drivers/input/input.c

   1 /*
   2  * The input core
   3  *
   4  * Copyright (c) 1999-2002 Vojtech Pavlik
   5  */
   6
   7 /*
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU General Public License version 2 as published by
  10  * the Free Software Foundation.
  11  */
  12
  13 #define pr_fmt(fmt) KBUILD_BASENAME ": " fmt
  14
  15 #include <linux/init.h>
  16 #include <linux/types.h>
  17 #include <linux/input/mt.h>
  18 #include <linux/module.h>
  19 #include <linux/slab.h>
  20 #include <linux/random.h>
  21 #include <linux/major.h>
  22 #include <linux/proc_fs.h>
  23 #include <linux/sched.h>
  24 #include <linux/seq_file.h>
  25 #include <linux/poll.h>
  26 #include <linux/device.h>
  27 #include <linux/mutex.h>
  28 #include <linux/rcupdate.h>
  29 #include "input-compat.h"
  30
  31 MODULE_AUTHOR("Vojtech Pavlik <vojtech@suse.cz>");
  32 MODULE_DESCRIPTION("Input core");
  33 MODULE_LICENSE("GPL");
  34
  35 #define INPUT_DEVICES   256
  36
  37 static LIST_HEAD(input_dev_list);
  38 static LIST_HEAD(input_handler_list);
  39
  40 /*
  41  * input_mutex protects access to both input_dev_list and input_handler_list.
  42  * This also causes input_[un]register_device and input_[un]register_handler
  43  * be mutually exclusive which simplifies locking in drivers implementing
  44  * input handlers.
  45  */
  46 static DEFINE_MUTEX(input_mutex);
  47
  48 static struct input_handler *input_table[8];
  49
  50 static inline int is_event_supported(unsigned int code,
  51                                      unsigned long *bm, unsigned int max)
  52 {
  53         return code <= max && test_bit(code, bm);
  54 }
  55
  56 static int input_defuzz_abs_event(int value, int old_val, int fuzz)
  57 {
  58         if (fuzz) {
  59                 if (value > old_val - fuzz / 2 && value < old_val + fuzz / 2)
  60                         return old_val;
  61
  62                 if (value > old_val - fuzz && value < old_val + fuzz)
  63                         return (old_val * 3 + value) / 4;
  64
  65                 if (value > old_val - fuzz * 2 && value < old_val + fuzz * 2)
  66                         return (old_val + value) / 2;
  67         }
  68
  69         return value;
  70 }
  71
  72 /*
  73  * Pass event first through all filters and then, if event has not been
  74  * filtered out, through all open handles. This function is called with
  75  * dev->event_lock held and interrupts disabled.
  76  */
  77 static void input_pass_event(struct input_dev *dev,
  78                              struct input_handler *src_handler,
  79                              unsigned int type, unsigned int code, int value)
  80 {
  81         struct input_handler *handler;
  82         struct input_handle *handle;
  83
  84         rcu_read_lock();
  85
  86         handle = rcu_dereference(dev->grab);
  87         if (handle)
  88                 handle->handler->event(handle, type, code, value);
  89         else {
  90                 bool filtered = false;
  91
  92                 list_for_each_entry_rcu(handle, &dev->h_list, d_node) {
  93                         if (!handle->open)
  94                                 continue;
  95
  96                         handler = handle->handler;
  97
  98                         /*
  99                          * If this is the handler that injected this
 100                          * particular event we want to skip it to avoid
 101                          * filters firing again and again.
 102                          */
 103                         if (handler == src_handler)
 104                                 continue;
 105
 106                         if (!handler->filter) {
 107                                 if (filtered)
 108                                         break;
 109
 110                                 handler->event(handle, type, code, value);
 111
 112                         } else if (handler->filter(handle, type, code, value))
 113                                 filtered = true;
 114                 }
 115         }
 116
 117         rcu_read_unlock();
 118 }
 119
 120 /*
 121  * Generate software autorepeat event. Note that we take
 122  * dev->event_lock here to avoid racing with input_event
 123  * which may cause keys get "stuck".
 124  */
 125 static void input_repeat_key(unsigned long data)
 126 {
 127         struct input_dev *dev = (void *) data;
 128         unsigned long flags;
 129
 130         spin_lock_irqsave(&dev->event_lock, flags);
 131
 132         if (test_bit(dev->repeat_key, dev->key) &&
 133             is_event_supported(dev->repeat_key, dev->keybit, KEY_MAX)) {
 134
 135                 input_pass_event(dev, NULL, EV_KEY, dev->repeat_key, 2);
 136
 137                 if (dev->sync) {
 138                         /*
 139                          * Only send SYN_REPORT if we are not in a middle
 140                          * of driver parsing a new hardware packet.
 141                          * Otherwise assume that the driver will send
 142                          * SYN_REPORT once it's done.
 143                          */
 144                         input_pass_event(dev, NULL, EV_SYN, SYN_REPORT, 1);
 145                 }
 146
 147                 if (dev->rep[REP_PERIOD])
 148                         mod_timer(&dev->timer, jiffies +
 149                                         msecs_to_jiffies(dev->rep[REP_PERIOD]));
 150         }
 151
 152         spin_unlock_irqrestore(&dev->event_lock, flags);
 153 }
 154
 155 static void input_start_autorepeat(struct input_dev *dev, int code)
 156 {
 157         if (test_bit(EV_REP, dev->evbit) &&
 158             dev->rep[REP_PERIOD] && dev->rep[REP_DELAY] &&
 159             dev->timer.data) {
 160                 dev->repeat_key = code;
 161                 mod_timer(&dev->timer,
 162                           jiffies + msecs_to_jiffies(dev->rep[REP_DELAY]));
 163         }
 164 }
 165
 166 static void input_stop_autorepeat(struct input_dev *dev)
 167 {
 168         del_timer(&dev->timer);
 169 }
 170
 171 #define INPUT_IGNORE_EVENT      0
 172 #define INPUT_PASS_TO_HANDLERS  1
 173 #define INPUT_PASS_TO_DEVICE    2
 174 #define INPUT_PASS_TO_ALL       (INPUT_PASS_TO_HANDLERS | INPUT_PASS_TO_DEVICE)
 175
 176 static int input_handle_abs_event(struct input_dev *dev,
 177                                   struct input_handler *src_handler,
 178                                   unsigned int code, int *pval)
 179 {
 180         bool is_mt_event;
 181         int *pold;
 182
 183         if (code == ABS_MT_SLOT) {
 184                 /*
 185                  * "Stage" the event; we'll flush it later, when we
 186                  * get actual touch data.
 187                  */
 188                 if (*pval >= 0 && *pval < dev->mtsize)
 189                         dev->slot = *pval;
 190
 191                 return INPUT_IGNORE_EVENT;
 192         }
 193
 194         is_mt_event = code >= ABS_MT_FIRST && code <= ABS_MT_LAST;
 195
 196         if (!is_mt_event) {
 197                 pold = &dev->absinfo[code].value;
 198         } else if (dev->mt) {
 199                 struct input_mt_slot *mtslot = &dev->mt[dev->slot];
 200                 pold = &mtslot->abs[code - ABS_MT_FIRST];
 201         } else {
 202                 /*
 203                  * Bypass filtering for multi-touch events when
 204                  * not employing slots.
 205                  */
 206                 pold = NULL;
 207         }
 208
 209         if (pold) {
 210                 *pval = input_defuzz_abs_event(*pval, *pold,
 211                                                 dev->absinfo[code].fuzz);
 212                 if (*pold == *pval)
 213                         return INPUT_IGNORE_EVENT;
 214
 215                 *pold = *pval;
 216         }
 217
 218         /* Flush pending "slot" event */
 219         if (is_mt_event && dev->slot != input_abs_get_val(dev, ABS_MT_SLOT)) {
 220                 input_abs_set_val(dev, ABS_MT_SLOT, dev->slot);
 221                 input_pass_event(dev, src_handler,
 222                                  EV_ABS, ABS_MT_SLOT, dev->slot);
 223         }
 224
 225         return INPUT_PASS_TO_HANDLERS;
 226 }
 227
 228 static void input_handle_event(struct input_dev *dev,
 229                                struct input_handler *src_handler,
 230                                unsigned int type, unsigned int code, int value)
 231 {
 232         int disposition = INPUT_IGNORE_EVENT;
 233
 234         switch (type) {
 235
 236         case EV_SYN:
 237                 switch (code) {
 238                 case SYN_CONFIG:
 239                         disposition = INPUT_PASS_TO_ALL;
 240                         break;
 241
 242                 case SYN_REPORT:
 243                         if (!dev->sync) {
 244                                 dev->sync = true;
 245                                 disposition = INPUT_PASS_TO_HANDLERS;
 246                         }
 247                         break;
 248                 case SYN_MT_REPORT:
 249                         dev->sync = false;
 250                         disposition = INPUT_PASS_TO_HANDLERS;
 251                         break;
 252                 }
 253                 break;
 254
 255         case EV_KEY:
 256                 if (is_event_supported(code, dev->keybit, KEY_MAX) &&
 257                     !!test_bit(code, dev->key) != value) {
 258
 259                         if (value != 2) {
 260                                 __change_bit(code, dev->key);
 261                                 if (value)
 262                                         input_start_autorepeat(dev, code);
 263                                 else
 264                                         input_stop_autorepeat(dev);
 265                         }
 266
 267                         disposition = INPUT_PASS_TO_HANDLERS;
 268                 }
 269                 break;
 270
 271         case EV_SW:
 272                 if (is_event_supported(code, dev->swbit, SW_MAX) &&
 273                     !!test_bit(code, dev->sw) != value) {
 274
 275                         __change_bit(code, dev->sw);
 276                         disposition = INPUT_PASS_TO_HANDLERS;
 277                 }
 278                 break;
 279
 280         case EV_ABS:
 281                 if (is_event_supported(code, dev->absbit, ABS_MAX))
 282                         disposition = input_handle_abs_event(dev, src_handler,
 283                                                              code, &value);
 284
 285                 break;
 286
 287         case EV_REL:
 288                 if (is_event_supported(code, dev->relbit, REL_MAX) && value)
 289                         disposition = INPUT_PASS_TO_HANDLERS;
 290
 291                 break;
 292
 293         case EV_MSC:
 294                 if (is_event_supported(code, dev->mscbit, MSC_MAX))
 295                         disposition = INPUT_PASS_TO_ALL;
 296
 297                 break;
 298
 299         case EV_LED:
 300                 if (is_event_supported(code, dev->ledbit, LED_MAX) &&
 301                     !!test_bit(code, dev->led) != value) {
 302
 303                         __change_bit(code, dev->led);
 304                         disposition = INPUT_PASS_TO_ALL;
 305                 }
 306                 break;
 307
 308         case EV_SND:
 309                 if (is_event_supported(code, dev->sndbit, SND_MAX)) {
 310
 311                         if (!!test_bit(code, dev->snd) != !!value)
 312                                 __change_bit(code, dev->snd);
 313                         disposition = INPUT_PASS_TO_ALL;
 314                 }
 315                 break;
 316
 317         case EV_REP:
 318                 if (code <= REP_MAX && value >= 0 && dev->rep[code] != value) {
 319                         dev->rep[code] = value;
 320                         disposition = INPUT_PASS_TO_ALL;
 321                 }
 322                 break;
 323
 324         case EV_FF:
 325                 if (value >= 0)
 326                         disposition = INPUT_PASS_TO_ALL;
 327                 break;
 328
 329         case EV_PWR:
 330                 disposition = INPUT_PASS_TO_ALL;
 331                 break;
 332         }
 333
 334         if (disposition != INPUT_IGNORE_EVENT && type != EV_SYN)
 335                 dev->sync = false;
 336
 337         if ((disposition & INPUT_PASS_TO_DEVICE) && dev->event)
 338                 dev->event(dev, type, code, value);
 339
 340         if (disposition & INPUT_PASS_TO_HANDLERS)
 341                 input_pass_event(dev, src_handler, type, code, value);
 342 }
 343
 344 /**
 345  * input_event() - report new input event
 346  * @dev: device that generated the event
 347  * @type: type of the event
 348  * @code: event code
 349  * @value: value of the event
 350  *
 351  * This function should be used by drivers implementing various input
 352  * devices to report input events. See also input_inject_event().
