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         spinlock_t list_lock;
  55 };
  56
  57 struct hiddev_list {
  58         struct hiddev_usage_ref buffer[HIDDEV_BUFFER_SIZE];
  59         int head;
  60         int tail;
  61         unsigned flags;
  62         struct fasync_struct *fasync;
  63         struct hiddev *hiddev;
  64         struct list_head node;
  65 };
  66
  67 static struct hiddev *hiddev_table[HIDDEV_MINORS];
  68
  69 /*
  70  * Find a report, given the report's type and ID.  The ID can be specified
  71  * indirectly by REPORT_ID_FIRST (which returns the first report of the given
  72  * type) or by (REPORT_ID_NEXT | old_id), which returns the next report of the
  73  * given type which follows old_id.
  74  */
  75 static struct hid_report *
  76 hiddev_lookup_report(struct hid_device *hid, struct hiddev_report_info *rinfo)
  77 {
  78         unsigned int flags = rinfo->report_id & ~HID_REPORT_ID_MASK;
  79         unsigned int rid = rinfo->report_id & HID_REPORT_ID_MASK;
  80         struct hid_report_enum *report_enum;
  81         struct hid_report *report;
  82         struct list_head *list;
  83
  84         if (rinfo->report_type < HID_REPORT_TYPE_MIN ||
  85             rinfo->report_type > HID_REPORT_TYPE_MAX)
  86                 return NULL;
  87
  88         report_enum = hid->report_enum +
  89                 (rinfo->report_type - HID_REPORT_TYPE_MIN);
  90
  91         switch (flags) {
  92         case 0: /* Nothing to do -- report_id is already set correctly */
  93                 break;
  94
  95         case HID_REPORT_ID_FIRST:
  96                 if (list_empty(&report_enum->report_list))
  97                         return NULL;
  98
  99                 list = report_enum->report_list.next;
 100                 report = list_entry(list, struct hid_report, list);
 101                 rinfo->report_id = report->id;
 102                 break;
 103
 104         case HID_REPORT_ID_NEXT:
 105                 report = report_enum->report_id_hash[rid];
 106                 if (!report)
 107                         return NULL;
 108
 109                 list = report->list.next;
 110                 if (list == &report_enum->report_list)
 111                         return NULL;
 112
 113                 report = list_entry(list, struct hid_report, list);
 114                 rinfo->report_id = report->id;
 115                 break;
 116
 117         default:
 118                 return NULL;
 119         }
 120
 121         return report_enum->report_id_hash[rinfo->report_id];
 122 }
 123
 124 /*
 125  * Perform an exhaustive search of the report table for a usage, given its
 126  * type and usage id.
 127  */
 128 static struct hid_field *
 129 hiddev_lookup_usage(struct hid_device *hid, struct hiddev_usage_ref *uref)
 130 {
 131         int i, j;
 132         struct hid_report *report;
 133         struct hid_report_enum *report_enum;
 134         struct hid_field *field;
 135
 136         if (uref->report_type < HID_REPORT_TYPE_MIN ||
 137             uref->report_type > HID_REPORT_TYPE_MAX)
 138                 return NULL;
 139
 140         report_enum = hid->report_enum +
 141                 (uref->report_type - HID_REPORT_TYPE_MIN);
 142
 143         list_for_each_entry(report, &report_enum->report_list, list) {
 144                 for (i = 0; i < report->maxfield; i++) {
 145                         field = report->field[i];
 146                         for (j = 0; j < field->maxusage; j++) {
 147                                 if (field->usage[j].hid == uref->usage_code) {
 148                                         uref->report_id = report->id;
 149                                         uref->field_index = i;
 150                                         uref->usage_index = j;
 151                                         return field;
 152                                 }
 153                         }
 154                 }
 155         }
 156
 157         return NULL;
 158 }
 159
 160 static void hiddev_send_event(struct hid_device *hid,
 161                               struct hiddev_usage_ref *uref)
 162 {
 163         struct hiddev *hiddev = hid->hiddev;
 164         struct hiddev_list *list;
 165         unsigned long flags;
 166
 167         spin_lock_irqsave(&hiddev->list_lock, flags);
 168         list_for_each_entry(list, &hiddev->list, node) {
 169                 if (uref->field_index != HID_FIELD_INDEX_NONE ||
 170                     (list->flags & HIDDEV_FLAG_REPORT) != 0) {
 171                         list->buffer[list->head] = *uref;
