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_set_timestamp(dev, ktime_get());
 194                 input_pass_values(dev, vals, ARRAY_SIZE(vals));
 195
 196                 if (dev->rep[REP_PERIOD])
 197                         mod_timer(&dev->timer, jiffies +
 198                                         msecs_to_jiffies(dev->rep[REP_PERIOD]));
 199         }
 200
 201         spin_unlock_irqrestore(&dev->event_lock, flags);
 202 }
 203
 204 #define INPUT_IGNORE_EVENT      0
 205 #define INPUT_PASS_TO_HANDLERS  1
 206 #define INPUT_PASS_TO_DEVICE    2
 207 #define INPUT_SLOT              4
 208 #define INPUT_FLUSH             8
 209 #define INPUT_PASS_TO_ALL       (INPUT_PASS_TO_HANDLERS | INPUT_PASS_TO_DEVICE)
 210
 211 static int input_handle_abs_event(struct input_dev *dev,
 212                                   unsigned int code, int *pval)
 213 {
 214         struct input_mt *mt = dev->mt;
 215         bool is_mt_event;
 216         int *pold;
 217
 218         if (code == ABS_MT_SLOT) {
 219                 /*
 220                  * "Stage" the event; we'll flush it later, when we
 221                  * get actual touch data.
 222                  */
 223                 if (mt && *pval >= 0 && *pval < mt->num_slots)
 224                         mt->slot = *pval;
 225
 226                 return INPUT_IGNORE_EVENT;
 227         }
 228
 229         is_mt_event = input_is_mt_value(code);
 230
 231         if (!is_mt_event) {
 232                 pold = &dev->absinfo[code].value;
 233         } else if (mt) {
 234                 pold = &mt->slots[mt->slot].abs[code - ABS_MT_FIRST];
 235         } else {
 236                 /*
 237                  * Bypass filtering for multi-touch events when
 238                  * not employing slots.
 239                  */
 240                 pold = NULL;
 241         }
 242
 243         if (pold) {
 244                 *pval = input_defuzz_abs_event(*pval, *pold,
 245                                                 dev->absinfo[code].fuzz);
 246                 if (*pold == *pval)
 247                         return INPUT_IGNORE_EVENT;
 248
 249                 *pold = *pval;
 250         }
 251
 252         /* Flush pending "slot" event */
 253         if (is_mt_event && mt && mt->slot != input_abs_get_val(dev, ABS_MT_SLOT)) {
 254                 input_abs_set_val(dev, ABS_MT_SLOT, mt->slot);
 255                 return INPUT_PASS_TO_HANDLERS | INPUT_SLOT;
 256         }
 257
 258         return INPUT_PASS_TO_HANDLERS;
 259 }
 260
 261 static int input_get_disposition(struct input_dev *dev,
 262                           unsigned int type, unsigned int code, int *pval)
 263 {
 264         int disposition = INPUT_IGNORE_EVENT;
 265         int value = *pval;
 266
 267         switch (type) {
 268
 269         case EV_SYN:
 270                 switch (code) {
 271                 case SYN_CONFIG:
 272                         disposition = INPUT_PASS_TO_ALL;
 273                         break;
 274
 275                 case SYN_REPORT:
 276                         disposition = INPUT_PASS_TO_HANDLERS | INPUT_FLUSH;
 277                         break;
 278                 case SYN_MT_REPORT:
 279                         disposition = INPUT_PASS_TO_HANDLERS;
 280                         break;
 281                 }
 282                 break;
 283
 284         case EV_KEY:
 285                 if (is_event_supported(code, dev->keybit, KEY_MAX)) {
 286
 287                         /* auto-repeat bypasses state updates */
 288                         if (value == 2) {
 289                                 disposition = INPUT_PASS_TO_HANDLERS;
 290                                 break;
 291                         }
 292
 293                         if (!!test_bit(code, dev->key) != !!value) {
 294
 295                                 __change_bit(code, dev->key);
 296                                 disposition = INPUT_PASS_TO_HANDLERS;
 297                         }
 298                 }
 299                 break;
 300
 301         case EV_SW:
 302                 if (is_event_supported(code, dev->swbit, SW_MAX) &&
 303                     !!test_bit(code, dev->sw) != !!value) {
 304
 305                         __change_bit(code, dev->sw);
 306                         disposition = INPUT_PASS_TO_HANDLERS;
 307                 }
 308                 break;
 309
 310         case EV_ABS:
 311                 if (is_event_supported(code, dev->absbit, ABS_MAX))
 312                         disposition = input_handle_abs_event(dev, code, &value);
 313
 314                 break;
 315
 316         case EV_REL:
 317                 if (is_event_supported(code, dev->relbit, REL_MAX) && value)
 318                         disposition = INPUT_PASS_TO_HANDLERS;
 319
 320                 break;
 321
 322         case EV_MSC:
 323                 if (is_event_supported(code, dev->mscbit, MSC_MAX))
 324                         disposition = INPUT_PASS_TO_ALL;
 325
 326                 break;
 327
 328         case EV_LED:
 329                 if (is_event_supported(code, dev->ledbit, LED_MAX) &&
 330                     !!test_bit(code, dev->led) != !!value) {
 331
 332                         __change_bit(code, dev->led);
 333                         disposition = INPUT_PASS_TO_ALL;
 334                 }
 335                 break;
 336
 337         case EV_SND:
 338                 if (is_event_supported(code, dev->sndbit, SND_MAX)) {
 339
 340                         if (!!test_bit(code, dev->snd) != !!value)
 341                                 __change_bit(code, dev->snd);
 342                         disposition = INPUT_PASS_TO_ALL;
 343                 }
 344                 break;
 345
 346         case EV_REP:
 347                 if (code <= REP_MAX && value >= 0 && dev->rep[code] != value) {
 348                         dev->rep[code] = value;
 349                         disposition = INPUT_PASS_TO_ALL;
 350                 }
 351                 break;
 352
 353         case EV_FF:
 354                 if (value >= 0)
 355                         disposition = INPUT_PASS_TO_ALL;
 356                 break;
 357
 358         case EV_PWR:
 359                 disposition = INPUT_PASS_TO_ALL;
 360                 break;
 361         }
 362
 363         *pval = value;
 364         return disposition;
 365 }
 366
 367 static void input_handle_event(struct input_dev *dev,
 368                                unsigned int type, unsigned int code, int value)
 369 {
 370         int disposition = input_get_disposition(dev, type, code, &value);
 371
 372         if (disposition != INPUT_IGNORE_EVENT && type != EV_SYN)
 373                 add_input_randomness(type, code, value);
 374
 375         if ((disposition & INPUT_PASS_TO_DEVICE) && dev->event)
 376                 dev->event(dev, type, code, value);
 377
 378         if (!dev->vals)
 379                 return;
 380
 381         if (disposition & INPUT_PASS_TO_HANDLERS) {
 382                 struct input_value *v;
 383
 384                 if (disposition & INPUT_SLOT) {
 385                         v = &dev->vals[dev->num_vals++];
 386                         v->type = EV_ABS;
 387                         v->code = ABS_MT_SLOT;
 388                         v->value = dev->mt->slot;
 389                 }
 390
 391                 v = &dev->vals[dev->num_vals++];
 392                 v->type = type;
 393                 v->code = code;
 394                 v->value = value;
 395         }
 396
 397         if (disposition & INPUT_FLUSH) {
 398                 if (dev->num_vals >= 2)
 399                         input_pass_values(dev, dev->vals, dev->num_vals);
 400                 dev->num_vals = 0;
 401                 /*
 402                  * Reset the timestamp on flush so we won't end up
 403                  * with a stale one. Note we only need to reset the
 404                  * monolithic one as we use its presence when deciding
 405                  * whether to generate a synthetic timestamp.
 406                  */
 407                 dev->timestamp[INPUT_CLK_MONO] = ktime_set(0, 0);
 408         } else if (dev->num_vals >= dev->max_vals - 2) {
 409                 dev->vals[dev->num_vals++] = input_value_sync;
 410                 input_pass_values(dev, dev->vals, dev->num_vals);
 411                 dev->num_vals = 0;
 412         }
 413
 414 }
 415
 416 /**
 417  * input_event() - report new input event
 418  * @dev: device that generated the event
 419  * @type: type of the event
 420  * @code: event code
 421  * @value: value of the event
 422  *
 423  * This function should be used by drivers implementing various input
 424  * devices to report input events. See also input_inject_event().
 425  *
 426  * NOTE: input_event() may be safely used right after input device was
 427  * allocated with input_allocate_device(), even before it is registered
 428  * with input_register_device(), but the event will not reach any of the
 429  * input handlers. Such early invocation of input_event() may be used
 430  * to 'seed' initial state of a switch or initial position of absolute
 431  * axis, etc.
 432  */
 433 void input_event(struct input_dev *dev,
 434                  unsigned int type, unsigned int code, int value)
 435 {
 436         unsigned long flags;
 437
 438         if (is_event_supported(type, dev->evbit, EV_MAX)) {
 439
 440                 spin_lock_irqsave(&dev->event_lock, flags);
 441                 input_handle_event(dev, type, code, value);
 442                 spin_unlock_irqrestore(&dev->event_lock, flags);
 443         }
 444 }
 445 EXPORT_SYMBOL(input_event);
 446
 447 /**
 448  * input_inject_event() - send input event from input handler
 449  * @handle: input handle to send event through
 450  * @type: type of the event
 451  * @code: event code
 452  * @value: value of the event
 453  *
 454  * Similar to input_event() but will ignore event if device is
 455  * "grabbed" and handle injecting event is not the one that owns
 456  * the device.
 457  */
 458 void input_inject_event(struct input_handle *handle,
 459                         unsigned int type, unsigned int code, int value)
 460 {
 461         struct input_dev *dev = handle->dev;
 462         struct input_handle *grab;
 463         unsigned long flags;
 464
 465         if (is_event_supported(type, dev->evbit, EV_MAX)) {
 466                 spin_lock_irqsave(&dev->event_lock, flags);
 467
 468                 rcu_read_lock();
 469                 grab = rcu_dereference(dev->grab);
 470                 if (!grab || grab == handle)
 471                         input_handle_event(dev, type, code, value);
 472                 rcu_read_unlock();
 473
 474                 spin_unlock_irqrestore(&dev->event_lock, flags);
 475         }
 476 }
 477 EXPORT_SYMBOL(input_inject_event);
 478
 479 /**
 480  * input_alloc_absinfo - allocates array of input_absinfo structs
 481  * @dev: the input device emitting absolute events
 482  *
 483  * If the absinfo struct the caller asked for is already allocated, this
 484  * functions will not do anything.