 353  *
 354  * NOTE: input_event() may be safely used right after input device was
 355  * allocated with input_allocate_device(), even before it is registered
 356  * with input_register_device(), but the event will not reach any of the
 357  * input handlers. Such early invocation of input_event() may be used
 358  * to 'seed' initial state of a switch or initial position of absolute
 359  * axis, etc.
 360  */
 361 void input_event(struct input_dev *dev,
 362                  unsigned int type, unsigned int code, int value)
 363 {
 364         unsigned long flags;
 365
 366         if (is_event_supported(type, dev->evbit, EV_MAX)) {
 367
 368                 spin_lock_irqsave(&dev->event_lock, flags);
 369                 add_input_randomness(type, code, value);
 370                 input_handle_event(dev, NULL, type, code, value);
 371                 spin_unlock_irqrestore(&dev->event_lock, flags);
 372         }
 373 }
 374 EXPORT_SYMBOL(input_event);
 375
 376 /**
 377  * input_inject_event() - send input event from input handler
 378  * @handle: input handle to send event through
 379  * @type: type of the event
 380  * @code: event code
 381  * @value: value of the event
 382  *
 383  * Similar to input_event() but will ignore event if device is
 384  * "grabbed" and handle injecting event is not the one that owns
 385  * the device.
 386  */
 387 void input_inject_event(struct input_handle *handle,
 388                         unsigned int type, unsigned int code, int value)
 389 {
 390         struct input_dev *dev = handle->dev;
 391         struct input_handle *grab;
 392         unsigned long flags;
 393
 394         if (is_event_supported(type, dev->evbit, EV_MAX)) {
 395                 spin_lock_irqsave(&dev->event_lock, flags);
 396
 397                 rcu_read_lock();
 398                 grab = rcu_dereference(dev->grab);
 399                 if (!grab || grab == handle)
 400                         input_handle_event(dev, handle->handler,
 401                                            type, code, value);
 402                 rcu_read_unlock();
 403
 404                 spin_unlock_irqrestore(&dev->event_lock, flags);
 405         }
 406 }
 407 EXPORT_SYMBOL(input_inject_event);
 408
 409 /**
 410  * input_alloc_absinfo - allocates array of input_absinfo structs
 411  * @dev: the input device emitting absolute events
 412  *
 413  * If the absinfo struct the caller asked for is already allocated, this
 414  * functions will not do anything.
 415  */
 416 void input_alloc_absinfo(struct input_dev *dev)
 417 {
 418         if (!dev->absinfo)
 419                 dev->absinfo = kcalloc(ABS_CNT, sizeof(struct input_absinfo),
 420                                         GFP_KERNEL);
 421
 422         WARN(!dev->absinfo, "%s(): kcalloc() failed?\n", __func__);
 423 }
 424 EXPORT_SYMBOL(input_alloc_absinfo);
 425
 426 void input_set_abs_params(struct input_dev *dev, unsigned int axis,
 427                           int min, int max, int fuzz, int flat)
 428 {
 429         struct input_absinfo *absinfo;
 430
 431         input_alloc_absinfo(dev);
 432         if (!dev->absinfo)
 433                 return;
 434
 435         absinfo = &dev->absinfo[axis];
 436         absinfo->minimum = min;
 437         absinfo->maximum = max;
 438         absinfo->fuzz = fuzz;
 439         absinfo->flat = flat;
 440
 441         dev->absbit[BIT_WORD(axis)] |= BIT_MASK(axis);
 442 }
 443 EXPORT_SYMBOL(input_set_abs_params);
 444
 445
 446 /**
 447  * input_grab_device - grabs device for exclusive use
 448  * @handle: input handle that wants to own the device
 449  *
 450  * When a device is grabbed by an input handle all events generated by
 451  * the device are delivered only to this handle. Also events injected
 452  * by other input handles are ignored while device is grabbed.
 453  */
 454 int input_grab_device(struct input_handle *handle)
 455 {
 456         struct input_dev *dev = handle->dev;
 457         int retval;
 458
 459         retval = mutex_lock_interruptible(&dev->mutex);
 460         if (retval)
 461                 return retval;
 462
 463         if (dev->grab) {
 464                 retval = -EBUSY;
 465                 goto out;
 466         }
 467
 468         rcu_assign_pointer(dev->grab, handle);
 469         synchronize_rcu();
 470
 471  out:
 472         mutex_unlock(&dev->mutex);
 473         return retval;
 474 }
 475 EXPORT_SYMBOL(input_grab_device);
 476
 477 static void __input_release_device(struct input_handle *handle)
 478 {
 479         struct input_dev *dev = handle->dev;
 480
 481         if (dev->grab == handle) {
 482                 rcu_assign_pointer(dev->grab, NULL);
 483                 /* Make sure input_pass_event() notices that grab is gone */
 484                 synchronize_rcu();
 485
 486                 list_for_each_entry(handle, &dev->h_list, d_node)
 487                         if (handle->open && handle->handler->start)
 488                                 handle->handler->start(handle);
 489         }
 490 }
 491
 492 /**
 493  * input_release_device - release previously grabbed device
 494  * @handle: input handle that owns the device
 495  *
 496  * Releases previously grabbed device so that other input handles can
 497  * start receiving input events. Upon release all handlers attached
 498  * to the device have their start() method called so they have a change
 499  * to synchronize device state with the rest of the system.
 500  */
 501 void input_release_device(struct input_handle *handle)
 502 {
 503         struct input_dev *dev = handle->dev;
 504
 505         mutex_lock(&dev->mutex);
 506         __input_release_device(handle);
 507         mutex_unlock(&dev->mutex);
 508 }
 509 EXPORT_SYMBOL(input_release_device);
 510
 511 /**
 512  * input_open_device - open input device
 513  * @handle: handle through which device is being accessed
 514  *
 515  * This function should be called by input handlers when they
 516  * want to start receive events from given input device.
 517  */
 518 int input_open_device(struct input_handle *handle)
 519 {
 520         struct input_dev *dev = handle->dev;
 521         int retval;
 522
 523         retval = mutex_lock_interruptible(&dev->mutex);
 524         if (retval)
 525                 return retval;
 526
 527         if (dev->going_away) {
 528                 retval = -ENODEV;
 529                 goto out;
 530         }
 531
 532         handle->open++;
 533
 534         if (!dev->users++ && dev->open)
 535                 retval = dev->open(dev);
 536
 537         if (retval) {
 538                 dev->users--;
 539                 if (!--handle->open) {
 540                         /*
 541                          * Make sure we are not delivering any more events
 542                          * through this handle
 543                          */
 544                         synchronize_rcu();
 545                 }
 546         }
 547
 548  out:
 549         mutex_unlock(&dev->mutex);
 550         return retval;
 551 }
 552 EXPORT_SYMBOL(input_open_device);
 553
 554 int input_flush_device(struct input_handle *handle, struct file *file)
 555 {
 556         struct input_dev *dev = handle->dev;
 557         int retval;
 558
 559         retval = mutex_lock_interruptible(&dev->mutex);
 560         if (retval)
 561                 return retval;
 562
 563         if (dev->flush)
 564                 retval = dev->flush(dev, file);
 565
 566         mutex_unlock(&dev->mutex);
 567         return retval;
 568 }
 569 EXPORT_SYMBOL(input_flush_device);
 570
 571 /**
 572  * input_close_device - close input device
 573  * @handle: handle through which device is being accessed
 574  *
 575  * This function should be called by input handlers when they
 576  * want to stop receive events from given input device.
