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 hiddev *hiddev_table[HIDDEV_MINORS];
  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         int res, i;
 269
 270         lock_kernel();
 271         i = iminor(inode) - HIDDEV_MINOR_BASE;
 272
 273         if (i >= HIDDEV_MINORS || i < 0 || !hiddev_table[i])
 274                 return -ENODEV;
 275
 276         if (!(list = kzalloc(sizeof(struct hiddev_list), GFP_KERNEL)))
 277                 return -ENOMEM;
 278         mutex_init(&list->thread_lock);
 279
 280         list->hiddev = hiddev_table[i];
 281
 282
 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_table[i]->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_table[i]->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_table[i]->hid;
 309                         res = usbhid_get_power(hid);
 310                         if (res < 0) {
 311                                 res = -EIO;
 312                                 goto bail;
 313                         }
 314                         usbhid_open(hid);
 315                 }
 316
 317         unlock_kernel();
 318         return 0;
 319 bail:
 320         file->private_data = NULL;
 321         kfree(list);
 322         unlock_kernel();
 323         return res;
 324 }
 325
 326 /*
 327  * "write" file op
 328  */
 329 static ssize_t hiddev_write(struct file * file, const char __user * buffer, size_t count, loff_t *ppos)
 330 {
 331         return -EINVAL;
 332 }
 333
 334 /*
 335  * "read" file op
 336  */
 337 static ssize_t hiddev_read(struct file * file, char __user * buffer, size_t count, loff_t *ppos)
 338 {
 339         DEFINE_WAIT(wait);
 340         struct hiddev_list *list = file->private_data;
 341         int event_size;
 342         int retval;
 343
 344         event_size = ((list->flags & HIDDEV_FLAG_UREF) != 0) ?
 345                 sizeof(struct hiddev_usage_ref) : sizeof(struct hiddev_event);
 346
 347         if (count < event_size)
 348                 return 0;
 349
 350         /* lock against other threads */
 351         retval = mutex_lock_interruptible(&list->thread_lock);
 352         if (retval)
 353                 return -ERESTARTSYS;
 354
 355         while (retval == 0) {
 356                 if (list->head == list->tail) {
 357                         prepare_to_wait(&list->hiddev->wait, &wait, TASK_INTERRUPTIBLE);
 358
 359                         while (list->head == list->tail) {
 360                                 if (file->f_flags & O_NONBLOCK) {
 361                                         retval = -EAGAIN;
 362                                         break;
 363                                 }
 364                                 if (signal_pending(current)) {
 365                                         retval = -ERESTARTSYS;
 366                                         break;
 367                                 }
 368                                 if (!list->hiddev->exist) {
 369                                         retval = -EIO;
 370                                         break;
 371                                 }
 372
 373                                 /* let O_NONBLOCK tasks run */
 374                                 mutex_unlock(&list->thread_lock);
 375                                 schedule();
 376                                 if (mutex_lock_interruptible(&list->thread_lock))
 377                                         return -EINTR;
 378                                 set_current_state(TASK_INTERRUPTIBLE);
 379                         }
 380                         finish_wait(&list->hiddev->wait, &wait);
 381
 382                 }
 383
 384                 if (retval) {
 385                         mutex_unlock(&list->thread_lock);
 386                         return retval;
 387                 }
 388
 389
 390                 while (list->head != list->tail &&
 391                        retval + event_size <= count) {
 392                         if ((list->flags & HIDDEV_FLAG_UREF) == 0) {
 393                                 if (list->buffer[list->tail].field_index != HID_FIELD_INDEX_NONE) {
 394                                         struct hiddev_event event;
 395
 396                                         event.hid = list->buffer[list->tail].usage_code;
 397                                         event.value = list->buffer[list->tail].value;
 398                                         if (copy_to_user(buffer + retval, &event, sizeof(struct hiddev_event))) {
 399                                                 mutex_unlock(&list->thread_lock);
 400                                                 return -EFAULT;
