git.oblomov.eu Git - linux-2.6/blob - 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/config.h>
  29 #include <linux/poll.h>
  30 #include <linux/slab.h>
  31 #include <linux/module.h>
  32 #include <linux/init.h>
  33 #include <linux/smp_lock.h>
  34 #include <linux/input.h>
  35 #include <linux/usb.h>
  36 #include "hid.h"
  37 #include <linux/hiddev.h>
  38 #include <linux/devfs_fs_kernel.h>
  39
  40 #ifdef CONFIG_USB_DYNAMIC_MINORS
  41 #define HIDDEV_MINOR_BASE       0
  42 #define HIDDEV_MINORS           256
  43 #else
  44 #define HIDDEV_MINOR_BASE       96
  45 #define HIDDEV_MINORS           16
  46 #endif
  47 #define HIDDEV_BUFFER_SIZE      64
  48
  49 struct hiddev {
  50         int exist;
  51         int open;
  52         wait_queue_head_t wait;
  53         struct hid_device *hid;
  54         struct hiddev_list *list;
  55 };
  56
  57 struct hiddev_list {
  58         struct hiddev_usage_ref buffer[HIDDEV_BUFFER_SIZE];
  59         int head;
  60         int tail;
  61         unsigned flags;
  62         struct fasync_struct *fasync;
  63         struct hiddev *hiddev;
  64         struct hiddev_list *next;
  65 };
  66
  67 static struct hiddev *hiddev_table[HIDDEV_MINORS];
  68
  69 /*
  70  * Find a report, given the report's type and ID.  The ID can be specified
  71  * indirectly by REPORT_ID_FIRST (which returns the first report of the given
  72  * type) or by (REPORT_ID_NEXT | old_id), which returns the next report of the
  73  * given type which follows old_id.
  74  */
  75 static struct hid_report *
  76 hiddev_lookup_report(struct hid_device *hid, struct hiddev_report_info *rinfo)
  77 {
  78         unsigned flags = rinfo->report_id & ~HID_REPORT_ID_MASK;
  79         struct hid_report_enum *report_enum;
  80         struct list_head *list;
  81
  82         if (rinfo->report_type < HID_REPORT_TYPE_MIN ||
  83             rinfo->report_type > HID_REPORT_TYPE_MAX) return NULL;
  84
  85         report_enum = hid->report_enum +
  86                 (rinfo->report_type - HID_REPORT_TYPE_MIN);
  87
  88         switch (flags) {
  89         case 0: /* Nothing to do -- report_id is already set correctly */
  90                 break;
  91
  92         case HID_REPORT_ID_FIRST:
  93                 list = report_enum->report_list.next;
  94                 if (list == &report_enum->report_list)
  95                         return NULL;
  96                 rinfo->report_id = ((struct hid_report *) list)->id;
  97                 break;
  98
  99         case HID_REPORT_ID_NEXT:
 100                 list = (struct list_head *)
 101                         report_enum->report_id_hash[rinfo->report_id & HID_REPORT_ID_MASK];
 102                 if (list == NULL)
 103                         return NULL;
 104                 list = list->next;
 105                 if (list == &report_enum->report_list)
 106                         return NULL;
 107                 rinfo->report_id = ((struct hid_report *) list)->id;
 108                 break;
 109
 110         default:
 111                 return NULL;
 112         }
 113
 114         return report_enum->report_id_hash[rinfo->report_id];
 115 }
 116
 117 /*
 118  * Perform an exhaustive search of the report table for a usage, given its
 119  * type and usage id.
