drivers/input/input.c

   1 /*
   2  * The input core
   3  *
   4  * Copyright (c) 1999-2002 Vojtech Pavlik
   5  */
   6
   7 /*
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU General Public License version 2 as published by
  10  * the Free Software Foundation.
  11  */
  12
  13 #define pr_fmt(fmt) KBUILD_BASENAME ": " fmt
  14
  15 #include <linux/init.h>
  16 #include <linux/types.h>
  17 #include <linux/idr.h>
  18 #include <linux/input/mt.h>
  19 #include <linux/module.h>
  20 #include <linux/slab.h>
  21 #include <linux/random.h>
  22 #include <linux/major.h>
  23 #include <linux/proc_fs.h>
  24 #include <linux/sched.h>
  25 #include <linux/seq_file.h>
  26 #include <linux/poll.h>
  27 #include <linux/device.h>
  28 #include <linux/mutex.h>
  29 #include <linux/rcupdate.h>
  30 #include "input-compat.h"
  31
  32 MODULE_AUTHOR("Vojtech Pavlik <vojtech@suse.cz>");
  33 MODULE_DESCRIPTION("Input core");
  34 MODULE_LICENSE("GPL");
  35
  36 #define INPUT_MAX_CHAR_DEVICES          1024
  37 #define INPUT_FIRST_DYNAMIC_DEV         256
  38 static DEFINE_IDA(input_ida);
  39
  40 static LIST_HEAD(input_dev_list);
  41 static LIST_HEAD(input_handler_list);
  42
  43 /*
  44  * input_mutex protects access to both input_dev_list and input_handler_list.
  45  * This also causes input_[un]register_device and input_[un]register_handler
  46  * be mutually exclusive which simplifies locking in drivers implementing
  47  * input handlers.
  48  */
  49 static DEFINE_MUTEX(input_mutex);
  50
  51 static const struct input_value input_value_sync = { EV_SYN, SYN_REPORT, 1 };
  52
  53 static inline int is_event_supported(unsigned int code,
  54                                      unsigned long *bm, unsigned int max)
  55 {
  56         return code <= max && test_bit(code, bm);
  57 }
  58
  59 static int input_defuzz_abs_event(int value, int old_val, int fuzz)
  60 {
  61         if (fuzz) {
  62                 if (value > old_val - fuzz / 2 && value < old_val + fuzz / 2)
  63                         return old_val;
  64
  65                 if (value > old_val - fuzz && value < old_val + fuzz)
  66                         return (old_val * 3 + value) / 4;
  67
  68                 if (value > old_val - fuzz * 2 && value < old_val + fuzz * 2)
  69                         return (old_val + value) / 2;
  70         }
  71
  72         return value;
  73 }
  74
  75 static void input_start_autorepeat(struct input_dev *dev, int code)
  76 {
  77         if (test_bit(EV_REP, dev->evbit) &&
  78             dev->rep[REP_PERIOD] && dev->rep[REP_DELAY] &&
  79             dev->timer.data) {
  80                 dev->repeat_key = code;
  81                 mod_timer(&dev->timer,
  82                           jiffies + msecs_to_jiffies(dev->rep[REP_DELAY]));
  83         }
  84 }
  85
  86 static void input_stop_autorepeat(struct input_dev *dev)
  87 {
  88         del_timer(&dev->timer);
  89 }
  90
  91 /*
  92  * Pass event first through all filters and then, if event has not been
  93  * filtered out, through all open handles. This function is called with
  94  * dev->event_lock held and interrupts disabled.
  95  */
  96 static unsigned int input_to_handler(struct input_handle *handle,
  97                         struct input_value *vals, unsigned int count)
  98 {
  99         struct input_handler *handler = handle->handler;
 100         struct input_value *end = vals;
 101         struct input_value *v;
 102
 103         for (v = vals; v != vals + count; v++) {
 104                 if (handler->filter &&
 105                     handler->filter(handle, v->type, v->code, v->value))
 106                         continue;
 107                 if (end != v)
 108                         *end = *v;
 109                 end++;
 110         }
 111
 112         count = end - vals;
 113         if (!count)
 114                 return 0;
 115
 116         if (handler->events)
 117                 handler->events(handle, vals, count);
 118         else if (handler->event)
 119                 for (v = vals; v != end; v++)
 120                         handler->event(handle, v->type, v->code, v->value);
 121
 122         return count;
 123 }
 124
 125 /*
 126  * Pass values first through all filters and then, if event has not been
 127  * filtered out, through all open handles. This function is called with
 128  * dev->event_lock held and interrupts disabled.
 129  */
 130 static void input_pass_values(struct input_dev *dev,
 131                               struct input_value *vals, unsigned int count)
 132 {
 133         struct input_handle *handle;
 134         struct input_value *v;
 135
 136         if (!count)
 137                 return;
 138
 139         rcu_read_lock();
 140
 141         handle = rcu_dereference(dev->grab);
 142         if (handle) {
 143                 count = input_to_handler(handle, vals, count);
 144         } else {
 145                 list_for_each_entry_rcu(handle, &dev->h_list, d_node)
 146                         if (handle->open)
 147                                 count = input_to_handler(handle, vals, count);
 148         }
 149
 150         rcu_read_unlock();
 151
 152         add_input_randomness(vals->type, vals->code, vals->value);
 153
 154         /* trigger auto repeat for key events */
 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 static void input_pass_event(struct input_dev *dev,
 166                              unsigned int type, unsigned int code, int value)
 167 {
 168         struct input_value vals[] = { { type, code, value } };
 169
 170         input_pass_values(dev, vals, ARRAY_SIZE(vals));
 171 }
 172
 173 /*
 174  * Generate software autorepeat event. Note that we take
 175  * dev->event_lock here to avoid racing with input_event
 176  * which may cause keys get "stuck".
 177  */
 178 static void input_repeat_key(unsigned long data)
 179 {
 180         struct input_dev *dev = (void *) data;
 181         unsigned long flags;
 182
 183         spin_lock_irqsave(&dev->event_lock, flags);
 184
 185         if (test_bit(dev->repeat_key, dev->key) &&
 186             is_event_supported(dev->repeat_key, dev->keybit, KEY_MAX)) {
 187                 struct input_value vals[] =  {
 188                         { EV_KEY, dev->repeat_key, 2 },
 189                         input_value_sync
 190                 };
 191
 192                 input_pass_values(dev, vals, ARRAY_SIZE(vals));
 193
 194                 if (dev->rep[REP_PERIOD])
 195                         mod_timer(&dev->timer, jiffies +
 196                                         msecs_to_jiffies(dev->rep[REP_PERIOD]));
 197         }
 198
 199         spin_unlock_irqrestore(&dev->event_lock, flags);
 200 }
 201
 202 #define INPUT_IGNORE_EVENT      0
 203 #define INPUT_PASS_TO_HANDLERS  1
 204 #define INPUT_PASS_TO_DEVICE    2
 205 #define INPUT_SLOT              4
 206 #define INPUT_FLUSH             8
 207 #define INPUT_PASS_TO_ALL       (INPUT_PASS_TO_HANDLERS | INPUT_PASS_TO_DEVICE)
 208
 209 static int input_handle_abs_event(struct input_dev *dev,
 210                                   unsigned int code, int *pval)
 211 {
 212         struct input_mt *mt = dev->mt;
 213         bool is_mt_event;
 214         int *pold;
 215
 216         if (code == ABS_MT_SLOT) {
 217                 /*
 218                  * "Stage" the event; we'll flush it later, when we
 219                  * get actual touch data.
 220                  */
 221                 if (mt && *pval >= 0 && *pval < mt->num_slots)
 222                         mt->slot = *pval;
 223
 224                 return INPUT_IGNORE_EVENT;
 225         }
 226
 227         is_mt_event = input_is_mt_value(code);
 228
 229         if (!is_mt_event) {
 230                 pold = &dev->absinfo[code].value;
 231         } else if (mt) {
 232                 pold = &mt->slots[mt->slot].abs[code - ABS_MT_FIRST];
 233         } else {
 234                 /*
 235                  * Bypass filtering for multi-touch events when
 236                  * not employing slots.
