drivers/hid/usbhid/hiddev.c

   1 /*
   2  *  Copyright (c) 2001 Paul Stewart
   3  *  Copyright (c) 2001 Vojtech Pavlik
   4  *
   5  *  HID char devices, giving access to raw HID device events.
   6  *
   7  */
   8
   9 /*
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  23  *
  24  * Should you need to contact me, the author, you can do so either by
  25  * e-mail - mail your message to Paul Stewart <stewart@wetlogic.net>
  26  */
  27
  28 #include <linux/poll.h>
  29 #include <linux/slab.h>
  30 #include <linux/module.h>
  31 #include <linux/init.h>
  32 #include <linux/smp_lock.h>
  33 #include <linux/input.h>
  34 #include <linux/usb.h>
  35 #include <linux/hid.h>
  36 #include <linux/hiddev.h>
  37 #include <linux/compat.h>
  38 #include "usbhid.h"
  39
  40 #ifdef CONFIG_USB_DYNAMIC_MINORS
  41 #define HIDDEV_MINOR_BASE       0
  42 #define HIDDEV_MINORS           256
  43 #else
  44 #define HIDDEV_MINOR_BASE       96
  45 #define HIDDEV_MINORS           16
  46 #endif
  47 #define HIDDEV_BUFFER_SIZE      64
  48
  49 struct hiddev {
  50         int exist;
  51         int open;
  52         wait_queue_head_t wait;
  53         struct hid_device *hid;
  54         struct list_head list;
  55         spinlock_t list_lock;
  56 };
  57
  58 struct hiddev_list {
  59         struct hiddev_usage_ref buffer[HIDDEV_BUFFER_SIZE];
  60         int head;
  61         int tail;
  62         unsigned flags;
  63         struct fasync_struct *fasync;
  64         struct hiddev *hiddev;
  65         struct list_head node;
  66 };
  67
  68 static struct hiddev *hiddev_table[HIDDEV_MINORS];
  69
  70 /*
  71  * Find a report, given the report's type and ID.  The ID can be specified
  72  * indirectly by REPORT_ID_FIRST (which returns the first report of the given
  73  * type) or by (REPORT_ID_NEXT | old_id), which returns the next report of the
  74  * given type which follows old_id.
  75  */
  76 static struct hid_report *
  77 hiddev_lookup_report(struct hid_device *hid, struct hiddev_report_info *rinfo)
  78 {
  79         unsigned int flags = rinfo->report_id & ~HID_REPORT_ID_MASK;
  80         unsigned int rid = rinfo->report_id & HID_REPORT_ID_MASK;
  81         struct hid_report_enum *report_enum;
  82         struct hid_report *report;
  83         struct list_head *list;
  84
  85         if (rinfo->report_type < HID_REPORT_TYPE_MIN ||
  86             rinfo->report_type > HID_REPORT_TYPE_MAX)
  87                 return NULL;
  88
  89         report_enum = hid->report_enum +
  90                 (rinfo->report_type - HID_REPORT_TYPE_MIN);
  91
  92         switch (flags) {
  93         case 0: /* Nothing to do -- report_id is already set correctly */
  94                 break;
  95
  96         case HID_REPORT_ID_FIRST:
  97                 if (list_empty(&report_enum->report_list))
  98                         return NULL;
  99
 100                 list = report_enum->report_list.next;
 101                 report = list_entry(list, struct hid_report, list);
 102                 rinfo->report_id = report->id;
 103                 break;
 104
 105         case HID_REPORT_ID_NEXT:
 106                 report = report_enum->report_id_hash[rid];
 107                 if (!report)
 108                         return NULL;
 109
 110                 list = report->list.next;
 111                 if (list == &report_enum->report_list)
 112                         return NULL;
 113
 114                 report = list_entry(list, struct hid_report, list);
 115                 rinfo->report_id = report->id;
 116                 break;
 117
 118         default:
 119                 return NULL;
 120         }
 121
 122         return report_enum->report_id_hash[rinfo->report_id];
 123 }
 124
 125 /*
 126  * Perform an exhaustive search of the report table for a usage, given its
 127  * type and usage id.
