git.oblomov.eu Git - linux-2.6/blob - 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 <linux/compat.h>
  38 #include "usbhid.h"
  39
  40 #ifdef CONFIG_USB_DYNAMIC_MINORS
  41 #define HIDDEV_MINOR_BASE       0
  42 #define HIDDEV_MINORS           256
  43 #else
  44 #define HIDDEV_MINOR_BASE       96
  45 #define HIDDEV_MINORS           16
  46 #endif
  47 #define HIDDEV_BUFFER_SIZE      64
  48
  49 struct hiddev {
  50         int exist;
  51         int open;
  52         wait_queue_head_t wait;
  53         struct hid_device *hid;
  54         struct list_head list;
  55         spinlock_t list_lock;
  56 };
  57
  58 struct hiddev_list {
  59         struct hiddev_usage_ref buffer[HIDDEV_BUFFER_SIZE];
  60         int head;
  61         int tail;
  62         unsigned flags;
  63         struct fasync_struct *fasync;
  64         struct hiddev *hiddev;
  65         struct list_head node;
  66 };
  67
  68 static struct hiddev *hiddev_table[HIDDEV_MINORS];
  69
  70 /*
  71  * Find a report, given the report's type and ID.  The ID can be specified
  72  * indirectly by REPORT_ID_FIRST (which returns the first report of the given
  73  * type) or by (REPORT_ID_NEXT | old_id), which returns the next report of the
  74  * given type which follows old_id.
  75  */
  76 static struct hid_report *
  77 hiddev_lookup_report(struct hid_device *hid, struct hiddev_report_info *rinfo)
  78 {
  79         unsigned int flags = rinfo->report_id & ~HID_REPORT_ID_MASK;
  80         unsigned int rid = rinfo->report_id & HID_REPORT_ID_MASK;
  81         struct hid_report_enum *report_enum;
  82         struct hid_report *report;
  83         struct list_head *list;
  84
  85         if (rinfo->report_type < HID_REPORT_TYPE_MIN ||
  86             rinfo->report_type > HID_REPORT_TYPE_MAX)
  87                 return NULL;
  88
  89         report_enum = hid->report_enum +
  90                 (rinfo->report_type - HID_REPORT_TYPE_MIN);
  91
  92         switch (flags) {
  93         case 0: /* Nothing to do -- report_id is already set correctly */
  94                 break;
  95
  96         case HID_REPORT_ID_FIRST:
  97                 if (list_empty(&report_enum->report_list))
  98                         return NULL;
  99
 100                 list = report_enum->report_list.next;
 101                 report = list_entry(list, struct hid_report, list);
 102                 rinfo->report_id = report->id;
 103                 break;
 104
 105         case HID_REPORT_ID_NEXT:
 106                 report = report_enum->report_id_hash[rid];
 107                 if (!report)
 108                         return NULL;
 109
 110                 list = report->list.next;
 111                 if (list == &report_enum->report_list)
 112                         return NULL;
 113
 114                 report = list_entry(list, struct hid_report, list);
 115                 rinfo->report_id = report->id;
 116                 break;
 117
 118         default:
 119                 return NULL;
 120         }
 121
 122         return report_enum->report_id_hash[rinfo->report_id];
 123 }
 124
 125 /*
 126  * Perform an exhaustive search of the report table for a usage, given its
 127  * type and usage id.
