drivers/hid/usbhid/hiddev.c

   1 /*
   2  *  Copyright (c) 2001 Paul Stewart
   3  *  Copyright (c) 2001 Vojtech Pavlik
   4  *
   5  *  HID char devices, giving access to raw HID device events.
   6  *
   7  */
   8
   9 /*
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  23  *
  24  * Should you need to contact me, the author, you can do so either by
  25  * e-mail - mail your message to Paul Stewart <stewart@wetlogic.net>
  26  */
  27
  28 #include <linux/poll.h>
  29 #include <linux/slab.h>
  30 #include <linux/module.h>
  31 #include <linux/init.h>
  32 #include <linux/smp_lock.h>
  33 #include <linux/input.h>
  34 #include <linux/usb.h>
  35 #include <linux/hid.h>
  36 #include <linux/hiddev.h>
  37 #include "usbhid.h"
  38
  39 #ifdef CONFIG_USB_DYNAMIC_MINORS
  40 #define HIDDEV_MINOR_BASE       0
  41 #define HIDDEV_MINORS           256
  42 #else
  43 #define HIDDEV_MINOR_BASE       96
  44 #define HIDDEV_MINORS           16
  45 #endif
  46 #define HIDDEV_BUFFER_SIZE      64
  47
  48 struct hiddev {
  49         int exist;
  50         int open;
  51         wait_queue_head_t wait;
  52         struct hid_device *hid;
  53         struct list_head list;
  54 };
  55
  56 struct hiddev_list {
  57         struct hiddev_usage_ref buffer[HIDDEV_BUFFER_SIZE];
  58         int head;
  59         int tail;
  60         unsigned flags;
  61         struct fasync_struct *fasync;
  62         struct hiddev *hiddev;
  63         struct list_head node;
  64 };
  65
  66 static struct hiddev *hiddev_table[HIDDEV_MINORS];
  67
  68 /*
  69  * Find a report, given the report's type and ID.  The ID can be specified
  70  * indirectly by REPORT_ID_FIRST (which returns the first report of the given
  71  * type) or by (REPORT_ID_NEXT | old_id), which returns the next report of the
  72  * given type which follows old_id.
  73  */
  74 static struct hid_report *
  75 hiddev_lookup_report(struct hid_device *hid, struct hiddev_report_info *rinfo)
  76 {
  77         unsigned int flags = rinfo->report_id & ~HID_REPORT_ID_MASK;
  78         unsigned int rid = rinfo->report_id & HID_REPORT_ID_MASK;
  79         struct hid_report_enum *report_enum;
  80         struct hid_report *report;
  81         struct list_head *list;
  82
  83         if (rinfo->report_type < HID_REPORT_TYPE_MIN ||
  84             rinfo->report_type > HID_REPORT_TYPE_MAX)
  85                 return NULL;
  86
  87         report_enum = hid->report_enum +
  88                 (rinfo->report_type - HID_REPORT_TYPE_MIN);
  89
  90         switch (flags) {
  91         case 0: /* Nothing to do -- report_id is already set correctly */
  92                 break;
  93
  94         case HID_REPORT_ID_FIRST:
  95                 if (list_empty(&report_enum->report_list))
  96                         return NULL;
  97
  98                 list = report_enum->report_list.next;
  99                 report = list_entry(list, struct hid_report, list);
 100                 rinfo->report_id = report->id;
 101                 break;
 102
 103         case HID_REPORT_ID_NEXT:
 104                 report = report_enum->report_id_hash[rid];
 105                 if (!report)
 106                         return NULL;
 107
 108                 list = report->list.next;
 109                 if (list == &report_enum->report_list)
 110                         return NULL;
 111
 112                 report = list_entry(list, struct hid_report, list);
 113                 rinfo->report_id = report->id;
 114                 break;
 115
 116         default:
 117                 return NULL;
 118         }
 119
 120         return report_enum->report_id_hash[rinfo->report_id];
 121 }
 122
 123 /*
 124  * Perform an exhaustive search of the report table for a usage, given its
 125  * type and usage id.
