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/kstrtox.h>
  25#include <linux/mutex.h>
  26#include <linux/rcupdate.h>
  27#include "input-compat.h"
  28#include "input-core-private.h"
  29#include "input-poller.h"
  30
  31MODULE_AUTHOR("Vojtech Pavlik <vojtech@suse.cz>");
  32MODULE_DESCRIPTION("Input core");
  33MODULE_LICENSE("GPL");
  34
  35#define INPUT_MAX_CHAR_DEVICES		1024
  36#define INPUT_FIRST_DYNAMIC_DEV		256
  37static DEFINE_IDA(input_ida);
  38
  39static LIST_HEAD(input_dev_list);
  40static LIST_HEAD(input_handler_list);
  41
  42/*
  43 * input_mutex protects access to both input_dev_list and input_handler_list.
  44 * This also causes input_[un]register_device and input_[un]register_handler
  45 * be mutually exclusive which simplifies locking in drivers implementing
  46 * input handlers.
  47 */
  48static DEFINE_MUTEX(input_mutex);
  49
  50static const struct input_value input_value_sync = { EV_SYN, SYN_REPORT, 1 };
  51
  52static const unsigned int input_max_code[EV_CNT] = {
  53	[EV_KEY] = KEY_MAX,
  54	[EV_REL] = REL_MAX,
  55	[EV_ABS] = ABS_MAX,
  56	[EV_MSC] = MSC_MAX,
  57	[EV_SW] = SW_MAX,
  58	[EV_LED] = LED_MAX,
  59	[EV_SND] = SND_MAX,
  60	[EV_FF] = FF_MAX,
  61};
  62
  63static inline int is_event_supported(unsigned int code,
  64				     unsigned long *bm, unsigned int max)
  65{
  66	return code <= max && test_bit(code, bm);
  67}
  68
  69static int input_defuzz_abs_event(int value, int old_val, int fuzz)
  70{
  71	if (fuzz) {
  72		if (value > old_val - fuzz / 2 && value < old_val + fuzz / 2)
  73			return old_val;
  74
  75		if (value > old_val - fuzz && value < old_val + fuzz)
  76			return (old_val * 3 + value) / 4;
  77
  78		if (value > old_val - fuzz * 2 && value < old_val + fuzz * 2)
  79			return (old_val + value) / 2;
  80	}
  81
  82	return value;
  83}
  84
  85static void input_start_autorepeat(struct input_dev *dev, int code)
  86{
  87	if (test_bit(EV_REP, dev->evbit) &&
  88	    dev->rep[REP_PERIOD] && dev->rep[REP_DELAY] &&
  89	    dev->timer.function) {
  90		dev->repeat_key = code;
  91		mod_timer(&dev->timer,
  92			  jiffies + msecs_to_jiffies(dev->rep[REP_DELAY]));
  93	}
  94}
  95
  96static void input_stop_autorepeat(struct input_dev *dev)
  97{
  98	del_timer(&dev->timer);
  99}
 100
 101/*
 102 * Pass event first through all filters and then, if event has not been
 103 * filtered out, through all open handles. This function is called with
 104 * dev->event_lock held and interrupts disabled.
 105 */
 106static unsigned int input_to_handler(struct input_handle *handle,
 107			struct input_value *vals, unsigned int count)
 108{
 109	struct input_handler *handler = handle->handler;
 110	struct input_value *end = vals;
 111	struct input_value *v;
 112
 113	if (handler->filter) {
 114		for (v = vals; v != vals + count; v++) {
 115			if (handler->filter(handle, v->type, v->code, v->value))
 116				continue;
 117			if (end != v)
 118				*end = *v;
 119			end++;
 120		}
 121		count = end - vals;
 122	}
 123
 124	if (!count)
 125		return 0;
 126
 127	if (handler->events)
 128		handler->events(handle, vals, count);
 129	else if (handler->event)
 130		for (v = vals; v != vals + count; v++)
 131			handler->event(handle, v->type, v->code, v->value);
 132
 133	return count;
 134}
 135
 136/*
 137 * Pass values first through all filters and then, if event has not been
 138 * filtered out, through all open handles. This function is called with
 139 * dev->event_lock held and interrupts disabled.