 120  */
 121 static struct hid_field *
 122 hiddev_lookup_usage(struct hid_device *hid, struct hiddev_usage_ref *uref)
 123 {
 124         int i, j;
 125         struct hid_report *report;
 126         struct hid_report_enum *report_enum;
 127         struct hid_field *field;
 128
 129         if (uref->report_type < HID_REPORT_TYPE_MIN ||
 130             uref->report_type > HID_REPORT_TYPE_MAX) return NULL;
 131
 132         report_enum = hid->report_enum +
 133                 (uref->report_type - HID_REPORT_TYPE_MIN);
 134
 135         list_for_each_entry(report, &report_enum->report_list, list)
 136                 for (i = 0; i < report->maxfield; i++) {
 137                         field = report->field[i];
 138                         for (j = 0; j < field->maxusage; j++) {
 139                                 if (field->usage[j].hid == uref->usage_code) {
 140                                         uref->report_id = report->id;
 141                                         uref->field_index = i;
 142                                         uref->usage_index = j;
 143                                         return field;
 144                                 }
 145                         }
 146                 }
 147
 148         return NULL;
 149 }
 150
 151 static void hiddev_send_event(struct hid_device *hid,
 152                               struct hiddev_usage_ref *uref)
 153 {
 154         struct hiddev *hiddev = hid->hiddev;
 155         struct hiddev_list *list = hiddev->list;
 156
 157         while (list) {
 158                 if (uref->field_index != HID_FIELD_INDEX_NONE ||
 159                     (list->flags & HIDDEV_FLAG_REPORT) != 0) {
 160                         list->buffer[list->head] = *uref;
 161                         list->head = (list->head + 1) &
 162                                 (HIDDEV_BUFFER_SIZE - 1);
 163                         kill_fasync(&list->fasync, SIGIO, POLL_IN);
 164                 }
 165
 166                 list = list->next;
 167         }
 168
 169         wake_up_interruptible(&hiddev->wait);
 170 }
 171
 172 /*
 173  * This is where hid.c calls into hiddev to pass an event that occurred over
 174  * the interrupt pipe
 175  */
 176 void hiddev_hid_event(struct hid_device *hid, struct hid_field *field,
 177                       struct hid_usage *usage, __s32 value, struct pt_regs *regs)
 178 {
 179         unsigned type = field->report_type;
 180         struct hiddev_usage_ref uref;
 181
 182         uref.report_type =
 183           (type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
 184           ((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
 185            ((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE:0));
 186         uref.report_id = field->report->id;
 187         uref.field_index = field->index;
 188         uref.usage_index = (usage - field->usage);
 189         uref.usage_code = usage->hid;
 190         uref.value = value;
 191
 192         hiddev_send_event(hid, &uref);
 193 }
 194
 195
 196 void hiddev_report_event(struct hid_device *hid, struct hid_report *report)
 197 {
 198         unsigned type = report->type;
 199         struct hiddev_usage_ref uref;
 200
 201         memset(&uref, 0, sizeof(uref));
 202         uref.report_type =
 203           (type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
 204           ((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
 205            ((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE:0));
 206         uref.report_id = report->id;
 207         uref.field_index = HID_FIELD_INDEX_NONE;
 208
 209         hiddev_send_event(hid, &uref);
 210 }
 211 /*
 212  * fasync file op
 213  */
 214 static int hiddev_fasync(int fd, struct file *file, int on)
 215 {
 216         int retval;
 217         struct hiddev_list *list = file->private_data;
 218         retval = fasync_helper(fd, file, on, &list->fasync);
 219         return retval < 0 ? retval : 0;
 220 }
 221
 222
 223 /*
 224  * release file op
 225  */
 226 static int hiddev_release(struct inode * inode, struct file * file)
 227 {
 228         struct hiddev_list *list = file->private_data;
 229         struct hiddev_list **listptr;
 230
 231         listptr = &list->hiddev->list;
 232         hiddev_fasync(-1, file, 0);
 233
 234         while (*listptr && (*listptr != list))
 235                 listptr = &((*listptr)->next);
 236         *listptr = (*listptr)->next;
 237
 238         if (!--list->hiddev->open) {
 239                 if (list->hiddev->exist)
 240                         hid_close(list->hiddev->hid);
 241                 else
 242                         kfree(list->hiddev);
 243         }
 244
 245         kfree(list);
 246
 247         return 0;
 248 }
 249
 250 /*
 251  * open file op
 252  */
 253 static int hiddev_open(struct inode * inode, struct file * file) {
 254         struct hiddev_list *list;
 255
 256         int i = iminor(inode) - HIDDEV_MINOR_BASE;
 257
 258         if (i >= HIDDEV_MINORS || !hiddev_table[i])
 259                 return -ENODEV;
 260
 261         if (!(list = kmalloc(sizeof(struct hiddev_list), GFP_KERNEL)))
 262                 return -ENOMEM;
 263         memset(list, 0, sizeof(struct hiddev_list));
 264
 265         list->hiddev = hiddev_table[i];
 266         list->next = hiddev_table[i]->list;
 267         hiddev_table[i]->list = list;
 268
 269         file->private_data = list;
 270
 271         if (!list->hiddev->open++)
 272                 if (list->hiddev->exist)
 273                         hid_open(hiddev_table[i]->hid);
 274
 275         return 0;
 276 }
 277
 278 /*
 279  * "write" file op
 280  */
 281 static ssize_t hiddev_write(struct file * file, const char __user * buffer, size_t count, loff_t *ppos)
 282 {
 283         return -EINVAL;
 284 }
 285
 286 /*
 287  * "read" file op
 288  */
 289 static ssize_t hiddev_read(struct file * file, char __user * buffer, size_t count, loff_t *ppos)
 290 {
 291         DECLARE_WAITQUEUE(wait, current);
 292         struct hiddev_list *list = file->private_data;
 293         int event_size;
 294         int retval = 0;
 295
 296         event_size = ((list->flags & HIDDEV_FLAG_UREF) != 0) ?