 128  */
 129 static struct hid_field *
 130 hiddev_lookup_usage(struct hid_device *hid, struct hiddev_usage_ref *uref)
 131 {
 132         int i, j;
 133         struct hid_report *report;
 134         struct hid_report_enum *report_enum;
 135         struct hid_field *field;
 136
 137         if (uref->report_type < HID_REPORT_TYPE_MIN ||
 138             uref->report_type > HID_REPORT_TYPE_MAX)
 139                 return NULL;
 140
 141         report_enum = hid->report_enum +
 142                 (uref->report_type - HID_REPORT_TYPE_MIN);
 143
 144         list_for_each_entry(report, &report_enum->report_list, list) {
 145                 for (i = 0; i < report->maxfield; i++) {
 146                         field = report->field[i];
 147                         for (j = 0; j < field->maxusage; j++) {
 148                                 if (field->usage[j].hid == uref->usage_code) {
 149                                         uref->report_id = report->id;
 150                                         uref->field_index = i;
 151                                         uref->usage_index = j;
 152                                         return field;
 153                                 }
 154                         }
 155                 }
 156         }
 157
 158         return NULL;
 159 }
 160
 161 static void hiddev_send_event(struct hid_device *hid,
 162                               struct hiddev_usage_ref *uref)
 163 {
 164         struct hiddev *hiddev = hid->hiddev;
 165         struct hiddev_list *list;
 166         unsigned long flags;
 167
 168         spin_lock_irqsave(&hiddev->list_lock, flags);
 169         list_for_each_entry(list, &hiddev->list, node) {
 170                 if (uref->field_index != HID_FIELD_INDEX_NONE ||
 171                     (list->flags & HIDDEV_FLAG_REPORT) != 0) {
 172                         list->buffer[list->head] = *uref;
 173                         list->head = (list->head + 1) &
 174                                 (HIDDEV_BUFFER_SIZE - 1);
 175                         kill_fasync(&list->fasync, SIGIO, POLL_IN);
 176                 }
 177         }
 178         spin_unlock_irqrestore(&hiddev->list_lock, flags);
 179
 180         wake_up_interruptible(&hiddev->wait);
 181 }
 182
 183 /*
 184  * This is where hid.c calls into hiddev to pass an event that occurred over
 185  * the interrupt pipe
 186  */
 187 void hiddev_hid_event(struct hid_device *hid, struct hid_field *field,
 188                       struct hid_usage *usage, __s32 value)
 189 {
 190         unsigned type = field->report_type;
 191         struct hiddev_usage_ref uref;
 192
 193         uref.report_type =
 194           (type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
 195           ((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
 196            ((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE : 0));
 197         uref.report_id = field->report->id;
 198         uref.field_index = field->index;
 199         uref.usage_index = (usage - field->usage);
 200         uref.usage_code = usage->hid;
 201         uref.value = value;
 202
 203         hiddev_send_event(hid, &uref);
 204 }
 205 EXPORT_SYMBOL_GPL(hiddev_hid_event);
 206
 207 void hiddev_report_event(struct hid_device *hid, struct hid_report *report)
 208 {
 209         unsigned type = report->type;
 210         struct hiddev_usage_ref uref;
 211
 212         memset(&uref, 0, sizeof(uref));
 213         uref.report_type =
 214           (type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
 215           ((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
 216            ((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE : 0));
 217         uref.report_id = report->id;
 218         uref.field_index = HID_FIELD_INDEX_NONE;
 219
 220         hiddev_send_event(hid, &uref);
 221 }
 222
 223 /*
 224  * fasync file op
 225  */
 226 static int hiddev_fasync(int fd, struct file *file, int on)
 227 {
 228         int retval;
 229         struct hiddev_list *list = file->private_data;
 230
 231         retval = fasync_helper(fd, file, on, &list->fasync);
 232
 233         return retval < 0 ? retval : 0;
 234 }
 235
 236
 237 /*
