drivers/hid/usbhid/hiddev.c

   1 /*
   2  *  Copyright (c) 2001 Paul Stewart
   3  *  Copyright (c) 2001 Vojtech Pavlik
   4  *
   5  *  HID char devices, giving access to raw HID device events.
   6  *
   7  */
   8
   9 /*
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  23  *
  24  * Should you need to contact me, the author, you can do so either by
  25  * e-mail - mail your message to Paul Stewart <stewart@wetlogic.net>
  26  */
  27
  28 #include <linux/poll.h>
  29 #include <linux/slab.h>
  30 #include <linux/module.h>
  31 #include <linux/init.h>
  32 #include <linux/smp_lock.h>
  33 #include <linux/input.h>
  34 #include <linux/usb.h>
  35 #include <linux/hid.h>
  36 #include <linux/hiddev.h>
  37 #include <linux/compat.h>
  38 #include "usbhid.h"
  39
  40 #ifdef CONFIG_USB_DYNAMIC_MINORS
  41 #define HIDDEV_MINOR_BASE       0
  42 #define HIDDEV_MINORS           256
  43 #else
  44 #define HIDDEV_MINOR_BASE       96
  45 #define HIDDEV_MINORS           16
  46 #endif
  47 #define HIDDEV_BUFFER_SIZE      2048
  48
  49 struct hiddev {
  50         int exist;
  51         int open;
  52         struct mutex existancelock;
  53         wait_queue_head_t wait;
  54         struct hid_device *hid;
  55         struct list_head list;
  56         spinlock_t list_lock;
  57 };
  58
  59 struct hiddev_list {
  60         struct hiddev_usage_ref buffer[HIDDEV_BUFFER_SIZE];
  61         int head;
  62         int tail;
  63         unsigned flags;
  64         struct fasync_struct *fasync;
  65         struct hiddev *hiddev;
  66         struct list_head node;
  67         struct mutex thread_lock;
  68 };
  69
  70 static struct usb_driver hiddev_driver;
  71
  72 /*
  73  * Find a report, given the report's type and ID.  The ID can be specified
  74  * indirectly by REPORT_ID_FIRST (which returns the first report of the given
  75  * type) or by (REPORT_ID_NEXT | old_id), which returns the next report of the
  76  * given type which follows old_id.
  77  */
  78 static struct hid_report *
  79 hiddev_lookup_report(struct hid_device *hid, struct hiddev_report_info *rinfo)
  80 {
  81         unsigned int flags = rinfo->report_id & ~HID_REPORT_ID_MASK;
  82         unsigned int rid = rinfo->report_id & HID_REPORT_ID_MASK;
  83         struct hid_report_enum *report_enum;
  84         struct hid_report *report;
  85         struct list_head *list;
  86
  87         if (rinfo->report_type < HID_REPORT_TYPE_MIN ||
  88             rinfo->report_type > HID_REPORT_TYPE_MAX)
  89                 return NULL;
  90
  91         report_enum = hid->report_enum +
  92                 (rinfo->report_type - HID_REPORT_TYPE_MIN);
  93
  94         switch (flags) {
  95         case 0: /* Nothing to do -- report_id is already set correctly */
  96                 break;
  97
  98         case HID_REPORT_ID_FIRST:
  99                 if (list_empty(&report_enum->report_list))
 100                         return NULL;
 101
 102                 list = report_enum->report_list.next;
 103                 report = list_entry(list, struct hid_report, list);
 104                 rinfo->report_id = report->id;
 105                 break;
 106
 107         case HID_REPORT_ID_NEXT:
 108                 report = report_enum->report_id_hash[rid];
 109                 if (!report)
 110                         return NULL;
 111
 112                 list = report->list.next;
 113                 if (list == &report_enum->report_list)
 114                         return NULL;
 115
 116                 report = list_entry(list, struct hid_report, list);
 117                 rinfo->report_id = report->id;
 118                 break;
 119
 120         default:
 121                 return NULL;
 122         }
 123
 124         return report_enum->report_id_hash[rinfo->report_id];
 125 }
 126
 127 /*
 128  * Perform an exhaustive search of the report table for a usage, given its
 129  * type and usage id.
