usage *usage, __s32 value)
 184 {
 185         unsigned type = field->report_type;
 186         struct hiddev_usage_ref uref;
 187
 188         uref.report_type =
 189           (type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
 190           ((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
 191            ((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE : 0));
 192         uref.report_id = field->report->id;
 193         uref.field_index = field->index;
 194         uref.usage_index = (usage - field->usage);
 195         uref.usage_code = usage->hid;
 196         uref.value = value;
 197
 198         hiddev_send_event(hid, &uref);
 199 }
 200 EXPORT_SYMBOL_GPL(hiddev_hid_event);
 201
 202 void hiddev_report_event(struct hid_device *hid, struct hid_report *report)
 203 {
 204         unsigned type = report->type;
 205         struct hiddev_usage_ref uref;
 206
 207         memset(&uref, 0, sizeof(uref));
 208         uref.report_type =
 209           (type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
 210           ((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
 211            ((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE : 0));
 212         uref.report_id = report->id;
 213         uref.field_index = HID_FIELD_INDEX_NONE;
 214
 215         hiddev_send_event(hid, &uref);
 216 }
 217 /*
 218  * fasync file op
 219  */
 220 static int hiddev_fasync(int fd, struct file *file, int on)
 221 {
 222         int retval;
 223         struct hiddev_list *list = file->private_data;
 224
 225         retval = fasync_helper(fd, file, on, &list->fasync);
 226
 227         return retval < 0 ? retval : 0;
 228 }
 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
 238         hiddev_fasync(-1, file, 0);
 239         list_del(&list->node);
 240
 241         if (!--list->hiddev->open) {
 242                 if (list->hiddev->exist)
 243                         usbhid_close(list->hiddev->hid);
 244                 else
 245                         kfree(list->hiddev);
 246         }
 247
 248         kfree(list);
 249
 250         return 0;
 251 }
 252
 253 /*
 254  * open file op
 255  */
 256 static int hiddev_open(struct inode *inode, struct file *file)
 257 {
 258         struct hiddev_list *list;
 259
 260         int i = iminor(inode) - HIDDEV_MINOR_BASE;
 261
 262         if (i >= HIDDEV_MINORS || !hiddev_table[i])
 263                 return -ENODEV;
 264
 265         if (!(list = kzalloc(sizeof(struct hiddev_list), GFP_KERNEL)))
 266                 return -ENOMEM;
 267
 268         list->hiddev = hiddev_table[i];
 269         list_add_tail(&list->node, &hiddev_table[i]->list);
 270         file->private_data = list;
 271
 272         if (!list->hiddev->open++)
 273                 if (list->hiddev->exist)
 274                         usbhid_open(hiddev_table[i]->hid);
 275
 276         return 0;
 277 }
 278
 279 /*
 280  * "write" file op
 281  */
 282 static ssize_t hiddev_write(struct file * file, const char __user * buffer, size_t count, loff_t *ppos)
 283 {
 284         return -EINVAL;
 285 }
 286
 287 /*
 288  * "read" file op
 289  */
 290 static ssize_t hiddev_read(struct file * file, char __user * buffer, size_t count, loff_t *ppos)
 291 {
 292         DECLARE_WAITQUEUE(wait, current);
 293         struct hiddev_list *list = file->private_data;
 294         int event_size;
 295         int retval = 0;
 296
 297         event_size = ((list->flags & HIDDEV_FLAG_UREF) != 0) ?