 238  * release file op
 239  */
 240 static int hiddev_release(struct inode * inode, struct file * file)
 241 {
 242         struct hiddev_list *list = file->private_data;
 243         unsigned long flags;
 244
 245         spin_lock_irqsave(&list->hiddev->list_lock, flags);
 246         list_del(&list->node);
 247         spin_unlock_irqrestore(&list->hiddev->list_lock, flags);
 248
 249         if (!--list->hiddev->open) {
 250                 if (list->hiddev->exist)
 251                         usbhid_close(list->hiddev->hid);
 252                 else
 253                         kfree(list->hiddev);
 254         }
 255
 256         kfree(list);
 257
 258         return 0;
 259 }
 260
 261 /*
 262  * open file op
 263  */
 264 static int hiddev_open(struct inode *inode, struct file *file)
 265 {
 266         struct hiddev_list *list;
 267         unsigned long flags;
 268
 269         int i = iminor(inode) - HIDDEV_MINOR_BASE;
 270
 271         if (i >= HIDDEV_MINORS || !hiddev_table[i])
 272                 return -ENODEV;
 273
 274         if (!(list = kzalloc(sizeof(struct hiddev_list), GFP_KERNEL)))
 275                 return -ENOMEM;
 276
 277         list->hiddev = hiddev_table[i];
 278
 279         spin_lock_irqsave(&list->hiddev->list_lock, flags);
 280         list_add_tail(&list->node, &hiddev_table[i]->list);
 281         spin_unlock_irqrestore(&list->hiddev->list_lock, flags);
 282
 283         file->private_data = list;
 284
 285         if (!list->hiddev->open++)
 286                 if (list->hiddev->exist)
 287                         usbhid_open(hiddev_table[i]->hid);
 288
 289         return 0;
 290 }
 291
 292 /*
 293  * "write" file op
 294  */
 295 static ssize_t hiddev_write(struct file * file, const char __user * buffer, size_t count, loff_t *ppos)
 296 {
 297         return -EINVAL;
 298 }
 299
 300 /*
 301  * "read" file op
 302  */
 303 static ssize_t hiddev_read(struct file * file, char __user * buffer, size_t count, loff_t *ppos)
 304 {
 305         DECLARE_WAITQUEUE(wait, current);
 306         struct hiddev_list *list = file->private_data;
 307         int event_size;
 308         int retval = 0;
 309
 310         event_size = ((list->flags & HIDDEV_FLAG_UREF) != 0) ?
 311                 sizeof(struct hiddev_usage_ref) : sizeof(struct hiddev_event);
 312
 313         if (count < event_size)
 314                 return 0;
 315
 316         while (retval == 0) {
 317                 if (list->head == list->tail) {
 318                         add_wait_queue(&list->hiddev->wait, &wait);
 319                         set_current_state(TASK_INTERRUPTIBLE);
 320
 321                         while (list->head == list->tail) {
 322                                 if (file->f_flags & O_NONBLOCK) {
 323                                         retval = -EAGAIN;
 324                                         break;
 325                                 }
 326                                 if (signal_pending(current)) {
 327                                         retval = -ERESTARTSYS;
 328                                         break;
 329                                 }
 330                                 if (!list->hiddev->exist) {
 331                                         retval = -EIO;
 332                                         break;
 333                                 }
 334
 335                                 schedule();
 336                                 set_current_state(TASK_INTERRUPTIBLE);
 337                         }
 338
 339                         set_current_state(TASK_RUNNING);
 340                         remove_wait_queue(&list->hiddev->wait, &wait);
 341                 }
 342
 343                 if (retval)
 344                         return retval;
 345
 346
 347                 while (list->head != list->tail &&
 348                        retval + event_size <= count) {
 349                         if ((list->flags & HIDDEV_FLAG_UREF) == 0) {
 350                                 if (list->buffer[list->tail].field_index !=
 351                                     HID_FIELD_INDEX_NONE) {
 352                                         struct hiddev_event event;