 172                         list->head = (list->head + 1) &
 173                                 (HIDDEV_BUFFER_SIZE - 1);
 174                         kill_fasync(&list->fasync, SIGIO, POLL_IN);
 175                 }
 176         }
 177         spin_unlock_irqrestore(&hiddev->list_lock, flags);
 178
 179         wake_up_interruptible(&hiddev->wait);
 180 }
 181
 182 /*
 183  * This is where hid.c calls into hiddev to pass an event that occurred over
 184  * the interrupt pipe
 185  */
 186 void hiddev_hid_event(struct hid_device *hid, struct hid_field *field,
 187                       struct hid_usage *usage, __s32 value)
 188 {
 189         unsigned type = field->report_type;
 190         struct hiddev_usage_ref uref;
 191
 192         uref.report_type =
 193           (type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
 194           ((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
 195            ((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE : 0));
 196         uref.report_id = field->report->id;
 197         uref.field_index = field->index;
 198         uref.usage_index = (usage - field->usage);
 199         uref.usage_code = usage->hid;
 200         uref.value = value;
 201
 202         hiddev_send_event(hid, &uref);
 203 }
 204 EXPORT_SYMBOL_GPL(hiddev_hid_event);
 205
 206 void hiddev_report_event(struct hid_device *hid, struct hid_report *report)
 207 {
 208         unsigned type = report->type;
 209         struct hiddev_usage_ref uref;
 210
 211         memset(&uref, 0, sizeof(uref));
 212         uref.report_type =
 213           (type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
 214           ((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
 215            ((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE : 0));
 216         uref.report_id = report->id;
 217         uref.field_index = HID_FIELD_INDEX_NONE;
 218
 219         hiddev_send_event(hid, &uref);
 220 }
 221
 222 /*
 223  * fasync file op
 224  */
 225 static int hiddev_fasync(int fd, struct file *file, int on)
 226 {
 227         int retval;
 228         struct hiddev_list *list = file->private_data;
 229
 230         retval = fasync_helper(fd, file, on, &list->fasync);
 231
 232         return retval < 0 ? retval : 0;
 233 }
 234
 235
 236 /*
 237  * release file op
 238  */
 239 static int hiddev_release(struct inode * inode, struct file * file)
 240 {
 241         struct hiddev_list *list = file->private_data;
 242         unsigned long flags;
 243
 244         hiddev_fasync(-1, file, 0);
 245
 246         spin_lock_irqsave(&list->hiddev->list_lock, flags);
 247         list_del(&list->node);
 248         spin_unlock_irqrestore(&list->hiddev->list_lock, flags);
 249
 250         if (!--list->hiddev->open) {
 251                 if (list->hiddev->exist)
 252                         usbhid_close(list->hiddev->hid);
 253                 else
 254                         kfree(list->hiddev);
 255         }
 256
 257         kfree(list);
 258
 259         return 0;
 260 }
 261
 262 /*
 263  * open file op
 264  */
 265 static int hiddev_open(struct inode *inode, struct file *file)
 266 {
 267         struct hiddev_list *list;
 268         unsigned long flags;
 269
 270         int i = iminor(inode) - HIDDEV_MINOR_BASE;
 271
 272         if (i >= HIDDEV_MINORS || !hiddev_table[i])
 273                 return -ENODEV;
 274
 275         if (!(list = kzalloc(sizeof(struct hiddev_list), GFP_KERNEL)))
 276                 return -ENOMEM;
 277
 278         list->hiddev = hiddev_table[i];
 279
 280         spin_lock_irqsave(&list->hiddev->list_lock, flags);
 281         list_add_tail(&list->node, &hiddev_table[i]->list);
 282         spin_unlock_irqrestore(&list->hiddev->list_lock, flags);
 283
 284         file->private_data = list;
 285
 286         if (!list->hiddev->open++)
 287                 if (list->hiddev->exist)
 288                         usbhid_open(hiddev_table[i]->hid);
 289
 290         return 0;
 291 }
 292
 293 /*
 294  * "write" file op
 295  */
 296 static ssize_t hiddev_write(struct file * file, const char __user * buffer, size_t count, loff_t *ppos)
 297 {
 298         return -EINVAL;
 299 }
 300
 301 /*
 302  * "read" file op
 303  */
 304 static ssize_t hiddev_read(struct file * file, char __user * buffer, size_t count, loff_t *ppos)
 305 {
 306         DECLARE_WAITQUEUE(wait, current);
 307         struct hiddev_list *list = file->private_data;
 308         int event_size;
 309         int retval = 0;
 310
 311         event_size = ((list->flags & HIDDEV_FLAG_UREF) != 0) ?