 485  */
 486 void input_alloc_absinfo(struct input_dev *dev)
 487 {
 488         if (dev->absinfo)
 489                 return;
 490
 491         dev->absinfo = kcalloc(ABS_CNT, sizeof(*dev->absinfo), GFP_KERNEL);
 492         if (!dev->absinfo) {
 493                 dev_err(dev->dev.parent ?: &dev->dev,
 494                         "%s: unable to allocate memory\n", __func__);
 495                 /*
 496                  * We will handle this allocation failure in
 497                  * input_register_device() when we refuse to register input
 498                  * device with ABS bits but without absinfo.
 499                  */
 500         }
 501 }
 502 EXPORT_SYMBOL(input_alloc_absinfo);
 503
 504 void input_set_abs_params(struct input_dev *dev, unsigned int axis,
 505                           int min, int max, int fuzz, int flat)
 506 {
 507         struct input_absinfo *absinfo;
 508
 509         input_alloc_absinfo(dev);
 510         if (!dev->absinfo)
 511                 return;
 512
 513         absinfo = &dev->absinfo[axis];
 514         absinfo->minimum = min;
 515         absinfo->maximum = max;
 516         absinfo->fuzz = fuzz;
 517         absinfo->flat = flat;
 518
 519         __set_bit(EV_ABS, dev->evbit);
 520         __set_bit(axis, dev->absbit);
 521 }
 522 EXPORT_SYMBOL(input_set_abs_params);
 523
 524
 525 /**
 526  * input_grab_device - grabs device for exclusive use
 527  * @handle: input handle that wants to own the device
 528  *
 529  * When a device is grabbed by an input handle all events generated by
 530  * the device are delivered only to this handle. Also events injected
 531  * by other input handles are ignored while device is grabbed.
 532  */
 533 int input_grab_device(struct input_handle *handle)
 534 {
 535         struct input_dev *dev = handle->dev;
 536         int retval;
 537
 538         retval = mutex_lock_interruptible(&dev->mutex);
 539         if (retval)
 540                 return retval;
 541
 542         if (dev->grab) {
 543                 retval = -EBUSY;
 544                 goto out;
 545         }
 546
 547         rcu_assign_pointer(dev->grab, handle);
 548
 549  out:
 550         mutex_unlock(&dev->mutex);
 551         return retval;
 552 }
 553 EXPORT_SYMBOL(input_grab_device);
 554
 555 static void __input_release_device(struct input_handle *handle)
 556 {
 557         struct input_dev *dev = handle->dev;
 558         struct input_handle *grabber;
 559
 560         grabber = rcu_dereference_protected(dev->grab,
 561                                             lockdep_is_held(&dev->mutex));
 562         if (grabber == handle) {
 563                 rcu_assign_pointer(dev->grab, NULL);
 564                 /* Make sure input_pass_event() notices that grab is gone */
 565                 synchronize_rcu();
 566
 567                 list_for_each_entry(handle, &dev->h_list, d_node)
 568                         if (handle->open && handle->handler->start)
 569                                 handle->handler->start(handle);
 570         }
 571 }
 572
 573 /**
 574  * input_release_device - release previously grabbed device
 575  * @handle: input handle that owns the device
 576  *
 577  * Releases previously grabbed device so that other input handles can
 578  * start receiving input events. Upon release all handlers attached
 579  * to the device have their start() method called so they have a change
 580  * to synchronize device state with the rest of the system.
 581  */
 582 void input_release_device(struct input_handle *handle)
 583 {
 584         struct input_dev *dev = handle->dev;
 585
 586         mutex_lock(&dev->mutex);
 587         __input_release_device(handle);
 588         mutex_unlock(&dev->mutex);
 589 }
 590 EXPORT_SYMBOL(input_release_device);
 591
 592 /**
 593  * input_open_device - open input device
 594  * @handle: handle through which device is being accessed
 595  *
 596  * This function should be called by input handlers when they
 597  * want to start receive events from given input device.
 598  */
 599 int input_open_device(struct input_handle *handle)
 600 {
 601         struct input_dev *dev = handle->dev;
 602         int retval;
 603
 604         retval = mutex_lock_interruptible(&dev->mutex);
 605         if (retval)
 606                 return retval;
 607
 608         if (dev->going_away) {
 609                 retval = -ENODEV;
 610                 goto out;
 611         }
 612
 613         handle->open++;
 614
 615         if (dev->users++) {
 616                 /*
 617                  * Device is already opened, so we can exit immediately and
 618                  * report success.
 619                  */
 620                 goto out;
 621         }
 622
 623         if (dev->open) {
 624                 retval = dev->open(dev);
 625                 if (retval) {
 626                         dev->users--;
 627                         handle->open--;
 628                         /*
 629                          * Make sure we are not delivering any more events
 630                          * through this handle
 631                          */
 632                         synchronize_rcu();
 633                         goto out;
 634                 }
 635         }
 636
 637         if (dev->poller)
 638                 input_dev_poller_start(dev->poller);
 639
 640  out:
 641         mutex_unlock(&dev->mutex);
 642         return retval;
 643 }
 644 EXPORT_SYMBOL(input_open_device);
 645
 646 int input_flush_device(struct input_handle *handle, struct file *file)
 647 {
 648         struct input_dev *dev = handle->dev;
 649         int retval;
 650
 651         retval = mutex_lock_interruptible(&dev->mutex);
 652         if (retval)
 653                 return retval;
 654
 655         if (dev->flush)
 656                 retval = dev->flush(dev, file);
 657
 658         mutex_unlock(&dev->mutex);
 659         return retval;
 660 }
 661 EXPORT_SYMBOL(input_flush_device);
 662
 663 /**
 664  * input_close_device - close input device
 665  * @handle: handle through which device is being accessed
 666  *
 667  * This function should be called by input handlers when they
 668  * want to stop receive events from given input device.
 669  */
 670 void input_close_device(struct input_handle *handle)
 671 {
 672         struct input_dev *dev = handle->dev;
 673
 674         mutex_lock(&dev->mutex);
 675
 676         __input_release_device(handle);
 677
 678         if (!--dev->users) {
 679                 if (dev->poller)
 680                         input_dev_poller_stop(dev->poller);
 681
 682                 if (dev->close)
 683                         dev->close(dev);
 684         }
 685
 686         if (!--handle->open) {
 687                 /*
 688                  * synchronize_rcu() makes sure that input_pass_event()
 689                  * completed and that no more input events are delivered
 690                  * through this handle
 691                  */
 692                 synchronize_rcu();
 693         }
 694
 695         mutex_unlock(&dev->mutex);
 696 }
 697 EXPORT_SYMBOL(input_close_device);
 698
 699 /*
 700  * Simulate keyup events for all keys that are marked as pressed.
 701  * The function must be called with dev->event_lock held.
 702  */
 703 static void input_dev_release_keys(struct input_dev *dev)
 704 {
 705         bool need_sync = false;
 706         int code;
 707
 708         if (is_event_supported(EV_KEY, dev->evbit, EV_MAX)) {
 709                 for_each_set_bit(code, dev->key, KEY_CNT) {
 710                         input_pass_event(dev, EV_KEY, code, 0);
 711                         need_sync = true;
 712                 }
 713
 714                 if (need_sync)
 715                         input_pass_event(dev, EV_SYN, SYN_REPORT, 1);
 716
 717                 memset(dev->key, 0, sizeof(dev->key));
 718         }
 719 }
 720
 721 /*
 722  * Prepare device for unregistering
 723  */
 724 static void input_disconnect_device(struct input_dev *dev)
 725 {
 726         struct input_handle *handle;
 727
 728         /*
 729          * Mark device as going away. Note that we take dev->mutex here
 730          * not to protect access to dev->going_away but rather to ensure
 731          * that there are no threads in the middle of input_open_device()
 732          */
 733         mutex_lock(&dev->mutex);
 734         dev->going_away = true;
 735         mutex_unlock(&dev->mutex);
 736
 737         spin_lock_irq(&dev->event_lock);
 738
 739         /*
 740          * Simulate keyup events for all pressed keys so that handlers
 741          * are not left with "stuck" keys. The driver may continue
 742          * generate events even after we done here but they will not
 743          * reach any handlers.
 744          */
 745         input_dev_release_keys(dev);
 746
 747         list_for_each_entry(handle, &dev->h_list, d_node)
 748                 handle->open = 0;
 749
 750         spin_unlock_irq(&dev->event_lock);
 751 }
 752
 753 /**
 754  * input_scancode_to_scalar() - converts scancode in &struct input_keymap_entry
 755  * @ke: keymap entry containing scancode to be converted.
 756  * @scancode: pointer to the location where converted scancode should
 757  *      be stored.
 758  *
 759  * This function is used to convert scancode stored in &struct keymap_entry
 760  * into scalar form understood by legacy keymap handling methods. These
 761  * methods expect scancodes to be represented as 'unsigned int'.
 762  */
 763 int input_scancode_to_scalar(const struct input_keymap_entry *ke,
 764                              unsigned int *scancode)
 765 {
 766         switch (ke->len) {
 767         case 1:
 768                 *scancode = *((u8 *)ke->scancode);
 769                 break;
 770
 771         case 2:
 772                 *scancode = *((u16 *)ke->scancode);
 773                 break;
 774
 775         case 4:
 776                 *scancode = *((u32 *)ke->scancode);
 777                 break;
 778
 779         default:
 780                 return -EINVAL;
 781         }
 782
 783         return 0;
 784 }
 785 EXPORT_SYMBOL(input_scancode_to_scalar);
 786
 787 /*
 788  * Those routines handle the default case where no [gs]etkeycode() is
 789  * defined. In this case, an array indexed by the scancode is used.