 577  */
 578 void input_close_device(struct input_handle *handle)
 579 {
 580         struct input_dev *dev = handle->dev;
 581
 582         mutex_lock(&dev->mutex);
 583
 584         __input_release_device(handle);
 585
 586         if (!--dev->users && dev->close)
 587                 dev->close(dev);
 588
 589         if (!--handle->open) {
 590                 /*
 591                  * synchronize_rcu() makes sure that input_pass_event()
 592                  * completed and that no more input events are delivered
 593                  * through this handle
 594                  */
 595                 synchronize_rcu();
 596         }
 597
 598         mutex_unlock(&dev->mutex);
 599 }
 600 EXPORT_SYMBOL(input_close_device);
 601
 602 /*
 603  * Simulate keyup events for all keys that are marked as pressed.
 604  * The function must be called with dev->event_lock held.
 605  */
 606 static void input_dev_release_keys(struct input_dev *dev)
 607 {
 608         int code;
 609
 610         if (is_event_supported(EV_KEY, dev->evbit, EV_MAX)) {
 611                 for (code = 0; code <= KEY_MAX; code++) {
 612                         if (is_event_supported(code, dev->keybit, KEY_MAX) &&
 613                             __test_and_clear_bit(code, dev->key)) {
 614                                 input_pass_event(dev, NULL, EV_KEY, code, 0);
 615                         }
 616                 }
 617                 input_pass_event(dev, NULL, EV_SYN, SYN_REPORT, 1);
 618         }
 619 }
 620
 621 /*
 622  * Prepare device for unregistering
 623  */
 624 static void input_disconnect_device(struct input_dev *dev)
 625 {
 626         struct input_handle *handle;
 627
 628         /*
 629          * Mark device as going away. Note that we take dev->mutex here
 630          * not to protect access to dev->going_away but rather to ensure
 631          * that there are no threads in the middle of input_open_device()
 632          */
 633         mutex_lock(&dev->mutex);
 634         dev->going_away = true;
 635         mutex_unlock(&dev->mutex);
 636
 637         spin_lock_irq(&dev->event_lock);
 638
 639         /*
 640          * Simulate keyup events for all pressed keys so that handlers
 641          * are not left with "stuck" keys. The driver may continue
 642          * generate events even after we done here but they will not
 643          * reach any handlers.
 644          */
 645         input_dev_release_keys(dev);
 646
 647         list_for_each_entry(handle, &dev->h_list, d_node)
 648                 handle->open = 0;
 649
 650         spin_unlock_irq(&dev->event_lock);
 651 }
 652
 653 /**
 654  * input_scancode_to_scalar() - converts scancode in &struct input_keymap_entry
 655  * @ke: keymap entry containing scancode to be converted.
 656  * @scancode: pointer to the location where converted scancode should
 657  *      be stored.
 658  *
 659  * This function is used to convert scancode stored in &struct keymap_entry
 660  * into scalar form understood by legacy keymap handling methods. These
 661  * methods expect scancodes to be represented as 'unsigned int'.
 662  */
 663 int input_scancode_to_scalar(const struct input_keymap_entry *ke,
 664                              unsigned int *scancode)
 665 {
 666         switch (ke->len) {
 667         case 1:
 668                 *scancode = *((u8 *)ke->scancode);
 669                 break;
 670
 671         case 2:
 672                 *scancode = *((u16 *)ke->scancode);
 673                 break;
 674
 675         case 4:
 676                 *scancode = *((u32 *)ke->scancode);
 677                 break;
 678
 679         default:
 680                 return -EINVAL;
 681         }
 682
 683         return 0;
 684 }
 685 EXPORT_SYMBOL(input_scancode_to_scalar);
 686
 687 /*
 688  * Those routines handle the default case where no [gs]etkeycode() is
 689  * defined. In this case, an array indexed by the scancode is used.
 690  */
 691
 692 static unsigned int input_fetch_keycode(struct input_dev *dev,
 693                                         unsigned int index)
 694 {
 695         switch (dev->keycodesize) {
 696         case 1:
 697                 return ((u8 *)dev->keycode)[index];
 698
 699         case 2:
 700                 return ((u16 *)dev->keycode)[index];
 701
 702         default:
 703                 return ((u32 *)dev->keycode)[index];
 704         }
 705 }
 706
 707 static int input_default_getkeycode(struct input_dev *dev,
 708                                     struct input_keymap_entry *ke)
 709 {
 710         unsigned int index;
 711         int error;
 712
 713         if (!dev->keycodesize)
 714                 return -EINVAL;
 715
 716         if (ke->flags & INPUT_KEYMAP_BY_INDEX)
 717                 index = ke->index;
 718         else {
 719                 error = input_scancode_to_scalar(ke, &index);
 720                 if (error)
 721                         return error;
 722         }
 723
 724         if (index >= dev->keycodemax)
 725                 return -EINVAL;
 726
 727         ke->keycode = input_fetch_keycode(dev, index);
 728         ke->index = index;
 729         ke->len = sizeof(index);
 730         memcpy(ke->scancode, &index, sizeof(index));
 731
 732         return 0;
 733 }
 734
 735 static int input_default_setkeycode(struct input_dev *dev,
 736                                     const struct input_keymap_entry *ke,
 737                                     unsigned int *old_keycode)
 738 {
 739         unsigned int index;
 740         int error;
 741         int i;
 742
 743         if (!dev->keycodesize)
 744                 return -EINVAL;
 745
 746         if (ke->flags & INPUT_KEYMAP_BY_INDEX) {
 747                 index = ke->index;
 748         } else {
 749                 error = input_scancode_to_scalar(ke, &index);
 750                 if (error)
 751                         return error;
 752         }
 753
 754         if (index >= dev->keycodemax)
 755                 return -EINVAL;
 756
 757         if (dev->keycodesize < sizeof(ke->keycode) &&
 758                         (ke->keycode >> (dev->keycodesize * 8)))
 759                 return -EINVAL;
 760
 761         switch (dev->keycodesize) {
 762                 case 1: {
 763                         u8 *k = (u8 *)dev->keycode;
 764                         *old_keycode = k[index];
 765                         k[index] = ke->keycode;
 766                         break;
 767                 }
 768                 case 2: {
 769                         u16 *k = (u16 *)dev->keycode;
 770                         *old_keycode = k[index];
 771                         k[index] = ke->keycode;
 772                         break;
 773                 }
 774                 default: {
 775                         u32 *k = (u32 *)dev->keycode;
 776                         *old_keycode = k[index];
 777                         k[index] = ke->keycode;
 778                         break;
 779                 }
 780         }
 781
 782         __clear_bit(*old_keycode, dev->keybit);
 783         __set_bit(ke->keycode, dev->keybit);
 784
 785         for (i = 0; i < dev->keycodemax; i++) {
 786                 if (input_fetch_keycode(dev, i) == *old_keycode) {
 787                         __set_bit(*old_keycode, dev->keybit);
 788                         break; /* Setting the bit twice is useless, so break */
 789                 }
 790         }
 791
 792         return 0;
 793 }
 794
 795 /**
 796  * input_get_keycode - retrieve keycode currently mapped to a given scancode
 797  * @dev: input device which keymap is being queried
 798  * @ke: keymap entry
 799  *
 800  * This function should be called by anyone interested in retrieving current
 801  * keymap. Presently evdev handlers use it.
 802  */
 803 int input_get_keycode(struct input_dev *dev, struct input_keymap_entry *ke)
 804 {
 805         unsigned long flags;
 806         int retval;
 807
 808         spin_lock_irqsave(&dev->event_lock, flags);
 809
 810         if (dev->getkeycode) {
 811                 /*
 812                  * Support for legacy drivers, that don't implement the new
 813                  * ioctls
 814                  */
 815                 u32 scancode = ke->index;
 816
 817                 memcpy(ke->scancode, &scancode, sizeof(scancode));
 818                 ke->len = sizeof(scancode);
 819                 retval = dev->getkeycode(dev, scancode, &ke->keycode);
 820         } else {
 821                 retval = dev->getkeycode_new(dev, ke);
 822         }
 823
 824         spin_unlock_irqrestore(&dev->event_lock, flags);
 825         return retval;
 826 }
 827 EXPORT_SYMBOL(input_get_keycode);
 828
 829 /**
 830  * input_set_keycode - attribute a keycode to a given scancode
 831  * @dev: input device which keymap is being updated
 832  * @ke: new keymap entry
 833  *
 834  * This function should be called by anyone needing to update current
 835  * keymap. Presently keyboard and evdev handlers use it.