 237                  */
 238                 pold = NULL;
 239         }
 240
 241         if (pold) {
 242                 *pval = input_defuzz_abs_event(*pval, *pold,
 243                                                 dev->absinfo[code].fuzz);
 244                 if (*pold == *pval)
 245                         return INPUT_IGNORE_EVENT;
 246
 247                 *pold = *pval;
 248         }
 249
 250         /* Flush pending "slot" event */
 251         if (is_mt_event && mt && mt->slot != input_abs_get_val(dev, ABS_MT_SLOT)) {
 252                 input_abs_set_val(dev, ABS_MT_SLOT, mt->slot);
 253                 return INPUT_PASS_TO_HANDLERS | INPUT_SLOT;
 254         }
 255
 256         return INPUT_PASS_TO_HANDLERS;
 257 }
 258
 259 static int input_get_disposition(struct input_dev *dev,
 260                           unsigned int type, unsigned int code, int value)
 261 {
 262         int disposition = INPUT_IGNORE_EVENT;
 263
 264         switch (type) {
 265
 266         case EV_SYN:
 267                 switch (code) {
 268                 case SYN_CONFIG:
 269                         disposition = INPUT_PASS_TO_ALL;
 270                         break;
 271
 272                 case SYN_REPORT:
 273                         disposition = INPUT_PASS_TO_HANDLERS | INPUT_FLUSH;
 274                         break;
 275                 case SYN_MT_REPORT:
 276                         disposition = INPUT_PASS_TO_HANDLERS;
 277                         break;
 278                 }
 279                 break;
 280
 281         case EV_KEY:
 282                 if (is_event_supported(code, dev->keybit, KEY_MAX)) {
 283
 284                         /* auto-repeat bypasses state updates */
 285                         if (value == 2) {
 286                                 disposition = INPUT_PASS_TO_HANDLERS;
 287                                 break;
 288                         }
 289
 290                         if (!!test_bit(code, dev->key) != !!value) {
 291
 292                                 __change_bit(code, dev->key);
 293                                 disposition = INPUT_PASS_TO_HANDLERS;
 294                         }
 295                 }
 296                 break;
 297
 298         case EV_SW:
 299                 if (is_event_supported(code, dev->swbit, SW_MAX) &&
 300                     !!test_bit(code, dev->sw) != !!value) {
 301
 302                         __change_bit(code, dev->sw);
 303                         disposition = INPUT_PASS_TO_HANDLERS;
 304                 }
 305                 break;
 306
 307         case EV_ABS:
 308                 if (is_event_supported(code, dev->absbit, ABS_MAX))
 309                         disposition = input_handle_abs_event(dev, code, &value);
 310
 311                 break;
 312
 313         case EV_REL:
 314                 if (is_event_supported(code, dev->relbit, REL_MAX) && value)
 315                         disposition = INPUT_PASS_TO_HANDLERS;
 316
 317                 break;
 318
 319         case EV_MSC:
 320                 if (is_event_supported(code, dev->mscbit, MSC_MAX))
 321                         disposition = INPUT_PASS_TO_ALL;
 322
 323                 break;
 324
 325         case EV_LED:
 326                 if (is_event_supported(code, dev->ledbit, LED_MAX) &&
 327                     !!test_bit(code, dev->led) != !!value) {
 328
 329                         __change_bit(code, dev->led);
 330                         disposition = INPUT_PASS_TO_ALL;
 331                 }
 332                 break;
 333
 334         case EV_SND:
 335                 if (is_event_supported(code, dev->sndbit, SND_MAX)) {
 336
 337                         if (!!test_bit(code, dev->snd) != !!value)
 338                                 __change_bit(code, dev->snd);
 339                         disposition = INPUT_PASS_TO_ALL;
 340                 }
 341                 break;
 342
 343         case EV_REP:
 344                 if (code <= REP_MAX && value >= 0 && dev->rep[code] != value) {
 345                         dev->rep[code] = value;
 346                         disposition = INPUT_PASS_TO_ALL;
 347                 }
 348                 break;
 349
 350         case EV_FF:
 351                 if (value >= 0)
 352                         disposition = INPUT_PASS_TO_ALL;
 353                 break;
 354
 355         case EV_PWR:
 356                 disposition = INPUT_PASS_TO_ALL;
 357                 break;
 358         }
 359
 360         return disposition;
 361 }
 362
 363 static void input_handle_event(struct input_dev *dev,
 364                                unsigned int type, unsigned int code, int value)
 365 {
 366         int disposition;
 367
 368         disposition = input_get_disposition(dev, type, code, value);
 369
 370         if ((disposition & INPUT_PASS_TO_DEVICE) && dev->event)
 371                 dev->event(dev, type, code, value);
 372
 373         if (!dev->vals)
 374                 return;
 375
 376         if (disposition & INPUT_PASS_TO_HANDLERS) {
 377                 struct input_value *v;
 378
 379                 if (disposition & INPUT_SLOT) {
 380                         v = &dev->vals[dev->num_vals++];
 381                         v->type = EV_ABS;
 382                         v->code = ABS_MT_SLOT;
 383                         v->value = dev->mt->slot;
 384                 }
 385
 386                 v = &dev->vals[dev->num_vals++];
 387                 v->type = type;
 388                 v->code = code;
 389                 v->value = value;
 390         }
 391
 392         if (disposition & INPUT_FLUSH) {
 393                 if (dev->num_vals >= 2)
 394                         input_pass_values(dev, dev->vals, dev->num_vals);
 395                 dev->num_vals = 0;
 396         } else if (dev->num_vals >= dev->max_vals - 2) {
 397                 dev->vals[dev->num_vals++] = input_value_sync;
 398                 input_pass_values(dev, dev->vals, dev->num_vals);
 399                 dev->num_vals = 0;
 400         }
 401
 402 }
 403
 404 /**
 405  * input_event() - report new input event
 406  * @dev: device that generated the event
 407  * @type: type of the event
 408  * @code: event code
 409  * @value: value of the event
 410  *
 411  * This function should be used by drivers implementing various input
 412  * devices to report input events. See also input_inject_event().
 413  *
 414  * NOTE: input_event() may be safely used right after input device was
 415  * allocated with input_allocate_device(), even before it is registered
 416  * with input_register_device(), but the event will not reach any of the
 417  * input handlers. Such early invocation of input_event() may be used
 418  * to 'seed' initial state of a switch or initial position of absolute
 419  * axis, etc.
 420  */
 421 void input_event(struct input_dev *dev,
 422                  unsigned int type, unsigned int code, int value)
 423 {
 424         unsigned long flags;
 425
 426         if (is_event_supported(type, dev->evbit, EV_MAX)) {
 427
 428                 spin_lock_irqsave(&dev->event_lock, flags);
 429                 input_handle_event(dev, type, code, value);
 430                 spin_unlock_irqrestore(&dev->event_lock, flags);
 431         }
 432 }
 433 EXPORT_SYMBOL(input_event);
 434
 435 /**
 436  * input_inject_event() - send input event from input handler
 437  * @handle: input handle to send event through
 438  * @type: type of the event
 439  * @code: event code
 440  * @value: value of the event
 441  *
 442  * Similar to input_event() but will ignore event if device is
 443  * "grabbed" and handle injecting event is not the one that owns
 444  * the device.
 445  */
 446 void input_inject_event(struct input_handle *handle,
 447                         unsigned int type, unsigned int code, int value)
 448 {
 449         struct input_dev *dev = handle->dev;
 450         struct input_handle *grab;
 451         unsigned long flags;
 452
 453         if (is_event_supported(type, dev->evbit, EV_MAX)) {
 454                 spin_lock_irqsave(&dev->event_lock, flags);
 455
 456                 rcu_read_lock();
 457                 grab = rcu_dereference(dev->grab);
 458                 if (!grab || grab == handle)
 459                         input_handle_event(dev, type, code, value);
 460                 rcu_read_unlock();
 461
 462                 spin_unlock_irqrestore(&dev->event_lock, flags);
 463         }
 464 }
 465 EXPORT_SYMBOL(input_inject_event);
 466
 467 /**
 468  * input_alloc_absinfo - allocates array of input_absinfo structs
 469  * @dev: the input device emitting absolute events
 470  *
 471  * If the absinfo struct the caller asked for is already allocated, this
 472  * functions will not do anything.
 473  */
 474 void input_alloc_absinfo(struct input_dev *dev)
 475 {
 476         if (!dev->absinfo)
 477                 dev->absinfo = kcalloc(ABS_CNT, sizeof(struct input_absinfo),
 478                                         GFP_KERNEL);
 479
 480         WARN(!dev->absinfo, "%s(): kcalloc() failed?\n", __func__);
 481 }
 482 EXPORT_SYMBOL(input_alloc_absinfo);
 483
 484 void input_set_abs_params(struct input_dev *dev, unsigned int axis,
 485                           int min, int max, int fuzz, int flat)
 486 {
 487         struct input_absinfo *absinfo;
 488
 489         input_alloc_absinfo(dev);
 490         if (!dev->absinfo)
 491                 return;
 492
 493         absinfo = &dev->absinfo[axis];
 494         absinfo->minimum = min;
 495         absinfo->maximum = max;
 496         absinfo->fuzz = fuzz;
 497         absinfo->flat = flat;
 498
 499         dev->absbit[BIT_WORD(axis)] |= BIT_MASK(axis);
 500 }
 501 EXPORT_SYMBOL(input_set_abs_params);
 502
 503
 504 /**
 505  * input_grab_device - grabs device for exclusive use
 506  * @handle: input handle that wants to own the device
 507  *
 508  * When a device is grabbed by an input handle all events generated by
 509  * the device are delivered only to this handle. Also events injected
 510  * by other input handles are ignored while device is grabbed.
 511  */
 512 int input_grab_device(struct input_handle *handle)
 513 {
 514         struct input_dev *dev = handle->dev;
 515         int retval;
 516
 517         retval = mutex_lock_interruptible(&dev->mutex);
 518         if (retval)
 519                 return retval;
 520
 521         if (dev->grab) {
 522                 retval = -EBUSY;
 523                 goto out;
 524         }
 525
 526         rcu_assign_pointer(dev->grab, handle);
 527
 528  out:
 529         mutex_unlock(&dev->mutex);
 530         return retval;
 531 }
 532 EXPORT_SYMBOL(input_grab_device);
 533
 534 static void __input_release_device(struct input_handle *handle)
 535 {
 536         struct input_dev *dev = handle->dev;
 537
 538         if (dev->grab == handle) {
 539                 rcu_assign_pointer(dev->grab, NULL);
 540                 /* Make sure input_pass_event() notices that grab is gone */
 541                 synchronize_rcu();
 542
 543                 list_for_each_entry(handle, &dev->h_list, d_node)
 544                         if (handle->open && handle->handler->start)
 545                                 handle->handler->start(handle);
 546         }
 547 }
 548
 549 /**
 550  * input_release_device - release previously grabbed device
 551  * @handle: input handle that owns the device
 552  *
 553  * Releases previously grabbed device so that other input handles can
 554  * start receiving input events. Upon release all handlers attached
 555  * to the device have their start() method called so they have a change
 556  * to synchronize device state with the rest of the system.
 557  */
 558 void input_release_device(struct input_handle *handle)
 559 {
 560         struct input_dev *dev = handle->dev;
 561
 562         mutex_lock(&dev->mutex);
 563         __input_release_device(handle);
 564         mutex_unlock(&dev->mutex);
 565 }
 566 EXPORT_SYMBOL(input_release_device);
 567
 568 /**
 569  * input_open_device - open input device
 570  * @handle: handle through which device is being accessed
 571  *
 572  * This function should be called by input handlers when they
 573  * want to start receive events from given input device.