 401                                         }
 402                                         retval += sizeof(struct hiddev_event);
 403                                 }
 404                         } else {
 405                                 if (list->buffer[list->tail].field_index != HID_FIELD_INDEX_NONE ||
 406                                     (list->flags & HIDDEV_FLAG_REPORT) != 0) {
 407
 408                                         if (copy_to_user(buffer + retval, list->buffer + list->tail, sizeof(struct hiddev_usage_ref))) {
 409                                                 mutex_unlock(&list->thread_lock);
 410                                                 return -EFAULT;
 411                                         }
 412                                         retval += sizeof(struct hiddev_usage_ref);
 413                                 }
 414                         }
 415                         list->tail = (list->tail + 1) & (HIDDEV_BUFFER_SIZE - 1);
 416                 }
 417
 418         }
 419         mutex_unlock(&list->thread_lock);
 420
 421         return retval;
 422 }
 423
 424 /*
 425  * "poll" file op
 426  * No kernel lock - fine
 427  */
 428 static unsigned int hiddev_poll(struct file *file, poll_table *wait)
 429 {
 430         struct hiddev_list *list = file->private_data;
 431
 432         poll_wait(file, &list->hiddev->wait, wait);
 433         if (list->head != list->tail)
 434                 return POLLIN | POLLRDNORM;
 435         if (!list->hiddev->exist)
 436                 return POLLERR | POLLHUP;
 437         return 0;
 438 }
 439
 440 /*
 441  * "ioctl" file op
 442  */
 443 static noinline int hiddev_ioctl_usage(struct hiddev *hiddev, unsigned int cmd, void __user *user_arg)
 444 {
 445         struct hid_device *hid = hiddev->hid;
 446         struct hiddev_report_info rinfo;
 447         struct hiddev_usage_ref_multi *uref_multi = NULL;
 448         struct hiddev_usage_ref *uref;
 449         struct hid_report *report;
 450         struct hid_field *field;
 451         int i;
 452
 453         uref_multi = kmalloc(sizeof(struct hiddev_usage_ref_multi), GFP_KERNEL);
 454         if (!uref_multi)
 455                 return -ENOMEM;
 456         uref = &uref_multi->uref;
 457         if (cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) {
 458                 if (copy_from_user(uref_multi, user_arg,
 459                                    sizeof(*uref_multi)))
 460                         goto fault;
 461         } else {
 462                 if (copy_from_user(uref, user_arg, sizeof(*uref)))
 463                         goto fault;
 464         }
 465
 466         switch (cmd) {
 467         case HIDIOCGUCODE:
 468                 rinfo.report_type = uref->report_type;
 469                 rinfo.report_id = uref->report_id;
 470                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 471                         goto inval;
 472
 473                 if (uref->field_index >= report->maxfield)
 474                         goto inval;
 475
 476                 field = report->field[uref->field_index];
 477                 if (uref->usage_index >= field->maxusage)
 478                         goto inval;
 479
 480                 uref->usage_code = field->usage[uref->usage_index].hid;
 481
 482                 if (copy_to_user(user_arg, uref, sizeof(*uref)))
 483                         goto fault;
 484
 485                 goto goodreturn;
 486
 487         default:
 488                 if (cmd != HIDIOCGUSAGE &&
 489                     cmd != HIDIOCGUSAGES &&
 490                     uref->report_type == HID_REPORT_TYPE_INPUT)
 491                         goto inval;
 492
 493                 if (uref->report_id == HID_REPORT_ID_UNKNOWN) {
 494                         field = hiddev_lookup_usage(hid, uref);
 495                         if (field == NULL)
 496                                 goto inval;
 497                 } else {
 498                         rinfo.report_type = uref->report_type;
 499                         rinfo.report_id = uref->report_id;
 500                         if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 501                                 goto inval;
 502
 503                         if (uref->field_index >= report->maxfield)
 504                                 goto inval;
 505
 506                         field = report->field[uref->field_index];
 507
 508                         if (cmd == HIDIOCGCOLLECTIONINDEX) {
 509                                 if (uref->usage_index >= field->maxusage)
 510                                         goto inval;
