drivers/usb/input/hiddev.c

   1 /*
   2  *  Copyright (c) 2001 Paul Stewart
   3  *  Copyright (c) 2001 Vojtech Pavlik
   4  *
   5  *  HID char devices, giving access to raw HID device events.
   6  *
   7  */
   8
   9 /*
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  23  *
  24  * Should you need to contact me, the author, you can do so either by
  25  * e-mail - mail your message to Paul Stewart <stewart@wetlogic.net>
  26  */
  27
  28 #include <linux/config.h>
  29 #include <linux/poll.h>
  30 #include <linux/slab.h>
  31 #include <linux/module.h>
  32 #include <linux/init.h>
  33 #include <linux/smp_lock.h>
  34 #include <linux/input.h>
  35 #include <linux/usb.h>
  36 #include "hid.h"
  37 #include <linux/hiddev.h>
  38 #include <linux/devfs_fs_kernel.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 hiddev_list *list;
  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 hiddev_list *next;
  65 };
  66
  67 static struct hiddev *hiddev_table[HIDDEV_MINORS];
  68
  69 /* forward reference to make our lives easier */
  70 extern struct usb_driver hiddev_driver;
  71
  72 /*
  73  * Find a report, given the report's type and ID.  The ID can be specified
  74  * indirectly by REPORT_ID_FIRST (which returns the first report of the given
  75  * type) or by (REPORT_ID_NEXT | old_id), which returns the next report of the
  76  * given type which follows old_id.
  77  */
  78 static struct hid_report *
  79 hiddev_lookup_report(struct hid_device *hid, struct hiddev_report_info *rinfo)
  80 {
  81         unsigned flags = rinfo->report_id & ~HID_REPORT_ID_MASK;
  82         struct hid_report_enum *report_enum;
  83         struct list_head *list;
  84
  85         if (rinfo->report_type < HID_REPORT_TYPE_MIN ||
  86             rinfo->report_type > HID_REPORT_TYPE_MAX) 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                 list = report_enum->report_list.next;
  97                 if (list == &report_enum->report_list)
  98                         return NULL;
  99                 rinfo->report_id = ((struct hid_report *) list)->id;
 100                 break;
 101
 102         case HID_REPORT_ID_NEXT:
 103                 list = (struct list_head *)
 104                         report_enum->report_id_hash[rinfo->report_id & HID_REPORT_ID_MASK];
 105                 if (list == NULL)
 106                         return NULL;
 107                 list = list->next;
 108                 if (list == &report_enum->report_list)
 109                         return NULL;
 110                 rinfo->report_id = ((struct hid_report *) list)->id;
 111                 break;
 112
 113         default:
 114                 return NULL;
 115         }
 116
 117         return report_enum->report_id_hash[rinfo->report_id];
 118 }
 119
 120 /*
 121  * Perform an exhaustive search of the report table for a usage, given its
 122  * type and usage id.
 123  */
 124 static struct hid_field *
 125 hiddev_lookup_usage(struct hid_device *hid, struct hiddev_usage_ref *uref)
 126 {
 127         int i, j;
 128         struct hid_report *report;
 129         struct hid_report_enum *report_enum;
 130         struct list_head *list;
 131         struct hid_field *field;
 132
 133         if (uref->report_type < HID_REPORT_TYPE_MIN ||
 134             uref->report_type > HID_REPORT_TYPE_MAX) return NULL;
 135
 136         report_enum = hid->report_enum +
 137                 (uref->report_type - HID_REPORT_TYPE_MIN);
 138         list = report_enum->report_list.next;
 139         while (list != &report_enum->report_list) {
 140                 report = (struct hid_report *) list;
 141                 for (i = 0; i < report->maxfield; i++) {
 142                         field = report->field[i];
 143                         for (j = 0; j < field->maxusage; j++) {
 144                                 if (field->usage[j].hid == uref->usage_code) {
 145                                         uref->report_id = report->id;
 146                                         uref->field_index = i;
 147                                         uref->usage_index = j;
 148                                         return field;
 149                                 }
 150                         }
 151                 }
 152                 list = list->next;
 153         }
 154
 155         return NULL;
 156 }
 157
 158 static void hiddev_send_event(struct hid_device *hid,
 159                               struct hiddev_usage_ref *uref)
 160 {
 161         struct hiddev *hiddev = hid->hiddev;
 162         struct hiddev_list *list = hiddev->list;
 163
 164         while (list) {
 165                 if (uref->field_index != HID_FIELD_INDEX_NONE ||
 166                     (list->flags & HIDDEV_FLAG_REPORT) != 0) {