 790  */
 791
 792 static unsigned int input_fetch_keycode(struct input_dev *dev,
 793                                         unsigned int index)
 794 {
 795         switch (dev->keycodesize) {
 796         case 1:
 797                 return ((u8 *)dev->keycode)[index];
 798
 799         case 2:
 800                 return ((u16 *)dev->keycode)[index];
 801
 802         default:
 803                 return ((u32 *)dev->keycode)[index];
 804         }
 805 }
 806
 807 static int input_default_getkeycode(struct input_dev *dev,
 808                                     struct input_keymap_entry *ke)
 809 {
 810         unsigned int index;
 811         int error;
 812
 813         if (!dev->keycodesize)
 814                 return -EINVAL;
 815
 816         if (ke->flags & INPUT_KEYMAP_BY_INDEX)
 817                 index = ke->index;
 818         else {
 819                 error = input_scancode_to_scalar(ke, &index);
 820                 if (error)
 821                         return error;
 822         }
 823
 824         if (index >= dev->keycodemax)
 825                 return -EINVAL;
 826
 827         ke->keycode = input_fetch_keycode(dev, index);
 828         ke->index = index;
 829         ke->len = sizeof(index);
 830         memcpy(ke->scancode, &index, sizeof(index));
 831
 832         return 0;
 833 }
 834
 835 static int input_default_setkeycode(struct input_dev *dev,
 836                                     const struct input_keymap_entry *ke,
 837                                     unsigned int *old_keycode)
 838 {
 839         unsigned int index;
 840         int error;
 841         int i;
 842
 843         if (!dev->keycodesize)
 844                 return -EINVAL;
 845
 846         if (ke->flags & INPUT_KEYMAP_BY_INDEX) {
 847                 index = ke->index;
 848         } else {
 849                 error = input_scancode_to_scalar(ke, &index);
 850                 if (error)
 851                         return error;
 852         }
 853
 854         if (index >= dev->keycodemax)
 855                 return -EINVAL;
 856
 857         if (dev->keycodesize < sizeof(ke->keycode) &&
 858                         (ke->keycode >> (dev->keycodesize * 8)))
 859                 return -EINVAL;
 860
 861         switch (dev->keycodesize) {
 862                 case 1: {
 863                         u8 *k = (u8 *)dev->keycode;
 864                         *old_keycode = k[index];
 865                         k[index] = ke->keycode;
 866                         break;
 867                 }
 868                 case 2: {
 869                         u16 *k = (u16 *)dev->keycode;
 870                         *old_keycode = k[index];
 871                         k[index] = ke->keycode;
 872                         break;
 873                 }
 874                 default: {
 875                         u32 *k = (u32 *)dev->keycode;
 876                         *old_keycode = k[index];
 877                         k[index] = ke->keycode;
 878                         break;
 879                 }
 880         }
 881
 882         if (*old_keycode <= KEY_MAX) {
 883                 __clear_bit(*old_keycode, dev->keybit);
 884                 for (i = 0; i < dev->keycodemax; i++) {
 885                         if (input_fetch_keycode(dev, i) == *old_keycode) {
 886                                 __set_bit(*old_keycode, dev->keybit);
 887                                 /* Setting the bit twice is useless, so break */
 888                                 break;
 889                         }
 890                 }
 891         }
 892
 893         __set_bit(ke->keycode, dev->keybit);
 894         return 0;
 895 }
 896
 897 /**
 898  * input_get_keycode - retrieve keycode currently mapped to a given scancode
 899  * @dev: input device which keymap is being queried
 900  * @ke: keymap entry
 901  *
 902  * This function should be called by anyone interested in retrieving current
 903  * keymap. Presently evdev handlers use it.
 904  */
 905 int input_get_keycode(struct input_dev *dev, struct input_keymap_entry *ke)
 906 {
 907         unsigned long flags;
 908         int retval;
 909
 910         spin_lock_irqsave(&dev->event_lock, flags);
 911         retval = dev->getkeycode(dev, ke);
 912         spin_unlock_irqrestore(&dev->event_lock, flags);
 913
 914         return retval;
 915 }
 916 EXPORT_SYMBOL(input_get_keycode);
 917
 918 /**
 919  * input_set_keycode - attribute a keycode to a given scancode
 920  * @dev: input device which keymap is being updated
 921  * @ke: new keymap entry
 922  *
 923  * This function should be called by anyone needing to update current
 924  * keymap. Presently keyboard and evdev handlers use it.
 925  */
 926 int input_set_keycode(struct input_dev *dev,
 927                       const struct input_keymap_entry *ke)
 928 {
 929         unsigned long flags;
 930         unsigned int old_keycode;
 931         int retval;
 932
 933         if (ke->keycode > KEY_MAX)
 934                 return -EINVAL;
 935
 936         spin_lock_irqsave(&dev->event_lock, flags);
 937
 938         retval = dev->setkeycode(dev, ke, &old_keycode);
 939         if (retval)
 940                 goto out;
 941
 942         /* Make sure KEY_RESERVED did not get enabled. */
 943         __clear_bit(KEY_RESERVED, dev->keybit);
 944
 945         /*
 946          * Simulate keyup event if keycode is not present
 947          * in the keymap anymore
 948          */
 949         if (old_keycode > KEY_MAX) {
 950                 dev_warn(dev->dev.parent ?: &dev->dev,
 951                          "%s: got too big old keycode %#x\n",
 952                          __func__, old_keycode);
 953         } else if (test_bit(EV_KEY, dev->evbit) &&
 954                    !is_event_supported(old_keycode, dev->keybit, KEY_MAX) &&
 955                    __test_and_clear_bit(old_keycode, dev->key)) {
 956                 struct input_value vals[] =  {
 957                         { EV_KEY, old_keycode, 0 },
 958                         input_value_sync
 959                 };
 960
 961                 input_pass_values(dev, vals, ARRAY_SIZE(vals));
 962         }
 963
 964  out:
 965         spin_unlock_irqrestore(&dev->event_lock, flags);
 966
 967         return retval;
 968 }
 969 EXPORT_SYMBOL(input_set_keycode);
 970
 971 bool input_match_device_id(const struct input_dev *dev,
 972                            const struct input_device_id *id)
 973 {
 974         if (id->flags & INPUT_DEVICE_ID_MATCH_BUS)
 975                 if (id->bustype != dev->id.bustype)
 976                         return false;
 977
 978         if (id->flags & INPUT_DEVICE_ID_MATCH_VENDOR)
 979                 if (id->vendor != dev->id.vendor)
 980                         return false;
 981
 982         if (id->flags & INPUT_DEVICE_ID_MATCH_PRODUCT)
 983                 if (id->product != dev->id.product)
 984                         return false;
 985
 986         if (id->flags & INPUT_DEVICE_ID_MATCH_VERSION)
 987                 if (id->version != dev->id.version)
 988                         return false;
 989
 990         if (!bitmap_subset(id->evbit, dev->evbit, EV_MAX) ||
 991             !bitmap_subset(id->keybit, dev->keybit, KEY_MAX) ||
 992             !bitmap_subset(id->relbit, dev->relbit, REL_MAX) ||
 993             !bitmap_subset(id->absbit, dev->absbit, ABS_MAX) ||
 994             !bitmap_subset(id->mscbit, dev->mscbit, MSC_MAX) ||
 995             !bitmap_subset(id->ledbit, dev->ledbit, LED_MAX) ||
 996             !bitmap_subset(id->sndbit, dev->sndbit, SND_MAX) ||
 997             !bitmap_subset(id->ffbit, dev->ffbit, FF_MAX) ||
 998             !bitmap_subset(id->swbit, dev->swbit, SW_MAX) ||
 999             !bitmap_subset(id->propbit, dev->propbit, INPUT_PROP_MAX)) {
1000                 return false;
1001         }
1002
1003         return true;
1004 }
1005 EXPORT_SYMBOL(input_match_device_id);
1006
1007 static const struct input_device_id *input_match_device(struct input_handler *handler,
1008                                                         struct input_dev *dev)
1009 {
1010         const struct input_device_id *id;
1011
1012         for (id = handler->id_table; id->flags || id->driver_info; id++) {
1013                 if (input_match_device_id(dev, id) &&
1014                     (!handler->match || handler->match(handler, dev))) {
1015                         return id;
1016                 }
1017         }
1018
1019         return NULL;
1020 }
1021
1022 static int input_attach_handler(struct input_dev *dev, struct input_handler *handler)
1023 {
1024         const struct input_device_id *id;
1025         int error;
1026
1027         id = input_match_device(handler, dev);
1028         if (!id)
1029                 return -ENODEV;
1030
1031         error = handler->connect(handler, dev, id);
1032         if (error && error != -ENODEV)
1033                 pr_err("failed to attach handler %s to device %s, error: %d\n",
1034                        handler->name, kobject_name(&dev->dev.kobj), error);
1035
1036         return error;
1037 }
1038
1039 #ifdef CONFIG_COMPAT
1040
1041 static int input_bits_to_string(char *buf, int buf_size,
1042                                 unsigned long bits, bool skip_empty)
1043 {
1044         int len = 0;
1045
1046         if (in_compat_syscall()) {
1047                 u32 dword = bits >> 32;
1048                 if (dword || !skip_empty)
1049                         len += snprintf(buf, buf_size, "%x ", dword);
1050
1051                 dword = bits & 0xffffffffUL;
1052                 if (dword || !skip_empty || len)
1053                         len += snprintf(buf + len, max(buf_size - len, 0),
1054                                         "%x", dword);
1055         } else {
1056                 if (bits || !skip_empty)
1057                         len += snprintf(buf, buf_size, "%lx", bits);
1058         }
1059
1060         return len;
1061 }
1062
1063 #else /* !CONFIG_COMPAT */
1064
1065 static int input_bits_to_string(char *buf, int buf_size,
1066                                 unsigned long bits, bool skip_empty)
1067 {
1068         return bits || !skip_empty ?
1069                 snprintf(buf, buf_size, "%lx", bits) : 0;
1070 }
1071
1072 #endif
1073
1074 #ifdef CONFIG_PROC_FS
1075
1076 static struct proc_dir_entry *proc_bus_input_dir;
1077 static DECLARE_WAIT_QUEUE_HEAD(input_devices_poll_wait);
1078 static int input_devices_state;
1079
1080 static inline void input_wakeup_procfs_readers(void)
1081 {
1082         input_devices_state++;
1083         wake_up(&input_devices_poll_wait);
1084 }
1085
1086 static __poll_t input_proc_devices_poll(struct file *file, poll_table *wait)
1087 {
1088         poll_wait(file, &input_devices_poll_wait, wait);
1089         if (file->f_version != input_devices_state) {
1090                 file->f_version = input_devices_state;
1091                 return EPOLLIN | EPOLLRDNORM;
1092         }
1093
1094         return 0;
1095 }
1096
1097 union input_seq_state {
1098         struct {
1099                 unsigned short pos;
1100                 bool mutex_acquired;
1101         };
1102         void *p;
1103 };
1104
1105 static void *input_devices_seq_start(struct seq_file *seq, loff_t *pos)
1106 {
1107         union input_seq_state *state = (union input_seq_state *)&seq->private;
1108         int error;
1109
1110         /* We need to fit into seq->private pointer */
1111         BUILD_BUG_ON(sizeof(union input_seq_state) != sizeof(seq->private));
1112
1113         error = mutex_lock_interruptible(&input_mutex);
1114         if (error) {
1115                 state->mutex_acquired = false;
1116                 return ERR_PTR(error);
1117         }
1118
1119         state->mutex_acquired = true;
1120
1121         return seq_list_start(&input_dev_list, *pos);
1122 }
1123
1124 static void *input_devices_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1125 {
1126         return seq_list_next(v, &input_dev_list, pos);
1127 }
1128
1129 static void input_seq_stop(struct seq_file *seq, void *v)
1130 {
1131         union input_seq_state *state = (union input_seq_state *)&seq->private;
1132
1133         if (state->mutex_acquired)
1134                 mutex_unlock(&input_mutex);
1135 }
1136
1137 static void input_seq_print_bitmap(struct seq_file *seq, const char *name,
1138                                    unsigned long *bitmap, int max)
1139 {
1140         int i;
1141         bool skip_empty = true;
1142         char buf[18];
1143
1144         seq_printf(seq, "B: %s=", name);
1145
1146         for (i = BITS_TO_LONGS(max) - 1; i >= 0; i--) {
1147                 if (input_bits_to_string(buf, sizeof(buf),
1148                                          bitmap[i], skip_empty)) {
1149                         skip_empty = false;
1150                         seq_printf(seq, "%s%s", buf, i > 0 ? " " : "");
1151                 }
1152         }
1153
1154         /*
1155          * If no output was produced print a single 0.