 128  */
 129 static struct hid_field *
 130 hiddev_lookup_usage(struct hid_device *hid, struct hiddev_usage_ref *uref)
 131 {
 132         int i, j;
 133         struct hid_report *report;
 134         struct hid_report_enum *report_enum;
 135         struct hid_field *field;
 136
 137         if (uref->report_type < HID_REPORT_TYPE_MIN ||
 138             uref->report_type > HID_REPORT_TYPE_MAX)
 139                 return NULL;
 140
 141         report_enum = hid->report_enum +
 142                 (uref->report_type - HID_REPORT_TYPE_MIN);
 143
 144         list_for_each_entry(report, &report_enum->report_list, list) {
 145                 for (i = 0; i < report->maxfield; i++) {
 146                         field = report->field[i];
 147                         for (j = 0; j < field->maxusage; j++) {
 148                                 if (field->usage[j].hid == uref->usage_code) {
 149                                         uref->report_id = report->id;
 150                                         uref->field_index = i;
 151                                         uref->usage_index = j;
 152                                         return field;
 153                                 }
 154                         }
 155                 }
 156         }
 157
 158         return NULL;
 159 }
 160
 161 static void hiddev_send_event(struct hid_device *hid,
 162                               struct hiddev_usage_ref *uref)
 163 {
 164         struct hiddev *hiddev = hid->hiddev;
 165         struct hiddev_list *list;
 166         unsigned long flags;
 167
 168         spin_lock_irqsave(&hiddev->list_lock, flags);
 169         list_for_each_entry(list, &hiddev->list, node) {
 170                 if (uref->field_index != HID_FIELD_INDEX_NONE ||
 171                     (list->flags & HIDDEV_FLAG_REPORT) != 0) {
 172                         list->buffer[list->head] = *uref;
 173                         list->head = (list->head + 1) &
 174                                 (HIDDEV_BUFFER_SIZE - 1);
 175                         kill_fasync(&list->fasync, SIGIO, POLL_IN);
 176                 }
 177         }
 178         spin_unlock_irqrestore(&hiddev->list_lock, flags);
 179
 180         wake_up_interruptible(&hiddev->wait);
 181 }
 182
 183 /*
 184  * This is where hid.c calls into hiddev to pass an event that occurred over
 185  * the interrupt pipe
 186  */
 187 void hiddev_hid_event(struct hid_device *hid, struct hid_field *field,
 188                       struct hid_usage *usage, __s32 value)
 189 {
 190         unsigned type = field->report_type;
 191         struct hiddev_usage_ref uref;
 192
 193         uref.report_type =
 194           (type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
 195           ((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
 196            ((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE : 0));
 197         uref.report_id = field->report->id;
 198         uref.field_index = field->index;
 199         uref.usage_index = (usage - field->usage);
 200         uref.usage_code = usage->hid;
 201         uref.value = value;
 202
 203         hiddev_send_event(hid, &uref);
 204 }
 205 EXPORT_SYMBOL_GPL(hiddev_hid_event);
 206
 207 void hiddev_report_event(struct hid_device *hid, struct hid_report *report)
 208 {
 209         unsigned type = report->type;
 210         struct hiddev_usage_ref uref;
 211
 212         memset(&uref, 0, sizeof(uref));
 213         uref.report_type =
 214           (type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
 215           ((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
 216            ((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE : 0));
 217         uref.report_id = report->id;
 218         uref.field_index = HID_FIELD_INDEX_NONE;
 219
 220         hiddev_send_event(hid, &uref);
 221 }
 222
 223 /*
 224  * fasync file op
 225  */
 226 static int hiddev_fasync(int fd, struct file *file, int on)
 227 {
 228         int retval;
 229         struct hiddev_list *list = file->private_data;
 230
 231         retval = fasync_helper(fd, file, on, &list->fasync);
 232
 233         return retval < 0 ? retval : 0;
 234 }
 235
 236
 237 /*
 238  * release file op
 239  */
