drivers/input/input.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * The input core
   4  *
   5  * Copyright (c) 1999-2002 Vojtech Pavlik
   6  */
   7
   8
   9 #define pr_fmt(fmt) KBUILD_BASENAME ": " fmt
  10
  11 #include <linux/init.h>
  12 #include <linux/types.h>
  13 #include <linux/idr.h>
  14 #include <linux/input/mt.h>
  15 #include <linux/module.h>
  16 #include <linux/slab.h>
  17 #include <linux/random.h>
  18 #include <linux/major.h>
  19 #include <linux/proc_fs.h>
  20 #include <linux/sched.h>
  21 #include <linux/seq_file.h>
  22 #include <linux/poll.h>
  23 #include <linux/device.h>
  24 #include <linux/mutex.h>
  25 #include <linux/rcupdate.h>
  26 #include "input-compat.h"
  27 #include "input-poller.h"
  28
  29 MODULE_AUTHOR("Vojtech Pavlik <vojtech@suse.cz>");
  30 MODULE_DESCRIPTION("Input core");
  31 MODULE_LICENSE("GPL");
  32
  33 #define INPUT_MAX_CHAR_DEVICES          1024
  34 #define INPUT_FIRST_DYNAMIC_DEV         256
  35 static DEFINE_IDA(input_ida);
  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 const struct input_value input_value_sync = { EV_SYN, SYN_REPORT, 1 };
  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 static void input_start_autorepeat(struct input_dev *dev, int code)
  73 {
  74         if (test_bit(EV_REP, dev->evbit) &&
  75             dev->rep[REP_PERIOD] && dev->rep[REP_DELAY] &&
  76             dev->timer.function) {
  77                 dev->repeat_key = code;
  78                 mod_timer(&dev->timer,
  79                           jiffies + msecs_to_jiffies(dev->rep[REP_DELAY]));
  80         }
  81 }
  82
  83 static void input_stop_autorepeat(struct input_dev *dev)
  84 {
  85         del_timer(&dev->timer);
  86 }
  87
  88 /*
  89  * Pass event first through all filters and then, if event has not been
  90  * filtered out, through all open handles. This function is called with
  91  * dev->event_lock held and interrupts disabled.
  92  */
  93 static unsigned int input_to_handler(struct input_handle *handle,
  94                         struct input_value *vals, unsigned int count)
  95 {
  96         struct input_handler *handler = handle->handler;
  97         struct input_value *end = vals;
  98         struct input_value *v;
  99
 100         if (handler->filter) {
 101                 for (v = vals; v != vals + count; v++) {
 102                         if (handler->filter(handle, v->type, v->code, v->value))
 103                                 continue;
 104                         if (end != v)
 105                                 *end = *v;
 106                         end++;
 107                 }
 108                 count = end - vals;
 109         }
 110
 111         if (!count)
 112                 return 0;
 113
 114         if (handler->events)
 115                 handler->events(handle, vals, count);
 116         else if (handler->event)
 117                 for (v = vals; v != vals + count; v++)
 118                         handler->event(handle, v->type, v->code, v->value);
 119
 120         return count;
 121 }
 122
 123 /*
 124  * Pass values first through all filters and then, if event has not been
 125  * filtered out, through all open handles. This function is called with
 126  * dev->event_lock held and interrupts disabled.
 127  */
 128 static void input_pass_values(struct input_dev *dev,
 129                               struct input_value *vals, unsigned int count)
 130 {
 131         struct input_handle *handle;
 132         struct input_value *v;
 133
 134         if (!count)
 135                 return;
 136
 137         rcu_read_lock();
 138
 139         handle = rcu_dereference(dev->grab);
 140         if (handle) {
 141                 count = input_to_handler(handle, vals, count);
 142         } else {
 143                 list_for_each_entry_rcu(handle, &dev->h_list, d_node)
 144                         if (handle->open) {
 145                                 count = input_to_handler(handle, vals, count);
 146                                 if (!count)
 147                                         break;
 148                         }
 149         }
 150
 151         rcu_read_unlock();
 152
 153         /* trigger auto repeat for key events */
 154         if (test_bit(EV_REP, dev->evbit) && test_bit(EV_KEY, dev->evbit)) {
 155                 for (v = vals; v != vals + count; v++) {
 156                         if (v->type == EV_KEY && v->value != 2) {
 157                                 if (v->value)
 158                                         input_start_autorepeat(dev, v->code);
 159                                 else
 160                                         input_stop_autorepeat(dev);
 161                         }
 162                 }
 163         }
 164 }
 165
 166 static void input_pass_event(struct input_dev *dev,
 167                              unsigned int type, unsigned int code, int value)
 168 {
 169         struct input_value vals[] = { { type, code, value } };
 170
 171         input_pass_values(dev, vals, ARRAY_SIZE(vals));
 172 }
 173
 174 /*
 175  * Generate software autorepeat event. Note that we take
 176  * dev->event_lock here to avoid racing with input_event
 177  * which may cause keys get "stuck".
 178  */
 179 static void input_repeat_key(struct timer_list *t)
 180 {
 181         struct input_dev *dev = from_timer(dev, t, timer);
 182         unsigned long flags;
 183
 184         spin_lock_irqsave(&dev->event_lock, flags);
 185
 186         if (test_bit(dev->repeat_key, dev->key) &&
 187             is_event_supported(dev->repeat_key, dev->keybit, KEY_MAX)) {
 188                 struct input_value vals[] =  {
 189                         { EV_KEY, dev->repeat_key, 2 },
 190                         input_value_sync
 191                 };
 192
 193                 input_pass_values(dev, vals, ARRAY_SIZE(vals));
 194
 195                 if (dev->rep[REP_PERIOD])
 196                         mod_timer(&dev->timer, jiffies +
 197                                         msecs_to_jiffies(dev->rep[REP_PERIOD]));
 198         }
 199
 200         spin_unlock_irqrestore(&dev->event_lock, flags);
 201 }
 202
 203 #define INPUT_IGNORE_EVENT      0
 204 #define INPUT_PASS_TO_HANDLERS  1
 205 #define INPUT_PASS_TO_DEVICE    2
 206 #define INPUT_SLOT              4
 207 #define INPUT_FLUSH             8
 208 #define INPUT_PASS_TO_ALL       (INPUT_PASS_TO_HANDLERS | INPUT_PASS_TO_DEVICE)
 209
 210 static int input_handle_abs_event(struct input_dev *dev,
 211                                   unsigned int code, int *pval)
 212 {
 213         struct input_mt *mt = dev->mt;
 214         bool is_mt_event;
 215         int *pold;
 216
 217         if (code == ABS_MT_SLOT) {
 218                 /*
 219                  * "Stage" the event; we'll flush it later, when we
 220                  * get actual touch data.
 221                  */
 222                 if (mt && *pval >= 0 && *pval < mt->num_slots)
 223                         mt->slot = *pval;
 224
 225                 return INPUT_IGNORE_EVENT;
 226         }
 227
 228         is_mt_event = input_is_mt_value(code);
 229
 230         if (!is_mt_event) {
 231                 pold = &dev->absinfo[code].value;
 232         } else if (mt) {
 233                 pold = &mt->slots[mt->slot].abs[code - ABS_MT_FIRST];
 234         } else {
 235                 /*
 236                  * Bypass filtering for multi-touch events when
 237                  * not employing slots.
 238                  */
 239                 pold = NULL;
 240         }
 241
 242         if (pold) {
 243                 *pval = input_defuzz_abs_event(*pval, *pold,
 244                                                 dev->absinfo[code].fuzz);
 245                 if (*pold == *pval)
 246                         return INPUT_IGNORE_EVENT;
 247
 248                 *pold = *pval;
 249         }
 250
 251         /* Flush pending "slot" event */
 252         if (is_mt_event && mt && mt->slot != input_abs_get_val(dev, ABS_MT_SLOT)) {
 253                 input_abs_set_val(dev, ABS_MT_SLOT, mt->slot);
 254                 return INPUT_PASS_TO_HANDLERS | INPUT_SLOT;
 255         }
 256
 257         return INPUT_PASS_TO_HANDLERS;
 258 }
 259
 260 static int input_get_disposition(struct input_dev *dev,
 261                           unsigned int type, unsigned int code, int *pval)
 262 {
 263         int disposition = INPUT_IGNORE_EVENT;
 264         int value = *pval;
 265
 266         switch (type) {
 267
 268         case EV_SYN:
 269                 switch (code) {
 270                 case SYN_CONFIG:
 271                         disposition = INPUT_PASS_TO_ALL;
 272                         break;
 273
 274                 case SYN_REPORT:
 275                         disposition = INPUT_PASS_TO_HANDLERS | INPUT_FLUSH;
 276                         break;
 277                 case SYN_MT_REPORT:
 278                         disposition = INPUT_PASS_TO_HANDLERS;
 279                         break;
 280                 }
 281                 break;
 282
 283         case EV_KEY:
 284                 if (is_event_supported(code, dev->keybit, KEY_MAX)) {
 285
 286                         /* auto-repeat bypasses state updates */
 287                         if (value == 2) {
 288                                 disposition = INPUT_PASS_TO_HANDLERS;
 289                                 break;
 290                         }
 291
 292                         if (!!test_bit(code, dev->key) != !!value) {
 293
 294                                 __change_bit(code, dev->key);
 295                                 disposition = INPUT_PASS_TO_HANDLERS;
 296                         }
 297                 }
 298                 break;
 299
 300         case EV_SW:
 301                 if (is_event_supported(code, dev->swbit, SW_MAX) &&
 302                     !!test_bit(code, dev->sw) != !!value) {
 303
 304                         __change_bit(code, dev->sw);
 305                         disposition = INPUT_PASS_TO_HANDLERS;
 306                 }
 307                 break;
 308
 309         case EV_ABS:
 310                 if (is_event_supported(code, dev->absbit, ABS_MAX))
 311                         disposition = input_handle_abs_event(dev, code, &value);
 312
 313                 break;
 314
 315         case EV_REL:
 316                 if (is_event_supported(code, dev->relbit, REL_MAX) && value)
 317                         disposition = INPUT_PASS_TO_HANDLERS;
 318
 319                 break;
 320
 321         case EV_MSC:
 322                 if (is_event_supported(code, dev->mscbit, MSC_MAX))
 323                         disposition = INPUT_PASS_TO_ALL;
 324
 325                 break;
 326
 327         case EV_LED:
 328                 if (is_event_supported(code, dev->ledbit, LED_MAX) &&
 329                     !!test_bit(code, dev->led) != !!value) {
 330
 331                         __change_bit(code, dev->led);
 332                         disposition = INPUT_PASS_TO_ALL;
 333                 }
 334                 break;
 335
 336         case EV_SND:
 337                 if (is_event_supported(code, dev->sndbit, SND_MAX)) {
 338
 339                         if (!!test_bit(code, dev->snd) != !!value)
 340                                 __change_bit(code, dev->snd);
 341                         disposition = INPUT_PASS_TO_ALL;
 342                 }
 343                 break;
 344
 345         case EV_REP:
 346                 if (code <= REP_MAX && value >= 0 && dev->rep[code] != value) {
 347                         dev->rep[code] = value;
 348                         disposition = INPUT_PASS_TO_ALL;
 349                 }
 350                 break;
 351
 352         case EV_FF:
 353                 if (value >= 0)
 354                         disposition = INPUT_PASS_TO_ALL;
 355                 break;
 356
 357         case EV_PWR:
 358                 disposition = INPUT_PASS_TO_ALL;
 359                 break;
 360         }
 361
 362         *pval = value;
 363         return disposition;
 364 }
 365
 366 static void input_handle_event(struct input_dev *dev,
 367                                unsigned int type, unsigned int code, int value)
 368 {
 369         int disposition = input_get_disposition(dev, type, code, &value);
 370
 371         if (disposition != INPUT_IGNORE_EVENT && type != EV_SYN)
 372                 add_input_randomness(type, code, value);
 373
 374         if ((disposition & INPUT_PASS_TO_DEVICE) && dev->event)
 375                 dev->event(dev, type, code, value);
 376
 377         if (!dev->vals)
 378                 return;
 379
 380         if (disposition & INPUT_PASS_TO_HANDLERS) {
 381                 struct input_value *v;
 382
 383                 if (disposition & INPUT_SLOT) {
 384                         v = &dev->vals[dev->num_vals++];
 385                         v->type = EV_ABS;
 386                         v->code = ABS_MT_SLOT;
 387                         v->value = dev->mt->slot;
 388                 }
 389
 390                 v = &dev->vals[dev->num_vals++];
 391                 v->type = type;
 392                 v->code = code;
 393                 v->value = value;
 394         }
 395
 396         if (disposition & INPUT_FLUSH) {
 397                 if (dev->num_vals >= 2)
 398                         input_pass_values(dev, dev->vals, dev->num_vals);
 399                 dev->num_vals = 0;
 400                 /*
 401                  * Reset the timestamp on flush so we won't end up
 402                  * with a stale one. Note we only need to reset the
 403                  * monolithic one as we use its presence when deciding
 404                  * whether to generate a synthetic timestamp.