1156          */
1157         if (skip_empty)
1158                 seq_putc(seq, '0');
1159
1160         seq_putc(seq, '\n');
1161 }
1162
1163 static int input_devices_seq_show(struct seq_file *seq, void *v)
1164 {
1165         struct input_dev *dev = container_of(v, struct input_dev, node);
1166         const char *path = kobject_get_path(&dev->dev.kobj, GFP_KERNEL);
1167         struct input_handle *handle;
1168
1169         seq_printf(seq, "I: Bus=%04x Vendor=%04x Product=%04x Version=%04x\n",
1170                    dev->id.bustype, dev->id.vendor, dev->id.product, dev->id.version);
1171
1172         seq_printf(seq, "N: Name=\"%s\"\n", dev->name ? dev->name : "");
1173         seq_printf(seq, "P: Phys=%s\n", dev->phys ? dev->phys : "");
1174         seq_printf(seq, "S: Sysfs=%s\n", path ? path : "");
1175         seq_printf(seq, "U: Uniq=%s\n", dev->uniq ? dev->uniq : "");
1176         seq_puts(seq, "H: Handlers=");
1177
1178         list_for_each_entry(handle, &dev->h_list, d_node)
1179                 seq_printf(seq, "%s ", handle->name);
1180         seq_putc(seq, '\n');
1181
1182         input_seq_print_bitmap(seq, "PROP", dev->propbit, INPUT_PROP_MAX);
1183
1184         input_seq_print_bitmap(seq, "EV", dev->evbit, EV_MAX);
1185         if (test_bit(EV_KEY, dev->evbit))
1186                 input_seq_print_bitmap(seq, "KEY", dev->keybit, KEY_MAX);
1187         if (test_bit(EV_REL, dev->evbit))
1188                 input_seq_print_bitmap(seq, "REL", dev->relbit, REL_MAX);
1189         if (test_bit(EV_ABS, dev->evbit))
1190                 input_seq_print_bitmap(seq, "ABS", dev->absbit, ABS_MAX);
1191         if (test_bit(EV_MSC, dev->evbit))
1192                 input_seq_print_bitmap(seq, "MSC", dev->mscbit, MSC_MAX);
1193         if (test_bit(EV_LED, dev->evbit))
1194                 input_seq_print_bitmap(seq, "LED", dev->ledbit, LED_MAX);
1195         if (test_bit(EV_SND, dev->evbit))
1196                 input_seq_print_bitmap(seq, "SND", dev->sndbit, SND_MAX);
1197         if (test_bit(EV_FF, dev->evbit))
1198                 input_seq_print_bitmap(seq, "FF", dev->ffbit, FF_MAX);
1199         if (test_bit(EV_SW, dev->evbit))
1200                 input_seq_print_bitmap(seq, "SW", dev->swbit, SW_MAX);
1201
1202         seq_putc(seq, '\n');
1203
1204         kfree(path);
1205         return 0;
1206 }
1207
1208 static const struct seq_operations input_devices_seq_ops = {
1209         .start  = input_devices_seq_start,
1210         .next   = input_devices_seq_next,
1211         .stop   = input_seq_stop,
1212         .show   = input_devices_seq_show,
1213 };
1214
1215 static int input_proc_devices_open(struct inode *inode, struct file *file)
1216 {
1217         return seq_open(file, &input_devices_seq_ops);
1218 }
1219
1220 static const struct proc_ops input_devices_proc_ops = {
1221         .proc_open      = input_proc_devices_open,
1222         .proc_poll      = input_proc_devices_poll,
1223         .proc_read      = seq_read,
1224         .proc_lseek     = seq_lseek,
1225         .proc_release   = seq_release,
1226 };
1227
1228 static void *input_handlers_seq_start(struct seq_file *seq, loff_t *pos)
1229 {
1230         union input_seq_state *state = (union input_seq_state *)&seq->private;
1231         int error;
1232
1233         /* We need to fit into seq->private pointer */
1234         BUILD_BUG_ON(sizeof(union input_seq_state) != sizeof(seq->private));
1235
1236         error = mutex_lock_interruptible(&input_mutex);
1237         if (error) {
1238                 state->mutex_acquired = false;
1239                 return ERR_PTR(error);
1240         }
1241
1242         state->mutex_acquired = true;
1243         state->pos = *pos;
1244
1245         return seq_list_start(&input_handler_list, *pos);
1246 }
1247
1248 static void *input_handlers_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1249 {
1250         union input_seq_state *state = (union input_seq_state *)&seq->private;
1251
1252         state->pos = *pos + 1;
1253         return seq_list_next(v, &input_handler_list, pos);
1254 }
1255
1256 static int input_handlers_seq_show(struct seq_file *seq, void *v)
1257 {
1258         struct input_handler *handler = container_of(v, struct input_handler, node);
1259         union input_seq_state *state = (union input_seq_state *)&seq->private;
1260
1261         seq_printf(seq, "N: Number=%u Name=%s", state->pos, handler->name);
1262         if (handler->filter)
1263                 seq_puts(seq, " (filter)");
1264         if (handler->legacy_minors)
1265                 seq_printf(seq, " Minor=%d", handler->minor);
1266         seq_putc(seq, '\n');
1267
1268         return 0;
1269 }
1270
1271 static const struct seq_operations input_handlers_seq_ops = {
1272         .start  = input_handlers_seq_start,
1273         .next   = input_handlers_seq_next,
1274         .stop   = input_seq_stop,
1275         .show   = input_handlers_seq_show,
1276 };
1277
1278 static int input_proc_handlers_open(struct inode *inode, struct file *file)
1279 {
1280         return seq_open(file, &input_handlers_seq_ops);
1281 }
1282
1283 static const struct proc_ops input_handlers_proc_ops = {
1284         .proc_open      = input_proc_handlers_open,
1285         .proc_read      = seq_read,
1286         .proc_lseek     = seq_lseek,
1287         .proc_release   = seq_release,
1288 };
1289
1290 static int __init input_proc_init(void)
1291 {
1292         struct proc_dir_entry *entry;
1293
1294         proc_bus_input_dir = proc_mkdir("bus/input", NULL);
1295         if (!proc_bus_input_dir)
1296                 return -ENOMEM;
1297
1298         entry = proc_create("devices", 0, proc_bus_input_dir,
1299                             &input_devices_proc_ops);
1300         if (!entry)
1301                 goto fail1;
1302
1303         entry = proc_create("handlers", 0, proc_bus_input_dir,
1304                             &input_handlers_proc_ops);
1305         if (!entry)
1306                 goto fail2;
1307
1308         return 0;
1309
1310  fail2: remove_proc_entry("devices", proc_bus_input_dir);
1311  fail1: remove_proc_entry("bus/input", NULL);
1312         return -ENOMEM;
1313 }
1314
1315 static void input_proc_exit(void)
1316 {
1317         remove_proc_entry("devices", proc_bus_input_dir);
1318         remove_proc_entry("handlers", proc_bus_input_dir);
1319         remove_proc_entry("bus/input", NULL);
1320 }
1321
1322 #else /* !CONFIG_PROC_FS */
1323 static inline void input_wakeup_procfs_readers(void) { }
1324 static inline int input_proc_init(void) { return 0; }
1325 static inline void input_proc_exit(void) { }
1326 #endif
1327
1328 #define INPUT_DEV_STRING_ATTR_SHOW(name)                                \
1329 static ssize_t input_dev_show_##name(struct device *dev,                \
1330                                      struct device_attribute *attr,     \
1331                                      char *buf)                         \
1332 {                                                                       \
1333         struct input_dev *input_dev = to_input_dev(dev);                \
1334                                                                         \
1335         return scnprintf(buf, PAGE_SIZE, "%s\n",                        \
1336                          input_dev->name ? input_dev->name : "");       \
1337 }                                                                       \
1338 static DEVICE_ATTR(name, S_IRUGO, input_dev_show_##name, NULL)
1339
1340 INPUT_DEV_STRING_ATTR_SHOW(name);
1341 INPUT_DEV_STRING_ATTR_SHOW(phys);
1342 INPUT_DEV_STRING_ATTR_SHOW(uniq);
1343
1344 static int input_print_modalias_bits(char *buf, int size,
1345                                      char name, unsigned long *bm,
1346                                      unsigned int min_bit, unsigned int max_bit)
1347 {
1348         int len = 0, i;
1349
1350         len += snprintf(buf, max(size, 0), "%c", name);
1351         for (i = min_bit; i < max_bit; i++)
1352                 if (bm[BIT_WORD(i)] & BIT_MASK(i))
1353                         len += snprintf(buf + len, max(size - len, 0), "%X,", i);
1354         return len;
1355 }
1356
1357 static int input_print_modalias(char *buf, int size, struct input_dev *id,
1358                                 int add_cr)
1359 {
1360         int len;
1361
1362         len = snprintf(buf, max(size, 0),
1363                        "input:b%04Xv%04Xp%04Xe%04X-",
1364                        id->id.bustype, id->id.vendor,
1365                        id->id.product, id->id.version);
1366
1367         len += input_print_modalias_bits(buf + len, size - len,
1368                                 'e', id->evbit, 0, EV_MAX);
1369         len += input_print_modalias_bits(buf + len, size - len,
1370                                 'k', id->keybit, KEY_MIN_INTERESTING, KEY_MAX);
1371         len += input_print_modalias_bits(buf + len, size - len,
1372                                 'r', id->relbit, 0, REL_MAX);
1373         len += input_print_modalias_bits(buf + len, size - len,
1374                                 'a', id->absbit, 0, ABS_MAX);
1375         len += input_print_modalias_bits(buf + len, size - len,
1376                                 'm', id->mscbit, 0, MSC_MAX);
1377         len += input_print_modalias_bits(buf + len, size - len,
1378                                 'l', id->ledbit, 0, LED_MAX);
1379         len += input_print_modalias_bits(buf + len, size - len,
1380                                 's', id->sndbit, 0, SND_MAX);
1381         len += input_print_modalias_bits(buf + len, size - len,
1382                                 'f', id->ffbit, 0, FF_MAX);
1383         len += input_print_modalias_bits(buf + len, size - len,
1384                                 'w', id->swbit, 0, SW_MAX);
1385
1386         if (add_cr)
1387                 len += snprintf(buf + len, max(size - len, 0), "\n");
1388
1389         return len;
1390 }
1391
1392 static ssize_t input_dev_show_modalias(struct device *dev,
1393                                        struct device_attribute *attr,
1394                                        char *buf)
1395 {
1396         struct input_dev *id = to_input_dev(dev);
1397         ssize_t len;
1398
1399         len = input_print_modalias(buf, PAGE_SIZE, id, 1);
1400
1401         return min_t(int, len, PAGE_SIZE);
1402 }
1403 static DEVICE_ATTR(modalias, S_IRUGO, input_dev_show_modalias, NULL);
1404
1405 static int input_print_bitmap(char *buf, int buf_size, unsigned long *bitmap,
1406                               int max, int add_cr);
1407
1408 static ssize_t input_dev_show_properties(struct device *dev,
1409                                          struct device_attribute *attr,
1410                                          char *buf)
1411 {
1412         struct input_dev *input_dev = to_input_dev(dev);
1413         int len = input_print_bitmap(buf, PAGE_SIZE, input_dev->propbit,
1414                                      INPUT_PROP_MAX, true);
1415         return min_t(int, len, PAGE_SIZE);
1416 }
1417 static DEVICE_ATTR(properties, S_IRUGO, input_dev_show_properties, NULL);
1418
1419 static struct attribute *input_dev_attrs[] = {
1420         &dev_attr_name.attr,
1421         &dev_attr_phys.attr,
1422         &dev_attr_uniq.attr,
1423         &dev_attr_modalias.attr,
1424         &dev_attr_properties.attr,
1425         NULL
1426 };
1427