 240 static int hiddev_release(struct inode * inode, struct file * file)
 241 {
 242         struct hiddev_list *list = file->private_data;
 243         unsigned long flags;
 244
 245         hiddev_fasync(-1, file, 0);
 246
 247         spin_lock_irqsave(&list->hiddev->list_lock, flags);
 248         list_del(&list->node);
 249         spin_unlock_irqrestore(&list->hiddev->list_lock, flags);
 250
 251         if (!--list->hiddev->open) {
 252                 if (list->hiddev->exist)
 253                         usbhid_close(list->hiddev->hid);
 254                 else
 255                         kfree(list->hiddev);
 256         }
 257
 258         kfree(list);
 259
 260         return 0;
 261 }
 262
 263 /*
 264  * open file op
 265  */
 266 static int hiddev_open(struct inode *inode, struct file *file)
 267 {
 268         struct hiddev_list *list;
 269         unsigned long flags;
 270
 271         int i = iminor(inode) - HIDDEV_MINOR_BASE;
 272
 273         if (i >= HIDDEV_MINORS || !hiddev_table[i])
 274                 return -ENODEV;
 275
 276         if (!(list = kzalloc(sizeof(struct hiddev_list), GFP_KERNEL)))
 277                 return -ENOMEM;
 278
 279         list->hiddev = hiddev_table[i];
 280
 281         spin_lock_irqsave(&list->hiddev->list_lock, flags);
 282         list_add_tail(&list->node, &hiddev_table[i]->list);
 283         spin_unlock_irqrestore(&list->hiddev->list_lock, flags);
 284
 285         file->private_data = list;
 286
 287         if (!list->hiddev->open++)
 288                 if (list->hiddev->exist)
 289                         usbhid_open(hiddev_table[i]->hid);
 290
 291         return 0;
 292 }
 293
 294 /*
 295  * "write" file op
 296  */
 297 static ssize_t hiddev_write(struct file * file, const char __user * buffer, size_t count, loff_t *ppos)
 298 {
 299         return -EINVAL;
 300 }
 301
 302 /*
 303  * "read" file op
 304  */
 305 static ssize_t hiddev_read(struct file * file, char __user * buffer, size_t count, loff_t *ppos)
 306 {
 307         DECLARE_WAITQUEUE(wait, current);
 308         struct hiddev_list *list = file->private_data;
 309         int event_size;
 310         int retval = 0;
 311
 312         event_size = ((list->flags & HIDDEV_FLAG_UREF) != 0) ?
 313                 sizeof(struct hiddev_usage_ref) : sizeof(struct hiddev_event);
 314
 315         if (count < event_size)
 316                 return 0;
 317
 318         while (retval == 0) {
 319                 if (list->head == list->tail) {
 320                         add_wait_queue(&list->hiddev->wait, &wait);
 321                         set_current_state(TASK_INTERRUPTIBLE);
 322
 323                         while (list->head == list->tail) {
 324                                 if (file->f_flags & O_NONBLOCK) {
 325                                         retval = -EAGAIN;
 326                                         break;
 327                                 }
 328                                 if (signal_pending(current)) {
 329                                         retval = -ERESTARTSYS;
 330                                         break;
 331                                 }
 332                                 if (!list->hiddev->exist) {
 333                                         retval = -EIO;
 334                                         break;
 335                                 }
 336
 337                                 schedule();
 338                                 set_current_state(TASK_INTERRUPTIBLE);
 339                         }
 340
 341                         set_current_state(TASK_RUNNING);
 342                         remove_wait_queue(&list->hiddev->wait, &wait);
 343                 }
 344
 345                 if (retval)
 346                         return retval;
 347
 348
 349                 while (list->head != list->tail &&
 350                        retval + event_size <= count) {
 351                         if ((list->flags & HIDDEV_FLAG_UREF) == 0) {
 352                                 if (list->buffer[list->tail].field_index !=
 353                                     HID_FIELD_INDEX_NONE) {
 354                                         struct hiddev_event event;
 355                                         event.hid = list->buffer[list->tail].usage_code;