 298                 sizeof(struct hiddev_usage_ref) : sizeof(struct hiddev_event);
 299
 300         if (count < event_size)
 301                 return 0;
 302
 303         while (retval == 0) {
 304                 if (list->head == list->tail) {
 305                         add_wait_queue(&list->hiddev->wait, &wait);
 306                         set_current_state(TASK_INTERRUPTIBLE);
 307
 308                         while (list->head == list->tail) {
 309                                 if (file->f_flags & O_NONBLOCK) {
 310                                         retval = -EAGAIN;
 311                                         break;
 312                                 }
 313                                 if (signal_pending(current)) {
 314                                         retval = -ERESTARTSYS;
 315                                         break;
 316                                 }
 317                                 if (!list->hiddev->exist) {
 318                                         retval = -EIO;
 319                                         break;
 320                                 }
 321
 322                                 schedule();
 323                                 set_current_state(TASK_INTERRUPTIBLE);
 324                         }
 325
 326                         set_current_state(TASK_RUNNING);
 327                         remove_wait_queue(&list->hiddev->wait, &wait);
 328                 }
 329
 330                 if (retval)
 331                         return retval;
 332
 333
 334                 while (list->head != list->tail &&
 335                        retval + event_size <= count) {
 336                         if ((list->flags & HIDDEV_FLAG_UREF) == 0) {
 337                                 if (list->buffer[list->tail].field_index !=
 338                                     HID_FIELD_INDEX_NONE) {
 339                                         struct hiddev_event event;
 340                                         event.hid = list->buffer[list->tail].usage_code;
 341                                         event.value = list->buffer[list->tail].value;
 342                                         if (copy_to_user(buffer + retval, &event, sizeof(struct hiddev_event)))
 343                                                 return -EFAULT;
 344                                         retval += sizeof(struct hiddev_event);
 345                                 }
 346                         } else {
 347                                 if (list->buffer[list->tail].field_index != HID_FIELD_INDEX_NONE ||
 348                                     (list->flags & HIDDEV_FLAG_REPORT) != 0) {
 349                                         if (copy_to_user(buffer + retval, list->buffer + list->tail, sizeof(struct hiddev_usage_ref)))
 350                                                 return -EFAULT;
 351                                         retval += sizeof(struct hiddev_usage_ref);
 352                                 }
 353                         }
 354                         list->tail = (list->tail + 1) & (HIDDEV_BUFFER_SIZE - 1);
 355                 }
 356
 357         }
 358
 359         return retval;
 360 }
 361
 362 /*
 363  * "poll" file op
 364  * No kernel lock - fine
 365  */
 366 static unsigned int hiddev_poll(struct file *file, poll_table *wait)
 367 {
 368         struct hiddev_list *list = file->private_data;
 369
 370         poll_wait(file, &list->hiddev->wait, wait);
 371         if (list->head != list->tail)
 372                 return POLLIN | POLLRDNORM;
 373         if (!list->hiddev->exist)
 374                 return POLLERR | POLLHUP;
 375         return 0;
 376 }
 377
 378 /*
 379  * "ioctl" file op
 380  */
 381 static int hiddev_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
 382 {
 383         struct hiddev_list *list = file->private_data;
 384         struct hiddev *hiddev = list->hiddev;
 385         struct hid_device *hid = hiddev->hid;
 386         struct usb_device *dev = to_usb_device(hid->dev);
 387         struct hiddev_collection_info cinfo;
 388         struct hiddev_report_info rinfo;
 389         struct hiddev_field_info finfo;
 390         struct hiddev_usage_ref_multi *uref_multi = NULL;
 391         struct hiddev_usage_ref *uref;
 392         struct hiddev_devinfo dinfo;
 393         struct hid_report *report;
 394         struct hid_field *field;
 395         struct usbhid_device *usbhid = hid->driver_data;
 396         void __user *user_arg = (void __user *)arg;
 397         int i;
 398
 399         if (!hiddev->exist)