 312                 sizeof(struct hiddev_usage_ref) : sizeof(struct hiddev_event);
 313
 314         if (count < event_size)
 315                 return 0;
 316
 317         while (retval == 0) {
 318                 if (list->head == list->tail) {
 319                         add_wait_queue(&list->hiddev->wait, &wait);
 320                         set_current_state(TASK_INTERRUPTIBLE);
 321
 322                         while (list->head == list->tail) {
 323                                 if (file->f_flags & O_NONBLOCK) {
 324                                         retval = -EAGAIN;
 325                                         break;
 326                                 }
 327                                 if (signal_pending(current)) {
 328                                         retval = -ERESTARTSYS;
 329                                         break;
 330                                 }
 331                                 if (!list->hiddev->exist) {
 332                                         retval = -EIO;
 333                                         break;
 334                                 }
 335
 336                                 schedule();
 337                                 set_current_state(TASK_INTERRUPTIBLE);
 338                         }
 339
 340                         set_current_state(TASK_RUNNING);
 341                         remove_wait_queue(&list->hiddev->wait, &wait);
 342                 }
 343
 344                 if (retval)
 345                         return retval;
 346
 347
 348                 while (list->head != list->tail &&
 349                        retval + event_size <= count) {
 350                         if ((list->flags & HIDDEV_FLAG_UREF) == 0) {
 351                                 if (list->buffer[list->tail].field_index !=
 352                                     HID_FIELD_INDEX_NONE) {
 353                                         struct hiddev_event event;
 354                                         event.hid = list->buffer[list->tail].usage_code;
 355                                         event.value = list->buffer[list->tail].value;
 356                                         if (copy_to_user(buffer + retval, &event, sizeof(struct hiddev_event)))
 357                                                 return -EFAULT;
 358                                         retval += sizeof(struct hiddev_event);
 359                                 }
 360                         } else {
 361                                 if (list->buffer[list->tail].field_index != HID_FIELD_INDEX_NONE ||
 362                                     (list->flags & HIDDEV_FLAG_REPORT) != 0) {
 363                                         if (copy_to_user(buffer + retval, list->buffer + list->tail, sizeof(struct hiddev_usage_ref)))
 364                                                 return -EFAULT;
 365                                         retval += sizeof(struct hiddev_usage_ref);
 366                                 }
 367                         }
 368                         list->tail = (list->tail + 1) & (HIDDEV_BUFFER_SIZE - 1);
 369                 }
 370
 371         }
 372
 373         return retval;
 374 }
 375
 376 /*
 377  * "poll" file op
 378  * No kernel lock - fine
 379  */
 380 static unsigned int hiddev_poll(struct file *file, poll_table *wait)
 381 {
 382         struct hiddev_list *list = file->private_data;
 383
 384         poll_wait(file, &list->hiddev->wait, wait);
 385         if (list->head != list->tail)
 386                 return POLLIN | POLLRDNORM;
 387         if (!list->hiddev->exist)
 388                 return POLLERR | POLLHUP;
 389         return 0;
 390 }
 391
 392 /*
 393  * "ioctl" file op
 394  */
 395 static int hiddev_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
 396 {
 397         struct hiddev_list *list = file->private_data;
 398         struct hiddev *hiddev = list->hiddev;
 399         struct hid_device *hid = hiddev->hid;
 400         struct usb_device *dev = hid_to_usb_dev(hid);
 401         struct hiddev_collection_info cinfo;
 402         struct hiddev_report_info rinfo;
 403         struct hiddev_field_info finfo;
 404         struct hiddev_usage_ref_multi *uref_multi = NULL;
 405         struct hiddev_usage_ref *uref;
 406         struct hiddev_devinfo dinfo;
 407         struct hid_report *report;
 408         struct hid_field *field;
 409         struct usbhid_device *usbhid = hid->driver_data;
 410         void __user *user_arg = (void __user *)arg;
 411         int i;
 412
 413         if (!hiddev->exist)
 414                 return -EIO;
 415
 416         switch (cmd) {