 836  */
 837 int input_set_keycode(struct input_dev *dev,
 838                       const struct input_keymap_entry *ke)
 839 {
 840         unsigned long flags;
 841         unsigned int old_keycode;
 842         int retval;
 843
 844         if (ke->keycode > KEY_MAX)
 845                 return -EINVAL;
 846
 847         spin_lock_irqsave(&dev->event_lock, flags);
 848
 849         if (dev->setkeycode) {
 850                 /*
 851                  * Support for legacy drivers, that don't implement the new
 852                  * ioctls
 853                  */
 854                 unsigned int scancode;
 855
 856                 retval = input_scancode_to_scalar(ke, &scancode);
 857                 if (retval)
 858                         goto out;
 859
 860                 /*
 861                  * We need to know the old scancode, in order to generate a
 862                  * keyup effect, if the set operation happens successfully
 863                  */
 864                 if (!dev->getkeycode) {
 865                         retval = -EINVAL;
 866                         goto out;
 867                 }
 868
 869                 retval = dev->getkeycode(dev, scancode, &old_keycode);
 870                 if (retval)
 871                         goto out;
 872
 873                 retval = dev->setkeycode(dev, scancode, ke->keycode);
 874         } else {
 875                 retval = dev->setkeycode_new(dev, ke, &old_keycode);
 876         }
 877
 878         if (retval)
 879                 goto out;
 880
 881         /* Make sure KEY_RESERVED did not get enabled. */
 882         __clear_bit(KEY_RESERVED, dev->keybit);
 883
 884         /*
 885          * Simulate keyup event if keycode is not present
 886          * in the keymap anymore
 887          */
 888         if (test_bit(EV_KEY, dev->evbit) &&
 889             !is_event_supported(old_keycode, dev->keybit, KEY_MAX) &&
 890             __test_and_clear_bit(old_keycode, dev->key)) {
 891
 892                 input_pass_event(dev, NULL, EV_KEY, old_keycode, 0);
 893                 if (dev->sync)
 894                         input_pass_event(dev, NULL, EV_SYN, SYN_REPORT, 1);
 895         }
 896
 897  out:
 898         spin_unlock_irqrestore(&dev->event_lock, flags);
 899
 900         return retval;
 901 }
 902 EXPORT_SYMBOL(input_set_keycode);
 903
 904 #define MATCH_BIT(bit, max) \
 905                 for (i = 0; i < BITS_TO_LONGS(max); i++) \
 906                         if ((id->bit[i] & dev->bit[i]) != id->bit[i]) \
 907                                 break; \
 908                 if (i != BITS_TO_LONGS(max)) \
 909                         continue;
 910
 911 static const struct input_device_id *input_match_device(struct input_handler *handler,
 912                                                         struct input_dev *dev)
 913 {
 914         const struct input_device_id *id;
 915         int i;
 916
 917         for (id = handler->id_table; id->flags || id->driver_info; id++) {
 918
 919                 if (id->flags & INPUT_DEVICE_ID_MATCH_BUS)
 920                         if (id->bustype != dev->id.bustype)
 921                                 continue;
 922
 923                 if (id->flags & INPUT_DEVICE_ID_MATCH_VENDOR)
 924                         if (id->vendor != dev->id.vendor)
 925                                 continue;
 926
 927                 if (id->flags & INPUT_DEVICE_ID_MATCH_PRODUCT)
 928                         if (id->product != dev->id.product)
 929                                 continue;
 930
 931                 if (id->flags & INPUT_DEVICE_ID_MATCH_VERSION)
 932                         if (id->version != dev->id.version)
 933                                 continue;
 934
 935                 MATCH_BIT(evbit,  EV_MAX);
 936                 MATCH_BIT(keybit, KEY_MAX);
 937                 MATCH_BIT(relbit, REL_MAX);
 938                 MATCH_BIT(absbit, ABS_MAX);
 939                 MATCH_BIT(mscbit, MSC_MAX);
 940                 MATCH_BIT(ledbit, LED_MAX);
 941                 MATCH_BIT(sndbit, SND_MAX);
 942                 MATCH_BIT(ffbit,  FF_MAX);
 943                 MATCH_BIT(swbit,  SW_MAX);
 944
 945                 if (!handler->match || handler->match(handler, dev))
 946                         return id;
 947         }
 948
 949         return NULL;
 950 }
 951
 952 static int input_attach_handler(struct input_dev *dev, struct input_handler *handler)
 953 {
 954         const struct input_device_id *id;
 955         int error;
 956
 957         id = input_match_device(handler, dev);
 958         if (!id)
 959                 return -ENODEV;
 960
 961         error = handler->connect(handler, dev, id);
 962         if (error && error != -ENODEV)
 963                 pr_err("failed to attach handler %s to device %s, error: %d\n",
 964                        handler->name, kobject_name(&dev->dev.kobj), error);
 965
 966         return error;
 967 }
 968
 969 #ifdef CONFIG_COMPAT
 970
 971 static int input_bits_to_string(char *buf, int buf_size,
 972                                 unsigned long bits, bool skip_empty)
 973 {
 974         int len = 0;
 975
 976         if (INPUT_COMPAT_TEST) {
 977                 u32 dword = bits >> 32;
 978                 if (dword || !skip_empty)
 979                         len += snprintf(buf, buf_size, "%x ", dword);
 980
 981                 dword = bits & 0xffffffffUL;
 982                 if (dword || !skip_empty || len)
 983                         len += snprintf(buf + len, max(buf_size - len, 0),
 984                                         "%x", dword);
 985         } else {
 986                 if (bits || !skip_empty)
 987                         len += snprintf(buf, buf_size, "%lx", bits);
 988         }
 989
 990         return len;
 991 }
 992
 993 #else /* !CONFIG_COMPAT */
 994
 995 static int input_bits_to_string(char *buf, int buf_size,
 996                                 unsigned long bits, bool skip_empty)
 997 {
 998         return bits || !skip_empty ?
 999                 snprintf(buf, buf_size, "%lx", bits) : 0;
1000 }
1001
1002 #endif
1003
1004 #ifdef CONFIG_PROC_FS
1005
1006 static struct proc_dir_entry *proc_bus_input_dir;
1007 static DECLARE_WAIT_QUEUE_HEAD(input_devices_poll_wait);
1008 static int input_devices_state;
1009
1010 static inline void input_wakeup_procfs_readers(void)
1011 {
1012         input_devices_state++;
1013         wake_up(&input_devices_poll_wait);
1014 }
1015
1016 static unsigned int input_proc_devices_poll(struct file *file, poll_table *wait)
1017 {
1018         poll_wait(file, &input_devices_poll_wait, wait);
1019         if (file->f_version != input_devices_state) {
1020                 file->f_version = input_devices_state;
1021                 return POLLIN | POLLRDNORM;
1022         }
1023
1024         return 0;
1025 }
1026
1027 union input_seq_state {
1028         struct {
1029                 unsigned short pos;
1030                 bool mutex_acquired;
1031         };
1032         void *p;
1033 };
1034
1035 static void *input_devices_seq_start(struct seq_file *seq, loff_t *pos)
1036 {
1037         union input_seq_state *state = (union input_seq_state *)&seq->private;
1038         int error;
1039
1040         /* We need to fit into seq->private pointer */
1041         BUILD_BUG_ON(sizeof(union input_seq_state) != sizeof(seq->private));
1042
1043         error = mutex_lock_interruptible(&input_mutex);
1044         if (error) {
1045                 state->mutex_acquired = false;
1046                 return ERR_PTR(error);
1047         }
1048
1049         state->mutex_acquired = true;
1050
1051         return seq_list_start(&input_dev_list, *pos);
1052 }
1053
1054 static void *input_devices_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1055 {
1056         return seq_list_next(v, &input_dev_list, pos);
1057 }
1058
1059 static void input_seq_stop(struct seq_file *seq, void *v)
1060 {
1061         union input_seq_state *state = (union input_seq_state *)&seq->private;
1062
1063         if (state->mutex_acquired)
1064                 mutex_unlock(&input_mutex);
1065 }
1066
1067 static void input_seq_print_bitmap(struct seq_file *seq, const char *name,
1068                                    unsigned long *bitmap, int max)
1069 {
1070         int i;
1071         bool skip_empty = true;
1072         char buf[18];
1073
1074         seq_printf(seq, "B: %s=", name);
1075
1076         for (i = BITS_TO_LONGS(max) - 1; i >= 0; i--) {
1077                 if (input_bits_to_string(buf, sizeof(buf),
1078                                          bitmap[i], skip_empty)) {
1079                         skip_empty = false;
1080                         seq_printf(seq, "%s%s", buf, i > 0 ? " " : "");
1081                 }
1082         }
1083
1084         /*
1085          * If no output was produced print a single 0.