 126  */
 127 static struct hid_field *
 128 hiddev_lookup_usage(struct hid_device *hid, struct hiddev_usage_ref *uref)
 129 {
 130         int i, j;
 131         struct hid_report *report;
 132         struct hid_report_enum *report_enum;
 133         struct hid_field *field;
 134
 135         if (uref->report_type < HID_REPORT_TYPE_MIN ||
 136             uref->report_type > HID_REPORT_TYPE_MAX)
 137                 return NULL;
 138
 139         report_enum = hid->report_enum +
 140                 (uref->report_type - HID_REPORT_TYPE_MIN);
 141
 142         list_for_each_entry(report, &report_enum->report_list, list) {
 143                 for (i = 0; i < report->maxfield; i++) {
 144                         field = report->field[i];
 145                         for (j = 0; j < field->maxusage; j++) {
 146                                 if (field->usage[j].hid == uref->usage_code) {
 147                                         uref->report_id = report->id;
 148                                         uref->field_index = i;
 149                                         uref->usage_index = j;
 150                                         return field;
 151                                 }
 152                         }
 153                 }
 154         }
 155
 156         return NULL;
 157 }
 158
 159 static void hiddev_send_event(struct hid_device *hid,
 160                               struct hiddev_usage_ref *uref)
 161 {
 162         struct hiddev *hiddev = hid->hiddev;
 163         struct hiddev_list *list;
 164
 165         list_for_each_entry(list, &hiddev->list, node) {
 166                 if (uref->field_index != HID_FIELD_INDEX_NONE ||
 167                     (list->flags & HIDDEV_FLAG_REPORT) != 0) {
 168                         list->buffer[list->head] = *uref;
 169                         list->head = (list->head + 1) &
 170                                 (HIDDEV_BUFFER_SIZE - 1);
 171                         kill_fasync(&list->fasync, SIGIO, POLL_IN);
 172                 }
 173         }
 174
 175         wake_up_interruptible(&hiddev->wait);
 176 }
 177
 178 /*
 179  * This is where hid.c calls into hiddev to pass an event that occurred over
 180  * the interrupt pipe
 181  */
 182 void hiddev_hid_event(struct hid_device *hid, struct hid_field *field,
 183                       struct hid_usage *usage, __s32 value)
 184 {
 185         unsigned type = field->report_type;
 186         struct hiddev_usage_ref uref;
 187
 188         uref.report_type =
 189           (type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
 190           ((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
 191            ((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE : 0));
 192         uref.report_id = field->report->id;
 193         uref.field_index = field->index;
 194         uref.usage_index = (usage - field->usage);
 195         uref.usage_code = usage->hid;
 196         uref.value = value;
 197
 198         hiddev_send_event(hid, &uref);
 199 }
 200 EXPORT_SYMBOL_GPL(hiddev_hid_event);
 201
 202 void hiddev_report_event(struct hid_device *hid, struct hid_report *report)
 203 {
 204         unsigned type = report->type;
 205         struct hiddev_usage_ref uref;
 206
 207         memset(&uref, 0, sizeof(uref));
 208         uref.report_type =
 209           (type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
 210           ((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
 211            ((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE : 0));
 212         uref.report_id = report->id;
 213         uref.field_index = HID_FIELD_INDEX_NONE;
 214
 215         hiddev_send_event(hid, &uref);
 216 }
 217
 218 /*
 219  * fasync file op
 220  */
 221 static int hiddev_fasync(int fd, struct file *file, int on)
 222 {
 223         int retval;
 224         struct hiddev_list *list = file->private_data;
 225
 226         retval = fasync_helper(fd, file, on, &list->fasync);
 227
 228         return retval < 0 ? retval : 0;
 229 }
 230
 231
 232 /*
 233  * release file op
 234  */
 235 static int hiddev_release(struct inode * inode, struct file * file)
 236 {
 237         struct hiddev_list *list = file->private_data;
 238
 239         hiddev_fasync(-1, file, 0);
 240         list_del(&list->node);
 241
 242         if (!--list->hiddev->open) {
 243                 if (list->hiddev->exist)
 244                         usbhid_close(list->hiddev->hid);
 245                 else
 246                         kfree(list->hiddev);
 247         }
 248
 249         kfree(list);
 250
 251         return 0;
 252 }
 253
 254 /*
 255  * open file op
 256  */
 257 static int hiddev_open(struct inode *inode, struct file *file)
 258 {
 259         struct hiddev_list *list;
 260
 261         int i = iminor(inode) - HIDDEV_MINOR_BASE;
 262
 263         if (i >= HIDDEV_MINORS || !hiddev_table[i])
 264                 return -ENODEV;
 265
 266         if (!(list = kzalloc(sizeof(struct hiddev_list), GFP_KERNEL)))
 267                 return -ENOMEM;
 268
 269         list->hiddev = hiddev_table[i];
 270         list_add_tail(&list->node, &hiddev_table[i]->list);
 271         file->private_data = list;
 272
 273         if (!list->hiddev->open++)
 274                 if (list->hiddev->exist)
 275                         usbhid_open(hiddev_table[i]->hid);
 276
 277         return 0;
 278 }
 279
 280 /*
 281  * "write" file op
 282  */
 283 static ssize_t hiddev_write(struct file * file, const char __user * buffer, size_t count, loff_t *ppos)
 284 {
 285         return -EINVAL;
 286 }
 287
 288 /*
 289  * "read" file op
 290  */
 291 static ssize_t hiddev_read(struct file * file, char __user * buffer, size_t count, loff_t *ppos)
 292 {
 293         DECLARE_WAITQUEUE(wait, current);
 294         struct hiddev_list *list = file->private_data;
 295         int event_size;
 296         int retval = 0;
 297
 298         event_size = ((list->flags & HIDDEV_FLAG_UREF) != 0) ?