 130  */
 131 static struct hid_field *
 132 hiddev_lookup_usage(struct hid_device *hid, struct hiddev_usage_ref *uref)
 133 {
 134         int i, j;
 135         struct hid_report *report;
 136         struct hid_report_enum *report_enum;
 137         struct hid_field *field;
 138
 139         if (uref->report_type < HID_REPORT_TYPE_MIN ||
 140             uref->report_type > HID_REPORT_TYPE_MAX)
 141                 return NULL;
 142
 143         report_enum = hid->report_enum +
 144                 (uref->report_type - HID_REPORT_TYPE_MIN);
 145
 146         list_for_each_entry(report, &report_enum->report_list, list) {
 147                 for (i = 0; i < report->maxfield; i++) {
 148                         field = report->field[i];
 149                         for (j = 0; j < field->maxusage; j++) {
 150                                 if (field->usage[j].hid == uref->usage_code) {
 151                                         uref->report_id = report->id;
 152                                         uref->field_index = i;
 153                                         uref->usage_index = j;
 154                                         return field;
 155                                 }
 156                         }
 157                 }
 158         }
 159
 160         return NULL;
 161 }
 162
 163 static void hiddev_send_event(struct hid_device *hid,
 164                               struct hiddev_usage_ref *uref)
 165 {
 166         struct hiddev *hiddev = hid->hiddev;
 167         struct hiddev_list *list;
 168         unsigned long flags;
 169
 170         spin_lock_irqsave(&hiddev->list_lock, flags);
 171         list_for_each_entry(list, &hiddev->list, node) {
 172                 if (uref->field_index != HID_FIELD_INDEX_NONE ||
 173                     (list->flags & HIDDEV_FLAG_REPORT) != 0) {
 174                         list->buffer[list->head] = *uref;
 175                         list->head = (list->head + 1) &
 176                                 (HIDDEV_BUFFER_SIZE - 1);
 177                         kill_fasync(&list->fasync, SIGIO, POLL_IN);
 178                 }
 179         }
 180         spin_unlock_irqrestore(&hiddev->list_lock, flags);
 181
 182         wake_up_interruptible(&hiddev->wait);
 183 }
 184
 185 /*
 186  * This is where hid.c calls into hiddev to pass an event that occurred over
 187  * the interrupt pipe
 188  */
 189 void hiddev_hid_event(struct hid_device *hid, struct hid_field *field,
 190                       struct hid_usage *usage, __s32 value)
 191 {
 192         unsigned type = field->report_type;
 193         struct hiddev_usage_ref uref;
 194
 195         uref.report_type =
 196           (type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
 197           ((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
 198            ((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE : 0));
 199         uref.report_id = field->report->id;
 200         uref.field_index = field->index;
 201         uref.usage_index = (usage - field->usage);
 202         uref.usage_code = usage->hid;
 203         uref.value = value;
 204
 205         hiddev_send_event(hid, &uref);
 206 }
 207 EXPORT_SYMBOL_GPL(hiddev_hid_event);
 208
 209 void hiddev_report_event(struct hid_device *hid, struct hid_report *report)
 210 {
 211         unsigned type = report->type;
 212         struct hiddev_usage_ref uref;
 213
 214         memset(&uref, 0, sizeof(uref));
 215         uref.report_type =
 216           (type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
 217           ((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
 218            ((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE : 0));
 219         uref.report_id = report->id;
 220         uref.field_index = HID_FIELD_INDEX_NONE;
 221
 222         hiddev_send_event(hid, &uref);
 223 }
 224
 225 /*
 226  * fasync file op
 227  */
 228 static int hiddev_fasync(int fd, struct file *file, int on)
 229 {
 230         struct hiddev_list *list = file->private_data;
 231
 232         return fasync_helper(fd, file, on, &list->fasync);
 233 }
 234
 235
 236 /*
 237  * release file op
 238  */
 239 static int hiddev_release(struct inode * inode, struct file * file)
 240 {
 241         struct hiddev_list *list = file->private_data;
 242         unsigned long flags;
 243
 244         spin_lock_irqsave(&list->hiddev->list_lock, flags);
 245         list_del(&list->node);
 246         spin_unlock_irqrestore(&list->hiddev->list_lock, flags);
 247
 248         if (!--list->hiddev->open) {
 249                 if (list->hiddev->exist) {
 250                         usbhid_close(list->hiddev->hid);
 251                         usbhid_put_power(list->hiddev->hid);