 405                  */
 406                 dev->timestamp[INPUT_CLK_MONO] = ktime_set(0, 0);
 407         } else if (dev->num_vals >= dev->max_vals - 2) {
 408                 dev->vals[dev->num_vals++] = input_value_sync;
 409                 input_pass_values(dev, dev->vals, dev->num_vals);
 410                 dev->num_vals = 0;
 411         }
 412
 413 }
 414
 415 /**
 416  * input_event() - report new input event
 417  * @dev: device that generated the event
 418  * @type: type of the event
 419  * @code: event code
 420  * @value: value of the event
 421  *
 422  * This function should be used by drivers implementing various input
 423  * devices to report input events. See also input_inject_event().
 424  *
 425  * NOTE: input_event() may be safely used right after input device was
 426  * allocated with input_allocate_device(), even before it is registered
 427  * with input_register_device(), but the event will not reach any of the
 428  * input handlers. Such early invocation of input_event() may be used
 429  * to 'seed' initial state of a switch or initial position of absolute
 430  * axis, etc.
 431  */
 432 void input_event(struct input_dev *dev,
 433                  unsigned int type, unsigned int code, int value)
 434 {
 435         unsigned long flags;
 436
 437         if (is_event_supported(type, dev->evbit, EV_MAX)) {
 438
 439                 spin_lock_irqsave(&dev->event_lock, flags);
 440                 input_handle_event(dev, type, code, value);
 441                 spin_unlock_irqrestore(&dev->event_lock, flags);
 442         }
 443 }
 444 EXPORT_SYMBOL(input_event);
 445
 446 /**
 447  * input_inject_event() - send input event from input handler
 448  * @handle: input handle to send event through
 449  * @type: type of the event
 450  * @code: event code
 451  * @value: value of the event
 452  *
 453  * Similar to input_event() but will ignore event if device is
 454  * "grabbed" and handle injecting event is not the one that owns
 455  * the device.
 456  */
 457 void input_inject_event(struct input_handle *handle,
 458                         unsigned int type, unsigned int code, int value)
 459 {
 460         struct input_dev *dev = handle->dev;
 461         struct input_handle *grab;
 462         unsigned long flags;
 463
 464         if (is_event_supported(type, dev->evbit, EV_MAX)) {
 465                 spin_lock_irqsave(&dev->event_lock, flags);
 466
 467                 rcu_read_lock();
 468                 grab = rcu_dereference(dev->grab);
 469                 if (!grab || grab == handle)
 470                         input_handle_event(dev, type, code, value);
 471                 rcu_read_unlock();
 472
 473                 spin_unlock_irqrestore(&dev->event_lock, flags);
 474         }
 475 }
 476 EXPORT_SYMBOL(input_inject_event);
 477
 478 /**
 479  * input_alloc_absinfo - allocates array of input_absinfo structs
 480  * @dev: the input device emitting absolute events
 481  *
 482  * If the absinfo struct the caller asked for is already allocated, this
 483  * functions will not do anything.
 484  */
 485 void input_alloc_absinfo(struct input_dev *dev)
 486 {
 487         if (dev->absinfo)
 488                 return;
 489
 490         dev->absinfo = kcalloc(ABS_CNT, sizeof(*dev->absinfo), GFP_KERNEL);
 491         if (!dev->absinfo) {
 492                 dev_err(dev->dev.parent ?: &dev->dev,
 493                         "%s: unable to allocate memory\n", __func__);
 494                 /*
 495                  * We will handle this allocation failure in
 496                  * input_register_device() when we refuse to register input
 497                  * device with ABS bits but without absinfo.
 498                  */
 499         }
 500 }
 501 EXPORT_SYMBOL(input_alloc_absinfo);
 502
 503 void input_set_abs_params(struct input_dev *dev, unsigned int axis,
 504                           int min, int max, int fuzz, int flat)
 505 {
 506         struct input_absinfo *absinfo;
 507
 508         input_alloc_absinfo(dev);
 509         if (!dev->absinfo)
 510                 return;
 511
 512         absinfo = &dev->absinfo[axis];
 513         absinfo->minimum = min;
 514         absinfo->maximum = max;
 515         absinfo->fuzz = fuzz;
 516         absinfo->flat = flat;
 517
 518         __set_bit(EV_ABS, dev->evbit);
 519         __set_bit(axis, dev->absbit);
 520 }
 521 EXPORT_SYMBOL(input_set_abs_params);
 522
 523
 524 /**
 525  * input_grab_device - grabs device for exclusive use
 526  * @handle: input handle that wants to own the device
 527  *
 528  * When a device is grabbed by an input handle all events generated by
 529  * the device are delivered only to this handle. Also events injected
 530  * by other input handles are ignored while device is grabbed.
 531  */
 532 int input_grab_device(struct input_handle *handle)
 533 {
 534         struct input_dev *dev = handle->dev;
 535         int retval;
 536
 537         retval = mutex_lock_interruptible(&dev->mutex);
 538         if (retval)
 539                 return retval;
 540
 541         if (dev->grab) {
 542                 retval = -EBUSY;
 543                 goto out;
 544         }
 545
 546         rcu_assign_pointer(dev->grab, handle);
 547
 548  out:
 549         mutex_unlock(&dev->mutex);
 550         return retval;
 551 }
 552 EXPORT_SYMBOL(input_grab_device);
 553
 554 static void __input_release_device(struct input_handle *handle)
 555 {
 556         struct input_dev *dev = handle->dev;
 557         struct input_handle *grabber;
 558
 559         grabber = rcu_dereference_protected(dev->grab,
 560                                             lockdep_is_held(&dev->mutex));
 561         if (grabber == handle) {
 562                 rcu_assign_pointer(dev->grab, NULL);
 563                 /* Make sure input_pass_event() notices that grab is gone */
 564                 synchronize_rcu();
 565
 566                 list_for_each_entry(handle, &dev->h_list, d_node)
 567                         if (handle->open && handle->handler->start)
 568                                 handle->handler->start(handle);
 569         }
 570 }
 571
 572 /**
 573  * input_release_device - release previously grabbed device
 574  * @handle: input handle that owns the device
 575  *
 576  * Releases previously grabbed device so that other input handles can
 577  * start receiving input events. Upon release all handlers attached
 578  * to the device have their start() method called so they have a change
 579  * to synchronize device state with the rest of the system.
 580  */
 581 void input_release_device(struct input_handle *handle)
 582 {
 583         struct input_dev *dev = handle->dev;
 584
 585         mutex_lock(&dev->mutex);
 586         __input_release_device(handle);
 587         mutex_unlock(&dev->mutex);
 588 }
 589 EXPORT_SYMBOL(input_release_device);
 590
 591 /**
 592  * input_open_device - open input device
 593  * @handle: handle through which device is being accessed
 594  *
 595  * This function should be called by input handlers when they
 596  * want to start receive events from given input device.
 597  */
 598 int input_open_device(struct input_handle *handle)
 599 {
 600         struct input_dev *dev = handle->dev;
 601         int retval;
 602
 603         retval = mutex_lock_interruptible(&dev->mutex);
 604         if (retval)
 605                 return retval;
 606
 607         if (dev->going_away) {
 608                 retval = -ENODEV;
 609                 goto out;
 610         }
 611
 612         handle->open++;
 613
 614         if (dev->users++) {
 615                 /*
 616                  * Device is already opened, so we can exit immediately and
 617                  * report success.
 618                  */
 619                 goto out;
 620         }
 621
 622         if (dev->open) {
 623                 retval = dev->open(dev);
 624                 if (retval) {
 625                         dev->users--;
 626                         handle->open--;
 627                         /*
 628                          * Make sure we are not delivering any more events
 629                          * through this handle
 630                          */
 631                         synchronize_rcu();
 632                         goto out;
 633                 }
 634         }
 635
 636         if (dev->poller)
 637                 input_dev_poller_start(dev->poller);
 638
 639  out:
 640         mutex_unlock(&dev->mutex);
 641         return retval;
 642 }
 643 EXPORT_SYMBOL(input_open_device);
 644
 645 int input_flush_device(struct input_handle *handle, struct file *file)
 646 {
 647         struct input_dev *dev = handle->dev;
 648         int retval;
 649
 650         retval = mutex_lock_interruptible(&dev->mutex);
 651         if (retval)
 652                 return retval;
 653
 654         if (dev->flush)
 655                 retval = dev->flush(dev, file);
 656
 657         mutex_unlock(&dev->mutex);
 658         return retval;
 659 }
 660 EXPORT_SYMBOL(input_flush_device);
 661
 662 /**
 663  * input_close_device - close input device
 664  * @handle: handle through which device is being accessed
 665  *
 666  * This function should be called by input handlers when they
 667  * want to stop receive events from given input device.
 668  */
 669 void input_close_device(struct input_handle *handle)
 670 {
 671         struct input_dev *dev = handle->dev;
 672
 673         mutex_lock(&dev->mutex);
 674
 675         __input_release_device(handle);
 676
 677         if (!--dev->users) {
 678                 if (dev->poller)
 679                         input_dev_poller_stop(dev->poller);
 680
 681                 if (dev->close)
 682                         dev->close(dev);
 683         }
 684
 685         if (!--handle->open) {
 686                 /*
 687                  * synchronize_rcu() makes sure that input_pass_event()
 688                  * completed and that no more input events are delivered
 689                  * through this handle
 690                  */
 691                 synchronize_rcu();
 692         }
 693
 694         mutex_unlock(&dev->mutex);
 695 }
 696 EXPORT_SYMBOL(input_close_device);
 697
 698 /*
 699  * Simulate keyup events for all keys that are marked as pressed.