 417
 418         case HIDIOCGVERSION:
 419                 return put_user(HID_VERSION, (int __user *)arg);
 420
 421         case HIDIOCAPPLICATION:
 422                 if (arg < 0 || arg >= hid->maxapplication)
 423                         return -EINVAL;
 424
 425                 for (i = 0; i < hid->maxcollection; i++)
 426                         if (hid->collection[i].type ==
 427                             HID_COLLECTION_APPLICATION && arg-- == 0)
 428                                 break;
 429
 430                 if (i == hid->maxcollection)
 431                         return -EINVAL;
 432
 433                 return hid->collection[i].usage;
 434
 435         case HIDIOCGDEVINFO:
 436                 dinfo.bustype = BUS_USB;
 437                 dinfo.busnum = dev->bus->busnum;
 438                 dinfo.devnum = dev->devnum;
 439                 dinfo.ifnum = usbhid->ifnum;
 440                 dinfo.vendor = le16_to_cpu(dev->descriptor.idVendor);
 441                 dinfo.product = le16_to_cpu(dev->descriptor.idProduct);
 442                 dinfo.version = le16_to_cpu(dev->descriptor.bcdDevice);
 443                 dinfo.num_applications = hid->maxapplication;
 444                 if (copy_to_user(user_arg, &dinfo, sizeof(dinfo)))
 445                         return -EFAULT;
 446
 447                 return 0;
 448
 449         case HIDIOCGFLAG:
 450                 if (put_user(list->flags, (int __user *)arg))
 451                         return -EFAULT;
 452
 453                 return 0;
 454
 455         case HIDIOCSFLAG:
 456                 {
 457                         int newflags;
 458                         if (get_user(newflags, (int __user *)arg))
 459                                 return -EFAULT;
 460
 461                         if ((newflags & ~HIDDEV_FLAGS) != 0 ||
 462                             ((newflags & HIDDEV_FLAG_REPORT) != 0 &&
 463                              (newflags & HIDDEV_FLAG_UREF) == 0))
 464                                 return -EINVAL;
 465
 466                         list->flags = newflags;
 467
 468                         return 0;
 469                 }
 470
 471         case HIDIOCGSTRING:
 472                 {
 473                         int idx, len;
 474                         char *buf;
 475
 476                         if (get_user(idx, (int __user *)arg))
 477                                 return -EFAULT;
 478
 479                         if ((buf = kmalloc(HID_STRING_SIZE, GFP_KERNEL)) == NULL)
 480                                 return -ENOMEM;
 481
 482                         if ((len = usb_string(dev, idx, buf, HID_STRING_SIZE-1)) < 0) {
 483                                 kfree(buf);
 484                                 return -EINVAL;
 485                         }
 486
 487                         if (copy_to_user(user_arg+sizeof(int), buf, len+1)) {
 488                                 kfree(buf);
 489                                 return -EFAULT;
 490                         }
 491
 492                         kfree(buf);
 493
 494                         return len;
 495                 }
 496
 497         case HIDIOCINITREPORT:
 498                 usbhid_init_reports(hid);
 499
 500                 return 0;
 501
 502         case HIDIOCGREPORT:
 503                 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
 504                         return -EFAULT;
 505
 506                 if (rinfo.report_type == HID_REPORT_TYPE_OUTPUT)
 507                         return -EINVAL;
 508
 509                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 510                         return -EINVAL;
 511
 512                 usbhid_submit_report(hid, report, USB_DIR_IN);
 513                 usbhid_wait_io(hid);
 514
 515                 return 0;
 516
 517         case HIDIOCSREPORT:
 518                 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
 519                         return -EFAULT;
 520
 521                 if (rinfo.report_type == HID_REPORT_TYPE_INPUT)
 522                         return -EINVAL;
 523
 524                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 525                         return -EINVAL;
 526
 527                 usbhid_submit_report(hid, report, USB_DIR_OUT);
 528                 usbhid_wait_io(hid);
 529
 530                 return 0;
 531
 532         case HIDIOCGREPORTINFO:
 533                 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
 534                         return -EFAULT;
 535
 536                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 537                         return -EINVAL;