 356                                         event.value = list->buffer[list->tail].value;
 357                                         if (copy_to_user(buffer + retval, &event, sizeof(struct hiddev_event)))
 358                                                 return -EFAULT;
 359                                         retval += sizeof(struct hiddev_event);
 360                                 }
 361                         } else {
 362                                 if (list->buffer[list->tail].field_index != HID_FIELD_INDEX_NONE ||
 363                                     (list->flags & HIDDEV_FLAG_REPORT) != 0) {
 364                                         if (copy_to_user(buffer + retval, list->buffer + list->tail, sizeof(struct hiddev_usage_ref)))
 365                                                 return -EFAULT;
 366                                         retval += sizeof(struct hiddev_usage_ref);
 367                                 }
 368                         }
 369                         list->tail = (list->tail + 1) & (HIDDEV_BUFFER_SIZE - 1);
 370                 }
 371
 372         }
 373
 374         return retval;
 375 }
 376
 377 /*
 378  * "poll" file op
 379  * No kernel lock - fine
 380  */
 381 static unsigned int hiddev_poll(struct file *file, poll_table *wait)
 382 {
 383         struct hiddev_list *list = file->private_data;
 384
 385         poll_wait(file, &list->hiddev->wait, wait);
 386         if (list->head != list->tail)
 387                 return POLLIN | POLLRDNORM;
 388         if (!list->hiddev->exist)
 389                 return POLLERR | POLLHUP;
 390         return 0;
 391 }
 392
 393 /*
 394  * "ioctl" file op
 395  */
 396 static int hiddev_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
 397 {
 398         struct hiddev_list *list = file->private_data;
 399         struct hiddev *hiddev = list->hiddev;
 400         struct hid_device *hid = hiddev->hid;
 401         struct usb_device *dev = hid_to_usb_dev(hid);
 402         struct hiddev_collection_info cinfo;
 403         struct hiddev_report_info rinfo;
 404         struct hiddev_field_info finfo;
 405         struct hiddev_usage_ref_multi *uref_multi = NULL;
 406         struct hiddev_usage_ref *uref;
 407         struct hiddev_devinfo dinfo;
 408         struct hid_report *report;
 409         struct hid_field *field;
 410         struct usbhid_device *usbhid = hid->driver_data;
 411         void __user *user_arg = (void __user *)arg;
 412         int i;
 413
 414         if (!hiddev->exist)
 415                 return -EIO;
 416
 417         switch (cmd) {
 418
 419         case HIDIOCGVERSION:
 420                 return put_user(HID_VERSION, (int __user *)arg);
 421
 422         case HIDIOCAPPLICATION:
 423                 if (arg < 0 || arg >= hid->maxapplication)
 424                         return -EINVAL;
 425
 426                 for (i = 0; i < hid->maxcollection; i++)
 427                         if (hid->collection[i].type ==
 428                             HID_COLLECTION_APPLICATION && arg-- == 0)
 429                                 break;
 430
 431                 if (i == hid->maxcollection)
 432                         return -EINVAL;
 433
 434                 return hid->collection[i].usage;
 435
 436         case HIDIOCGDEVINFO:
 437                 dinfo.bustype = BUS_USB;
 438                 dinfo.busnum = dev->bus->busnum;
 439                 dinfo.devnum = dev->devnum;
 440                 dinfo.ifnum = usbhid->ifnum;
 441                 dinfo.vendor = le16_to_cpu(dev->descriptor.idVendor);
 442                 dinfo.product = le16_to_cpu(dev->descriptor.idProduct);
 443                 dinfo.version = le16_to_cpu(dev->descriptor.bcdDevice);
 444                 dinfo.num_applications = hid->maxapplication;
 445                 if (copy_to_user(user_arg, &dinfo, sizeof(dinfo)))
 446                         return -EFAULT;
 447
 448                 return 0;
 449
 450         case HIDIOCGFLAG:
 451                 if (put_user(list->flags, (int __user *)arg))
 452                         return -EFAULT;
 453
 454                 return 0;
 455
 456         case HIDIOCSFLAG:
 457                 {
 458                         int newflags;
 459                         if (get_user(newflags, (int __user *)arg))