 167                         list->buffer[list->head] = *uref;
 168                         list->head = (list->head + 1) &
 169                                 (HIDDEV_BUFFER_SIZE - 1);
 170                         kill_fasync(&list->fasync, SIGIO, POLL_IN);
 171                 }
 172
 173                 list = list->next;
 174         }
 175
 176         wake_up_interruptible(&hiddev->wait);
 177 }
 178
 179 /*
 180  * This is where hid.c calls into hiddev to pass an event that occurred over
 181  * the interrupt pipe
 182  */
 183 void hiddev_hid_event(struct hid_device *hid, struct hid_field *field,
 184                       struct hid_usage *usage, __s32 value, struct pt_regs *regs)
 185 {
 186         unsigned type = field->report_type;
 187         struct hiddev_usage_ref uref;
 188
 189         uref.report_type =
 190           (type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
 191           ((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
 192            ((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE:0));
 193         uref.report_id = field->report->id;
 194         uref.field_index = field->index;
 195         uref.usage_index = (usage - field->usage);
 196         uref.usage_code = usage->hid;
 197         uref.value = value;
 198
 199         hiddev_send_event(hid, &uref);
 200 }
 201
 202
 203 void hiddev_report_event(struct hid_device *hid, struct hid_report *report)
 204 {
 205         unsigned type = report->type;
 206         struct hiddev_usage_ref uref;
 207
 208         memset(&uref, 0, sizeof(uref));
 209         uref.report_type =
 210           (type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
 211           ((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
 212            ((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE:0));
 213         uref.report_id = report->id;
 214         uref.field_index = HID_FIELD_INDEX_NONE;
 215
 216         hiddev_send_event(hid, &uref);
 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         retval = fasync_helper(fd, file, on, &list->fasync);
 226         return retval < 0 ? retval : 0;
 227 }
 228
 229 /*
 230  * De-allocate a hiddev structure
 231  */
 232 static struct usb_class_driver hiddev_class;
 233 static void hiddev_cleanup(struct hiddev *hiddev)
 234 {
 235         hiddev_table[hiddev->hid->minor - HIDDEV_MINOR_BASE] = NULL;
 236         usb_deregister_dev(hiddev->hid->intf, &hiddev_class);
 237         kfree(hiddev);
 238 }
 239
 240 /*
 241  * release file op
 242  */
 243 static int hiddev_release(struct inode * inode, struct file * file)
 244 {
 245         struct hiddev_list *list = file->private_data;
 246         struct hiddev_list **listptr;
 247
 248         listptr = &list->hiddev->list;
 249         hiddev_fasync(-1, file, 0);
 250
 251         while (*listptr && (*listptr != list))
 252                 listptr = &((*listptr)->next);
 253         *listptr = (*listptr)->next;
 254
 255         if (!--list->hiddev->open) {
 256                 if (list->hiddev->exist)
 257                         hid_close(list->hiddev->hid);
 258                 else
 259                         hiddev_cleanup(list->hiddev);
 260         }
 261
 262         kfree(list);
 263
 264         return 0;
 265 }
 266
 267 /*
 268  * open file op
 269  */
 270 static int hiddev_open(struct inode * inode, struct file * file) {
 271         struct hiddev_list *list;
 272
 273         int i = iminor(inode) - HIDDEV_MINOR_BASE;
 274
 275         if (i >= HIDDEV_MINORS || !hiddev_table[i])
 276                 return -ENODEV;
 277
 278         if (!(list = kmalloc(sizeof(struct hiddev_list), GFP_KERNEL)))
 279                 return -ENOMEM;
 280         memset(list, 0, sizeof(struct hiddev_list));
 281
 282         list->hiddev = hiddev_table[i];
 283         list->next = hiddev_table[i]->list;
 284         hiddev_table[i]->list = list;
 285
 286         file->private_data = list;
 287
 288         if (!list->hiddev->open++)
 289                 if (list->hiddev->exist)
 290                         hid_open(hiddev_table[i]->hid);
 291
 292         return 0;
 293 }
 294
 295 /*
 296  * "write" file op
 297  */
 298 static ssize_t hiddev_write(struct file * file, const char __user * buffer, size_t count, loff_t *ppos)
 299 {
 300         return -EINVAL;
 301 }
 302
 303 /*
 304  * "read" file op
 305  */
 306 static ssize_t hiddev_read(struct file * file, char __user * buffer, size_t count, loff_t *ppos)
 307 {
 308         DECLARE_WAITQUEUE(wait, current);
 309         struct hiddev_list *list = file->private_data;
 310         int event_size;
 311         int retval = 0;
 312
 313         event_size = ((list->flags & HIDDEV_FLAG_UREF) != 0) ?