1086          */
1087         if (skip_empty)
1088                 seq_puts(seq, "0");
1089
1090         seq_putc(seq, '\n');
1091 }
1092
1093 static int input_devices_seq_show(struct seq_file *seq, void *v)
1094 {
1095         struct input_dev *dev = container_of(v, struct input_dev, node);
1096         const char *path = kobject_get_path(&dev->dev.kobj, GFP_KERNEL);
1097         struct input_handle *handle;
1098
1099         seq_printf(seq, "I: Bus=%04x Vendor=%04x Product=%04x Version=%04x\n",
1100                    dev->id.bustype, dev->id.vendor, dev->id.product, dev->id.version);
1101
1102         seq_printf(seq, "N: Name=\"%s\"\n", dev->name ? dev->name : "");
1103         seq_printf(seq, "P: Phys=%s\n", dev->phys ? dev->phys : "");
1104         seq_printf(seq, "S: Sysfs=%s\n", path ? path : "");
1105         seq_printf(seq, "U: Uniq=%s\n", dev->uniq ? dev->uniq : "");
1106         seq_printf(seq, "H: Handlers=");
1107
1108         list_for_each_entry(handle, &dev->h_list, d_node)
1109                 seq_printf(seq, "%s ", handle->name);
1110         seq_putc(seq, '\n');
1111
1112         input_seq_print_bitmap(seq, "PROP", dev->propbit, INPUT_PROP_MAX);
1113
1114         input_seq_print_bitmap(seq, "EV", dev->evbit, EV_MAX);
1115         if (test_bit(EV_KEY, dev->evbit))
1116                 input_seq_print_bitmap(seq, "KEY", dev->keybit, KEY_MAX);
1117         if (test_bit(EV_REL, dev->evbit))
1118                 input_seq_print_bitmap(seq, "REL", dev->relbit, REL_MAX);
1119         if (test_bit(EV_ABS, dev->evbit))
1120                 input_seq_print_bitmap(seq, "ABS", dev->absbit, ABS_MAX);
1121         if (test_bit(EV_MSC, dev->evbit))
1122                 input_seq_print_bitmap(seq, "MSC", dev->mscbit, MSC_MAX);
1123         if (test_bit(EV_LED, dev->evbit))
1124                 input_seq_print_bitmap(seq, "LED", dev->ledbit, LED_MAX);
1125         if (test_bit(EV_SND, dev->evbit))
1126                 input_seq_print_bitmap(seq, "SND", dev->sndbit, SND_MAX);
1127         if (test_bit(EV_FF, dev->evbit))
1128                 input_seq_print_bitmap(seq, "FF", dev->ffbit, FF_MAX);
1129         if (test_bit(EV_SW, dev->evbit))
1130                 input_seq_print_bitmap(seq, "SW", dev->swbit, SW_MAX);
1131
1132         seq_putc(seq, '\n');
1133
1134         kfree(path);
1135         return 0;
1136 }
1137
1138 static const struct seq_operations input_devices_seq_ops = {
1139         .start  = input_devices_seq_start,
1140         .next   = input_devices_seq_next,
1141         .stop   = input_seq_stop,
1142         .show   = input_devices_seq_show,
1143 };
1144
1145 static int input_proc_devices_open(struct inode *inode, struct file *file)
1146 {
1147         return seq_open(file, &input_devices_seq_ops);
1148 }
1149
1150 static const struct file_operations input_devices_fileops = {
1151         .owner          = THIS_MODULE,
1152         .open           = input_proc_devices_open,
1153         .poll           = input_proc_devices_poll,
1154         .read           = seq_read,
1155         .llseek         = seq_lseek,
1156         .release        = seq_release,
1157 };
1158
1159 static void *input_handlers_seq_start(struct seq_file *seq, loff_t *pos)
1160 {
1161         union input_seq_state *state = (union input_seq_state *)&seq->private;
1162         int error;
1163
1164         /* We need to fit into seq->private pointer */
1165         BUILD_BUG_ON(sizeof(union input_seq_state) != sizeof(seq->private));
1166
1167         error = mutex_lock_interruptible(&input_mutex);
1168         if (error) {
1169                 state->mutex_acquired = false;
1170                 return ERR_PTR(error);
1171         }
1172
1173         state->mutex_acquired = true;
1174         state->pos = *pos;
1175
1176         return seq_list_start(&input_handler_list, *pos);
1177 }
1178
1179 static void *input_handlers_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1180 {
1181         union input_seq_state *state = (union input_seq_state *)&seq->private;
1182
1183         state->pos = *pos + 1;
1184         return seq_list_next(v, &input_handler_list, pos);
1185 }
1186
1187 static int input_handlers_seq_show(struct seq_file *seq, void *v)
1188 {
1189         struct input_handler *handler = container_of(v, struct input_handler, node);
1190         union input_seq_state *state = (union input_seq_state *)&seq->private;
1191
1192         seq_printf(seq, "N: Number=%u Name=%s", state->pos, handler->name);
1193         if (handler->filter)
1194                 seq_puts(seq, " (filter)");
1195         if (handler->fops)
1196                 seq_printf(seq, " Minor=%d", handler->minor);
1197         seq_putc(seq, '\n');
1198
1199         return 0;
1200 }
1201
1202 static const struct seq_operations input_handlers_seq_ops = {
1203         .start  = input_handlers_seq_start,
1204         .next   = input_handlers_seq_next,
1205         .stop   = input_seq_stop,
1206         .show   = input_handlers_seq_show,
1207 };
1208
1209 static int input_proc_handlers_open(struct inode *inode, struct file *file)
1210 {
1211         return seq_open(file, &input_handlers_seq_ops);
1212 }
1213
1214 static const struct file_operations input_handlers_fileops = {
1215         .owner          = THIS_MODULE,
1216         .open           = input_proc_handlers_open,
1217         .read           = seq_read,
1218         .llseek         = seq_lseek,
1219         .release        = seq_release,
1220 };
1221
1222 static int __init input_proc_init(void)
1223 {
1224         struct proc_dir_entry *entry;
1225
1226         proc_bus_input_dir = proc_mkdir("bus/input", NULL);
1227         if (!proc_bus_input_dir)
1228                 return -ENOMEM;
1229
1230         entry = proc_create("devices", 0, proc_bus_input_dir,
1231                             &input_devices_fileops);
1232         if (!entry)
1233                 goto fail1;
1234
1235         entry = proc_create("handlers", 0, proc_bus_input_dir,
1236                             &input_handlers_fileops);
1237         if (!entry)
1238                 goto fail2;
1239
1240         return 0;
1241
1242  fail2: remove_proc_entry("devices", proc_bus_input_dir);
1243  fail1: remove_proc_entry("bus/input", NULL);
1244         return -ENOMEM;
1245 }
1246
1247 static void input_proc_exit(void)
1248 {
1249         remove_proc_entry("devices", proc_bus_input_dir);
1250         remove_proc_entry("handlers", proc_bus_input_dir);
1251         remove_proc_entry("bus/input", NULL);
1252 }
1253
1254 #else /* !CONFIG_PROC_FS */
1255 static inline void input_wakeup_procfs_readers(void) { }
1256 static inline int input_proc_init(void) { return 0; }
1257 static inline void input_proc_exit(void) { }
1258 #endif
1259
1260 #define INPUT_DEV_STRING_ATTR_SHOW(name)                                \
1261 static ssize_t input_dev_show_##name(struct device *dev,                \
1262                                      struct device_attribute *attr,     \
1263                                      char *buf)                         \
1264 {                                                                       \
1265         struct input_dev *input_dev = to_input_dev(dev);                \
1266                                                                         \
1267         return scnprintf(buf, PAGE_SIZE, "%s\n",                        \
1268                          input_dev->name ? input_dev->name : "");       \
1269 }                                                                       \
1270 static DEVICE_ATTR(name, S_IRUGO, input_dev_show_##name, NULL)
1271
1272 INPUT_DEV_STRING_ATTR_SHOW(name);
1273 INPUT_DEV_STRING_ATTR_SHOW(phys);
1274 INPUT_DEV_STRING_ATTR_SHOW(uniq);
1275
1276 static int input_print_modalias_bits(char *buf, int size,
1277                                      char name, unsigned long *bm,
1278                                      unsigned int min_bit, unsigned int max_bit)
1279 {
1280         int len = 0, i;
1281
1282         len += snprintf(buf, max(size, 0), "%c", name);
1283         for (i = min_bit; i < max_bit; i++)
1284                 if (bm[BIT_WORD(i)] & BIT_MASK(i))
1285                         len += snprintf(buf + len, max(size - len, 0), "%X,", i);
1286         return len;
1287 }
1288
1289 static int input_print_modalias(char *buf, int size, struct input_dev *id,
1290                                 int add_cr)
1291 {
1292         int len;
1293
1294         len = snprintf(buf, max(size, 0),
1295                        "input:b%04Xv%04Xp%04Xe%04X-",
1296                        id->id.bustype, id->id.vendor,
1297                        id->id.product, id->id.version);
1298
1299         len += input_print_modalias_bits(buf + len, size - len,
1300                                 'e', id->evbit, 0, EV_MAX);
1301         len += input_print_modalias_bits(buf + len, size - len,
1302                                 'k', id->keybit, KEY_MIN_INTERESTING, KEY_MAX);
1303         len += input_print_modalias_bits(buf + len, size - len,
1304                                 'r', id->relbit, 0, REL_MAX);
1305         len += input_print_modalias_bits(buf + len, size - len,
1306                                 'a', id->absbit, 0, ABS_MAX);
1307         len += input_print_modalias_bits(buf + len, size - len,
1308                                 'm', id->mscbit, 0, MSC_MAX);
1309         len += input_print_modalias_bits(buf + len, size - len,
1310                                 'l', id->ledbit, 0, LED_MAX);
1311         len += input_print_modalias_bits(buf + len, size - len,
1312                                 's', id->sndbit, 0, SND_MAX);
1313         len += input_print_modalias_bits(buf + len, size - len,
1314                                 'f', id->ffbit, 0, FF_MAX);
1315         len += input_print_modalias_bits(buf + len, size - len,
1316                                 'w', id->swbit, 0, SW_MAX);
1317
1318         if (add_cr)
1319                 len += snprintf(buf + len, max(size - len, 0), "\n");
1320
1321         return len;
1322 }
1323
1324 static ssize_t input_dev_show_modalias(struct device *dev,
1325                                        struct device_attribute *attr,
1326                                        char *buf)
1327 {
1328         struct input_dev *id = to_input_dev(dev);
1329         ssize_t len;
1330
1331         len = input_print_modalias(buf, PAGE_SIZE, id, 1);
1332
1333         return min_t(int, len, PAGE_SIZE);
1334 }
1335 static DEVICE_ATTR(modalias, S_IRUGO, input_dev_show_modalias, NULL);
1336
1337 static int input_print_bitmap(char *buf, int buf_size, unsigned long *bitmap,
1338                               int max, int add_cr);
1339
1340 static ssize_t input_dev_show_properties(struct device *dev,
1341                                          struct device_attribute *attr,
1342                                          char *buf)
1343 {
1344         struct input_dev *input_dev = to_input_dev(dev);
1345         int len = input_print_bitmap(buf, PAGE_SIZE, input_dev->propbit,
1346                                      INPUT_PROP_MAX, true);
1347         return min_t(int, len, PAGE_SIZE);
1348 }
1349 static DEVICE_ATTR(properties, S_IRUGO, input_dev_show_properties, NULL);
1350
1351 static struct attribute *input_dev_attrs[] = {
1352         &dev_attr_name.attr,
1353         &dev_attr_phys.attr,
1354         &dev_attr_uniq.attr,
1355         &dev_attr_modalias.attr,
1356         &dev_attr_properties.attr,
1357         NULL
1358 };
1359
1360 static struct attribute_group input_dev_attr_group = {
1361         .attrs  = input_dev_attrs,
1362 };
1363
1364 #define INPUT_DEV_ID_ATTR(name)                                         \
1365 static ssize_t input_dev_show_id_##name(struct device *dev,             \
1366                                         struct device_attribute *attr,  \
1367                                         char *buf)                      \
1368 {                                                                       \
1369         struct input_dev *input_dev = to_input_dev(dev);                \
1370         return scnprintf(buf, PAGE_SIZE, "%04x\n", input_dev->id.name); \
1371 }                                                                       \
1372 static DEVICE_ATTR(name, S_IRUGO, input_dev_show_id_##name, NULL)
1373
1374 INPUT_DEV_ID_ATTR(bustype);
1375 INPUT_DEV_ID_ATTR(vendor);
1376 INPUT_DEV_ID_ATTR(product);
1377 INPUT_DEV_ID_ATTR(version);
1378
1379 static struct attribute *input_dev_id_attrs[] = {
1380         &dev_attr_bustype.attr,
1381         &dev_attr_vendor.attr,
1382         &dev_attr_product.attr,
1383         &dev_attr_version.attr,
1384         NULL
1385 };
1386
1387 static struct attribute_group input_dev_id_attr_group = {
1388         .name   = "id",
1389         .attrs  = input_dev_id_attrs,
1390 };
1391
1392 static int input_print_bitmap(char *buf, int buf_size, unsigned long *bitmap,
1393                               int max, int add_cr)
1394 {
1395         int i;
1396         int len = 0;
1397         bool skip_empty = true;
1398
1399         for (i = BITS_TO_LONGS(max) - 1; i >= 0; i--) {
1400                 len += input_bits_to_string(buf + len, max(buf_size - len, 0),
1401                                             bitmap[i], skip_empty);
1402                 if (len) {
1403                         skip_empty = false;
1404                         if (i > 0)
1405                                 len += snprintf(buf + len, max(buf_size - len, 0), " ");
1406                 }
1407         }
1408
1409         /*
1410          * If no output was produced print a single 0.
