linux/drivers/input/input.c
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   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
  32MODULE_AUTHOR("Vojtech Pavlik <vojtech@suse.cz>");
  33MODULE_DESCRIPTION("Input core");
  34MODULE_LICENSE("GPL");
  35
  36#define INPUT_MAX_CHAR_DEVICES          1024
  37#define INPUT_FIRST_DYNAMIC_DEV         256
  38static DEFINE_IDA(input_ida);
  39
  40static LIST_HEAD(input_dev_list);
  41static 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 */
  49static DEFINE_MUTEX(input_mutex);
  50
  51static const struct input_value input_value_sync = { EV_SYN, SYN_REPORT, 1 };
  52
  53static 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
  59static 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
  75static 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
  86static 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 */
  96static 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 */
 130static 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
 165static 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 */
 178static 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
 209static 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
 259static 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
 363static 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 */
 421void 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}
 433EXPORT_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 */
 446void 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}
 465EXPORT_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 */
 474void 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}
 482EXPORT_SYMBOL(input_alloc_absinfo);
 483
 484void 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}
 501EXPORT_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 */
 512int 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}
 532EXPORT_SYMBOL(input_grab_device);
 533
 534static 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 */
 558void 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}
 566EXPORT_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 */
 575int 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}
 609EXPORT_SYMBOL(input_open_device);
 610
 611int 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}
 626EXPORT_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 */
 635void 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}
 657EXPORT_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 */
 663static 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 */
 681static 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 */
 720int 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}
 742EXPORT_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
 749static 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
 764static 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
 792static 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 */
 860int 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}
 871EXPORT_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 */
 881int 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}
 920EXPORT_SYMBOL(input_set_keycode);
 921
 922static 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
 979static 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
 998static 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
1022static 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
1033static struct proc_dir_entry *proc_bus_input_dir;
1034static DECLARE_WAIT_QUEUE_HEAD(input_devices_poll_wait);
1035static int input_devices_state;
1036
1037static inline void input_wakeup_procfs_readers(void)
1038{
1039        input_devices_state++;
1040        wake_up(&input_devices_poll_wait);
1041}
1042
1043static 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
1054union input_seq_state {
1055        struct {
1056                unsigned short pos;
1057                bool mutex_acquired;
1058        };
1059        void *p;
1060};
1061
1062static 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
1081static 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
1086static 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
1094static 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
1120static 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
1165static 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
1172static int input_proc_devices_open(struct inode *inode, struct file *file)
1173{
1174        return seq_open(file, &input_devices_seq_ops);
1175}
1176
1177static 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
1186static 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
1206static 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
1214static 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
1229static 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
1236static int input_proc_handlers_open(struct inode *inode, struct file *file)
1237{
1238        return seq_open(file, &input_handlers_seq_ops);
1239}
1240
1241static 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
1249static 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
1274static 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 */
1282static inline void input_wakeup_procfs_readers(void) { }
1283static inline int input_proc_init(void) { return 0; }
1284static inline void input_proc_exit(void) { }
1285#endif
1286
1287#define INPUT_DEV_STRING_ATTR_SHOW(name)                                \
1288static 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}                                                                       \
1297static DEVICE_ATTR(name, S_IRUGO, input_dev_show_##name, NULL)
1298
1299INPUT_DEV_STRING_ATTR_SHOW(name);
1300INPUT_DEV_STRING_ATTR_SHOW(phys);
1301INPUT_DEV_STRING_ATTR_SHOW(uniq);
1302
1303static 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
1316static 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
1351static 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}
1362static DEVICE_ATTR(modalias, S_IRUGO, input_dev_show_modalias, NULL);
1363
1364static int input_print_bitmap(char *buf, int buf_size, unsigned long *bitmap,
1365                              int max, int add_cr);
1366
1367static 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}
1376static DEVICE_ATTR(properties, S_IRUGO, input_dev_show_properties, NULL);
1377
1378static 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
1387static struct attribute_group input_dev_attr_group = {
1388        .attrs  = input_dev_attrs,
1389};
1390
1391#define INPUT_DEV_ID_ATTR(name)                                         \
1392static 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}                                                                       \
1399static DEVICE_ATTR(name, S_IRUGO, input_dev_show_id_##name, NULL)
1400
1401INPUT_DEV_ID_ATTR(bustype);
1402INPUT_DEV_ID_ATTR(vendor);
1403INPUT_DEV_ID_ATTR(product);
1404INPUT_DEV_ID_ATTR(version);
1405
1406static 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
1414static struct attribute_group input_dev_id_attr_group = {
1415        .name   = "id",
1416        .attrs  = input_dev_id_attrs,
1417};
1418
1419static 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)                                      \
1449static 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}                                                                       \
1459static DEVICE_ATTR(bm, S_IRUGO, input_dev_show_cap_##bm, NULL)
1460
1461INPUT_DEV_CAP_ATTR(EV, ev);
1462INPUT_DEV_CAP_ATTR(KEY, key);
1463INPUT_DEV_CAP_ATTR(REL, rel);
1464INPUT_DEV_CAP_ATTR(ABS, abs);
1465INPUT_DEV_CAP_ATTR(MSC, msc);
1466INPUT_DEV_CAP_ATTR(LED, led);
1467INPUT_DEV_CAP_ATTR(SND, snd);
1468INPUT_DEV_CAP_ATTR(FF, ff);
1469INPUT_DEV_CAP_ATTR(SW, sw);
1470
1471static 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
1484static struct attribute_group input_dev_caps_attr_group = {
1485        .name   = "capabilities",
1486        .attrs  = input_dev_caps_attrs,
1487};
1488
1489static 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
1496static 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 */
1513static 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
1531static 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
1570static 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
1629static 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 */
1651void 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}
1669EXPORT_SYMBOL(input_reset_device);
1670
1671#ifdef CONFIG_PM
1672static 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
1686static 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
1695static 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
1703static 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
1712static char *input_devnode(struct device *dev, umode_t *mode)
1713{
1714        return kasprintf(GFP_KERNEL, "input/%s", dev_name(dev));
1715}
1716
1717struct class input_class = {
1718        .name           = "input",
1719        .devnode        = input_devnode,
1720};
1721EXPORT_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 */
1732struct 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}
1751EXPORT_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 */
1767void input_free_device(struct input_dev *dev)
1768{
1769        if (dev)
1770                input_put_device(dev);
1771}
1772EXPORT_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 */
1783void 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}
1831EXPORT_SYMBOL(input_set_capability);
1832
1833static 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
1879static 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 */
1903int 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}
1977EXPORT_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 */
1986void 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}
2007EXPORT_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 */
2017int 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}
2038EXPORT_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 */
2047void 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}
2063EXPORT_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 */
2077int 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}
2095EXPORT_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 */
2108int 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}
2146EXPORT_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 */
2158void 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}
2173EXPORT_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 */
2186int 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}
2207EXPORT_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 */
2216void input_free_minor(unsigned int minor)
2217{
2218        ida_simple_remove(&input_ida, minor);
2219}
2220EXPORT_SYMBOL(input_free_minor);
2221
2222static 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
2250static 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
2258subsys_initcall(input_init);
2259module_exit(input_exit);
2260
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