 314                 sizeof(struct hiddev_usage_ref) : sizeof(struct hiddev_event);
 315
 316         if (count < event_size)
 317                 return 0;
 318
 319         while (retval == 0) {
 320                 if (list->head == list->tail) {
 321                         add_wait_queue(&list->hiddev->wait, &wait);
 322                         set_current_state(TASK_INTERRUPTIBLE);
 323
 324                         while (list->head == list->tail) {
 325                                 if (file->f_flags & O_NONBLOCK) {
 326                                         retval = -EAGAIN;
 327                                         break;
 328                                 }
 329                                 if (signal_pending(current)) {
 330                                         retval = -ERESTARTSYS;
 331                                         break;
 332                                 }
 333                                 if (!list->hiddev->exist) {
 334                                         retval = -EIO;
 335                                         break;
 336                                 }
 337
 338                                 schedule();
 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         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->dev;
 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         void __user *user_arg = (void __user *)arg;
 410         int i;
 411
 412         if (!hiddev->exist)
 413                 return -EIO;
 414
 415         switch (cmd) {
 416
 417         case HIDIOCGVERSION:
 418                 return put_user(HID_VERSION, (int __user *)arg);
 419
 420         case HIDIOCAPPLICATION:
 421                 if (arg < 0 || arg >= hid->maxapplication)
 422                         return -EINVAL;
 423
 424                 for (i = 0; i < hid->maxcollection; i++)
 425                         if (hid->collection[i].type ==
 426                             HID_COLLECTION_APPLICATION && arg-- == 0)
 427                                 break;
 428
 429                 if (i == hid->maxcollection)
 430                         return -EINVAL;
 431
 432                 return hid->collection[i].usage;
 433
 434         case HIDIOCGDEVINFO:
 435                 dinfo.bustype = BUS_USB;
 436                 dinfo.busnum = dev->bus->busnum;
 437                 dinfo.devnum = dev->devnum;
 438                 dinfo.ifnum = hid->ifnum;
 439                 dinfo.vendor = dev->descriptor.idVendor;
 440                 dinfo.product = dev->descriptor.idProduct;
 441                 dinfo.version = dev->descriptor.bcdDevice;
 442                 dinfo.num_applications = hid->maxapplication;
 443                 if (copy_to_user(user_arg, &dinfo, sizeof(dinfo)))
 444                         return -EFAULT;
 445
 446                 return 0;
 447
 448         case HIDIOCGFLAG:
 449                 if (put_user(list->flags, (int __user *)arg))
 450                         return -EFAULT;
 451
 452                 return 0;
 453
 454         case HIDIOCSFLAG:
 455                 {
 456                         int newflags;
 457                         if (get_user(newflags, (int __user *)arg))
 458                                 return -EFAULT;
 459
 460                         if ((newflags & ~HIDDEV_FLAGS) != 0 ||
 461                             ((newflags & HIDDEV_FLAG_REPORT) != 0 &&
 462                              (newflags & HIDDEV_FLAG_UREF) == 0))
 463                                 return -EINVAL;
 464
 465                         list->flags = newflags;
 466
 467                         return 0;
 468                 }
 469
 470         case HIDIOCGSTRING:
 471                 {
 472                         int idx, len;
 473                         char *buf;
 474
 475                         if (get_user(idx, (int __user *)arg))
 476                                 return -EFAULT;
 477
 478                         if ((buf = kmalloc(HID_STRING_SIZE, GFP_KERNEL)) == NULL)
 479                                 return -ENOMEM;
 480
 481                         if ((len = usb_string(dev, idx, buf, HID_STRING_SIZE-1)) < 0) {
 482                                 kfree(buf);
 483                                 return -EINVAL;
 484                         }
 485
 486                         if (copy_to_user(user_arg+sizeof(int), buf, len+1)) {
 487                                 kfree(buf);
 488                                 return -EFAULT;
 489                         }
 490
 491                         kfree(buf);
 492
 493                         return len;
 494                 }
 495
 496         case HIDIOCINITREPORT:
 497                 hid_init_reports(hid);
 498
 499                 return 0;
 500
 501         case HIDIOCGREPORT:
 502                 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
 503                         return -EFAULT;
 504
 505                 if (rinfo.report_type == HID_REPORT_TYPE_OUTPUT)
 506                         return -EINVAL;
 507