 297                 sizeof(struct hiddev_usage_ref) : sizeof(struct hiddev_event);
 298
 299         if (count < event_size)
 300                 return 0;
 301
 302         while (retval == 0) {
 303                 if (list->head == list->tail) {
 304                         add_wait_queue(&list->hiddev->wait, &wait);
 305                         set_current_state(TASK_INTERRUPTIBLE);
 306
 307                         while (list->head == list->tail) {
 308                                 if (file->f_flags & O_NONBLOCK) {
 309                                         retval = -EAGAIN;
 310                                         break;
 311                                 }
 312                                 if (signal_pending(current)) {
 313                                         retval = -ERESTARTSYS;
 314                                         break;
 315                                 }
 316                                 if (!list->hiddev->exist) {
 317                                         retval = -EIO;
 318                                         break;
 319                                 }
 320
 321                                 schedule();
 322                         }
 323
 324                         set_current_state(TASK_RUNNING);
 325                         remove_wait_queue(&list->hiddev->wait, &wait);
 326                 }
 327
 328                 if (retval)
 329                         return retval;
 330
 331
 332                 while (list->head != list->tail &&
 333                        retval + event_size <= count) {
 334                         if ((list->flags & HIDDEV_FLAG_UREF) == 0) {
 335                                 if (list->buffer[list->tail].field_index !=
 336                                     HID_FIELD_INDEX_NONE) {
 337                                         struct hiddev_event event;
 338                                         event.hid = list->buffer[list->tail].usage_code;
 339                                         event.value = list->buffer[list->tail].value;
 340                                         if (copy_to_user(buffer + retval, &event, sizeof(struct hiddev_event)))
 341                                                 return -EFAULT;
 342                                         retval += sizeof(struct hiddev_event);
 343                                 }
 344                         } else {
 345                                 if (list->buffer[list->tail].field_index != HID_FIELD_INDEX_NONE ||
 346                                     (list->flags & HIDDEV_FLAG_REPORT) != 0) {
 347                                         if (copy_to_user(buffer + retval, list->buffer + list->tail, sizeof(struct hiddev_usage_ref)))
 348                                                 return -EFAULT;
 349                                         retval += sizeof(struct hiddev_usage_ref);
 350                                 }
 351                         }
 352                         list->tail = (list->tail + 1) & (HIDDEV_BUFFER_SIZE - 1);
 353                 }
 354
 355         }
 356
 357         return retval;
 358 }
 359
 360 /*
 361  * "poll" file op
 362  * No kernel lock - fine
 363  */
 364 static unsigned int hiddev_poll(struct file *file, poll_table *wait)
 365 {
 366         struct hiddev_list *list = file->private_data;
 367         poll_wait(file, &list->hiddev->wait, wait);
 368         if (list->head != list->tail)
 369                 return POLLIN | POLLRDNORM;
 370         if (!list->hiddev->exist)
 371                 return POLLERR | POLLHUP;
 372         return 0;
 373 }
 374
 375 /*
 376  * "ioctl" file op
 377  */
 378 static int hiddev_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
 379 {
 380         struct hiddev_list *list = file->private_data;
 381         struct hiddev *hiddev = list->hiddev;
 382         struct hid_device *hid = hiddev->hid;
 383         struct usb_device *dev = hid->dev;
 384         struct hiddev_collection_info cinfo;
 385         struct hiddev_report_info rinfo;
 386         struct hiddev_field_info finfo;
 387         struct hiddev_usage_ref_multi *uref_multi=NULL;
 388         struct hiddev_usage_ref *uref;
 389         struct hiddev_devinfo dinfo;
 390         struct hid_report *report;
 391         struct hid_field *field;
 392         void __user *user_arg = (void __user *)arg;
 393         int i;
 394
 395         if (!hiddev->exist)
 396                 return -EIO;
 397
 398         switch (cmd) {
 399
 400         case HIDIOCGVERSION:
 401                 return put_user(HID_VERSION, (int __user *)arg);