 140 */
 141static void input_pass_values(struct input_dev *dev,
 142			      struct input_value *vals, unsigned int count)
 143{
 144	struct input_handle *handle;
 145	struct input_value *v;
 146
 147	lockdep_assert_held(&dev->event_lock);
 148
 149	if (!count)
 150		return;
 151
 152	rcu_read_lock();
 153
 154	handle = rcu_dereference(dev->grab);
 155	if (handle) {
 156		count = input_to_handler(handle, vals, count);
 157	} else {
 158		list_for_each_entry_rcu(handle, &dev->h_list, d_node)
 159			if (handle->open) {
 160				count = input_to_handler(handle, vals, count);
 161				if (!count)
 162					break;
 163			}
 164	}
 165
 166	rcu_read_unlock();
 167
 168	/* trigger auto repeat for key events */
 169	if (test_bit(EV_REP, dev->evbit) && test_bit(EV_KEY, dev->evbit)) {
 170		for (v = vals; v != vals + count; v++) {
 171			if (v->type == EV_KEY && v->value != 2) {
 172				if (v->value)
 173					input_start_autorepeat(dev, v->code);
 174				else
 175					input_stop_autorepeat(dev);
 176			}
 177		}
 178	}
 179}
 180
 181#define INPUT_IGNORE_EVENT	0
 182#define INPUT_PASS_TO_HANDLERS	1
 183#define INPUT_PASS_TO_DEVICE	2
 184#define INPUT_SLOT		4
 185#define INPUT_FLUSH		8
 186#define INPUT_PASS_TO_ALL	(INPUT_PASS_TO_HANDLERS | INPUT_PASS_TO_DEVICE)
 187
 188static int input_handle_abs_event(struct input_dev *dev,
 189				  unsigned int code, int *pval)
 190{
 191	struct input_mt *mt = dev->mt;
 
 192	bool is_mt_event;
 193	int *pold;
 194
 195	if (code == ABS_MT_SLOT) {
 196		/*
 197		 * "Stage" the event; we'll flush it later, when we
 198		 * get actual touch data.
 199		 */
 200		if (mt && *pval >= 0 && *pval < mt->num_slots)
 201			mt->slot = *pval;
 202
 203		return INPUT_IGNORE_EVENT;
 204	}
 205
 206	is_mt_event = input_is_mt_value(code);
 207
 208	if (!is_mt_event) {
 209		pold = &dev->absinfo[code].value;
 210	} else if (mt) {
 211		pold = &mt->slots[mt->slot].abs[code - ABS_MT_FIRST];
 
 212	} else {
 213		/*
 214		 * Bypass filtering for multi-touch events when
 215		 * not employing slots.
 216		 */
 217		pold = NULL;
 218	}
 219
 220	if (pold) {
 221		*pval = input_defuzz_abs_event(*pval, *pold,
 222						dev->absinfo[code].fuzz);
 223		if (*pold == *pval)
 224			return INPUT_IGNORE_EVENT;
 225
 226		*pold = *pval;
 227	}
 228
 229	/* Flush pending "slot" event */
 230	if (is_mt_event && mt && mt->slot != input_abs_get_val(dev, ABS_MT_SLOT)) {
 231		input_abs_set_val(dev, ABS_MT_SLOT, mt->slot);
 232		return INPUT_PASS_TO_HANDLERS | INPUT_SLOT;
 233	}
 234
 235	return INPUT_PASS_TO_HANDLERS;
 236}
 237
 238static int input_get_disposition(struct input_dev *dev,
 239			  unsigned int type, unsigned int code, int *pval)
 240{
 241	int disposition = INPUT_IGNORE_EVENT;
 242	int value = *pval;
 243
 244	/* filter-out events from inhibited devices */
 245	if (dev->inhibited)
 246		return INPUT_IGNORE_EVENT;
 247
 248	switch (type) {
 249
 250	case EV_SYN:
 251		switch (code) {
 252		case SYN_CONFIG:
 253			disposition = INPUT_PASS_TO_ALL;
 254			break;
 255
 256		case SYN_REPORT:
 257			disposition = INPUT_PASS_TO_HANDLERS | INPUT_FLUSH;
 258			break;
 259		case SYN_MT_REPORT:
 260			disposition = INPUT_PASS_TO_HANDLERS;
 261			break;
 262		}
 263		break;
 264
 265	case EV_KEY:
 266		if (is_event_supported(code, dev->keybit, KEY_MAX)) {
 267
 268			/* auto-repeat bypasses state updates */
 269			if (value == 2) {
 270				disposition = INPUT_PASS_TO_HANDLERS;
 271				break;
 272			}
 273
 274			if (!!test_bit(code, dev->key) != !!value) {
 275
 276				__change_bit(code, dev->key);
 277				disposition = INPUT_PASS_TO_HANDLERS;
 278			}
 279		}
 280		break;
 281
 282	case EV_SW:
 283		if (is_event_supported(code, dev->swbit, SW_MAX) &&
 284		    !!test_bit(code, dev->sw) != !!value) {
 285
 286			__change_bit(code, dev->sw);
 287			disposition = INPUT_PASS_TO_HANDLERS;
 288		}
 289		break;
 290
 291	case EV_ABS:
 292		if (is_event_supported(code, dev->absbit, ABS_MAX))
 293			disposition = input_handle_abs_event(dev, code, &value);
 294
 295		break;
 296
 297	case EV_REL:
 298		if (is_event_supported(code, dev->relbit, REL_MAX) && value)
 299			disposition = INPUT_PASS_TO_HANDLERS;
 300
 301		break;
 302
 303	case EV_MSC:
 304		if (is_event_supported(code, dev->mscbit, MSC_MAX))
 305			disposition = INPUT_PASS_TO_ALL;
 306
 307		break;
 308
 309	case EV_LED:
 310		if (is_event_supported(code, dev->ledbit, LED_MAX) &&
 311		    !!test_bit(code, dev->led) != !!value) {
 312
 313			__change_bit(code, dev->led);
 314			disposition = INPUT_PASS_TO_ALL;
 315		}
 316		break;
 317
 318	case EV_SND:
 319		if (is_event_supported(code, dev->sndbit, SND_MAX)) {
 320
 321			if (!!test_bit(code, dev->snd) != !!value)
 322				__change_bit(code, dev->snd);
 323			disposition = INPUT_PASS_TO_ALL;
 324		}
 325		break;
 326
 327	case EV_REP:
 328		if (code <= REP_MAX && value >= 0 && dev->rep[code] != value) {
 329			dev->rep[code] = value;
 330			disposition = INPUT_PASS_TO_ALL;
 331		}
 332		break;
 333
 334	case EV_FF:
 335		if (value >= 0)
 336			disposition = INPUT_PASS_TO_ALL;
 337		break;
 338
 339	case EV_PWR:
 340		disposition = INPUT_PASS_TO_ALL;
 341		break;
 342	}
 343
 344	*pval = value;
 345	return disposition;
 346}
 347
 348static void input_event_dispose(struct input_dev *dev, int disposition,
 349				unsigned int type, unsigned int code, int value)
 350{
 351	if ((disposition & INPUT_PASS_TO_DEVICE) && dev->event)
 352		dev->event(dev, type, code, value);
 353
 354	if (!dev->vals)
 355		return;
 356
 357	if (disposition & INPUT_PASS_TO_HANDLERS) {
 358		struct input_value *v;
 359
 360		if (disposition & INPUT_SLOT) {
 361			v = &dev->vals[dev->num_vals++];
 362			v->type = EV_ABS;
 363			v->code = ABS_MT_SLOT;
 364			v->value = dev->mt->slot;
 365		}
 366
 367		v = &dev->vals[dev->num_vals++];
 368		v->type = type;
 369		v->code = code;
 370		v->value = value;
 371	}
 372
 373	if (disposition & INPUT_FLUSH) {
 374		if (dev->num_vals >= 2)
 375			input_pass_values(dev, dev->vals, dev->num_vals);
 376		dev->num_vals = 0;
 377		/*
 378		 * Reset the timestamp on flush so we won't end up
 379		 * with a stale one. Note we only need to reset the
 380		 * monolithic one as we use its presence when deciding
 381		 * whether to generate a synthetic timestamp.