 252                 } else {
 253                         kfree(list->hiddev);
 254                 }
 255         }
 256
 257         kfree(list);
 258
 259         return 0;
 260 }
 261
 262 /*
 263  * open file op
 264  */
 265 static int hiddev_open(struct inode *inode, struct file *file)
 266 {
 267         struct hiddev_list *list;
 268         struct usb_interface *intf;
 269         struct hiddev *hiddev;
 270         int res;
 271
 272         intf = usb_find_interface(&hiddev_driver, iminor(inode));
 273         if (!intf)
 274                 return -ENODEV;
 275         hiddev = usb_get_intfdata(intf);
 276
 277         if (!(list = kzalloc(sizeof(struct hiddev_list), GFP_KERNEL)))
 278                 return -ENOMEM;
 279         mutex_init(&list->thread_lock);
 280         list->hiddev = hiddev;
 281         file->private_data = list;
 282
 283         /*
 284          * no need for locking because the USB major number
 285          * is shared which usbcore guards against disconnect
 286          */
 287         if (list->hiddev->exist) {
 288                 if (!list->hiddev->open++) {
 289                         res = usbhid_open(hiddev->hid);
 290                         if (res < 0) {
 291                                 res = -EIO;
 292                                 goto bail;
 293                         }
 294                 }
 295         } else {
 296                 res = -ENODEV;
 297                 goto bail;
 298         }
 299
 300         spin_lock_irq(&list->hiddev->list_lock);
 301         list_add_tail(&list->node, &hiddev->list);
 302         spin_unlock_irq(&list->hiddev->list_lock);
 303
 304         if (!list->hiddev->open++)
 305                 if (list->hiddev->exist) {
 306                         struct hid_device *hid = hiddev->hid;
 307                         res = usbhid_get_power(hid);
 308                         if (res < 0) {
 309                                 res = -EIO;
 310                                 goto bail;
 311                         }
 312                         usbhid_open(hid);
 313                 }
 314         return 0;
 315 bail:
 316         file->private_data = NULL;
 317         kfree(list);
 318         return res;
 319 }
 320
 321 /*
 322  * "write" file op
 323  */
 324 static ssize_t hiddev_write(struct file * file, const char __user * buffer, size_t count, loff_t *ppos)
 325 {
 326         return -EINVAL;
 327 }
 328
 329 /*
 330  * "read" file op
 331  */
 332 static ssize_t hiddev_read(struct file * file, char __user * buffer, size_t count, loff_t *ppos)
 333 {
 334         DEFINE_WAIT(wait);
 335         struct hiddev_list *list = file->private_data;
 336         int event_size;
 337         int retval;
 338
 339         event_size = ((list->flags & HIDDEV_FLAG_UREF) != 0) ?
 340                 sizeof(struct hiddev_usage_ref) : sizeof(struct hiddev_event);
 341
 342         if (count < event_size)
 343                 return 0;
 344
 345         /* lock against other threads */
 346         retval = mutex_lock_interruptible(&list->thread_lock);
 347         if (retval)
 348                 return -ERESTARTSYS;
 349
 350         while (retval == 0) {
 351                 if (list->head == list->tail) {
 352                         prepare_to_wait(&list->hiddev->wait, &wait, TASK_INTERRUPTIBLE);
 353
 354                         while (list->head == list->tail) {
 355                                 if (file->f_flags & O_NONBLOCK) {
 356                                         retval = -EAGAIN;
 357                                         break;
 358                                 }
 359                                 if (signal_pending(current)) {
 360                                         retval = -ERESTARTSYS;
 361                                         break;
 362                                 }
 363                                 if (!list->hiddev->exist) {
 364                                         retval = -EIO;
 365                                         break;
 366                                 }
 367
 368                                 /* let O_NONBLOCK tasks run */
 369                                 mutex_unlock(&list->thread_lock);
 370                                 schedule();
 371                                 if (mutex_lock_interruptible(&list->thread_lock))
 372                                         return -EINTR;
 373                                 set_current_state(TASK_INTERRUPTIBLE);
 374                         }
 375                         finish_wait(&list->hiddev->wait, &wait);
 376
 377                 }
 378
 379                 if (retval) {