 299                 sizeof(struct hiddev_usage_ref) : sizeof(struct hiddev_event);
 300
 301         if (count < event_size)
 302                 return 0;
 303
 304         while (retval == 0) {
 305                 if (list->head == list->tail) {
 306                         add_wait_queue(&list->hiddev->wait, &wait);
 307                         set_current_state(TASK_INTERRUPTIBLE);
 308
 309                         while (list->head == list->tail) {
 310                                 if (file->f_flags & O_NONBLOCK) {
 311                                         retval = -EAGAIN;
 312                                         break;
 313                                 }
 314                                 if (signal_pending(current)) {
 315                                         retval = -ERESTARTSYS;
 316                                         break;
 317                                 }
 318                                 if (!list->hiddev->exist) {
 319                                         retval = -EIO;
 320                                         break;
 321                                 }
 322
 323                                 schedule();
 324                                 set_current_state(TASK_INTERRUPTIBLE);
 325                         }
 326
 327                         set_current_state(TASK_RUNNING);
 328                         remove_wait_queue(&list->hiddev->wait, &wait);
 329                 }
 330
 331                 if (retval)
 332                         return retval;
 333
 334
 335                 while (list->head != list->tail &&
 336                        retval + event_size <= count) {
 337                         if ((list->flags & HIDDEV_FLAG_UREF) == 0) {
 338                                 if (list->buffer[list->tail].field_index !=
 339                                     HID_FIELD_INDEX_NONE) {
 340                                         struct hiddev_event event;
 341                                         event.hid = list->buffer[list->tail].usage_code;
 342                                         event.value = list->buffer[list->tail].value;
 343                                         if (copy_to_user(buffer + retval, &event, sizeof(struct hiddev_event)))
 344                                                 return -EFAULT;
 345                                         retval += sizeof(struct hiddev_event);
 346                                 }
 347                         } else {
 348                                 if (list->buffer[list->tail].field_index != HID_FIELD_INDEX_NONE ||
 349                                     (list->flags & HIDDEV_FLAG_REPORT) != 0) {
 350                                         if (copy_to_user(buffer + retval, list->buffer + list->tail, sizeof(struct hiddev_usage_ref)))
 351                                                 return -EFAULT;
 352                                         retval += sizeof(struct hiddev_usage_ref);
 353                                 }
 354                         }
 355                         list->tail = (list->tail + 1) & (HIDDEV_BUFFER_SIZE - 1);
 356                 }
 357
 358         }
 359
 360         return retval;
 361 }
 362
 363 /*
 364  * "poll" file op
 365  * No kernel lock - fine
 366  */
 367 static unsigned int hiddev_poll(struct file *file, poll_table *wait)
 368 {
 369         struct hiddev_list *list = file->private_data;
 370
 371         poll_wait(file, &list->hiddev->wait, wait);
 372         if (list->head != list->tail)
 373                 return POLLIN | POLLRDNORM;
 374         if (!list->hiddev->exist)
 375                 return POLLERR | POLLHUP;
 376         return 0;
 377 }
 378
 379 /*
 380  * "ioctl" file op
 381  */
 382 static int hiddev_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
 383 {
 384         struct hiddev_list *list = file->private_data;
 385         struct hiddev *hiddev = list->hiddev;
 386         struct hid_device *hid = hiddev->hid;
 387         struct usb_device *dev = hid_to_usb_dev(hid);
 388         struct hiddev_collection_info cinfo;
 389         struct hiddev_report_info rinfo;
 390         struct hiddev_field_info finfo;
 391         struct hiddev_usage_ref_multi *uref_multi = NULL;
 392         struct hiddev_usage_ref *uref;
 393         struct hiddev_devinfo dinfo;
 394         struct hid_report *report;
 395         struct hid_field *field;
 396         struct usbhid_device *usbhid = hid->driver_data;
 397         void __user *user_arg = (void __user *)arg;
 398         int i;
 399
 400         if (!hiddev->exist)
 401                 return -EIO;
 402
 403         switch (cmd) {
