drivers/input/input.c

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This source file includes following definitions.
is_event_supported
input_defuzz_abs_event
input_start_autorepeat
input_stop_autorepeat
input_to_handler
input_pass_values
input_pass_event
input_repeat_key
input_handle_abs_event
input_get_disposition
input_handle_event
input_event
input_inject_event
input_alloc_absinfo
input_set_abs_params
input_grab_device
__input_release_device
input_release_device
input_open_device
input_flush_device
input_close_device
input_dev_release_keys
input_disconnect_device
input_scancode_to_scalar
input_fetch_keycode
input_default_getkeycode
input_default_setkeycode
input_get_keycode
input_set_keycode
input_match_device_id
input_match_device
input_attach_handler
input_bits_to_string
input_bits_to_string
input_wakeup_procfs_readers
input_proc_devices_poll
input_devices_seq_start
input_devices_seq_next
input_seq_stop
input_seq_print_bitmap
input_devices_seq_show
input_proc_devices_open
input_handlers_seq_start
input_handlers_seq_next
input_handlers_seq_show
input_proc_handlers_open
input_proc_init
input_proc_exit
input_wakeup_procfs_readers
input_proc_init
input_proc_exit
input_print_modalias_bits
input_print_modalias
input_dev_show_modalias
input_dev_show_properties
input_print_bitmap
input_dev_release
input_add_uevent_bm_var
input_add_uevent_modalias_var
input_dev_uevent
input_dev_toggle
input_reset_device
input_dev_suspend
input_dev_resume
input_dev_freeze
input_dev_poweroff
input_devnode
input_allocate_device
devm_input_device_match
devm_input_device_release
devm_input_allocate_device
input_free_device
input_set_timestamp
input_get_timestamp
input_set_capability
input_estimate_events_per_packet
input_cleanse_bitmasks
__input_unregister_device
devm_input_device_unregister
input_enable_softrepeat
input_register_device
input_unregister_device
input_register_handler
input_unregister_handler
input_handler_for_each_handle
input_register_handle
input_unregister_handle
input_get_new_minor
input_free_minor
input_init
input_exit
   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * The input core
   4  *
   5  * Copyright (c) 1999-2002 Vojtech Pavlik
   6  */
   7 
   8 
   9 #define pr_fmt(fmt) KBUILD_BASENAME ": " fmt
  10 
  11 #include <linux/init.h>
  12 #include <linux/types.h>
  13 #include <linux/idr.h>
  14 #include <linux/input/mt.h>
  15 #include <linux/module.h>
  16 #include <linux/slab.h>
  17 #include <linux/random.h>
  18 #include <linux/major.h>
  19 #include <linux/proc_fs.h>
  20 #include <linux/sched.h>
  21 #include <linux/seq_file.h>
  22 #include <linux/poll.h>
  23 #include <linux/device.h>
  24 #include <linux/mutex.h>
  25 #include <linux/rcupdate.h>
  26 #include "input-compat.h"
  27 #include "input-poller.h"
  28 
  29 MODULE_AUTHOR("Vojtech Pavlik <vojtech@suse.cz>");
  30 MODULE_DESCRIPTION("Input core");
  31 MODULE_LICENSE("GPL");
  32 
  33 #define INPUT_MAX_CHAR_DEVICES          1024
  34 #define INPUT_FIRST_DYNAMIC_DEV         256
  35 static DEFINE_IDA(input_ida);
  36 
  37 static LIST_HEAD(input_dev_list);
  38 static LIST_HEAD(input_handler_list);
  39 
  40 /*
  41  * input_mutex protects access to both input_dev_list and input_handler_list.
  42  * This also causes input_[un]register_device and input_[un]register_handler
  43  * be mutually exclusive which simplifies locking in drivers implementing
  44  * input handlers.
  45  */
  46 static DEFINE_MUTEX(input_mutex);
  47 
  48 static const struct input_value input_value_sync = { EV_SYN, SYN_REPORT, 1 };
  49 
  50 static inline int is_event_supported(unsigned int code,
  51                                      unsigned long *bm, unsigned int max)
  52 {
  53         return code <= max && test_bit(code, bm);
  54 }
  55 
  56 static int input_defuzz_abs_event(int value, int old_val, int fuzz)
  57 {
  58         if (fuzz) {
  59                 if (value > old_val - fuzz / 2 && value < old_val + fuzz / 2)
  60                         return old_val;
  61 
  62                 if (value > old_val - fuzz && value < old_val + fuzz)
  63                         return (old_val * 3 + value) / 4;
  64 
  65                 if (value > old_val - fuzz * 2 && value < old_val + fuzz * 2)
  66                         return (old_val + value) / 2;
  67         }
  68 
  69         return value;
  70 }
  71 
  72 static void input_start_autorepeat(struct input_dev *dev, int code)
  73 {
  74         if (test_bit(EV_REP, dev->evbit) &&
  75             dev->rep[REP_PERIOD] && dev->rep[REP_DELAY] &&
  76             dev->timer.function) {
  77                 dev->repeat_key = code;
  78                 mod_timer(&dev->timer,
  79                           jiffies + msecs_to_jiffies(dev->rep[REP_DELAY]));
  80         }
  81 }
  82 
  83 static void input_stop_autorepeat(struct input_dev *dev)
  84 {
  85         del_timer(&dev->timer);
  86 }
  87 
  88 /*
  89  * Pass event first through all filters and then, if event has not been
  90  * filtered out, through all open handles. This function is called with
  91  * dev->event_lock held and interrupts disabled.
  92  */
  93 static unsigned int input_to_handler(struct input_handle *handle,
  94                         struct input_value *vals, unsigned int count)
  95 {
  96         struct input_handler *handler = handle->handler;
  97         struct input_value *end = vals;
  98         struct input_value *v;
  99 
 100         if (handler->filter) {
 101                 for (v = vals; v != vals + count; v++) {
 102                         if (handler->filter(handle, v->type, v->code, v->value))
 103                                 continue;
 104                         if (end != v)
 105                                 *end = *v;
 106                         end++;
 107                 }
 108                 count = end - vals;
 109         }
 110 
 111         if (!count)
 112                 return 0;
 113 
 114         if (handler->events)
 115                 handler->events(handle, vals, count);
 116         else if (handler->event)
 117                 for (v = vals; v != vals + count; v++)
 118                         handler->event(handle, v->type, v->code, v->value);
 119 
 120         return count;
 121 }
 122 
 123 /*
 124  * Pass values first through all filters and then, if event has not been
 125  * filtered out, through all open handles. This function is called with
 126  * dev->event_lock held and interrupts disabled.
 127  */
 128 static void input_pass_values(struct input_dev *dev,
 129                               struct input_value *vals, unsigned int count)
 130 {
 131         struct input_handle *handle;
 132         struct input_value *v;
 133 
 134         if (!count)
 135                 return;
 136 
 137         rcu_read_lock();
 138 
 139         handle = rcu_dereference(dev->grab);
 140         if (handle) {
 141                 count = input_to_handler(handle, vals, count);
 142         } else {
 143                 list_for_each_entry_rcu(handle, &dev->h_list, d_node)
 144                         if (handle->open) {
 145                                 count = input_to_handler(handle, vals, count);
 146                                 if (!count)
 147                                         break;
 148                         }
 149         }
 150 
 151         rcu_read_unlock();
 152 
 153         /* trigger auto repeat for key events */
 154         if (test_bit(EV_REP, dev->evbit) && test_bit(EV_KEY, dev->evbit)) {
 155                 for (v = vals; v != vals + count; v++) {
 156                         if (v->type == EV_KEY && v->value != 2) {
 157                                 if (v->value)
 158                                         input_start_autorepeat(dev, v->code);
 159                                 else
 160                                         input_stop_autorepeat(dev);
 161                         }
 162                 }
 163         }
 164 }
 165 
 166 static void input_pass_event(struct input_dev *dev,
 167                              unsigned int type, unsigned int code, int value)
 168 {
 169         struct input_value vals[] = { { type, code, value } };
 170 
 171         input_pass_values(dev, vals, ARRAY_SIZE(vals));
 172 }
 173 
 174 /*
 175  * Generate software autorepeat event. Note that we take
 176  * dev->event_lock here to avoid racing with input_event
 177  * which may cause keys get "stuck".
 178  */
 179 static void input_repeat_key(struct timer_list *t)
 180 {
 181         struct input_dev *dev = from_timer(dev, t, timer);
 182         unsigned long flags;
 183 
 184         spin_lock_irqsave(&dev->event_lock, flags);
 185 
 186         if (test_bit(dev->repeat_key, dev->key) &&
 187             is_event_supported(dev->repeat_key, dev->keybit, KEY_MAX)) {
 188                 struct input_value vals[] =  {
 189                         { EV_KEY, dev->repeat_key, 2 },
 190                         input_value_sync
 191                 };
 192 
 193                 input_set_timestamp(dev, ktime_get());
 194                 input_pass_values(dev, vals, ARRAY_SIZE(vals));
 195 
 196                 if (dev->rep[REP_PERIOD])
 197                         mod_timer(&dev->timer, jiffies +
 198                                         msecs_to_jiffies(dev->rep[REP_PERIOD]));
 199         }
 200 
 201         spin_unlock_irqrestore(&dev->event_lock, flags);
 202 }
 203 
 204 #define INPUT_IGNORE_EVENT      0
 205 #define INPUT_PASS_TO_HANDLERS  1
 206 #define INPUT_PASS_TO_DEVICE    2
 207 #define INPUT_SLOT              4
 208 #define INPUT_FLUSH             8
 209 #define INPUT_PASS_TO_ALL       (INPUT_PASS_TO_HANDLERS | INPUT_PASS_TO_DEVICE)
 210 
 211 static int input_handle_abs_event(struct input_dev *dev,
 212                                   unsigned int code, int *pval)
 213 {
 214         struct input_mt *mt = dev->mt;
 215         bool is_mt_event;
 216         int *pold;
 217 
 218         if (code == ABS_MT_SLOT) {
 219                 /*
 220                  * "Stage" the event; we'll flush it later, when we
 221                  * get actual touch data.
 222                  */
 223                 if (mt && *pval >= 0 && *pval < mt->num_slots)
 224                         mt->slot = *pval;
 225 
 226                 return INPUT_IGNORE_EVENT;
 227         }
 228 
 229         is_mt_event = input_is_mt_value(code);
 230 
 231         if (!is_mt_event) {
 232                 pold = &dev->absinfo[code].value;
 233         } else if (mt) {
 234                 pold = &mt->slots[mt->slot].abs[code - ABS_MT_FIRST];
 235         } else {
 236                 /*
 237                  * Bypass filtering for multi-touch events when
 238                  * not employing slots.
