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      2048
  48
  49 struct hiddev {
  50         int exist;
  51         int open;
  52         struct mutex existancelock;
  53         wait_queue_head_t wait;
  54         struct hid_device *hid;
  55         struct list_head list;
  56         spinlock_t list_lock;
  57 };
  58
  59 struct hiddev_list {
  60         struct hiddev_usage_ref buffer[HIDDEV_BUFFER_SIZE];
  61         int head;
  62         int tail;
  63         unsigned flags;
  64         struct fasync_struct *fasync;
  65         struct hiddev *hiddev;
  66         struct list_head node;
  67         struct mutex thread_lock;
  68 };
  69
  70 static 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 int flags = rinfo->report_id & ~HID_REPORT_ID_MASK;
  82         unsigned int rid = rinfo->report_id & HID_REPORT_ID_MASK;
  83         struct hid_report_enum *report_enum;
  84         struct hid_report *report;
  85         struct list_head *list;
  86
  87         if (rinfo->report_type < HID_REPORT_TYPE_MIN ||
  88             rinfo->report_type > HID_REPORT_TYPE_MAX)
  89                 return NULL;
  90
  91         report_enum = hid->report_enum +
  92                 (rinfo->report_type - HID_REPORT_TYPE_MIN);
  93
  94         switch (flags) {
  95         case 0: /* Nothing to do -- report_id is already set correctly */
  96                 break;
  97
  98         case HID_REPORT_ID_FIRST:
  99                 if (list_empty(&report_enum->report_list))
 100                         return NULL;
 101
 102                 list = report_enum->report_list.next;
 103                 report = list_entry(list, struct hid_report, list);
 104                 rinfo->report_id = report->id;
 105                 break;
 106
 107         case HID_REPORT_ID_NEXT:
 108                 report = report_enum->report_id_hash[rid];
 109                 if (!report)
 110                         return NULL;
 111
 112                 list = report->list.next;
 113                 if (list == &report_enum->report_list)
 114                         return NULL;
 115
 116                 report = list_entry(list, struct hid_report, list);
 117                 rinfo->report_id = report->id;
 118                 break;
 119
 120         default:
 121                 return NULL;
 122         }
 123
 124         return report_enum->report_id_hash[rinfo->report_id];
 125 }
 126
 127 /*
 128  * Perform an exhaustive search of the report table for a usage, given its
 129  * type and usage id.
 130  */
 131 static struct hid_field *
 132 hiddev_lookup_usage(struct hid_device *hid, struct hiddev_usage_ref *uref)
 133 {
 134         int i, j;
 135         struct hid_report *report;
 136         struct hid_report_enum *report_enum;
 137         struct hid_field *field;
 138
 139         if (uref->report_type < HID_REPORT_TYPE_MIN ||
 140             uref->report_type > HID_REPORT_TYPE_MAX)
 141                 return NULL;
 142
 143         report_enum = hid->report_enum +
 144                 (uref->report_type - HID_REPORT_TYPE_MIN);
 145
 146         list_for_each_entry(report, &report_enum->report_list, list) {
 147                 for (i = 0; i < report->maxfield; i++) {
 148                         field = report->field[i];
 149                         for (j = 0; j < field->maxusage; j++) {
 150                                 if (field->usage[j].hid == uref->usage_code) {
 151                                         uref->report_id = report->id;
 152                                         uref->field_index = i;
 153                                         uref->usage_index = j;
 154                                         return field;
 155                                 }
 156                         }
 157                 }
 158         }
 159
 160         return NULL;
 161 }
 162
 163 static void hiddev_send_event(struct hid_device *hid,
 164                               struct hiddev_usage_ref *uref)
 165 {
 166         struct hiddev *hiddev = hid->hiddev;
 167         struct hiddev_list *list;
 168         unsigned long flags;
 169
 170         spin_lock_irqsave(&hiddev->list_lock, flags);
 171         list_for_each_entry(list, &hiddev->list, node) {
 172                 if (uref->field_index != HID_FIELD_INDEX_NONE ||
 173                     (list->flags & HIDDEV_FLAG_REPORT) != 0) {
 174                         list->buffer[list->head] = *uref;
 175                         list->head = (list->head + 1) &
 176                                 (HIDDEV_BUFFER_SIZE - 1);
 177                         kill_fasync(&list->fasync, SIGIO, POLL_IN);
 178                 }
 179         }
 180         spin_unlock_irqrestore(&hiddev->list_lock, flags);
 181
 182         wake_up_interruptible(&hiddev->wait);
 183 }
 184
 185 /*
 186  * This is where hid.c calls into hiddev to pass an event that occurred over