1428 static const struct attribute_group input_dev_attr_group = {
1429         .attrs  = input_dev_attrs,
1430 };
1431
1432 #define INPUT_DEV_ID_ATTR(name)                                         \
1433 static ssize_t input_dev_show_id_##name(struct device *dev,             \
1434                                         struct device_attribute *attr,  \
1435                                         char *buf)                      \
1436 {                                                                       \
1437         struct input_dev *input_dev = to_input_dev(dev);                \
1438         return scnprintf(buf, PAGE_SIZE, "%04x\n", input_dev->id.name); \
1439 }                                                                       \
1440 static DEVICE_ATTR(name, S_IRUGO, input_dev_show_id_##name, NULL)
1441
1442 INPUT_DEV_ID_ATTR(bustype);
1443 INPUT_DEV_ID_ATTR(vendor);
1444 INPUT_DEV_ID_ATTR(product);
1445 INPUT_DEV_ID_ATTR(version);
1446
1447 static struct attribute *input_dev_id_attrs[] = {
1448         &dev_attr_bustype.attr,
1449         &dev_attr_vendor.attr,
1450         &dev_attr_product.attr,
1451         &dev_attr_version.attr,
1452         NULL
1453 };
1454
1455 static const struct attribute_group input_dev_id_attr_group = {
1456         .name   = "id",
1457         .attrs  = input_dev_id_attrs,
1458 };
1459
1460 static int input_print_bitmap(char *buf, int buf_size, unsigned long *bitmap,
1461                               int max, int add_cr)
1462 {
1463         int i;
1464         int len = 0;
1465         bool skip_empty = true;
1466
1467         for (i = BITS_TO_LONGS(max) - 1; i >= 0; i--) {
1468                 len += input_bits_to_string(buf + len, max(buf_size - len, 0),
1469                                             bitmap[i], skip_empty);
1470                 if (len) {
1471                         skip_empty = false;
1472                         if (i > 0)
1473                                 len += snprintf(buf + len, max(buf_size - len, 0), " ");
1474                 }
1475         }
1476
1477         /*
1478          * If no output was produced print a single 0.
1479          */
1480         if (len == 0)
1481                 len = snprintf(buf, buf_size, "%d", 0);
1482
1483         if (add_cr)
1484                 len += snprintf(buf + len, max(buf_size - len, 0), "\n");
1485
1486         return len;
1487 }
1488
1489 #define INPUT_DEV_CAP_ATTR(ev, bm)                                      \
1490 static ssize_t input_dev_show_cap_##bm(struct device *dev,              \
1491                                        struct device_attribute *attr,   \
1492                                        char *buf)                       \
1493 {                                                                       \
1494         struct input_dev *input_dev = to_input_dev(dev);                \
1495         int len = input_print_bitmap(buf, PAGE_SIZE,                    \
1496                                      input_dev->bm##bit, ev##_MAX,      \
1497                                      true);                             \
1498         return min_t(int, len, PAGE_SIZE);                              \
1499 }                                                                       \
1500 static DEVICE_ATTR(bm, S_IRUGO, input_dev_show_cap_##bm, NULL)
1501
1502 INPUT_DEV_CAP_ATTR(EV, ev);
1503 INPUT_DEV_CAP_ATTR(KEY, key);
1504 INPUT_DEV_CAP_ATTR(REL, rel);
1505 INPUT_DEV_CAP_ATTR(ABS, abs);
1506 INPUT_DEV_CAP_ATTR(MSC, msc);
1507 INPUT_DEV_CAP_ATTR(LED, led);
1508 INPUT_DEV_CAP_ATTR(SND, snd);
1509 INPUT_DEV_CAP_ATTR(FF, ff);
1510 INPUT_DEV_CAP_ATTR(SW, sw);
1511
1512 static struct attribute *input_dev_caps_attrs[] = {
1513         &dev_attr_ev.attr,
1514         &dev_attr_key.attr,
1515         &dev_attr_rel.attr,
1516         &dev_attr_abs.attr,
1517         &dev_attr_msc.attr,
1518         &dev_attr_led.attr,
1519         &dev_attr_snd.attr,
1520         &dev_attr_ff.attr,
1521         &dev_attr_sw.attr,
1522         NULL
1523 };
1524
1525 static const struct attribute_group input_dev_caps_attr_group = {
1526         .name   = "capabilities",
1527         .attrs  = input_dev_caps_attrs,
1528 };
1529
1530 static const struct attribute_group *input_dev_attr_groups[] = {
1531         &input_dev_attr_group,
1532         &input_dev_id_attr_group,
1533         &input_dev_caps_attr_group,
1534         &input_poller_attribute_group,
1535         NULL
1536 };
1537
1538 static void input_dev_release(struct device *device)
1539 {
1540         struct input_dev *dev = to_input_dev(device);
1541
1542         input_ff_destroy(dev);
1543         input_mt_destroy_slots(dev);
1544         kfree(dev->poller);
1545         kfree(dev->absinfo);
1546         kfree(dev->vals);
1547         kfree(dev);
1548
1549         module_put(THIS_MODULE);
1550 }
1551
1552 /*
1553  * Input uevent interface - loading event handlers based on
1554  * device bitfields.
1555  */
1556 static int input_add_uevent_bm_var(struct kobj_uevent_env *env,
1557                                    const char *name, unsigned long *bitmap, int max)
1558 {
1559         int len;
1560
1561         if (add_uevent_var(env, "%s", name))
1562                 return -ENOMEM;
1563
1564         len = input_print_bitmap(&env->buf[env->buflen - 1],
1565                                  sizeof(env->buf) - env->buflen,
1566                                  bitmap, max, false);
1567         if (len >= (sizeof(env->buf) - env->buflen))
1568                 return -ENOMEM;
1569
1570         env->buflen += len;
1571         return 0;
1572 }
1573
1574 static int input_add_uevent_modalias_var(struct kobj_uevent_env *env,
1575                                          struct input_dev *dev)
1576 {
1577         int len;
1578
1579         if (add_uevent_var(env, "MODALIAS="))
1580                 return -ENOMEM;
1581
1582         len = input_print_modalias(&env->buf[env->buflen - 1],
1583                                    sizeof(env->buf) - env->buflen,
1584                                    dev, 0);
1585         if (len >= (sizeof(env->buf) - env->buflen))
1586                 return -ENOMEM;
1587
1588         env->buflen += len;
1589         return 0;
1590 }
1591
1592 #define INPUT_ADD_HOTPLUG_VAR(fmt, val...)                              \
1593         do {                                                            \
1594                 int err = add_uevent_var(env, fmt, val);                \
1595                 if (err)                                                \
1596                         return err;                                     \
1597         } while (0)
1598
1599 #define INPUT_ADD_HOTPLUG_BM_VAR(name, bm, max)                         \
1600         do {                                                            \
1601                 int err = input_add_uevent_bm_var(env, name, bm, max);  \
1602                 if (err)                                                \
1603                         return err;                                     \
1604         } while (0)
1605
1606 #define INPUT_ADD_HOTPLUG_MODALIAS_VAR(dev)                             \
1607         do {                                                            \
1608                 int err = input_add_uevent_modalias_var(env, dev);      \
1609                 if (err)                                                \
1610                         return err;                                     \
1611         } while (0)
1612
1613 static int input_dev_uevent(struct device *device, struct kobj_uevent_env *env)
1614 {
1615         struct input_dev *dev = to_input_dev(device);
1616
1617         INPUT_ADD_HOTPLUG_VAR("PRODUCT=%x/%x/%x/%x",
1618                                 dev->id.bustype, dev->id.vendor,
1619                                 dev->id.product, dev->id.version);
1620         if (dev->name)
1621                 INPUT_ADD_HOTPLUG_VAR("NAME=\"%s\"", dev->name);
1622         if (dev->phys)
1623                 INPUT_ADD_HOTPLUG_VAR("PHYS=\"%s\"", dev->phys);
1624         if (dev->uniq)
1625                 INPUT_ADD_HOTPLUG_VAR("UNIQ=\"%s\"", dev->uniq);
1626
1627         INPUT_ADD_HOTPLUG_BM_VAR("PROP=", dev->propbit, INPUT_PROP_MAX);
1628
1629         INPUT_ADD_HOTPLUG_BM_VAR("EV=", dev->evbit, EV_MAX);
1630         if (test_bit(EV_KEY, dev->evbit))
1631                 INPUT_ADD_HOTPLUG_BM_VAR("KEY=", dev->keybit, KEY_MAX);
1632         if (test_bit(EV_REL, dev->evbit))
1633                 INPUT_ADD_HOTPLUG_BM_VAR("REL=", dev->relbit, REL_MAX);
1634         if (test_bit(EV_ABS, dev->evbit))
1635                 INPUT_ADD_HOTPLUG_BM_VAR("ABS=", dev->absbit, ABS_MAX);
1636         if (test_bit(EV_MSC, dev->evbit))
1637                 INPUT_ADD_HOTPLUG_BM_VAR("MSC=", dev->mscbit, MSC_MAX);
1638         if (test_bit(EV_LED, dev->evbit))
1639                 INPUT_ADD_HOTPLUG_BM_VAR("LED=", dev->ledbit, LED_MAX);
1640         if (test_bit(EV_SND, dev->evbit))
1641                 INPUT_ADD_HOTPLUG_BM_VAR("SND=", dev->sndbit, SND_MAX);
1642         if (test_bit(EV_FF, dev->evbit))
1643                 INPUT_ADD_HOTPLUG_BM_VAR("FF=", dev->ffbit, FF_MAX);
1644         if (test_bit(EV_SW, dev->evbit))
1645                 INPUT_ADD_HOTPLUG_BM_VAR("SW=", dev->swbit, SW_MAX);
1646
1647         INPUT_ADD_HOTPLUG_MODALIAS_VAR(dev);
1648
1649         return 0;
1650 }
1651
1652 #define INPUT_DO_TOGGLE(dev, type, bits, on)                            \
1653         do {                                                            \
1654                 int i;                                                  \
1655                 bool active;                                            \
1656                                                                         \
1657                 if (!test_bit(EV_##type, dev->evbit))                   \
1658                         break;                                          \
1659                                                                         \
1660                 for_each_set_bit(i, dev->bits##bit, type##_CNT) {       \
1661                         active = test_bit(i, dev->bits);                \
1662                         if (!active && !on)                             \
1663                                 continue;                               \
1664                                                                         \
1665                         dev->event(dev, EV_##type, i, on ? active : 0); \
1666                 }                                                       \
1667         } while (0)
1668
1669 static void input_dev_toggle(struct input_dev *dev, bool activate)
1670 {
1671         if (!dev->event)
1672                 return;
1673
1674         INPUT_DO_TOGGLE(dev, LED, led, activate);
1675         INPUT_DO_TOGGLE(dev, SND, snd, activate);
1676
1677         if (activate && test_bit(EV_REP, dev->evbit)) {
1678                 dev->event(dev, EV_REP, REP_PERIOD, dev->rep[REP_PERIOD]);
1679                 dev->event(dev, EV_REP, REP_DELAY, dev->rep[REP_DELAY]);
1680         }
1681 }
1682
1683 /**
1684  * input_reset_device() - reset/restore the state of input device
1685  * @dev: input device whose state needs to be reset
1686  *
1687  * This function tries to reset the state of an opened input device and
1688  * bring internal state and state if the hardware in sync with each other.