 404
 405         case HIDIOCGVERSION:
 406                 return put_user(HID_VERSION, (int __user *)arg);
 407
 408         case HIDIOCAPPLICATION:
 409                 if (arg < 0 || arg >= hid->maxapplication)
 410                         return -EINVAL;
 411
 412                 for (i = 0; i < hid->maxcollection; i++)
 413                         if (hid->collection[i].type ==
 414                             HID_COLLECTION_APPLICATION && arg-- == 0)
 415                                 break;
 416
 417                 if (i == hid->maxcollection)
 418                         return -EINVAL;
 419
 420                 return hid->collection[i].usage;
 421
 422         case HIDIOCGDEVINFO:
 423                 dinfo.bustype = BUS_USB;
 424                 dinfo.busnum = dev->bus->busnum;
 425                 dinfo.devnum = dev->devnum;
 426                 dinfo.ifnum = usbhid->ifnum;
 427                 dinfo.vendor = le16_to_cpu(dev->descriptor.idVendor);
 428                 dinfo.product = le16_to_cpu(dev->descriptor.idProduct);
 429                 dinfo.version = le16_to_cpu(dev->descriptor.bcdDevice);
 430                 dinfo.num_applications = hid->maxapplication;
 431                 if (copy_to_user(user_arg, &dinfo, sizeof(dinfo)))
 432                         return -EFAULT;
 433
 434                 return 0;
 435
 436         case HIDIOCGFLAG:
 437                 if (put_user(list->flags, (int __user *)arg))
 438                         return -EFAULT;
 439
 440                 return 0;
 441
 442         case HIDIOCSFLAG:
 443                 {
 444                         int newflags;
 445                         if (get_user(newflags, (int __user *)arg))
 446                                 return -EFAULT;
 447
 448                         if ((newflags & ~HIDDEV_FLAGS) != 0 ||
 449                             ((newflags & HIDDEV_FLAG_REPORT) != 0 &&
 450                              (newflags & HIDDEV_FLAG_UREF) == 0))
 451                                 return -EINVAL;
 452
 453                         list->flags = newflags;
 454
 455                         return 0;
 456                 }
 457
 458         case HIDIOCGSTRING:
 459                 {
 460                         int idx, len;
 461                         char *buf;
 462
 463                         if (get_user(idx, (int __user *)arg))
 464                                 return -EFAULT;
 465
 466                         if ((buf = kmalloc(HID_STRING_SIZE, GFP_KERNEL)) == NULL)
 467                                 return -ENOMEM;
 468
 469                         if ((len = usb_string(dev, idx, buf, HID_STRING_SIZE-1)) < 0) {
 470                                 kfree(buf);
 471                                 return -EINVAL;
 472                         }
 473
 474                         if (copy_to_user(user_arg+sizeof(int), buf, len+1)) {
 475                                 kfree(buf);
 476                                 return -EFAULT;
 477                         }
 478
 479                         kfree(buf);
 480
 481                         return len;
 482                 }
 483
 484         case HIDIOCINITREPORT:
 485                 usbhid_init_reports(hid);
 486
 487                 return 0;
 488
 489         case HIDIOCGREPORT:
 490                 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
 491                         return -EFAULT;
 492
 493                 if (rinfo.report_type == HID_REPORT_TYPE_OUTPUT)
 494                         return -EINVAL;
 495
 496                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 497                         return -EINVAL;
 498
 499                 usbhid_submit_report(hid, report, USB_DIR_IN);
 500                 usbhid_wait_io(hid);
 501
 502                 return 0;
 503
 504         case HIDIOCSREPORT:
 505                 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
 506                         return -EFAULT;
 507
 508                 if (rinfo.report_type == HID_REPORT_TYPE_INPUT)
 509                         return -EINVAL;
 510
 511                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 512                         return -EINVAL;
 513
 514                 usbhid_submit_report(hid, report, USB_DIR_OUT);
 515                 usbhid_wait_io(hid);
 516
 517                 return 0;
 518
 519         case HIDIOCGREPORTINFO:
 520                 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
 521                         return -EFAULT;
 522
 523                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 524                         return -EINVAL;