 511                         } else if (uref->usage_index >= field->report_count)
 512                                 goto inval;
 513
 514                         else if ((cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) &&
 515                                  (uref_multi->num_values > HID_MAX_MULTI_USAGES ||
 516                                   uref->usage_index + uref_multi->num_values > field->report_count))
 517                                 goto inval;
 518                         }
 519
 520                 switch (cmd) {
 521                 case HIDIOCGUSAGE:
 522                         uref->value = field->value[uref->usage_index];
 523                         if (copy_to_user(user_arg, uref, sizeof(*uref)))
 524                                 goto fault;
 525                         goto goodreturn;
 526
 527                 case HIDIOCSUSAGE:
 528                         field->value[uref->usage_index] = uref->value;
 529                         goto goodreturn;
 530
 531                 case HIDIOCGCOLLECTIONINDEX:
 532                         i = field->usage[uref->usage_index].collection_index;
 533                         kfree(uref_multi);
 534                         return i;
 535                 case HIDIOCGUSAGES:
 536                         for (i = 0; i < uref_multi->num_values; i++)
 537                                 uref_multi->values[i] =
 538                                     field->value[uref->usage_index + i];
 539                         if (copy_to_user(user_arg, uref_multi,
 540                                          sizeof(*uref_multi)))
 541                                 goto fault;
 542                         goto goodreturn;
 543                 case HIDIOCSUSAGES:
 544                         for (i = 0; i < uref_multi->num_values; i++)
 545                                 field->value[uref->usage_index + i] =
 546                                     uref_multi->values[i];
 547                         goto goodreturn;
 548                 }
 549
 550 goodreturn:
 551                 kfree(uref_multi);
 552                 return 0;
 553 fault:
 554                 kfree(uref_multi);
 555                 return -EFAULT;
 556 inval:
 557                 kfree(uref_multi);
 558                 return -EINVAL;
 559         }
 560 }
 561
 562 static noinline int hiddev_ioctl_string(struct hiddev *hiddev, unsigned int cmd, void __user *user_arg)
 563 {
 564         struct hid_device *hid = hiddev->hid;
 565         struct usb_device *dev = hid_to_usb_dev(hid);
 566         int idx, len;
 567         char *buf;
 568
 569         if (get_user(idx, (int __user *)user_arg))
 570                 return -EFAULT;
 571
 572         if ((buf = kmalloc(HID_STRING_SIZE, GFP_KERNEL)) == NULL)
 573                 return -ENOMEM;
 574
 575         if ((len = usb_string(dev, idx, buf, HID_STRING_SIZE-1)) < 0) {
 576                 kfree(buf);
 577                 return -EINVAL;
 578         }
 579
 580         if (copy_to_user(user_arg+sizeof(int), buf, len+1)) {
 581                 kfree(buf);
 582                 return -EFAULT;
 583         }
 584
 585         kfree(buf);
 586
 587         return len;
 588 }
 589
 590 static long hiddev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 591 {
 592         struct hiddev_list *list = file->private_data;
 593         struct hiddev *hiddev = list->hiddev;
 594         struct hid_device *hid = hiddev->hid;
 595         struct usb_device *dev = hid_to_usb_dev(hid);
 596         struct hiddev_collection_info cinfo;
 597         struct hiddev_report_info rinfo;
 598         struct hiddev_field_info finfo;
 599         struct hiddev_devinfo dinfo;
 600         struct hid_report *report;
 601         struct hid_field *field;
 602         struct usbhid_device *usbhid = hid->driver_data;
 603         void __user *user_arg = (void __user *)arg;
 604         int i, r;
 605
 606         /* Called without BKL by compat methods so no BKL taken */
 607
 608         /* FIXME: Who or what stop this racing with a disconnect ?? */
 609         if (!hiddev->exist)
 610                 return -EIO;
 611
 612         switch (cmd) {
 613
 614         case HIDIOCGVERSION:
 615                 return put_user(HID_VERSION, (int __user *)arg);
 616
 617         case HIDIOCAPPLICATION:
 618                 if (arg < 0 || arg >= hid->maxapplication)
 619                         return -EINVAL;
 620
 621                 for (i = 0; i < hid->maxcollection; i++)
 622                         if (hid->collection[i].type ==
 623                             HID_COLLECTION_APPLICATION && arg-- == 0)