 400                 return -EIO;
 401
 402         switch (cmd) {
 403
 404         case HIDIOCGVERSION:
 405                 return put_user(HID_VERSION, (int __user *)arg);
 406
 407         case HIDIOCAPPLICATION:
 408                 if (arg < 0 || arg >= hid->maxapplication)
 409                         return -EINVAL;
 410
 411                 for (i = 0; i < hid->maxcollection; i++)
 412                         if (hid->collection[i].type ==
 413                             HID_COLLECTION_APPLICATION && arg-- == 0)
 414                                 break;
 415
 416                 if (i == hid->maxcollection)
 417                         return -EINVAL;
 418
 419                 return hid->collection[i].usage;
 420
 421         case HIDIOCGDEVINFO:
 422                 dinfo.bustype = BUS_USB;
 423                 dinfo.busnum = dev->bus->busnum;
 424                 dinfo.devnum = dev->devnum;
 425                 dinfo.ifnum = usbhid->ifnum;
 426                 dinfo.vendor = le16_to_cpu(dev->descriptor.idVendor);
 427                 dinfo.product = le16_to_cpu(dev->descriptor.idProduct);
 428                 dinfo.version = le16_to_cpu(dev->descriptor.bcdDevice);
 429                 dinfo.num_applications = hid->maxapplication;
 430                 if (copy_to_user(user_arg, &dinfo, sizeof(dinfo)))
 431                         return -EFAULT;
 432
 433                 return 0;
 434
 435         case HIDIOCGFLAG:
 436                 if (put_user(list->flags, (int __user *)arg))
 437                         return -EFAULT;
 438
 439                 return 0;
 440
 441         case HIDIOCSFLAG:
 442                 {
 443                         int newflags;
 444                         if (get_user(newflags, (int __user *)arg))
 445                                 return -EFAULT;
 446
 447                         if ((newflags & ~HIDDEV_FLAGS) != 0 ||
 448                             ((newflags & HIDDEV_FLAG_REPORT) != 0 &&
 449                              (newflags & HIDDEV_FLAG_UREF) == 0))
 450                                 return -EINVAL;
 451
 452                         list->flags = newflags;
 453
 454                         return 0;
 455                 }
 456
 457         case HIDIOCGSTRING:
 458                 {
 459                         int idx, len;
 460                         char *buf;
 461
 462                         if (get_user(idx, (int __user *)arg))
 463                                 return -EFAULT;
 464
 465                         if ((buf = kmalloc(HID_STRING_SIZE, GFP_KERNEL)) == NULL)
 466                                 return -ENOMEM;
 467
 468                         if ((len = usb_string(dev, idx, buf, HID_STRING_SIZE-1)) < 0) {
 469                                 kfree(buf);
 470                                 return -EINVAL;
 471                         }
 472
 473                         if (copy_to_user(user_arg+sizeof(int), buf, len+1)) {
 474                                 kfree(buf);
 475                                 return -EFAULT;
 476                         }
 477
 478                         kfree(buf);
 479
 480                         return len;
 481                 }
 482
 483         case HIDIOCINITREPORT:
 484                 usbhid_init_reports(hid);
 485
 486                 return 0;
 487
 488         case HIDIOCGREPORT:
 489                 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
 490                         return -EFAULT;
 491
 492                 if (rinfo.report_type == HID_REPORT_TYPE_OUTPUT)
 493                         return -EINVAL;
 494
 495                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 496                         return -EINVAL;
 497
 498                 usbhid_submit_report(hid, report, USB_DIR_IN);
 499                 usbhid_wait_io(hid);
 500
 501                 return 0;
 502
 503         case HIDIOCSREPORT:
 504                 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
 505                         return -EFAULT;
 506
 507                 if (rinfo.report_type == HID_REPORT_TYPE_INPUT)
 508                         return -EINVAL;
 509
 510                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 511                         return -EINVAL;
 512
 513                 usbhid_submit_report(hid, report, USB_DIR_OUT);
 514                 usbhid_wait_io(hid);
 515
 516                 return 0;
 517
 518         case HIDIOCGREPORTINFO:
 519                 if (copy_from_user(&rinfo, user_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(user_arg, &rinfo, sizeof(rinfo)))