 538
 539                 rinfo.num_fields = report->maxfield;
 540
 541                 if (copy_to_user(user_arg, &rinfo, sizeof(rinfo)))
 542                         return -EFAULT;
 543
 544                 return 0;
 545
 546         case HIDIOCGFIELDINFO:
 547                 if (copy_from_user(&finfo, user_arg, sizeof(finfo)))
 548                         return -EFAULT;
 549                 rinfo.report_type = finfo.report_type;
 550                 rinfo.report_id = finfo.report_id;
 551                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 552                         return -EINVAL;
 553
 554                 if (finfo.field_index >= report->maxfield)
 555                         return -EINVAL;
 556
 557                 field = report->field[finfo.field_index];
 558                 memset(&finfo, 0, sizeof(finfo));
 559                 finfo.report_type = rinfo.report_type;
 560                 finfo.report_id = rinfo.report_id;
 561                 finfo.field_index = field->report_count - 1;
 562                 finfo.maxusage = field->maxusage;
 563                 finfo.flags = field->flags;
 564                 finfo.physical = field->physical;
 565                 finfo.logical = field->logical;
 566                 finfo.application = field->application;
 567                 finfo.logical_minimum = field->logical_minimum;
 568                 finfo.logical_maximum = field->logical_maximum;
 569                 finfo.physical_minimum = field->physical_minimum;
 570                 finfo.physical_maximum = field->physical_maximum;
 571                 finfo.unit_exponent = field->unit_exponent;
 572                 finfo.unit = field->unit;
 573
 574                 if (copy_to_user(user_arg, &finfo, sizeof(finfo)))
 575                         return -EFAULT;
 576
 577                 return 0;
 578
 579         case HIDIOCGUCODE:
 580                 uref_multi = kmalloc(sizeof(struct hiddev_usage_ref_multi), GFP_KERNEL);
 581                 if (!uref_multi)
 582                         return -ENOMEM;
 583                 uref = &uref_multi->uref;
 584                 if (copy_from_user(uref, user_arg, sizeof(*uref)))
 585                         goto fault;
 586
 587                 rinfo.report_type = uref->report_type;
 588                 rinfo.report_id = uref->report_id;
 589                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 590                         goto inval;
 591
 592                 if (uref->field_index >= report->maxfield)
 593                         goto inval;
 594
 595                 field = report->field[uref->field_index];
 596                 if (uref->usage_index >= field->maxusage)
 597                         goto inval;
 598
 599                 uref->usage_code = field->usage[uref->usage_index].hid;
 600
 601                 if (copy_to_user(user_arg, uref, sizeof(*uref)))
 602                         goto fault;
 603
 604                 kfree(uref_multi);
 605                 return 0;
 606
 607         case HIDIOCGUSAGE:
 608         case HIDIOCSUSAGE:
 609         case HIDIOCGUSAGES:
 610         case HIDIOCSUSAGES:
 611         case HIDIOCGCOLLECTIONINDEX:
 612                 uref_multi = kmalloc(sizeof(struct hiddev_usage_ref_multi), GFP_KERNEL);
 613                 if (!uref_multi)
 614                         return -ENOMEM;
 615                 uref = &uref_multi->uref;
 616                 if (cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) {
 617                         if (copy_from_user(uref_multi, user_arg,
 618                                            sizeof(*uref_multi)))
 619                                 goto fault;
 620                 } else {
 621                         if (copy_from_user(uref, user_arg, sizeof(*uref)))
 622                                 goto fault;
 623                 }
 624
 625                 if (cmd != HIDIOCGUSAGE &&
 626                     cmd != HIDIOCGUSAGES &&
 627                     uref->report_type == HID_REPORT_TYPE_INPUT)
 628                         goto inval;
 629
 630                 if (uref->report_id == HID_REPORT_ID_UNKNOWN) {
 631                         field = hiddev_lookup_usage(hid, uref);
 632                         if (field == NULL)
 633                                 goto inval;
 634                 } else {
 635                         rinfo.report_type = uref->report_type;
 636                         rinfo.report_id = uref->report_id;
 637                         if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 638                                 goto inval;
 639