 508                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 509                         return -EINVAL;
 510
 511                 hid_submit_report(hid, report, USB_DIR_IN);
 512                 hid_wait_io(hid);
 513
 514                 return 0;
 515
 516         case HIDIOCSREPORT:
 517                 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
 518                         return -EFAULT;
 519
 520                 if (rinfo.report_type == HID_REPORT_TYPE_INPUT)
 521                         return -EINVAL;
 522
 523                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 524                         return -EINVAL;
 525
 526                 hid_submit_report(hid, report, USB_DIR_OUT);
 527
 528                 return 0;
 529
 530         case HIDIOCGREPORTINFO:
 531                 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
 532                         return -EFAULT;
 533
 534                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 535                         return -EINVAL;
 536
 537                 rinfo.num_fields = report->maxfield;
 538
 539                 if (copy_to_user(user_arg, &rinfo, sizeof(rinfo)))
 540                         return -EFAULT;
 541
 542                 return 0;
 543
 544         case HIDIOCGFIELDINFO:
 545                 if (copy_from_user(&finfo, user_arg, sizeof(finfo)))
 546                         return -EFAULT;
 547                 rinfo.report_type = finfo.report_type;
 548                 rinfo.report_id = finfo.report_id;
 549                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 550                         return -EINVAL;
 551
 552                 if (finfo.field_index >= report->maxfield)
 553                         return -EINVAL;
 554
 555                 field = report->field[finfo.field_index];
 556                 memset(&finfo, 0, sizeof(finfo));
 557                 finfo.report_type = rinfo.report_type;
 558                 finfo.report_id = rinfo.report_id;
 559                 finfo.field_index = field->report_count - 1;
 560                 finfo.maxusage = field->maxusage;
 561                 finfo.flags = field->flags;
 562                 finfo.physical = field->physical;
 563                 finfo.logical = field->logical;
 564                 finfo.application = field->application;
 565                 finfo.logical_minimum = field->logical_minimum;
 566                 finfo.logical_maximum = field->logical_maximum;
 567                 finfo.physical_minimum = field->physical_minimum;
 568                 finfo.physical_maximum = field->physical_maximum;
 569                 finfo.unit_exponent = field->unit_exponent;
 570                 finfo.unit = field->unit;
 571
 572                 if (copy_to_user(user_arg, &finfo, sizeof(finfo)))
 573                         return -EFAULT;
 574
 575                 return 0;
 576
 577         case HIDIOCGUCODE:
 578                 uref_multi = kmalloc(sizeof(struct hiddev_usage_ref_multi), GFP_KERNEL);
 579                 if (!uref_multi)
 580                         return -ENOMEM;
 581                 uref = &uref_multi->uref;
 582                 if (copy_from_user(uref, user_arg, sizeof(*uref)))
 583                         goto fault;
 584
 585                 rinfo.report_type = uref->report_type;
 586                 rinfo.report_id = uref->report_id;
 587                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 588                         goto inval;
 589
 590                 if (uref->field_index >= report->maxfield)
 591                         goto inval;
 592
 593                 field = report->field[uref->field_index];
 594                 if (uref->usage_index >= field->maxusage)
 595                         goto inval;
 596
 597                 uref->usage_code = field->usage[uref->usage_index].hid;
 598
 599                 if (copy_to_user(user_arg, uref, sizeof(*uref)))
 600                         goto fault;
 601
 602                 kfree(uref_multi);
 603                 return 0;
 604
 605         case HIDIOCGUSAGE:
 606         case HIDIOCSUSAGE:
 607         case HIDIOCGUSAGES:
 608         case HIDIOCSUSAGES:
 609         case HIDIOCGCOLLECTIONINDEX:
 610                 uref_multi = kmalloc(sizeof(struct hiddev_usage_ref_multi), GFP_KERNEL);
 611                 if (!uref_multi)
 612                         return -ENOMEM;
 613                 uref = &uref_multi->uref;
 614                 if (cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) {
 615                         if (copy_from_user(uref_multi, user_arg,
 616                                            sizeof(*uref_multi)))
 617                                 goto fault;
 618                 } else {
 619                         if (copy_from_user(uref, user_arg, sizeof(*uref)))
 620                                 goto fault;
 621                 }
 622
 623                 if (cmd != HIDIOCGUSAGE &&
 624                     cmd != HIDIOCGUSAGES &&
 625                     uref->report_type == HID_REPORT_TYPE_INPUT)
 626                         goto inval;
 627