 353                                         event.hid = list->buffer[list->tail].usage_code;
 354                                         event.value = list->buffer[list->tail].value;
 355                                         if (copy_to_user(buffer + retval, &event, sizeof(struct hiddev_event)))
 356                                                 return -EFAULT;
 357                                         retval += sizeof(struct hiddev_event);
 358                                 }
 359                         } else {
 360                                 if (list->buffer[list->tail].field_index != HID_FIELD_INDEX_NONE ||
 361                                     (list->flags & HIDDEV_FLAG_REPORT) != 0) {
 362                                         if (copy_to_user(buffer + retval, list->buffer + list->tail, sizeof(struct hiddev_usage_ref)))
 363                                                 return -EFAULT;
 364                                         retval += sizeof(struct hiddev_usage_ref);
 365                                 }
 366                         }
 367                         list->tail = (list->tail + 1) & (HIDDEV_BUFFER_SIZE - 1);
 368                 }
 369
 370         }
 371
 372         return retval;
 373 }
 374
 375 /*
 376  * "poll" file op
 377  * No kernel lock - fine
 378  */
 379 static unsigned int hiddev_poll(struct file *file, poll_table *wait)
 380 {
 381         struct hiddev_list *list = file->private_data;
 382
 383         poll_wait(file, &list->hiddev->wait, wait);
 384         if (list->head != list->tail)
 385                 return POLLIN | POLLRDNORM;
 386         if (!list->hiddev->exist)
 387                 return POLLERR | POLLHUP;
 388         return 0;
 389 }
 390
 391 /*
 392  * "ioctl" file op
 393  */
 394 static noinline int hiddev_ioctl_usage(struct hiddev *hiddev, unsigned int cmd, void __user *user_arg)
 395 {
 396         struct hid_device *hid = hiddev->hid;
 397         struct hiddev_report_info rinfo;
 398         struct hiddev_usage_ref_multi *uref_multi = NULL;
 399         struct hiddev_usage_ref *uref;
 400         struct hid_report *report;
 401         struct hid_field *field;
 402         int i;
 403
 404         uref_multi = kmalloc(sizeof(struct hiddev_usage_ref_multi), GFP_KERNEL);
 405         if (!uref_multi)
 406                 return -ENOMEM;
 407         lock_kernel();
 408         uref = &uref_multi->uref;
 409         if (cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) {
 410                 if (copy_from_user(uref_multi, user_arg,
 411                                    sizeof(*uref_multi)))
 412                         goto fault;
 413         } else {
 414                 if (copy_from_user(uref, user_arg, sizeof(*uref)))
 415                         goto fault;
 416         }
 417
 418         switch (cmd) {
 419         case HIDIOCGUCODE:
 420                 rinfo.report_type = uref->report_type;
 421                 rinfo.report_id = uref->report_id;
 422                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 423                         goto inval;
 424
 425                 if (uref->field_index >= report->maxfield)
 426                         goto inval;
 427
 428                 field = report->field[uref->field_index];
 429                 if (uref->usage_index >= field->maxusage)
 430                         goto inval;
 431
 432                 uref->usage_code = field->usage[uref->usage_index].hid;
 433
 434                 if (copy_to_user(user_arg, uref, sizeof(*uref)))
 435                         goto fault;
 436
 437                 goto goodreturn;
 438
 439         default:
 440                 if (cmd != HIDIOCGUSAGE &&
 441                     cmd != HIDIOCGUSAGES &&
 442                     uref->report_type == HID_REPORT_TYPE_INPUT)
 443                         goto inval;
 444
 445                 if (uref->report_id == HID_REPORT_ID_UNKNOWN) {
 446                         field = hiddev_lookup_usage(hid, uref);
 447                         if (field == NULL)
 448                                 goto inval;
 449                 } else {
 450                         rinfo.report_type = uref->report_type;