 574  */
 575 int input_open_device(struct input_handle *handle)
 576 {
 577         struct input_dev *dev = handle->dev;
 578         int retval;
 579
 580         retval = mutex_lock_interruptible(&dev->mutex);
 581         if (retval)
 582                 return retval;
 583
 584         if (dev->going_away) {
 585                 retval = -ENODEV;
 586                 goto out;
 587         }
 588
 589         handle->open++;
 590
 591         if (!dev->users++ && dev->open)
 592                 retval = dev->open(dev);
 593
 594         if (retval) {
 595                 dev->users--;
 596                 if (!--handle->open) {
 597                         /*
 598                          * Make sure we are not delivering any more events
 599                          * through this handle
 600                          */
 601                         synchronize_rcu();
 602                 }
 603         }
 604
 605  out:
 606         mutex_unlock(&dev->mutex);
 607         return retval;
 608 }
 609 EXPORT_SYMBOL(input_open_device);
 610
 611 int input_flush_device(struct input_handle *handle, struct file *file)
 612 {
 613         struct input_dev *dev = handle->dev;
 614         int retval;
 615
 616         retval = mutex_lock_interruptible(&dev->mutex);
 617         if (retval)
 618                 return retval;
 619
 620         if (dev->flush)
 621                 retval = dev->flush(dev, file);
 622
 623         mutex_unlock(&dev->mutex);
 624         return retval;
 625 }
 626 EXPORT_SYMBOL(input_flush_device);
 627
 628 /**
 629  * input_close_device - close input device
 630  * @handle: handle through which device is being accessed
 631  *
 632  * This function should be called by input handlers when they
 633  * want to stop receive events from given input device.
 634  */
 635 void input_close_device(struct input_handle *handle)
 636 {
 637         struct input_dev *dev = handle->dev;
 638
 639         mutex_lock(&dev->mutex);
 640
 641         __input_release_device(handle);
 642
 643         if (!--dev->users && dev->close)
 644                 dev->close(dev);
 645
 646         if (!--handle->open) {
 647                 /*
 648                  * synchronize_rcu() makes sure that input_pass_event()
 649                  * completed and that no more input events are delivered
 650                  * through this handle
 651                  */
 652                 synchronize_rcu();
 653         }
 654
 655         mutex_unlock(&dev->mutex);
 656 }
 657 EXPORT_SYMBOL(input_close_device);
 658
 659 /*
 660  * Simulate keyup events for all keys that are marked as pressed.
 661  * The function must be called with dev->event_lock held.
 662  */
 663 static void input_dev_release_keys(struct input_dev *dev)
 664 {
 665         int code;
 666
 667         if (is_event_supported(EV_KEY, dev->evbit, EV_MAX)) {
 668                 for (code = 0; code <= KEY_MAX; code++) {
 669                         if (is_event_supported(code, dev->keybit, KEY_MAX) &&
 670                             __test_and_clear_bit(code, dev->key)) {
 671                                 input_pass_event(dev, EV_KEY, code, 0);
 672                         }
 673                 }
 674                 input_pass_event(dev, EV_SYN, SYN_REPORT, 1);
 675         }
 676 }
 677
 678 /*
 679  * Prepare device for unregistering
 680  */
 681 static void input_disconnect_device(struct input_dev *dev)
 682 {
 683         struct input_handle *handle;
 684
 685         /*
 686          * Mark device as going away. Note that we take dev->mutex here
 687          * not to protect access to dev->going_away but rather to ensure
 688          * that there are no threads in the middle of input_open_device()
 689          */
 690         mutex_lock(&dev->mutex);
 691         dev->going_away = true;
 692         mutex_unlock(&dev->mutex);
 693
 694         spin_lock_irq(&dev->event_lock);
 695
 696         /*
 697          * Simulate keyup events for all pressed keys so that handlers
 698          * are not left with "stuck" keys. The driver may continue
 699          * generate events even after we done here but they will not
 700          * reach any handlers.
 701          */
 702         input_dev_release_keys(dev);
 703
 704         list_for_each_entry(handle, &dev->h_list, d_node)
 705                 handle->open = 0;
 706
 707         spin_unlock_irq(&dev->event_lock);
 708 }
 709
 710 /**
 711  * input_scancode_to_scalar() - converts scancode in &struct input_keymap_entry
 712  * @ke: keymap entry containing scancode to be converted.
 713  * @scancode: pointer to the location where converted scancode should
 714  *      be stored.
 715  *
 716  * This function is used to convert scancode stored in &struct keymap_entry
 717  * into scalar form understood by legacy keymap handling methods. These
 718  * methods expect scancodes to be represented as 'unsigned int'.
 719  */
 720 int input_scancode_to_scalar(const struct input_keymap_entry *ke,
 721                              unsigned int *scancode)
 722 {
 723         switch (ke->len) {
 724         case 1:
 725                 *scancode = *((u8 *)ke->scancode);
 726                 break;
 727
 728         case 2:
 729                 *scancode = *((u16 *)ke->scancode);
 730                 break;
 731
 732         case 4:
 733                 *scancode = *((u32 *)ke->scancode);
 734                 break;
 735
 736         default:
 737                 return -EINVAL;
 738         }
 739
 740         return 0;
 741 }
 742 EXPORT_SYMBOL(input_scancode_to_scalar);
 743
 744 /*
 745  * Those routines handle the default case where no [gs]etkeycode() is
 746  * defined. In this case, an array indexed by the scancode is used.
 747  */
 748
 749 static unsigned int input_fetch_keycode(struct input_dev *dev,
 750                                         unsigned int index)
 751 {
 752         switch (dev->keycodesize) {
 753         case 1:
 754                 return ((u8 *)dev->keycode)[index];
 755
 756         case 2:
 757                 return ((u16 *)dev->keycode)[index];
 758
 759         default:
 760                 return ((u32 *)dev->keycode)[index];
 761         }
 762 }
 763
 764 static int input_default_getkeycode(struct input_dev *dev,
 765                                     struct input_keymap_entry *ke)
 766 {
 767         unsigned int index;
 768         int error;
 769
 770         if (!dev->keycodesize)
 771                 return -EINVAL;
 772
 773         if (ke->flags & INPUT_KEYMAP_BY_INDEX)
 774                 index = ke->index;
 775         else {
 776                 error = input_scancode_to_scalar(ke, &index);
 777                 if (error)
 778                         return error;
 779         }
 780
 781         if (index >= dev->keycodemax)
 782                 return -EINVAL;
 783
 784         ke->keycode = input_fetch_keycode(dev, index);
 785         ke->index = index;
 786         ke->len = sizeof(index);
 787         memcpy(ke->scancode, &index, sizeof(index));
 788
 789         return 0;
 790 }
 791
 792 static int input_default_setkeycode(struct input_dev *dev,
 793                                     const struct input_keymap_entry *ke,
 794                                     unsigned int *old_keycode)
 795 {
 796         unsigned int index;
 797         int error;
 798         int i;
 799
 800         if (!dev->keycodesize)
 801                 return -EINVAL;
 802
 803         if (ke->flags & INPUT_KEYMAP_BY_INDEX) {
 804                 index = ke->index;
 805         } else {
 806                 error = input_scancode_to_scalar(ke, &index);
 807                 if (error)
 808                         return error;
 809         }
 810
 811         if (index >= dev->keycodemax)
 812                 return -EINVAL;
 813
 814         if (dev->keycodesize < sizeof(ke->keycode) &&
 815                         (ke->keycode >> (dev->keycodesize * 8)))
 816                 return -EINVAL;
 817
 818         switch (dev->keycodesize) {
 819                 case 1: {
 820                         u8 *k = (u8 *)dev->keycode;
 821                         *old_keycode = k[index];
 822                         k[index] = ke->keycode;
 823                         break;
 824                 }
 825                 case 2: {
 826                         u16 *k = (u16 *)dev->keycode;
 827                         *old_keycode = k[index];
 828                         k[index] = ke->keycode;
 829                         break;
 830                 }
 831                 default: {
 832                         u32 *k = (u32 *)dev->keycode;
 833                         *old_keycode = k[index];
 834                         k[index] = ke->keycode;
 835                         break;
 836                 }
 837         }
 838
 839         __clear_bit(*old_keycode, dev->keybit);
 840         __set_bit(ke->keycode, dev->keybit);
 841
 842         for (i = 0; i < dev->keycodemax; i++) {
 843                 if (input_fetch_keycode(dev, i) == *old_keycode) {
 844                         __set_bit(*old_keycode, dev->keybit);
 845                         break; /* Setting the bit twice is useless, so break */
 846                 }
 847         }
 848
 849         return 0;
 850 }
 851
 852 /**
 853  * input_get_keycode - retrieve keycode currently mapped to a given scancode
 854  * @dev: input device which keymap is being queried
 855  * @ke: keymap entry
 856  *
 857  * This function should be called by anyone interested in retrieving current
 858  * keymap. Presently evdev handlers use it.
 859  */
 860 int input_get_keycode(struct input_dev *dev, struct input_keymap_entry *ke)
 861 {
 862         unsigned long flags;
 863         int retval;
 864
 865         spin_lock_irqsave(&dev->event_lock, flags);
 866         retval = dev->getkeycode(dev, ke);
 867         spin_unlock_irqrestore(&dev->event_lock, flags);
 868
 869         return retval;
 870 }
 871 EXPORT_SYMBOL(input_get_keycode);
 872
 873 /**
 874  * input_set_keycode - attribute a keycode to a given scancode
 875  * @dev: input device which keymap is being updated
 876  * @ke: new keymap entry
 877  *
 878  * This function should be called by anyone needing to update current
 879  * keymap. Presently keyboard and evdev handlers use it.