 624                                 break;
 625
 626                 if (i == hid->maxcollection)
 627                         return -EINVAL;
 628
 629                 return hid->collection[i].usage;
 630
 631         case HIDIOCGDEVINFO:
 632                 dinfo.bustype = BUS_USB;
 633                 dinfo.busnum = dev->bus->busnum;
 634                 dinfo.devnum = dev->devnum;
 635                 dinfo.ifnum = usbhid->ifnum;
 636                 dinfo.vendor = le16_to_cpu(dev->descriptor.idVendor);
 637                 dinfo.product = le16_to_cpu(dev->descriptor.idProduct);
 638                 dinfo.version = le16_to_cpu(dev->descriptor.bcdDevice);
 639                 dinfo.num_applications = hid->maxapplication;
 640                 if (copy_to_user(user_arg, &dinfo, sizeof(dinfo)))
 641                         return -EFAULT;
 642
 643                 return 0;
 644
 645         case HIDIOCGFLAG:
 646                 if (put_user(list->flags, (int __user *)arg))
 647                         return -EFAULT;
 648
 649                 return 0;
 650
 651         case HIDIOCSFLAG:
 652                 {
 653                         int newflags;
 654                         if (get_user(newflags, (int __user *)arg))
 655                                 return -EFAULT;
 656
 657                         if ((newflags & ~HIDDEV_FLAGS) != 0 ||
 658                             ((newflags & HIDDEV_FLAG_REPORT) != 0 &&
 659                              (newflags & HIDDEV_FLAG_UREF) == 0))
 660                                 return -EINVAL;
 661
 662                         list->flags = newflags;
 663
 664                         return 0;
 665                 }
 666
 667         case HIDIOCGSTRING:
 668                 mutex_lock(&hiddev->existancelock);
 669                 if (hiddev->exist)
 670                         r = hiddev_ioctl_string(hiddev, cmd, user_arg);
 671                 else
 672                         r = -ENODEV;
 673                 mutex_unlock(&hiddev->existancelock);
 674                 return r;
 675
 676         case HIDIOCINITREPORT:
 677                 mutex_lock(&hiddev->existancelock);
 678                 if (!hiddev->exist) {
 679                         mutex_unlock(&hiddev->existancelock);
 680                         return -ENODEV;
 681                 }
 682                 usbhid_init_reports(hid);
 683                 mutex_unlock(&hiddev->existancelock);
 684
 685                 return 0;
 686
 687         case HIDIOCGREPORT:
 688                 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
 689                         return -EFAULT;
 690
 691                 if (rinfo.report_type == HID_REPORT_TYPE_OUTPUT)
 692                         return -EINVAL;
 693
 694                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 695                         return -EINVAL;
 696
 697                 mutex_lock(&hiddev->existancelock);
 698                 if (hiddev->exist) {
 699                         usbhid_submit_report(hid, report, USB_DIR_IN);
 700                         usbhid_wait_io(hid);
 701                 }
 702                 mutex_unlock(&hiddev->existancelock);
 703
 704                 return 0;
 705
 706         case HIDIOCSREPORT:
 707                 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
 708                         return -EFAULT;
 709
 710                 if (rinfo.report_type == HID_REPORT_TYPE_INPUT)
 711                         return -EINVAL;
 712
 713                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 714                         return -EINVAL;
 715
 716                 mutex_lock(&hiddev->existancelock);
 717                 if (hiddev->exist) {
 718                         usbhid_submit_report(hid, report, USB_DIR_OUT);
 719                         usbhid_wait_io(hid);
 720                 }
 721                 mutex_unlock(&hiddev->existancelock);
 722
 723                 return 0;
 724
 725         case HIDIOCGREPORTINFO:
 726                 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
 727                         return -EFAULT;
 728
 729                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 730                         return -EINVAL;
 731
 732                 rinfo.num_fields = report->maxfield;
 733
 734                 if (copy_to_user(user_arg, &rinfo, sizeof(rinfo)))
 735                         return -EFAULT;
 736
 737                 return 0;
 738
 739         case HIDIOCGFIELDINFO:
 740                 if (copy_from_user(&finfo, user_arg, sizeof(finfo)))
 741                         return -EFAULT;
 742                 rinfo.report_type = finfo.report_type;