 528                         return -EFAULT;
 529
 530                 return 0;
 531
 532         case HIDIOCGFIELDINFO:
 533                 if (copy_from_user(&finfo, user_arg, sizeof(finfo)))
 534                         return -EFAULT;
 535                 rinfo.report_type = finfo.report_type;
 536                 rinfo.report_id = finfo.report_id;
 537                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 538                         return -EINVAL;
 539
 540                 if (finfo.field_index >= report->maxfield)
 541                         return -EINVAL;
 542
 543                 field = report->field[finfo.field_index];
 544                 memset(&finfo, 0, sizeof(finfo));
 545                 finfo.report_type = rinfo.report_type;
 546                 finfo.report_id = rinfo.report_id;
 547                 finfo.field_index = field->report_count - 1;
 548                 finfo.maxusage = field->maxusage;
 549                 finfo.flags = field->flags;
 550                 finfo.physical = field->physical;
 551                 finfo.logical = field->logical;
 552                 finfo.application = field->application;
 553                 finfo.logical_minimum = field->logical_minimum;
 554                 finfo.logical_maximum = field->logical_maximum;
 555                 finfo.physical_minimum = field->physical_minimum;
 556                 finfo.physical_maximum = field->physical_maximum;
 557                 finfo.unit_exponent = field->unit_exponent;
 558                 finfo.unit = field->unit;
 559
 560                 if (copy_to_user(user_arg, &finfo, sizeof(finfo)))
 561                         return -EFAULT;
 562
 563                 return 0;
 564
 565         case HIDIOCGUCODE:
 566                 uref_multi = kmalloc(sizeof(struct hiddev_usage_ref_multi), GFP_KERNEL);
 567                 if (!uref_multi)
 568                         return -ENOMEM;
 569                 uref = &uref_multi->uref;
 570                 if (copy_from_user(uref, user_arg, sizeof(*uref)))
 571                         goto fault;
 572
 573                 rinfo.report_type = uref->report_type;
 574                 rinfo.report_id = uref->report_id;
 575                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 576                         goto inval;
 577
 578                 if (uref->field_index >= report->maxfield)
 579                         goto inval;
 580
 581                 field = report->field[uref->field_index];
 582                 if (uref->usage_index >= field->maxusage)
 583                         goto inval;
 584
 585                 uref->usage_code = field->usage[uref->usage_index].hid;
 586
 587                 if (copy_to_user(user_arg, uref, sizeof(*uref)))
 588                         goto fault;
 589
 590                 kfree(uref_multi);
 591                 return 0;
 592
 593         case HIDIOCGUSAGE:
 594         case HIDIOCSUSAGE:
 595         case HIDIOCGUSAGES:
 596         case HIDIOCSUSAGES:
 597         case HIDIOCGCOLLECTIONINDEX:
 598                 uref_multi = kmalloc(sizeof(struct hiddev_usage_ref_multi), GFP_KERNEL);
 599                 if (!uref_multi)
 600                         return -ENOMEM;
 601                 uref = &uref_multi->uref;
 602                 if (cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) {
 603                         if (copy_from_user(uref_multi, user_arg,
 604                                            sizeof(*uref_multi)))
 605                                 goto fault;
 606                 } else {
 607                         if (copy_from_user(uref, user_arg, sizeof(*uref)))
 608                                 goto fault;
 609                 }
 610
 611                 if (cmd != HIDIOCGUSAGE &&
 612                     cmd != HIDIOCGUSAGES &&
 613                     uref->report_type == HID_REPORT_TYPE_INPUT)
 614                         goto inval;
 615
 616                 if (uref->report_id == HID_REPORT_ID_UNKNOWN) {
 617                         field = hiddev_lookup_usage(hid, uref);
 618                         if (field == NULL)
 619                                 goto inval;
 620                 } else {
 621                         rinfo.report_type = uref->report_type;
 622                         rinfo.report_id = uref->report_id;
 623                         if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 624                                 goto inval;
 625
 626                         if (uref->field_index >= report->maxfield)
