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