 451                         rinfo.report_id = uref->report_id;
 452                         if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 453                                 goto inval;
 454
 455                         if (uref->field_index >= report->maxfield)
 456                                 goto inval;
 457
 458                         field = report->field[uref->field_index];
 459
 460                         if (cmd == HIDIOCGCOLLECTIONINDEX) {
 461                                 if (uref->usage_index >= field->maxusage)
 462                                         goto inval;
 463                         } else if (uref->usage_index >= field->report_count)
 464                                 goto inval;
 465
 466                         else if ((cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) &&
 467                                  (uref_multi->num_values > HID_MAX_MULTI_USAGES ||
 468                                   uref->usage_index + uref_multi->num_values > field->report_count))
 469                                 goto inval;
 470                         }
 471
 472                 switch (cmd) {
 473                 case HIDIOCGUSAGE:
 474                         uref->value = field->value[uref->usage_index];
 475                         if (copy_to_user(user_arg, uref, sizeof(*uref)))
 476                                 goto fault;
 477                         goto goodreturn;
 478
 479                 case HIDIOCSUSAGE:
 480                         field->value[uref->usage_index] = uref->value;
 481                         goto goodreturn;
 482
 483                 case HIDIOCGCOLLECTIONINDEX:
 484                         kfree(uref_multi);
 485                         return field->usage[uref->usage_index].collection_index;
 486                 case HIDIOCGUSAGES:
 487                         for (i = 0; i < uref_multi->num_values; i++)
 488                                 uref_multi->values[i] =
 489                                     field->value[uref->usage_index + i];
 490                         if (copy_to_user(user_arg, uref_multi,
 491                                          sizeof(*uref_multi)))
 492                                 goto fault;
 493                         goto goodreturn;
 494                 case HIDIOCSUSAGES:
 495                         for (i = 0; i < uref_multi->num_values; i++)
 496                                 field->value[uref->usage_index + i] =
 497                                     uref_multi->values[i];
 498                         goto goodreturn;
 499                 }
 500
 501 goodreturn:
 502                 unlock_kernel();
 503                 kfree(uref_multi);
 504                 return 0;
 505 fault:
 506                 unlock_kernel();
 507                 kfree(uref_multi);
 508                 return -EFAULT;
 509 inval:
 510                 unlock_kernel();
 511                 kfree(uref_multi);
 512                 return -EINVAL;
 513         }
 514 }
 515
 516 static noinline int hiddev_ioctl_string(struct hiddev *hiddev, unsigned int cmd, void __user *user_arg)
 517 {
 518         struct hid_device *hid = hiddev->hid;
 519         struct usb_device *dev = hid_to_usb_dev(hid);
 520         int idx, len;
 521         char *buf;
 522
 523         if (get_user(idx, (int __user *)user_arg))
 524                 return -EFAULT;
 525
 526         if ((buf = kmalloc(HID_STRING_SIZE, GFP_KERNEL)) == NULL)
 527                 return -ENOMEM;
 528
 529         if ((len = usb_string(dev, idx, buf, HID_STRING_SIZE-1)) < 0) {
 530                 kfree(buf);
 531                 return -EINVAL;
 532         }
 533
 534         if (copy_to_user(user_arg+sizeof(int), buf, len+1)) {
 535                 kfree(buf);
 536                 return -EFAULT;
 537         }
 538
 539         kfree(buf);
 540
 541         return len;
 542 }
 543
 544 static long hiddev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 545 {
 546         struct hiddev_list *list = file->private_data;
 547         struct hiddev *hiddev = list->hiddev;
 548         struct hid_device *hid = hiddev->hid;
 549         struct usb_device *dev = hid_to_usb_dev(hid);