 628                 if (uref->report_id == HID_REPORT_ID_UNKNOWN) {
 629                         field = hiddev_lookup_usage(hid, uref);
 630                         if (field == NULL)
 631                                 goto inval;
 632                 } else {
 633                         rinfo.report_type = uref->report_type;
 634                         rinfo.report_id = uref->report_id;
 635                         if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 636                                 goto inval;
 637
 638                         if (uref->field_index >= report->maxfield)
 639                                 goto inval;
 640
 641                         field = report->field[uref->field_index];
 642                         if (uref->usage_index >= field->maxusage)
 643                                 goto inval;
 644
 645                         if (cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) {
 646                                 if (uref_multi->num_values >= HID_MAX_USAGES ||
 647                                     uref->usage_index >= field->maxusage ||
 648                                    (uref->usage_index + uref_multi->num_values) >= field->maxusage)
 649                                         goto inval;
 650                         }
 651                 }
 652
 653                 switch (cmd) {
 654                         case HIDIOCGUSAGE:
 655                                 uref->value = field->value[uref->usage_index];
 656                                 if (copy_to_user(user_arg, uref, sizeof(*uref)))
 657                                         goto fault;
 658                                 goto goodreturn;
 659
 660                         case HIDIOCSUSAGE:
 661                                 field->value[uref->usage_index] = uref->value;
 662                                 goto goodreturn;
 663
 664                         case HIDIOCGCOLLECTIONINDEX:
 665                                 kfree(uref_multi);
 666                                 return field->usage[uref->usage_index].collection_index;
 667                         case HIDIOCGUSAGES:
 668                                 for (i = 0; i < uref_multi->num_values; i++)
 669                                         uref_multi->values[i] =
 670                                             field->value[uref->usage_index + i];
 671                                 if (copy_to_user(user_arg, uref_multi,
 672                                                  sizeof(*uref_multi)))
 673                                         goto fault;
 674                                 goto goodreturn;
 675                         case HIDIOCSUSAGES:
 676                                 for (i = 0; i < uref_multi->num_values; i++)
 677                                         field->value[uref->usage_index + i] =
 678                                             uref_multi->values[i];
 679                                 goto goodreturn;
 680                 }
 681
 682 goodreturn:
 683                 kfree(uref_multi);
 684                 return 0;
 685 fault:
 686                 kfree(uref_multi);
 687                 return -EFAULT;
 688 inval:
 689                 kfree(uref_multi);
 690                 return -EINVAL;
 691
 692         case HIDIOCGCOLLECTIONINFO:
 693                 if (copy_from_user(&cinfo, user_arg, sizeof(cinfo)))
 694                         return -EFAULT;
 695
 696                 if (cinfo.index >= hid->maxcollection)
 697                         return -EINVAL;
 698
 699                 cinfo.type = hid->collection[cinfo.index].type;
 700                 cinfo.usage = hid->collection[cinfo.index].usage;
 701                 cinfo.level = hid->collection[cinfo.index].level;
 702
 703                 if (copy_to_user(user_arg, &cinfo, sizeof(cinfo)))
 704                         return -EFAULT;
 705                 return 0;
 706
 707         default:
 708
 709                 if (_IOC_TYPE(cmd) != 'H' || _IOC_DIR(cmd) != _IOC_READ)
 710                         return -EINVAL;
 711
 712                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGNAME(0))) {
 713                         int len;
 714                         if (!hid->name)
 715                                 return 0;
 716                         len = strlen(hid->name) + 1;
 717                         if (len > _IOC_SIZE(cmd))
 718                                  len = _IOC_SIZE(cmd);
 719                         return copy_to_user(user_arg, hid->name, len) ?
 720                                 -EFAULT : len;
 721                 }
 722
 723                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGPHYS(0))) {
 724                         int len;
 725                         if (!hid->phys)
 726                                 return 0;
 727                         len = strlen(hid->phys) + 1;
 728                         if (len > _IOC_SIZE(cmd))
 729                                 len = _IOC_SIZE(cmd);
 730                         return copy_to_user(user_arg, hid->phys, len) ?