 187  * the interrupt pipe
 188  */
 189 void hiddev_hid_event(struct hid_device *hid, struct hid_field *field,
 190                       struct hid_usage *usage, __s32 value)
 191 {
 192         unsigned type = field->report_type;
 193         struct hiddev_usage_ref uref;
 194
 195         uref.report_type =
 196           (type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
 197           ((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
 198            ((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE : 0));
 199         uref.report_id = field->report->id;
 200         uref.field_index = field->index;
 201         uref.usage_index = (usage - field->usage);
 202         uref.usage_code = usage->hid;
 203         uref.value = value;
 204
 205         hiddev_send_event(hid, &uref);
 206 }
 207 EXPORT_SYMBOL_GPL(hiddev_hid_event);
 208
 209 void hiddev_report_event(struct hid_device *hid, struct hid_report *report)
 210 {
 211         unsigned type = report->type;
 212         struct hiddev_usage_ref uref;
 213
 214         memset(&uref, 0, sizeof(uref));
 215         uref.report_type =
 216           (type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
 217           ((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
 218            ((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE : 0));
 219         uref.report_id = report->id;
 220         uref.field_index = HID_FIELD_INDEX_NONE;
 221
 222         hiddev_send_event(hid, &uref);
 223 }
 224
 225 /*
 226  * fasync file op
 227  */
 228 static int hiddev_fasync(int fd, struct file *file, int on)
 229 {
 230         struct hiddev_list *list = file->private_data;
 231
 232         return fasync_helper(fd, file, on, &list->fasync);
 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         spin_lock_irqsave(&list->hiddev->list_lock, flags);
 245         list_del(&list->node);
 246         spin_unlock_irqrestore(&list->hiddev->list_lock, flags);
 247
 248         if (!--list->hiddev->open) {
 249                 if (list->hiddev->exist) {
 250                         usbhid_close(list->hiddev->hid);
 251                         usbhid_put_power(list->hiddev->hid);
 252                 } else {
 253                         kfree(list->hiddev);
 254                 }
 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         struct usb_interface *intf;
 269         struct hid_device *hid;
 270         struct hiddev *hiddev;
 271         int res;
 272
 273         intf = usbhid_find_interface(iminor(inode));
 274         if (!intf)
 275                 return -ENODEV;
 276         hid = usb_get_intfdata(intf);
 277         hiddev = hid->hiddev;
 278
 279         if (!(list = kzalloc(sizeof(struct hiddev_list), GFP_KERNEL)))
 280                 return -ENOMEM;
 281         mutex_init(&list->thread_lock);
 282         list->hiddev = hiddev;
 283         file->private_data = list;
 284
 285         /*
 286          * no need for locking because the USB major number
 287          * is shared which usbcore guards against disconnect
 288          */
 289         if (list->hiddev->exist) {
 290                 if (!list->hiddev->open++) {
 291                         res = usbhid_open(hiddev->hid);
 292                         if (res < 0) {
 293                                 res = -EIO;
 294                                 goto bail;
 295                         }
 296                 }
 297         } else {
 298                 res = -ENODEV;
 299                 goto bail;
 300         }
 301
 302         spin_lock_irq(&list->hiddev->list_lock);
 303         list_add_tail(&list->node, &hiddev->list);
 304         spin_unlock_irq(&list->hiddev->list_lock);
 305
 306         if (!list->hiddev->open++)
 307                 if (list->hiddev->exist) {
 308                         struct hid_device *hid = hiddev->hid;
 309                         res = usbhid_get_power(hid);
 310                         if (res < 0) {
 311                                 res = -EIO;
 312                                 goto bail;
 313                         }
 314                         usbhid_open(hid);
 315                 }
 316         return 0;
 317 bail:
 318         file->private_data = NULL;
 319         kfree(list);
 320         return res;
 321 }
 322
 323 /*
 324  * "write" file op
 325  */
 326 static ssize_t hiddev_write(struct file * file, const char __user * buffer, size_t count, loff_t *ppos)
 327 {
 328         return -EINVAL;
 329 }
 330
 331 /*
 332  * "read" file op
 333  */
 334 static ssize_t hiddev_read(struct file * file, char __user * buffer, size_t count, loff_t *ppos)
 335 {
 336         DEFINE_WAIT(wait);
 337         struct hiddev_list *list = file->private_data;
 338         int event_size;
 339         int retval;
 340
 341         event_size = ((list->flags & HIDDEV_FLAG_UREF) != 0) ?