 380                         mutex_unlock(&list->thread_lock);
 381                         return retval;
 382                 }
 383
 384
 385                 while (list->head != list->tail &&
 386                        retval + event_size <= count) {
 387                         if ((list->flags & HIDDEV_FLAG_UREF) == 0) {
 388                                 if (list->buffer[list->tail].field_index != HID_FIELD_INDEX_NONE) {
 389                                         struct hiddev_event event;
 390
 391                                         event.hid = list->buffer[list->tail].usage_code;
 392                                         event.value = list->buffer[list->tail].value;
 393                                         if (copy_to_user(buffer + retval, &event, sizeof(struct hiddev_event))) {
 394                                                 mutex_unlock(&list->thread_lock);
 395                                                 return -EFAULT;
 396                                         }
 397                                         retval += sizeof(struct hiddev_event);
 398                                 }
 399                         } else {
 400                                 if (list->buffer[list->tail].field_index != HID_FIELD_INDEX_NONE ||
 401                                     (list->flags & HIDDEV_FLAG_REPORT) != 0) {
 402
 403                                         if (copy_to_user(buffer + retval, list->buffer + list->tail, sizeof(struct hiddev_usage_ref))) {
 404                                                 mutex_unlock(&list->thread_lock);
 405                                                 return -EFAULT;
 406                                         }
 407                                         retval += sizeof(struct hiddev_usage_ref);
 408                                 }
 409                         }
 410                         list->tail = (list->tail + 1) & (HIDDEV_BUFFER_SIZE - 1);
 411                 }
 412
 413         }
 414         mutex_unlock(&list->thread_lock);
 415
 416         return retval;
 417 }
 418
 419 /*
 420  * "poll" file op
 421  * No kernel lock - fine
 422  */
 423 static unsigned int hiddev_poll(struct file *file, poll_table *wait)
 424 {
 425         struct hiddev_list *list = file->private_data;
 426
 427         poll_wait(file, &list->hiddev->wait, wait);
 428         if (list->head != list->tail)
 429                 return POLLIN | POLLRDNORM;
 430         if (!list->hiddev->exist)
 431                 return POLLERR | POLLHUP;
 432         return 0;
 433 }
 434
 435 /*
 436  * "ioctl" file op
 437  */
 438 static noinline int hiddev_ioctl_usage(struct hiddev *hiddev, unsigned int cmd, void __user *user_arg)
 439 {
 440         struct hid_device *hid = hiddev->hid;
 441         struct hiddev_report_info rinfo;
 442         struct hiddev_usage_ref_multi *uref_multi = NULL;
 443         struct hiddev_usage_ref *uref;
 444         struct hid_report *report;
 445         struct hid_field *field;
 446         int i;
 447
 448         uref_multi = kmalloc(sizeof(struct hiddev_usage_ref_multi), GFP_KERNEL);
 449         if (!uref_multi)
 450                 return -ENOMEM;
 451         uref = &uref_multi->uref;
 452         if (cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) {
 453                 if (copy_from_user(uref_multi, user_arg,
 454                                    sizeof(*uref_multi)))
 455                         goto fault;
 456         } else {
 457                 if (copy_from_user(uref, user_arg, sizeof(*uref)))
 458                         goto fault;
 459         }
 460
 461         switch (cmd) {
 462         case HIDIOCGUCODE:
 463                 rinfo.report_type = uref->report_type;
 464                 rinfo.report_id = uref->report_id;
 465                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 466                         goto inval;
 467
 468                 if (uref->field_index >= report->maxfield)
 469                         goto inval;
 470
 471                 field = report->field[uref->field_index];
 472                 if (uref->usage_index >= field->maxusage)
 473                         goto inval;
 474
 475                 uref->usage_code = field->usage[uref->usage_index].hid;
 476
 477                 if (copy_to_user(user_arg, uref, sizeof(*uref)))
 478                         goto fault;
 479
 480                 goto goodreturn;
 481
 482         default:
 483                 if (cmd != HIDIOCGUSAGE &&
 484                     cmd != HIDIOCGUSAGES &&
 485                     uref->report_type == HID_REPORT_TYPE_INPUT)
 486                         goto inval;
 487
