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