 627                                 goto inval;
 628
 629                         field = report->field[uref->field_index];
 630
 631                         if (cmd == HIDIOCGCOLLECTIONINDEX) {
 632                                 if (uref->usage_index >= field->maxusage)
 633                                         goto inval;
 634                         } else if (uref->usage_index >= field->report_count)
 635                                 goto inval;
 636
 637                         else if ((cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) &&
 638                                  (uref_multi->num_values > HID_MAX_MULTI_USAGES ||
 639                                   uref->usage_index + uref_multi->num_values > field->report_count))
 640                                 goto inval;
 641                         }
 642
 643                 switch (cmd) {
 644                         case HIDIOCGUSAGE:
 645                                 uref->value = field->value[uref->usage_index];
 646                                 if (copy_to_user(user_arg, uref, sizeof(*uref)))
 647                                         goto fault;
 648                                 goto goodreturn;
 649
 650                         case HIDIOCSUSAGE:
 651                                 field->value[uref->usage_index] = uref->value;
 652                                 goto goodreturn;
 653
 654                         case HIDIOCGCOLLECTIONINDEX:
 655                                 kfree(uref_multi);
 656                                 return field->usage[uref->usage_index].collection_index;
 657                         case HIDIOCGUSAGES:
 658                                 for (i = 0; i < uref_multi->num_values; i++)
 659                                         uref_multi->values[i] =
 660                                             field->value[uref->usage_index + i];
 661                                 if (copy_to_user(user_arg, uref_multi,
 662                                                  sizeof(*uref_multi)))
 663                                         goto fault;
 664                                 goto goodreturn;
 665                         case HIDIOCSUSAGES:
 666                                 for (i = 0; i < uref_multi->num_values; i++)
 667                                         field->value[uref->usage_index + i] =
 668                                             uref_multi->values[i];
 669                                 goto goodreturn;
 670                 }
 671
 672 goodreturn:
 673                 kfree(uref_multi);
 674                 return 0;
 675 fault:
 676                 kfree(uref_multi);
 677                 return -EFAULT;
 678 inval:
 679                 kfree(uref_multi);
 680                 return -EINVAL;
 681
 682         case HIDIOCGCOLLECTIONINFO:
 683                 if (copy_from_user(&cinfo, user_arg, sizeof(cinfo)))
 684                         return -EFAULT;
 685
 686                 if (cinfo.index >= hid->maxcollection)
 687                         return -EINVAL;
 688
 689                 cinfo.type = hid->collection[cinfo.index].type;
 690                 cinfo.usage = hid->collection[cinfo.index].usage;
 691                 cinfo.level = hid->collection[cinfo.index].level;
 692
 693                 if (copy_to_user(user_arg, &cinfo, sizeof(cinfo)))
 694                         return -EFAULT;
 695                 return 0;
 696
 697         default:
 698
 699                 if (_IOC_TYPE(cmd) != 'H' || _IOC_DIR(cmd) != _IOC_READ)
 700                         return -EINVAL;
 701
 702                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGNAME(0))) {
 703                         int len;
 704                         if (!hid->name)
 705                                 return 0;
 706                         len = strlen(hid->name) + 1;
 707                         if (len > _IOC_SIZE(cmd))
 708                                  len = _IOC_SIZE(cmd);
 709                         return copy_to_user(user_arg, hid->name, len) ?
 710                                 -EFAULT : len;
 711                 }
 712
 713                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGPHYS(0))) {
 714                         int len;
 715                         if (!hid->phys)
 716                                 return 0;
 717                         len = strlen(hid->phys) + 1;
 718                         if (len > _IOC_SIZE(cmd))
 719                                 len = _IOC_SIZE(cmd);
 720                         return copy_to_user(user_arg, hid->phys, len) ?