 488                 if (uref->report_id == HID_REPORT_ID_UNKNOWN) {
 489                         field = hiddev_lookup_usage(hid, uref);
 490                         if (field == NULL)
 491                                 goto inval;
 492                 } else {
 493                         rinfo.report_type = uref->report_type;
 494                         rinfo.report_id = uref->report_id;
 495                         if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 496                                 goto inval;
 497
 498                         if (uref->field_index >= report->maxfield)
 499                                 goto inval;
 500
 501                         field = report->field[uref->field_index];
 502
 503                         if (cmd == HIDIOCGCOLLECTIONINDEX) {
 504                                 if (uref->usage_index >= field->maxusage)
 505                                         goto inval;
 506                         } else if (uref->usage_index >= field->report_count)
 507                                 goto inval;
 508
 509                         else if ((cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) &&
 510                                  (uref_multi->num_values > HID_MAX_MULTI_USAGES ||
 511                                   uref->usage_index + uref_multi->num_values > field->report_count))
 512                                 goto inval;
 513                         }
 514
 515                 switch (cmd) {
 516                 case HIDIOCGUSAGE:
 517                         uref->value = field->value[uref->usage_index];
 518                         if (copy_to_user(user_arg, uref, sizeof(*uref)))
 519                                 goto fault;
 520                         goto goodreturn;
 521
 522                 case HIDIOCSUSAGE:
 523                         field->value[uref->usage_index] = uref->value;
 524                         goto goodreturn;
 525
 526                 case HIDIOCGCOLLECTIONINDEX:
 527                         i = field->usage[uref->usage_index].collection_index;
 528                         kfree(uref_multi);
 529                         return i;
 530                 case HIDIOCGUSAGES:
 531                         for (i = 0; i < uref_multi->num_values; i++)
 532                                 uref_multi->values[i] =
 533                                     field->value[uref->usage_index + i];
 534                         if (copy_to_user(user_arg, uref_multi,
 535                                          sizeof(*uref_multi)))
 536                                 goto fault;
 537                         goto goodreturn;
 538                 case HIDIOCSUSAGES:
 539                         for (i = 0; i < uref_multi->num_values; i++)
 540                                 field->value[uref->usage_index + i] =
 541                                     uref_multi->values[i];
 542                         goto goodreturn;
 543                 }
 544
 545 goodreturn:
 546                 kfree(uref_multi);
 547                 return 0;
 548 fault:
 549                 kfree(uref_multi);
 550                 return -EFAULT;
 551 inval:
 552                 kfree(uref_multi);
 553                 return -EINVAL;
 554         }
 555 }
 556
 557 static noinline int hiddev_ioctl_string(struct hiddev *hiddev, unsigned int cmd, void __user *user_arg)
 558 {
 559         struct hid_device *hid = hiddev->hid;
 560         struct usb_device *dev = hid_to_usb_dev(hid);
 561         int idx, len;
 562         char *buf;
 563
 564         if (get_user(idx, (int __user *)user_arg))
 565                 return -EFAULT;
 566
 567         if ((buf = kmalloc(HID_STRING_SIZE, GFP_KERNEL)) == NULL)
 568                 return -ENOMEM;
 569
 570         if ((len = usb_string(dev, idx, buf, HID_STRING_SIZE-1)) < 0) {
 571                 kfree(buf);
 572                 return -EINVAL;
 573         }
 574
 575         if (copy_to_user(user_arg+sizeof(int), buf, len+1)) {
 576                 kfree(buf);
 577                 return -EFAULT;
 578         }
 579
 580         kfree(buf);
 581
 582         return len;
 583 }
 584
 585 static long hiddev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 586 {
 587         struct hiddev_list *list = file->private_data;
 588         struct hiddev *hiddev = list->hiddev;
 589         struct hid_device *hid = hiddev->hid;
 590         struct usb_device *dev;
 591         struct hiddev_collection_info cinfo;
 592         struct hiddev_report_info rinfo;
 593         struct hiddev_field_info finfo;
 594         struct hiddev_devinfo dinfo;
 595         struct hid_report *report;
 596         struct hid_field *field;