1689  * We mark all keys as released, restore LED state, repeat rate, etc.
1690  */
1691 void input_reset_device(struct input_dev *dev)
1692 {
1693         unsigned long flags;
1694
1695         mutex_lock(&dev->mutex);
1696         spin_lock_irqsave(&dev->event_lock, flags);
1697
1698         input_dev_toggle(dev, true);
1699         input_dev_release_keys(dev);
1700
1701         spin_unlock_irqrestore(&dev->event_lock, flags);
1702         mutex_unlock(&dev->mutex);
1703 }
1704 EXPORT_SYMBOL(input_reset_device);
1705
1706 #ifdef CONFIG_PM_SLEEP
1707 static int input_dev_suspend(struct device *dev)
1708 {
1709         struct input_dev *input_dev = to_input_dev(dev);
1710
1711         spin_lock_irq(&input_dev->event_lock);
1712
1713         /*
1714          * Keys that are pressed now are unlikely to be
1715          * still pressed when we resume.
1716          */
1717         input_dev_release_keys(input_dev);
1718
1719         /* Turn off LEDs and sounds, if any are active. */
1720         input_dev_toggle(input_dev, false);
1721
1722         spin_unlock_irq(&input_dev->event_lock);
1723
1724         return 0;
1725 }
1726
1727 static int input_dev_resume(struct device *dev)
1728 {
1729         struct input_dev *input_dev = to_input_dev(dev);
1730
1731         spin_lock_irq(&input_dev->event_lock);
1732
1733         /* Restore state of LEDs and sounds, if any were active. */
1734         input_dev_toggle(input_dev, true);
1735
1736         spin_unlock_irq(&input_dev->event_lock);
1737
1738         return 0;
1739 }
1740
1741 static int input_dev_freeze(struct device *dev)
1742 {
1743         struct input_dev *input_dev = to_input_dev(dev);
1744
1745         spin_lock_irq(&input_dev->event_lock);
1746
1747         /*
1748          * Keys that are pressed now are unlikely to be
1749          * still pressed when we resume.
1750          */
1751         input_dev_release_keys(input_dev);
1752
1753         spin_unlock_irq(&input_dev->event_lock);
1754
1755         return 0;
1756 }
1757
1758 static int input_dev_poweroff(struct device *dev)
1759 {
1760         struct input_dev *input_dev = to_input_dev(dev);
1761
1762         spin_lock_irq(&input_dev->event_lock);
1763
1764         /* Turn off LEDs and sounds, if any are active. */
1765         input_dev_toggle(input_dev, false);
1766
1767         spin_unlock_irq(&input_dev->event_lock);
1768
1769         return 0;
1770 }
1771
1772 static const struct dev_pm_ops input_dev_pm_ops = {
1773         .suspend        = input_dev_suspend,
1774         .resume         = input_dev_resume,
1775         .freeze         = input_dev_freeze,
1776         .poweroff       = input_dev_poweroff,
1777         .restore        = input_dev_resume,
1778 };
1779 #endif /* CONFIG_PM */
1780
1781 static const struct device_type input_dev_type = {
1782         .groups         = input_dev_attr_groups,
1783         .release        = input_dev_release,
1784         .uevent         = input_dev_uevent,
1785 #ifdef CONFIG_PM_SLEEP
1786         .pm             = &input_dev_pm_ops,
1787 #endif
1788 };
1789
1790 static char *input_devnode(struct device *dev, umode_t *mode)
1791 {
1792         return kasprintf(GFP_KERNEL, "input/%s", dev_name(dev));
1793 }
1794
1795 struct class input_class = {
1796         .name           = "input",
1797         .devnode        = input_devnode,
1798 };
1799 EXPORT_SYMBOL_GPL(input_class);
1800
1801 /**
1802  * input_allocate_device - allocate memory for new input device
1803  *
1804  * Returns prepared struct input_dev or %NULL.
1805  *
1806  * NOTE: Use input_free_device() to free devices that have not been
1807  * registered; input_unregister_device() should be used for already
1808  * registered devices.
1809  */
1810 struct input_dev *input_allocate_device(void)
1811 {
1812         static atomic_t input_no = ATOMIC_INIT(-1);
1813         struct input_dev *dev;
1814
1815         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1816         if (dev) {
1817                 dev->dev.type = &input_dev_type;
1818                 dev->dev.class = &input_class;
1819                 device_initialize(&dev->dev);
1820                 mutex_init(&dev->mutex);
1821                 spin_lock_init(&dev->event_lock);
1822                 timer_setup(&dev->timer, NULL, 0);
1823                 INIT_LIST_HEAD(&dev->h_list);
1824                 INIT_LIST_HEAD(&dev->node);
1825
1826                 dev_set_name(&dev->dev, "input%lu",
1827                              (unsigned long)atomic_inc_return(&input_no));
1828
1829                 __module_get(THIS_MODULE);
1830         }
1831
1832         return dev;
1833 }
1834 EXPORT_SYMBOL(input_allocate_device);
1835
1836 struct input_devres {
1837         struct input_dev *input;
1838 };
1839
1840 static int devm_input_device_match(struct device *dev, void *res, void *data)
1841 {
1842         struct input_devres *devres = res;
1843
1844         return devres->input == data;
1845 }
1846
1847 static void devm_input_device_release(struct device *dev, void *res)
1848 {
1849         struct input_devres *devres = res;
1850         struct input_dev *input = devres->input;
1851
1852         dev_dbg(dev, "%s: dropping reference to %s\n",
1853                 __func__, dev_name(&input->dev));
1854         input_put_device(input);
1855 }
1856
1857 /**
1858  * devm_input_allocate_device - allocate managed input device
1859  * @dev: device owning the input device being created
1860  *
1861  * Returns prepared struct input_dev or %NULL.
1862  *
1863  * Managed input devices do not need to be explicitly unregistered or
1864  * freed as it will be done automatically when owner device unbinds from
1865  * its driver (or binding fails). Once managed input device is allocated,
1866  * it is ready to be set up and registered in the same fashion as regular
1867  * input device. There are no special devm_input_device_[un]register()
1868  * variants, regular ones work with both managed and unmanaged devices,
1869  * should you need them. In most cases however, managed input device need
1870  * not be explicitly unregistered or freed.
1871  *
1872  * NOTE: the owner device is set up as parent of input device and users
1873  * should not override it.
1874  */
1875 struct input_dev *devm_input_allocate_device(struct device *dev)
1876 {
1877         struct input_dev *input;
1878         struct input_devres *devres;
1879
1880         devres = devres_alloc(devm_input_device_release,
1881                               sizeof(*devres), GFP_KERNEL);
1882         if (!devres)
1883                 return NULL;
1884
1885         input = input_allocate_device();
1886         if (!input) {
1887                 devres_free(devres);
1888                 return NULL;
1889         }
1890
1891         input->dev.parent = dev;
1892         input->devres_managed = true;
1893
1894         devres->input = input;
1895         devres_add(dev, devres);
1896
1897         return input;
1898 }
1899 EXPORT_SYMBOL(devm_input_allocate_device);
1900
1901 /**
1902  * input_free_device - free memory occupied by input_dev structure
1903  * @dev: input device to free
1904  *
1905  * This function should only be used if input_register_device()
1906  * was not called yet or if it failed. Once device was registered
1907  * use input_unregister_device() and memory will be freed once last
1908  * reference to the device is dropped.
1909  *
1910  * Device should be allocated by input_allocate_device().
1911  *
1912  * NOTE: If there are references to the input device then memory
1913  * will not be freed until last reference is dropped.
