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