 239                  */
 240                 pold = NULL;
 241         }
 242 
 243         if (pold) {
 244                 *pval = input_defuzz_abs_event(*pval, *pold,
 245                                                 dev->absinfo[code].fuzz);
 246                 if (*pold == *pval)
 247                         return INPUT_IGNORE_EVENT;
 248 
 249                 *pold = *pval;
 250         }
 251 
 252         /* Flush pending "slot" event */
 253         if (is_mt_event && mt && mt->slot != input_abs_get_val(dev, ABS_MT_SLOT)) {
 254                 input_abs_set_val(dev, ABS_MT_SLOT, mt->slot);
 255                 return INPUT_PASS_TO_HANDLERS | INPUT_SLOT;
 256         }
 257 
 258         return INPUT_PASS_TO_HANDLERS;
 259 }
 260 
 261 static int input_get_disposition(struct input_dev *dev,
 262                           unsigned int type, unsigned int code, int *pval)
 263 {
 264         int disposition = INPUT_IGNORE_EVENT;
 265         int value = *pval;
 266 
 267         switch (type) {
 268 
 269         case EV_SYN:
 270                 switch (code) {
 271                 case SYN_CONFIG:
 272                         disposition = INPUT_PASS_TO_ALL;
 273                         break;
 274 
 275                 case SYN_REPORT:
 276                         disposition = INPUT_PASS_TO_HANDLERS | INPUT_FLUSH;
 277                         break;
 278                 case SYN_MT_REPORT:
 279                         disposition = INPUT_PASS_TO_HANDLERS;
 280                         break;
 281                 }
 282                 break;
 283 
 284         case EV_KEY:
 285                 if (is_event_supported(code, dev->keybit, KEY_MAX)) {
 286 
 287                         /* auto-repeat bypasses state updates */
 288                         if (value == 2) {
 289                                 disposition = INPUT_PASS_TO_HANDLERS;
 290                                 break;
 291                         }
 292 
 293                         if (!!test_bit(code, dev->key) != !!value) {
 294 
 295                                 __change_bit(code, dev->key);
 296                                 disposition = INPUT_PASS_TO_HANDLERS;
 297                         }
 298                 }
 299                 break;
 300 
 301         case EV_SW:
 302                 if (is_event_supported(code, dev->swbit, SW_MAX) &&
 303                     !!test_bit(code, dev->sw) != !!value) {
 304 
 305                         __change_bit(code, dev->sw);
 306                         disposition = INPUT_PASS_TO_HANDLERS;
 307                 }
 308                 break;
 309 
 310         case EV_ABS:
 311                 if (is_event_supported(code, dev->absbit, ABS_MAX))
 312                         disposition = input_handle_abs_event(dev, code, &value);
 313 
 314                 break;
 315 
 316         case EV_REL:
 317                 if (is_event_supported(code, dev->relbit, REL_MAX) && value)
 318                         disposition = INPUT_PASS_TO_HANDLERS;
 319 
 320                 break;
 321 
 322         case EV_MSC:
 323                 if (is_event_supported(code, dev->mscbit, MSC_MAX))
 324                         disposition = INPUT_PASS_TO_ALL;
 325 
 326                 break;
 327 
 328         case EV_LED:
 329                 if (is_event_supported(code, dev->ledbit, LED_MAX) &&
 330                     !!test_bit(code, dev->led) != !!value) {
 331 
 332                         __change_bit(code, dev->led);
 333                         disposition = INPUT_PASS_TO_ALL;
 334                 }
 335                 break;
 336 
 337         case EV_SND:
 338                 if (is_event_supported(code, dev->sndbit, SND_MAX)) {
 339 
 340                         if (!!test_bit(code, dev->snd) != !!value)
 341                                 __change_bit(code, dev->snd);
 342                         disposition = INPUT_PASS_TO_ALL;
 343                 }
 344                 break;
 345 
 346         case EV_REP:
 347                 if (code <= REP_MAX && value >= 0 && dev->rep[code] != value) {
 348                         dev->rep[code] = value;
 349                         disposition = INPUT_PASS_TO_ALL;
 350                 }
 351                 break;
 352 
 353         case EV_FF:
 354                 if (value >= 0)
 355                         disposition = INPUT_PASS_TO_ALL;
 356                 break;
 357 
 358         case EV_PWR:
 359                 disposition = INPUT_PASS_TO_ALL;
 360                 break;
 361         }
 362 
 363         *pval = value;
 364         return disposition;
 365 }
 366 
 367 static void input_handle_event(struct input_dev *dev,
 368                                unsigned int type, unsigned int code, int value)
 369 {
 370         int disposition = input_get_disposition(dev, type, code, &value);
 371 
 372         if (disposition != INPUT_IGNORE_EVENT && type != EV_SYN)
 373                 add_input_randomness(type, code, value);
 374 
 375         if ((disposition & INPUT_PASS_TO_DEVICE) && dev->event)
 376                 dev->event(dev, type, code, value);
 377 
 378         if (!dev->vals)
 379                 return;
 380 
 381         if (disposition & INPUT_PASS_TO_HANDLERS) {
 382                 struct input_value *v;
 383 
 384                 if (disposition & INPUT_SLOT) {
 385                         v = &dev->vals[dev->num_vals++];
 386                         v->type = EV_ABS;
 387                         v->code = ABS_MT_SLOT;
 388                         v->value = dev->mt->slot;
 389                 }
 390 
 391                 v = &dev->vals[dev->num_vals++];
 392                 v->type = type;
 393                 v->code = code;
 394                 v->value = value;
 395         }
 396 
 397         if (disposition & INPUT_FLUSH) {
 398                 if (dev->num_vals >= 2)
 399                         input_pass_values(dev, dev->vals, dev->num_vals);
 400                 dev->num_vals = 0;
 401                 /*
 402                  * Reset the timestamp on flush so we won't end up
 403                  * with a stale one. Note we only need to reset the
 404                  * monolithic one as we use its presence when deciding
 405                  * whether to generate a synthetic timestamp.
 406                  */
 407                 dev->timestamp[INPUT_CLK_MONO] = ktime_set(0, 0);
 408         } else if (dev->num_vals >= dev->max_vals - 2) {
 409                 dev->vals[dev->num_vals++] = input_value_sync;
 410                 input_pass_values(dev, dev->vals, dev->num_vals);
 411                 dev->num_vals = 0;
 412         }
 413 
 414 }
 415 
 416 /**
 417  * input_event() - report new input event
 418  * @dev: device that generated the event
 419  * @type: type of the event
 420  * @code: event code
 421  * @value: value of the event
 422  *
 423  * This function should be used by drivers implementing various input
 424  * devices to report input events. See also input_inject_event().
 425  *
 426  * NOTE: input_event() may be safely used right after input device was
 427  * allocated with input_allocate_device(), even before it is registered
 428  * with input_register_device(), but the event will not reach any of the
 429  * input handlers. Such early invocation of input_event() may be used
 430  * to 'seed' initial state of a switch or initial position of absolute
 431  * axis, etc.
 432  */
 433 void input_event(struct input_dev *dev,
 434                  unsigned int type, unsigned int code, int value)
 435 {
 436         unsigned long flags;
 437 
 438         if (is_event_supported(type, dev->evbit, EV_MAX)) {
 439 
 440                 spin_lock_irqsave(&dev->event_lock, flags);
 441                 input_handle_event(dev, type, code, value);
 442                 spin_unlock_irqrestore(&dev->event_lock, flags);
 443         }
 444 }
 445 EXPORT_SYMBOL(input_event);
 446 
 447 /**
 448  * input_inject_event() - send input event from input handler
 449  * @handle: input handle to send event through
 450  * @type: type of the event
 451  * @code: event code
 452  * @value: value of the event
 453  *
 454  * Similar to input_event() but will ignore event if device is
 455  * "grabbed" and handle injecting event is not the one that owns
 456  * the device.
 457  */
 458 void input_inject_event(struct input_handle *handle,
 459                         unsigned int type, unsigned int code, int value)
 460 {
 461         struct input_dev *dev = handle->dev;
 462         struct input_handle *grab;
 463         unsigned long flags;
 464 
 465         if (is_event_supported(type, dev->evbit, EV_MAX)) {
 466                 spin_lock_irqsave(&dev->event_lock, flags);
 467 
 468                 rcu_read_lock();
 469                 grab = rcu_dereference(dev->grab);
 470                 if (!grab || grab == handle)
 471                         input_handle_event(dev, type, code, value);
 472                 rcu_read_unlock();
 473 
 474                 spin_unlock_irqrestore(&dev->event_lock, flags);
 475         }
 476 }
 477 EXPORT_SYMBOL(input_inject_event);
 478 
 479 /**
 480  * input_alloc_absinfo - allocates array of input_absinfo structs
 481  * @dev: the input device emitting absolute events
 482  *
 483  * If the absinfo struct the caller asked for is already allocated, this
 484  * functions will not do anything.
 485  */
 486 void input_alloc_absinfo(struct input_dev *dev)
 487 {
 488         if (dev->absinfo)
 489                 return;
 490 
 491         dev->absinfo = kcalloc(ABS_CNT, sizeof(*dev->absinfo), GFP_KERNEL);
 492         if (!dev->absinfo) {
 493                 dev_err(dev->dev.parent ?: &dev->dev,
 494                         "%s: unable to allocate memory\n", __func__);
 495                 /*
 496                  * We will handle this allocation failure in
 497                  * input_register_device() when we refuse to register input
 498                  * device with ABS bits but without absinfo.
 499                  */
 500         }
 501 }
 502 EXPORT_SYMBOL(input_alloc_absinfo);
 503 
 504 void input_set_abs_params(struct input_dev *dev, unsigned int axis,
 505                           int min, int max, int fuzz, int flat)
 506 {
 507         struct input_absinfo *absinfo;
 508 
 509         input_alloc_absinfo(dev);
 510         if (!dev->absinfo)
 511                 return;
 512 
 513         absinfo = &dev->absinfo[axis];
 514         absinfo->minimum = min;
 515         absinfo->maximum = max;
 516         absinfo->fuzz = fuzz;
 517         absinfo->flat = flat;
 518 
 519         __set_bit(EV_ABS, dev->evbit);
 520         __set_bit(axis, dev->absbit);
 521 }
 522 EXPORT_SYMBOL(input_set_abs_params);
 523 
 524 
 525 /**
 526  * input_grab_device - grabs device for exclusive use
 527  * @handle: input handle that wants to own the device
 528  *
 529  * When a device is grabbed by an input handle all events generated by
 530  * the device are delivered only to this handle. Also events injected
 531  * by other input handles are ignored while device is grabbed.
 532  */
 533 int input_grab_device(struct input_handle *handle)
 534 {
 535         struct input_dev *dev = handle->dev;
 536         int retval;
 537 
 538         retval = mutex_lock_interruptible(&dev->mutex);
 539         if (retval)
 540                 return retval;
 541 
 542         if (dev->grab) {
 543                 retval = -EBUSY;
 544                 goto out;
 545         }
 546 
 547         rcu_assign_pointer(dev->grab, handle);
 548 
 549  out:
 550         mutex_unlock(&dev->mutex);
 551         return retval;
 552 }
 553 EXPORT_SYMBOL(input_grab_device);
 554 
 555 static void __input_release_device(struct input_handle *handle)
 556 {
 557         struct input_dev *dev = handle->dev;
 558         struct input_handle *grabber;
 559 
 560         grabber = rcu_dereference_protected(dev->grab,
 561                                             lockdep_is_held(&dev->mutex));
 562         if (grabber == handle) {
 563                 rcu_assign_pointer(dev->grab, NULL);
 564                 /* Make sure input_pass_event() notices that grab is gone */
 565                 synchronize_rcu();
 566 
 567                 list_for_each_entry(handle, &dev->h_list, d_node)
 568                         if (handle->open && handle->handler->start)
 569                                 handle->handler->start(handle);
 570         }
 571 }
 572 
 573 /**
 574  * input_release_device - release previously grabbed device
 575  * @handle: input handle that owns the device
 576  *
 577  * Releases previously grabbed device so that other input handles can
 578  * start receiving input events. Upon release all handlers attached
 579  * to the device have their start() method called so they have a change
 580  * to synchronize device state with the rest of the system.
 581  */
 582 void input_release_device(struct input_handle *handle)
 583 {
 584         struct input_dev *dev = handle->dev;
 585 
 586         mutex_lock(&dev->mutex);
 587         __input_release_device(handle);
 588         mutex_unlock(&dev->mutex);
 589 }
 590 EXPORT_SYMBOL(input_release_device);
 591 
 592 /**
 593  * input_open_device - open input device
 594  * @handle: handle through which device is being accessed
 595  *
 596  * This function should be called by input handlers when they
 597  * want to start receive events from given input device.
 598  */
 599 int input_open_device(struct input_handle *handle)
 600 {
 601         struct input_dev *dev = handle->dev;
 602         int retval;
 603 
 604         retval = mutex_lock_interruptible(&dev->mutex);
 605         if (retval)
 606                 return retval;
 607 
 608         if (dev->going_away) {
 609                 retval = -ENODEV;
 610                 goto out;
 611         }
 612 
 613         handle->open++;
 614 
 615         if (dev->users++) {
 616                 /*
 617                  * Device is already opened, so we can exit immediately and
 618                  * report success.