 880  */
 881 int input_set_keycode(struct input_dev *dev,
 882                       const struct input_keymap_entry *ke)
 883 {
 884         unsigned long flags;
 885         unsigned int old_keycode;
 886         int retval;
 887
 888         if (ke->keycode > KEY_MAX)
 889                 return -EINVAL;
 890
 891         spin_lock_irqsave(&dev->event_lock, flags);
 892
 893         retval = dev->setkeycode(dev, ke, &old_keycode);
 894         if (retval)
 895                 goto out;
 896
 897         /* Make sure KEY_RESERVED did not get enabled. */
 898         __clear_bit(KEY_RESERVED, dev->keybit);
 899
 900         /*
 901          * Simulate keyup event if keycode is not present
 902          * in the keymap anymore
 903          */
 904         if (test_bit(EV_KEY, dev->evbit) &&
 905             !is_event_supported(old_keycode, dev->keybit, KEY_MAX) &&
 906             __test_and_clear_bit(old_keycode, dev->key)) {
 907                 struct input_value vals[] =  {
 908                         { EV_KEY, old_keycode, 0 },
 909                         input_value_sync
 910                 };
 911
 912                 input_pass_values(dev, vals, ARRAY_SIZE(vals));
 913         }
 914
 915  out:
 916         spin_unlock_irqrestore(&dev->event_lock, flags);
 917
 918         return retval;
 919 }
 920 EXPORT_SYMBOL(input_set_keycode);
 921
 922 static const struct input_device_id *input_match_device(struct input_handler *handler,
 923                                                         struct input_dev *dev)
 924 {
 925         const struct input_device_id *id;
 926
 927         for (id = handler->id_table; id->flags || id->driver_info; id++) {
 928
 929                 if (id->flags & INPUT_DEVICE_ID_MATCH_BUS)
 930                         if (id->bustype != dev->id.bustype)
 931                                 continue;
 932
 933                 if (id->flags & INPUT_DEVICE_ID_MATCH_VENDOR)
 934                         if (id->vendor != dev->id.vendor)
 935                                 continue;
 936
 937                 if (id->flags & INPUT_DEVICE_ID_MATCH_PRODUCT)
 938                         if (id->product != dev->id.product)
 939                                 continue;
 940
 941                 if (id->flags & INPUT_DEVICE_ID_MATCH_VERSION)
 942                         if (id->version != dev->id.version)
 943                                 continue;
 944
 945                 if (!bitmap_subset(id->evbit, dev->evbit, EV_MAX))
 946                         continue;
 947
 948                 if (!bitmap_subset(id->keybit, dev->keybit, KEY_MAX))
 949                         continue;
 950
 951                 if (!bitmap_subset(id->relbit, dev->relbit, REL_MAX))
 952                         continue;
 953
 954                 if (!bitmap_subset(id->absbit, dev->absbit, ABS_MAX))
 955                         continue;
 956
 957                 if (!bitmap_subset(id->mscbit, dev->mscbit, MSC_MAX))
 958                         continue;
 959
 960                 if (!bitmap_subset(id->ledbit, dev->ledbit, LED_MAX))
 961                         continue;
 962
 963                 if (!bitmap_subset(id->sndbit, dev->sndbit, SND_MAX))
 964                         continue;
 965
 966                 if (!bitmap_subset(id->ffbit, dev->ffbit, FF_MAX))
 967                         continue;
 968
 969                 if (!bitmap_subset(id->swbit, dev->swbit, SW_MAX))
 970                         continue;
 971
 972                 if (!handler->match || handler->match(handler, dev))
 973                         return id;
 974         }
 975
 976         return NULL;
 977 }
 978
 979 static int input_attach_handler(struct input_dev *dev, struct input_handler *handler)
 980 {
 981         const struct input_device_id *id;
 982         int error;
 983
 984         id = input_match_device(handler, dev);
 985         if (!id)
 986                 return -ENODEV;
 987
 988         error = handler->connect(handler, dev, id);
 989         if (error && error != -ENODEV)
 990                 pr_err("failed to attach handler %s to device %s, error: %d\n",
 991                        handler->name, kobject_name(&dev->dev.kobj), error);
 992
 993         return error;
 994 }
 995
 996 #ifdef CONFIG_COMPAT
 997
 998 static int input_bits_to_string(char *buf, int buf_size,
 999                                 unsigned long bits, bool skip_empty)
1000 {
1001         int len = 0;
1002
1003         if (INPUT_COMPAT_TEST) {
1004                 u32 dword = bits >> 32;
1005                 if (dword || !skip_empty)
1006                         len += snprintf(buf, buf_size, "%x ", dword);
1007
1008                 dword = bits & 0xffffffffUL;
1009                 if (dword || !skip_empty || len)
1010                         len += snprintf(buf + len, max(buf_size - len, 0),
1011                                         "%x", dword);
1012         } else {
1013                 if (bits || !skip_empty)
1014                         len += snprintf(buf, buf_size, "%lx", bits);
1015         }
1016
1017         return len;
1018 }
1019
1020 #else /* !CONFIG_COMPAT */
1021
1022 static int input_bits_to_string(char *buf, int buf_size,
1023                                 unsigned long bits, bool skip_empty)
1024 {
1025         return bits || !skip_empty ?
1026                 snprintf(buf, buf_size, "%lx", bits) : 0;
1027 }
1028
1029 #endif
1030
1031 #ifdef CONFIG_PROC_FS
1032
1033 static struct proc_dir_entry *proc_bus_input_dir;
1034 static DECLARE_WAIT_QUEUE_HEAD(input_devices_poll_wait);
1035 static int input_devices_state;
1036
1037 static inline void input_wakeup_procfs_readers(void)
1038 {
1039         input_devices_state++;
1040         wake_up(&input_devices_poll_wait);
1041 }
1042
1043 static unsigned int input_proc_devices_poll(struct file *file, poll_table *wait)
1044 {
1045         poll_wait(file, &input_devices_poll_wait, wait);
1046         if (file->f_version != input_devices_state) {
1047                 file->f_version = input_devices_state;
1048                 return POLLIN | POLLRDNORM;
1049         }
1050
1051         return 0;
1052 }
1053
1054 union input_seq_state {
1055         struct {
1056                 unsigned short pos;
1057                 bool mutex_acquired;
1058         };
1059         void *p;
1060 };
1061
1062 static void *input_devices_seq_start(struct seq_file *seq, loff_t *pos)
1063 {
1064         union input_seq_state *state = (union input_seq_state *)&seq->private;
1065         int error;
1066
1067         /* We need to fit into seq->private pointer */
1068         BUILD_BUG_ON(sizeof(union input_seq_state) != sizeof(seq->private));
1069
1070         error = mutex_lock_interruptible(&input_mutex);
1071         if (error) {
1072                 state->mutex_acquired = false;
1073                 return ERR_PTR(error);
1074         }
1075
1076         state->mutex_acquired = true;
1077
1078         return seq_list_start(&input_dev_list, *pos);
1079 }
1080
1081 static void *input_devices_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1082 {
1083         return seq_list_next(v, &input_dev_list, pos);
1084 }
1085
1086 static void input_seq_stop(struct seq_file *seq, void *v)
1087 {
1088         union input_seq_state *state = (union input_seq_state *)&seq->private;
1089
1090         if (state->mutex_acquired)
1091                 mutex_unlock(&input_mutex);
1092 }
1093
1094 static void input_seq_print_bitmap(struct seq_file *seq, const char *name,
1095                                    unsigned long *bitmap, int max)
1096 {
1097         int i;
1098         bool skip_empty = true;
1099         char buf[18];
1100
1101         seq_printf(seq, "B: %s=", name);
1102
1103         for (i = BITS_TO_LONGS(max) - 1; i >= 0; i--) {
1104                 if (input_bits_to_string(buf, sizeof(buf),
1105                                          bitmap[i], skip_empty)) {
1106                         skip_empty = false;
1107                         seq_printf(seq, "%s%s", buf, i > 0 ? " " : "");
1108                 }
1109         }
1110
1111         /*
1112          * If no output was produced print a single 0.
1113          */
1114         if (skip_empty)
1115                 seq_puts(seq, "0");
1116
1117         seq_putc(seq, '\n');
1118 }
1119
1120 static int input_devices_seq_show(struct seq_file *seq, void *v)
1121 {
1122         struct input_dev *dev = container_of(v, struct input_dev, node);
1123         const char *path = kobject_get_path(&dev->dev.kobj, GFP_KERNEL);
1124         struct input_handle *handle;
1125
1126         seq_printf(seq, "I: Bus=%04x Vendor=%04x Product=%04x Version=%04x\n",
1127                    dev->id.bustype, dev->id.vendor, dev->id.product, dev->id.version);
1128
1129         seq_printf(seq, "N: Name=\"%s\"\n", dev->name ? dev->name : "");
1130         seq_printf(seq, "P: Phys=%s\n", dev->phys ? dev->phys : "");
1131         seq_printf(seq, "S: Sysfs=%s\n", path ? path : "");
1132         seq_printf(seq, "U: Uniq=%s\n", dev->uniq ? dev->uniq : "");
1133         seq_printf(seq, "H: Handlers=");
1134
1135         list_for_each_entry(handle, &dev->h_list, d_node)
1136                 seq_printf(seq, "%s ", handle->name);
1137         seq_putc(seq, '\n');
1138
1139         input_seq_print_bitmap(seq, "PROP", dev->propbit, INPUT_PROP_MAX);
1140
1141         input_seq_print_bitmap(seq, "EV", dev->evbit, EV_MAX);
1142         if (test_bit(EV_KEY, dev->evbit))
1143                 input_seq_print_bitmap(seq, "KEY", dev->keybit, KEY_MAX);
1144         if (test_bit(EV_REL, dev->evbit))
1145                 input_seq_print_bitmap(seq, "REL", dev->relbit, REL_MAX);
1146         if (test_bit(EV_ABS, dev->evbit))
1147                 input_seq_print_bitmap(seq, "ABS", dev->absbit, ABS_MAX);
1148         if (test_bit(EV_MSC, dev->evbit))
1149                 input_seq_print_bitmap(seq, "MSC", dev->mscbit, MSC_MAX);
1150         if (test_bit(EV_LED, dev->evbit))
1151                 input_seq_print_bitmap(seq, "LED", dev->ledbit, LED_MAX);
1152         if (test_bit(EV_SND, dev->evbit))
1153                 input_seq_print_bitmap(seq, "SND", dev->sndbit, SND_MAX);
1154         if (test_bit(EV_FF, dev->evbit))
1155                 input_seq_print_bitmap(seq, "FF", dev->ffbit, FF_MAX);
1156         if (test_bit(EV_SW, dev->evbit))
1157                 input_seq_print_bitmap(seq, "SW", dev->swbit, SW_MAX);
1158
1159         seq_putc(seq, '\n');
1160
1161         kfree(path);
1162         return 0;
1163 }
1164
1165 static const struct seq_operations input_devices_seq_ops = {
1166         .start  = input_devices_seq_start,
1167         .next   = input_devices_seq_next,
1168         .stop   = input_seq_stop,
1169         .show   = input_devices_seq_show,
1170 };
1171
1172 static int input_proc_devices_open(struct inode *inode, struct file *file)
1173 {