 597         struct usbhid_device *usbhid = hid->driver_data;
 598         void __user *user_arg = (void __user *)arg;
 599         int i, r;
 600
 601         /* Called without BKL by compat methods so no BKL taken */
 602
 603         /* FIXME: Who or what stop this racing with a disconnect ?? */
 604         if (!hiddev->exist || !hid)
 605                 return -EIO;
 606
 607         dev = hid_to_usb_dev(hid);
 608
 609         switch (cmd) {
 610
 611         case HIDIOCGVERSION:
 612                 return put_user(HID_VERSION, (int __user *)arg);
 613
 614         case HIDIOCAPPLICATION:
 615                 if (arg < 0 || arg >= hid->maxapplication)
 616                         return -EINVAL;
 617
 618                 for (i = 0; i < hid->maxcollection; i++)
 619                         if (hid->collection[i].type ==
 620                             HID_COLLECTION_APPLICATION && arg-- == 0)
 621                                 break;
 622
 623                 if (i == hid->maxcollection)
 624                         return -EINVAL;
 625
 626                 return hid->collection[i].usage;
 627
 628         case HIDIOCGDEVINFO:
 629                 dinfo.bustype = BUS_USB;
 630                 dinfo.busnum = dev->bus->busnum;
 631                 dinfo.devnum = dev->devnum;
 632                 dinfo.ifnum = usbhid->ifnum;
 633                 dinfo.vendor = le16_to_cpu(dev->descriptor.idVendor);
 634                 dinfo.product = le16_to_cpu(dev->descriptor.idProduct);
 635                 dinfo.version = le16_to_cpu(dev->descriptor.bcdDevice);
 636                 dinfo.num_applications = hid->maxapplication;
 637                 if (copy_to_user(user_arg, &dinfo, sizeof(dinfo)))
 638                         return -EFAULT;
 639
 640                 return 0;
 641
 642         case HIDIOCGFLAG:
 643                 if (put_user(list->flags, (int __user *)arg))
 644                         return -EFAULT;
 645
 646                 return 0;
 647
 648         case HIDIOCSFLAG:
 649                 {
 650                         int newflags;
 651                         if (get_user(newflags, (int __user *)arg))
 652                                 return -EFAULT;
 653
 654                         if ((newflags & ~HIDDEV_FLAGS) != 0 ||
 655                             ((newflags & HIDDEV_FLAG_REPORT) != 0 &&
 656                              (newflags & HIDDEV_FLAG_UREF) == 0))
 657                                 return -EINVAL;
 658
 659                         list->flags = newflags;
 660
 661                         return 0;
 662                 }
 663
 664         case HIDIOCGSTRING:
 665                 mutex_lock(&hiddev->existancelock);
 666                 if (hiddev->exist)
 667                         r = hiddev_ioctl_string(hiddev, cmd, user_arg);
 668                 else
 669                         r = -ENODEV;
 670                 mutex_unlock(&hiddev->existancelock);
 671                 return r;
 672
 673         case HIDIOCINITREPORT:
 674                 mutex_lock(&hiddev->existancelock);
 675                 if (!hiddev->exist) {
 676                         mutex_unlock(&hiddev->existancelock);
 677                         return -ENODEV;
 678                 }
 679                 usbhid_init_reports(hid);
 680                 mutex_unlock(&hiddev->existancelock);
 681
 682                 return 0;
 683
 684         case HIDIOCGREPORT:
 685                 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
 686                         return -EFAULT;
 687
 688                 if (rinfo.report_type == HID_REPORT_TYPE_OUTPUT)
 689                         return -EINVAL;
 690
 691                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 692                         return -EINVAL;
 693
 694                 mutex_lock(&hiddev->existancelock);
 695                 if (hiddev->exist) {
 696                         usbhid_submit_report(hid, report, USB_DIR_IN);
 697                         usbhid_wait_io(hid);
 698                 }
 699                 mutex_unlock(&hiddev->existancelock);
 700
 701                 return 0;
 702
 703         case HIDIOCSREPORT:
 704                 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
 705                         return -EFAULT;
 706
 707                 if (rinfo.report_type == HID_REPORT_TYPE_INPUT)
 708                         return -EINVAL;
 709
 710                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 711                         return -EINVAL;
 712
 713                 mutex_lock(&hiddev->existancelock);
 714                 if (hiddev->exist) {
 715                         usbhid_submit_report(hid, report, USB_DIR_OUT);