 721                                 -EFAULT : len;
 722                 }
 723         }
 724         return -EINVAL;
 725 }
 726
 727 static const struct file_operations hiddev_fops = {
 728         .owner =        THIS_MODULE,
 729         .read =         hiddev_read,
 730         .write =        hiddev_write,
 731         .poll =         hiddev_poll,
 732         .open =         hiddev_open,
 733         .release =      hiddev_release,
 734         .ioctl =        hiddev_ioctl,
 735         .fasync =       hiddev_fasync,
 736 };
 737
 738 static struct usb_class_driver hiddev_class = {
 739         .name =         "hiddev%d",
 740         .fops =         &hiddev_fops,
 741         .minor_base =   HIDDEV_MINOR_BASE,
 742 };
 743
 744 /*
 745  * This is where hid.c calls us to connect a hid device to the hiddev driver
 746  */
 747 int hiddev_connect(struct hid_device *hid)
 748 {
 749         struct hiddev *hiddev;
 750         struct usbhid_device *usbhid = hid->driver_data;
 751         int i;
 752         int retval;
 753
 754         for (i = 0; i < hid->maxcollection; i++)
 755                 if (hid->collection[i].type ==
 756                     HID_COLLECTION_APPLICATION &&
 757                     !IS_INPUT_APPLICATION(hid->collection[i].usage))
 758                         break;
 759
 760         if (i == hid->maxcollection && (hid->quirks & HID_QUIRK_HIDDEV) == 0)
 761                 return -1;
 762
 763         if (!(hiddev = kzalloc(sizeof(struct hiddev), GFP_KERNEL)))
 764                 return -1;
 765
 766         retval = usb_register_dev(usbhid->intf, &hiddev_class);
 767         if (retval) {
 768                 err("Not able to get a minor for this device.");
 769                 kfree(hiddev);
 770                 return -1;
 771         }
 772
 773         init_waitqueue_head(&hiddev->wait);
 774         INIT_LIST_HEAD(&hiddev->list);
 775         hiddev->hid = hid;
 776         hiddev->exist = 1;
 777
 778         hid->minor = usbhid->intf->minor;
 779         hid->hiddev = hiddev;
 780
 781         hiddev_table[usbhid->intf->minor - HIDDEV_MINOR_BASE] = hiddev;
 782
 783         return 0;
 784 }
 785
 786 /*
 787  * This is where hid.c calls us to disconnect a hiddev device from the
 788  * corresponding hid device (usually because the usb device has disconnected)
 789  */
 790 static struct usb_class_driver hiddev_class;
 791 void hiddev_disconnect(struct hid_device *hid)
 792 {
 793         struct hiddev *hiddev = hid->hiddev;
 794         struct usbhid_device *usbhid = hid->driver_data;
 795
 796         hiddev->exist = 0;
 797
 798         hiddev_table[hiddev->hid->minor - HIDDEV_MINOR_BASE] = NULL;
 799         usb_deregister_dev(usbhid->intf, &hiddev_class);
 800
 801         if (hiddev->open) {
 802                 usbhid_close(hiddev->hid);
 803                 wake_up_interruptible(&hiddev->wait);
 804         } else {
 805                 kfree(hiddev);
 806         }
 807 }
 808
 809 /* Currently this driver is a USB driver.  It's not a conventional one in
 810  * the sense that it doesn't probe at the USB level.  Instead it waits to
 811  * be connected by HID through the hiddev_connect / hiddev_disconnect
 812  * routines.  The reason to register as a USB device is to gain part of the
 813  * minor number space from the USB major.
 814  *
 815  * In theory, should the HID code be generalized to more than one physical
 816  * medium (say, IEEE 1384), this driver will probably need to register its
 817  * own major number, and in doing so, no longer need to register with USB.
 818  * At that point the probe routine and hiddev_driver struct below will no
 819  * longer be useful.
 820  */
 821
 822
 823 /* We never attach in this manner, and rely on HID to connect us.  This
 824  * is why there is no disconnect routine defined in the usb_driver either.
 825  */
 826 static int hiddev_usbd_probe(struct usb_interface *intf,
 827                              const struct usb_device_id *hiddev_info)
 828 {
 829         return -ENODEV;
 830 }
 831
 832
 833 static /* const */ struct usb_driver hiddev_driver = {
 834         .name =         "hiddev",
 835         .probe =        hiddev_usbd_probe,
 836 };
 837
 838 int __init hiddev_init(void)
 839 {
 840         return usb_register(&hiddev_driver);
 841 }
 842
 843 void hiddev_exit(void)
 844 {
 845         usb_deregister(&hiddev_driver);
 846 }