 743                 rinfo.report_id = finfo.report_id;
 744                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 745                         return -EINVAL;
 746
 747                 if (finfo.field_index >= report->maxfield)
 748                         return -EINVAL;
 749
 750                 field = report->field[finfo.field_index];
 751                 memset(&finfo, 0, sizeof(finfo));
 752                 finfo.report_type = rinfo.report_type;
 753                 finfo.report_id = rinfo.report_id;
 754                 finfo.field_index = field->report_count - 1;
 755                 finfo.maxusage = field->maxusage;
 756                 finfo.flags = field->flags;
 757                 finfo.physical = field->physical;
 758                 finfo.logical = field->logical;
 759                 finfo.application = field->application;
 760                 finfo.logical_minimum = field->logical_minimum;
 761                 finfo.logical_maximum = field->logical_maximum;
 762                 finfo.physical_minimum = field->physical_minimum;
 763                 finfo.physical_maximum = field->physical_maximum;
 764                 finfo.unit_exponent = field->unit_exponent;
 765                 finfo.unit = field->unit;
 766
 767                 if (copy_to_user(user_arg, &finfo, sizeof(finfo)))
 768                         return -EFAULT;
 769
 770                 return 0;
 771
 772         case HIDIOCGUCODE:
 773                 /* fall through */
 774         case HIDIOCGUSAGE:
 775         case HIDIOCSUSAGE:
 776         case HIDIOCGUSAGES:
 777         case HIDIOCSUSAGES:
 778         case HIDIOCGCOLLECTIONINDEX:
 779                 mutex_lock(&hiddev->existancelock);
 780                 if (hiddev->exist)
 781                         r = hiddev_ioctl_usage(hiddev, cmd, user_arg);
 782                 else
 783                         r = -ENODEV;
 784                 mutex_unlock(&hiddev->existancelock);
 785                 return r;
 786
 787         case HIDIOCGCOLLECTIONINFO:
 788                 if (copy_from_user(&cinfo, user_arg, sizeof(cinfo)))
 789                         return -EFAULT;
 790
 791                 if (cinfo.index >= hid->maxcollection)
 792                         return -EINVAL;
 793
 794                 cinfo.type = hid->collection[cinfo.index].type;
 795                 cinfo.usage = hid->collection[cinfo.index].usage;
 796                 cinfo.level = hid->collection[cinfo.index].level;
 797
 798                 if (copy_to_user(user_arg, &cinfo, sizeof(cinfo)))
 799                         return -EFAULT;
 800                 return 0;
 801
 802         default:
 803
 804                 if (_IOC_TYPE(cmd) != 'H' || _IOC_DIR(cmd) != _IOC_READ)
 805                         return -EINVAL;
 806
 807                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGNAME(0))) {
 808                         int len;
 809                         if (!hid->name)
 810                                 return 0;
 811                         len = strlen(hid->name) + 1;
 812                         if (len > _IOC_SIZE(cmd))
 813                                  len = _IOC_SIZE(cmd);
 814                         return copy_to_user(user_arg, hid->name, len) ?
 815                                 -EFAULT : len;
 816                 }
 817
 818                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGPHYS(0))) {
 819                         int len;
 820                         if (!hid->phys)
 821                                 return 0;
 822                         len = strlen(hid->phys) + 1;
 823                         if (len > _IOC_SIZE(cmd))
 824                                 len = _IOC_SIZE(cmd);
 825                         return copy_to_user(user_arg, hid->phys, len) ?
 826                                 -EFAULT : len;
 827                 }
 828         }
 829         return -EINVAL;
 830 }
 831
 832 #ifdef CONFIG_COMPAT
 833 static long hiddev_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 834 {
 835         return hiddev_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
 836 }
 837 #endif
 838
 839 static const struct file_operations hiddev_fops = {
 840         .owner =        THIS_MODULE,
 841         .read =         hiddev_read,
 842         .write =        hiddev_write,
 843         .poll =         hiddev_poll,
 844         .open =         hiddev_open,
 845         .release =      hiddev_release,
 846         .unlocked_ioctl =       hiddev_ioctl,
 847         .fasync =       hiddev_fasync,
 848 #ifdef CONFIG_COMPAT
 849         .compat_ioctl   = hiddev_compat_ioctl,