 716                         usbhid_wait_io(hid);
 717                 }
 718                 mutex_unlock(&hiddev->existancelock);
 719
 720                 return 0;
 721
 722         case HIDIOCGREPORTINFO:
 723                 if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
 724                         return -EFAULT;
 725
 726                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 727                         return -EINVAL;
 728
 729                 rinfo.num_fields = report->maxfield;
 730
 731                 if (copy_to_user(user_arg, &rinfo, sizeof(rinfo)))
 732                         return -EFAULT;
 733
 734                 return 0;
 735
 736         case HIDIOCGFIELDINFO:
 737                 if (copy_from_user(&finfo, user_arg, sizeof(finfo)))
 738                         return -EFAULT;
 739                 rinfo.report_type = finfo.report_type;
 740                 rinfo.report_id = finfo.report_id;
 741                 if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
 742                         return -EINVAL;
 743
 744                 if (finfo.field_index >= report->maxfield)
 745                         return -EINVAL;
 746
 747                 field = report->field[finfo.field_index];
 748                 memset(&finfo, 0, sizeof(finfo));
 749                 finfo.report_type = rinfo.report_type;
 750                 finfo.report_id = rinfo.report_id;
 751                 finfo.field_index = field->report_count - 1;
 752                 finfo.maxusage = field->maxusage;
 753                 finfo.flags = field->flags;
 754                 finfo.physical = field->physical;
 755                 finfo.logical = field->logical;
 756                 finfo.application = field->application;
 757                 finfo.logical_minimum = field->logical_minimum;
 758                 finfo.logical_maximum = field->logical_maximum;
 759                 finfo.physical_minimum = field->physical_minimum;
 760                 finfo.physical_maximum = field->physical_maximum;
 761                 finfo.unit_exponent = field->unit_exponent;
 762                 finfo.unit = field->unit;
 763
 764                 if (copy_to_user(user_arg, &finfo, sizeof(finfo)))
 765                         return -EFAULT;
 766
 767                 return 0;
 768
 769         case HIDIOCGUCODE:
 770                 /* fall through */
 771         case HIDIOCGUSAGE:
 772         case HIDIOCSUSAGE:
 773         case HIDIOCGUSAGES:
 774         case HIDIOCSUSAGES:
 775         case HIDIOCGCOLLECTIONINDEX:
 776                 mutex_lock(&hiddev->existancelock);
 777                 if (hiddev->exist)
 778                         r = hiddev_ioctl_usage(hiddev, cmd, user_arg);
 779                 else
 780                         r = -ENODEV;
 781                 mutex_unlock(&hiddev->existancelock);
 782                 return r;
 783
 784         case HIDIOCGCOLLECTIONINFO:
 785                 if (copy_from_user(&cinfo, user_arg, sizeof(cinfo)))
 786                         return -EFAULT;
 787
 788                 if (cinfo.index >= hid->maxcollection)
 789                         return -EINVAL;
 790
 791                 cinfo.type = hid->collection[cinfo.index].type;
 792                 cinfo.usage = hid->collection[cinfo.index].usage;
 793                 cinfo.level = hid->collection[cinfo.index].level;
 794
 795                 if (copy_to_user(user_arg, &cinfo, sizeof(cinfo)))
 796                         return -EFAULT;
 797                 return 0;
 798
 799         default:
 800
 801                 if (_IOC_TYPE(cmd) != 'H' || _IOC_DIR(cmd) != _IOC_READ)
 802                         return -EINVAL;
 803
 804                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGNAME(0))) {
 805                         int len;
 806                         if (!hid->name)
 807                                 return 0;
 808                         len = strlen(hid->name) + 1;
 809                         if (len > _IOC_SIZE(cmd))
 810                                  len = _IOC_SIZE(cmd);
 811                         return copy_to_user(user_arg, hid->name, len) ?
 812                                 -EFAULT : len;
 813                 }
 814
 815                 if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGPHYS(0))) {
 816                         int len;
 817                         if (!hid->phys)
 818                                 return 0;
 819                         len = strlen(hid->phys) + 1;
 820                         if (len > _IOC_SIZE(cmd))
 821                                 len = _IOC_SIZE(cmd);
 822                         return copy_to_user(user_arg, hid->phys, len) ?