 619                  */
 620                 goto out;
 621         }
 622 
 623         if (dev->open) {
 624                 retval = dev->open(dev);
 625                 if (retval) {
 626                         dev->users--;
 627                         handle->open--;
 628                         /*
 629                          * Make sure we are not delivering any more events
 630                          * through this handle
 631                          */
 632                         synchronize_rcu();
 633                         goto out;
 634                 }
 635         }
 636 
 637         if (dev->poller)
 638                 input_dev_poller_start(dev->poller);
 639 
 640  out:
 641         mutex_unlock(&dev->mutex);
 642         return retval;
 643 }
 644 EXPORT_SYMBOL(input_open_device);
 645 
 646 int input_flush_device(struct input_handle *handle, struct file *file)
 647 {
 648         struct input_dev *dev = handle->dev;
 649         int retval;
 650 
 651         retval = mutex_lock_interruptible(&dev->mutex);
 652         if (retval)
 653                 return retval;
 654 
 655         if (dev->flush)
 656                 retval = dev->flush(dev, file);
 657 
 658         mutex_unlock(&dev->mutex);
 659         return retval;
 660 }
 661 EXPORT_SYMBOL(input_flush_device);
 662 
 663 /**
 664  * input_close_device - close input device
 665  * @handle: handle through which device is being accessed
 666  *
 667  * This function should be called by input handlers when they
 668  * want to stop receive events from given input device.
 669  */
 670 void input_close_device(struct input_handle *handle)
 671 {
 672         struct input_dev *dev = handle->dev;
 673 
 674         mutex_lock(&dev->mutex);
 675 
 676         __input_release_device(handle);
 677 
 678         if (!--dev->users) {
 679                 if (dev->poller)
 680                         input_dev_poller_stop(dev->poller);
 681 
 682                 if (dev->close)
 683                         dev->close(dev);
 684         }
 685 
 686         if (!--handle->open) {
 687                 /*
 688                  * synchronize_rcu() makes sure that input_pass_event()
 689                  * completed and that no more input events are delivered
 690                  * through this handle
 691                  */
 692                 synchronize_rcu();
 693         }
 694 
 695         mutex_unlock(&dev->mutex);
 696 }
 697 EXPORT_SYMBOL(input_close_device);
 698 
 699 /*
 700  * Simulate keyup events for all keys that are marked as pressed.
 701  * The function must be called with dev->event_lock held.
 702  */
 703 static void input_dev_release_keys(struct input_dev *dev)
 704 {
 705         bool need_sync = false;
 706         int code;
 707 
 708         if (is_event_supported(EV_KEY, dev->evbit, EV_MAX)) {
 709                 for_each_set_bit(code, dev->key, KEY_CNT) {
 710                         input_pass_event(dev, EV_KEY, code, 0);
 711                         need_sync = true;
 712                 }
 713 
 714                 if (need_sync)
 715                         input_pass_event(dev, EV_SYN, SYN_REPORT, 1);
 716 
 717                 memset(dev->key, 0, sizeof(dev->key));
 718         }
 719 }
 720 
 721 /*
 722  * Prepare device for unregistering
 723  */
 724 static void input_disconnect_device(struct input_dev *dev)
 725 {
 726         struct input_handle *handle;
 727 
 728         /*
 729          * Mark device as going away. Note that we take dev->mutex here
 730          * not to protect access to dev->going_away but rather to ensure
 731          * that there are no threads in the middle of input_open_device()
 732          */
 733         mutex_lock(&dev->mutex);
 734         dev->going_away = true;
 735         mutex_unlock(&dev->mutex);
 736 
 737         spin_lock_irq(&dev->event_lock);
 738 
 739         /*
 740          * Simulate keyup events for all pressed keys so that handlers
 741          * are not left with "stuck" keys. The driver may continue
 742          * generate events even after we done here but they will not
 743          * reach any handlers.
 744          */
 745         input_dev_release_keys(dev);
 746 
 747         list_for_each_entry(handle, &dev->h_list, d_node)
 748                 handle->open = 0;
 749 
 750         spin_unlock_irq(&dev->event_lock);
 751 }
 752 
 753 /**
 754  * input_scancode_to_scalar() - converts scancode in &struct input_keymap_entry
 755  * @ke: keymap entry containing scancode to be converted.
 756  * @scancode: pointer to the location where converted scancode should
 757  *      be stored.
 758  *
 759  * This function is used to convert scancode stored in &struct keymap_entry
 760  * into scalar form understood by legacy keymap handling methods. These
 761  * methods expect scancodes to be represented as 'unsigned int'.
 762  */
 763 int input_scancode_to_scalar(const struct input_keymap_entry *ke,
 764                              unsigned int *scancode)
 765 {
 766         switch (ke->len) {
 767         case 1:
 768                 *scancode = *((u8 *)ke->scancode);
 769                 break;
 770 
 771         case 2:
 772                 *scancode = *((u16 *)ke->scancode);
 773                 break;
 774 
 775         case 4:
 776                 *scancode = *((u32 *)ke->scancode);
 777                 break;
 778 
 779         default:
 780                 return -EINVAL;
 781         }
 782 
 783         return 0;
 784 }
 785 EXPORT_SYMBOL(input_scancode_to_scalar);
 786 
 787 /*
 788  * Those routines handle the default case where no [gs]etkeycode() is
 789  * defined. In this case, an array indexed by the scancode is used.
 790  */
 791 
 792 static unsigned int input_fetch_keycode(struct input_dev *dev,
 793                                         unsigned int index)
 794 {
 795         switch (dev->keycodesize) {
 796         case 1:
 797                 return ((u8 *)dev->keycode)[index];
 798 
 799         case 2:
 800                 return ((u16 *)dev->keycode)[index];
 801 
 802         default:
 803                 return ((u32 *)dev->keycode)[index];
 804         }
 805 }
 806 
 807 static int input_default_getkeycode(struct input_dev *dev,
 808                                     struct input_keymap_entry *ke)
 809 {
 810         unsigned int index;
 811         int error;
 812 
 813         if (!dev->keycodesize)
 814                 return -EINVAL;
 815 
 816         if (ke->flags & INPUT_KEYMAP_BY_INDEX)
 817                 index = ke->index;
 818         else {
 819                 error = input_scancode_to_scalar(ke, &index);
 820                 if (error)
 821                         return error;
 822         }
 823 
 824         if (index >= dev->keycodemax)
 825                 return -EINVAL;
 826 
 827         ke->keycode = input_fetch_keycode(dev, index);
 828         ke->index = index;
 829         ke->len = sizeof(index);
 830         memcpy(ke->scancode, &index, sizeof(index));
 831 
 832         return 0;
 833 }
 834 
 835 static int input_default_setkeycode(struct input_dev *dev,
 836                                     const struct input_keymap_entry *ke,
 837                                     unsigned int *old_keycode)
 838 {
 839         unsigned int index;
 840         int error;
 841         int i;
 842 
 843         if (!dev->keycodesize)
 844                 return -EINVAL;
 845 
 846         if (ke->flags & INPUT_KEYMAP_BY_INDEX) {
 847                 index = ke->index;
 848         } else {
 849                 error = input_scancode_to_scalar(ke, &index);
 850                 if (error)
 851                         return error;
 852         }
 853 
 854         if (index >= dev->keycodemax)
 855                 return -EINVAL;
 856 
 857         if (dev->keycodesize < sizeof(ke->keycode) &&
 858                         (ke->keycode >> (dev->keycodesize * 8)))
 859                 return -EINVAL;
 860 
 861         switch (dev->keycodesize) {
 862                 case 1: {
 863                         u8 *k = (u8 *)dev->keycode;
 864                         *old_keycode = k[index];
 865                         k[index] = ke->keycode;
 866                         break;
 867                 }
 868                 case 2: {
 869                         u16 *k = (u16 *)dev->keycode;
 870                         *old_keycode = k[index];
 871                         k[index] = ke->keycode;
 872                         break;
 873                 }
 874                 default: {
 875                         u32 *k = (u32 *)dev->keycode;
 876                         *old_keycode = k[index];
 877                         k[index] = ke->keycode;
 878                         break;
 879                 }
 880         }
 881 
 882         if (*old_keycode <= KEY_MAX) {
 883                 __clear_bit(*old_keycode, dev->keybit);
 884                 for (i = 0; i < dev->keycodemax; i++) {
 885                         if (input_fetch_keycode(dev, i) == *old_keycode) {
 886                                 __set_bit(*old_keycode, dev->keybit);
 887                                 /* Setting the bit twice is useless, so break */
 888                                 break;
 889                         }
 890                 }
 891         }
 892 
 893         __set_bit(ke->keycode, dev->keybit);
 894         return 0;
 895 }
 896 
 897 /**
 898  * input_get_keycode - retrieve keycode currently mapped to a given scancode
 899  * @dev: input device which keymap is being queried
 900  * @ke: keymap entry
 901  *
 902  * This function should be called by anyone interested in retrieving current
 903  * keymap. Presently evdev handlers use it.
 904  */
 905 int input_get_keycode(struct input_dev *dev, struct input_keymap_entry *ke)
 906 {
 907         unsigned long flags;
 908         int retval;
 909 
 910         spin_lock_irqsave(&dev->event_lock, flags);
 911         retval = dev->getkeycode(dev, ke);
 912         spin_unlock_irqrestore(&dev->event_lock, flags);
 913 
 914         return retval;
 915 }
 916 EXPORT_SYMBOL(input_get_keycode);
 917 
 918 /**
 919  * input_set_keycode - attribute a keycode to a given scancode
 920  * @dev: input device which keymap is being updated
 921  * @ke: new keymap entry
 922  *
 923  * This function should be called by anyone needing to update current
 924  * keymap. Presently keyboard and evdev handlers use it.