1411          */
1412         if (len == 0)
1413                 len = snprintf(buf, buf_size, "%d", 0);
1414
1415         if (add_cr)
1416                 len += snprintf(buf + len, max(buf_size - len, 0), "\n");
1417
1418         return len;
1419 }
1420
1421 #define INPUT_DEV_CAP_ATTR(ev, bm)                                      \
1422 static ssize_t input_dev_show_cap_##bm(struct device *dev,              \
1423                                        struct device_attribute *attr,   \
1424                                        char *buf)                       \
1425 {                                                                       \
1426         struct input_dev *input_dev = to_input_dev(dev);                \
1427         int len = input_print_bitmap(buf, PAGE_SIZE,                    \
1428                                      input_dev->bm##bit, ev##_MAX,      \
1429                                      true);                             \
1430         return min_t(int, len, PAGE_SIZE);                              \
1431 }                                                                       \
1432 static DEVICE_ATTR(bm, S_IRUGO, input_dev_show_cap_##bm, NULL)
1433
1434 INPUT_DEV_CAP_ATTR(EV, ev);
1435 INPUT_DEV_CAP_ATTR(KEY, key);
1436 INPUT_DEV_CAP_ATTR(REL, rel);
1437 INPUT_DEV_CAP_ATTR(ABS, abs);
1438 INPUT_DEV_CAP_ATTR(MSC, msc);
1439 INPUT_DEV_CAP_ATTR(LED, led);
1440 INPUT_DEV_CAP_ATTR(SND, snd);
1441 INPUT_DEV_CAP_ATTR(FF, ff);
1442 INPUT_DEV_CAP_ATTR(SW, sw);
1443
1444 static struct attribute *input_dev_caps_attrs[] = {
1445         &dev_attr_ev.attr,
1446         &dev_attr_key.attr,
1447         &dev_attr_rel.attr,
1448         &dev_attr_abs.attr,
1449         &dev_attr_msc.attr,
1450         &dev_attr_led.attr,
1451         &dev_attr_snd.attr,
1452         &dev_attr_ff.attr,
1453         &dev_attr_sw.attr,
1454         NULL
1455 };
1456
1457 static struct attribute_group input_dev_caps_attr_group = {
1458         .name   = "capabilities",
1459         .attrs  = input_dev_caps_attrs,
1460 };
1461
1462 static const struct attribute_group *input_dev_attr_groups[] = {
1463         &input_dev_attr_group,
1464         &input_dev_id_attr_group,
1465         &input_dev_caps_attr_group,
1466         NULL
1467 };
1468
1469 static void input_dev_release(struct device *device)
1470 {
1471         struct input_dev *dev = to_input_dev(device);
1472
1473         input_ff_destroy(dev);
1474         input_mt_destroy_slots(dev);
1475         kfree(dev->absinfo);
1476         kfree(dev);
1477
1478         module_put(THIS_MODULE);
1479 }
1480
1481 /*
1482  * Input uevent interface - loading event handlers based on
1483  * device bitfields.
1484  */
1485 static int input_add_uevent_bm_var(struct kobj_uevent_env *env,
1486                                    const char *name, unsigned long *bitmap, int max)
1487 {
1488         int len;
1489
1490         if (add_uevent_var(env, "%s", name))
1491                 return -ENOMEM;
1492
1493         len = input_print_bitmap(&env->buf[env->buflen - 1],
1494                                  sizeof(env->buf) - env->buflen,
1495                                  bitmap, max, false);
1496         if (len >= (sizeof(env->buf) - env->buflen))
1497                 return -ENOMEM;
1498
1499         env->buflen += len;
1500         return 0;
1501 }
1502
1503 static int input_add_uevent_modalias_var(struct kobj_uevent_env *env,
1504                                          struct input_dev *dev)
1505 {
1506         int len;
1507
1508         if (add_uevent_var(env, "MODALIAS="))
1509                 return -ENOMEM;
1510
1511         len = input_print_modalias(&env->buf[env->buflen - 1],
1512                                    sizeof(env->buf) - env->buflen,
1513                                    dev, 0);
1514         if (len >= (sizeof(env->buf) - env->buflen))
1515                 return -ENOMEM;
1516
1517         env->buflen += len;
1518         return 0;
1519 }
1520
1521 #define INPUT_ADD_HOTPLUG_VAR(fmt, val...)                              \
1522         do {                                                            \
1523                 int err = add_uevent_var(env, fmt, val);                \
1524                 if (err)                                                \
1525                         return err;                                     \
1526         } while (0)
1527
1528 #define INPUT_ADD_HOTPLUG_BM_VAR(name, bm, max)                         \
1529         do {                                                            \
1530                 int err = input_add_uevent_bm_var(env, name, bm, max);  \
1531                 if (err)                                                \
1532                         return err;                                     \
1533         } while (0)
1534
1535 #define INPUT_ADD_HOTPLUG_MODALIAS_VAR(dev)                             \
1536         do {                                                            \
1537                 int err = input_add_uevent_modalias_var(env, dev);      \
1538                 if (err)                                                \
1539                         return err;                                     \
1540         } while (0)
1541
1542 static int input_dev_uevent(struct device *device, struct kobj_uevent_env *env)
1543 {
1544         struct input_dev *dev = to_input_dev(device);
1545
1546         INPUT_ADD_HOTPLUG_VAR("PRODUCT=%x/%x/%x/%x",
1547                                 dev->id.bustype, dev->id.vendor,
1548                                 dev->id.product, dev->id.version);
1549         if (dev->name)
1550                 INPUT_ADD_HOTPLUG_VAR("NAME=\"%s\"", dev->name);
1551         if (dev->phys)
1552                 INPUT_ADD_HOTPLUG_VAR("PHYS=\"%s\"", dev->phys);
1553         if (dev->uniq)
1554                 INPUT_ADD_HOTPLUG_VAR("UNIQ=\"%s\"", dev->uniq);
1555
1556         INPUT_ADD_HOTPLUG_BM_VAR("PROP=", dev->propbit, INPUT_PROP_MAX);
1557
1558         INPUT_ADD_HOTPLUG_BM_VAR("EV=", dev->evbit, EV_MAX);
1559         if (test_bit(EV_KEY, dev->evbit))
1560                 INPUT_ADD_HOTPLUG_BM_VAR("KEY=", dev->keybit, KEY_MAX);
1561         if (test_bit(EV_REL, dev->evbit))
1562                 INPUT_ADD_HOTPLUG_BM_VAR("REL=", dev->relbit, REL_MAX);
1563         if (test_bit(EV_ABS, dev->evbit))
1564                 INPUT_ADD_HOTPLUG_BM_VAR("ABS=", dev->absbit, ABS_MAX);
1565         if (test_bit(EV_MSC, dev->evbit))
1566                 INPUT_ADD_HOTPLUG_BM_VAR("MSC=", dev->mscbit, MSC_MAX);
1567         if (test_bit(EV_LED, dev->evbit))
1568                 INPUT_ADD_HOTPLUG_BM_VAR("LED=", dev->ledbit, LED_MAX);
1569         if (test_bit(EV_SND, dev->evbit))
1570                 INPUT_ADD_HOTPLUG_BM_VAR("SND=", dev->sndbit, SND_MAX);
1571         if (test_bit(EV_FF, dev->evbit))
1572                 INPUT_ADD_HOTPLUG_BM_VAR("FF=", dev->ffbit, FF_MAX);
1573         if (test_bit(EV_SW, dev->evbit))
1574                 INPUT_ADD_HOTPLUG_BM_VAR("SW=", dev->swbit, SW_MAX);
1575
1576         INPUT_ADD_HOTPLUG_MODALIAS_VAR(dev);
1577
1578         return 0;
1579 }
1580
1581 #define INPUT_DO_TOGGLE(dev, type, bits, on)                            \
1582         do {                                                            \
1583                 int i;                                                  \
1584                 bool active;                                            \
1585                                                                         \
1586                 if (!test_bit(EV_##type, dev->evbit))                   \
1587                         break;                                          \
1588                                                                         \
1589                 for (i = 0; i < type##_MAX; i++) {                      \
1590                         if (!test_bit(i, dev->bits##bit))               \
1591                                 continue;                               \
1592                                                                         \
1593                         active = test_bit(i, dev->bits);                \
1594                         if (!active && !on)                             \
1595                                 continue;                               \
1596                                                                         \
1597                         dev->event(dev, EV_##type, i, on ? active : 0); \
1598                 }                                                       \
1599         } while (0)
1600
1601 static void input_dev_toggle(struct input_dev *dev, bool activate)
1602 {
1603         if (!dev->event)
1604                 return;
1605
1606         INPUT_DO_TOGGLE(dev, LED, led, activate);
1607         INPUT_DO_TOGGLE(dev, SND, snd, activate);
1608
1609         if (activate && test_bit(EV_REP, dev->evbit)) {
1610                 dev->event(dev, EV_REP, REP_PERIOD, dev->rep[REP_PERIOD]);
1611                 dev->event(dev, EV_REP, REP_DELAY, dev->rep[REP_DELAY]);
1612         }
1613 }
1614
1615 /**
1616  * input_reset_device() - reset/restore the state of input device
1617  * @dev: input device whose state needs to be reset
1618  *
1619  * This function tries to reset the state of an opened input device and
1620  * bring internal state and state if the hardware in sync with each other.