 700  * The function must be called with dev->event_lock held.
 701  */
 702 static void input_dev_release_keys(struct input_dev *dev)
 703 {
 704         bool need_sync = false;
 705         int code;
 706
 707         if (is_event_supported(EV_KEY, dev->evbit, EV_MAX)) {
 708                 for_each_set_bit(code, dev->key, KEY_CNT) {
 709                         input_pass_event(dev, EV_KEY, code, 0);
 710                         need_sync = true;
 711                 }
 712
 713                 if (need_sync)
 714                         input_pass_event(dev, EV_SYN, SYN_REPORT, 1);
 715
 716                 memset(dev->key, 0, sizeof(dev->key));
 717         }
 718 }
 719
 720 /*
 721  * Prepare device for unregistering
 722  */
 723 static void input_disconnect_device(struct input_dev *dev)
 724 {
 725         struct input_handle *handle;
 726
 727         /*
 728          * Mark device as going away. Note that we take dev->mutex here
 729          * not to protect access to dev->going_away but rather to ensure
 730          * that there are no threads in the middle of input_open_device()
 731          */
 732         mutex_lock(&dev->mutex);
 733         dev->going_away = true;
 734         mutex_unlock(&dev->mutex);
 735
 736         spin_lock_irq(&dev->event_lock);
 737
 738         /*
 739          * Simulate keyup events for all pressed keys so that handlers
 740          * are not left with "stuck" keys. The driver may continue
 741          * generate events even after we done here but they will not
 742          * reach any handlers.
 743          */
 744         input_dev_release_keys(dev);
 745
 746         list_for_each_entry(handle, &dev->h_list, d_node)
 747                 handle->open = 0;
 748
 749         spin_unlock_irq(&dev->event_lock);
 750 }
 751
 752 /**
 753  * input_scancode_to_scalar() - converts scancode in &struct input_keymap_entry
 754  * @ke: keymap entry containing scancode to be converted.
 755  * @scancode: pointer to the location where converted scancode should
 756  *      be stored.
 757  *
 758  * This function is used to convert scancode stored in &struct keymap_entry
 759  * into scalar form understood by legacy keymap handling methods. These
 760  * methods expect scancodes to be represented as 'unsigned int'.
 761  */
 762 int input_scancode_to_scalar(const struct input_keymap_entry *ke,
 763                              unsigned int *scancode)
 764 {
 765         switch (ke->len) {
 766         case 1:
 767                 *scancode = *((u8 *)ke->scancode);
 768                 break;
 769
 770         case 2:
 771                 *scancode = *((u16 *)ke->scancode);
 772                 break;
 773
 774         case 4:
 775                 *scancode = *((u32 *)ke->scancode);
 776                 break;
 777
 778         default:
 779                 return -EINVAL;
 780         }
 781
 782         return 0;
 783 }
 784 EXPORT_SYMBOL(input_scancode_to_scalar);
 785
 786 /*
 787  * Those routines handle the default case where no [gs]etkeycode() is
 788  * defined. In this case, an array indexed by the scancode is used.
 789  */
 790
 791 static unsigned int input_fetch_keycode(struct input_dev *dev,
 792                                         unsigned int index)
 793 {
 794         switch (dev->keycodesize) {
 795         case 1:
 796                 return ((u8 *)dev->keycode)[index];
 797
 798         case 2:
 799                 return ((u16 *)dev->keycode)[index];
 800
 801         default:
 802                 return ((u32 *)dev->keycode)[index];
 803         }
 804 }
 805
 806 static int input_default_getkeycode(struct input_dev *dev,
 807                                     struct input_keymap_entry *ke)
 808 {
 809         unsigned int index;
 810         int error;
 811
 812         if (!dev->keycodesize)
 813                 return -EINVAL;
 814
 815         if (ke->flags & INPUT_KEYMAP_BY_INDEX)
 816                 index = ke->index;
 817         else {
 818                 error = input_scancode_to_scalar(ke, &index);
 819                 if (error)
 820                         return error;
 821         }
 822
 823         if (index >= dev->keycodemax)
 824                 return -EINVAL;
 825
 826         ke->keycode = input_fetch_keycode(dev, index);
 827         ke->index = index;
 828         ke->len = sizeof(index);
 829         memcpy(ke->scancode, &index, sizeof(index));
 830
 831         return 0;
 832 }
 833
 834 static int input_default_setkeycode(struct input_dev *dev,
 835                                     const struct input_keymap_entry *ke,
 836                                     unsigned int *old_keycode)
 837 {
 838         unsigned int index;
 839         int error;
 840         int i;
 841
 842         if (!dev->keycodesize)
 843                 return -EINVAL;
 844
 845         if (ke->flags & INPUT_KEYMAP_BY_INDEX) {
 846                 index = ke->index;
 847         } else {
 848                 error = input_scancode_to_scalar(ke, &index);
 849                 if (error)
 850                         return error;
 851         }
 852
 853         if (index >= dev->keycodemax)
 854                 return -EINVAL;
 855
 856         if (dev->keycodesize < sizeof(ke->keycode) &&
 857                         (ke->keycode >> (dev->keycodesize * 8)))
 858                 return -EINVAL;
 859
 860         switch (dev->keycodesize) {
 861                 case 1: {
 862                         u8 *k = (u8 *)dev->keycode;
 863                         *old_keycode = k[index];
 864                         k[index] = ke->keycode;
 865                         break;
 866                 }
 867                 case 2: {
 868                         u16 *k = (u16 *)dev->keycode;
 869                         *old_keycode = k[index];
 870                         k[index] = ke->keycode;
 871                         break;
 872                 }
 873                 default: {
 874                         u32 *k = (u32 *)dev->keycode;
 875                         *old_keycode = k[index];
 876                         k[index] = ke->keycode;
 877                         break;
 878                 }
 879         }
 880
 881         if (*old_keycode <= KEY_MAX) {
 882                 __clear_bit(*old_keycode, dev->keybit);
 883                 for (i = 0; i < dev->keycodemax; i++) {
 884                         if (input_fetch_keycode(dev, i) == *old_keycode) {
 885                                 __set_bit(*old_keycode, dev->keybit);
 886                                 /* Setting the bit twice is useless, so break */
 887                                 break;
 888                         }
 889                 }
 890         }
 891
 892         __set_bit(ke->keycode, dev->keybit);
 893         return 0;
 894 }
 895
 896 /**
 897  * input_get_keycode - retrieve keycode currently mapped to a given scancode
 898  * @dev: input device which keymap is being queried
 899  * @ke: keymap entry
 900  *
 901  * This function should be called by anyone interested in retrieving current
 902  * keymap. Presently evdev handlers use it.
 903  */
 904 int input_get_keycode(struct input_dev *dev, struct input_keymap_entry *ke)
 905 {
 906         unsigned long flags;
 907         int retval;
 908
 909         spin_lock_irqsave(&dev->event_lock, flags);
 910         retval = dev->getkeycode(dev, ke);
 911         spin_unlock_irqrestore(&dev->event_lock, flags);
 912
 913         return retval;
 914 }
 915 EXPORT_SYMBOL(input_get_keycode);
 916
 917 /**
 918  * input_set_keycode - attribute a keycode to a given scancode
 919  * @dev: input device which keymap is being updated
 920  * @ke: new keymap entry
 921  *
 922  * This function should be called by anyone needing to update current
 923  * keymap. Presently keyboard and evdev handlers use it.
 924  */
 925 int input_set_keycode(struct input_dev *dev,
 926                       const struct input_keymap_entry *ke)
 927 {
 928         unsigned long flags;
 929         unsigned int old_keycode;
 930         int retval;
 931
 932         if (ke->keycode > KEY_MAX)
 933                 return -EINVAL;
 934
 935         spin_lock_irqsave(&dev->event_lock, flags);
 936
 937         retval = dev->setkeycode(dev, ke, &old_keycode);
 938         if (retval)
 939                 goto out;
 940
 941         /* Make sure KEY_RESERVED did not get enabled. */
 942         __clear_bit(KEY_RESERVED, dev->keybit);
 943
 944         /*
 945          * Simulate keyup event if keycode is not present
 946          * in the keymap anymore
 947          */
 948         if (old_keycode > KEY_MAX) {
 949                 dev_warn(dev->dev.parent ?: &dev->dev,
 950                          "%s: got too big old keycode %#x\n",
 951                          __func__, old_keycode);
 952         } else if (test_bit(EV_KEY, dev->evbit) &&
 953                    !is_event_supported(old_keycode, dev->keybit, KEY_MAX) &&
 954                    __test_and_clear_bit(old_keycode, dev->key)) {
 955                 struct input_value vals[] =  {
 956                         { EV_KEY, old_keycode, 0 },
 957                         input_value_sync
 958                 };
 959
 960                 input_pass_values(dev, vals, ARRAY_SIZE(vals));
 961         }
 962
 963  out:
 964         spin_unlock_irqrestore(&dev->event_lock, flags);
 965
 966         return retval;
 967 }
 968 EXPORT_SYMBOL(input_set_keycode);
 969
 970 bool input_match_device_id(const struct input_dev *dev,
 971                            const struct input_device_id *id)
 972 {
 973         if (id->flags & INPUT_DEVICE_ID_MATCH_BUS)
 974                 if (id->bustype != dev->id.bustype)
 975                         return false;
 976
 977         if (id->flags & INPUT_DEVICE_ID_MATCH_VENDOR)
 978                 if (id->vendor != dev->id.vendor)
 979                         return false;
 980
 981         if (id->flags & INPUT_DEVICE_ID_MATCH_PRODUCT)
 982                 if (id->product != dev->id.product)
 983                         return false;
 984
 985         if (id->flags & INPUT_DEVICE_ID_MATCH_VERSION)
 986                 if (id->version != dev->id.version)
 987                         return false;
 988
 989         if (!bitmap_subset(id->evbit, dev->evbit, EV_MAX) ||
 990             !bitmap_subset(id->keybit, dev->keybit, KEY_MAX) ||
 991             !bitmap_subset(id->relbit, dev->relbit, REL_MAX) ||
 992             !bitmap_subset(id->absbit, dev->absbit, ABS_MAX) ||
 993             !bitmap_subset(id->mscbit, dev->mscbit, MSC_MAX) ||
 994             !bitmap_subset(id->ledbit, dev->ledbit, LED_MAX) ||
 995             !bitmap_subset(id->sndbit, dev->sndbit, SND_MAX) ||
 996             !bitmap_subset(id->ffbit, dev->ffbit, FF_MAX) ||
 997             !bitmap_subset(id->swbit, dev->swbit, SW_MAX) ||
 998             !bitmap_subset(id->propbit, dev->propbit, INPUT_PROP_MAX)) {
 999                 return false;
1000         }
1001
1002         return true;
1003 }
1004 EXPORT_SYMBOL(input_match_device_id);
1005
1006 static const struct input_device_id *input_match_device(struct input_handler *handler,
1007                                                         struct input_dev *dev)
1008 {
1009         const struct input_device_id *id;
1010
1011         for (id = handler->id_table; id->flags || id->driver_info; id++) {
1012                 if (input_match_device_id(dev, id) &&
1013                     (!handler->match || handler->match(handler, dev))) {
1014                         return id;
1015                 }
1016         }
1017
1018         return NULL;
1019 }
1020
1021 static int input_attach_handler(struct input_dev *dev, struct input_handler *handler)
1022 {
1023         const struct input_device_id *id;
1024         int error;
1025
1026         id = input_match_device(handler, dev);
1027         if (!id)
1028                 return -ENODEV;
1029
1030         error = handler->connect(handler, dev, id);
1031         if (error && error != -ENODEV)
1032                 pr_err("failed to attach handler %s to device %s, error: %d\n",
1033                        handler->name, kobject_name(&dev->dev.kobj), error);
1034
1035         return error;
1036 }
1037
1038 #ifdef CONFIG_COMPAT
1039
1040 static int input_bits_to_string(char *buf, int buf_size,
1041                                 unsigned long bits, bool skip_empty)
1042 {
1043         int len = 0;
1044
1045         if (in_compat_syscall()) {
1046                 u32 dword = bits >> 32;
1047                 if (dword || !skip_empty)
1048                         len += snprintf(buf, buf_size, "%x ", dword);
1049
1050                 dword = bits & 0xffffffffUL;
1051                 if (dword || !skip_empty || len)
1052                         len += snprintf(buf + len, max(buf_size - len, 0),
1053                                         "%x", dword);
1054         } else {
1055                 if (bits || !skip_empty)
1056                         len += snprintf(buf, buf_size, "%lx", bits);
1057         }
1058
1059         return len;
1060 }
1061
1062 #else /* !CONFIG_COMPAT */
1063
1064 static int input_bits_to_string(char *buf, int buf_size,
1065                                 unsigned long bits, bool skip_empty)
1066 {
1067         return bits || !skip_empty ?