 925  */
 926 int input_set_keycode(struct input_dev *dev,
 927                       const struct input_keymap_entry *ke)
 928 {
 929         unsigned long flags;
 930         unsigned int old_keycode;
 931         int retval;
 932 
 933         if (ke->keycode > KEY_MAX)
 934                 return -EINVAL;
 935 
 936         spin_lock_irqsave(&dev->event_lock, flags);
 937 
 938         retval = dev->setkeycode(dev, ke, &old_keycode);
 939         if (retval)
 940                 goto out;
 941 
 942         /* Make sure KEY_RESERVED did not get enabled. */
 943         __clear_bit(KEY_RESERVED, dev->keybit);
 944 
 945         /*
 946          * Simulate keyup event if keycode is not present
 947          * in the keymap anymore
 948          */
 949         if (old_keycode > KEY_MAX) {
 950                 dev_warn(dev->dev.parent ?: &dev->dev,
 951                          "%s: got too big old keycode %#x\n",
 952                          __func__, old_keycode);
 953         } else if (test_bit(EV_KEY, dev->evbit) &&
 954                    !is_event_supported(old_keycode, dev->keybit, KEY_MAX) &&
 955                    __test_and_clear_bit(old_keycode, dev->key)) {
 956                 struct input_value vals[] =  {
 957                         { EV_KEY, old_keycode, 0 },
 958                         input_value_sync
 959                 };
 960 
 961                 input_pass_values(dev, vals, ARRAY_SIZE(vals));
 962         }
 963 
 964  out:
 965         spin_unlock_irqrestore(&dev->event_lock, flags);
 966 
 967         return retval;
 968 }
 969 EXPORT_SYMBOL(input_set_keycode);
 970 
 971 bool input_match_device_id(const struct input_dev *dev,
 972                            const struct input_device_id *id)
 973 {
 974         if (id->flags & INPUT_DEVICE_ID_MATCH_BUS)
 975                 if (id->bustype != dev->id.bustype)
 976                         return false;
 977 
 978         if (id->flags & INPUT_DEVICE_ID_MATCH_VENDOR)
 979                 if (id->vendor != dev->id.vendor)
 980                         return false;
 981 
 982         if (id->flags & INPUT_DEVICE_ID_MATCH_PRODUCT)
 983                 if (id->product != dev->id.product)
 984                         return false;
 985 
 986         if (id->flags & INPUT_DEVICE_ID_MATCH_VERSION)
 987                 if (id->version != dev->id.version)
 988                         return false;
 989 
 990         if (!bitmap_subset(id->evbit, dev->evbit, EV_MAX) ||
 991             !bitmap_subset(id->keybit, dev->keybit, KEY_MAX) ||
 992             !bitmap_subset(id->relbit, dev->relbit, REL_MAX) ||
 993             !bitmap_subset(id->absbit, dev->absbit, ABS_MAX) ||
 994             !bitmap_subset(id->mscbit, dev->mscbit, MSC_MAX) ||
 995             !bitmap_subset(id->ledbit, dev->ledbit, LED_MAX) ||
 996             !bitmap_subset(id->sndbit, dev->sndbit, SND_MAX) ||
 997             !bitmap_subset(id->ffbit, dev->ffbit, FF_MAX) ||
 998             !bitmap_subset(id->swbit, dev->swbit, SW_MAX) ||
 999             !bitmap_subset(id->propbit, dev->propbit, INPUT_PROP_MAX)) {
1000                 return false;
1001         }
1002 
1003         return true;
1004 }
1005 EXPORT_SYMBOL(input_match_device_id);
1006 
1007 static const struct input_device_id *input_match_device(struct input_handler *handler,
1008                                                         struct input_dev *dev)
1009 {
1010         const struct input_device_id *id;
1011 
1012         for (id = handler->id_table; id->flags || id->driver_info; id++) {
1013                 if (input_match_device_id(dev, id) &&
1014                     (!handler->match || handler->match(handler, dev))) {
1015                         return id;
1016                 }
1017         }
1018 
1019         return NULL;
1020 }
1021 
1022 static int input_attach_handler(struct input_dev *dev, struct input_handler *handler)
1023 {
1024         const struct input_device_id *id;
1025         int error;
1026 
1027         id = input_match_device(handler, dev);
1028         if (!id)
1029                 return -ENODEV;
1030 
1031         error = handler->connect(handler, dev, id);
1032         if (error && error != -ENODEV)
1033                 pr_err("failed to attach handler %s to device %s, error: %d\n",
1034                        handler->name, kobject_name(&dev->dev.kobj), error);
1035 
1036         return error;
1037 }
1038 
1039 #ifdef CONFIG_COMPAT
1040 
1041 static int input_bits_to_string(char *buf, int buf_size,
1042                                 unsigned long bits, bool skip_empty)
1043 {
1044         int len = 0;
1045 
1046         if (in_compat_syscall()) {
1047                 u32 dword = bits >> 32;
1048                 if (dword || !skip_empty)
1049                         len += snprintf(buf, buf_size, "%x ", dword);
1050 
1051                 dword = bits & 0xffffffffUL;
1052                 if (dword || !skip_empty || len)
1053                         len += snprintf(buf + len, max(buf_size - len, 0),
1054                                         "%x", dword);
1055         } else {
1056                 if (bits || !skip_empty)
1057                         len += snprintf(buf, buf_size, "%lx", bits);
1058         }
1059 
1060         return len;
1061 }
1062 
1063 #else /* !CONFIG_COMPAT */
1064 
1065 static int input_bits_to_string(char *buf, int buf_size,
1066                                 unsigned long bits, bool skip_empty)
1067 {
1068         return bits || !skip_empty ?
1069                 snprintf(buf, buf_size, "%lx", bits) : 0;
1070 }
1071 
1072 #endif
1073 
1074 #ifdef CONFIG_PROC_FS
1075 
1076 static struct proc_dir_entry *proc_bus_input_dir;
1077 static DECLARE_WAIT_QUEUE_HEAD(input_devices_poll_wait);
1078 static int input_devices_state;
1079 
1080 static inline void input_wakeup_procfs_readers(void)
1081 {
1082         input_devices_state++;
1083         wake_up(&input_devices_poll_wait);
1084 }
1085 
1086 static __poll_t input_proc_devices_poll(struct file *file, poll_table *wait)
1087 {
1088         poll_wait(file, &input_devices_poll_wait, wait);
1089         if (file->f_version != input_devices_state) {
1090                 file->f_version = input_devices_state;
1091                 return EPOLLIN | EPOLLRDNORM;
1092         }
1093 
1094         return 0;
1095 }
1096 
1097 union input_seq_state {
1098         struct {
1099                 unsigned short pos;
1100                 bool mutex_acquired;
1101         };
1102         void *p;
1103 };
1104 
1105 static void *input_devices_seq_start(struct seq_file *seq, loff_t *pos)
1106 {
1107         union input_seq_state *state = (union input_seq_state *)&seq->private;
1108         int error;
1109 
1110         /* We need to fit into seq->private pointer */
1111         BUILD_BUG_ON(sizeof(union input_seq_state) != sizeof(seq->private));
1112 
1113         error = mutex_lock_interruptible(&input_mutex);
1114         if (error) {
1115                 state->mutex_acquired = false;
1116                 return ERR_PTR(error);
1117         }
1118 
1119         state->mutex_acquired = true;
1120 
1121         return seq_list_start(&input_dev_list, *pos);
1122 }
1123 
1124 static void *input_devices_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1125 {
1126         return seq_list_next(v, &input_dev_list, pos);
1127 }
1128 
1129 static void input_seq_stop(struct seq_file *seq, void *v)
1130 {
1131         union input_seq_state *state = (union input_seq_state *)&seq->private;
1132 
1133         if (state->mutex_acquired)
1134                 mutex_unlock(&input_mutex);
1135 }
1136 
1137 static void input_seq_print_bitmap(struct seq_file *seq, const char *name,
1138                                    unsigned long *bitmap, int max)
1139 {
1140         int i;
1141         bool skip_empty = true;
1142         char buf[18];
1143 
1144         seq_printf(seq, "B: %s=", name);
1145 
1146         for (i = BITS_TO_LONGS(max) - 1; i >= 0; i--) {
1147                 if (input_bits_to_string(buf, sizeof(buf),
1148                                          bitmap[i], skip_empty)) {
1149                         skip_empty = false;
1150                         seq_printf(seq, "%s%s", buf, i > 0 ? " " : "");
1151                 }
1152         }
1153 
1154         /*
1155          * If no output was produced print a single 0.
1156          */
1157         if (skip_empty)
1158                 seq_putc(seq, '0');
1159 
1160         seq_putc(seq, '\n');
1161 }
1162 
1163 static int input_devices_seq_show(struct seq_file *seq, void *v)
1164 {
1165         struct input_dev *dev = container_of(v, struct input_dev, node);
1166         const char *path = kobject_get_path(&dev->dev.kobj, GFP_KERNEL);
1167         struct input_handle *handle;
1168 
1169         seq_printf(seq, "I: Bus=%04x Vendor=%04x Product=%04x Version=%04x\n",
1170                    dev->id.bustype, dev->id.vendor, dev->id.product, dev->id.version);
1171 
1172         seq_printf(seq, "N: Name=\"%s\"\n", dev->name ? dev->name : "");
1173         seq_printf(seq, "P: Phys=%s\n", dev->phys ? dev->phys : "");
1174         seq_printf(seq, "S: Sysfs=%s\n", path ? path : "");
1175         seq_printf(seq, "U: Uniq=%s\n", dev->uniq ? dev->uniq : "");
1176         seq_puts(seq, "H: Handlers=");
1177 
1178         list_for_each_entry(handle, &dev->h_list, d_node)
1179                 seq_printf(seq, "%s ", handle->name);
1180         seq_putc(seq, '\n');
1181 
1182         input_seq_print_bitmap(seq, "PROP", dev->propbit, INPUT_PROP_MAX);
1183 
1184         input_seq_print_bitmap(seq, "EV", dev->evbit, EV_MAX);
1185         if (test_bit(EV_KEY, dev->evbit))
1186                 input_seq_print_bitmap(seq, "KEY", dev->keybit, KEY_MAX);
1187         if (test_bit(EV_REL, dev->evbit))
1188                 input_seq_print_bitmap(seq, "REL", dev->relbit, REL_MAX);
1189         if (test_bit(EV_ABS, dev->evbit))
1190                 input_seq_print_bitmap(seq, "ABS", dev->absbit, ABS_MAX);
1191         if (test_bit(EV_MSC, dev->evbit))
1192                 input_seq_print_bitmap(seq, "MSC", dev->mscbit, MSC_MAX);
1193         if (test_bit(EV_LED, dev->evbit))
1194                 input_seq_print_bitmap(seq, "LED", dev->ledbit, LED_MAX);
1195         if (test_bit(EV_SND, dev->evbit))
1196                 input_seq_print_bitmap(seq, "SND", dev->sndbit, SND_MAX);
1197         if (test_bit(EV_FF, dev->evbit))
1198                 input_seq_print_bitmap(seq, "FF", dev->ffbit, FF_MAX);
1199         if (test_bit(EV_SW, dev->evbit))
1200                 input_seq_print_bitmap(seq, "SW", dev->swbit, SW_MAX);
1201 
1202         seq_putc(seq, '\n');
1203 
1204         kfree(path);
1205         return 0;
1206 }
1207 
1208 static const struct seq_operations input_devices_seq_ops = {
1209         .start  = input_devices_seq_start,
1210         .next   = input_devices_seq_next,
1211         .stop   = input_seq_stop,
1212         .show   = input_devices_seq_show,
1213 };
1214 
1215 static int input_proc_devices_open(struct inode *inode, struct file *file)
1216 {
1217         return seq_open(file, &input_devices_seq_ops);
1218 }
1219 
1220 static const struct file_operations input_devices_fileops = {
1221         .owner          = THIS_MODULE,
1222         .open           = input_proc_devices_open,
1223         .poll           = input_proc_devices_poll,
1224         .read           = seq_read,
1225         .llseek         = seq_lseek,
1226         .release        = seq_release,
1227 };
1228 
1229 static void *input_handlers_seq_start(struct seq_file *seq, loff_t *pos)
1230 {
1231         union input_seq_state *state = (union input_seq_state *)&seq->private;
1232         int error;
1233 
1234         /* We need to fit into seq->private pointer */
1235         BUILD_BUG_ON(sizeof(union input_seq_state) != sizeof(seq->private));
1236 
1237         error = mutex_lock_interruptible(&input_mutex);
1238         if (error) {
1239                 state->mutex_acquired = false;
1240                 return ERR_PTR(error);
1241         }
1242 
1243         state->mutex_acquired = true;
1244         state->pos = *pos;
1245 
1246         return seq_list_start(&input_handler_list, *pos);
1247 }
1248 
1249 static void *input_handlers_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1250 {
1251         union input_seq_state *state = (union input_seq_state *)&seq->private;
1252 
1253         state->pos = *pos + 1;