 402
 403         case HIDIOCAPPLICATION:
 404                 if (arg < 0 || arg >= hid->maxapplication)
 405                         return -EINVAL;
 406
 407                 for (i = 0; i < hid->maxcollection; i++)
 408                         if (hid->collection[i].type ==
 409                             HID_COLLECTION_APPLICATION && arg-- == 0)
 410                                 break;
 411
 412                 if (i == hid->maxcollection)
 413                         return -EINVAL;
 414
 415                 return hid->collection[i].usage;
 416
 417         case HIDIOCGDEVINFO:
 418                 dinfo.bustype = BUS_USB;
 419                 dinfo.busnum = dev->bus->busnum;
 420                 dinfo.devnum = dev->devnum;
 421                 dinfo.ifnum = hid->ifnum;
 422                 dinfo.vendor = le16_to_cpu(dev->descriptor.idVendor);
 423                 dinfo.product = le16_to_cpu(dev->descriptor.idProduct);
 424                 dinfo.version = le16_to_cpu(dev->descriptor.bcdDevice);
 425                 dinfo.num_applications = hid->maxapplication;
 426                 if (copy_to_user(user_arg, &dinfo, sizeof(dinfo)))
 427                         return -EFAULT;
 428
 429                 return 0;
 430
 431         case HIDIOCGFLAG:
 432                 if (put_user(list->flags, (int __user *)arg))
 433                         return -EFAULT;
 434
 435                 return 0;
 436
 437         case HIDIOCSFLAG:
 438                 {
 439                         int newflags;
 440                         if (get_user(newflags, (int __user *)arg))
 441                                 return -EFAULT;
 442
 443                         if ((newflags & ~HIDDEV_FLAGS) != 0 ||
 444                             ((newflags & HIDDEV_FLAG_REPORT) != 0 &&
 445                              (newflags & HIDDEV_FLAG_UREF) == 0))
 446                                 return -EINVAL;
 447
 448                         list->flags = newflags;
 449
 450                         return 0;
 451                 }
 452
 453         case HIDIOCGSTRING:
 454                 {
 455                         int idx, len;
 456                         char *buf;
 457
 458                         if (get_user(idx, (int __user *)arg))
 459                                 return -EFAULT;
 460
 461                         if ((buf = kmalloc(HID_STRING_SIZE, GFP_KERNEL)) == NULL)
 462                                 return -ENOMEM;
 463
 464                         if ((len = usb_string(dev, idx, buf, HID_STRING_SIZE-1)) < 0) {
 465                                 kfree(buf);
 466                                 return -EINVAL;
 467                         }
 468
 469                         if (copy_to_user(user_arg+sizeof(int), buf, len+1)) {
 470                                 kfree(buf);
 471                                 return -EFAULT;
 472                         }
 473
 474                         kfree(buf);
 475
 476                         return len;
 477                 }
 478
 479         case HIDIOCINITREPORT:
 480                 hid_init_reports(hid);
 481
 482                 return 0;
 483
 484         case HIDIOCGREPORT:
 485                 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
 486                         return -EFAULT;
 487
 488                 if (rinfo.report_type == HID_REPORT_TYPE_OUTPUT)
 489                         return -EINVAL;
 490
 491                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 492                         return -EINVAL;
 493
 494                 hid_submit_report(hid, report, USB_DIR_IN);
 495                 hid_wait_io(hid);
 496
 497                 return 0;
 498
 499         case HIDIOCSREPORT:
 500                 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
 501                         return -EFAULT;
 502
 503                 if (rinfo.report_type == HID_REPORT_TYPE_INPUT)
 504                         return -EINVAL;
 505
 506                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 507                         return -EINVAL;
 508
 509                 hid_submit_report(hid, report, USB_DIR_OUT);
 510
 511                 return 0;
 512
 513         case HIDIOCGREPORTINFO:
 514                 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
 515                         return -EFAULT;
 516
 517                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 518                         return -EINVAL;
 519
 520                 rinfo.num_fields = report->maxfield;
 521
 522                 if (copy_to_user(user_arg, &rinfo, sizeof(rinfo)))