1174         return seq_open(file, &input_devices_seq_ops);
1175 }
1176
1177 static const struct file_operations input_devices_fileops = {
1178         .owner          = THIS_MODULE,
1179         .open           = input_proc_devices_open,
1180         .poll           = input_proc_devices_poll,
1181         .read           = seq_read,
1182         .llseek         = seq_lseek,
1183         .release        = seq_release,
1184 };
1185
1186 static void *input_handlers_seq_start(struct seq_file *seq, loff_t *pos)
1187 {
1188         union input_seq_state *state = (union input_seq_state *)&seq->private;
1189         int error;
1190
1191         /* We need to fit into seq->private pointer */
1192         BUILD_BUG_ON(sizeof(union input_seq_state) != sizeof(seq->private));
1193
1194         error = mutex_lock_interruptible(&input_mutex);
1195         if (error) {
1196                 state->mutex_acquired = false;
1197                 return ERR_PTR(error);
1198         }
1199
1200         state->mutex_acquired = true;
1201         state->pos = *pos;
1202
1203         return seq_list_start(&input_handler_list, *pos);
1204 }
1205
1206 static void *input_handlers_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1207 {
1208         union input_seq_state *state = (union input_seq_state *)&seq->private;
1209
1210         state->pos = *pos + 1;
1211         return seq_list_next(v, &input_handler_list, pos);
1212 }
1213
1214 static int input_handlers_seq_show(struct seq_file *seq, void *v)
1215 {
1216         struct input_handler *handler = container_of(v, struct input_handler, node);
1217         union input_seq_state *state = (union input_seq_state *)&seq->private;
1218
1219         seq_printf(seq, "N: Number=%u Name=%s", state->pos, handler->name);
1220         if (handler->filter)
1221                 seq_puts(seq, " (filter)");
1222         if (handler->legacy_minors)
1223                 seq_printf(seq, " Minor=%d", handler->minor);
1224         seq_putc(seq, '\n');
1225
1226         return 0;
1227 }
1228
1229 static const struct seq_operations input_handlers_seq_ops = {
1230         .start  = input_handlers_seq_start,
1231         .next   = input_handlers_seq_next,
1232         .stop   = input_seq_stop,
1233         .show   = input_handlers_seq_show,
1234 };
1235
1236 static int input_proc_handlers_open(struct inode *inode, struct file *file)
1237 {
1238         return seq_open(file, &input_handlers_seq_ops);
1239 }
1240
1241 static const struct file_operations input_handlers_fileops = {
1242         .owner          = THIS_MODULE,
1243         .open           = input_proc_handlers_open,
1244         .read           = seq_read,
1245         .llseek         = seq_lseek,
1246         .release        = seq_release,
1247 };
1248
1249 static int __init input_proc_init(void)
1250 {
1251         struct proc_dir_entry *entry;
1252
1253         proc_bus_input_dir = proc_mkdir("bus/input", NULL);
1254         if (!proc_bus_input_dir)
1255                 return -ENOMEM;
1256
1257         entry = proc_create("devices", 0, proc_bus_input_dir,
1258                             &input_devices_fileops);
1259         if (!entry)
1260                 goto fail1;
1261
1262         entry = proc_create("handlers", 0, proc_bus_input_dir,
1263                             &input_handlers_fileops);
1264         if (!entry)
1265                 goto fail2;
1266
1267         return 0;
1268
1269  fail2: remove_proc_entry("devices", proc_bus_input_dir);
1270  fail1: remove_proc_entry("bus/input", NULL);
1271         return -ENOMEM;
1272 }
1273
1274 static void input_proc_exit(void)
1275 {
1276         remove_proc_entry("devices", proc_bus_input_dir);
1277         remove_proc_entry("handlers", proc_bus_input_dir);
1278         remove_proc_entry("bus/input", NULL);
1279 }
1280
1281 #else /* !CONFIG_PROC_FS */
1282 static inline void input_wakeup_procfs_readers(void) { }
1283 static inline int input_proc_init(void) { return 0; }
1284 static inline void input_proc_exit(void) { }
1285 #endif
1286
1287 #define INPUT_DEV_STRING_ATTR_SHOW(name)                                \
1288 static ssize_t input_dev_show_##name(struct device *dev,                \
1289                                      struct device_attribute *attr,     \
1290                                      char *buf)                         \
1291 {                                                                       \
1292         struct input_dev *input_dev = to_input_dev(dev);                \
1293                                                                         \
1294         return scnprintf(buf, PAGE_SIZE, "%s\n",                        \
1295                          input_dev->name ? input_dev->name : "");       \
1296 }                                                                       \
1297 static DEVICE_ATTR(name, S_IRUGO, input_dev_show_##name, NULL)
1298
1299 INPUT_DEV_STRING_ATTR_SHOW(name);
1300 INPUT_DEV_STRING_ATTR_SHOW(phys);
1301 INPUT_DEV_STRING_ATTR_SHOW(uniq);
1302
1303 static int input_print_modalias_bits(char *buf, int size,
1304                                      char name, unsigned long *bm,
1305                                      unsigned int min_bit, unsigned int max_bit)
1306 {
1307         int len = 0, i;
1308
1309         len += snprintf(buf, max(size, 0), "%c", name);
1310         for (i = min_bit; i < max_bit; i++)
1311                 if (bm[BIT_WORD(i)] & BIT_MASK(i))
1312                         len += snprintf(buf + len, max(size - len, 0), "%X,", i);
1313         return len;
1314 }
1315
1316 static int input_print_modalias(char *buf, int size, struct input_dev *id,
1317                                 int add_cr)
1318 {
1319         int len;
1320
1321         len = snprintf(buf, max(size, 0),
1322                        "input:b%04Xv%04Xp%04Xe%04X-",
1323                        id->id.bustype, id->id.vendor,
1324                        id->id.product, id->id.version);
1325
1326         len += input_print_modalias_bits(buf + len, size - len,
1327                                 'e', id->evbit, 0, EV_MAX);
1328         len += input_print_modalias_bits(buf + len, size - len,
1329                                 'k', id->keybit, KEY_MIN_INTERESTING, KEY_MAX);
1330         len += input_print_modalias_bits(buf + len, size - len,
1331                                 'r', id->relbit, 0, REL_MAX);
1332         len += input_print_modalias_bits(buf + len, size - len,
1333                                 'a', id->absbit, 0, ABS_MAX);
1334         len += input_print_modalias_bits(buf + len, size - len,
1335                                 'm', id->mscbit, 0, MSC_MAX);
1336         len += input_print_modalias_bits(buf + len, size - len,
1337                                 'l', id->ledbit, 0, LED_MAX);
1338         len += input_print_modalias_bits(buf + len, size - len,
1339                                 's', id->sndbit, 0, SND_MAX);
1340         len += input_print_modalias_bits(buf + len, size - len,
1341                                 'f', id->ffbit, 0, FF_MAX);
1342         len += input_print_modalias_bits(buf + len, size - len,
1343                                 'w', id->swbit, 0, SW_MAX);
1344
1345         if (add_cr)
1346                 len += snprintf(buf + len, max(size - len, 0), "\n");
1347
1348         return len;
1349 }
1350
1351 static ssize_t input_dev_show_modalias(struct device *dev,
1352                                        struct device_attribute *attr,
1353                                        char *buf)
1354 {
1355         struct input_dev *id = to_input_dev(dev);
1356         ssize_t len;
1357
1358         len = input_print_modalias(buf, PAGE_SIZE, id, 1);
1359
1360         return min_t(int, len, PAGE_SIZE);
1361 }
1362 static DEVICE_ATTR(modalias, S_IRUGO, input_dev_show_modalias, NULL);
1363
1364 static int input_print_bitmap(char *buf, int buf_size, unsigned long *bitmap,
1365                               int max, int add_cr);
1366
1367 static ssize_t input_dev_show_properties(struct device *dev,
1368                                          struct device_attribute *attr,
1369                                          char *buf)
1370 {
1371         struct input_dev *input_dev = to_input_dev(dev);
1372         int len = input_print_bitmap(buf, PAGE_SIZE, input_dev->propbit,
1373                                      INPUT_PROP_MAX, true);
1374         return min_t(int, len, PAGE_SIZE);
1375 }
1376 static DEVICE_ATTR(properties, S_IRUGO, input_dev_show_properties, NULL);
1377
1378 static struct attribute *input_dev_attrs[] = {
1379         &dev_attr_name.attr,
1380         &dev_attr_phys.attr,
1381         &dev_attr_uniq.attr,
1382         &dev_attr_modalias.attr,
1383         &dev_attr_properties.attr,
1384         NULL
1385 };
1386
1387 static struct attribute_group input_dev_attr_group = {
1388         .attrs  = input_dev_attrs,
1389 };
1390
1391 #define INPUT_DEV_ID_ATTR(name)                                         \
1392 static ssize_t input_dev_show_id_##name(struct device *dev,             \
1393                                         struct device_attribute *attr,  \
1394                                         char *buf)                      \
1395 {                                                                       \
1396         struct input_dev *input_dev = to_input_dev(dev);                \
1397         return scnprintf(buf, PAGE_SIZE, "%04x\n", input_dev->id.name); \
1398 }                                                                       \
1399 static DEVICE_ATTR(name, S_IRUGO, input_dev_show_id_##name, NULL)
1400
1401 INPUT_DEV_ID_ATTR(bustype);
1402 INPUT_DEV_ID_ATTR(vendor);
1403 INPUT_DEV_ID_ATTR(product);
1404 INPUT_DEV_ID_ATTR(version);
1405
1406 static struct attribute *input_dev_id_attrs[] = {
1407         &dev_attr_bustype.attr,
1408         &dev_attr_vendor.attr,
1409         &dev_attr_product.attr,
1410         &dev_attr_version.attr,
1411         NULL
1412 };
1413
1414 static struct attribute_group input_dev_id_attr_group = {
1415         .name   = "id",
1416         .attrs  = input_dev_id_attrs,
1417 };
1418
1419 static int input_print_bitmap(char *buf, int buf_size, unsigned long *bitmap,
1420                               int max, int add_cr)
1421 {
1422         int i;
1423         int len = 0;
1424         bool skip_empty = true;
1425
1426         for (i = BITS_TO_LONGS(max) - 1; i >= 0; i--) {
1427                 len += input_bits_to_string(buf + len, max(buf_size - len, 0),
1428                                             bitmap[i], skip_empty);
1429                 if (len) {
1430                         skip_empty = false;
1431                         if (i > 0)
1432                                 len += snprintf(buf + len, max(buf_size - len, 0), " ");
1433                 }
1434         }
1435
1436         /*
1437          * If no output was produced print a single 0.