 525
 526                 rinfo.num_fields = report->maxfield;
 527
 528                 if (copy_to_user(user_arg, &rinfo, sizeof(rinfo)))
 529                         return -EFAULT;
 530
 531                 return 0;
 532
 533         case HIDIOCGFIELDINFO:
 534                 if (copy_from_user(&finfo, user_arg, sizeof(finfo)))
 535                         return -EFAULT;
 536                 rinfo.report_type = finfo.report_type;
 537                 rinfo.report_id = finfo.report_id;
 538                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 539                         return -EINVAL;
 540
 541                 if (finfo.field_index >= report->maxfield)
 542                         return -EINVAL;
 543
 544                 field = report->field[finfo.field_index];
 545                 memset(&finfo, 0, sizeof(finfo));
 546                 finfo.report_type = rinfo.report_type;
 547                 finfo.report_id = rinfo.report_id;
 548                 finfo.field_index = field->report_count - 1;
 549                 finfo.maxusage = field->maxusage;
 550                 finfo.flags = field->flags;
 551                 finfo.physical = field->physical;
 552                 finfo.logical = field->logical;
 553                 finfo.application = field->application;
 554                 finfo.logical_minimum = field->logical_minimum;
 555                 finfo.logical_maximum = field->logical_maximum;
 556                 finfo.physical_minimum = field->physical_minimum;
 557                 finfo.physical_maximum = field->physical_maximum;
 558                 finfo.unit_exponent = field->unit_exponent;
 559                 finfo.unit = field->unit;
 560
 561                 if (copy_to_user(user_arg, &finfo, sizeof(finfo)))
 562                         return -EFAULT;
 563
 564                 return 0;
 565
 566         case HIDIOCGUCODE:
 567                 uref_multi = kmalloc(sizeof(struct hiddev_usage_ref_multi), GFP_KERNEL);
 568                 if (!uref_multi)
 569                         return -ENOMEM;
 570                 uref = &uref_multi->uref;
 571                 if (copy_from_user(uref, user_arg, sizeof(*uref)))
 572                         goto fault;
 573
 574                 rinfo.report_type = uref->report_type;
 575                 rinfo.report_id = uref->report_id;
 576                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 577                         goto inval;
 578
 579                 if (uref->field_index >= report->maxfield)
 580                         goto inval;
 581
 582                 field = report->field[uref->field_index];
 583                 if (uref->usage_index >= field->maxusage)
 584                         goto inval;
 585
 586                 uref->usage_code = field->usage[uref->usage_index].hid;
 587
 588                 if (copy_to_user(user_arg, uref, sizeof(*uref)))
 589                         goto fault;
 590
 591                 kfree(uref_multi);
 592                 return 0;
 593
 594         case HIDIOCGUSAGE:
 595         case HIDIOCSUSAGE:
 596         case HIDIOCGUSAGES:
 597         case HIDIOCSUSAGES:
 598         case HIDIOCGCOLLECTIONINDEX:
 599                 uref_multi = kmalloc(sizeof(struct hiddev_usage_ref_multi), GFP_KERNEL);
 600                 if (!uref_multi)
 601                         return -ENOMEM;
 602                 uref = &uref_multi->uref;
 603                 if (cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) {
 604                         if (copy_from_user(uref_multi, user_arg,
 605                                            sizeof(*uref_multi)))
 606                                 goto fault;
 607                 } else {
 608                         if (copy_from_user(uref, user_arg, sizeof(*uref)))
 609                                 goto fault;
 610                 }
 611
 612                 if (cmd != HIDIOCGUSAGE &&
 613                     cmd != HIDIOCGUSAGES &&
 614                     uref->report_type == HID_REPORT_TYPE_INPUT)
 615                         goto inval;
 616
 617                 if (uref->report_id == HID_REPORT_ID_UNKNOWN) {
 618                         field = hiddev_lookup_usage(hid, uref);
 619                         if (field == NULL)
 620                                 goto inval;
 621                 } else {
 622                         rinfo.report_type = uref->report_type;
 623                         rinfo.report_id = uref->report_id;
 624                         if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 625                                 goto inval;
 626