 382		 */
 383		dev->timestamp[INPUT_CLK_MONO] = ktime_set(0, 0);
 384	} else if (dev->num_vals >= dev->max_vals - 2) {
 385		dev->vals[dev->num_vals++] = input_value_sync;
 386		input_pass_values(dev, dev->vals, dev->num_vals);
 387		dev->num_vals = 0;
 388	}
 389}
 390
 391void input_handle_event(struct input_dev *dev,
 392			unsigned int type, unsigned int code, int value)
 393{
 394	int disposition;
 395
 396	lockdep_assert_held(&dev->event_lock);
 397
 398	disposition = input_get_disposition(dev, type, code, &value);
 399	if (disposition != INPUT_IGNORE_EVENT) {
 400		if (type != EV_SYN)
 401			add_input_randomness(type, code, value);
 402
 403		input_event_dispose(dev, disposition, type, code, value);
 404	}
 405}
 406
 407/**
 408 * input_event() - report new input event
 409 * @dev: device that generated the event
 410 * @type: type of the event
 411 * @code: event code
 412 * @value: value of the event
 413 *
 414 * This function should be used by drivers implementing various input
 415 * devices to report input events. See also input_inject_event().
 416 *
 417 * NOTE: input_event() may be safely used right after input device was
 418 * allocated with input_allocate_device(), even before it is registered
 419 * with input_register_device(), but the event will not reach any of the
 420 * input handlers. Such early invocation of input_event() may be used
 421 * to 'seed' initial state of a switch or initial position of absolute
 422 * axis, etc.
 423 */
 424void input_event(struct input_dev *dev,
 425		 unsigned int type, unsigned int code, int value)
 426{
 427	unsigned long flags;
 428
 429	if (is_event_supported(type, dev->evbit, EV_MAX)) {
 430
 431		spin_lock_irqsave(&dev->event_lock, flags);
 432		input_handle_event(dev, type, code, value);
 433		spin_unlock_irqrestore(&dev->event_lock, flags);
 434	}
 435}
 436EXPORT_SYMBOL(input_event);
 437
 438/**
 439 * input_inject_event() - send input event from input handler
 440 * @handle: input handle to send event through
 441 * @type: type of the event
 442 * @code: event code
 443 * @value: value of the event
 444 *
 445 * Similar to input_event() but will ignore event if device is
 446 * "grabbed" and handle injecting event is not the one that owns
 447 * the device.
 448 */
 449void input_inject_event(struct input_handle *handle,
 450			unsigned int type, unsigned int code, int value)
 451{
 452	struct input_dev *dev = handle->dev;
 453	struct input_handle *grab;
 454	unsigned long flags;
 455
 456	if (is_event_supported(type, dev->evbit, EV_MAX)) {
 457		spin_lock_irqsave(&dev->event_lock, flags);
 458
 459		rcu_read_lock();
 460		grab = rcu_dereference(dev->grab);
 461		if (!grab || grab == handle)
 462			input_handle_event(dev, type, code, value);
 463		rcu_read_unlock();
 464
 465		spin_unlock_irqrestore(&dev->event_lock, flags);
 466	}
 467}
 468EXPORT_SYMBOL(input_inject_event);
 469
 470/**
 471 * input_alloc_absinfo - allocates array of input_absinfo structs
 472 * @dev: the input device emitting absolute events
 473 *
 474 * If the absinfo struct the caller asked for is already allocated, this
 475 * functions will not do anything.
 476 */
 477void input_alloc_absinfo(struct input_dev *dev)
 478{
 479	if (dev->absinfo)
 480		return;
 481
 482	dev->absinfo = kcalloc(ABS_CNT, sizeof(*dev->absinfo), GFP_KERNEL);
 483	if (!dev->absinfo) {
 484		dev_err(dev->dev.parent ?: &dev->dev,
 485			"%s: unable to allocate memory\n", __func__);
 486		/*
 487		 * We will handle this allocation failure in
 488		 * input_register_device() when we refuse to register input
 489		 * device with ABS bits but without absinfo.
 490		 */
 491	}
 492}
 493EXPORT_SYMBOL(input_alloc_absinfo);
 494
 495void input_set_abs_params(struct input_dev *dev, unsigned int axis,
 496			  int min, int max, int fuzz, int flat)
 497{
 498	struct input_absinfo *absinfo;
 499
 500	__set_bit(EV_ABS, dev->evbit);
 501	__set_bit(axis, dev->absbit);
 502
 503	input_alloc_absinfo(dev);
 504	if (!dev->absinfo)
 505		return;
 506
 507	absinfo = &dev->absinfo[axis];
 508	absinfo->minimum = min;
 509	absinfo->maximum = max;
 510	absinfo->fuzz = fuzz;
 511	absinfo->flat = flat;
 512}
 513EXPORT_SYMBOL(input_set_abs_params);
 514
 515/**
 516 * input_copy_abs - Copy absinfo from one input_dev to another
 517 * @dst: Destination input device to copy the abs settings to
 518 * @dst_axis: ABS_* value selecting the destination axis
 519 * @src: Source input device to copy the abs settings from
 520 * @src_axis: ABS_* value selecting the source axis
 521 *
 522 * Set absinfo for the selected destination axis by copying it from
 523 * the specified source input device's source axis.