1068                 snprintf(buf, buf_size, "%lx", bits) : 0;
1069 }
1070
1071 #endif
1072
1073 #ifdef CONFIG_PROC_FS
1074
1075 static struct proc_dir_entry *proc_bus_input_dir;
1076 static DECLARE_WAIT_QUEUE_HEAD(input_devices_poll_wait);
1077 static int input_devices_state;
1078
1079 static inline void input_wakeup_procfs_readers(void)
1080 {
1081         input_devices_state++;
1082         wake_up(&input_devices_poll_wait);
1083 }
1084
1085 static __poll_t input_proc_devices_poll(struct file *file, poll_table *wait)
1086 {
1087         poll_wait(file, &input_devices_poll_wait, wait);
1088         if (file->f_version != input_devices_state) {
1089                 file->f_version = input_devices_state;
1090                 return EPOLLIN | EPOLLRDNORM;
1091         }
1092
1093         return 0;
1094 }
1095
1096 union input_seq_state {
1097         struct {
1098                 unsigned short pos;
1099                 bool mutex_acquired;
1100         };
1101         void *p;
1102 };
1103
1104 static void *input_devices_seq_start(struct seq_file *seq, loff_t *pos)
1105 {
1106         union input_seq_state *state = (union input_seq_state *)&seq->private;
1107         int error;
1108
1109         /* We need to fit into seq->private pointer */
1110         BUILD_BUG_ON(sizeof(union input_seq_state) != sizeof(seq->private));
1111
1112         error = mutex_lock_interruptible(&input_mutex);
1113         if (error) {
1114                 state->mutex_acquired = false;
1115                 return ERR_PTR(error);
1116         }
1117
1118         state->mutex_acquired = true;
1119
1120         return seq_list_start(&input_dev_list, *pos);
1121 }
1122
1123 static void *input_devices_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1124 {
1125         return seq_list_next(v, &input_dev_list, pos);
1126 }
1127
1128 static void input_seq_stop(struct seq_file *seq, void *v)
1129 {
1130         union input_seq_state *state = (union input_seq_state *)&seq->private;
1131
1132         if (state->mutex_acquired)
1133                 mutex_unlock(&input_mutex);
1134 }
1135
1136 static void input_seq_print_bitmap(struct seq_file *seq, const char *name,
1137                                    unsigned long *bitmap, int max)
1138 {
1139         int i;
1140         bool skip_empty = true;
1141         char buf[18];
1142
1143         seq_printf(seq, "B: %s=", name);
1144
1145         for (i = BITS_TO_LONGS(max) - 1; i >= 0; i--) {
1146                 if (input_bits_to_string(buf, sizeof(buf),
1147                                          bitmap[i], skip_empty)) {
1148                         skip_empty = false;
1149                         seq_printf(seq, "%s%s", buf, i > 0 ? " " : "");
1150                 }
1151         }
1152
1153         /*
1154          * If no output was produced print a single 0.
1155          */
1156         if (skip_empty)
1157                 seq_putc(seq, '0');
1158
1159         seq_putc(seq, '\n');
1160 }
1161
1162 static int input_devices_seq_show(struct seq_file *seq, void *v)
1163 {
1164         struct input_dev *dev = container_of(v, struct input_dev, node);
1165         const char *path = kobject_get_path(&dev->dev.kobj, GFP_KERNEL);
1166         struct input_handle *handle;
1167
1168         seq_printf(seq, "I: Bus=%04x Vendor=%04x Product=%04x Version=%04x\n",
1169                    dev->id.bustype, dev->id.vendor, dev->id.product, dev->id.version);
1170
1171         seq_printf(seq, "N: Name=\"%s\"\n", dev->name ? dev->name : "");
1172         seq_printf(seq, "P: Phys=%s\n", dev->phys ? dev->phys : "");
1173         seq_printf(seq, "S: Sysfs=%s\n", path ? path : "");
1174         seq_printf(seq, "U: Uniq=%s\n", dev->uniq ? dev->uniq : "");
1175         seq_puts(seq, "H: Handlers=");
1176
1177         list_for_each_entry(handle, &dev->h_list, d_node)
1178                 seq_printf(seq, "%s ", handle->name);
1179         seq_putc(seq, '\n');
1180
1181         input_seq_print_bitmap(seq, "PROP", dev->propbit, INPUT_PROP_MAX);
1182
1183         input_seq_print_bitmap(seq, "EV", dev->evbit, EV_MAX);
1184         if (test_bit(EV_KEY, dev->evbit))
1185                 input_seq_print_bitmap(seq, "KEY", dev->keybit, KEY_MAX);
1186         if (test_bit(EV_REL, dev->evbit))
1187                 input_seq_print_bitmap(seq, "REL", dev->relbit, REL_MAX);
1188         if (test_bit(EV_ABS, dev->evbit))
1189                 input_seq_print_bitmap(seq, "ABS", dev->absbit, ABS_MAX);
1190         if (test_bit(EV_MSC, dev->evbit))
1191                 input_seq_print_bitmap(seq, "MSC", dev->mscbit, MSC_MAX);
1192         if (test_bit(EV_LED, dev->evbit))
1193                 input_seq_print_bitmap(seq, "LED", dev->ledbit, LED_MAX);
1194         if (test_bit(EV_SND, dev->evbit))
1195                 input_seq_print_bitmap(seq, "SND", dev->sndbit, SND_MAX);
1196         if (test_bit(EV_FF, dev->evbit))
1197                 input_seq_print_bitmap(seq, "FF", dev->ffbit, FF_MAX);
1198         if (test_bit(EV_SW, dev->evbit))
1199                 input_seq_print_bitmap(seq, "SW", dev->swbit, SW_MAX);
1200
1201         seq_putc(seq, '\n');
1202
1203         kfree(path);
1204         return 0;
1205 }
1206
1207 static const struct seq_operations input_devices_seq_ops = {
1208         .start  = input_devices_seq_start,
1209         .next   = input_devices_seq_next,
1210         .stop   = input_seq_stop,
1211         .show   = input_devices_seq_show,
1212 };
1213
1214 static int input_proc_devices_open(struct inode *inode, struct file *file)
1215 {
1216         return seq_open(file, &input_devices_seq_ops);
1217 }
1218
1219 static const struct proc_ops input_devices_proc_ops = {
1220         .proc_open      = input_proc_devices_open,
1221         .proc_poll      = input_proc_devices_poll,
1222         .proc_read      = seq_read,
1223         .proc_lseek     = seq_lseek,
1224         .proc_release   = seq_release,
1225 };
1226
1227 static void *input_handlers_seq_start(struct seq_file *seq, loff_t *pos)
1228 {
1229         union input_seq_state *state = (union input_seq_state *)&seq->private;
1230         int error;
1231
1232         /* We need to fit into seq->private pointer */
1233         BUILD_BUG_ON(sizeof(union input_seq_state) != sizeof(seq->private));
1234
1235         error = mutex_lock_interruptible(&input_mutex);
1236         if (error) {
1237                 state->mutex_acquired = false;
1238                 return ERR_PTR(error);
1239         }
1240
1241         state->mutex_acquired = true;
1242         state->pos = *pos;
1243
1244         return seq_list_start(&input_handler_list, *pos);
1245 }
1246
1247 static void *input_handlers_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1248 {
1249         union input_seq_state *state = (union input_seq_state *)&seq->private;
1250
1251         state->pos = *pos + 1;
1252         return seq_list_next(v, &input_handler_list, pos);
1253 }
1254
1255 static int input_handlers_seq_show(struct seq_file *seq, void *v)
1256 {
1257         struct input_handler *handler = container_of(v, struct input_handler, node);
1258         union input_seq_state *state = (union input_seq_state *)&seq->private;
1259
1260         seq_printf(seq, "N: Number=%u Name=%s", state->pos, handler->name);
1261         if (handler->filter)
1262                 seq_puts(seq, " (filter)");
1263         if (handler->legacy_minors)
1264                 seq_printf(seq, " Minor=%d", handler->minor);
1265         seq_putc(seq, '\n');
1266
1267         return 0;
1268 }
1269
1270 static const struct seq_operations input_handlers_seq_ops = {
1271         .start  = input_handlers_seq_start,
1272         .next   = input_handlers_seq_next,
1273         .stop   = input_seq_stop,
1274         .show   = input_handlers_seq_show,
1275 };
1276
1277 static int input_proc_handlers_open(struct inode *inode, struct file *file)
1278 {
1279         return seq_open(file, &input_handlers_seq_ops);
1280 }
1281
1282 static const struct proc_ops input_handlers_proc_ops = {
1283         .proc_open      = input_proc_handlers_open,
1284         .proc_read      = seq_read,
1285         .proc_lseek     = seq_lseek,
1286         .proc_release   = seq_release,
1287 };
1288
1289 static int __init input_proc_init(void)
1290 {
1291         struct proc_dir_entry *entry;
1292
1293         proc_bus_input_dir = proc_mkdir("bus/input", NULL);
1294         if (!proc_bus_input_dir)
1295                 return -ENOMEM;
1296
1297         entry = proc_create("devices", 0, proc_bus_input_dir,
1298                             &input_devices_proc_ops);
1299         if (!entry)
1300                 goto fail1;
1301
1302         entry = proc_create("handlers", 0, proc_bus_input_dir,
1303                             &input_handlers_proc_ops);
1304         if (!entry)
1305                 goto fail2;
1306
1307         return 0;
1308
1309  fail2: remove_proc_entry("devices", proc_bus_input_dir);
1310  fail1: remove_proc_entry("bus/input", NULL);
1311         return -ENOMEM;
1312 }
1313
1314 static void input_proc_exit(void)
1315 {
1316         remove_proc_entry("devices", proc_bus_input_dir);
1317         remove_proc_entry("handlers", proc_bus_input_dir);
1318         remove_proc_entry("bus/input", NULL);
1319 }
1320
1321 #else /* !CONFIG_PROC_FS */
1322 static inline void input_wakeup_procfs_readers(void) { }
1323 static inline int input_proc_init(void) { return 0; }
1324 static inline void input_proc_exit(void) { }
1325 #endif
1326