 627                         if (uref->field_index >= report->maxfield)
 628                                 goto inval;
 629
 630                         field = report->field[uref->field_index];
 631
 632                         if (cmd == HIDIOCGCOLLECTIONINDEX) {
 633                                 if (uref->usage_index >= field->maxusage)
 634                                         goto inval;
 635                         } else if (uref->usage_index >= field->report_count)
 636                                 goto inval;
 637
 638                         else if ((cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) &&
 639                                  (uref_multi->num_values > HID_MAX_MULTI_USAGES ||
 640                                   uref->usage_index + uref_multi->num_values > field->report_count))
 641                                 goto inval;
 642                         }
 643
 644                 switch (cmd) {
 645                         case HIDIOCGUSAGE:
 646                                 uref->value = field->value[uref->usage_index];
 647                                 if (copy_to_user(user_arg, uref, sizeof(*uref)))
 648                                         goto fault;
 649                                 goto goodreturn;
 650
 651                         case HIDIOCSUSAGE:
 652                                 field->value[uref->usage_index] = uref->value;
 653                                 goto goodreturn;
 654
 655                         case HIDIOCGCOLLECTIONINDEX:
 656                                 kfree(uref_multi);
 657                                 return field->usage[uref->usage_index].collection_index;
 658                         case HIDIOCGUSAGES:
 659                                 for (i = 0; i < uref_multi->num_values; i++)
 660                                         uref_multi->values[i] =
 661                                             field->value[uref->usage_index + i];
 662                                 if (copy_to_user(user_arg, uref_multi,
 663                                                  sizeof(*uref_multi)))
 664                                         goto fault;
 665                                 goto goodreturn;
 666                         case HIDIOCSUSAGES:
 667                                 for (i = 0; i < uref_multi->num_values; i++)
 668                                         field->value[uref->usage_index + i] =
 669                                             uref_multi->values[i];
 670                                 goto goodreturn;
 671                 }
 672
 673 goodreturn:
 674                 kfree(uref_multi);
 675                 return 0;
 676 fault:
 677                 kfree(uref_multi);
 678                 return -EFAULT;
 679 inval:
 680                 kfree(uref_multi);
 681                 return -EINVAL;
 682
 683         case HIDIOCGCOLLECTIONINFO:
 684                 if (copy_from_user(&cinfo, user_arg, sizeof(cinfo)))
 685                         return -EFAULT;
 686
 687                 if (cinfo.index >= hid->maxcollection)
 688                         return -EINVAL;
 689
 690                 cinfo.type = hid->collection[cinfo.index].type;
 691                 cinfo.usage = hid->collection[cinfo.index].usage;
 692                 cinfo.level = hid->collection[cinfo.index].level;
 693
 694                 if (copy_to_user(user_arg, &cinfo, sizeof(cinfo)))
 695                         return -EFAULT;
 696                 return 0;
 697
 698         default:
 699
 700                 if (_IOC_TYPE(cmd) != 'H' || _IOC_DIR(cmd) != _IOC_READ)
 701                         return -EINVAL;
 702
 703                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGNAME(0))) {
 704                         int len;
 705                         if (!hid->name)
 706                                 return 0;
 707                         len = strlen(hid->name) + 1;
 708                         if (len > _IOC_SIZE(cmd))
 709                                  len = _IOC_SIZE(cmd);
 710                         return copy_to_user(user_arg, hid->name, len) ?
 711                                 -EFAULT : len;
 712                 }
 713
 714                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGPHYS(0))) {
 715                         int len;
 716                         if (!hid->phys)
 717                                 return 0;
 718                         len = strlen(hid->phys) + 1;
 719                         if (len > _IOC_SIZE(cmd))
 720                                 len = _IOC_SIZE(cmd);
 721                         return copy_to_user(user_arg, hid->phys, len) ?