 550         struct hiddev_collection_info cinfo;
 551         struct hiddev_report_info rinfo;
 552         struct hiddev_field_info finfo;
 553         struct hiddev_devinfo dinfo;
 554         struct hid_report *report;
 555         struct hid_field *field;
 556         struct usbhid_device *usbhid = hid->driver_data;
 557         void __user *user_arg = (void __user *)arg;
 558         int i;
 559
 560         /* Called without BKL by compat methods so no BKL taken */
 561
 562         /* FIXME: Who or what stop this racing with a disconnect ?? */
 563         if (!hiddev->exist)
 564                 return -EIO;
 565
 566         switch (cmd) {
 567
 568         case HIDIOCGVERSION:
 569                 return put_user(HID_VERSION, (int __user *)arg);
 570
 571         case HIDIOCAPPLICATION:
 572                 if (arg < 0 || arg >= hid->maxapplication)
 573                         return -EINVAL;
 574
 575                 for (i = 0; i < hid->maxcollection; i++)
 576                         if (hid->collection[i].type ==
 577                             HID_COLLECTION_APPLICATION && arg-- == 0)
 578                                 break;
 579
 580                 if (i == hid->maxcollection)
 581                         return -EINVAL;
 582
 583                 return hid->collection[i].usage;
 584
 585         case HIDIOCGDEVINFO:
 586                 dinfo.bustype = BUS_USB;
 587                 dinfo.busnum = dev->bus->busnum;
 588                 dinfo.devnum = dev->devnum;
 589                 dinfo.ifnum = usbhid->ifnum;
 590                 dinfo.vendor = le16_to_cpu(dev->descriptor.idVendor);
 591                 dinfo.product = le16_to_cpu(dev->descriptor.idProduct);
 592                 dinfo.version = le16_to_cpu(dev->descriptor.bcdDevice);
 593                 dinfo.num_applications = hid->maxapplication;
 594                 if (copy_to_user(user_arg, &dinfo, sizeof(dinfo)))
 595                         return -EFAULT;
 596
 597                 return 0;
 598
 599         case HIDIOCGFLAG:
 600                 if (put_user(list->flags, (int __user *)arg))
 601                         return -EFAULT;
 602
 603                 return 0;
 604
 605         case HIDIOCSFLAG:
 606                 {
 607                         int newflags;
 608                         if (get_user(newflags, (int __user *)arg))
 609                                 return -EFAULT;
 610
 611                         if ((newflags & ~HIDDEV_FLAGS) != 0 ||
 612                             ((newflags & HIDDEV_FLAG_REPORT) != 0 &&
 613                              (newflags & HIDDEV_FLAG_UREF) == 0))
 614                                 return -EINVAL;
 615
 616                         list->flags = newflags;
 617
 618                         return 0;
 619                 }
 620
 621         case HIDIOCGSTRING:
 622                 return hiddev_ioctl_string(hiddev, cmd, user_arg);
 623
 624         case HIDIOCINITREPORT:
 625                 usbhid_init_reports(hid);
 626
 627                 return 0;
 628
 629         case HIDIOCGREPORT:
 630                 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
 631                         return -EFAULT;
 632
 633                 if (rinfo.report_type == HID_REPORT_TYPE_OUTPUT)
 634                         return -EINVAL;
 635
 636                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 637                         return -EINVAL;
 638
 639                 usbhid_submit_report(hid, report, USB_DIR_IN);
 640                 usbhid_wait_io(hid);
 641
 642                 return 0;
 643
 644         case HIDIOCSREPORT:
 645                 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
 646                         return -EFAULT;
 647
 648                 if (rinfo.report_type == HID_REPORT_TYPE_INPUT)
 649                         return -EINVAL;
 650
 651                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 652                         return -EINVAL;
 653
 654                 usbhid_submit_report(hid, report, USB_DIR_OUT);
 655                 usbhid_wait_io(hid);
 656
 657                 return 0;
 658
 659         case HIDIOCGREPORTINFO:
 660                 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
 661                         return -EFAULT;
 662
 663                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 664                         return -EINVAL;
 665
 666                 rinfo.num_fields = report->maxfield;
 667
 668                 if (copy_to_user(user_arg, &rinfo, sizeof(rinfo)))
 669                         return -EFAULT;
 670
 671                 return 0;
 672
 673         case HIDIOCGFIELDINFO:
 674                 if (copy_from_user(&finfo, user_arg, sizeof(finfo)))
 675                         return -EFAULT;
 676                 rinfo.report_type = finfo.report_type;
 677                 rinfo.report_id = finfo.report_id;
 678                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 679                         return -EINVAL;
 680
 681                 if (finfo.field_index >= report->maxfield)
 682                         return -EINVAL;
 683
 684                 field = report->field[finfo.field_index];
 685                 memset(&finfo, 0, sizeof(finfo));
 686                 finfo.report_type = rinfo.report_type;
 687                 finfo.report_id = rinfo.report_id;
 688                 finfo.field_index = field->report_count - 1;
 689                 finfo.maxusage = field->maxusage;
 690                 finfo.flags = field->flags;
 691                 finfo.physical = field->physical;
 692                 finfo.logical = field->logical;
 693                 finfo.application = field->application;
 694                 finfo.logical_minimum = field->logical_minimum;
 695                 finfo.logical_maximum = field->logical_maximum;
 696                 finfo.physical_minimum = field->physical_minimum;
 697                 finfo.physical_maximum = field->physical_maximum;
 698                 finfo.unit_exponent = field->unit_exponent;
 699                 finfo.unit = field->unit;
 700
 701                 if (copy_to_user(user_arg, &finfo, sizeof(finfo)))
 702                         return -EFAULT;
 703
 704                 return 0;
 705
 706         case HIDIOCGUCODE:
 707                 /* fall through */
 708         case HIDIOCGUSAGE:
 709         case HIDIOCSUSAGE:
 710         case HIDIOCGUSAGES:
 711         case HIDIOCSUSAGES:
 712         case HIDIOCGCOLLECTIONINDEX:
 713                 return hiddev_ioctl_usage(hiddev, cmd, user_arg);
 714
 715         case HIDIOCGCOLLECTIONINFO:
 716                 if (copy_from_user(&cinfo, user_arg, sizeof(cinfo)))
 717                         return -EFAULT;
 718
 719                 if (cinfo.index >= hid->maxcollection)
 720                         return -EINVAL;
 721
 722                 cinfo.type = hid->collection[cinfo.index].type;
 723                 cinfo.usage = hid->collection[cinfo.index].usage;
 724                 cinfo.level = hid->collection[cinfo.index].level;
 725
 726                 if (copy_to_user(user_arg, &cinfo, sizeof(cinfo)))
 727                         return -EFAULT;
 728                 return 0;
 729
 730         default:
 731
 732                 if (_IOC_TYPE(cmd) != 'H' || _IOC_DIR(cmd) != _IOC_READ)
 733                         return -EINVAL;
 734
 735                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGNAME(0))) {
 736                         int len;
 737                         if (!hid->name)
 738                                 return 0;
 739                         len = strlen(hid->name) + 1;
 740                         if (len > _IOC_SIZE(cmd))
 741                                  len = _IOC_SIZE(cmd);
 742                         return copy_to_user(user_arg, hid->name, len) ?
 743                                 -EFAULT : len;
 744                 }
 745
 746                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGPHYS(0))) {
 747                         int len;
 748                         if (!hid->phys)
 749                                 return 0;
 750                         len = strlen(hid->phys) + 1;
 751                         if (len > _IOC_SIZE(cmd))
 752                                 len = _IOC_SIZE(cmd);
 753                         return copy_to_user(user_arg, hid->phys, len) ?