1327 #define INPUT_DEV_STRING_ATTR_SHOW(name)                                \
1328 static ssize_t input_dev_show_##name(struct device *dev,                \
1329                                      struct device_attribute *attr,     \
1330                                      char *buf)                         \
1331 {                                                                       \
1332         struct input_dev *input_dev = to_input_dev(dev);                \
1333                                                                         \
1334         return scnprintf(buf, PAGE_SIZE, "%s\n",                        \
1335                          input_dev->name ? input_dev->name : "");       \
1336 }                                                                       \
1337 static DEVICE_ATTR(name, S_IRUGO, input_dev_show_##name, NULL)
1338
1339 INPUT_DEV_STRING_ATTR_SHOW(name);
1340 INPUT_DEV_STRING_ATTR_SHOW(phys);
1341 INPUT_DEV_STRING_ATTR_SHOW(uniq);
1342
1343 static int input_print_modalias_bits(char *buf, int size,
1344                                      char name, unsigned long *bm,
1345                                      unsigned int min_bit, unsigned int max_bit)
1346 {
1347         int len = 0, i;
1348
1349         len += snprintf(buf, max(size, 0), "%c", name);
1350         for (i = min_bit; i < max_bit; i++)
1351                 if (bm[BIT_WORD(i)] & BIT_MASK(i))
1352                         len += snprintf(buf + len, max(size - len, 0), "%X,", i);
1353         return len;
1354 }
1355
1356 static int input_print_modalias(char *buf, int size, struct input_dev *id,
1357                                 int add_cr)
1358 {
1359         int len;
1360
1361         len = snprintf(buf, max(size, 0),
1362                        "input:b%04Xv%04Xp%04Xe%04X-",
1363                        id->id.bustype, id->id.vendor,
1364                        id->id.product, id->id.version);
1365
1366         len += input_print_modalias_bits(buf + len, size - len,
1367                                 'e', id->evbit, 0, EV_MAX);
1368         len += input_print_modalias_bits(buf + len, size - len,
1369                                 'k', id->keybit, KEY_MIN_INTERESTING, KEY_MAX);
1370         len += input_print_modalias_bits(buf + len, size - len,
1371                                 'r', id->relbit, 0, REL_MAX);
1372         len += input_print_modalias_bits(buf + len, size - len,
1373                                 'a', id->absbit, 0, ABS_MAX);
1374         len += input_print_modalias_bits(buf + len, size - len,
1375                                 'm', id->mscbit, 0, MSC_MAX);
1376         len += input_print_modalias_bits(buf + len, size - len,
1377                                 'l', id->ledbit, 0, LED_MAX);
1378         len += input_print_modalias_bits(buf + len, size - len,
1379                                 's', id->sndbit, 0, SND_MAX);
1380         len += input_print_modalias_bits(buf + len, size - len,
1381                                 'f', id->ffbit, 0, FF_MAX);
1382         len += input_print_modalias_bits(buf + len, size - len,
1383                                 'w', id->swbit, 0, SW_MAX);
1384
1385         if (add_cr)
1386                 len += snprintf(buf + len, max(size - len, 0), "\n");
1387
1388         return len;
1389 }
1390
1391 static ssize_t input_dev_show_modalias(struct device *dev,
1392                                        struct device_attribute *attr,
1393                                        char *buf)
1394 {
1395         struct input_dev *id = to_input_dev(dev);
1396         ssize_t len;
1397
1398         len = input_print_modalias(buf, PAGE_SIZE, id, 1);
1399
1400         return min_t(int, len, PAGE_SIZE);
1401 }
1402 static DEVICE_ATTR(modalias, S_IRUGO, input_dev_show_modalias, NULL);
1403
1404 static int input_print_bitmap(char *buf, int buf_size, unsigned long *bitmap,
1405                               int max, int add_cr);
1406
1407 static ssize_t input_dev_show_properties(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, input_dev->propbit,
1413                                      INPUT_PROP_MAX, true);
1414         return min_t(int, len, PAGE_SIZE);
1415 }
1416 static DEVICE_ATTR(properties, S_IRUGO, input_dev_show_properties, NULL);
1417
1418 static struct attribute *input_dev_attrs[] = {
1419         &dev_attr_name.attr,
1420         &dev_attr_phys.attr,
1421         &dev_attr_uniq.attr,
1422         &dev_attr_modalias.attr,
1423         &dev_attr_properties.attr,
1424         NULL
1425 };
1426
1427 static const struct attribute_group input_dev_attr_group = {
1428         .attrs  = input_dev_attrs,
1429 };
1430
1431 #define INPUT_DEV_ID_ATTR(name)                                         \
1432 static ssize_t input_dev_show_id_##name(struct device *dev,             \
1433                                         struct device_attribute *attr,  \
1434                                         char *buf)                      \
1435 {                                                                       \
1436         struct input_dev *input_dev = to_input_dev(dev);                \
1437         return scnprintf(buf, PAGE_SIZE, "%04x\n", input_dev->id.name); \
1438 }                                                                       \
1439 static DEVICE_ATTR(name, S_IRUGO, input_dev_show_id_##name, NULL)
1440
1441 INPUT_DEV_ID_ATTR(bustype);
1442 INPUT_DEV_ID_ATTR(vendor);
1443 INPUT_DEV_ID_ATTR(product);
1444 INPUT_DEV_ID_ATTR(version);
1445
1446 static struct attribute *input_dev_id_attrs[] = {
1447         &dev_attr_bustype.attr,
1448         &dev_attr_vendor.attr,
1449         &dev_attr_product.attr,
1450         &dev_attr_version.attr,
1451         NULL
1452 };
1453
1454 static const struct attribute_group input_dev_id_attr_group = {
1455         .name   = "id",
1456         .attrs  = input_dev_id_attrs,
1457 };
1458
1459 static int input_print_bitmap(char *buf, int buf_size, unsigned long *bitmap,
1460                               int max, int add_cr)
1461 {
1462         int i;
1463         int len = 0;
1464         bool skip_empty = true;
1465
1466         for (i = BITS_TO_LONGS(max) - 1; i >= 0; i--) {
1467                 len += input_bits_to_string(buf + len, max(buf_size - len, 0),
1468                                             bitmap[i], skip_empty);
1469                 if (len) {
1470                         skip_empty = false;
1471                         if (i > 0)
1472                                 len += snprintf(buf + len, max(buf_size - len, 0), " ");
1473                 }
1474         }
1475
1476         /*
1477          * If no output was produced print a single 0.
1478          */
1479         if (len == 0)
1480                 len = snprintf(buf, buf_size, "%d", 0);
1481
1482         if (add_cr)
1483                 len += snprintf(buf + len, max(buf_size - len, 0), "\n");
1484
1485         return len;
1486 }
1487
1488 #define INPUT_DEV_CAP_ATTR(ev, bm)                                      \
1489 static ssize_t input_dev_show_cap_##bm(struct device *dev,              \
1490                                        struct device_attribute *attr,   \
1491                                        char *buf)                       \
1492 {                                                                       \
1493         struct input_dev *input_dev = to_input_dev(dev);                \
1494         int len = input_print_bitmap(buf, PAGE_SIZE,                    \
1495                                      input_dev->bm##bit, ev##_MAX,      \
1496                                      true);                             \
1497         return min_t(int, len, PAGE_SIZE);                              \
1498 }                                                                       \
1499 static DEVICE_ATTR(bm, S_IRUGO, input_dev_show_cap_##bm, NULL)
1500
1501 INPUT_DEV_CAP_ATTR(EV, ev);
1502 INPUT_DEV_CAP_ATTR(KEY, key);
1503 INPUT_DEV_CAP_ATTR(REL, rel);
1504 INPUT_DEV_CAP_ATTR(ABS, abs);
1505 INPUT_DEV_CAP_ATTR(MSC, msc);
1506 INPUT_DEV_CAP_ATTR(LED, led);
1507 INPUT_DEV_CAP_ATTR(SND, snd);
1508 INPUT_DEV_CAP_ATTR(FF, ff);
1509 INPUT_DEV_CAP_ATTR(SW, sw);
1510
1511 static struct attribute *input_dev_caps_attrs[] = {
1512         &dev_attr_ev.attr,
1513         &dev_attr_key.attr,
1514         &dev_attr_rel.attr,
1515         &dev_attr_abs.attr,
1516         &dev_attr_msc.attr,
1517         &dev_attr_led.attr,
1518         &dev_attr_snd.attr,
1519         &dev_attr_ff.attr,
1520         &dev_attr_sw.attr,
1521         NULL
1522 };
1523
1524 static const struct attribute_group input_dev_caps_attr_group = {
1525         .name   = "capabilities",
1526         .attrs  = input_dev_caps_attrs,
1527 };
1528
1529 static const struct attribute_group *input_dev_attr_groups[] = {
1530         &input_dev_attr_group,
1531         &input_dev_id_attr_group,
1532         &input_dev_caps_attr_group,
1533         &input_poller_attribute_group,
1534         NULL
1535 };
1536
1537 static void input_dev_release(struct device *device)
1538 {
1539         struct input_dev *dev = to_input_dev(device);
1540
1541         input_ff_destroy(dev);
1542         input_mt_destroy_slots(dev);
1543         kfree(dev->poller);
1544         kfree(dev->absinfo);
1545         kfree(dev->vals);
1546         kfree(dev);
1547
1548         module_put(THIS_MODULE);
1549 }
1550
1551 /*
1552  * Input uevent interface - loading event handlers based on
1553  * device bitfields.