 460                                 return -EFAULT;
 461
 462                         if ((newflags & ~HIDDEV_FLAGS) != 0 ||
 463                             ((newflags & HIDDEV_FLAG_REPORT) != 0 &&
 464                              (newflags & HIDDEV_FLAG_UREF) == 0))
 465                                 return -EINVAL;
 466
 467                         list->flags = newflags;
 468
 469                         return 0;
 470                 }
 471
 472         case HIDIOCGSTRING:
 473                 {
 474                         int idx, len;
 475                         char *buf;
 476
 477                         if (get_user(idx, (int __user *)arg))
 478                                 return -EFAULT;
 479
 480                         if ((buf = kmalloc(HID_STRING_SIZE, GFP_KERNEL)) == NULL)
 481                                 return -ENOMEM;
 482
 483                         if ((len = usb_string(dev, idx, buf, HID_STRING_SIZE-1)) < 0) {
 484                                 kfree(buf);
 485                                 return -EINVAL;
 486                         }
 487
 488                         if (copy_to_user(user_arg+sizeof(int), buf, len+1)) {
 489                                 kfree(buf);
 490                                 return -EFAULT;
 491                         }
 492
 493                         kfree(buf);
 494
 495                         return len;
 496                 }
 497
 498         case HIDIOCINITREPORT:
 499                 usbhid_init_reports(hid);
 500
 501                 return 0;
 502
 503         case HIDIOCGREPORT:
 504                 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
 505                         return -EFAULT;
 506
 507                 if (rinfo.report_type == HID_REPORT_TYPE_OUTPUT)
 508                         return -EINVAL;
 509
 510                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 511                         return -EINVAL;
 512
 513                 usbhid_submit_report(hid, report, USB_DIR_IN);
 514                 usbhid_wait_io(hid);
 515
 516                 return 0;
 517
 518         case HIDIOCSREPORT:
 519                 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
 520                         return -EFAULT;
 521
 522                 if (rinfo.report_type == HID_REPORT_TYPE_INPUT)
 523                         return -EINVAL;
 524
 525                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 526                         return -EINVAL;
 527
 528                 usbhid_submit_report(hid, report, USB_DIR_OUT);
 529                 usbhid_wait_io(hid);
 530
 531                 return 0;
 532
 533         case HIDIOCGREPORTINFO:
 534                 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
 535                         return -EFAULT;
 536
 537                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 538                         return -EINVAL;
 539
 540                 rinfo.num_fields = report->maxfield;
 541
 542                 if (copy_to_user(user_arg, &rinfo, sizeof(rinfo)))
 543                         return -EFAULT;
 544
 545                 return 0;
 546
 547         case HIDIOCGFIELDINFO:
 548                 if (copy_from_user(&finfo, user_arg, sizeof(finfo)))
 549                         return -EFAULT;
 550                 rinfo.report_type = finfo.report_type;
 551                 rinfo.report_id = finfo.report_id;
 552                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 553                         return -EINVAL;
 554
 555                 if (finfo.field_index >= report->maxfield)
 556                         return -EINVAL;
 557
 558                 field = report->field[finfo.field_index];
 559                 memset(&finfo, 0, sizeof(finfo));
 560                 finfo.report_type = rinfo.report_type;
 561                 finfo.report_id = rinfo.report_id;
 562                 finfo.field_index = field->report_count - 1;
 563                 finfo.maxusage = field->maxusage;
 564                 finfo.flags = field->flags;
 565                 finfo.physical = field->physical;
 566                 finfo.logical = field->logical;
 567                 finfo.application = field->application;