 524 * This is useful to e.g. setup a pen/stylus input-device for combined
 525 * touchscreen/pen hardware where the pen uses the same coordinates as
 526 * the touchscreen.
 527 */
 528void input_copy_abs(struct input_dev *dst, unsigned int dst_axis,
 529		    const struct input_dev *src, unsigned int src_axis)
 530{
 531	/* src must have EV_ABS and src_axis set */
 532	if (WARN_ON(!(test_bit(EV_ABS, src->evbit) &&
 533		      test_bit(src_axis, src->absbit))))
 534		return;
 535
 536	/*
 537	 * input_alloc_absinfo() may have failed for the source. Our caller is
 538	 * expected to catch this when registering the input devices, which may
 539	 * happen after the input_copy_abs() call.
 540	 */
 541	if (!src->absinfo)
 542		return;
 543
 544	input_set_capability(dst, EV_ABS, dst_axis);
 545	if (!dst->absinfo)
 546		return;
 547
 548	dst->absinfo[dst_axis] = src->absinfo[src_axis];
 549}
 550EXPORT_SYMBOL(input_copy_abs);
 551
 552/**
 553 * input_grab_device - grabs device for exclusive use
 554 * @handle: input handle that wants to own the device
 555 *
 556 * When a device is grabbed by an input handle all events generated by
 557 * the device are delivered only to this handle. Also events injected
 558 * by other input handles are ignored while device is grabbed.
 559 */
 560int input_grab_device(struct input_handle *handle)
 561{
 562	struct input_dev *dev = handle->dev;
 563	int retval;
 564
 565	retval = mutex_lock_interruptible(&dev->mutex);
 566	if (retval)
 567		return retval;
 568
 569	if (dev->grab) {
 570		retval = -EBUSY;
 571		goto out;
 572	}
 573
 574	rcu_assign_pointer(dev->grab, handle);
 575
 576 out:
 577	mutex_unlock(&dev->mutex);
 578	return retval;
 579}
 580EXPORT_SYMBOL(input_grab_device);
 581
 582static void __input_release_device(struct input_handle *handle)
 583{
 584	struct input_dev *dev = handle->dev;
 585	struct input_handle *grabber;
 586
 587	grabber = rcu_dereference_protected(dev->grab,
 588					    lockdep_is_held(&dev->mutex));
 589	if (grabber == handle) {
 590		rcu_assign_pointer(dev->grab, NULL);
 591		/* Make sure input_pass_values() notices that grab is gone */
 592		synchronize_rcu();
 593
 594		list_for_each_entry(handle, &dev->h_list, d_node)
 595			if (handle->open && handle->handler->start)
 596				handle->handler->start(handle);
 597	}
 598}
 599
 600/**
 601 * input_release_device - release previously grabbed device
 602 * @handle: input handle that owns the device
 603 *
 604 * Releases previously grabbed device so that other input handles can
 605 * start receiving input events. Upon release all handlers attached
 606 * to the device have their start() method called so they have a change
 607 * to synchronize device state with the rest of the system.
 608 */
 609void input_release_device(struct input_handle *handle)
 610{
 611	struct input_dev *dev = handle->dev;
 612
 613	mutex_lock(&dev->mutex);
 614	__input_release_device(handle);
 615	mutex_unlock(&dev->mutex);
 616}
 617EXPORT_SYMBOL(input_release_device);
 618
 619/**
 620 * input_open_device - open input device
 621 * @handle: handle through which device is being accessed
 622 *
 623 * This function should be called by input handlers when they
 624 * want to start receive events from given input device.