1554  */
1555 static int input_add_uevent_bm_var(struct kobj_uevent_env *env,
1556                                    const char *name, unsigned long *bitmap, int max)
1557 {
1558         int len;
1559
1560         if (add_uevent_var(env, "%s", name))
1561                 return -ENOMEM;
1562
1563         len = input_print_bitmap(&env->buf[env->buflen - 1],
1564                                  sizeof(env->buf) - env->buflen,
1565                                  bitmap, max, false);
1566         if (len >= (sizeof(env->buf) - env->buflen))
1567                 return -ENOMEM;
1568
1569         env->buflen += len;
1570         return 0;
1571 }
1572
1573 static int input_add_uevent_modalias_var(struct kobj_uevent_env *env,
1574                                          struct input_dev *dev)
1575 {
1576         int len;
1577
1578         if (add_uevent_var(env, "MODALIAS="))
1579                 return -ENOMEM;
1580
1581         len = input_print_modalias(&env->buf[env->buflen - 1],
1582                                    sizeof(env->buf) - env->buflen,
1583                                    dev, 0);
1584         if (len >= (sizeof(env->buf) - env->buflen))
1585                 return -ENOMEM;
1586
1587         env->buflen += len;
1588         return 0;
1589 }
1590
1591 #define INPUT_ADD_HOTPLUG_VAR(fmt, val...)                              \
1592         do {                                                            \
1593                 int err = add_uevent_var(env, fmt, val);                \
1594                 if (err)                                                \
1595                         return err;                                     \
1596         } while (0)
1597
1598 #define INPUT_ADD_HOTPLUG_BM_VAR(name, bm, max)                         \
1599         do {                                                            \
1600                 int err = input_add_uevent_bm_var(env, name, bm, max);  \
1601                 if (err)                                                \
1602                         return err;                                     \
1603         } while (0)
1604
1605 #define INPUT_ADD_HOTPLUG_MODALIAS_VAR(dev)                             \
1606         do {                                                            \
1607                 int err = input_add_uevent_modalias_var(env, dev);      \
1608                 if (err)                                                \
1609                         return err;                                     \
1610         } while (0)
1611
1612 static int input_dev_uevent(struct device *device, struct kobj_uevent_env *env)
1613 {
1614         struct input_dev *dev = to_input_dev(device);
1615
1616         INPUT_ADD_HOTPLUG_VAR("PRODUCT=%x/%x/%x/%x",
1617                                 dev->id.bustype, dev->id.vendor,
1618                                 dev->id.product, dev->id.version);
1619         if (dev->name)
1620                 INPUT_ADD_HOTPLUG_VAR("NAME=\"%s\"", dev->name);
1621         if (dev->phys)
1622                 INPUT_ADD_HOTPLUG_VAR("PHYS=\"%s\"", dev->phys);
1623         if (dev->uniq)
1624                 INPUT_ADD_HOTPLUG_VAR("UNIQ=\"%s\"", dev->uniq);
1625
1626         INPUT_ADD_HOTPLUG_BM_VAR("PROP=", dev->propbit, INPUT_PROP_MAX);
1627
1628         INPUT_ADD_HOTPLUG_BM_VAR("EV=", dev->evbit, EV_MAX);
1629         if (test_bit(EV_KEY, dev->evbit))
1630                 INPUT_ADD_HOTPLUG_BM_VAR("KEY=", dev->keybit, KEY_MAX);
1631         if (test_bit(EV_REL, dev->evbit))
1632                 INPUT_ADD_HOTPLUG_BM_VAR("REL=", dev->relbit, REL_MAX);
1633         if (test_bit(EV_ABS, dev->evbit))
1634                 INPUT_ADD_HOTPLUG_BM_VAR("ABS=", dev->absbit, ABS_MAX);
1635         if (test_bit(EV_MSC, dev->evbit))
1636                 INPUT_ADD_HOTPLUG_BM_VAR("MSC=", dev->mscbit, MSC_MAX);
1637         if (test_bit(EV_LED, dev->evbit))
1638                 INPUT_ADD_HOTPLUG_BM_VAR("LED=", dev->ledbit, LED_MAX);
1639         if (test_bit(EV_SND, dev->evbit))
1640                 INPUT_ADD_HOTPLUG_BM_VAR("SND=", dev->sndbit, SND_MAX);
1641         if (test_bit(EV_FF, dev->evbit))
1642                 INPUT_ADD_HOTPLUG_BM_VAR("FF=", dev->ffbit, FF_MAX);
1643         if (test_bit(EV_SW, dev->evbit))
1644                 INPUT_ADD_HOTPLUG_BM_VAR("SW=", dev->swbit, SW_MAX);
1645
1646         INPUT_ADD_HOTPLUG_MODALIAS_VAR(dev);
1647
1648         return 0;
1649 }
1650
1651 #define INPUT_DO_TOGGLE(dev, type, bits, on)                            \
1652         do {                                                            \
1653                 int i;                                                  \
1654                 bool active;                                            \
1655                                                                         \
1656                 if (!test_bit(EV_##type, dev->evbit))                   \
1657                         break;                                          \
1658                                                                         \
1659                 for_each_set_bit(i, dev->bits##bit, type##_CNT) {       \
1660                         active = test_bit(i, dev->bits);                \
1661                         if (!active && !on)                             \
1662                                 continue;                               \
1663                                                                         \
1664                         dev->event(dev, EV_##type, i, on ? active : 0); \
1665                 }                                                       \
1666         } while (0)
1667
1668 static void input_dev_toggle(struct input_dev *dev, bool activate)
1669 {
1670         if (!dev->event)
1671                 return;
1672
1673         INPUT_DO_TOGGLE(dev, LED, led, activate);
1674         INPUT_DO_TOGGLE(dev, SND, snd, activate);
1675
1676         if (activate && test_bit(EV_REP, dev->evbit)) {
1677                 dev->event(dev, EV_REP, REP_PERIOD, dev->rep[REP_PERIOD]);
1678                 dev->event(dev, EV_REP, REP_DELAY, dev->rep[REP_DELAY]);
1679         }
1680 }
1681
1682 /**
1683  * input_reset_device() - reset/restore the state of input device
1684  * @dev: input device whose state needs to be reset
1685  *
1686  * This function tries to reset the state of an opened input device and
1687  * bring internal state and state if the hardware in sync with each other.
1688  * We mark all keys as released, restore LED state, repeat rate, etc.
1689  */
1690 void input_reset_device(struct input_dev *dev)
1691 {
1692         unsigned long flags;
1693
1694         mutex_lock(&dev->mutex);
1695         spin_lock_irqsave(&dev->event_lock, flags);
1696
1697         input_dev_toggle(dev, true);
1698         input_dev_release_keys(dev);
1699
1700         spin_unlock_irqrestore(&dev->event_lock, flags);
1701         mutex_unlock(&dev->mutex);
1702 }
1703 EXPORT_SYMBOL(input_reset_device);
1704
1705 #ifdef CONFIG_PM_SLEEP
1706 static int input_dev_suspend(struct device *dev)
1707 {
1708         struct input_dev *input_dev = to_input_dev(dev);
1709
1710         spin_lock_irq(&input_dev->event_lock);
1711
1712         /*
1713          * Keys that are pressed now are unlikely to be
1714          * still pressed when we resume.
1715          */
1716         input_dev_release_keys(input_dev);
1717
1718         /* Turn off LEDs and sounds, if any are active. */
1719         input_dev_toggle(input_dev, false);
1720
1721         spin_unlock_irq(&input_dev->event_lock);
1722
1723         return 0;
1724 }
1725
1726 static int input_dev_resume(struct device *dev)
1727 {
1728         struct input_dev *input_dev = to_input_dev(dev);
1729
1730         spin_lock_irq(&input_dev->event_lock);
1731
1732         /* Restore state of LEDs and sounds, if any were active. */
1733         input_dev_toggle(input_dev, true);
1734
1735         spin_unlock_irq(&input_dev->event_lock);
1736
1737         return 0;
1738 }
1739
1740 static int input_dev_freeze(struct device *dev)
1741 {
1742         struct input_dev *input_dev = to_input_dev(dev);
1743
1744         spin_lock_irq(&input_dev->event_lock);
1745
1746         /*
1747          * Keys that are pressed now are unlikely to be
1748          * still pressed when we resume.
1749          */
1750         input_dev_release_keys(input_dev);
1751
1752         spin_unlock_irq(&input_dev->event_lock);
1753
1754         return 0;
1755 }
1756
1757 static int input_dev_poweroff(struct device *dev)
1758 {
1759         struct input_dev *input_dev = to_input_dev(dev);
1760
1761         spin_lock_irq(&input_dev->event_lock);
1762
1763         /* Turn off LEDs and sounds, if any are active. */
1764         input_dev_toggle(input_dev, false);
1765
1766         spin_unlock_irq(&input_dev->event_lock);
1767
1768         return 0;
1769 }
1770
1771 static const struct dev_pm_ops input_dev_pm_ops = {
1772         .suspend        = input_dev_suspend,
1773         .resume         = input_dev_resume,
1774         .freeze         = input_dev_freeze,
1775         .poweroff       = input_dev_poweroff,
1776         .restore        = input_dev_resume,
1777 };
1778 #endif /* CONFIG_PM */
1779
1780 static const struct device_type input_dev_type = {
1781         .groups         = input_dev_attr_groups,
1782         .release        = input_dev_release,
1783         .uevent         = input_dev_uevent,
1784 #ifdef CONFIG_PM_SLEEP
1785         .pm             = &input_dev_pm_ops,
1786 #endif
1787 };
1788
1789 static char *input_devnode(struct device *dev, umode_t *mode)
1790 {
1791         return kasprintf(GFP_KERNEL, "input/%s", dev_name(dev));
1792 }
1793
1794 struct class input_class = {
1795         .name           = "input",
1796         .devnode        = input_devnode,
1797 };
1798 EXPORT_SYMBOL_GPL(input_class);
1799
1800 /**
1801  * input_allocate_device - allocate memory for new input device
1802  *
1803  * Returns prepared struct input_dev or %NULL.
1804  *
1805  * NOTE: Use input_free_device() to free devices that have not been
1806  * registered; input_unregister_device() should be used for already
1807  * registered devices.
1808  */
1809 struct input_dev *input_allocate_device(void)
1810 {
1811         static atomic_t input_no = ATOMIC_INIT(-1);
1812         struct input_dev *dev;
1813
1814         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1815         if (dev) {
1816                 dev->dev.type = &input_dev_type;
1817                 dev->dev.class = &input_class;
1818                 device_initialize(&dev->dev);
1819                 mutex_init(&dev->mutex);
1820                 spin_lock_init(&dev->event_lock);
1821                 timer_setup(&dev->timer, NULL, 0);
1822                 INIT_LIST_HEAD(&dev->h_list);
1823                 INIT_LIST_HEAD(&dev->node);
1824
1825                 dev_set_name(&dev->dev, "input%lu",
1826                              (unsigned long)atomic_inc_return(&input_no));
1827
1828                 __module_get(THIS_MODULE);
1829         }
1830
1831         return dev;
1832 }
1833 EXPORT_SYMBOL(input_allocate_device);
1834
1835 struct input_devres {
1836         struct input_dev *input;
1837 };
1838
1839 static int devm_input_device_match(struct device *dev, void *res, void *data)
1840 {
1841         struct input_devres *devres = res;
1842
1843         return devres->input == data;
1844 }
1845
1846 static void devm_input_device_release(struct device *dev, void *res)
1847 {
1848         struct input_devres *devres = res;
1849         struct input_dev *input = devres->input;
1850
1851         dev_dbg(dev, "%s: dropping reference to %s\n",
1852                 __func__, dev_name(&input->dev));
1853         input_put_device(input);
1854 }
1855
1856 /**
1857  * devm_input_allocate_device - allocate managed input device
1858  * @dev: device owning the input device being created
1859  *
1860  * Returns prepared struct input_dev or %NULL.
1861  *
1862  * Managed input devices do not need to be explicitly unregistered or
1863  * freed as it will be done automatically when owner device unbinds from
1864  * its driver (or binding fails). Once managed input device is allocated,
1865  * it is ready to be set up and registered in the same fashion as regular
1866  * input device. There are no special devm_input_device_[un]register()
1867  * variants, regular ones work with both managed and unmanaged devices,
1868  * should you need them. In most cases however, managed input device need
1869  * not be explicitly unregistered or freed.
1870  *
1871  * NOTE: the owner device is set up as parent of input device and users
1872  * should not override it.