1914  */
1915 void input_free_device(struct input_dev *dev)
1916 {
1917         if (dev) {
1918                 if (dev->devres_managed)
1919                         WARN_ON(devres_destroy(dev->dev.parent,
1920                                                 devm_input_device_release,
1921                                                 devm_input_device_match,
1922                                                 dev));
1923                 input_put_device(dev);
1924         }
1925 }
1926 EXPORT_SYMBOL(input_free_device);
1927
1928 /**
1929  * input_set_timestamp - set timestamp for input events
1930  * @dev: input device to set timestamp for
1931  * @timestamp: the time at which the event has occurred
1932  *   in CLOCK_MONOTONIC
1933  *
1934  * This function is intended to provide to the input system a more
1935  * accurate time of when an event actually occurred. The driver should
1936  * call this function as soon as a timestamp is acquired ensuring
1937  * clock conversions in input_set_timestamp are done correctly.
1938  *
1939  * The system entering suspend state between timestamp acquisition and
1940  * calling input_set_timestamp can result in inaccurate conversions.
1941  */
1942 void input_set_timestamp(struct input_dev *dev, ktime_t timestamp)
1943 {
1944         dev->timestamp[INPUT_CLK_MONO] = timestamp;
1945         dev->timestamp[INPUT_CLK_REAL] = ktime_mono_to_real(timestamp);
1946         dev->timestamp[INPUT_CLK_BOOT] = ktime_mono_to_any(timestamp,
1947                                                            TK_OFFS_BOOT);
1948 }
1949 EXPORT_SYMBOL(input_set_timestamp);
1950
1951 /**
1952  * input_get_timestamp - get timestamp for input events
1953  * @dev: input device to get timestamp from
1954  *
1955  * A valid timestamp is a timestamp of non-zero value.
1956  */
1957 ktime_t *input_get_timestamp(struct input_dev *dev)
1958 {
1959         const ktime_t invalid_timestamp = ktime_set(0, 0);
1960
1961         if (!ktime_compare(dev->timestamp[INPUT_CLK_MONO], invalid_timestamp))
1962                 input_set_timestamp(dev, ktime_get());
1963
1964         return dev->timestamp;
1965 }
1966 EXPORT_SYMBOL(input_get_timestamp);
1967
1968 /**
1969  * input_set_capability - mark device as capable of a certain event
1970  * @dev: device that is capable of emitting or accepting event
1971  * @type: type of the event (EV_KEY, EV_REL, etc...)
1972  * @code: event code
1973  *
1974  * In addition to setting up corresponding bit in appropriate capability
1975  * bitmap the function also adjusts dev->evbit.
1976  */
1977 void input_set_capability(struct input_dev *dev, unsigned int type, unsigned int code)
1978 {
1979         switch (type) {
1980         case EV_KEY:
1981                 __set_bit(code, dev->keybit);
1982                 break;
1983
1984         case EV_REL:
1985                 __set_bit(code, dev->relbit);
1986                 break;
1987
1988         case EV_ABS:
1989                 input_alloc_absinfo(dev);
1990                 if (!dev->absinfo)
1991                         return;
1992
1993                 __set_bit(code, dev->absbit);
1994                 break;
1995
1996         case EV_MSC:
1997                 __set_bit(code, dev->mscbit);
1998                 break;
1999
2000         case EV_SW:
2001                 __set_bit(code, dev->swbit);
2002                 break;
2003
2004         case EV_LED:
2005                 __set_bit(code, dev->ledbit);
2006                 break;
2007
2008         case EV_SND:
2009                 __set_bit(code, dev->sndbit);
2010                 break;
2011
2012         case EV_FF:
2013                 __set_bit(code, dev->ffbit);
2014                 break;
2015
2016         case EV_PWR:
2017                 /* do nothing */
2018                 break;
2019
2020         default:
2021                 pr_err("%s: unknown type %u (code %u)\n", __func__, type, code);
2022                 dump_stack();
2023                 return;
2024         }
2025
2026         __set_bit(type, dev->evbit);
2027 }
2028 EXPORT_SYMBOL(input_set_capability);
2029
2030 static unsigned int input_estimate_events_per_packet(struct input_dev *dev)
2031 {
2032         int mt_slots;
2033         int i;
2034         unsigned int events;
2035
2036         if (dev->mt) {
2037                 mt_slots = dev->mt->num_slots;
2038         } else if (test_bit(ABS_MT_TRACKING_ID, dev->absbit)) {
2039                 mt_slots = dev->absinfo[ABS_MT_TRACKING_ID].maximum -
2040                            dev->absinfo[ABS_MT_TRACKING_ID].minimum + 1,
2041                 mt_slots = clamp(mt_slots, 2, 32);
2042         } else if (test_bit(ABS_MT_POSITION_X, dev->absbit)) {
2043                 mt_slots = 2;
2044         } else {
2045                 mt_slots = 0;
2046         }
2047
2048         events = mt_slots + 1; /* count SYN_MT_REPORT and SYN_REPORT */
2049
2050         if (test_bit(EV_ABS, dev->evbit))
2051                 for_each_set_bit(i, dev->absbit, ABS_CNT)
2052                         events += input_is_mt_axis(i) ? mt_slots : 1;
2053
2054         if (test_bit(EV_REL, dev->evbit))
2055                 events += bitmap_weight(dev->relbit, REL_CNT);
2056
2057         /* Make room for KEY and MSC events */
2058         events += 7;
2059
2060         return events;
2061 }
2062
2063 #define INPUT_CLEANSE_BITMASK(dev, type, bits)                          \
2064         do {                                                            \
2065                 if (!test_bit(EV_##type, dev->evbit))                   \
2066                         memset(dev->bits##bit, 0,                       \
2067                                 sizeof(dev->bits##bit));                \
2068         } while (0)
2069
2070 static void input_cleanse_bitmasks(struct input_dev *dev)
2071 {
2072         INPUT_CLEANSE_BITMASK(dev, KEY, key);
2073         INPUT_CLEANSE_BITMASK(dev, REL, rel);
2074         INPUT_CLEANSE_BITMASK(dev, ABS, abs);
2075         INPUT_CLEANSE_BITMASK(dev, MSC, msc);
2076         INPUT_CLEANSE_BITMASK(dev, LED, led);
2077         INPUT_CLEANSE_BITMASK(dev, SND, snd);
2078         INPUT_CLEANSE_BITMASK(dev, FF, ff);
2079         INPUT_CLEANSE_BITMASK(dev, SW, sw);
2080 }
2081
2082 static void __input_unregister_device(struct input_dev *dev)
2083 {
2084         struct input_handle *handle, *next;
2085
2086         input_disconnect_device(dev);
2087
2088         mutex_lock(&input_mutex);
2089
2090         list_for_each_entry_safe(handle, next, &dev->h_list, d_node)
2091                 handle->handler->disconnect(handle);
2092         WARN_ON(!list_empty(&dev->h_list));
2093
2094         del_timer_sync(&dev->timer);
2095         list_del_init(&dev->node);
2096
2097         input_wakeup_procfs_readers();
2098
2099         mutex_unlock(&input_mutex);
2100
2101         device_del(&dev->dev);
2102 }
2103
2104 static void devm_input_device_unregister(struct device *dev, void *res)
2105 {
2106         struct input_devres *devres = res;
2107         struct input_dev *input = devres->input;
2108
2109         dev_dbg(dev, "%s: unregistering device %s\n",
2110                 __func__, dev_name(&input->dev));
2111         __input_unregister_device(input);
2112 }
2113
2114 /**
2115  * input_enable_softrepeat - enable software autorepeat
2116  * @dev: input device
2117  * @delay: repeat delay
2118  * @period: repeat period
2119  *
2120  * Enable software autorepeat on the input device.
2121  */
2122 void input_enable_softrepeat(struct input_dev *dev, int delay, int period)
2123 {
2124         dev->timer.function = input_repeat_key;
2125         dev->rep[REP_DELAY] = delay;
2126         dev->rep[REP_PERIOD] = period;
2127 }
2128 EXPORT_SYMBOL(input_enable_softrepeat);
2129
2130 /**
2131  * input_register_device - register device with input core
2132  * @dev: device to be registered
2133  *
2134  * This function registers device with input core. The device must be
2135  * allocated with input_allocate_device() and all it's capabilities
2136  * set up before registering.
2137  * If function fails the device must be freed with input_free_device().
2138  * Once device has been successfully registered it can be unregistered
2139  * with input_unregister_device(); input_free_device() should not be
2140  * called in this case.
2141  *
2142  * Note that this function is also used to register managed input devices
2143  * (ones allocated with devm_input_allocate_device()). Such managed input
2144  * devices need not be explicitly unregistered or freed, their tear down
2145  * is controlled by the devres infrastructure. It is also worth noting
2146  * that tear down of managed input devices is internally a 2-step process:
2147  * registered managed input device is first unregistered, but stays in
2148  * memory and can still handle input_event() calls (although events will
2149  * not be delivered anywhere). The freeing of managed input device will
2150  * happen later, when devres stack is unwound to the point where device
2151  * allocation was made.
2152  */
2153 int input_register_device(struct input_dev *dev)
2154 {
2155         struct input_devres *devres = NULL;
2156         struct input_handler *handler;
2157         unsigned int packet_size;
2158         const char *path;
2159         int error;
2160
2161         if (test_bit(EV_ABS, dev->evbit) && !dev->absinfo) {
2162                 dev_err(&dev->dev,
2163                         "Absolute device without dev->absinfo, refusing to register\n");
2164                 return -EINVAL;
2165         }
2166
2167         if (dev->devres_managed) {
2168                 devres = devres_alloc(devm_input_device_unregister,
2169                                       sizeof(*devres), GFP_KERNEL);
2170                 if (!devres)
2171                         return -ENOMEM;
2172
2173                 devres->input = dev;
2174         }
2175
2176         /* Every input device generates EV_SYN/SYN_REPORT events. */
2177         __set_bit(EV_SYN, dev->evbit);
2178
2179         /* KEY_RESERVED is not supposed to be transmitted to userspace. */
2180         __clear_bit(KEY_RESERVED, dev->keybit);
2181
2182         /* Make sure that bitmasks not mentioned in dev->evbit are clean. */
2183         input_cleanse_bitmasks(dev);
2184
2185         packet_size = input_estimate_events_per_packet(dev);
2186         if (dev->hint_events_per_packet < packet_size)
2187                 dev->hint_events_per_packet = packet_size;
2188
2189         dev->max_vals = dev->hint_events_per_packet + 2;
2190         dev->vals = kcalloc(dev->max_vals, sizeof(*dev->vals), GFP_KERNEL);
2191         if (!dev->vals) {
2192                 error = -ENOMEM;
2193                 goto err_devres_free;
2194         }
2195
2196         /*
2197          * If delay and period are pre-set by the driver, then autorepeating
2198          * is handled by the driver itself and we don't do it in input.c.