1621  * We mark all keys as released, restore LED state, repeat rate, etc.
1622  */
1623 void input_reset_device(struct input_dev *dev)
1624 {
1625         mutex_lock(&dev->mutex);
1626
1627         if (dev->users) {
1628                 input_dev_toggle(dev, true);
1629
1630                 /*
1631                  * Keys that have been pressed at suspend time are unlikely
1632                  * to be still pressed when we resume.
1633                  */
1634                 spin_lock_irq(&dev->event_lock);
1635                 input_dev_release_keys(dev);
1636                 spin_unlock_irq(&dev->event_lock);
1637         }
1638
1639         mutex_unlock(&dev->mutex);
1640 }
1641 EXPORT_SYMBOL(input_reset_device);
1642
1643 #ifdef CONFIG_PM
1644 static int input_dev_suspend(struct device *dev)
1645 {
1646         struct input_dev *input_dev = to_input_dev(dev);
1647
1648         mutex_lock(&input_dev->mutex);
1649
1650         if (input_dev->users)
1651                 input_dev_toggle(input_dev, false);
1652
1653         mutex_unlock(&input_dev->mutex);
1654
1655         return 0;
1656 }
1657
1658 static int input_dev_resume(struct device *dev)
1659 {
1660         struct input_dev *input_dev = to_input_dev(dev);
1661
1662         input_reset_device(input_dev);
1663
1664         return 0;
1665 }
1666
1667 static const struct dev_pm_ops input_dev_pm_ops = {
1668         .suspend        = input_dev_suspend,
1669         .resume         = input_dev_resume,
1670         .poweroff       = input_dev_suspend,
1671         .restore        = input_dev_resume,
1672 };
1673 #endif /* CONFIG_PM */
1674
1675 static struct device_type input_dev_type = {
1676         .groups         = input_dev_attr_groups,
1677         .release        = input_dev_release,
1678         .uevent         = input_dev_uevent,
1679 #ifdef CONFIG_PM
1680         .pm             = &input_dev_pm_ops,
1681 #endif
1682 };
1683
1684 static char *input_devnode(struct device *dev, mode_t *mode)
1685 {
1686         return kasprintf(GFP_KERNEL, "input/%s", dev_name(dev));
1687 }
1688
1689 struct class input_class = {
1690         .name           = "input",
1691         .devnode        = input_devnode,
1692 };
1693 EXPORT_SYMBOL_GPL(input_class);
1694
1695 /**
1696  * input_allocate_device - allocate memory for new input device
1697  *
1698  * Returns prepared struct input_dev or NULL.
1699  *
1700  * NOTE: Use input_free_device() to free devices that have not been
1701  * registered; input_unregister_device() should be used for already
1702  * registered devices.
1703  */
1704 struct input_dev *input_allocate_device(void)
1705 {
1706         struct input_dev *dev;
1707
1708         dev = kzalloc(sizeof(struct input_dev), GFP_KERNEL);
1709         if (dev) {
1710                 dev->dev.type = &input_dev_type;
1711                 dev->dev.class = &input_class;
1712                 device_initialize(&dev->dev);
1713                 mutex_init(&dev->mutex);
1714                 spin_lock_init(&dev->event_lock);
1715                 INIT_LIST_HEAD(&dev->h_list);
1716                 INIT_LIST_HEAD(&dev->node);
1717
1718                 __module_get(THIS_MODULE);
1719         }
1720
1721         return dev;
1722 }
1723 EXPORT_SYMBOL(input_allocate_device);
1724
1725 /**
1726  * input_free_device - free memory occupied by input_dev structure
1727  * @dev: input device to free
1728  *
1729  * This function should only be used if input_register_device()
1730  * was not called yet or if it failed. Once device was registered
1731  * use input_unregister_device() and memory will be freed once last
1732  * reference to the device is dropped.
1733  *
1734  * Device should be allocated by input_allocate_device().
1735  *
1736  * NOTE: If there are references to the input device then memory
1737  * will not be freed until last reference is dropped.
1738  */
1739 void input_free_device(struct input_dev *dev)
1740 {
1741         if (dev)
1742                 input_put_device(dev);
1743 }
1744 EXPORT_SYMBOL(input_free_device);
1745
1746 /**
1747  * input_set_capability - mark device as capable of a certain event
1748  * @dev: device that is capable of emitting or accepting event
1749  * @type: type of the event (EV_KEY, EV_REL, etc...)
1750  * @code: event code
1751  *
1752  * In addition to setting up corresponding bit in appropriate capability
1753  * bitmap the function also adjusts dev->evbit.
1754  */
1755 void input_set_capability(struct input_dev *dev, unsigned int type, unsigned int code)
1756 {
1757         switch (type) {
1758         case EV_KEY:
1759                 __set_bit(code, dev->keybit);
1760                 break;
1761
1762         case EV_REL:
1763                 __set_bit(code, dev->relbit);
1764                 break;
1765
1766         case EV_ABS:
1767                 __set_bit(code, dev->absbit);
1768                 break;
1769
1770         case EV_MSC:
1771                 __set_bit(code, dev->mscbit);
1772                 break;
1773
1774         case EV_SW:
1775                 __set_bit(code, dev->swbit);
1776                 break;
1777
1778         case EV_LED:
1779                 __set_bit(code, dev->ledbit);
1780                 break;
1781
1782         case EV_SND:
1783                 __set_bit(code, dev->sndbit);
1784                 break;
1785
1786         case EV_FF:
1787                 __set_bit(code, dev->ffbit);
1788                 break;
1789
1790         case EV_PWR:
1791                 /* do nothing */
1792                 break;
1793
1794         default:
1795                 pr_err("input_set_capability: unknown type %u (code %u)\n",
1796                        type, code);
1797                 dump_stack();
1798                 return;
1799         }
1800
1801         __set_bit(type, dev->evbit);
1802 }
1803 EXPORT_SYMBOL(input_set_capability);
1804
1805 #define INPUT_CLEANSE_BITMASK(dev, type, bits)                          \
1806         do {                                                            \
1807                 if (!test_bit(EV_##type, dev->evbit))                   \
1808                         memset(dev->bits##bit, 0,                       \
1809                                 sizeof(dev->bits##bit));                \
1810         } while (0)
1811
1812 static void input_cleanse_bitmasks(struct input_dev *dev)
1813 {
1814         INPUT_CLEANSE_BITMASK(dev, KEY, key);
1815         INPUT_CLEANSE_BITMASK(dev, REL, rel);
1816         INPUT_CLEANSE_BITMASK(dev, ABS, abs);
1817         INPUT_CLEANSE_BITMASK(dev, MSC, msc);
1818         INPUT_CLEANSE_BITMASK(dev, LED, led);
1819         INPUT_CLEANSE_BITMASK(dev, SND, snd);
1820         INPUT_CLEANSE_BITMASK(dev, FF, ff);
1821         INPUT_CLEANSE_BITMASK(dev, SW, sw);
1822 }
1823
1824 /**
1825  * input_register_device - register device with input core
1826  * @dev: device to be registered
1827  *
1828  * This function registers device with input core. The device must be
1829  * allocated with input_allocate_device() and all it's capabilities
1830  * set up before registering.
1831  * If function fails the device must be freed with input_free_device().
1832  * Once device has been successfully registered it can be unregistered
1833  * with input_unregister_device(); input_free_device() should not be
1834  * called in this case.
1835  */
1836 int input_register_device(struct input_dev *dev)
1837 {
1838         static atomic_t input_no = ATOMIC_INIT(0);
1839         struct input_handler *handler;
1840         const char *path;
1841         int error;
1842
1843         /* Every input device generates EV_SYN/SYN_REPORT events. */
1844         __set_bit(EV_SYN, dev->evbit);
1845
1846         /* KEY_RESERVED is not supposed to be transmitted to userspace. */
1847         __clear_bit(KEY_RESERVED, dev->keybit);
1848
1849         /* Make sure that bitmasks not mentioned in dev->evbit are clean. */
1850         input_cleanse_bitmasks(dev);
1851
1852         /*
1853          * If delay and period are pre-set by the driver, then autorepeating
1854          * is handled by the driver itself and we don't do it in input.c.