1254         return seq_list_next(v, &input_handler_list, pos);
1255 }
1256 
1257 static int input_handlers_seq_show(struct seq_file *seq, void *v)
1258 {
1259         struct input_handler *handler = container_of(v, struct input_handler, node);
1260         union input_seq_state *state = (union input_seq_state *)&seq->private;
1261 
1262         seq_printf(seq, "N: Number=%u Name=%s", state->pos, handler->name);
1263         if (handler->filter)
1264                 seq_puts(seq, " (filter)");
1265         if (handler->legacy_minors)
1266                 seq_printf(seq, " Minor=%d", handler->minor);
1267         seq_putc(seq, '\n');
1268 
1269         return 0;
1270 }
1271 
1272 static const struct seq_operations input_handlers_seq_ops = {
1273         .start  = input_handlers_seq_start,
1274         .next   = input_handlers_seq_next,
1275         .stop   = input_seq_stop,
1276         .show   = input_handlers_seq_show,
1277 };
1278 
1279 static int input_proc_handlers_open(struct inode *inode, struct file *file)
1280 {
1281         return seq_open(file, &input_handlers_seq_ops);
1282 }
1283 
1284 static const struct file_operations input_handlers_fileops = {
1285         .owner          = THIS_MODULE,
1286         .open           = input_proc_handlers_open,
1287         .read           = seq_read,
1288         .llseek         = seq_lseek,
1289         .release        = seq_release,
1290 };
1291 
1292 static int __init input_proc_init(void)
1293 {
1294         struct proc_dir_entry *entry;
1295 
1296         proc_bus_input_dir = proc_mkdir("bus/input", NULL);
1297         if (!proc_bus_input_dir)
1298                 return -ENOMEM;
1299 
1300         entry = proc_create("devices", 0, proc_bus_input_dir,
1301                             &input_devices_fileops);
1302         if (!entry)
1303                 goto fail1;
1304 
1305         entry = proc_create("handlers", 0, proc_bus_input_dir,
1306                             &input_handlers_fileops);
1307         if (!entry)
1308                 goto fail2;
1309 
1310         return 0;
1311 
1312  fail2: remove_proc_entry("devices", proc_bus_input_dir);
1313  fail1: remove_proc_entry("bus/input", NULL);
1314         return -ENOMEM;
1315 }
1316 
1317 static void input_proc_exit(void)
1318 {
1319         remove_proc_entry("devices", proc_bus_input_dir);
1320         remove_proc_entry("handlers", proc_bus_input_dir);
1321         remove_proc_entry("bus/input", NULL);
1322 }
1323 
1324 #else /* !CONFIG_PROC_FS */
1325 static inline void input_wakeup_procfs_readers(void) { }
1326 static inline int input_proc_init(void) { return 0; }
1327 static inline void input_proc_exit(void) { }
1328 #endif
1329 
1330 #define INPUT_DEV_STRING_ATTR_SHOW(name)                                \
1331 static ssize_t input_dev_show_##name(struct device *dev,                \
1332                                      struct device_attribute *attr,     \
1333                                      char *buf)                         \
1334 {                                                                       \
1335         struct input_dev *input_dev = to_input_dev(dev);                \
1336                                                                         \
1337         return scnprintf(buf, PAGE_SIZE, "%s\n",                        \
1338                          input_dev->name ? input_dev->name : "");       \
1339 }                                                                       \
1340 static DEVICE_ATTR(name, S_IRUGO, input_dev_show_##name, NULL)
1341 
1342 INPUT_DEV_STRING_ATTR_SHOW(name);
1343 INPUT_DEV_STRING_ATTR_SHOW(phys);
1344 INPUT_DEV_STRING_ATTR_SHOW(uniq);
1345 
1346 static int input_print_modalias_bits(char *buf, int size,
1347                                      char name, unsigned long *bm,
1348                                      unsigned int min_bit, unsigned int max_bit)
1349 {
1350         int len = 0, i;
1351 
1352         len += snprintf(buf, max(size, 0), "%c", name);
1353         for (i = min_bit; i < max_bit; i++)
1354                 if (bm[BIT_WORD(i)] & BIT_MASK(i))
1355                         len += snprintf(buf + len, max(size - len, 0), "%X,", i);
1356         return len;
1357 }
1358 
1359 static int input_print_modalias(char *buf, int size, struct input_dev *id,
1360                                 int add_cr)
1361 {
1362         int len;
1363 
1364         len = snprintf(buf, max(size, 0),
1365                        "input:b%04Xv%04Xp%04Xe%04X-",
1366                        id->id.bustype, id->id.vendor,
1367                        id->id.product, id->id.version);
1368 
1369         len += input_print_modalias_bits(buf + len, size - len,
1370                                 'e', id->evbit, 0, EV_MAX);
1371         len += input_print_modalias_bits(buf + len, size - len,
1372                                 'k', id->keybit, KEY_MIN_INTERESTING, KEY_MAX);
1373         len += input_print_modalias_bits(buf + len, size - len,
1374                                 'r', id->relbit, 0, REL_MAX);
1375         len += input_print_modalias_bits(buf + len, size - len,
1376                                 'a', id->absbit, 0, ABS_MAX);
1377         len += input_print_modalias_bits(buf + len, size - len,
1378                                 'm', id->mscbit, 0, MSC_MAX);
1379         len += input_print_modalias_bits(buf + len, size - len,
1380                                 'l', id->ledbit, 0, LED_MAX);
1381         len += input_print_modalias_bits(buf + len, size - len,
1382                                 's', id->sndbit, 0, SND_MAX);
1383         len += input_print_modalias_bits(buf + len, size - len,
1384                                 'f', id->ffbit, 0, FF_MAX);
1385         len += input_print_modalias_bits(buf + len, size - len,
1386                                 'w', id->swbit, 0, SW_MAX);
1387 
1388         if (add_cr)
1389                 len += snprintf(buf + len, max(size - len, 0), "\n");
1390 
1391         return len;
1392 }
1393 
1394 static ssize_t input_dev_show_modalias(struct device *dev,
1395                                        struct device_attribute *attr,
1396                                        char *buf)
1397 {
1398         struct input_dev *id = to_input_dev(dev);
1399         ssize_t len;
1400 
1401         len = input_print_modalias(buf, PAGE_SIZE, id, 1);
1402 
1403         return min_t(int, len, PAGE_SIZE);
1404 }
1405 static DEVICE_ATTR(modalias, S_IRUGO, input_dev_show_modalias, NULL);
1406 
1407 static int input_print_bitmap(char *buf, int buf_size, unsigned long *bitmap,
1408                               int max, int add_cr);
1409 
1410 static ssize_t input_dev_show_properties(struct device *dev,
1411                                          struct device_attribute *attr,
1412                                          char *buf)
1413 {
1414         struct input_dev *input_dev = to_input_dev(dev);
1415         int len = input_print_bitmap(buf, PAGE_SIZE, input_dev->propbit,
1416                                      INPUT_PROP_MAX, true);
1417         return min_t(int, len, PAGE_SIZE);
1418 }
1419 static DEVICE_ATTR(properties, S_IRUGO, input_dev_show_properties, NULL);
1420 
1421 static struct attribute *input_dev_attrs[] = {
1422         &dev_attr_name.attr,
1423         &dev_attr_phys.attr,
1424         &dev_attr_uniq.attr,
1425         &dev_attr_modalias.attr,
1426         &dev_attr_properties.attr,
1427         NULL
1428 };
1429 
1430 static const struct attribute_group input_dev_attr_group = {
1431         .attrs  = input_dev_attrs,
1432 };
1433 
1434 #define INPUT_DEV_ID_ATTR(name)                                         \
1435 static ssize_t input_dev_show_id_##name(struct device *dev,             \
1436                                         struct device_attribute *attr,  \
1437                                         char *buf)                      \
1438 {                                                                       \
1439         struct input_dev *input_dev = to_input_dev(dev);                \
1440         return scnprintf(buf, PAGE_SIZE, "%04x\n", input_dev->id.name); \
1441 }                                                                       \
1442 static DEVICE_ATTR(name, S_IRUGO, input_dev_show_id_##name, NULL)
1443 
1444 INPUT_DEV_ID_ATTR(bustype);
1445 INPUT_DEV_ID_ATTR(vendor);
1446 INPUT_DEV_ID_ATTR(product);
1447 INPUT_DEV_ID_ATTR(version);
1448 
1449 static struct attribute *input_dev_id_attrs[] = {
1450         &dev_attr_bustype.attr,
1451         &dev_attr_vendor.attr,
1452         &dev_attr_product.attr,
1453         &dev_attr_version.attr,
1454         NULL
1455 };
1456 
1457 static const struct attribute_group input_dev_id_attr_group = {
1458         .name   = "id",
1459         .attrs  = input_dev_id_attrs,
1460 };
1461 
1462 static int input_print_bitmap(char *buf, int buf_size, unsigned long *bitmap,
1463                               int max, int add_cr)
1464 {
1465         int i;
1466         int len = 0;
1467         bool skip_empty = true;
1468 
1469         for (i = BITS_TO_LONGS(max) - 1; i >= 0; i--) {
1470                 len += input_bits_to_string(buf + len, max(buf_size - len, 0),
1471                                             bitmap[i], skip_empty);
1472                 if (len) {
1473                         skip_empty = false;
1474                         if (i > 0)
1475                                 len += snprintf(buf + len, max(buf_size - len, 0), " ");
1476                 }
1477         }
1478 
1479         /*
1480          * If no output was produced print a single 0.
1481          */
1482         if (len == 0)
1483                 len = snprintf(buf, buf_size, "%d", 0);
1484 
1485         if (add_cr)
1486                 len += snprintf(buf + len, max(buf_size - len, 0), "\n");
1487 
1488         return len;
1489 }
1490 
1491 #define INPUT_DEV_CAP_ATTR(ev, bm)                                      \
1492 static ssize_t input_dev_show_cap_##bm(struct device *dev,              \
1493                                        struct device_attribute *attr,   \
1494                                        char *buf)                       \
1495 {                                                                       \
1496         struct input_dev *input_dev = to_input_dev(dev);                \
1497         int len = input_print_bitmap(buf, PAGE_SIZE,                    \
1498                                      input_dev->bm##bit, ev##_MAX,      \
1499                                      true);                             \
1500         return min_t(int, len, PAGE_SIZE);                              \
1501 }                                                                       \
1502 static DEVICE_ATTR(bm, S_IRUGO, input_dev_show_cap_##bm, NULL)
1503 
1504 INPUT_DEV_CAP_ATTR(EV, ev);
1505 INPUT_DEV_CAP_ATTR(KEY, key);
1506 INPUT_DEV_CAP_ATTR(REL, rel);
1507 INPUT_DEV_CAP_ATTR(ABS, abs);
1508 INPUT_DEV_CAP_ATTR(MSC, msc);
1509 INPUT_DEV_CAP_ATTR(LED, led);
1510 INPUT_DEV_CAP_ATTR(SND, snd);
1511 INPUT_DEV_CAP_ATTR(FF, ff);
1512 INPUT_DEV_CAP_ATTR(SW, sw);
1513 
1514 static struct attribute *input_dev_caps_attrs[] = {
1515         &dev_attr_ev.attr,
1516         &dev_attr_key.attr,
1517         &dev_attr_rel.attr,
1518         &dev_attr_abs.attr,
1519         &dev_attr_msc.attr,
1520         &dev_attr_led.attr,
1521         &dev_attr_snd.attr,
1522         &dev_attr_ff.attr,
1523         &dev_attr_sw.attr,
1524         NULL
1525 };
1526 
1527 static const struct attribute_group input_dev_caps_attr_group = {
1528         .name   = "capabilities",
1529         .attrs  = input_dev_caps_attrs,
1530 };
1531 
1532 static const struct attribute_group *input_dev_attr_groups[] = {
1533         &input_dev_attr_group,
1534         &input_dev_id_attr_group,
1535         &input_dev_caps_attr_group,
1536         &input_poller_attribute_group,
1537         NULL
1538 };
1539 
1540 static void input_dev_release(struct device *device)
1541 {
1542         struct input_dev *dev = to_input_dev(device);
1543 
1544         input_ff_destroy(dev);
1545         input_mt_destroy_slots(dev);
1546         kfree(dev->poller);
1547         kfree(dev->absinfo);
1548         kfree(dev->vals);
1549         kfree(dev);
1550 
1551         module_put(THIS_MODULE);
1552 }
1553 
1554 /*
1555  * Input uevent interface - loading event handlers based on
1556  * device bitfields.