 342                 sizeof(struct hiddev_usage_ref) : sizeof(struct hiddev_event);
 343
 344         if (count < event_size)
 345                 return 0;
 346
 347         /* lock against other threads */
 348         retval = mutex_lock_interruptible(&list->thread_lock);
 349         if (retval)
 350                 return -ERESTARTSYS;
 351
 352         while (retval == 0) {
 353                 if (list->head == list->tail) {
 354                         prepare_to_wait(&list->hiddev->wait, &wait, TASK_INTERRUPTIBLE);
 355
 356                         while (list->head == list->tail) {
 357                                 if (file->f_flags & O_NONBLOCK) {
 358                                         retval = -EAGAIN;
 359                                         break;
 360                                 }
 361                                 if (signal_pending(current)) {
 362                                         retval = -ERESTARTSYS;
 363                                         break;
 364                                 }
 365                                 if (!list->hiddev->exist) {
 366                                         retval = -EIO;
 367                                         break;
 368                                 }
 369
 370                                 /* let O_NONBLOCK tasks run */
 371                                 mutex_unlock(&list->thread_lock);
 372                                 schedule();
 373                                 if (mutex_lock_interruptible(&list->thread_lock))
 374                                         return -EINTR;
 375                                 set_current_state(TASK_INTERRUPTIBLE);
 376                         }
 377                         finish_wait(&list->hiddev->wait, &wait);
 378
 379                 }
 380
 381                 if (retval) {
 382                         mutex_unlock(&list->thread_lock);
 383                         return retval;
 384                 }
 385
 386
 387                 while (list->head != list->tail &&
 388                        retval + event_size <= count) {
 389                         if ((list->flags & HIDDEV_FLAG_UREF) == 0) {
 390                                 if (list->buffer[list->tail].field_index != HID_FIELD_INDEX_NONE) {
 391                                         struct hiddev_event event;
 392
 393                                         event.hid = list->buffer[list->tail].usage_code;
 394                                         event.value = list->buffer[list->tail].value;
 395                                         if (copy_to_user(buffer + retval, &event, sizeof(struct hiddev_event))) {
 396                                                 mutex_unlock(&list->thread_lock);
 397                                                 return -EFAULT;
 398                                         }
 399                                         retval += sizeof(struct hiddev_event);
 400                                 }
 401                         } else {
 402                                 if (list->buffer[list->tail].field_index != HID_FIELD_INDEX_NONE ||
 403                                     (list->flags & HIDDEV_FLAG_REPORT) != 0) {
 404
 405                                         if (copy_to_user(buffer + retval, list->buffer + list->tail, sizeof(struct hiddev_usage_ref))) {
 406                                                 mutex_unlock(&list->thread_lock);
 407                                                 return -EFAULT;
 408                                         }
 409                                         retval += sizeof(struct hiddev_usage_ref);
 410                                 }
 411                         }
 412                         list->tail = (list->tail + 1) & (HIDDEV_BUFFER_SIZE - 1);
 413                 }
 414
 415         }
 416         mutex_unlock(&list->thread_lock);
 417
 418         return retval;
 419 }
 420
 421 /*
 422  * "poll" file op
 423  * No kernel lock - fine
 424  */
 425 static unsigned int hiddev_poll(struct file *file, poll_table *wait)
 426 {
 427         struct hiddev_list *list = file->private_data;