 823                                 -EFAULT : len;
 824                 }
 825         }
 826         return -EINVAL;
 827 }
 828
 829 #ifdef CONFIG_COMPAT
 830 static long hiddev_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 831 {
 832         return hiddev_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
 833 }
 834 #endif
 835
 836 static const struct file_operations hiddev_fops = {
 837         .owner =        THIS_MODULE,
 838         .read =         hiddev_read,
 839         .write =        hiddev_write,
 840         .poll =         hiddev_poll,
 841         .open =         hiddev_open,
 842         .release =      hiddev_release,
 843         .unlocked_ioctl =       hiddev_ioctl,
 844         .fasync =       hiddev_fasync,
 845 #ifdef CONFIG_COMPAT
 846         .compat_ioctl   = hiddev_compat_ioctl,
 847 #endif
 848 };
 849
 850 static char *hiddev_devnode(struct device *dev, mode_t *mode)
 851 {
 852         return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
 853 }
 854
 855 static struct usb_class_driver hiddev_class = {
 856         .name =         "hiddev%d",
 857         .devnode =      hiddev_devnode,
 858         .fops =         &hiddev_fops,
 859         .minor_base =   HIDDEV_MINOR_BASE,
 860 };
 861
 862 /*
 863  * This is where hid.c calls us to connect a hid device to the hiddev driver
 864  */
 865 int hiddev_connect(struct hid_device *hid, unsigned int force)
 866 {
 867         struct hiddev *hiddev;
 868         struct usbhid_device *usbhid = hid->driver_data;
 869         int retval;
 870
 871         if (!force) {
 872                 unsigned int i;
 873                 for (i = 0; i < hid->maxcollection; i++)
 874                         if (hid->collection[i].type ==
 875                             HID_COLLECTION_APPLICATION &&
 876                             !IS_INPUT_APPLICATION(hid->collection[i].usage))
 877                                 break;
 878
 879                 if (i == hid->maxcollection)
 880                         return -1;
 881         }
 882
 883         if (!(hiddev = kzalloc(sizeof(struct hiddev), GFP_KERNEL)))
 884                 return -1;
 885
 886         init_waitqueue_head(&hiddev->wait);
 887         INIT_LIST_HEAD(&hiddev->list);
 888         spin_lock_init(&hiddev->list_lock);
 889         mutex_init(&hiddev->existancelock);
 890         hid->hiddev = hiddev;
 891         hiddev->hid = hid;
 892         hiddev->exist = 1;
 893         usb_set_intfdata(usbhid->intf, usbhid);
 894         retval = usb_register_dev(usbhid->intf, &hiddev_class);
 895         if (retval) {
 896                 err_hid("Not able to get a minor for this device.");
 897                 hid->hiddev = NULL;
 898                 kfree(hiddev);
 899                 return -1;
 900         }
 901         return 0;
 902 }
 903
 904 /*
 905  * This is where hid.c calls us to disconnect a hiddev device from the
 906  * corresponding hid device (usually because the usb device has disconnected)
 907  */
 908 static struct usb_class_driver hiddev_class;
 909 void hiddev_disconnect(struct hid_device *hid)
 910 {
 911         struct hiddev *hiddev = hid->hiddev;
 912         struct usbhid_device *usbhid = hid->driver_data;
 913
 914         mutex_lock(&hiddev->existancelock);
 915         hiddev->exist = 0;
 916         mutex_unlock(&hiddev->existancelock);
 917
 918         usb_deregister_dev(usbhid->intf, &hiddev_class);
 919
 920         if (hiddev->open) {
 921                 usbhid_close(hiddev->hid);
 922                 wake_up_interruptible(&hiddev->wait);
 923         } else {
 924                 kfree(hiddev);
 925         }
 926 }
 927
 928 /* Currently this driver is a USB driver.  It's not a conventional one in
 929  * the sense that it doesn't probe at the USB level.  Instead it waits to
 930  * be connected by HID through the hiddev_connect / hiddev_disconnect
 931  * routines.  The reason to register as a USB device is to gain part of the
 932  * minor number space from the USB major.
 933  *
 934  * In theory, should the HID code be generalized to more than one physical
 935  * medium (say, IEEE 1384), this driver will probably need to register its
 936  * own major number, and in doing so, no longer need to register with USB.
 937  * At that point the probe routine and hiddev_driver struct below will no
 938  * longer be useful.
 939  */
 940
 941
 942 /* We never attach in this manner, and rely on HID to connect us.  This
 943  * is why there is no disconnect routine defined in the usb_driver either.
 944  */
 945 static int hiddev_usbd_probe(struct usb_interface *intf,
 946                              const struct usb_device_id *hiddev_info)
 947 {
 948         return -ENODEV;
 949 }
 950
 951 static /* const */ struct usb_driver hiddev_driver = {
 952         .name =         "hiddev",
 953         .probe =        hiddev_usbd_probe,
 954 };
 955
 956 int __init hiddev_init(void)
 957 {
 958         return usb_register(&hiddev_driver);
 959 }
 960
 961 void hiddev_exit(void)
 962 {
 963         usb_deregister(&hiddev_driver);
 964 }