1557  */
1558 static int input_add_uevent_bm_var(struct kobj_uevent_env *env,
1559                                    const char *name, unsigned long *bitmap, int max)
1560 {
1561         int len;
1562 
1563         if (add_uevent_var(env, "%s", name))
1564                 return -ENOMEM;
1565 
1566         len = input_print_bitmap(&env->buf[env->buflen - 1],
1567                                  sizeof(env->buf) - env->buflen,
1568                                  bitmap, max, false);
1569         if (len >= (sizeof(env->buf) - env->buflen))
1570                 return -ENOMEM;
1571 
1572         env->buflen += len;
1573         return 0;
1574 }
1575 
1576 static int input_add_uevent_modalias_var(struct kobj_uevent_env *env,
1577                                          struct input_dev *dev)
1578 {
1579         int len;
1580 
1581         if (add_uevent_var(env, "MODALIAS="))
1582                 return -ENOMEM;
1583 
1584         len = input_print_modalias(&env->buf[env->buflen - 1],
1585                                    sizeof(env->buf) - env->buflen,
1586                                    dev, 0);
1587         if (len >= (sizeof(env->buf) - env->buflen))
1588                 return -ENOMEM;
1589 
1590         env->buflen += len;
1591         return 0;
1592 }
1593 
1594 #define INPUT_ADD_HOTPLUG_VAR(fmt, val...)                              \
1595         do {                                                            \
1596                 int err = add_uevent_var(env, fmt, val);                \
1597                 if (err)                                                \
1598                         return err;                                     \
1599         } while (0)
1600 
1601 #define INPUT_ADD_HOTPLUG_BM_VAR(name, bm, max)                         \
1602         do {                                                            \
1603                 int err = input_add_uevent_bm_var(env, name, bm, max);  \
1604                 if (err)                                                \
1605                         return err;                                     \
1606         } while (0)
1607 
1608 #define INPUT_ADD_HOTPLUG_MODALIAS_VAR(dev)                             \
1609         do {                                                            \
1610                 int err = input_add_uevent_modalias_var(env, dev);      \
1611                 if (err)                                                \
1612                         return err;                                     \
1613         } while (0)
1614 
1615 static int input_dev_uevent(struct device *device, struct kobj_uevent_env *env)
1616 {
1617         struct input_dev *dev = to_input_dev(device);
1618 
1619         INPUT_ADD_HOTPLUG_VAR("PRODUCT=%x/%x/%x/%x",
1620                                 dev->id.bustype, dev->id.vendor,
1621                                 dev->id.product, dev->id.version);
1622         if (dev->name)
1623                 INPUT_ADD_HOTPLUG_VAR("NAME=\"%s\"", dev->name);
1624         if (dev->phys)
1625                 INPUT_ADD_HOTPLUG_VAR("PHYS=\"%s\"", dev->phys);
1626         if (dev->uniq)
1627                 INPUT_ADD_HOTPLUG_VAR("UNIQ=\"%s\"", dev->uniq);
1628 
1629         INPUT_ADD_HOTPLUG_BM_VAR("PROP=", dev->propbit, INPUT_PROP_MAX);
1630 
1631         INPUT_ADD_HOTPLUG_BM_VAR("EV=", dev->evbit, EV_MAX);
1632         if (test_bit(EV_KEY, dev->evbit))
1633                 INPUT_ADD_HOTPLUG_BM_VAR("KEY=", dev->keybit, KEY_MAX);
1634         if (test_bit(EV_REL, dev->evbit))
1635                 INPUT_ADD_HOTPLUG_BM_VAR("REL=", dev->relbit, REL_MAX);
1636         if (test_bit(EV_ABS, dev->evbit))
1637                 INPUT_ADD_HOTPLUG_BM_VAR("ABS=", dev->absbit, ABS_MAX);
1638         if (test_bit(EV_MSC, dev->evbit))
1639                 INPUT_ADD_HOTPLUG_BM_VAR("MSC=", dev->mscbit, MSC_MAX);
1640         if (test_bit(EV_LED, dev->evbit))
1641                 INPUT_ADD_HOTPLUG_BM_VAR("LED=", dev->ledbit, LED_MAX);
1642         if (test_bit(EV_SND, dev->evbit))
1643                 INPUT_ADD_HOTPLUG_BM_VAR("SND=", dev->sndbit, SND_MAX);
1644         if (test_bit(EV_FF, dev->evbit))
1645                 INPUT_ADD_HOTPLUG_BM_VAR("FF=", dev->ffbit, FF_MAX);
1646         if (test_bit(EV_SW, dev->evbit))
1647                 INPUT_ADD_HOTPLUG_BM_VAR("SW=", dev->swbit, SW_MAX);
1648 
1649         INPUT_ADD_HOTPLUG_MODALIAS_VAR(dev);
1650 
1651         return 0;
1652 }
1653 
1654 #define INPUT_DO_TOGGLE(dev, type, bits, on)                            \
1655         do {                                                            \
1656                 int i;                                                  \
1657                 bool active;                                            \
1658                                                                         \
1659                 if (!test_bit(EV_##type, dev->evbit))                   \
1660                         break;                                          \
1661                                                                         \
1662                 for_each_set_bit(i, dev->bits##bit, type##_CNT) {       \
1663                         active = test_bit(i, dev->bits);                \
1664                         if (!active && !on)                             \
1665                                 continue;                               \
1666                                                                         \
1667                         dev->event(dev, EV_##type, i, on ? active : 0); \
1668                 }                                                       \
1669         } while (0)
1670 
1671 static void input_dev_toggle(struct input_dev *dev, bool activate)
1672 {
1673         if (!dev->event)
1674                 return;
1675 
1676         INPUT_DO_TOGGLE(dev, LED, led, activate);
1677         INPUT_DO_TOGGLE(dev, SND, snd, activate);
1678 
1679         if (activate && test_bit(EV_REP, dev->evbit)) {
1680                 dev->event(dev, EV_REP, REP_PERIOD, dev->rep[REP_PERIOD]);
1681                 dev->event(dev, EV_REP, REP_DELAY, dev->rep[REP_DELAY]);
1682         }
1683 }
1684 
1685 /**
1686  * input_reset_device() - reset/restore the state of input device
1687  * @dev: input device whose state needs to be reset
1688  *
1689  * This function tries to reset the state of an opened input device and
1690  * bring internal state and state if the hardware in sync with each other.
1691  * We mark all keys as released, restore LED state, repeat rate, etc.
1692  */
1693 void input_reset_device(struct input_dev *dev)
1694 {
1695         unsigned long flags;
1696 
1697         mutex_lock(&dev->mutex);
1698         spin_lock_irqsave(&dev->event_lock, flags);
1699 
1700         input_dev_toggle(dev, true);
1701         input_dev_release_keys(dev);
1702 
1703         spin_unlock_irqrestore(&dev->event_lock, flags);
1704         mutex_unlock(&dev->mutex);
1705 }
1706 EXPORT_SYMBOL(input_reset_device);
1707 
1708 #ifdef CONFIG_PM_SLEEP
1709 static int input_dev_suspend(struct device *dev)
1710 {
1711         struct input_dev *input_dev = to_input_dev(dev);
1712 
1713         spin_lock_irq(&input_dev->event_lock);
1714 
1715         /*
1716          * Keys that are pressed now are unlikely to be
1717          * still pressed when we resume.
1718          */
1719         input_dev_release_keys(input_dev);
1720 
1721         /* Turn off LEDs and sounds, if any are active. */
1722         input_dev_toggle(input_dev, false);
1723 
1724         spin_unlock_irq(&input_dev->event_lock);
1725 
1726         return 0;
1727 }
1728 
1729 static int input_dev_resume(struct device *dev)
1730 {
1731         struct input_dev *input_dev = to_input_dev(dev);
1732 
1733         spin_lock_irq(&input_dev->event_lock);
1734 
1735         /* Restore state of LEDs and sounds, if any were active. */
1736         input_dev_toggle(input_dev, true);
1737 
1738         spin_unlock_irq(&input_dev->event_lock);
1739 
1740         return 0;
1741 }
1742 
1743 static int input_dev_freeze(struct device *dev)
1744 {
1745         struct input_dev *input_dev = to_input_dev(dev);
1746 
1747         spin_lock_irq(&input_dev->event_lock);
1748 
1749         /*
1750          * Keys that are pressed now are unlikely to be
1751          * still pressed when we resume.
1752          */
1753         input_dev_release_keys(input_dev);
1754 
1755         spin_unlock_irq(&input_dev->event_lock);
1756 
1757         return 0;
1758 }
1759 
1760 static int input_dev_poweroff(struct device *dev)
1761 {
1762         struct input_dev *input_dev = to_input_dev(dev);
1763 
1764         spin_lock_irq(&input_dev->event_lock);
1765 
1766         /* Turn off LEDs and sounds, if any are active. */
1767         input_dev_toggle(input_dev, false);
1768 
1769         spin_unlock_irq(&input_dev->event_lock);
1770 
1771         return 0;
1772 }
1773 
1774 static const struct dev_pm_ops input_dev_pm_ops = {
1775         .suspend        = input_dev_suspend,
1776         .resume         = input_dev_resume,
1777         .freeze         = input_dev_freeze,
1778         .poweroff       = input_dev_poweroff,
1779         .restore        = input_dev_resume,
1780 };
1781 #endif /* CONFIG_PM */
1782 
1783 static const struct device_type input_dev_type = {
1784         .groups         = input_dev_attr_groups,
1785         .release        = input_dev_release,
1786         .uevent         = input_dev_uevent,
1787 #ifdef CONFIG_PM_SLEEP
1788         .pm             = &input_dev_pm_ops,
1789 #endif
1790 };
1791 
1792 static char *input_devnode(struct device *dev, umode_t *mode)
1793 {
1794         return kasprintf(GFP_KERNEL, "input/%s", dev_name(dev));
1795 }
1796 
1797 struct class input_class = {
1798         .name           = "input",
1799         .devnode        = input_devnode,
1800 };
1801 EXPORT_SYMBOL_GPL(input_class);
1802 
1803 /**
1804  * input_allocate_device - allocate memory for new input device
1805  *
1806  * Returns prepared struct input_dev or %NULL.
1807  *
1808  * NOTE: Use input_free_device() to free devices that have not been
1809  * registered; input_unregister_device() should be used for already
1810  * registered devices.
1811  */
1812 struct input_dev *input_allocate_device(void)
1813 {
1814         static atomic_t input_no = ATOMIC_INIT(-1);
1815         struct input_dev *dev;
1816 
1817         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1818         if (dev) {
1819                 dev->dev.type = &input_dev_type;
1820                 dev->dev.class = &input_class;
1821                 device_initialize(&dev->dev);
1822                 mutex_init(&dev->mutex);
1823                 spin_lock_init(&dev->event_lock);
1824                 timer_setup(&dev->timer, NULL, 0);
1825                 INIT_LIST_HEAD(&dev->h_list);
1826                 INIT_LIST_HEAD(&dev->node);
1827 
1828                 dev_set_name(&dev->dev, "input%lu",
1829                              (unsigned long)atomic_inc_return(&input_no));
1830 
1831                 __module_get(THIS_MODULE);
1832         }
1833 
1834         return dev;
1835 }
1836 EXPORT_SYMBOL(input_allocate_device);
1837 
1838 struct input_devres {
1839         struct input_dev *input;
1840 };
1841 
1842 static int devm_input_device_match(struct device *dev, void *res, void *data)
1843 {
1844         struct input_devres *devres = res;
1845 
1846         return devres->input == data;
1847 }
1848 
1849 static void devm_input_device_release(struct device *dev, void *res)
1850 {
1851         struct input_devres *devres = res;
1852         struct input_dev *input = devres->input;
1853 
1854         dev_dbg(dev, "%s: dropping reference to %s\n",
1855                 __func__, dev_name(&input->dev));
1856         input_put_device(input);
1857 }
1858 
1859 /**
1860  * devm_input_allocate_device - allocate managed input device
1861  * @dev: device owning the input device being created
1862  *
1863  * Returns prepared struct input_dev or %NULL.