 428
 429         poll_wait(file, &list->hiddev->wait, wait);
 430         if (list->head != list->tail)
 431                 return POLLIN | POLLRDNORM;
 432         if (!list->hiddev->exist)
 433                 return POLLERR | POLLHUP;
 434         return 0;
 435 }
 436
 437 /*
 438  * "ioctl" file op
 439  */
 440 static noinline int hiddev_ioctl_usage(struct hiddev *hiddev, unsigned int cmd, void __user *user_arg)
 441 {
 442         struct hid_device *hid = hiddev->hid;
 443         struct hiddev_report_info rinfo;
 444         struct hiddev_usage_ref_multi *uref_multi = NULL;
 445         struct hiddev_usage_ref *uref;
 446         struct hid_report *report;
 447         struct hid_field *field;
 448         int i;
 449
 450         uref_multi = kmalloc(sizeof(struct hiddev_usage_ref_multi), GFP_KERNEL);
 451         if (!uref_multi)
 452                 return -ENOMEM;
 453         uref = &uref_multi->uref;
 454         if (cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) {
 455                 if (copy_from_user(uref_multi, user_arg,
 456                                    sizeof(*uref_multi)))
 457                         goto fault;
 458         } else {
 459                 if (copy_from_user(uref, user_arg, sizeof(*uref)))
 460                         goto fault;
 461         }
 462
 463         switch (cmd) {
 464         case HIDIOCGUCODE:
 465                 rinfo.report_type = uref->report_type;
 466                 rinfo.report_id = uref->report_id;
 467                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 468                         goto inval;
 469
 470                 if (uref->field_index >= report->maxfield)
 471                         goto inval;
 472
 473                 field = report->field[uref->field_index];
 474                 if (uref->usage_index >= field->maxusage)
 475                         goto inval;
 476
 477                 uref->usage_code = field->usage[uref->usage_index].hid;
 478
 479                 if (copy_to_user(user_arg, uref, sizeof(*uref)))
 480                         goto fault;
 481
 482                 goto goodreturn;
 483
 484         default:
 485                 if (cmd != HIDIOCGUSAGE &&
 486                     cmd != HIDIOCGUSAGES &&
 487                     uref->report_type == HID_REPORT_TYPE_INPUT)
 488                         goto inval;
 489
 490                 if (uref->report_id == HID_REPORT_ID_UNKNOWN) {
 491                         field = hiddev_lookup_usage(hid, uref);
 492                         if (field == NULL)
 493                                 goto inval;
 494                 } else {
 495                         rinfo.report_type = uref->report_type;
 496                         rinfo.report_id = uref->report_id;
 497                         if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 498                                 goto inval;
 499
 500                         if (uref->field_index >= report->maxfield)
 501                                 goto inval;
 502
 503                         field = report->field[uref->field_index];
 504
 505                         if (cmd == HIDIOCGCOLLECTIONINDEX) {
 506                                 if (uref->usage_index >= field->maxusage)
 507                                         goto inval;
 508                         } else if (uref->usage_index >= field->report_count)
 509                                 goto inval;
 510
 511                         else if ((cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) &&
 512                                  (uref_multi->num_values > HID_MAX_MULTI_USAGES ||
 513                                   uref->usage_index + uref_multi->num_values > field->report_count))
 514                                 goto inval;
 515                         }
 516
 517                 switch (cmd) {
 518                 case HIDIOCGUSAGE:
 519                         uref->value = field->value[uref->usage_index];
 520                         if (copy_to_user(user_arg, uref, sizeof(*uref)))
 521                                 goto fault;