1873  */
1874 struct input_dev *devm_input_allocate_device(struct device *dev)
1875 {
1876         struct input_dev *input;
1877         struct input_devres *devres;
1878
1879         devres = devres_alloc(devm_input_device_release,
1880                               sizeof(*devres), GFP_KERNEL);
1881         if (!devres)
1882                 return NULL;
1883
1884         input = input_allocate_device();
1885         if (!input) {
1886                 devres_free(devres);
1887                 return NULL;
1888         }
1889
1890         input->dev.parent = dev;
1891         input->devres_managed = true;
1892
1893         devres->input = input;
1894         devres_add(dev, devres);
1895
1896         return input;
1897 }
1898 EXPORT_SYMBOL(devm_input_allocate_device);
1899
1900 /**
1901  * input_free_device - free memory occupied by input_dev structure
1902  * @dev: input device to free
1903  *
1904  * This function should only be used if input_register_device()
1905  * was not called yet or if it failed. Once device was registered
1906  * use input_unregister_device() and memory will be freed once last
1907  * reference to the device is dropped.
1908  *
1909  * Device should be allocated by input_allocate_device().
1910  *
1911  * NOTE: If there are references to the input device then memory
1912  * will not be freed until last reference is dropped.
1913  */
1914 void input_free_device(struct input_dev *dev)
1915 {
1916         if (dev) {
1917                 if (dev->devres_managed)
1918                         WARN_ON(devres_destroy(dev->dev.parent,
1919                                                 devm_input_device_release,
1920                                                 devm_input_device_match,
1921                                                 dev));
1922                 input_put_device(dev);
1923         }
1924 }
1925 EXPORT_SYMBOL(input_free_device);
1926
1927 /**
1928  * input_set_timestamp - set timestamp for input events
1929  * @dev: input device to set timestamp for
1930  * @timestamp: the time at which the event has occurred
1931  *   in CLOCK_MONOTONIC
1932  *
1933  * This function is intended to provide to the input system a more
1934  * accurate time of when an event actually occurred. The driver should
1935  * call this function as soon as a timestamp is acquired ensuring
1936  * clock conversions in input_set_timestamp are done correctly.
1937  *
1938  * The system entering suspend state between timestamp acquisition and
1939  * calling input_set_timestamp can result in inaccurate conversions.
1940  */
1941 void input_set_timestamp(struct input_dev *dev, ktime_t timestamp)
1942 {
1943         dev->timestamp[INPUT_CLK_MONO] = timestamp;
1944         dev->timestamp[INPUT_CLK_REAL] = ktime_mono_to_real(timestamp);
1945         dev->timestamp[INPUT_CLK_BOOT] = ktime_mono_to_any(timestamp,
1946                                                            TK_OFFS_BOOT);
1947 }
1948 EXPORT_SYMBOL(input_set_timestamp);
1949
1950 /**
1951  * input_get_timestamp - get timestamp for input events
1952  * @dev: input device to get timestamp from
1953  *
1954  * A valid timestamp is a timestamp of non-zero value.
1955  */
1956 ktime_t *input_get_timestamp(struct input_dev *dev)
1957 {
1958         const ktime_t invalid_timestamp = ktime_set(0, 0);
1959
1960         if (!ktime_compare(dev->timestamp[INPUT_CLK_MONO], invalid_timestamp))
1961                 input_set_timestamp(dev, ktime_get());
1962
1963         return dev->timestamp;
1964 }
1965 EXPORT_SYMBOL(input_get_timestamp);
1966
1967 /**
1968  * input_set_capability - mark device as capable of a certain event
1969  * @dev: device that is capable of emitting or accepting event
1970  * @type: type of the event (EV_KEY, EV_REL, etc...)
1971  * @code: event code
1972  *
1973  * In addition to setting up corresponding bit in appropriate capability
1974  * bitmap the function also adjusts dev->evbit.
1975  */
1976 void input_set_capability(struct input_dev *dev, unsigned int type, unsigned int code)
1977 {
1978         switch (type) {
1979         case EV_KEY:
1980                 __set_bit(code, dev->keybit);
1981                 break;
1982
1983         case EV_REL:
1984                 __set_bit(code, dev->relbit);
1985                 break;
1986
1987         case EV_ABS:
1988                 input_alloc_absinfo(dev);
1989                 if (!dev->absinfo)
1990                         return;
1991
1992                 __set_bit(code, dev->absbit);
1993                 break;
1994
1995         case EV_MSC:
1996                 __set_bit(code, dev->mscbit);
1997                 break;
1998
1999         case EV_SW:
2000                 __set_bit(code, dev->swbit);
2001                 break;
2002
2003         case EV_LED:
2004                 __set_bit(code, dev->ledbit);
2005                 break;
2006
2007         case EV_SND:
2008                 __set_bit(code, dev->sndbit);
2009                 break;
2010
2011         case EV_FF:
2012                 __set_bit(code, dev->ffbit);
2013                 break;
2014
2015         case EV_PWR:
2016                 /* do nothing */
2017                 break;
2018
2019         default:
2020                 pr_err("%s: unknown type %u (code %u)\n", __func__, type, code);
2021                 dump_stack();
2022                 return;
2023         }
2024
2025         __set_bit(type, dev->evbit);
2026 }
2027 EXPORT_SYMBOL(input_set_capability);
2028
2029 static unsigned int input_estimate_events_per_packet(struct input_dev *dev)
2030 {
2031         int mt_slots;
2032         int i;
2033         unsigned int events;
2034
2035         if (dev->mt) {
2036                 mt_slots = dev->mt->num_slots;
2037         } else if (test_bit(ABS_MT_TRACKING_ID, dev->absbit)) {
2038                 mt_slots = dev->absinfo[ABS_MT_TRACKING_ID].maximum -
2039                            dev->absinfo[ABS_MT_TRACKING_ID].minimum + 1,
2040                 mt_slots = clamp(mt_slots, 2, 32);
2041         } else if (test_bit(ABS_MT_POSITION_X, dev->absbit)) {
2042                 mt_slots = 2;
2043         } else {
2044                 mt_slots = 0;
2045         }
2046
2047         events = mt_slots + 1; /* count SYN_MT_REPORT and SYN_REPORT */
2048
2049         if (test_bit(EV_ABS, dev->evbit))
2050                 for_each_set_bit(i, dev->absbit, ABS_CNT)
2051                         events += input_is_mt_axis(i) ? mt_slots : 1;
2052
2053         if (test_bit(EV_REL, dev->evbit))
2054                 events += bitmap_weight(dev->relbit, REL_CNT);
2055
2056         /* Make room for KEY and MSC events */
2057         events += 7;
2058
2059         return events;
2060 }
2061
2062 #define INPUT_CLEANSE_BITMASK(dev, type, bits)                          \
2063         do {                                                            \
2064                 if (!test_bit(EV_##type, dev->evbit))                   \
2065                         memset(dev->bits##bit, 0,                       \
2066                                 sizeof(dev->bits##bit));                \
2067         } while (0)
2068
2069 static void input_cleanse_bitmasks(struct input_dev *dev)
2070 {
2071         INPUT_CLEANSE_BITMASK(dev, KEY, key);
2072         INPUT_CLEANSE_BITMASK(dev, REL, rel);
2073         INPUT_CLEANSE_BITMASK(dev, ABS, abs);
2074         INPUT_CLEANSE_BITMASK(dev, MSC, msc);
2075         INPUT_CLEANSE_BITMASK(dev, LED, led);
2076         INPUT_CLEANSE_BITMASK(dev, SND, snd);
2077         INPUT_CLEANSE_BITMASK(dev, FF, ff);
2078         INPUT_CLEANSE_BITMASK(dev, SW, sw);
2079 }
2080
2081 static void __input_unregister_device(struct input_dev *dev)
2082 {
2083         struct input_handle *handle, *next;
2084
2085         input_disconnect_device(dev);
2086
2087         mutex_lock(&input_mutex);
2088
2089         list_for_each_entry_safe(handle, next, &dev->h_list, d_node)
2090                 handle->handler->disconnect(handle);
2091         WARN_ON(!list_empty(&dev->h_list));
2092
2093         del_timer_sync(&dev->timer);
2094         list_del_init(&dev->node);
2095
2096         input_wakeup_procfs_readers();
2097
2098         mutex_unlock(&input_mutex);
2099
2100         device_del(&dev->dev);
2101 }
2102
2103 static void devm_input_device_unregister(struct device *dev, void *res)
2104 {
2105         struct input_devres *devres = res;
2106         struct input_dev *input = devres->input;
2107
2108         dev_dbg(dev, "%s: unregistering device %s\n",
2109                 __func__, dev_name(&input->dev));
2110         __input_unregister_device(input);
2111 }
2112
2113 /**
2114  * input_enable_softrepeat - enable software autorepeat
2115  * @dev: input device
2116  * @delay: repeat delay
2117  * @period: repeat period
2118  *
2119  * Enable software autorepeat on the input device.
2120  */
2121 void input_enable_softrepeat(struct input_dev *dev, int delay, int period)
2122 {
2123         dev->timer.function = input_repeat_key;
2124         dev->rep[REP_DELAY] = delay;
2125         dev->rep[REP_PERIOD] = period;
2126 }
2127 EXPORT_SYMBOL(input_enable_softrepeat);
2128
2129 /**
2130  * input_register_device - register device with input core
2131  * @dev: device to be registered
2132  *
2133  * This function registers device with input core. The device must be
2134  * allocated with input_allocate_device() and all it's capabilities
2135  * set up before registering.
2136  * If function fails the device must be freed with input_free_device().
2137  * Once device has been successfully registered it can be unregistered
2138  * with input_unregister_device(); input_free_device() should not be
2139  * called in this case.
2140  *
2141  * Note that this function is also used to register managed input devices
2142  * (ones allocated with devm_input_allocate_device()). Such managed input
2143  * devices need not be explicitly unregistered or freed, their tear down
2144  * is controlled by the devres infrastructure. It is also worth noting
2145  * that tear down of managed input devices is internally a 2-step process:
2146  * registered managed input device is first unregistered, but stays in
2147  * memory and can still handle input_event() calls (although events will
2148  * not be delivered anywhere). The freeing of managed input device will
2149  * happen later, when devres stack is unwound to the point where device
2150  * allocation was made.
2151  */
2152 int input_register_device(struct input_dev *dev)
2153 {
2154         struct input_devres *devres = NULL;
2155         struct input_handler *handler;
2156         unsigned int packet_size;
2157         const char *path;
2158         int error;
2159
2160         if (test_bit(EV_ABS, dev->evbit) && !dev->absinfo) {
2161                 dev_err(&dev->dev,
2162                         "Absolute device without dev->absinfo, refusing to register\n");
2163                 return -EINVAL;
2164         }
2165
2166         if (dev->devres_managed) {
2167                 devres = devres_alloc(devm_input_device_unregister,
2168                                       sizeof(*devres), GFP_KERNEL);
2169                 if (!devres)
2170                         return -ENOMEM;
2171
2172                 devres->input = dev;
2173         }
2174
2175         /* Every input device generates EV_SYN/SYN_REPORT events. */
2176         __set_bit(EV_SYN, dev->evbit);
2177
2178         /* KEY_RESERVED is not supposed to be transmitted to userspace. */
2179         __clear_bit(KEY_RESERVED, dev->keybit);
2180
2181         /* Make sure that bitmasks not mentioned in dev->evbit are clean. */
2182         input_cleanse_bitmasks(dev);
2183
2184         packet_size = input_estimate_events_per_packet(dev);
2185         if (dev->hint_events_per_packet < packet_size)
2186                 dev->hint_events_per_packet = packet_size;
2187
2188         dev->max_vals = dev->hint_events_per_packet + 2;
2189         dev->vals = kcalloc(dev->max_vals, sizeof(*dev->vals), GFP_KERNEL);
2190         if (!dev->vals) {
2191                 error = -ENOMEM;
2192                 goto err_devres_free;
2193         }
2194
2195         /*
2196          * If delay and period are pre-set by the driver, then autorepeating
2197          * is handled by the driver itself and we don't do it in input.c.