1864  *
1865  * Managed input devices do not need to be explicitly unregistered or
1866  * freed as it will be done automatically when owner device unbinds from
1867  * its driver (or binding fails). Once managed input device is allocated,
1868  * it is ready to be set up and registered in the same fashion as regular
1869  * input device. There are no special devm_input_device_[un]register()
1870  * variants, regular ones work with both managed and unmanaged devices,
1871  * should you need them. In most cases however, managed input device need
1872  * not be explicitly unregistered or freed.
1873  *
1874  * NOTE: the owner device is set up as parent of input device and users
1875  * should not override it.
1876  */
1877 struct input_dev *devm_input_allocate_device(struct device *dev)
1878 {
1879         struct input_dev *input;
1880         struct input_devres *devres;
1881 
1882         devres = devres_alloc(devm_input_device_release,
1883                               sizeof(*devres), GFP_KERNEL);
1884         if (!devres)
1885                 return NULL;
1886 
1887         input = input_allocate_device();
1888         if (!input) {
1889                 devres_free(devres);
1890                 return NULL;
1891         }
1892 
1893         input->dev.parent = dev;
1894         input->devres_managed = true;
1895 
1896         devres->input = input;
1897         devres_add(dev, devres);
1898 
1899         return input;
1900 }
1901 EXPORT_SYMBOL(devm_input_allocate_device);
1902 
1903 /**
1904  * input_free_device - free memory occupied by input_dev structure
1905  * @dev: input device to free
1906  *
1907  * This function should only be used if input_register_device()
1908  * was not called yet or if it failed. Once device was registered
1909  * use input_unregister_device() and memory will be freed once last
1910  * reference to the device is dropped.
1911  *
1912  * Device should be allocated by input_allocate_device().
1913  *
1914  * NOTE: If there are references to the input device then memory
1915  * will not be freed until last reference is dropped.
1916  */
1917 void input_free_device(struct input_dev *dev)
1918 {
1919         if (dev) {
1920                 if (dev->devres_managed)
1921                         WARN_ON(devres_destroy(dev->dev.parent,
1922                                                 devm_input_device_release,
1923                                                 devm_input_device_match,
1924                                                 dev));
1925                 input_put_device(dev);
1926         }
1927 }
1928 EXPORT_SYMBOL(input_free_device);
1929 
1930 /**
1931  * input_set_timestamp - set timestamp for input events
1932  * @dev: input device to set timestamp for
1933  * @timestamp: the time at which the event has occurred
1934  *   in CLOCK_MONOTONIC
1935  *
1936  * This function is intended to provide to the input system a more
1937  * accurate time of when an event actually occurred. The driver should
1938  * call this function as soon as a timestamp is acquired ensuring
1939  * clock conversions in input_set_timestamp are done correctly.
1940  *
1941  * The system entering suspend state between timestamp acquisition and
1942  * calling input_set_timestamp can result in inaccurate conversions.
1943  */
1944 void input_set_timestamp(struct input_dev *dev, ktime_t timestamp)
1945 {
1946         dev->timestamp[INPUT_CLK_MONO] = timestamp;
1947         dev->timestamp[INPUT_CLK_REAL] = ktime_mono_to_real(timestamp);
1948         dev->timestamp[INPUT_CLK_BOOT] = ktime_mono_to_any(timestamp,
1949                                                            TK_OFFS_BOOT);
1950 }
1951 EXPORT_SYMBOL(input_set_timestamp);
1952 
1953 /**
1954  * input_get_timestamp - get timestamp for input events
1955  * @dev: input device to get timestamp from
1956  *
1957  * A valid timestamp is a timestamp of non-zero value.
1958  */
1959 ktime_t *input_get_timestamp(struct input_dev *dev)
1960 {
1961         const ktime_t invalid_timestamp = ktime_set(0, 0);
1962 
1963         if (!ktime_compare(dev->timestamp[INPUT_CLK_MONO], invalid_timestamp))
1964                 input_set_timestamp(dev, ktime_get());
1965 
1966         return dev->timestamp;
1967 }
1968 EXPORT_SYMBOL(input_get_timestamp);
1969 
1970 /**
1971  * input_set_capability - mark device as capable of a certain event
1972  * @dev: device that is capable of emitting or accepting event
1973  * @type: type of the event (EV_KEY, EV_REL, etc...)
1974  * @code: event code
1975  *
1976  * In addition to setting up corresponding bit in appropriate capability
1977  * bitmap the function also adjusts dev->evbit.
1978  */
1979 void input_set_capability(struct input_dev *dev, unsigned int type, unsigned int code)
1980 {
1981         switch (type) {
1982         case EV_KEY:
1983                 __set_bit(code, dev->keybit);
1984                 break;
1985 
1986         case EV_REL:
1987                 __set_bit(code, dev->relbit);
1988                 break;
1989 
1990         case EV_ABS:
1991                 input_alloc_absinfo(dev);
1992                 if (!dev->absinfo)
1993                         return;
1994 
1995                 __set_bit(code, dev->absbit);
1996                 break;
1997 
1998         case EV_MSC:
1999                 __set_bit(code, dev->mscbit);
2000                 break;
2001 
2002         case EV_SW:
2003                 __set_bit(code, dev->swbit);
2004                 break;
2005 
2006         case EV_LED:
2007                 __set_bit(code, dev->ledbit);
2008                 break;
2009 
2010         case EV_SND:
2011                 __set_bit(code, dev->sndbit);
2012                 break;
2013 
2014         case EV_FF:
2015                 __set_bit(code, dev->ffbit);
2016                 break;
2017 
2018         case EV_PWR:
2019                 /* do nothing */
2020                 break;
2021 
2022         default:
2023                 pr_err("%s: unknown type %u (code %u)\n", __func__, type, code);
2024                 dump_stack();
2025                 return;
2026         }
2027 
2028         __set_bit(type, dev->evbit);
2029 }
2030 EXPORT_SYMBOL(input_set_capability);
2031 
2032 static unsigned int input_estimate_events_per_packet(struct input_dev *dev)
2033 {
2034         int mt_slots;
2035         int i;
2036         unsigned int events;
2037 
2038         if (dev->mt) {
2039                 mt_slots = dev->mt->num_slots;
2040         } else if (test_bit(ABS_MT_TRACKING_ID, dev->absbit)) {
2041                 mt_slots = dev->absinfo[ABS_MT_TRACKING_ID].maximum -
2042                            dev->absinfo[ABS_MT_TRACKING_ID].minimum + 1,
2043                 mt_slots = clamp(mt_slots, 2, 32);
2044         } else if (test_bit(ABS_MT_POSITION_X, dev->absbit)) {
2045                 mt_slots = 2;
2046         } else {
2047                 mt_slots = 0;
2048         }
2049 
2050         events = mt_slots + 1; /* count SYN_MT_REPORT and SYN_REPORT */
2051 
2052         if (test_bit(EV_ABS, dev->evbit))
2053                 for_each_set_bit(i, dev->absbit, ABS_CNT)
2054                         events += input_is_mt_axis(i) ? mt_slots : 1;
2055 
2056         if (test_bit(EV_REL, dev->evbit))
2057                 events += bitmap_weight(dev->relbit, REL_CNT);
2058 
2059         /* Make room for KEY and MSC events */
2060         events += 7;
2061 
2062         return events;
2063 }
2064 
2065 #define INPUT_CLEANSE_BITMASK(dev, type, bits)                          \
2066         do {                                                            \
2067                 if (!test_bit(EV_##type, dev->evbit))                   \
2068                         memset(dev->bits##bit, 0,                       \
2069                                 sizeof(dev->bits##bit));                \
2070         } while (0)
2071 
2072 static void input_cleanse_bitmasks(struct input_dev *dev)
2073 {
2074         INPUT_CLEANSE_BITMASK(dev, KEY, key);
2075         INPUT_CLEANSE_BITMASK(dev, REL, rel);
2076         INPUT_CLEANSE_BITMASK(dev, ABS, abs);
2077         INPUT_CLEANSE_BITMASK(dev, MSC, msc);
2078         INPUT_CLEANSE_BITMASK(dev, LED, led);
2079         INPUT_CLEANSE_BITMASK(dev, SND, snd);
2080         INPUT_CLEANSE_BITMASK(dev, FF, ff);
2081         INPUT_CLEANSE_BITMASK(dev, SW, sw);
2082 }
2083 
2084 static void __input_unregister_device(struct input_dev *dev)
2085 {
2086         struct input_handle *handle, *next;
2087 
2088         input_disconnect_device(dev);
2089 
2090         mutex_lock(&input_mutex);
2091 
2092         list_for_each_entry_safe(handle, next, &dev->h_list, d_node)
2093                 handle->handler->disconnect(handle);
2094         WARN_ON(!list_empty(&dev->h_list));
2095 
2096         del_timer_sync(&dev->timer);
2097         list_del_init(&dev->node);
2098 
2099         input_wakeup_procfs_readers();
2100 
2101         mutex_unlock(&input_mutex);
2102 
2103         device_del(&dev->dev);
2104 }
2105 
2106 static void devm_input_device_unregister(struct device *dev, void *res)
2107 {
2108         struct input_devres *devres = res;
2109         struct input_dev *input = devres->input;
2110 
2111         dev_dbg(dev, "%s: unregistering device %s\n",
2112                 __func__, dev_name(&input->dev));
2113         __input_unregister_device(input);
2114 }
2115 
2116 /**
2117  * input_enable_softrepeat - enable software autorepeat
2118  * @dev: input device
2119  * @delay: repeat delay
2120  * @period: repeat period
2121  *
2122  * Enable software autorepeat on the input device.
2123  */
2124 void input_enable_softrepeat(struct input_dev *dev, int delay, int period)
2125 {
2126         dev->timer.function = input_repeat_key;
2127         dev->rep[REP_DELAY] = delay;
2128         dev->rep[REP_PERIOD] = period;
2129 }
2130 EXPORT_SYMBOL(input_enable_softrepeat);
2131 
2132 /**
2133  * input_register_device - register device with input core
2134  * @dev: device to be registered
2135  *
2136  * This function registers device with input core. The device must be
2137  * allocated with input_allocate_device() and all it's capabilities
2138  * set up before registering.
2139  * If function fails the device must be freed with input_free_device().
2140  * Once device has been successfully registered it can be unregistered
2141  * with input_unregister_device(); input_free_device() should not be
2142  * called in this case.
2143  *
2144  * Note that this function is also used to register managed input devices
2145  * (ones allocated with devm_input_allocate_device()). Such managed input
2146  * devices need not be explicitly unregistered or freed, their tear down
2147  * is controlled by the devres infrastructure. It is also worth noting
2148  * that tear down of managed input devices is internally a 2-step process:
2149  * registered managed input device is first unregistered, but stays in
2150  * memory and can still handle input_event() calls (although events will
2151  * not be delivered anywhere). The freeing of managed input device will
2152  * happen later, when devres stack is unwound to the point where device
2153  * allocation was made.
2154  */
2155 int input_register_device(struct input_dev *dev)
2156 {
2157         struct input_devres *devres = NULL;
2158         struct input_handler *handler;
2159         unsigned int packet_size;
2160         const char *path;
2161         int error;
2162 
2163         if (test_bit(EV_ABS, dev->evbit) && !dev->absinfo) {
2164                 dev_err(&dev->dev,
2165                         "Absolute device without dev->absinfo, refusing to register\n");
2166                 return -EINVAL;
2167         }
2168 
2169         if (dev->devres_managed) {
2170                 devres = devres_alloc(devm_input_device_unregister,
2171                                       sizeof(*devres), GFP_KERNEL);
2172                 if (!devres)
2173                         return -ENOMEM;
2174 
2175                 devres->input = dev;
2176         }
2177 
2178         /* Every input device generates EV_SYN/SYN_REPORT events. */
2179         __set_bit(EV_SYN, dev->evbit);
2180 
2181         /* KEY_RESERVED is not supposed to be transmitted to userspace. */
2182         __clear_bit(KEY_RESERVED, dev->keybit);
2183 
2184         /* Make sure that bitmasks not mentioned in dev->evbit are clean. */
2185         input_cleanse_bitmasks(dev);
2186 
2187         packet_size = input_estimate_events_per_packet(dev);
2188         if (dev->hint_events_per_packet < packet_size)
2189                 dev->hint_events_per_packet = packet_size;
2190 
2191         dev->max_vals = dev->hint_events_per_packet + 2;
2192         dev->vals = kcalloc(dev->max_vals, sizeof(*dev->vals), GFP_KERNEL);
2193         if (!dev->vals) {
2194                 error = -ENOMEM;
2195                 goto err_devres_free;
2196         }
2197 
2198         /*
2199          * If delay and period are pre-set by the driver, then autorepeating
2200          * is handled by the driver itself and we don't do it in input.c.