 522                         goto goodreturn;
 523
 524                 case HIDIOCSUSAGE:
 525                         field->value[uref->usage_index] = uref->value;
 526                         goto goodreturn;
 527
 528                 case HIDIOCGCOLLECTIONINDEX:
 529                         i = field->usage[uref->usage_index].collection_index;
 530                         kfree(uref_multi);
 531                         return i;
 532                 case HIDIOCGUSAGES:
 533                         for (i = 0; i < uref_multi->num_values; i++)
 534                                 uref_multi->values[i] =
 535                                     field->value[uref->usage_index + i];
 536                         if (copy_to_user(user_arg, uref_multi,
 537                                          sizeof(*uref_multi)))
 538                                 goto fault;
 539                         goto goodreturn;
 540                 case HIDIOCSUSAGES:
 541                         for (i = 0; i < uref_multi->num_values; i++)
 542                                 field->value[uref->usage_index + i] =
 543                                     uref_multi->values[i];
 544                         goto goodreturn;
 545                 }
 546
 547 goodreturn:
 548                 kfree(uref_multi);
 549                 return 0;
 550 fault:
 551                 kfree(uref_multi);
 552                 return -EFAULT;
 553 inval:
 554                 kfree(uref_multi);
 555                 return -EINVAL;
 556         }
 557 }
 558
 559 static noinline int hiddev_ioctl_string(struct hiddev *hiddev, unsigned int cmd, void __user *user_arg)
 560 {
 561         struct hid_device *hid = hiddev->hid;
 562         struct usb_device *dev = hid_to_usb_dev(hid);
 563         int idx, len;
 564         char *buf;
 565
 566         if (get_user(idx, (int __user *)user_arg))
 567                 return -EFAULT;
 568
 569         if ((buf = kmalloc(HID_STRING_SIZE, GFP_KERNEL)) == NULL)
 570                 return -ENOMEM;
 571
 572         if ((len = usb_string(dev, idx, buf, HID_STRING_SIZE-1)) < 0) {
 573                 kfree(buf);
 574                 return -EINVAL;
 575         }
 576
 577         if (copy_to_user(user_arg+sizeof(int), buf, len+1)) {
 578                 kfree(buf);
 579                 return -EFAULT;
 580         }
 581
 582         kfree(buf);
 583
 584         return len;
 585 }
 586
 587 static long hiddev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 588 {
 589         struct hiddev_list *list = file->private_data;
 590         struct hiddev *hiddev = list->hiddev;
 591         struct hid_device *hid = hiddev->hid;
 592         struct usb_device *dev;
 593         struct hiddev_collection_info cinfo;
 594         struct hiddev_report_info rinfo;
 595         struct hiddev_field_info finfo;
 596         struct hiddev_devinfo dinfo;
 597         struct hid_report *report;
 598         struct hid_field *field;
 599         struct usbhid_device *usbhid = hid->driver_data;
 600         void __user *user_arg = (void __user *)arg;
 601         int i, r;
 602
 603         /* Called without BKL by compat methods so no BKL taken */
 604
 605         /* FIXME: Who or what stop this racing with a disconnect ?? */
 606         if (!hiddev->exist || !hid)
 607                 return -EIO;
 608
 609         dev = hid_to_usb_dev(hid);
 610
 611         switch (cmd) {
 612
 613         case HIDIOCGVERSION:
 614                 return put_user(HID_VERSION, (int __user *)arg);
 615
 616         case HIDIOCAPPLICATION:
 617                 if (arg < 0 || arg >= hid->maxapplication)
 618                         return -EINVAL;
 619
 620                 for (i = 0; i < hid->maxcollection; i++)
 621                         if (hid->collection[i].type ==
 622                             HID_COLLECTION_APPLICATION && arg-- == 0)
 623                                 break;
 624
 625                 if (i == hid->maxcollection)
 626                         return -EINVAL;
 627
 628                 return hid->collection[i].usage;
 629
 630         case HIDIOCGDEVINFO:
 631                 dinfo.bustype = BUS_USB;
 632                 dinfo.busnum = dev->bus->busnum;
 633                 dinfo.devnum = dev->devnum;
 634                 dinfo.ifnum = usbhid->ifnum;
 635                 dinfo.vendor = le16_to_cpu(dev->descriptor.idVendor);
 636                 dinfo.product = le16_to_cpu(dev->descriptor.idProduct);
 637                 dinfo.version = le16_to_cpu(dev->descriptor.bcdDevice);
 638                 dinfo.num_applications = hid->maxapplication;
 639                 if (copy_to_user(user_arg, &dinfo, sizeof(dinfo)))
 640                         return -EFAULT;
 641
 642                 return 0;
 643
 644         case HIDIOCGFLAG:
 645                 if (put_user(list->flags, (int __user *)arg))
 646                         return -EFAULT;
 647
 648                 return 0;
 649
 650         case HIDIOCSFLAG:
 651                 {
 652                         int newflags;
 653                         if (get_user(newflags, (int __user *)arg))
 654                                 return -EFAULT;
 655
 656                         if ((newflags & ~HIDDEV_FLAGS) != 0 ||
 657                             ((newflags & HIDDEV_FLAG_REPORT) != 0 &&
 658                              (newflags & HIDDEV_FLAG_UREF) == 0))
 659                                 return -EINVAL;
 660
 661                         list->flags = newflags;
 662
 663                         return 0;
 664                 }
 665
 666         case HIDIOCGSTRING:
 667                 mutex_lock(&hiddev->existancelock);
 668                 if (hiddev->exist)
 669                         r = hiddev_ioctl_string(hiddev, cmd, user_arg);
 670                 else
 671                         r = -ENODEV;
 672                 mutex_unlock(&hiddev->existancelock);
 673                 return r;
 674
 675         case HIDIOCINITREPORT:
 676                 mutex_lock(&hiddev->existancelock);
 677                 if (!hiddev->exist) {
 678                         mutex_unlock(&hiddev->existancelock);
 679                         return -ENODEV;
 680                 }
 681                 usbhid_init_reports(hid);
 682                 mutex_unlock(&hiddev->existancelock);
 683
 684                 return 0;
 685
 686         case HIDIOCGREPORT:
 687                 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
 688                         return -EFAULT;
 689
 690                 if (rinfo.report_type == HID_REPORT_TYPE_OUTPUT)
 691                         return -EINVAL;
 692
 693                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 694                         return -EINVAL;
 695
 696                 mutex_lock(&hiddev->existancelock);
 697                 if (hiddev->exist) {
 698                         usbhid_submit_report(hid, report, USB_DIR_IN);
 699                         usbhid_wait_io(hid);
 700                 }
 701                 mutex_unlock(&hiddev->existancelock);
 702
 703                 return 0;
 704
 705         case HIDIOCSREPORT:
 706                 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
 707                         return -EFAULT;
 708
 709                 if (rinfo.report_type == HID_REPORT_TYPE_INPUT)
 710                         return -EINVAL;
 711
 712                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 713                         return -EINVAL;
 714
 715                 mutex_lock(&hiddev->existancelock);
 716                 if (hiddev->exist) {
 717                         usbhid_submit_report(hid, report, USB_DIR_OUT);
 718                         usbhid_wait_io(hid);
 719                 }
 720                 mutex_unlock(&hiddev->existancelock);
 721
 722                 return 0;
 723
 724         case HIDIOCGREPORTINFO:
 725                 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
 726                         return -EFAULT;
 727
 728                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 729                         return -EINVAL;
 730
 731                 rinfo.num_fields = report->maxfield;
 732
 733                 if (copy_to_user(user_arg, &rinfo, sizeof(rinfo)))