 568                 finfo.logical_minimum = field->logical_minimum;
 569                 finfo.logical_maximum = field->logical_maximum;
 570                 finfo.physical_minimum = field->physical_minimum;
 571                 finfo.physical_maximum = field->physical_maximum;
 572                 finfo.unit_exponent = field->unit_exponent;
 573                 finfo.unit = field->unit;
 574
 575                 if (copy_to_user(user_arg, &finfo, sizeof(finfo)))
 576                         return -EFAULT;
 577
 578                 return 0;
 579
 580         case HIDIOCGUCODE:
 581                 uref_multi = kmalloc(sizeof(struct hiddev_usage_ref_multi), GFP_KERNEL);
 582                 if (!uref_multi)
 583                         return -ENOMEM;
 584                 uref = &uref_multi->uref;
 585                 if (copy_from_user(uref, user_arg, sizeof(*uref)))
 586                         goto fault;
 587
 588                 rinfo.report_type = uref->report_type;
 589                 rinfo.report_id = uref->report_id;
 590                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 591                         goto inval;
 592
 593                 if (uref->field_index >= report->maxfield)
 594                         goto inval;
 595
 596                 field = report->field[uref->field_index];
 597                 if (uref->usage_index >= field->maxusage)
 598                         goto inval;
 599
 600                 uref->usage_code = field->usage[uref->usage_index].hid;
 601
 602                 if (copy_to_user(user_arg, uref, sizeof(*uref)))
 603                         goto fault;
 604
 605                 kfree(uref_multi);
 606                 return 0;
 607
 608         case HIDIOCGUSAGE:
 609         case HIDIOCSUSAGE:
 610         case HIDIOCGUSAGES:
 611         case HIDIOCSUSAGES:
 612         case HIDIOCGCOLLECTIONINDEX:
 613                 uref_multi = kmalloc(sizeof(struct hiddev_usage_ref_multi), GFP_KERNEL);
 614                 if (!uref_multi)
 615                         return -ENOMEM;
 616                 uref = &uref_multi->uref;
 617                 if (cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) {
 618                         if (copy_from_user(uref_multi, user_arg,
 619                                            sizeof(*uref_multi)))
 620                                 goto fault;
 621                 } else {
 622                         if (copy_from_user(uref, user_arg, sizeof(*uref)))
 623                                 goto fault;
 624                 }
 625
 626                 if (cmd != HIDIOCGUSAGE &&
 627                     cmd != HIDIOCGUSAGES &&
 628                     uref->report_type == HID_REPORT_TYPE_INPUT)
 629                         goto inval;
 630
 631                 if (uref->report_id == HID_REPORT_ID_UNKNOWN) {
 632                         field = hiddev_lookup_usage(hid, uref);
 633                         if (field == NULL)
 634                                 goto inval;
 635                 } else {
 636                         rinfo.report_type = uref->report_type;
 637                         rinfo.report_id = uref->report_id;
 638                         if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 639                                 goto inval;
 640
 641                         if (uref->field_index >= report->maxfield)
 642                                 goto inval;
 643
 644                         field = report->field[uref->field_index];
 645
 646                         if (cmd == HIDIOCGCOLLECTIONINDEX) {
 647                                 if (uref->usage_index >= field->maxusage)
 648                                         goto inval;
 649                         } else if (uref->usage_index >= field->report_count)
 650                                 goto inval;
 651
 652                         else if ((cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) &&
 653                                  (uref_multi->num_values > HID_MAX_MULTI_USAGES ||
 654                                   uref->usage_index + uref_multi->num_values > field->report_count))
 655                                 goto inval;
 656                         }
 657
 658                 switch (cmd) {