1438          */
1439         if (len == 0)
1440                 len = snprintf(buf, buf_size, "%d", 0);
1441
1442         if (add_cr)
1443                 len += snprintf(buf + len, max(buf_size - len, 0), "\n");
1444
1445         return len;
1446 }
1447
1448 #define INPUT_DEV_CAP_ATTR(ev, bm)                                      \
1449 static ssize_t input_dev_show_cap_##bm(struct device *dev,              \
1450                                        struct device_attribute *attr,   \
1451                                        char *buf)                       \
1452 {                                                                       \
1453         struct input_dev *input_dev = to_input_dev(dev);                \
1454         int len = input_print_bitmap(buf, PAGE_SIZE,                    \
1455                                      input_dev->bm##bit, ev##_MAX,      \
1456                                      true);                             \
1457         return min_t(int, len, PAGE_SIZE);                              \
1458 }                                                                       \
1459 static DEVICE_ATTR(bm, S_IRUGO, input_dev_show_cap_##bm, NULL)
1460
1461 INPUT_DEV_CAP_ATTR(EV, ev);
1462 INPUT_DEV_CAP_ATTR(KEY, key);
1463 INPUT_DEV_CAP_ATTR(REL, rel);
1464 INPUT_DEV_CAP_ATTR(ABS, abs);
1465 INPUT_DEV_CAP_ATTR(MSC, msc);
1466 INPUT_DEV_CAP_ATTR(LED, led);
1467 INPUT_DEV_CAP_ATTR(SND, snd);
1468 INPUT_DEV_CAP_ATTR(FF, ff);
1469 INPUT_DEV_CAP_ATTR(SW, sw);
1470
1471 static struct attribute *input_dev_caps_attrs[] = {
1472         &dev_attr_ev.attr,
1473         &dev_attr_key.attr,
1474         &dev_attr_rel.attr,
1475         &dev_attr_abs.attr,
1476         &dev_attr_msc.attr,
1477         &dev_attr_led.attr,
1478         &dev_attr_snd.attr,
1479         &dev_attr_ff.attr,
1480         &dev_attr_sw.attr,
1481         NULL
1482 };
1483
1484 static struct attribute_group input_dev_caps_attr_group = {
1485         .name   = "capabilities",
1486         .attrs  = input_dev_caps_attrs,
1487 };
1488
1489 static const struct attribute_group *input_dev_attr_groups[] = {
1490         &input_dev_attr_group,
1491         &input_dev_id_attr_group,
1492         &input_dev_caps_attr_group,
1493         NULL
1494 };
1495
1496 static void input_dev_release(struct device *device)
1497 {
1498         struct input_dev *dev = to_input_dev(device);
1499
1500         input_ff_destroy(dev);
1501         input_mt_destroy_slots(dev);
1502         kfree(dev->absinfo);
1503         kfree(dev->vals);
1504         kfree(dev);
1505
1506         module_put(THIS_MODULE);
1507 }
1508
1509 /*
1510  * Input uevent interface - loading event handlers based on
1511  * device bitfields.
1512  */
1513 static int input_add_uevent_bm_var(struct kobj_uevent_env *env,
1514                                    const char *name, unsigned long *bitmap, int max)
1515 {
1516         int len;
1517
1518         if (add_uevent_var(env, "%s", name))
1519                 return -ENOMEM;
1520
1521         len = input_print_bitmap(&env->buf[env->buflen - 1],
1522                                  sizeof(env->buf) - env->buflen,
1523                                  bitmap, max, false);
1524         if (len >= (sizeof(env->buf) - env->buflen))
1525                 return -ENOMEM;
1526
1527         env->buflen += len;
1528         return 0;
1529 }
1530
1531 static int input_add_uevent_modalias_var(struct kobj_uevent_env *env,
1532                                          struct input_dev *dev)
1533 {
1534         int len;
1535
1536         if (add_uevent_var(env, "MODALIAS="))
1537                 return -ENOMEM;
1538
1539         len = input_print_modalias(&env->buf[env->buflen - 1],
1540                                    sizeof(env->buf) - env->buflen,
1541                                    dev, 0);
1542         if (len >= (sizeof(env->buf) - env->buflen))
1543                 return -ENOMEM;
1544
1545         env->buflen += len;
1546         return 0;
1547 }
1548
1549 #define INPUT_ADD_HOTPLUG_VAR(fmt, val...)                              \
1550         do {                                                            \
1551                 int err = add_uevent_var(env, fmt, val);                \
1552                 if (err)                                                \
1553                         return err;                                     \
1554         } while (0)
1555
1556 #define INPUT_ADD_HOTPLUG_BM_VAR(name, bm, max)                         \
1557         do {                                                            \
1558                 int err = input_add_uevent_bm_var(env, name, bm, max);  \
1559                 if (err)                                                \
1560                         return err;                                     \
1561         } while (0)
1562
1563 #define INPUT_ADD_HOTPLUG_MODALIAS_VAR(dev)                             \
1564         do {                                                            \
1565                 int err = input_add_uevent_modalias_var(env, dev);      \
1566                 if (err)                                                \
1567                         return err;                                     \
1568         } while (0)
1569
1570 static int input_dev_uevent(struct device *device, struct kobj_uevent_env *env)
1571 {
1572         struct input_dev *dev = to_input_dev(device);
1573
1574         INPUT_ADD_HOTPLUG_VAR("PRODUCT=%x/%x/%x/%x",
1575                                 dev->id.bustype, dev->id.vendor,
1576                                 dev->id.product, dev->id.version);
1577         if (dev->name)
1578                 INPUT_ADD_HOTPLUG_VAR("NAME=\"%s\"", dev->name);
1579         if (dev->phys)
1580                 INPUT_ADD_HOTPLUG_VAR("PHYS=\"%s\"", dev->phys);
1581         if (dev->uniq)
1582                 INPUT_ADD_HOTPLUG_VAR("UNIQ=\"%s\"", dev->uniq);
1583
1584         INPUT_ADD_HOTPLUG_BM_VAR("PROP=", dev->propbit, INPUT_PROP_MAX);
1585
1586         INPUT_ADD_HOTPLUG_BM_VAR("EV=", dev->evbit, EV_MAX);
1587         if (test_bit(EV_KEY, dev->evbit))
1588                 INPUT_ADD_HOTPLUG_BM_VAR("KEY=", dev->keybit, KEY_MAX);
1589         if (test_bit(EV_REL, dev->evbit))
1590                 INPUT_ADD_HOTPLUG_BM_VAR("REL=", dev->relbit, REL_MAX);
1591         if (test_bit(EV_ABS, dev->evbit))
1592                 INPUT_ADD_HOTPLUG_BM_VAR("ABS=", dev->absbit, ABS_MAX);
1593         if (test_bit(EV_MSC, dev->evbit))
1594                 INPUT_ADD_HOTPLUG_BM_VAR("MSC=", dev->mscbit, MSC_MAX);
1595         if (test_bit(EV_LED, dev->evbit))
1596                 INPUT_ADD_HOTPLUG_BM_VAR("LED=", dev->ledbit, LED_MAX);
1597         if (test_bit(EV_SND, dev->evbit))
1598                 INPUT_ADD_HOTPLUG_BM_VAR("SND=", dev->sndbit, SND_MAX);
1599         if (test_bit(EV_FF, dev->evbit))
1600                 INPUT_ADD_HOTPLUG_BM_VAR("FF=", dev->ffbit, FF_MAX);
1601         if (test_bit(EV_SW, dev->evbit))
1602                 INPUT_ADD_HOTPLUG_BM_VAR("SW=", dev->swbit, SW_MAX);
1603
1604         INPUT_ADD_HOTPLUG_MODALIAS_VAR(dev);
1605
1606         return 0;
1607 }
1608
1609 #define INPUT_DO_TOGGLE(dev, type, bits, on)                            \
1610         do {                                                            \
1611                 int i;                                                  \
1612                 bool active;                                            \
1613                                                                         \
1614                 if (!test_bit(EV_##type, dev->evbit))                   \
1615                         break;                                          \
1616                                                                         \
1617                 for (i = 0; i < type##_MAX; i++) {                      \
1618                         if (!test_bit(i, dev->bits##bit))               \
1619                                 continue;                               \
1620                                                                         \
1621                         active = test_bit(i, dev->bits);                \
1622                         if (!active && !on)                             \
1623                                 continue;                               \
1624                                                                         \
1625                         dev->event(dev, EV_##type, i, on ? active : 0); \
1626                 }                                                       \
1627         } while (0)
1628
1629 static void input_dev_toggle(struct input_dev *dev, bool activate)
1630 {
1631         if (!dev->event)
1632                 return;
1633
1634         INPUT_DO_TOGGLE(dev, LED, led, activate);
1635         INPUT_DO_TOGGLE(dev, SND, snd, activate);
1636
1637         if (activate && test_bit(EV_REP, dev->evbit)) {
1638                 dev->event(dev, EV_REP, REP_PERIOD, dev->rep[REP_PERIOD]);
1639                 dev->event(dev, EV_REP, REP_DELAY, dev->rep[REP_DELAY]);
1640         }
1641 }
1642
1643 /**
1644  * input_reset_device() - reset/restore the state of input device
1645  * @dev: input device whose state needs to be reset
1646  *
1647  * This function tries to reset the state of an opened input device and
1648  * bring internal state and state if the hardware in sync with each other.
1649  * We mark all keys as released, restore LED state, repeat rate, etc.
1650  */
1651 void input_reset_device(struct input_dev *dev)
1652 {
1653         mutex_lock(&dev->mutex);
1654
1655         if (dev->users) {
1656                 input_dev_toggle(dev, true);
1657
1658                 /*
1659                  * Keys that have been pressed at suspend time are unlikely
1660                  * to be still pressed when we resume.