 734                         return -EFAULT;
 735
 736                 return 0;
 737
 738         case HIDIOCGFIELDINFO:
 739                 if (copy_from_user(&finfo, user_arg, sizeof(finfo)))
 740                         return -EFAULT;
 741                 rinfo.report_type = finfo.report_type;
 742                 rinfo.report_id = finfo.report_id;
 743                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 744                         return -EINVAL;
 745
 746                 if (finfo.field_index >= report->maxfield)
 747                         return -EINVAL;
 748
 749                 field = report->field[finfo.field_index];
 750                 memset(&finfo, 0, sizeof(finfo));
 751                 finfo.report_type = rinfo.report_type;
 752                 finfo.report_id = rinfo.report_id;
 753                 finfo.field_index = field->report_count - 1;
 754                 finfo.maxusage = field->maxusage;
 755                 finfo.flags = field->flags;
 756                 finfo.physical = field->physical;
 757                 finfo.logical = field->logical;
 758                 finfo.application = field->application;
 759                 finfo.logical_minimum = field->logical_minimum;
 760                 finfo.logical_maximum = field->logical_maximum;
 761                 finfo.physical_minimum = field->physical_minimum;
 762                 finfo.physical_maximum = field->physical_maximum;
 763                 finfo.unit_exponent = field->unit_exponent;
 764                 finfo.unit = field->unit;
 765
 766                 if (copy_to_user(user_arg, &finfo, sizeof(finfo)))
 767                         return -EFAULT;
 768
 769                 return 0;
 770
 771         case HIDIOCGUCODE:
 772                 /* fall through */
 773         case HIDIOCGUSAGE:
 774         case HIDIOCSUSAGE:
 775         case HIDIOCGUSAGES:
 776         case HIDIOCSUSAGES:
 777         case HIDIOCGCOLLECTIONINDEX:
 778                 mutex_lock(&hiddev->existancelock);
 779                 if (hiddev->exist)
 780                         r = hiddev_ioctl_usage(hiddev, cmd, user_arg);
 781                 else
 782                         r = -ENODEV;
 783                 mutex_unlock(&hiddev->existancelock);
 784                 return r;
 785
 786         case HIDIOCGCOLLECTIONINFO:
 787                 if (copy_from_user(&cinfo, user_arg, sizeof(cinfo)))
 788                         return -EFAULT;
 789
 790                 if (cinfo.index >= hid->maxcollection)
 791                         return -EINVAL;
 792
 793                 cinfo.type = hid->collection[cinfo.index].type;
 794                 cinfo.usage = hid->collection[cinfo.index].usage;
 795                 cinfo.level = hid->collection[cinfo.index].level;
 796
 797                 if (copy_to_user(user_arg, &cinfo, sizeof(cinfo)))
 798                         return -EFAULT;
 799                 return 0;
 800
 801         default:
 802
 803                 if (_IOC_TYPE(cmd) != 'H' || _IOC_DIR(cmd) != _IOC_READ)
 804                         return -EINVAL;
 805
 806                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGNAME(0))) {
 807                         int len;
 808                         if (!hid->name)
 809                                 return 0;
 810                         len = strlen(hid->name) + 1;
 811                         if (len > _IOC_SIZE(cmd))
 812                                  len = _IOC_SIZE(cmd);
 813                         return copy_to_user(user_arg, hid->name, len) ?
 814                                 -EFAULT : len;
 815                 }
 816
 817                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGPHYS(0))) {
 818                         int len;
 819                         if (!hid->phys)
 820                                 return 0;
 821                         len = strlen(hid->phys) + 1;
 822                         if (len > _IOC_SIZE(cmd))
 823                                 len = _IOC_SIZE(cmd);
 824                         return copy_to_user(user_arg, hid->phys, len) ?