 731                                 -EFAULT : len;
 732                 }
 733         }
 734         return -EINVAL;
 735 }
 736
 737 static struct file_operations hiddev_fops = {
 738         .owner =        THIS_MODULE,
 739         .read =         hiddev_read,
 740         .write =        hiddev_write,
 741         .poll =         hiddev_poll,
 742         .open =         hiddev_open,
 743         .release =      hiddev_release,
 744         .ioctl =        hiddev_ioctl,
 745         .fasync =       hiddev_fasync,
 746 };
 747
 748 static struct usb_class_driver hiddev_class = {
 749         .name =         "usb/hid/hiddev%d",
 750         .fops =         &hiddev_fops,
 751         .mode =         S_IFCHR | S_IRUGO | S_IWUSR,
 752         .minor_base =   HIDDEV_MINOR_BASE,
 753 };
 754
 755 /*
 756  * This is where hid.c calls us to connect a hid device to the hiddev driver
 757  */
 758 int hiddev_connect(struct hid_device *hid)
 759 {
 760         struct hiddev *hiddev;
 761         int i;
 762         int retval;
 763
 764         for (i = 0; i < hid->maxcollection; i++)
 765                 if (hid->collection[i].type ==
 766                     HID_COLLECTION_APPLICATION &&
 767                     !IS_INPUT_APPLICATION(hid->collection[i].usage))
 768                         break;
 769
 770         if (i == hid->maxcollection && (hid->quirks & HID_QUIRK_HIDDEV) == 0)
 771                 return -1;
 772
 773         if (!(hiddev = kmalloc(sizeof(struct hiddev), GFP_KERNEL)))
 774                 return -1;
 775         memset(hiddev, 0, sizeof(struct hiddev));
 776
 777         retval = usb_register_dev(hid->intf, &hiddev_class);
 778         if (retval) {
 779                 err("Not able to get a minor for this device.");
 780                 kfree(hiddev);
 781                 return -1;
 782         }
 783
 784         init_waitqueue_head(&hiddev->wait);
 785
 786         hiddev_table[hid->intf->minor - HIDDEV_MINOR_BASE] = hiddev;
 787
 788         hiddev->hid = hid;
 789         hiddev->exist = 1;
 790
 791         hid->minor = hid->intf->minor;
 792         hid->hiddev = hiddev;
 793
 794         return 0;
 795 }
 796
 797 /*
 798  * This is where hid.c calls us to disconnect a hiddev device from the
 799  * corresponding hid device (usually because the usb device has disconnected)
 800  */
 801 void hiddev_disconnect(struct hid_device *hid)
 802 {
 803         struct hiddev *hiddev = hid->hiddev;
 804
 805         hiddev->exist = 0;
 806
 807         if (hiddev->open) {
 808                 hid_close(hiddev->hid);
 809                 wake_up_interruptible(&hiddev->wait);
 810         } else {
 811                 hiddev_cleanup(hiddev);
 812         }
 813 }
 814
 815 /* Currently this driver is a USB driver.  It's not a conventional one in
 816  * the sense that it doesn't probe at the USB level.  Instead it waits to
 817  * be connected by HID through the hiddev_connect / hiddev_disconnect
 818  * routines.  The reason to register as a USB device is to gain part of the
 819  * minor number space from the USB major.
 820  *
 821  * In theory, should the HID code be generalized to more than one physical
 822  * medium (say, IEEE 1384), this driver will probably need to register its
 823  * own major number, and in doing so, no longer need to register with USB.
 824  * At that point the probe routine and hiddev_driver struct below will no
 825  * longer be useful.
 826  */
 827
 828
 829 /* We never attach in this manner, and rely on HID to connect us.  This
 830  * is why there is no disconnect routine defined in the usb_driver either.
 831  */
 832 static int hiddev_usbd_probe(struct usb_interface *intf,
 833                              const struct usb_device_id *hiddev_info)
 834 {
 835         return -ENODEV;
 836 }
 837
 838
 839 static /* const */ struct usb_driver hiddev_driver = {
 840         .owner =        THIS_MODULE,
 841         .name =         "hiddev",
 842         .probe =        hiddev_usbd_probe,
 843 };
 844
 845 int __init hiddev_init(void)
 846 {
 847         devfs_mk_dir("usb/hid");
 848         return usb_register(&hiddev_driver);
 849 }
 850
 851 void hiddev_exit(void)
 852 {
 853         usb_deregister(&hiddev_driver);
 854         devfs_remove("usb/hid");
 855 }