drivers/hid/usbhid/hiddev.c

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