 659                         case HIDIOCGUSAGE:
 660                                 uref->value = field->value[uref->usage_index];
 661                                 if (copy_to_user(user_arg, uref, sizeof(*uref)))
 662                                         goto fault;
 663                                 goto goodreturn;
 664
 665                         case HIDIOCSUSAGE:
 666                                 field->value[uref->usage_index] = uref->value;
 667                                 goto goodreturn;
 668
 669                         case HIDIOCGCOLLECTIONINDEX:
 670                                 kfree(uref_multi);
 671                                 return field->usage[uref->usage_index].collection_index;
 672                         case HIDIOCGUSAGES:
 673                                 for (i = 0; i < uref_multi->num_values; i++)
 674                                         uref_multi->values[i] =
 675                                             field->value[uref->usage_index + i];
 676                                 if (copy_to_user(user_arg, uref_multi,
 677                                                  sizeof(*uref_multi)))
 678                                         goto fault;
 679                                 goto goodreturn;
 680                         case HIDIOCSUSAGES:
 681                                 for (i = 0; i < uref_multi->num_values; i++)
 682                                         field->value[uref->usage_index + i] =
 683                                             uref_multi->values[i];
 684                                 goto goodreturn;
 685                 }
 686
 687 goodreturn:
 688                 kfree(uref_multi);
 689                 return 0;
 690 fault:
 691                 kfree(uref_multi);
 692                 return -EFAULT;
 693 inval:
 694                 kfree(uref_multi);
 695                 return -EINVAL;
 696
 697         case HIDIOCGCOLLECTIONINFO:
 698                 if (copy_from_user(&cinfo, user_arg, sizeof(cinfo)))
 699                         return -EFAULT;
 700
 701                 if (cinfo.index >= hid->maxcollection)
 702                         return -EINVAL;
 703
 704                 cinfo.type = hid->collection[cinfo.index].type;
 705                 cinfo.usage = hid->collection[cinfo.index].usage;
 706                 cinfo.level = hid->collection[cinfo.index].level;
 707
 708                 if (copy_to_user(user_arg, &cinfo, sizeof(cinfo)))
 709                         return -EFAULT;
 710                 return 0;
 711
 712         default:
 713
 714                 if (_IOC_TYPE(cmd) != 'H' || _IOC_DIR(cmd) != _IOC_READ)
 715                         return -EINVAL;
 716
 717                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGNAME(0))) {
 718                         int len;
 719                         if (!hid->name)
 720                                 return 0;
 721                         len = strlen(hid->name) + 1;
 722                         if (len > _IOC_SIZE(cmd))
 723                                  len = _IOC_SIZE(cmd);
 724                         return copy_to_user(user_arg, hid->name, len) ?
 725                                 -EFAULT : len;
 726                 }
 727
 728                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGPHYS(0))) {
 729                         int len;
 730                         if (!hid->phys)
 731                                 return 0;
 732                         len = strlen(hid->phys) + 1;
 733                         if (len > _IOC_SIZE(cmd))
 734                                 len = _IOC_SIZE(cmd);
 735                         return copy_to_user(user_arg, hid->phys, len) ?
 736                                 -EFAULT : len;
 737                 }
 738         }
 739         return -EINVAL;
 740 }
 741
 742 #ifdef CONFIG_COMPAT
 743 static long hiddev_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 744 {
 745         struct inode *inode = file->f_path.dentry->d_inode;
 746         return hiddev_ioctl(inode, file, cmd, compat_ptr(arg));
 747 }
 748 #endif
 749
 750 static const struct file_operations hiddev_fops = {
 751         .owner =        THIS_MODULE,
 752         .read =         hiddev_read,