1661                  */
1662                 spin_lock_irq(&dev->event_lock);
1663                 input_dev_release_keys(dev);
1664                 spin_unlock_irq(&dev->event_lock);
1665         }
1666
1667         mutex_unlock(&dev->mutex);
1668 }
1669 EXPORT_SYMBOL(input_reset_device);
1670
1671 #ifdef CONFIG_PM
1672 static int input_dev_suspend(struct device *dev)
1673 {
1674         struct input_dev *input_dev = to_input_dev(dev);
1675
1676         mutex_lock(&input_dev->mutex);
1677
1678         if (input_dev->users)
1679                 input_dev_toggle(input_dev, false);
1680
1681         mutex_unlock(&input_dev->mutex);
1682
1683         return 0;
1684 }
1685
1686 static int input_dev_resume(struct device *dev)
1687 {
1688         struct input_dev *input_dev = to_input_dev(dev);
1689
1690         input_reset_device(input_dev);
1691
1692         return 0;
1693 }
1694
1695 static const struct dev_pm_ops input_dev_pm_ops = {
1696         .suspend        = input_dev_suspend,
1697         .resume         = input_dev_resume,
1698         .poweroff       = input_dev_suspend,
1699         .restore        = input_dev_resume,
1700 };
1701 #endif /* CONFIG_PM */
1702
1703 static struct device_type input_dev_type = {
1704         .groups         = input_dev_attr_groups,
1705         .release        = input_dev_release,
1706         .uevent         = input_dev_uevent,
1707 #ifdef CONFIG_PM
1708         .pm             = &input_dev_pm_ops,
1709 #endif
1710 };
1711
1712 static char *input_devnode(struct device *dev, umode_t *mode)
1713 {
1714         return kasprintf(GFP_KERNEL, "input/%s", dev_name(dev));
1715 }
1716
1717 struct class input_class = {
1718         .name           = "input",
1719         .devnode        = input_devnode,
1720 };
1721 EXPORT_SYMBOL_GPL(input_class);
1722
1723 /**
1724  * input_allocate_device - allocate memory for new input device
1725  *
1726  * Returns prepared struct input_dev or NULL.
1727  *
1728  * NOTE: Use input_free_device() to free devices that have not been
1729  * registered; input_unregister_device() should be used for already
1730  * registered devices.
1731  */
1732 struct input_dev *input_allocate_device(void)
1733 {
1734         struct input_dev *dev;
1735
1736         dev = kzalloc(sizeof(struct input_dev), GFP_KERNEL);
1737         if (dev) {
1738                 dev->dev.type = &input_dev_type;
1739                 dev->dev.class = &input_class;
1740                 device_initialize(&dev->dev);
1741                 mutex_init(&dev->mutex);
1742                 spin_lock_init(&dev->event_lock);
1743                 INIT_LIST_HEAD(&dev->h_list);
1744                 INIT_LIST_HEAD(&dev->node);
1745
1746                 __module_get(THIS_MODULE);
1747         }
1748
1749         return dev;
1750 }
1751 EXPORT_SYMBOL(input_allocate_device);
1752
1753 /**
1754  * input_free_device - free memory occupied by input_dev structure
1755  * @dev: input device to free
1756  *
1757  * This function should only be used if input_register_device()
1758  * was not called yet or if it failed. Once device was registered
1759  * use input_unregister_device() and memory will be freed once last
1760  * reference to the device is dropped.
1761  *
1762  * Device should be allocated by input_allocate_device().
1763  *
1764  * NOTE: If there are references to the input device then memory
1765  * will not be freed until last reference is dropped.
1766  */
1767 void input_free_device(struct input_dev *dev)
1768 {
1769         if (dev)
1770                 input_put_device(dev);
1771 }
1772 EXPORT_SYMBOL(input_free_device);
1773
1774 /**
1775  * input_set_capability - mark device as capable of a certain event
1776  * @dev: device that is capable of emitting or accepting event
1777  * @type: type of the event (EV_KEY, EV_REL, etc...)
1778  * @code: event code
1779  *
1780  * In addition to setting up corresponding bit in appropriate capability
1781  * bitmap the function also adjusts dev->evbit.
1782  */
1783 void input_set_capability(struct input_dev *dev, unsigned int type, unsigned int code)
1784 {
1785         switch (type) {
1786         case EV_KEY:
1787                 __set_bit(code, dev->keybit);
1788                 break;
1789
1790         case EV_REL:
1791                 __set_bit(code, dev->relbit);
1792                 break;
1793
1794         case EV_ABS:
1795                 __set_bit(code, dev->absbit);
1796                 break;
1797
1798         case EV_MSC:
1799                 __set_bit(code, dev->mscbit);
1800                 break;
1801
1802         case EV_SW:
1803                 __set_bit(code, dev->swbit);
1804                 break;
1805
1806         case EV_LED:
1807                 __set_bit(code, dev->ledbit);
1808                 break;
1809
1810         case EV_SND:
1811                 __set_bit(code, dev->sndbit);
1812                 break;
1813
1814         case EV_FF:
1815                 __set_bit(code, dev->ffbit);
1816                 break;
1817
1818         case EV_PWR:
1819                 /* do nothing */
1820                 break;
1821
1822         default:
1823                 pr_err("input_set_capability: unknown type %u (code %u)\n",
1824                        type, code);
1825                 dump_stack();
1826                 return;
1827         }
1828
1829         __set_bit(type, dev->evbit);
1830 }
1831 EXPORT_SYMBOL(input_set_capability);
1832
1833 static unsigned int input_estimate_events_per_packet(struct input_dev *dev)
1834 {
1835         int mt_slots;
1836         int i;
1837         unsigned int events;
1838
1839         if (dev->mt) {
1840                 mt_slots = dev->mt->num_slots;
1841         } else if (test_bit(ABS_MT_TRACKING_ID, dev->absbit)) {
1842                 mt_slots = dev->absinfo[ABS_MT_TRACKING_ID].maximum -
1843                            dev->absinfo[ABS_MT_TRACKING_ID].minimum + 1,
1844                 mt_slots = clamp(mt_slots, 2, 32);
1845         } else if (test_bit(ABS_MT_POSITION_X, dev->absbit)) {
1846                 mt_slots = 2;
1847         } else {
1848                 mt_slots = 0;
1849         }
1850
1851         events = mt_slots + 1; /* count SYN_MT_REPORT and SYN_REPORT */
1852
1853         for (i = 0; i < ABS_CNT; i++) {
1854                 if (test_bit(i, dev->absbit)) {
1855                         if (input_is_mt_axis(i))
1856                                 events += mt_slots;
1857                         else
1858                                 events++;
1859                 }
1860         }
1861
1862         for (i = 0; i < REL_CNT; i++)
1863                 if (test_bit(i, dev->relbit))
1864                         events++;
1865
1866         /* Make room for KEY and MSC events */
1867         events += 7;
1868
1869         return events;
1870 }
1871
1872 #define INPUT_CLEANSE_BITMASK(dev, type, bits)                          \
1873         do {                                                            \
1874                 if (!test_bit(EV_##type, dev->evbit))                   \
1875                         memset(dev->bits##bit, 0,                       \
1876                                 sizeof(dev->bits##bit));                \
1877         } while (0)
1878
1879 static void input_cleanse_bitmasks(struct input_dev *dev)
1880 {
1881         INPUT_CLEANSE_BITMASK(dev, KEY, key);
1882         INPUT_CLEANSE_BITMASK(dev, REL, rel);
1883         INPUT_CLEANSE_BITMASK(dev, ABS, abs);
1884         INPUT_CLEANSE_BITMASK(dev, MSC, msc);
1885         INPUT_CLEANSE_BITMASK(dev, LED, led);
1886         INPUT_CLEANSE_BITMASK(dev, SND, snd);
1887         INPUT_CLEANSE_BITMASK(dev, FF, ff);
1888         INPUT_CLEANSE_BITMASK(dev, SW, sw);
1889 }
1890
1891 /**
1892  * input_register_device - register device with input core
1893  * @dev: device to be registered
1894  *
1895  * This function registers device with input core. The device must be
1896  * allocated with input_allocate_device() and all it's capabilities
1897  * set up before registering.
1898  * If function fails the device must be freed with input_free_device().
1899  * Once device has been successfully registered it can be unregistered
1900  * with input_unregister_device(); input_free_device() should not be
1901  * called in this case.
1902  */
1903 int input_register_device(struct input_dev *dev)
1904 {
1905         static atomic_t input_no = ATOMIC_INIT(0);
1906         struct input_handler *handler;
1907         unsigned int packet_size;
1908         const char *path;
1909         int error;
1910
1911         /* Every input device generates EV_SYN/SYN_REPORT events. */
1912         __set_bit(EV_SYN, dev->evbit);
1913
1914         /* KEY_RESERVED is not supposed to be transmitted to userspace. */
1915         __clear_bit(KEY_RESERVED, dev->keybit);
1916
1917         /* Make sure that bitmasks not mentioned in dev->evbit are clean. */
1918         input_cleanse_bitmasks(dev);
1919
1920         packet_size = input_estimate_events_per_packet(dev);
1921         if (dev->hint_events_per_packet < packet_size)
1922                 dev->hint_events_per_packet = packet_size;
1923
1924         dev->max_vals = max(dev->hint_events_per_packet, packet_size) + 2;
1925         dev->vals = kcalloc(dev->max_vals, sizeof(*dev->vals), GFP_KERNEL);
1926         if (!dev->vals)
1927                 return -ENOMEM;
1928
1929         /*
1930          * If delay and period are pre-set by the driver, then autorepeating
1931          * is handled by the driver itself and we don't do it in input.c.