 523                         return -EFAULT;
 524
 525                 return 0;
 526
 527         case HIDIOCGFIELDINFO:
 528                 if (copy_from_user(&finfo, user_arg, sizeof(finfo)))
 529                         return -EFAULT;
 530                 rinfo.report_type = finfo.report_type;
 531                 rinfo.report_id = finfo.report_id;
 532                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 533                         return -EINVAL;
 534
 535                 if (finfo.field_index >= report->maxfield)
 536                         return -EINVAL;
 537
 538                 field = report->field[finfo.field_index];
 539                 memset(&finfo, 0, sizeof(finfo));
 540                 finfo.report_type = rinfo.report_type;
 541                 finfo.report_id = rinfo.report_id;
 542                 finfo.field_index = field->report_count - 1;
 543                 finfo.maxusage = field->maxusage;
 544                 finfo.flags = field->flags;
 545                 finfo.physical = field->physical;
 546                 finfo.logical = field->logical;
 547                 finfo.application = field->application;
 548                 finfo.logical_minimum = field->logical_minimum;
 549                 finfo.logical_maximum = field->logical_maximum;
 550                 finfo.physical_minimum = field->physical_minimum;
 551                 finfo.physical_maximum = field->physical_maximum;
 552                 finfo.unit_exponent = field->unit_exponent;
 553                 finfo.unit = field->unit;
 554
 555                 if (copy_to_user(user_arg, &finfo, sizeof(finfo)))
 556                         return -EFAULT;
 557
 558                 return 0;
 559
 560         case HIDIOCGUCODE:
 561                 uref_multi = kmalloc(sizeof(struct hiddev_usage_ref_multi), GFP_KERNEL);
 562                 if (!uref_multi)
 563                         return -ENOMEM;
 564                 uref = &uref_multi->uref;
 565                 if (copy_from_user(uref, user_arg, sizeof(*uref)))
 566                         goto fault;
 567
 568                 rinfo.report_type = uref->report_type;
 569                 rinfo.report_id = uref->report_id;
 570                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 571                         goto inval;
 572
 573                 if (uref->field_index >= report->maxfield)
 574                         goto inval;
 575
 576                 field = report->field[uref->field_index];
 577                 if (uref->usage_index >= field->maxusage)
 578                         goto inval;
 579
 580                 uref->usage_code = field->usage[uref->usage_index].hid;
 581
 582                 if (copy_to_user(user_arg, uref, sizeof(*uref)))
 583                         goto fault;
 584
 585                 kfree(uref_multi);
 586                 return 0;
 587
 588         case HIDIOCGUSAGE:
 589         case HIDIOCSUSAGE:
 590         case HIDIOCGUSAGES:
 591         case HIDIOCSUSAGES:
 592         case HIDIOCGCOLLECTIONINDEX:
 593                 uref_multi = kmalloc(sizeof(struct hiddev_usage_ref_multi), GFP_KERNEL);
 594                 if (!uref_multi)
 595                         return -ENOMEM;
 596                 uref = &uref_multi->uref;
 597                 if (cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) {
 598                         if (copy_from_user(uref_multi, user_arg,
 599                                            sizeof(*uref_multi)))
 600                                 goto fault;
 601                 } else {
 602                         if (copy_from_user(uref, user_arg, sizeof(*uref)))
 603                                 goto fault;
 604                 }
 605
 606                 if (cmd != HIDIOCGUSAGE &&
 607                     cmd != HIDIOCGUSAGES &&
 608                     uref->report_type == HID_REPORT_TYPE_INPUT)
 609                         goto inval;
 610
 611                 if (uref->report_id == HID_REPORT_ID_UNKNOWN) {
 612                         field = hiddev_lookup_usage(hid, uref);
 613                         if (field == NULL)
 614                                 goto inval;
 615                 } else {
 616                         rinfo.report_type = uref->report_type;
 617                         rinfo.report_id = uref->report_id;
 618                         if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 619                                 goto inval;
 620
 621                         if (uref->field_index >= report->maxfield)