 754                                 -EFAULT : len;
 755                 }
 756         }
 757         return -EINVAL;
 758 }
 759
 760 #ifdef CONFIG_COMPAT
 761 static long hiddev_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 762 {
 763         return hiddev_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
 764 }
 765 #endif
 766
 767 static const struct file_operations hiddev_fops = {
 768         .owner =        THIS_MODULE,
 769         .read =         hiddev_read,
 770         .write =        hiddev_write,
 771         .poll =         hiddev_poll,
 772         .open =         hiddev_open,
 773         .release =      hiddev_release,
 774         .unlocked_ioctl =       hiddev_ioctl,
 775         .fasync =       hiddev_fasync,
 776 #ifdef CONFIG_COMPAT
 777         .compat_ioctl   = hiddev_compat_ioctl,
 778 #endif
 779 };
 780
 781 static struct usb_class_driver hiddev_class = {
 782         .name =         "hiddev%d",
 783         .fops =         &hiddev_fops,
 784         .minor_base =   HIDDEV_MINOR_BASE,
 785 };
 786
 787 /*
 788  * This is where hid.c calls us to connect a hid device to the hiddev driver
 789  */
 790 int hiddev_connect(struct hid_device *hid, unsigned int force)
 791 {
 792         struct hiddev *hiddev;
 793         struct usbhid_device *usbhid = hid->driver_data;
 794         int retval;
 795
 796         if (!force) {
 797                 unsigned int i;
 798                 for (i = 0; i < hid->maxcollection; i++)
 799                         if (hid->collection[i].type ==
 800                             HID_COLLECTION_APPLICATION &&
 801                             !IS_INPUT_APPLICATION(hid->collection[i].usage))
 802                                 break;
 803
 804                 if (i == hid->maxcollection)
 805                         return -1;
 806         }
 807
 808         if (!(hiddev = kzalloc(sizeof(struct hiddev), GFP_KERNEL)))
 809                 return -1;
 810
 811         retval = usb_register_dev(usbhid->intf, &hiddev_class);
 812         if (retval) {
 813                 err_hid("Not able to get a minor for this device.");
 814                 kfree(hiddev);
 815                 return -1;
 816         }
 817
 818         init_waitqueue_head(&hiddev->wait);
 819         INIT_LIST_HEAD(&hiddev->list);
 820         spin_lock_init(&hiddev->list_lock);
 821         hiddev->hid = hid;
 822         hiddev->exist = 1;
 823
 824         hid->minor = usbhid->intf->minor;
 825         hid->hiddev = hiddev;
 826
 827         hiddev_table[usbhid->intf->minor - HIDDEV_MINOR_BASE] = hiddev;
 828
 829         return 0;
 830 }
 831
 832 /*
 833  * This is where hid.c calls us to disconnect a hiddev device from the
 834  * corresponding hid device (usually because the usb device has disconnected)
 835  */
 836 static struct usb_class_driver hiddev_class;
 837 void hiddev_disconnect(struct hid_device *hid)
 838 {
 839         struct hiddev *hiddev = hid->hiddev;
 840         struct usbhid_device *usbhid = hid->driver_data;
 841
 842         hiddev->exist = 0;
 843
 844         hiddev_table[hiddev->hid->minor - HIDDEV_MINOR_BASE] = NULL;
 845         usb_deregister_dev(usbhid->intf, &hiddev_class);
 846
 847         if (hiddev->open) {
 848                 usbhid_close(hiddev->hid);
 849                 wake_up_interruptible(&hiddev->wait);
 850         } else {
 851                 kfree(hiddev);
 852         }
 853 }
 854
 855 /* Currently this driver is a USB driver.  It's not a conventional one in
 856  * the sense that it doesn't probe at the USB level.  Instead it waits to
 857  * be connected by HID through the hiddev_connect / hiddev_disconnect
 858  * routines.  The reason to register as a USB device is to gain part of the
 859  * minor number space from the USB major.
 860  *
 861  * In theory, should the HID code be generalized to more than one physical
 862  * medium (say, IEEE 1384), this driver will probably need to register its
 863  * own major number, and in doing so, no longer need to register with USB.
 864  * At that point the probe routine and hiddev_driver struct below will no
 865  * longer be useful.
 866  */
 867
 868
 869 /* We never attach in this manner, and rely on HID to connect us.  This
 870  * is why there is no disconnect routine defined in the usb_driver either.
 871  */
 872 static int hiddev_usbd_probe(struct usb_interface *intf,
 873                              const struct usb_device_id *hiddev_info)
 874 {
 875         return -ENODEV;
 876 }
 877
 878
 879 static /* const */ struct usb_driver hiddev_driver = {
 880         .name =         "hiddev",
 881         .probe =        hiddev_usbd_probe,
 882 };
 883
 884 int __init hiddev_init(void)
 885 {
 886         return usb_register(&hiddev_driver);
 887 }
 888
 889 void hiddev_exit(void)
 890 {
 891         usb_deregister(&hiddev_driver);
 892 }