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