2198          */
2199         if (!dev->rep[REP_DELAY] && !dev->rep[REP_PERIOD])
2200                 input_enable_softrepeat(dev, 250, 33);
2201
2202         if (!dev->getkeycode)
2203                 dev->getkeycode = input_default_getkeycode;
2204
2205         if (!dev->setkeycode)
2206                 dev->setkeycode = input_default_setkeycode;
2207
2208         if (dev->poller)
2209                 input_dev_poller_finalize(dev->poller);
2210
2211         error = device_add(&dev->dev);
2212         if (error)
2213                 goto err_free_vals;
2214
2215         path = kobject_get_path(&dev->dev.kobj, GFP_KERNEL);
2216         pr_info("%s as %s\n",
2217                 dev->name ? dev->name : "Unspecified device",
2218                 path ? path : "N/A");
2219         kfree(path);
2220
2221         error = mutex_lock_interruptible(&input_mutex);
2222         if (error)
2223                 goto err_device_del;
2224
2225         list_add_tail(&dev->node, &input_dev_list);
2226
2227         list_for_each_entry(handler, &input_handler_list, node)
2228                 input_attach_handler(dev, handler);
2229
2230         input_wakeup_procfs_readers();
2231
2232         mutex_unlock(&input_mutex);
2233
2234         if (dev->devres_managed) {
2235                 dev_dbg(dev->dev.parent, "%s: registering %s with devres.\n",
2236                         __func__, dev_name(&dev->dev));
2237                 devres_add(dev->dev.parent, devres);
2238         }
2239         return 0;
2240
2241 err_device_del:
2242         device_del(&dev->dev);
2243 err_free_vals:
2244         kfree(dev->vals);
2245         dev->vals = NULL;
2246 err_devres_free:
2247         devres_free(devres);
2248         return error;
2249 }
2250 EXPORT_SYMBOL(input_register_device);
2251
2252 /**
2253  * input_unregister_device - unregister previously registered device
2254  * @dev: device to be unregistered
2255  *
2256  * This function unregisters an input device. Once device is unregistered
2257  * the caller should not try to access it as it may get freed at any moment.
2258  */
2259 void input_unregister_device(struct input_dev *dev)
2260 {
2261         if (dev->devres_managed) {
2262                 WARN_ON(devres_destroy(dev->dev.parent,
2263                                         devm_input_device_unregister,
2264                                         devm_input_device_match,
2265                                         dev));
2266                 __input_unregister_device(dev);
2267                 /*
2268                  * We do not do input_put_device() here because it will be done
2269                  * when 2nd devres fires up.
2270                  */
2271         } else {
2272                 __input_unregister_device(dev);
2273                 input_put_device(dev);
2274         }
2275 }
2276 EXPORT_SYMBOL(input_unregister_device);
2277
2278 /**
2279  * input_register_handler - register a new input handler
2280  * @handler: handler to be registered
2281  *
2282  * This function registers a new input handler (interface) for input
2283  * devices in the system and attaches it to all input devices that
2284  * are compatible with the handler.
2285  */
2286 int input_register_handler(struct input_handler *handler)
2287 {
2288         struct input_dev *dev;
2289         int error;
2290
2291         error = mutex_lock_interruptible(&input_mutex);
2292         if (error)
2293                 return error;
2294
2295         INIT_LIST_HEAD(&handler->h_list);
2296
2297         list_add_tail(&handler->node, &input_handler_list);
2298
2299         list_for_each_entry(dev, &input_dev_list, node)
2300                 input_attach_handler(dev, handler);
2301
2302         input_wakeup_procfs_readers();
2303
2304         mutex_unlock(&input_mutex);
2305         return 0;
2306 }
2307 EXPORT_SYMBOL(input_register_handler);
2308
2309 /**
2310  * input_unregister_handler - unregisters an input handler
2311  * @handler: handler to be unregistered
2312  *
2313  * This function disconnects a handler from its input devices and
2314  * removes it from lists of known handlers.
2315  */
2316 void input_unregister_handler(struct input_handler *handler)
2317 {
2318         struct input_handle *handle, *next;
2319
2320         mutex_lock(&input_mutex);
2321
2322         list_for_each_entry_safe(handle, next, &handler->h_list, h_node)
2323                 handler->disconnect(handle);
2324         WARN_ON(!list_empty(&handler->h_list));
2325
2326         list_del_init(&handler->node);
2327
2328         input_wakeup_procfs_readers();
2329
2330         mutex_unlock(&input_mutex);
2331 }
2332 EXPORT_SYMBOL(input_unregister_handler);
2333
2334 /**
2335  * input_handler_for_each_handle - handle iterator
2336  * @handler: input handler to iterate
2337  * @data: data for the callback
2338  * @fn: function to be called for each handle
2339  *
2340  * Iterate over @bus's list of devices, and call @fn for each, passing
2341  * it @data and stop when @fn returns a non-zero value. The function is
2342  * using RCU to traverse the list and therefore may be using in atomic
2343  * contexts. The @fn callback is invoked from RCU critical section and
2344  * thus must not sleep.
2345  */
2346 int input_handler_for_each_handle(struct input_handler *handler, void *data,
2347                                   int (*fn)(struct input_handle *, void *))
2348 {
2349         struct input_handle *handle;
2350         int retval = 0;
2351
2352         rcu_read_lock();
2353
2354         list_for_each_entry_rcu(handle, &handler->h_list, h_node) {
2355                 retval = fn(handle, data);
2356                 if (retval)
2357                         break;
2358         }
2359
2360         rcu_read_unlock();
2361
2362         return retval;
2363 }
2364 EXPORT_SYMBOL(input_handler_for_each_handle);
2365
2366 /**
2367  * input_register_handle - register a new input handle
2368  * @handle: handle to register
2369  *
2370  * This function puts a new input handle onto device's
2371  * and handler's lists so that events can flow through
2372  * it once it is opened using input_open_device().
2373  *
2374  * This function is supposed to be called from handler's
2375  * connect() method.
2376  */
2377 int input_register_handle(struct input_handle *handle)
2378 {
2379         struct input_handler *handler = handle->handler;
2380         struct input_dev *dev = handle->dev;
2381         int error;
2382
2383         /*
2384          * We take dev->mutex here to prevent race with
2385          * input_release_device().
2386          */
2387         error = mutex_lock_interruptible(&dev->mutex);
2388         if (error)
2389                 return error;
2390
2391         /*
2392          * Filters go to the head of the list, normal handlers
2393          * to the tail.
2394          */
2395         if (handler->filter)
2396                 list_add_rcu(&handle->d_node, &dev->h_list);
2397         else
2398                 list_add_tail_rcu(&handle->d_node, &dev->h_list);
2399
2400         mutex_unlock(&dev->mutex);
2401
2402         /*
2403          * Since we are supposed to be called from ->connect()
2404          * which is mutually exclusive with ->disconnect()
2405          * we can't be racing with input_unregister_handle()
2406          * and so separate lock is not needed here.
2407          */
2408         list_add_tail_rcu(&handle->h_node, &handler->h_list);
2409
2410         if (handler->start)
2411                 handler->start(handle);
2412
2413         return 0;
2414 }
2415 EXPORT_SYMBOL(input_register_handle);
2416
2417 /**
2418  * input_unregister_handle - unregister an input handle
2419  * @handle: handle to unregister
2420  *
2421  * This function removes input handle from device's
2422  * and handler's lists.
2423  *
2424  * This function is supposed to be called from handler's
2425  * disconnect() method.
2426  */
2427 void input_unregister_handle(struct input_handle *handle)
2428 {
2429         struct input_dev *dev = handle->dev;
2430
2431         list_del_rcu(&handle->h_node);
2432
2433         /*
2434          * Take dev->mutex to prevent race with input_release_device().
2435          */
2436         mutex_lock(&dev->mutex);
2437         list_del_rcu(&handle->d_node);
2438         mutex_unlock(&dev->mutex);
2439
2440         synchronize_rcu();
2441 }
2442 EXPORT_SYMBOL(input_unregister_handle);
2443
2444 /**
2445  * input_get_new_minor - allocates a new input minor number
2446  * @legacy_base: beginning or the legacy range to be searched
2447  * @legacy_num: size of legacy range
2448  * @allow_dynamic: whether we can also take ID from the dynamic range
2449  *
2450  * This function allocates a new device minor for from input major namespace.
2451  * Caller can request legacy minor by specifying @legacy_base and @legacy_num
2452  * parameters and whether ID can be allocated from dynamic range if there are
2453  * no free IDs in legacy range.
2454  */
2455 int input_get_new_minor(int legacy_base, unsigned int legacy_num,
2456                         bool allow_dynamic)
2457 {
2458         /*
2459          * This function should be called from input handler's ->connect()
2460          * methods, which are serialized with input_mutex, so no additional
2461          * locking is needed here.
2462          */
2463         if (legacy_base >= 0) {
2464                 int minor = ida_simple_get(&input_ida,
2465                                            legacy_base,
2466                                            legacy_base + legacy_num,
2467                                            GFP_KERNEL);
2468                 if (minor >= 0 || !allow_dynamic)
2469                         return minor;
2470         }
2471
2472         return ida_simple_get(&input_ida,
2473                               INPUT_FIRST_DYNAMIC_DEV, INPUT_MAX_CHAR_DEVICES,
2474                               GFP_KERNEL);
2475 }
2476 EXPORT_SYMBOL(input_get_new_minor);
2477
2478 /**
2479  * input_free_minor - release previously allocated minor
2480  * @minor: minor to be released
2481  *
2482  * This function releases previously allocated input minor so that it can be
2483  * reused later.
2484  */
2485 void input_free_minor(unsigned int minor)
2486 {
2487         ida_simple_remove(&input_ida, minor);
2488 }
2489 EXPORT_SYMBOL(input_free_minor);
2490
2491 static int __init input_init(void)
2492 {
2493         int err;
2494
2495         err = class_register(&input_class);
2496         if (err) {
2497                 pr_err("unable to register input_dev class\n");
2498                 return err;
2499         }
2500
2501         err = input_proc_init();
2502         if (err)
2503                 goto fail1;
2504
2505         err = register_chrdev_region(MKDEV(INPUT_MAJOR, 0),
2506                                      INPUT_MAX_CHAR_DEVICES, "input");
2507         if (err) {
2508                 pr_err("unable to register char major %d", INPUT_MAJOR);
2509                 goto fail2;
2510         }
2511
2512         return 0;
2513
2514  fail2: input_proc_exit();
2515  fail1: class_unregister(&input_class);
2516         return err;
2517 }
2518
2519 static void __exit input_exit(void)
2520 {
2521         input_proc_exit();
2522         unregister_chrdev_region(MKDEV(INPUT_MAJOR, 0),
2523                                  INPUT_MAX_CHAR_DEVICES);
2524         class_unregister(&input_class);
2525 }
2526
2527 subsys_initcall(input_init);
2528 module_exit(input_exit);