 640                         if (uref->field_index >= report->maxfield)
 641                                 goto inval;
 642
 643                         field = report->field[uref->field_index];
 644
 645                         if (cmd == HIDIOCGCOLLECTIONINDEX) {
 646                                 if (uref->usage_index >= field->maxusage)
 647                                         goto inval;
 648                         } else if (uref->usage_index >= field->report_count)
 649                                 goto inval;
 650
 651                         else if ((cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) &&
 652                                  (uref_multi->num_values > HID_MAX_MULTI_USAGES ||
 653                                   uref->usage_index + uref_multi->num_values > field->report_count))
 654                                 goto inval;
 655                         }
 656
 657                 switch (cmd) {
 658                         case HIDIOCGUSAGE:
 659                                 uref->value = field->value[uref->usage_index];
 660                                 if (copy_to_user(user_arg, uref, sizeof(*uref)))
 661                                         goto fault;
 662                                 goto goodreturn;
 663
 664                         case HIDIOCSUSAGE:
 665                                 field->value[uref->usage_index] = uref->value;
 666                                 goto goodreturn;
 667
 668                         case HIDIOCGCOLLECTIONINDEX:
 669                                 kfree(uref_multi);
 670                                 return field->usage[uref->usage_index].collection_index;
 671                         case HIDIOCGUSAGES:
 672                                 for (i = 0; i < uref_multi->num_values; i++)
 673                                         uref_multi->values[i] =
 674                                             field->value[uref->usage_index + i];
 675                                 if (copy_to_user(user_arg, uref_multi,
 676                                                  sizeof(*uref_multi)))
 677                                         goto fault;
 678                                 goto goodreturn;
 679                         case HIDIOCSUSAGES:
 680                                 for (i = 0; i < uref_multi->num_values; i++)
 681                                         field->value[uref->usage_index + i] =
 682                                             uref_multi->values[i];
 683                                 goto goodreturn;
 684                 }
 685
 686 goodreturn:
 687                 kfree(uref_multi);
 688                 return 0;
 689 fault:
 690                 kfree(uref_multi);
 691                 return -EFAULT;
 692 inval:
 693                 kfree(uref_multi);
 694                 return -EINVAL;
 695
 696         case HIDIOCGCOLLECTIONINFO:
 697                 if (copy_from_user(&cinfo, user_arg, sizeof(cinfo)))
 698                         return -EFAULT;
 699
 700                 if (cinfo.index >= hid->maxcollection)
 701                         return -EINVAL;
 702
 703                 cinfo.type = hid->collection[cinfo.index].type;
 704                 cinfo.usage = hid->collection[cinfo.index].usage;
 705                 cinfo.level = hid->collection[cinfo.index].level;
 706
 707                 if (copy_to_user(user_arg, &cinfo, sizeof(cinfo)))
 708                         return -EFAULT;
 709                 return 0;
 710
 711         default:
 712
 713                 if (_IOC_TYPE(cmd) != 'H' || _IOC_DIR(cmd) != _IOC_READ)
 714                         return -EINVAL;
 715
 716                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGNAME(0))) {
 717                         int len;
 718                         if (!hid->name)
 719                                 return 0;
 720                         len = strlen(hid->name) + 1;
 721                         if (len > _IOC_SIZE(cmd))
 722                                  len = _IOC_SIZE(cmd);
 723                         return copy_to_user(user_arg, hid->name, len) ?
 724                                 -EFAULT : len;
 725                 }
 726
 727                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGPHYS(0))) {
 728                         int len;
 729                         if (!hid->phys)
 730                                 return 0;
 731                         len = strlen(hid->phys) + 1;
 732                         if (len > _IOC_SIZE(cmd))
 733                                 len = _IOC_SIZE(cmd);
 734                         return copy_to_user(user_arg, hid->phys, len) ?