 622                                 goto inval;
 623
 624                         field = report->field[uref->field_index];
 625
 626                         if (cmd == HIDIOCGCOLLECTIONINDEX) {
 627                                 if (uref->usage_index >= field->maxusage)
 628                                         goto inval;
 629                         } else if (uref->usage_index >= field->report_count)
 630                                 goto inval;
 631
 632                         else if ((cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) &&
 633                                  (uref_multi->num_values > HID_MAX_MULTI_USAGES ||
 634                                   uref->usage_index + uref_multi->num_values >= field->report_count))
 635                                 goto inval;
 636                         }
 637
 638                 switch (cmd) {
 639                         case HIDIOCGUSAGE:
 640                                 uref->value = field->value[uref->usage_index];
 641                                 if (copy_to_user(user_arg, uref, sizeof(*uref)))
 642                                         goto fault;
 643                                 goto goodreturn;
 644
 645                         case HIDIOCSUSAGE:
 646                                 field->value[uref->usage_index] = uref->value;
 647                                 goto goodreturn;
 648
 649                         case HIDIOCGCOLLECTIONINDEX:
 650                                 kfree(uref_multi);
 651                                 return field->usage[uref->usage_index].collection_index;
 652                         case HIDIOCGUSAGES:
 653                                 for (i = 0; i < uref_multi->num_values; i++)
 654                                         uref_multi->values[i] =
 655                                             field->value[uref->usage_index + i];
 656                                 if (copy_to_user(user_arg, uref_multi,
 657                                                  sizeof(*uref_multi)))
 658                                         goto fault;
 659                                 goto goodreturn;
 660                         case HIDIOCSUSAGES:
 661                                 for (i = 0; i < uref_multi->num_values; i++)
 662                                         field->value[uref->usage_index + i] =
 663                                             uref_multi->values[i];
 664                                 goto goodreturn;
 665                 }
 666
 667 goodreturn:
 668                 kfree(uref_multi);
 669                 return 0;
 670 fault:
 671                 kfree(uref_multi);
 672                 return -EFAULT;
 673 inval:
 674                 kfree(uref_multi);
 675                 return -EINVAL;
 676
 677         case HIDIOCGCOLLECTIONINFO:
 678                 if (copy_from_user(&cinfo, user_arg, sizeof(cinfo)))
 679                         return -EFAULT;
 680
 681                 if (cinfo.index >= hid->maxcollection)
 682                         return -EINVAL;
 683
 684                 cinfo.type = hid->collection[cinfo.index].type;
 685                 cinfo.usage = hid->collection[cinfo.index].usage;
 686                 cinfo.level = hid->collection[cinfo.index].level;
 687
 688                 if (copy_to_user(user_arg, &cinfo, sizeof(cinfo)))
 689                         return -EFAULT;
 690                 return 0;
 691
 692         default:
 693
 694                 if (_IOC_TYPE(cmd) != 'H' || _IOC_DIR(cmd) != _IOC_READ)
 695                         return -EINVAL;
 696
 697                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGNAME(0))) {
 698                         int len;
 699                         if (!hid->name)
 700                                 return 0;
 701                         len = strlen(hid->name) + 1;
 702                         if (len > _IOC_SIZE(cmd))
 703                                  len = _IOC_SIZE(cmd);
 704                         return copy_to_user(user_arg, hid->name, len) ?
 705                                 -EFAULT : len;
 706                 }
 707
 708                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGPHYS(0))) {
 709                         int len;
 710                         if (!hid->phys)
 711                                 return 0;
 712                         len = strlen(hid->phys) + 1;
 713                         if (len > _IOC_SIZE(cmd))
 714                                 len = _IOC_SIZE(cmd);
 715                         return copy_to_user(user_arg, hid->phys, len) ?