 850 #endif
 851 };
 852
 853 static char *hiddev_devnode(struct device *dev, mode_t *mode)
 854 {
 855         return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
 856 }
 857
 858 static struct usb_class_driver hiddev_class = {
 859         .name =         "hiddev%d",
 860         .devnode =      hiddev_devnode,
 861         .fops =         &hiddev_fops,
 862         .minor_base =   HIDDEV_MINOR_BASE,
 863 };
 864
 865 /*
 866  * This is where hid.c calls us to connect a hid device to the hiddev driver
 867  */
 868 int hiddev_connect(struct hid_device *hid, unsigned int force)
 869 {
 870         struct hiddev *hiddev;
 871         struct usbhid_device *usbhid = hid->driver_data;
 872         int retval;
 873
 874         if (!force) {
 875                 unsigned int i;
 876                 for (i = 0; i < hid->maxcollection; i++)
 877                         if (hid->collection[i].type ==
 878                             HID_COLLECTION_APPLICATION &&
 879                             !IS_INPUT_APPLICATION(hid->collection[i].usage))
 880                                 break;
 881
 882                 if (i == hid->maxcollection)
 883                         return -1;
 884         }
 885
 886         if (!(hiddev = kzalloc(sizeof(struct hiddev), GFP_KERNEL)))
 887                 return -1;
 888
 889         init_waitqueue_head(&hiddev->wait);
 890         INIT_LIST_HEAD(&hiddev->list);
 891         spin_lock_init(&hiddev->list_lock);
 892         mutex_init(&hiddev->existancelock);
 893         hid->hiddev = hiddev;
 894         hiddev->hid = hid;
 895         hiddev->exist = 1;
 896
 897         /* when lock_kernel() usage is fixed in usb_open(),
 898          * we could also fix it here */
 899         lock_kernel();
 900         retval = usb_register_dev(usbhid->intf, &hiddev_class);
 901         if (retval) {
 902                 err_hid("Not able to get a minor for this device.");
 903                 hid->hiddev = NULL;
 904                 unlock_kernel();
 905                 kfree(hiddev);
 906                 return -1;
 907         } else {
 908                 hid->minor = usbhid->intf->minor;
 909                 hiddev_table[usbhid->intf->minor - HIDDEV_MINOR_BASE] = hiddev;
 910         }
 911         unlock_kernel();
 912
 913         return 0;
 914 }
 915
 916 /*
 917  * This is where hid.c calls us to disconnect a hiddev device from the
 918  * corresponding hid device (usually because the usb device has disconnected)
 919  */
 920 static struct usb_class_driver hiddev_class;
 921 void hiddev_disconnect(struct hid_device *hid)
 922 {
 923         struct hiddev *hiddev = hid->hiddev;
 924         struct usbhid_device *usbhid = hid->driver_data;
 925
 926         mutex_lock(&hiddev->existancelock);
 927         hiddev->exist = 0;
 928         mutex_unlock(&hiddev->existancelock);
 929
 930         hiddev_table[hiddev->hid->minor - HIDDEV_MINOR_BASE] = NULL;
 931         usb_deregister_dev(usbhid->intf, &hiddev_class);
 932
 933         if (hiddev->open) {
 934                 usbhid_close(hiddev->hid);
 935                 wake_up_interruptible(&hiddev->wait);
 936         } else {
 937                 kfree(hiddev);
 938         }
 939 }
 940
 941 /* Currently this driver is a USB driver.  It's not a conventional one in
 942  * the sense that it doesn't probe at the USB level.  Instead it waits to
 943  * be connected by HID through the hiddev_connect / hiddev_disconnect
 944  * routines.  The reason to register as a USB device is to gain part of the
 945  * minor number space from the USB major.
 946  *
 947  * In theory, should the HID code be generalized to more than one physical
 948  * medium (say, IEEE 1384), this driver will probably need to register its
 949  * own major number, and in doing so, no longer need to register with USB.
 950  * At that point the probe routine and hiddev_driver struct below will no
 951  * longer be useful.
 952  */
 953
 954
 955 /* We never attach in this manner, and rely on HID to connect us.  This
 956  * is why there is no disconnect routine defined in the usb_driver either.
 957  */
 958 static int hiddev_usbd_probe(struct usb_interface *intf,
 959                              const struct usb_device_id *hiddev_info)
 960 {
 961         return -ENODEV;
 962 }
 963
 964 static /* const */ struct usb_driver hiddev_driver = {
 965         .name =         "hiddev",
 966         .probe =        hiddev_usbd_probe,
 967 };
 968
 969 int __init hiddev_init(void)
 970 {
 971         return usb_register(&hiddev_driver);
 972 }
 973
 974 void hiddev_exit(void)
 975 {
 976         usb_deregister(&hiddev_driver);
 977 }