 735                                 -EFAULT : len;
 736                 }
 737         }
 738         return -EINVAL;
 739 }
 740
 741 static const struct file_operations hiddev_fops = {
 742         .owner =        THIS_MODULE,
 743         .read =         hiddev_read,
 744         .write =        hiddev_write,
 745         .poll =         hiddev_poll,
 746         .open =         hiddev_open,
 747         .release =      hiddev_release,
 748         .ioctl =        hiddev_ioctl,
 749         .fasync =       hiddev_fasync,
 750 };
 751
 752 static struct usb_class_driver hiddev_class = {
 753         .name =         "hiddev%d",
 754         .fops =         &hiddev_fops,
 755         .minor_base =   HIDDEV_MINOR_BASE,
 756 };
 757
 758 /*
 759  * This is where hid.c calls us to connect a hid device to the hiddev driver
 760  */
 761 int hiddev_connect(struct hid_device *hid)
 762 {
 763         struct hiddev *hiddev;
 764         struct usbhid_device *usbhid = hid->driver_data;
 765         int i;
 766         int retval;
 767
 768         for (i = 0; i < hid->maxcollection; i++)
 769                 if (hid->collection[i].type ==
 770                     HID_COLLECTION_APPLICATION &&
 771                     !IS_INPUT_APPLICATION(hid->collection[i].usage))
 772                         break;
 773
 774         if (i == hid->maxcollection && (hid->quirks & HID_QUIRK_HIDDEV) == 0)
 775                 return -1;
 776
 777         if (!(hiddev = kzalloc(sizeof(struct hiddev), GFP_KERNEL)))
 778                 return -1;
 779
 780         retval = usb_register_dev(usbhid->intf, &hiddev_class);
 781         if (retval) {
 782                 err_hid("Not able to get a minor for this device.");
 783                 kfree(hiddev);
 784                 return -1;
 785         }
 786
 787         init_waitqueue_head(&hiddev->wait);
 788         INIT_LIST_HEAD(&hiddev->list);
 789         spin_lock_init(&hiddev->list_lock);
 790         hiddev->hid = hid;
 791         hiddev->exist = 1;
 792
 793         hid->minor = usbhid->intf->minor;
 794         hid->hiddev = hiddev;
 795
 796         hiddev_table[usbhid->intf->minor - HIDDEV_MINOR_BASE] = hiddev;
 797
 798         return 0;
 799 }
 800
 801 /*
 802  * This is where hid.c calls us to disconnect a hiddev device from the
 803  * corresponding hid device (usually because the usb device has disconnected)
 804  */
 805 static struct usb_class_driver hiddev_class;
 806 void hiddev_disconnect(struct hid_device *hid)
 807 {
 808         struct hiddev *hiddev = hid->hiddev;
 809         struct usbhid_device *usbhid = hid->driver_data;
 810
 811         hiddev->exist = 0;
 812
 813         hiddev_table[hiddev->hid->minor - HIDDEV_MINOR_BASE] = NULL;
 814         usb_deregister_dev(usbhid->intf, &hiddev_class);
 815
 816         if (hiddev->open) {
 817                 usbhid_close(hiddev->hid);
 818                 wake_up_interruptible(&hiddev->wait);
 819         } else {
 820                 kfree(hiddev);
 821         }
 822 }
 823
 824 /* Currently this driver is a USB driver.  It's not a conventional one in
 825  * the sense that it doesn't probe at the USB level.  Instead it waits to
 826  * be connected by HID through the hiddev_connect / hiddev_disconnect
 827  * routines.  The reason to register as a USB device is to gain part of the
 828  * minor number space from the USB major.
 829  *
 830  * In theory, should the HID code be generalized to more than one physical
 831  * medium (say, IEEE 1384), this driver will probably need to register its
 832  * own major number, and in doing so, no longer need to register with USB.
 833  * At that point the probe routine and hiddev_driver struct below will no
 834  * longer be useful.
 835  */
 836
 837
 838 /* We never attach in this manner, and rely on HID to connect us.  This
 839  * is why there is no disconnect routine defined in the usb_driver either.
 840  */
 841 static int hiddev_usbd_probe(struct usb_interface *intf,
 842                              const struct usb_device_id *hiddev_info)
 843 {
 844         return -ENODEV;
 845 }
 846
 847
 848 static /* const */ struct usb_driver hiddev_driver = {
 849         .name =         "hiddev",
 850         .probe =        hiddev_usbd_probe,
 851 };
 852
 853 int __init hiddev_init(void)
 854 {
 855         return usb_register(&hiddev_driver);
 856 }
 857
 858 void hiddev_exit(void)
 859 {
 860         usb_deregister(&hiddev_driver);
 861 }