 753         .write =        hiddev_write,
 754         .poll =         hiddev_poll,
 755         .open =         hiddev_open,
 756         .release =      hiddev_release,
 757         .ioctl =        hiddev_ioctl,
 758         .fasync =       hiddev_fasync,
 759 #ifdef CONFIG_COMPAT
 760         .compat_ioctl   = hiddev_compat_ioctl,
 761 #endif
 762 };
 763
 764 static struct usb_class_driver hiddev_class = {
 765         .name =         "hiddev%d",
 766         .fops =         &hiddev_fops,
 767         .minor_base =   HIDDEV_MINOR_BASE,
 768 };
 769
 770 /*
 771  * This is where hid.c calls us to connect a hid device to the hiddev driver
 772  */
 773 int hiddev_connect(struct hid_device *hid)
 774 {
 775         struct hiddev *hiddev;
 776         struct usbhid_device *usbhid = hid->driver_data;
 777         int i;
 778         int retval;
 779
 780         for (i = 0; i < hid->maxcollection; i++)
 781                 if (hid->collection[i].type ==
 782                     HID_COLLECTION_APPLICATION &&
 783                     !IS_INPUT_APPLICATION(hid->collection[i].usage))
 784                         break;
 785
 786         if (i == hid->maxcollection && (hid->quirks & HID_QUIRK_HIDDEV) == 0)
 787                 return -1;
 788
 789         if (!(hiddev = kzalloc(sizeof(struct hiddev), GFP_KERNEL)))
 790                 return -1;
 791
 792         retval = usb_register_dev(usbhid->intf, &hiddev_class);
 793         if (retval) {
 794                 err_hid("Not able to get a minor for this device.");
 795                 kfree(hiddev);
 796                 return -1;
 797         }
 798
 799         init_waitqueue_head(&hiddev->wait);
 800         INIT_LIST_HEAD(&hiddev->list);
 801         spin_lock_init(&hiddev->list_lock);
 802         hiddev->hid = hid;
 803         hiddev->exist = 1;
 804
 805         hid->minor = usbhid->intf->minor;
 806         hid->hiddev = hiddev;
 807
 808         hiddev_table[usbhid->intf->minor - HIDDEV_MINOR_BASE] = hiddev;
 809
 810         return 0;
 811 }
 812
 813 /*
 814  * This is where hid.c calls us to disconnect a hiddev device from the
 815  * corresponding hid device (usually because the usb device has disconnected)
 816  */
 817 static struct usb_class_driver hiddev_class;
 818 void hiddev_disconnect(struct hid_device *hid)
 819 {
 820         struct hiddev *hiddev = hid->hiddev;
 821         struct usbhid_device *usbhid = hid->driver_data;
 822
 823         hiddev->exist = 0;
 824
 825         hiddev_table[hiddev->hid->minor - HIDDEV_MINOR_BASE] = NULL;
 826         usb_deregister_dev(usbhid->intf, &hiddev_class);
 827
 828         if (hiddev->open) {
 829                 usbhid_close(hiddev->hid);
 830                 wake_up_interruptible(&hiddev->wait);
 831         } else {
 832                 kfree(hiddev);
 833         }
 834 }
 835
 836 /* Currently this driver is a USB driver.  It's not a conventional one in
 837  * the sense that it doesn't probe at the USB level.  Instead it waits to
 838  * be connected by HID through the hiddev_connect / hiddev_disconnect
 839  * routines.  The reason to register as a USB device is to gain part of the
 840  * minor number space from the USB major.
 841  *
 842  * In theory, should the HID code be generalized to more than one physical
 843  * medium (say, IEEE 1384), this driver will probably need to register its
 844  * own major number, and in doing so, no longer need to register with USB.
 845  * At that point the probe routine and hiddev_driver struct below will no
 846  * longer be useful.
 847  */
 848
 849
 850 /* We never attach in this manner, and rely on HID to connect us.  This
 851  * is why there is no disconnect routine defined in the usb_driver either.
 852  */
 853 static int hiddev_usbd_probe(struct usb_interface *intf,
 854                              const struct usb_device_id *hiddev_info)
 855 {
 856         return -ENODEV;
 857 }
 858
 859
 860 static /* const */ struct usb_driver hiddev_driver = {
 861         .name =         "hiddev",
 862         .probe =        hiddev_usbd_probe,
 863 };
 864
 865 int __init hiddev_init(void)
 866 {
 867         return usb_register(&hiddev_driver);
 868 }
 869
 870 void hiddev_exit(void)
 871 {
 872         usb_deregister(&hiddev_driver);
 873 }