2201          */
2202         if (!dev->rep[REP_DELAY] && !dev->rep[REP_PERIOD])
2203                 input_enable_softrepeat(dev, 250, 33);
2204 
2205         if (!dev->getkeycode)
2206                 dev->getkeycode = input_default_getkeycode;
2207 
2208         if (!dev->setkeycode)
2209                 dev->setkeycode = input_default_setkeycode;
2210 
2211         if (dev->poller)
2212                 input_dev_poller_finalize(dev->poller);
2213 
2214         error = device_add(&dev->dev);
2215         if (error)
2216                 goto err_free_vals;
2217 
2218         path = kobject_get_path(&dev->dev.kobj, GFP_KERNEL);
2219         pr_info("%s as %s\n",
2220                 dev->name ? dev->name : "Unspecified device",
2221                 path ? path : "N/A");
2222         kfree(path);
2223 
2224         error = mutex_lock_interruptible(&input_mutex);
2225         if (error)
2226                 goto err_device_del;
2227 
2228         list_add_tail(&dev->node, &input_dev_list);
2229 
2230         list_for_each_entry(handler, &input_handler_list, node)
2231                 input_attach_handler(dev, handler);
2232 
2233         input_wakeup_procfs_readers();
2234 
2235         mutex_unlock(&input_mutex);
2236 
2237         if (dev->devres_managed) {
2238                 dev_dbg(dev->dev.parent, "%s: registering %s with devres.\n",
2239                         __func__, dev_name(&dev->dev));
2240                 devres_add(dev->dev.parent, devres);
2241         }
2242         return 0;
2243 
2244 err_device_del:
2245         device_del(&dev->dev);
2246 err_free_vals:
2247         kfree(dev->vals);
2248         dev->vals = NULL;
2249 err_devres_free:
2250         devres_free(devres);
2251         return error;
2252 }
2253 EXPORT_SYMBOL(input_register_device);
2254 
2255 /**
2256  * input_unregister_device - unregister previously registered device
2257  * @dev: device to be unregistered
2258  *
2259  * This function unregisters an input device. Once device is unregistered
2260  * the caller should not try to access it as it may get freed at any moment.
2261  */
2262 void input_unregister_device(struct input_dev *dev)
2263 {
2264         if (dev->devres_managed) {
2265                 WARN_ON(devres_destroy(dev->dev.parent,
2266                                         devm_input_device_unregister,
2267                                         devm_input_device_match,
2268                                         dev));
2269                 __input_unregister_device(dev);
2270                 /*
2271                  * We do not do input_put_device() here because it will be done
2272                  * when 2nd devres fires up.
2273                  */
2274         } else {
2275                 __input_unregister_device(dev);
2276                 input_put_device(dev);
2277         }
2278 }
2279 EXPORT_SYMBOL(input_unregister_device);
2280 
2281 /**
2282  * input_register_handler - register a new input handler
2283  * @handler: handler to be registered
2284  *
2285  * This function registers a new input handler (interface) for input
2286  * devices in the system and attaches it to all input devices that
2287  * are compatible with the handler.
2288  */
2289 int input_register_handler(struct input_handler *handler)
2290 {
2291         struct input_dev *dev;
2292         int error;
2293 
2294         error = mutex_lock_interruptible(&input_mutex);
2295         if (error)
2296                 return error;
2297 
2298         INIT_LIST_HEAD(&handler->h_list);
2299 
2300         list_add_tail(&handler->node, &input_handler_list);
2301 
2302         list_for_each_entry(dev, &input_dev_list, node)
2303                 input_attach_handler(dev, handler);
2304 
2305         input_wakeup_procfs_readers();
2306 
2307         mutex_unlock(&input_mutex);
2308         return 0;
2309 }
2310 EXPORT_SYMBOL(input_register_handler);
2311 
2312 /**
2313  * input_unregister_handler - unregisters an input handler
2314  * @handler: handler to be unregistered
2315  *
2316  * This function disconnects a handler from its input devices and
2317  * removes it from lists of known handlers.
2318  */
2319 void input_unregister_handler(struct input_handler *handler)
2320 {
2321         struct input_handle *handle, *next;
2322 
2323         mutex_lock(&input_mutex);
2324 
2325         list_for_each_entry_safe(handle, next, &handler->h_list, h_node)
2326                 handler->disconnect(handle);
2327         WARN_ON(!list_empty(&handler->h_list));
2328 
2329         list_del_init(&handler->node);
2330 
2331         input_wakeup_procfs_readers();
2332 
2333         mutex_unlock(&input_mutex);
2334 }
2335 EXPORT_SYMBOL(input_unregister_handler);
2336 
2337 /**
2338  * input_handler_for_each_handle - handle iterator
2339  * @handler: input handler to iterate
2340  * @data: data for the callback
2341  * @fn: function to be called for each handle
2342  *
2343  * Iterate over @bus's list of devices, and call @fn for each, passing
2344  * it @data and stop when @fn returns a non-zero value. The function is
2345  * using RCU to traverse the list and therefore may be using in atomic
2346  * contexts. The @fn callback is invoked from RCU critical section and
2347  * thus must not sleep.
2348  */
2349 int input_handler_for_each_handle(struct input_handler *handler, void *data,
2350                                   int (*fn)(struct input_handle *, void *))
2351 {
2352         struct input_handle *handle;
2353         int retval = 0;
2354 
2355         rcu_read_lock();
2356 
2357         list_for_each_entry_rcu(handle, &handler->h_list, h_node) {
2358                 retval = fn(handle, data);
2359                 if (retval)
2360                         break;
2361         }
2362 
2363         rcu_read_unlock();
2364 
2365         return retval;
2366 }
2367 EXPORT_SYMBOL(input_handler_for_each_handle);
2368 
2369 /**
2370  * input_register_handle - register a new input handle
2371  * @handle: handle to register
2372  *
2373  * This function puts a new input handle onto device's
2374  * and handler's lists so that events can flow through
2375  * it once it is opened using input_open_device().
2376  *
2377  * This function is supposed to be called from handler's
2378  * connect() method.
2379  */
2380 int input_register_handle(struct input_handle *handle)
2381 {
2382         struct input_handler *handler = handle->handler;
2383         struct input_dev *dev = handle->dev;
2384         int error;
2385 
2386         /*
2387          * We take dev->mutex here to prevent race with
2388          * input_release_device().
2389          */
2390         error = mutex_lock_interruptible(&dev->mutex);
2391         if (error)
2392                 return error;
2393 
2394         /*
2395          * Filters go to the head of the list, normal handlers
2396          * to the tail.
2397          */
2398         if (handler->filter)
2399                 list_add_rcu(&handle->d_node, &dev->h_list);
2400         else
2401                 list_add_tail_rcu(&handle->d_node, &dev->h_list);
2402 
2403         mutex_unlock(&dev->mutex);
2404 
2405         /*
2406          * Since we are supposed to be called from ->connect()
2407          * which is mutually exclusive with ->disconnect()
2408          * we can't be racing with input_unregister_handle()
2409          * and so separate lock is not needed here.
2410          */
2411         list_add_tail_rcu(&handle->h_node, &handler->h_list);
2412 
2413         if (handler->start)
2414                 handler->start(handle);
2415 
2416         return 0;
2417 }
2418 EXPORT_SYMBOL(input_register_handle);
2419 
2420 /**
2421  * input_unregister_handle - unregister an input handle
2422  * @handle: handle to unregister
2423  *
2424  * This function removes input handle from device's
2425  * and handler's lists.
2426  *
2427  * This function is supposed to be called from handler's
2428  * disconnect() method.
2429  */
2430 void input_unregister_handle(struct input_handle *handle)
2431 {
2432         struct input_dev *dev = handle->dev;
2433 
2434         list_del_rcu(&handle->h_node);
2435 
2436         /*
2437          * Take dev->mutex to prevent race with input_release_device().
2438          */
2439         mutex_lock(&dev->mutex);
2440         list_del_rcu(&handle->d_node);
2441         mutex_unlock(&dev->mutex);
2442 
2443         synchronize_rcu();
2444 }
2445 EXPORT_SYMBOL(input_unregister_handle);
2446 
2447 /**
2448  * input_get_new_minor - allocates a new input minor number
2449  * @legacy_base: beginning or the legacy range to be searched
2450  * @legacy_num: size of legacy range
2451  * @allow_dynamic: whether we can also take ID from the dynamic range
2452  *
2453  * This function allocates a new device minor for from input major namespace.
2454  * Caller can request legacy minor by specifying @legacy_base and @legacy_num
2455  * parameters and whether ID can be allocated from dynamic range if there are
2456  * no free IDs in legacy range.
2457  */
2458 int input_get_new_minor(int legacy_base, unsigned int legacy_num,
2459                         bool allow_dynamic)
2460 {
2461         /*
2462          * This function should be called from input handler's ->connect()
2463          * methods, which are serialized with input_mutex, so no additional
2464          * locking is needed here.
2465          */
2466         if (legacy_base >= 0) {
2467                 int minor = ida_simple_get(&input_ida,
2468                                            legacy_base,
2469                                            legacy_base + legacy_num,
2470                                            GFP_KERNEL);
2471                 if (minor >= 0 || !allow_dynamic)
2472                         return minor;
2473         }
2474 
2475         return ida_simple_get(&input_ida,
2476                               INPUT_FIRST_DYNAMIC_DEV, INPUT_MAX_CHAR_DEVICES,
2477                               GFP_KERNEL);
2478 }
2479 EXPORT_SYMBOL(input_get_new_minor);
2480 
2481 /**
2482  * input_free_minor - release previously allocated minor
2483  * @minor: minor to be released
2484  *
2485  * This function releases previously allocated input minor so that it can be
2486  * reused later.
2487  */
2488 void input_free_minor(unsigned int minor)
2489 {
2490         ida_simple_remove(&input_ida, minor);
2491 }
2492 EXPORT_SYMBOL(input_free_minor);
2493 
2494 static int __init input_init(void)
2495 {
2496         int err;
2497 
2498         err = class_register(&input_class);
2499         if (err) {
2500                 pr_err("unable to register input_dev class\n");
2501                 return err;
2502         }
2503 
2504         err = input_proc_init();
2505         if (err)
2506                 goto fail1;
2507 
2508         err = register_chrdev_region(MKDEV(INPUT_MAJOR, 0),
2509                                      INPUT_MAX_CHAR_DEVICES, "input");
2510         if (err) {
2511                 pr_err("unable to register char major %d", INPUT_MAJOR);
2512                 goto fail2;
2513         }
2514 
2515         return 0;
2516 
2517  fail2: input_proc_exit();
2518  fail1: class_unregister(&input_class);
2519         return err;
2520 }
2521 
2522 static void __exit input_exit(void)
2523 {
2524         input_proc_exit();
2525         unregister_chrdev_region(MKDEV(INPUT_MAJOR, 0),
2526                                  INPUT_MAX_CHAR_DEVICES);
2527         class_unregister(&input_class);
2528 }
2529 
2530 subsys_initcall(input_init);
2531 module_exit(input_exit);
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/input/input.c

DEFINITIONS