2199          */
2200         if (!dev->rep[REP_DELAY] && !dev->rep[REP_PERIOD])
2201                 input_enable_softrepeat(dev, 250, 33);
2202
2203         if (!dev->getkeycode)
2204                 dev->getkeycode = input_default_getkeycode;
2205
2206         if (!dev->setkeycode)
2207                 dev->setkeycode = input_default_setkeycode;
2208
2209         if (dev->poller)
2210                 input_dev_poller_finalize(dev->poller);
2211
2212         error = device_add(&dev->dev);
2213         if (error)
2214                 goto err_free_vals;
2215
2216         path = kobject_get_path(&dev->dev.kobj, GFP_KERNEL);
2217         pr_info("%s as %s\n",
2218                 dev->name ? dev->name : "Unspecified device",
2219                 path ? path : "N/A");
2220         kfree(path);
2221
2222         error = mutex_lock_interruptible(&input_mutex);
2223         if (error)
2224                 goto err_device_del;
2225
2226         list_add_tail(&dev->node, &input_dev_list);
2227
2228         list_for_each_entry(handler, &input_handler_list, node)
2229                 input_attach_handler(dev, handler);
2230
2231         input_wakeup_procfs_readers();
2232
2233         mutex_unlock(&input_mutex);
2234
2235         if (dev->devres_managed) {
2236                 dev_dbg(dev->dev.parent, "%s: registering %s with devres.\n",
2237                         __func__, dev_name(&dev->dev));
2238                 devres_add(dev->dev.parent, devres);
2239         }
2240         return 0;
2241
2242 err_device_del:
2243         device_del(&dev->dev);
2244 err_free_vals:
2245         kfree(dev->vals);
2246         dev->vals = NULL;
2247 err_devres_free:
2248         devres_free(devres);
2249         return error;
2250 }
2251 EXPORT_SYMBOL(input_register_device);
2252
2253 /**
2254  * input_unregister_device - unregister previously registered device
2255  * @dev: device to be unregistered
2256  *
2257  * This function unregisters an input device. Once device is unregistered
2258  * the caller should not try to access it as it may get freed at any moment.
2259  */
2260 void input_unregister_device(struct input_dev *dev)
2261 {
2262         if (dev->devres_managed) {
2263                 WARN_ON(devres_destroy(dev->dev.parent,
2264                                         devm_input_device_unregister,
2265                                         devm_input_device_match,
2266                                         dev));
2267                 __input_unregister_device(dev);
2268                 /*
2269                  * We do not do input_put_device() here because it will be done
2270                  * when 2nd devres fires up.
2271                  */
2272         } else {
2273                 __input_unregister_device(dev);
2274                 input_put_device(dev);
2275         }
2276 }
2277 EXPORT_SYMBOL(input_unregister_device);
2278
2279 /**
2280  * input_register_handler - register a new input handler
2281  * @handler: handler to be registered
2282  *
2283  * This function registers a new input handler (interface) for input
2284  * devices in the system and attaches it to all input devices that
2285  * are compatible with the handler.
2286  */
2287 int input_register_handler(struct input_handler *handler)
2288 {
2289         struct input_dev *dev;
2290         int error;
2291
2292         error = mutex_lock_interruptible(&input_mutex);
2293         if (error)
2294                 return error;
2295
2296         INIT_LIST_HEAD(&handler->h_list);
2297
2298         list_add_tail(&handler->node, &input_handler_list);
2299
2300         list_for_each_entry(dev, &input_dev_list, node)
2301                 input_attach_handler(dev, handler);
2302
2303         input_wakeup_procfs_readers();
2304
2305         mutex_unlock(&input_mutex);
2306         return 0;
2307 }
2308 EXPORT_SYMBOL(input_register_handler);
2309
2310 /**
2311  * input_unregister_handler - unregisters an input handler
2312  * @handler: handler to be unregistered
2313  *
2314  * This function disconnects a handler from its input devices and
2315  * removes it from lists of known handlers.
2316  */
2317 void input_unregister_handler(struct input_handler *handler)
2318 {
2319         struct input_handle *handle, *next;
2320
2321         mutex_lock(&input_mutex);
2322
2323         list_for_each_entry_safe(handle, next, &handler->h_list, h_node)
2324                 handler->disconnect(handle);
2325         WARN_ON(!list_empty(&handler->h_list));
2326
2327         list_del_init(&handler->node);
2328
2329         input_wakeup_procfs_readers();
2330
2331         mutex_unlock(&input_mutex);
2332 }
2333 EXPORT_SYMBOL(input_unregister_handler);
2334
2335 /**
2336  * input_handler_for_each_handle - handle iterator
2337  * @handler: input handler to iterate
2338  * @data: data for the callback
2339  * @fn: function to be called for each handle
2340  *
2341  * Iterate over @bus's list of devices, and call @fn for each, passing
2342  * it @data and stop when @fn returns a non-zero value. The function is
2343  * using RCU to traverse the list and therefore may be using in atomic
2344  * contexts. The @fn callback is invoked from RCU critical section and
2345  * thus must not sleep.
2346  */
2347 int input_handler_for_each_handle(struct input_handler *handler, void *data,
2348                                   int (*fn)(struct input_handle *, void *))
2349 {
2350         struct input_handle *handle;
2351         int retval = 0;
2352
2353         rcu_read_lock();
2354
2355         list_for_each_entry_rcu(handle, &handler->h_list, h_node) {
2356                 retval = fn(handle, data);
2357                 if (retval)
2358                         break;
2359         }
2360
2361         rcu_read_unlock();
2362
2363         return retval;
2364 }
2365 EXPORT_SYMBOL(input_handler_for_each_handle);
2366
2367 /**
2368  * input_register_handle - register a new input handle
2369  * @handle: handle to register
2370  *
2371  * This function puts a new input handle onto device's
2372  * and handler's lists so that events can flow through
2373  * it once it is opened using input_open_device().
2374  *
2375  * This function is supposed to be called from handler's
2376  * connect() method.
2377  */
2378 int input_register_handle(struct input_handle *handle)
2379 {
2380         struct input_handler *handler = handle->handler;
2381         struct input_dev *dev = handle->dev;
2382         int error;
2383
2384         /*
2385          * We take dev->mutex here to prevent race with
2386          * input_release_device().
2387          */
2388         error = mutex_lock_interruptible(&dev->mutex);
2389         if (error)
2390                 return error;
2391
2392         /*
2393          * Filters go to the head of the list, normal handlers
2394          * to the tail.
2395          */
2396         if (handler->filter)
2397                 list_add_rcu(&handle->d_node, &dev->h_list);
2398         else
2399                 list_add_tail_rcu(&handle->d_node, &dev->h_list);
2400
2401         mutex_unlock(&dev->mutex);
2402
2403         /*
2404          * Since we are supposed to be called from ->connect()
2405          * which is mutually exclusive with ->disconnect()
2406          * we can't be racing with input_unregister_handle()
2407          * and so separate lock is not needed here.
2408          */
2409         list_add_tail_rcu(&handle->h_node, &handler->h_list);
2410
2411         if (handler->start)
2412                 handler->start(handle);
2413
2414         return 0;
2415 }
2416 EXPORT_SYMBOL(input_register_handle);
2417
2418 /**
2419  * input_unregister_handle - unregister an input handle
2420  * @handle: handle to unregister
2421  *
2422  * This function removes input handle from device's
2423  * and handler's lists.
2424  *
2425  * This function is supposed to be called from handler's
2426  * disconnect() method.
2427  */
2428 void input_unregister_handle(struct input_handle *handle)
2429 {
2430         struct input_dev *dev = handle->dev;
2431
2432         list_del_rcu(&handle->h_node);
2433
2434         /*
2435          * Take dev->mutex to prevent race with input_release_device().
2436          */
2437         mutex_lock(&dev->mutex);
2438         list_del_rcu(&handle->d_node);
2439         mutex_unlock(&dev->mutex);
2440
2441         synchronize_rcu();
2442 }
2443 EXPORT_SYMBOL(input_unregister_handle);
2444
2445 /**
2446  * input_get_new_minor - allocates a new input minor number
2447  * @legacy_base: beginning or the legacy range to be searched
2448  * @legacy_num: size of legacy range
2449  * @allow_dynamic: whether we can also take ID from the dynamic range
2450  *
2451  * This function allocates a new device minor for from input major namespace.
2452  * Caller can request legacy minor by specifying @legacy_base and @legacy_num
2453  * parameters and whether ID can be allocated from dynamic range if there are
2454  * no free IDs in legacy range.
2455  */
2456 int input_get_new_minor(int legacy_base, unsigned int legacy_num,
2457                         bool allow_dynamic)
2458 {
2459         /*
2460          * This function should be called from input handler's ->connect()
2461          * methods, which are serialized with input_mutex, so no additional
2462          * locking is needed here.
2463          */
2464         if (legacy_base >= 0) {
2465                 int minor = ida_simple_get(&input_ida,
2466                                            legacy_base,
2467                                            legacy_base + legacy_num,
2468                                            GFP_KERNEL);
2469                 if (minor >= 0 || !allow_dynamic)
2470                         return minor;
2471         }
2472
2473         return ida_simple_get(&input_ida,
2474                               INPUT_FIRST_DYNAMIC_DEV, INPUT_MAX_CHAR_DEVICES,
2475                               GFP_KERNEL);
2476 }
2477 EXPORT_SYMBOL(input_get_new_minor);
2478
2479 /**
2480  * input_free_minor - release previously allocated minor
2481  * @minor: minor to be released
2482  *
2483  * This function releases previously allocated input minor so that it can be
2484  * reused later.
2485  */
2486 void input_free_minor(unsigned int minor)
2487 {
2488         ida_simple_remove(&input_ida, minor);
2489 }
2490 EXPORT_SYMBOL(input_free_minor);
2491
2492 static int __init input_init(void)
2493 {
2494         int err;
2495
2496         err = class_register(&input_class);
2497         if (err) {
2498                 pr_err("unable to register input_dev class\n");
2499                 return err;
2500         }
2501
2502         err = input_proc_init();
2503         if (err)
2504                 goto fail1;
2505
2506         err = register_chrdev_region(MKDEV(INPUT_MAJOR, 0),
2507                                      INPUT_MAX_CHAR_DEVICES, "input");
2508         if (err) {
2509                 pr_err("unable to register char major %d", INPUT_MAJOR);
2510                 goto fail2;
2511         }
2512
2513         return 0;
2514
2515  fail2: input_proc_exit();
2516  fail1: class_unregister(&input_class);
2517         return err;
2518 }
2519
2520 static void __exit input_exit(void)
2521 {
2522         input_proc_exit();
2523         unregister_chrdev_region(MKDEV(INPUT_MAJOR, 0),
2524                                  INPUT_MAX_CHAR_DEVICES);
2525         class_unregister(&input_class);
2526 }
2527
2528 subsys_initcall(input_init);
2529 module_exit(input_exit);