 716                                 -EFAULT : len;
 717                 }
 718         }
 719         return -EINVAL;
 720 }
 721
 722 static struct file_operations hiddev_fops = {
 723         .owner =        THIS_MODULE,
 724         .read =         hiddev_read,
 725         .write =        hiddev_write,
 726         .poll =         hiddev_poll,
 727         .open =         hiddev_open,
 728         .release =      hiddev_release,
 729         .ioctl =        hiddev_ioctl,
 730         .fasync =       hiddev_fasync,
 731 };
 732
 733 static struct usb_class_driver hiddev_class = {
 734         .name =         "usb/hid/hiddev%d",
 735         .fops =         &hiddev_fops,
 736         .mode =         S_IFCHR | S_IRUGO | S_IWUSR,
 737         .minor_base =   HIDDEV_MINOR_BASE,
 738 };
 739
 740 /*
 741  * This is where hid.c calls us to connect a hid device to the hiddev driver
 742  */
 743 int hiddev_connect(struct hid_device *hid)
 744 {
 745         struct hiddev *hiddev;
 746         int i;
 747         int retval;
 748
 749         for (i = 0; i < hid->maxcollection; i++)
 750                 if (hid->collection[i].type ==
 751                     HID_COLLECTION_APPLICATION &&
 752                     !IS_INPUT_APPLICATION(hid->collection[i].usage))
 753                         break;
 754
 755         if (i == hid->maxcollection && (hid->quirks & HID_QUIRK_HIDDEV) == 0)
 756                 return -1;
 757
 758         if (!(hiddev = kmalloc(sizeof(struct hiddev), GFP_KERNEL)))
 759                 return -1;
 760         memset(hiddev, 0, sizeof(struct hiddev));
 761
 762         retval = usb_register_dev(hid->intf, &hiddev_class);
 763         if (retval) {
 764                 err("Not able to get a minor for this device.");
 765                 kfree(hiddev);
 766                 return -1;
 767         }
 768
 769         init_waitqueue_head(&hiddev->wait);
 770
 771         hiddev_table[hid->intf->minor - HIDDEV_MINOR_BASE] = hiddev;
 772
 773         hiddev->hid = hid;
 774         hiddev->exist = 1;
 775
 776         hid->minor = hid->intf->minor;
 777         hid->hiddev = hiddev;
 778
 779         return 0;
 780 }
 781
 782 /*
 783  * This is where hid.c calls us to disconnect a hiddev device from the
 784  * corresponding hid device (usually because the usb device has disconnected)
 785  */
 786 static struct usb_class_driver hiddev_class;
 787 void hiddev_disconnect(struct hid_device *hid)
 788 {
 789         struct hiddev *hiddev = hid->hiddev;
 790
 791         hiddev->exist = 0;
 792
 793         hiddev_table[hiddev->hid->minor - HIDDEV_MINOR_BASE] = NULL;
 794         usb_deregister_dev(hiddev->hid->intf, &hiddev_class);
 795
 796         if (hiddev->open) {
 797                 hid_close(hiddev->hid);
 798                 wake_up_interruptible(&hiddev->wait);
 799         } else {
 800                 kfree(hiddev);
 801         }
 802 }
 803
 804 /* Currently this driver is a USB driver.  It's not a conventional one in
 805  * the sense that it doesn't probe at the USB level.  Instead it waits to
 806  * be connected by HID through the hiddev_connect / hiddev_disconnect
 807  * routines.  The reason to register as a USB device is to gain part of the
 808  * minor number space from the USB major.
 809  *
 810  * In theory, should the HID code be generalized to more than one physical
 811  * medium (say, IEEE 1384), this driver will probably need to register its
 812  * own major number, and in doing so, no longer need to register with USB.
 813  * At that point the probe routine and hiddev_driver struct below will no
 814  * longer be useful.
 815  */
 816
 817
 818 /* We never attach in this manner, and rely on HID to connect us.  This
 819  * is why there is no disconnect routine defined in the usb_driver either.
 820  */
 821 static int hiddev_usbd_probe(struct usb_interface *intf,
 822                              const struct usb_device_id *hiddev_info)
 823 {
 824         return -ENODEV;
 825 }
 826
 827
 828 static /* const */ struct usb_driver hiddev_driver = {
 829         .owner =        THIS_MODULE,
 830         .name =         "hiddev",
 831         .probe =        hiddev_usbd_probe,
 832 };
 833
 834 int __init hiddev_init(void)
 835 {
 836         devfs_mk_dir("usb/hid");
 837         return usb_register(&hiddev_driver);
 838 }
 839
 840 void hiddev_exit(void)
 841 {
 842         usb_deregister(&hiddev_driver);
 843         devfs_remove("usb/hid");
 844 }