 722                                 -EFAULT : len;
 723                 }
 724         }
 725         return -EINVAL;
 726 }
 727
 728 static const struct file_operations hiddev_fops = {
 729         .owner =        THIS_MODULE,
 730         .read =         hiddev_read,
 731         .write =        hiddev_write,
 732         .poll =         hiddev_poll,
 733         .open =         hiddev_open,
 734         .release =      hiddev_release,
 735         .ioctl =        hiddev_ioctl,
 736         .fasync =       hiddev_fasync,
 737 };
 738
 739 static struct usb_class_driver hiddev_class = {
 740         .name =         "hiddev%d",
 741         .fops =         &hiddev_fops,
 742         .minor_base =   HIDDEV_MINOR_BASE,
 743 };
 744
 745 /*
 746  * This is where hid.c calls us to connect a hid device to the hiddev driver
 747  */
 748 int hiddev_connect(struct hid_device *hid)
 749 {
 750         struct hiddev *hiddev;
 751         struct usbhid_device *usbhid = hid->driver_data;
 752         int i;
 753         int retval;
 754
 755         for (i = 0; i < hid->maxcollection; i++)
 756                 if (hid->collection[i].type ==
 757                     HID_COLLECTION_APPLICATION &&
 758                     !IS_INPUT_APPLICATION(hid->collection[i].usage))
 759                         break;
 760
 761         if (i == hid->maxcollection && (hid->quirks & HID_QUIRK_HIDDEV) == 0)
 762                 return -1;
 763
 764         if (!(hiddev = kzalloc(sizeof(struct hiddev), GFP_KERNEL)))
 765                 return -1;
 766
 767         retval = usb_register_dev(usbhid->intf, &hiddev_class);
 768         if (retval) {
 769                 err("Not able to get a minor for this device.");
 770                 kfree(hiddev);
 771                 return -1;
 772         }
 773
 774         init_waitqueue_head(&hiddev->wait);
 775         INIT_LIST_HEAD(&hiddev->list);
 776         hiddev->hid = hid;
 777         hiddev->exist = 1;
 778
 779         hid->minor = usbhid->intf->minor;
 780         hid->hiddev = hiddev;
 781
 782         hiddev_table[usbhid->intf->minor - HIDDEV_MINOR_BASE] = hiddev;
 783
 784         return 0;
 785 }
 786
 787 /*
 788  * This is where hid.c calls us to disconnect a hiddev device from the
 789  * corresponding hid device (usually because the usb device has disconnected)
 790  */
 791 static struct usb_class_driver hiddev_class;
 792 void hiddev_disconnect(struct hid_device *hid)
 793 {
 794         struct hiddev *hiddev = hid->hiddev;
 795         struct usbhid_device *usbhid = hid->driver_data;
 796
 797         hiddev->exist = 0;
 798
 799         hiddev_table[hiddev->hid->minor - HIDDEV_MINOR_BASE] = NULL;
 800         usb_deregister_dev(usbhid->intf, &hiddev_class);
 801
 802         if (hiddev->open) {
 803                 usbhid_close(hiddev->hid);
 804                 wake_up_interruptible(&hiddev->wait);
 805         } else {
 806                 kfree(hiddev);
 807         }
 808 }
 809
 810 /* Currently this driver is a USB driver.  It's not a conventional one in
 811  * the sense that it doesn't probe at the USB level.  Instead it waits to
 812  * be connected by HID through the hiddev_connect / hiddev_disconnect
 813  * routines.  The reason to register as a USB device is to gain part of the
 814  * minor number space from the USB major.
 815  *
 816  * In theory, should the HID code be generalized to more than one physical
 817  * medium (say, IEEE 1384), this driver will probably need to register its
 818  * own major number, and in doing so, no longer need to register with USB.
 819  * At that point the probe routine and hiddev_driver struct below will no
 820  * longer be useful.
 821  */
 822
 823
 824 /* We never attach in this manner, and rely on HID to connect us.  This
 825  * is why there is no disconnect routine defined in the usb_driver either.
 826  */
 827 static int hiddev_usbd_probe(struct usb_interface *intf,
 828                              const struct usb_device_id *hiddev_info)
 829 {
 830         return -ENODEV;
 831 }
 832
 833
 834 static /* const */ struct usb_driver hiddev_driver = {
 835         .name =         "hiddev",
 836         .probe =        hiddev_usbd_probe,
 837 };
 838
 839 int __init hiddev_init(void)
 840 {
 841         return usb_register(&hiddev_driver);
 842 }
 843
 844 void hiddev_exit(void)
 845 {
 846         usb_deregister(&hiddev_driver);
 847 }