1932          */
1933         init_timer(&dev->timer);
1934         if (!dev->rep[REP_DELAY] && !dev->rep[REP_PERIOD]) {
1935                 dev->timer.data = (long) dev;
1936                 dev->timer.function = input_repeat_key;
1937                 dev->rep[REP_DELAY] = 250;
1938                 dev->rep[REP_PERIOD] = 33;
1939         }
1940
1941         if (!dev->getkeycode)
1942                 dev->getkeycode = input_default_getkeycode;
1943
1944         if (!dev->setkeycode)
1945                 dev->setkeycode = input_default_setkeycode;
1946
1947         dev_set_name(&dev->dev, "input%ld",
1948                      (unsigned long) atomic_inc_return(&input_no) - 1);
1949
1950         error = device_add(&dev->dev);
1951         if (error)
1952                 return error;
1953
1954         path = kobject_get_path(&dev->dev.kobj, GFP_KERNEL);
1955         pr_info("%s as %s\n",
1956                 dev->name ? dev->name : "Unspecified device",
1957                 path ? path : "N/A");
1958         kfree(path);
1959
1960         error = mutex_lock_interruptible(&input_mutex);
1961         if (error) {
1962                 device_del(&dev->dev);
1963                 return error;
1964         }
1965
1966         list_add_tail(&dev->node, &input_dev_list);
1967
1968         list_for_each_entry(handler, &input_handler_list, node)
1969                 input_attach_handler(dev, handler);
1970
1971         input_wakeup_procfs_readers();
1972
1973         mutex_unlock(&input_mutex);
1974
1975         return 0;
1976 }
1977 EXPORT_SYMBOL(input_register_device);
1978
1979 /**
1980  * input_unregister_device - unregister previously registered device
1981  * @dev: device to be unregistered
1982  *
1983  * This function unregisters an input device. Once device is unregistered
1984  * the caller should not try to access it as it may get freed at any moment.
1985  */
1986 void input_unregister_device(struct input_dev *dev)
1987 {
1988         struct input_handle *handle, *next;
1989
1990         input_disconnect_device(dev);
1991
1992         mutex_lock(&input_mutex);
1993
1994         list_for_each_entry_safe(handle, next, &dev->h_list, d_node)
1995                 handle->handler->disconnect(handle);
1996         WARN_ON(!list_empty(&dev->h_list));
1997
1998         del_timer_sync(&dev->timer);
1999         list_del_init(&dev->node);
2000
2001         input_wakeup_procfs_readers();
2002
2003         mutex_unlock(&input_mutex);
2004
2005         device_unregister(&dev->dev);
2006 }
2007 EXPORT_SYMBOL(input_unregister_device);
2008
2009 /**
2010  * input_register_handler - register a new input handler
2011  * @handler: handler to be registered
2012  *
2013  * This function registers a new input handler (interface) for input
2014  * devices in the system and attaches it to all input devices that
2015  * are compatible with the handler.
2016  */
2017 int input_register_handler(struct input_handler *handler)
2018 {
2019         struct input_dev *dev;
2020         int error;
2021
2022         error = mutex_lock_interruptible(&input_mutex);
2023         if (error)
2024                 return error;
2025
2026         INIT_LIST_HEAD(&handler->h_list);
2027
2028         list_add_tail(&handler->node, &input_handler_list);
2029
2030         list_for_each_entry(dev, &input_dev_list, node)
2031                 input_attach_handler(dev, handler);
2032
2033         input_wakeup_procfs_readers();
2034
2035         mutex_unlock(&input_mutex);
2036         return 0;
2037 }
2038 EXPORT_SYMBOL(input_register_handler);
2039
2040 /**
2041  * input_unregister_handler - unregisters an input handler
2042  * @handler: handler to be unregistered
2043  *
2044  * This function disconnects a handler from its input devices and
2045  * removes it from lists of known handlers.
2046  */
2047 void input_unregister_handler(struct input_handler *handler)
2048 {
2049         struct input_handle *handle, *next;
2050
2051         mutex_lock(&input_mutex);
2052
2053         list_for_each_entry_safe(handle, next, &handler->h_list, h_node)
2054                 handler->disconnect(handle);
2055         WARN_ON(!list_empty(&handler->h_list));
2056
2057         list_del_init(&handler->node);
2058
2059         input_wakeup_procfs_readers();
2060
2061         mutex_unlock(&input_mutex);
2062 }
2063 EXPORT_SYMBOL(input_unregister_handler);
2064
2065 /**
2066  * input_handler_for_each_handle - handle iterator
2067  * @handler: input handler to iterate
2068  * @data: data for the callback
2069  * @fn: function to be called for each handle
2070  *
2071  * Iterate over @bus's list of devices, and call @fn for each, passing
2072  * it @data and stop when @fn returns a non-zero value. The function is
2073  * using RCU to traverse the list and therefore may be usind in atonic
2074  * contexts. The @fn callback is invoked from RCU critical section and
2075  * thus must not sleep.
2076  */
2077 int input_handler_for_each_handle(struct input_handler *handler, void *data,
2078                                   int (*fn)(struct input_handle *, void *))
2079 {
2080         struct input_handle *handle;
2081         int retval = 0;
2082
2083         rcu_read_lock();
2084
2085         list_for_each_entry_rcu(handle, &handler->h_list, h_node) {
2086                 retval = fn(handle, data);
2087                 if (retval)
2088                         break;
2089         }
2090
2091         rcu_read_unlock();
2092
2093         return retval;
2094 }
2095 EXPORT_SYMBOL(input_handler_for_each_handle);
2096
2097 /**
2098  * input_register_handle - register a new input handle
2099  * @handle: handle to register
2100  *
2101  * This function puts a new input handle onto device's
2102  * and handler's lists so that events can flow through
2103  * it once it is opened using input_open_device().
2104  *
2105  * This function is supposed to be called from handler's
2106  * connect() method.
2107  */
2108 int input_register_handle(struct input_handle *handle)
2109 {
2110         struct input_handler *handler = handle->handler;
2111         struct input_dev *dev = handle->dev;
2112         int error;
2113
2114         /*
2115          * We take dev->mutex here to prevent race with
2116          * input_release_device().
2117          */
2118         error = mutex_lock_interruptible(&dev->mutex);
2119         if (error)
2120                 return error;
2121
2122         /*
2123          * Filters go to the head of the list, normal handlers
2124          * to the tail.
2125          */
2126         if (handler->filter)
2127                 list_add_rcu(&handle->d_node, &dev->h_list);
2128         else
2129                 list_add_tail_rcu(&handle->d_node, &dev->h_list);
2130
2131         mutex_unlock(&dev->mutex);
2132
2133         /*
2134          * Since we are supposed to be called from ->connect()
2135          * which is mutually exclusive with ->disconnect()
2136          * we can't be racing with input_unregister_handle()
2137          * and so separate lock is not needed here.
2138          */
2139         list_add_tail_rcu(&handle->h_node, &handler->h_list);
2140
2141         if (handler->start)
2142                 handler->start(handle);
2143
2144         return 0;
2145 }
2146 EXPORT_SYMBOL(input_register_handle);
2147
2148 /**
2149  * input_unregister_handle - unregister an input handle
2150  * @handle: handle to unregister
2151  *
2152  * This function removes input handle from device's
2153  * and handler's lists.
2154  *
2155  * This function is supposed to be called from handler's
2156  * disconnect() method.
2157  */
2158 void input_unregister_handle(struct input_handle *handle)
2159 {
2160         struct input_dev *dev = handle->dev;
2161
2162         list_del_rcu(&handle->h_node);
2163
2164         /*
2165          * Take dev->mutex to prevent race with input_release_device().
2166          */
2167         mutex_lock(&dev->mutex);
2168         list_del_rcu(&handle->d_node);
2169         mutex_unlock(&dev->mutex);
2170
2171         synchronize_rcu();
2172 }
2173 EXPORT_SYMBOL(input_unregister_handle);
2174
2175 /**
2176  * input_get_new_minor - allocates a new input minor number
2177  * @legacy_base: beginning or the legacy range to be searched
2178  * @legacy_num: size of legacy range
2179  * @allow_dynamic: whether we can also take ID from the dynamic range
2180  *
2181  * This function allocates a new device minor for from input major namespace.
2182  * Caller can request legacy minor by specifying @legacy_base and @legacy_num
2183  * parameters and whether ID can be allocated from dynamic range if there are
2184  * no free IDs in legacy range.
2185  */
2186 int input_get_new_minor(int legacy_base, unsigned int legacy_num,
2187                         bool allow_dynamic)
2188 {
2189         /*
2190          * This function should be called from input handler's ->connect()
2191          * methods, which are serialized with input_mutex, so no additional
2192          * locking is needed here.
2193          */
2194         if (legacy_base >= 0) {
2195                 int minor = ida_simple_get(&input_ida,
2196                                            legacy_base,
2197                                            legacy_base + legacy_num,
2198                                            GFP_KERNEL);
2199                 if (minor >= 0 || !allow_dynamic)
2200                         return minor;
2201         }
2202
2203         return ida_simple_get(&input_ida,
2204                               INPUT_FIRST_DYNAMIC_DEV, INPUT_MAX_CHAR_DEVICES,
2205                               GFP_KERNEL);
2206 }
2207 EXPORT_SYMBOL(input_get_new_minor);
2208
2209 /**
2210  * input_free_minor - release previously allocated minor
2211  * @minor: minor to be released
2212  *
2213  * This function releases previously allocated input minor so that it can be
2214  * reused later.
2215  */
2216 void input_free_minor(unsigned int minor)
2217 {
2218         ida_simple_remove(&input_ida, minor);
2219 }
2220 EXPORT_SYMBOL(input_free_minor);
2221
2222 static int __init input_init(void)
2223 {
2224         int err;
2225
2226         err = class_register(&input_class);
2227         if (err) {
2228                 pr_err("unable to register input_dev class\n");
2229                 return err;
2230         }
2231
2232         err = input_proc_init();
2233         if (err)
2234                 goto fail1;
2235
2236         err = register_chrdev_region(MKDEV(INPUT_MAJOR, 0),
2237                                      INPUT_MAX_CHAR_DEVICES, "input");
2238         if (err) {
2239                 pr_err("unable to register char major %d", INPUT_MAJOR);
2240                 goto fail2;
2241         }
2242
2243         return 0;
2244
2245  fail2: input_proc_exit();
2246  fail1: class_unregister(&input_class);
2247         return err;
2248 }
2249
2250 static void __exit input_exit(void)
2251 {
2252         input_proc_exit();
2253         unregister_chrdev_region(MKDEV(INPUT_MAJOR, 0),
2254                                  INPUT_MAX_CHAR_DEVICES);
2255         class_unregister(&input_class);
2256 }
2257
2258 subsys_initcall(input_init);
2259 module_exit(input_exit);