1855          */
1856         init_timer(&dev->timer);
1857         if (!dev->rep[REP_DELAY] && !dev->rep[REP_PERIOD]) {
1858                 dev->timer.data = (long) dev;
1859                 dev->timer.function = input_repeat_key;
1860                 dev->rep[REP_DELAY] = 250;
1861                 dev->rep[REP_PERIOD] = 33;
1862         }
1863
1864         if (!dev->getkeycode && !dev->getkeycode_new)
1865                 dev->getkeycode_new = input_default_getkeycode;
1866
1867         if (!dev->setkeycode && !dev->setkeycode_new)
1868                 dev->setkeycode_new = input_default_setkeycode;
1869
1870         dev_set_name(&dev->dev, "input%ld",
1871                      (unsigned long) atomic_inc_return(&input_no) - 1);
1872
1873         error = device_add(&dev->dev);
1874         if (error)
1875                 return error;
1876
1877         path = kobject_get_path(&dev->dev.kobj, GFP_KERNEL);
1878         pr_info("%s as %s\n",
1879                 dev->name ? dev->name : "Unspecified device",
1880                 path ? path : "N/A");
1881         kfree(path);
1882
1883         error = mutex_lock_interruptible(&input_mutex);
1884         if (error) {
1885                 device_del(&dev->dev);
1886                 return error;
1887         }
1888
1889         list_add_tail(&dev->node, &input_dev_list);
1890
1891         list_for_each_entry(handler, &input_handler_list, node)
1892                 input_attach_handler(dev, handler);
1893
1894         input_wakeup_procfs_readers();
1895
1896         mutex_unlock(&input_mutex);
1897
1898         return 0;
1899 }
1900 EXPORT_SYMBOL(input_register_device);
1901
1902 /**
1903  * input_unregister_device - unregister previously registered device
1904  * @dev: device to be unregistered
1905  *
1906  * This function unregisters an input device. Once device is unregistered
1907  * the caller should not try to access it as it may get freed at any moment.
1908  */
1909 void input_unregister_device(struct input_dev *dev)
1910 {
1911         struct input_handle *handle, *next;
1912
1913         input_disconnect_device(dev);
1914
1915         mutex_lock(&input_mutex);
1916
1917         list_for_each_entry_safe(handle, next, &dev->h_list, d_node)
1918                 handle->handler->disconnect(handle);
1919         WARN_ON(!list_empty(&dev->h_list));
1920
1921         del_timer_sync(&dev->timer);
1922         list_del_init(&dev->node);
1923
1924         input_wakeup_procfs_readers();
1925
1926         mutex_unlock(&input_mutex);
1927
1928         device_unregister(&dev->dev);
1929 }
1930 EXPORT_SYMBOL(input_unregister_device);
1931
1932 /**
1933  * input_register_handler - register a new input handler
1934  * @handler: handler to be registered
1935  *
1936  * This function registers a new input handler (interface) for input
1937  * devices in the system and attaches it to all input devices that
1938  * are compatible with the handler.
1939  */
1940 int input_register_handler(struct input_handler *handler)
1941 {
1942         struct input_dev *dev;
1943         int retval;
1944
1945         retval = mutex_lock_interruptible(&input_mutex);
1946         if (retval)
1947                 return retval;
1948
1949         INIT_LIST_HEAD(&handler->h_list);
1950
1951         if (handler->fops != NULL) {
1952                 if (input_table[handler->minor >> 5]) {
1953                         retval = -EBUSY;
1954                         goto out;
1955                 }
1956                 input_table[handler->minor >> 5] = handler;
1957         }
1958
1959         list_add_tail(&handler->node, &input_handler_list);
1960
1961         list_for_each_entry(dev, &input_dev_list, node)
1962                 input_attach_handler(dev, handler);
1963
1964         input_wakeup_procfs_readers();
1965
1966  out:
1967         mutex_unlock(&input_mutex);
1968         return retval;
1969 }
1970 EXPORT_SYMBOL(input_register_handler);
1971
1972 /**
1973  * input_unregister_handler - unregisters an input handler
1974  * @handler: handler to be unregistered
1975  *
1976  * This function disconnects a handler from its input devices and
1977  * removes it from lists of known handlers.
1978  */
1979 void input_unregister_handler(struct input_handler *handler)
1980 {
1981         struct input_handle *handle, *next;
1982
1983         mutex_lock(&input_mutex);
1984
1985         list_for_each_entry_safe(handle, next, &handler->h_list, h_node)
1986                 handler->disconnect(handle);
1987         WARN_ON(!list_empty(&handler->h_list));
1988
1989         list_del_init(&handler->node);
1990
1991         if (handler->fops != NULL)
1992                 input_table[handler->minor >> 5] = NULL;
1993
1994         input_wakeup_procfs_readers();
1995
1996         mutex_unlock(&input_mutex);
1997 }
1998 EXPORT_SYMBOL(input_unregister_handler);
1999
2000 /**
2001  * input_handler_for_each_handle - handle iterator
2002  * @handler: input handler to iterate
2003  * @data: data for the callback
2004  * @fn: function to be called for each handle
2005  *
2006  * Iterate over @bus's list of devices, and call @fn for each, passing
2007  * it @data and stop when @fn returns a non-zero value. The function is
2008  * using RCU to traverse the list and therefore may be usind in atonic
2009  * contexts. The @fn callback is invoked from RCU critical section and
2010  * thus must not sleep.
2011  */
2012 int input_handler_for_each_handle(struct input_handler *handler, void *data,
2013                                   int (*fn)(struct input_handle *, void *))
2014 {
2015         struct input_handle *handle;
2016         int retval = 0;
2017
2018         rcu_read_lock();
2019
2020         list_for_each_entry_rcu(handle, &handler->h_list, h_node) {
2021                 retval = fn(handle, data);
2022                 if (retval)
2023                         break;
2024         }
2025
2026         rcu_read_unlock();
2027
2028         return retval;
2029 }
2030 EXPORT_SYMBOL(input_handler_for_each_handle);
2031
2032 /**
2033  * input_register_handle - register a new input handle
2034  * @handle: handle to register
2035  *
2036  * This function puts a new input handle onto device's
2037  * and handler's lists so that events can flow through
2038  * it once it is opened using input_open_device().
2039  *
2040  * This function is supposed to be called from handler's
2041  * connect() method.
2042  */
2043 int input_register_handle(struct input_handle *handle)
2044 {
2045         struct input_handler *handler = handle->handler;
2046         struct input_dev *dev = handle->dev;
2047         int error;
2048
2049         /*
2050          * We take dev->mutex here to prevent race with
2051          * input_release_device().
2052          */
2053         error = mutex_lock_interruptible(&dev->mutex);
2054         if (error)
2055                 return error;
2056
2057         /*
2058          * Filters go to the head of the list, normal handlers
2059          * to the tail.
2060          */
2061         if (handler->filter)
2062                 list_add_rcu(&handle->d_node, &dev->h_list);
2063         else
2064                 list_add_tail_rcu(&handle->d_node, &dev->h_list);
2065
2066         mutex_unlock(&dev->mutex);
2067
2068         /*
2069          * Since we are supposed to be called from ->connect()
2070          * which is mutually exclusive with ->disconnect()
2071          * we can't be racing with input_unregister_handle()
2072          * and so separate lock is not needed here.
2073          */
2074         list_add_tail_rcu(&handle->h_node, &handler->h_list);
2075
2076         if (handler->start)
2077                 handler->start(handle);
2078
2079         return 0;
2080 }
2081 EXPORT_SYMBOL(input_register_handle);
2082
2083 /**
2084  * input_unregister_handle - unregister an input handle
2085  * @handle: handle to unregister
2086  *
2087  * This function removes input handle from device's
2088  * and handler's lists.
2089  *
2090  * This function is supposed to be called from handler's
2091  * disconnect() method.
2092  */
2093 void input_unregister_handle(struct input_handle *handle)
2094 {
2095         struct input_dev *dev = handle->dev;
2096
2097         list_del_rcu(&handle->h_node);
2098
2099         /*
2100          * Take dev->mutex to prevent race with input_release_device().
2101          */
2102         mutex_lock(&dev->mutex);
2103         list_del_rcu(&handle->d_node);
2104         mutex_unlock(&dev->mutex);
2105
2106         synchronize_rcu();
2107 }
2108 EXPORT_SYMBOL(input_unregister_handle);
2109
2110 static int input_open_file(struct inode *inode, struct file *file)
2111 {
2112         struct input_handler *handler;
2113         const struct file_operations *old_fops, *new_fops = NULL;
2114         int err;
2115
2116         err = mutex_lock_interruptible(&input_mutex);
2117         if (err)
2118                 return err;
2119
2120         /* No load-on-demand here? */
2121         handler = input_table[iminor(inode) >> 5];
2122         if (handler)
2123                 new_fops = fops_get(handler->fops);
2124
2125         mutex_unlock(&input_mutex);
2126
2127         /*
2128          * That's _really_ odd. Usually NULL ->open means "nothing special",
2129          * not "no device". Oh, well...
2130          */
2131         if (!new_fops || !new_fops->open) {
2132                 fops_put(new_fops);
2133                 err = -ENODEV;
2134                 goto out;
2135         }
2136
2137         old_fops = file->f_op;
2138         file->f_op = new_fops;
2139
2140         err = new_fops->open(inode, file);
2141         if (err) {
2142                 fops_put(file->f_op);
2143                 file->f_op = fops_get(old_fops);
2144         }
2145         fops_put(old_fops);
2146 out:
2147         return err;
2148 }
2149
2150 static const struct file_operations input_fops = {
2151         .owner = THIS_MODULE,
2152         .open = input_open_file,
2153         .llseek = noop_llseek,
2154 };
2155
2156 static int __init input_init(void)
2157 {
2158         int err;
2159
2160         err = class_register(&input_class);
2161         if (err) {
2162                 pr_err("unable to register input_dev class\n");
2163                 return err;
2164         }
2165
2166         err = input_proc_init();
2167         if (err)
2168                 goto fail1;
2169
2170         err = register_chrdev(INPUT_MAJOR, "input", &input_fops);
2171         if (err) {
2172                 pr_err("unable to register char major %d", INPUT_MAJOR);
2173                 goto fail2;
2174         }
2175
2176         return 0;
2177
2178  fail2: input_proc_exit();
2179  fail1: class_unregister(&input_class);
2180         return err;
2181 }
2182
2183 static void __exit input_exit(void)
2184 {
2185         input_proc_exit();
2186         unregister_chrdev(INPUT_MAJOR, "input");
2187         class_unregister(&input_class);
2188 }
2189
2190 subsys_initcall(input_init);
2191 module_exit(input_exit);