 825                                 -EFAULT : len;
 826                 }
 827         }
 828         return -EINVAL;
 829 }
 830
 831 #ifdef CONFIG_COMPAT
 832 static long hiddev_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 833 {
 834         return hiddev_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
 835 }
 836 #endif
 837
 838 static const struct file_operations hiddev_fops = {
 839         .owner =        THIS_MODULE,
 840         .read =         hiddev_read,
 841         .write =        hiddev_write,
 842         .poll =         hiddev_poll,
 843         .open =         hiddev_open,
 844         .release =      hiddev_release,
 845         .unlocked_ioctl =       hiddev_ioctl,
 846         .fasync =       hiddev_fasync,
 847 #ifdef CONFIG_COMPAT
 848         .compat_ioctl   = hiddev_compat_ioctl,
 849 #endif
 850 };
 851
 852 static char *hiddev_devnode(struct device *dev, mode_t *mode)
 853 {
 854         return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
 855 }
 856
 857 static struct usb_class_driver hiddev_class = {
 858         .name =         "hiddev%d",
 859         .devnode =      hiddev_devnode,
 860         .fops =         &hiddev_fops,
 861         .minor_base =   HIDDEV_MINOR_BASE,
 862 };
 863
 864 /*
 865  * This is where hid.c calls us to connect a hid device to the hiddev driver
 866  */
 867 int hiddev_connect(struct hid_device *hid, unsigned int force)
 868 {
 869         struct hiddev *hiddev;
 870         struct usbhid_device *usbhid = hid->driver_data;
 871         int retval;
 872
 873         if (!force) {
 874                 unsigned int i;
 875                 for (i = 0; i < hid->maxcollection; i++)
 876                         if (hid->collection[i].type ==
 877                             HID_COLLECTION_APPLICATION &&
 878                             !IS_INPUT_APPLICATION(hid->collection[i].usage))
 879                                 break;
 880
 881                 if (i == hid->maxcollection)
 882                         return -1;
 883         }
 884
 885         if (!(hiddev = kzalloc(sizeof(struct hiddev), GFP_KERNEL)))
 886                 return -1;
 887
 888         init_waitqueue_head(&hiddev->wait);
 889         INIT_LIST_HEAD(&hiddev->list);
 890         spin_lock_init(&hiddev->list_lock);
 891         mutex_init(&hiddev->existancelock);
 892         hid->hiddev = hiddev;
 893         hiddev->hid = hid;
 894         hiddev->exist = 1;
 895         retval = usb_register_dev(usbhid->intf, &hiddev_class);
 896         if (retval) {
 897                 err_hid("Not able to get a minor for this device.");
 898                 hid->hiddev = NULL;
 899                 kfree(hiddev);
 900                 return -1;
 901         }
 902         return 0;
 903 }
 904
 905 /*
 906  * This is where hid.c calls us to disconnect a hiddev device from the
 907  * corresponding hid device (usually because the usb device has disconnected)
 908  */
 909 static struct usb_class_driver hiddev_class;
 910 void hiddev_disconnect(struct hid_device *hid)
 911 {
 912         struct hiddev *hiddev = hid->hiddev;
 913         struct usbhid_device *usbhid = hid->driver_data;
 914
 915         mutex_lock(&hiddev->existancelock);
 916         hiddev->exist = 0;
 917         mutex_unlock(&hiddev->existancelock);
 918
 919         usb_deregister_dev(usbhid->intf, &hiddev_class);
 920
 921         if (hiddev->open) {
 922                 usbhid_close(hiddev->hid);
 923                 wake_up_interruptible(&hiddev->wait);
 924         } else {
 925                 kfree(hiddev);
 926         }
 927 }
 928
 929 /* Currently this driver is a USB driver.  It's not a conventional one in
 930  * the sense that it doesn't probe at the USB level.  Instead it waits to
 931  * be connected by HID through the hiddev_connect / hiddev_disconnect
 932  * routines.  The reason to register as a USB device is to gain part of the
 933  * minor number space from the USB major.
 934  *
 935  * In theory, should the HID code be generalized to more than one physical
 936  * medium (say, IEEE 1384), this driver will probably need to register its
 937  * own major number, and in doing so, no longer need to register with USB.
 938  * At that point the probe routine and hiddev_driver struct below will no
 939  * longer be useful.
 940  */
 941
 942
 943 /* We never attach in this manner, and rely on HID to connect us.  This
 944  * is why there is no disconnect routine defined in the usb_driver either.
 945  */
 946 static int hiddev_usbd_probe(struct usb_interface *intf,
 947                              const struct usb_device_id *hiddev_info)
 948 {
 949         return -ENODEV;
 950 }
 951
 952 static /* const */ struct usb_driver hiddev_driver = {
 953         .name =         "hiddev",
 954         .probe =        hiddev_usbd_probe,
 955 };
 956
 957 int __init hiddev_init(void)
 958 {
 959         return usb_register(&hiddev_driver);
 960 }
 961
 962 void hiddev_exit(void)
 963 {
 964         usb_deregister(&hiddev_driver);
 965 }