 625 */
 626int input_open_device(struct input_handle *handle)
 627{
 628	struct input_dev *dev = handle->dev;
 629	int retval;
 630
 631	retval = mutex_lock_interruptible(&dev->mutex);
 632	if (retval)
 633		return retval;
 634
 635	if (dev->going_away) {
 636		retval = -ENODEV;
 637		goto out;
 638	}
 639
 640	handle->open++;
 641
 642	if (dev->users++ || dev->inhibited) {
 643		/*
 644		 * Device is already opened and/or inhibited,
 645		 * so we can exit immediately and report success.
 646		 */
 647		goto out;
 648	}
 649
 650	if (dev->open) {
 651		retval = dev->open(dev);
 652		if (retval) {
 653			dev->users--;
 654			handle->open--;
 655			/*
 656			 * Make sure we are not delivering any more events
 657			 * through this handle
 658			 */
 659			synchronize_rcu();
 660			goto out;
 661		}
 662	}
 663
 664	if (dev->poller)
 665		input_dev_poller_start(dev->poller);
 666
 667 out:
 668	mutex_unlock(&dev->mutex);
 669	return retval;
 670}
 671EXPORT_SYMBOL(input_open_device);
 672
 673int input_flush_device(struct input_handle *handle, struct file *file)
 674{
 675	struct input_dev *dev = handle->dev;
 676	int retval;
 677
 678	retval = mutex_lock_interruptible(&dev->mutex);
 679	if (retval)
 680		return retval;
 681
 682	if (dev->flush)
 683		retval = dev->flush(dev, file);
 684
 685	mutex_unlock(&dev->mutex);
 686	return retval;
 687}
 688EXPORT_SYMBOL(input_flush_device);
 689
 690/**
 691 * input_close_device - close input device
 692 * @handle: handle through which device is being accessed
 693 *
 694 * This function should be called by input handlers when they
 695 * want to stop receive events from given input device.
 696 */
 697void input_close_device(struct input_handle *handle)
 698{
 699	struct input_dev *dev = handle->dev;
 700
 701	mutex_lock(&dev->mutex);
 702
 703	__input_release_device(handle);
 704
 705	if (!dev->inhibited && !--dev->users) {
 706		if (dev->poller)
 707			input_dev_poller_stop(dev->poller);
 708		if (dev->close)
 709			dev->close(dev);
 710	}
 711
 712	if (!--handle->open) {
 713		/*
 714		 * synchronize_rcu() makes sure that input_pass_values()
 715		 * completed and that no more input events are delivered
 716		 * through this handle
 717		 */
 718		synchronize_rcu();
 719	}
 720
 721	mutex_unlock(&dev->mutex);
 722}
 723EXPORT_SYMBOL(input_close_device);
 724
 725/*
 726 * Simulate keyup events for all keys that are marked as pressed.
 727 * The function must be called with dev->event_lock held.
 728 */
 729static bool input_dev_release_keys(struct input_dev *dev)
 730{
 731	bool need_sync = false;
 732	int code;
 733
 734	lockdep_assert_held(&dev->event_lock);
 735
 736	if (is_event_supported(EV_KEY, dev->evbit, EV_MAX)) {
 737		for_each_set_bit(code, dev->key, KEY_CNT) {
 738			input_handle_event(dev, EV_KEY, code, 0);
 739			need_sync = true;
 740		}
 741	}
 742
 743	return need_sync;
 744}
 745
 746/*
 747 * Prepare device for unregistering
 748 */
 749static void input_disconnect_device(struct input_dev *dev)
 750{
 751	struct input_handle *handle;
 752
 753	/*
 754	 * Mark device as going away. Note that we take dev->mutex here
 755	 * not to protect access to dev->going_away but rather to ensure
 756	 * that there are no threads in the middle of input_open_device()
 757	 */
 758	mutex_lock(&dev->mutex);
 759	dev->going_away = true;
 760	mutex_unlock(&dev->mutex);
 761
 762	spin_lock_irq(&dev->event_lock);
 763
 764	/*
 765	 * Simulate keyup events for all pressed keys so that handlers
 766	 * are not left with "stuck" keys. The driver may continue
 767	 * generate events even after we done here but they will not
 768	 * reach any handlers.
 769	 */
 770	if (input_dev_release_keys(dev))
 771		input_handle_event(dev, EV_SYN, SYN_REPORT, 1);
 772
 773	list_for_each_entry(handle, &dev->h_list, d_node)
 774		handle->open = 0;
 775
 776	spin_unlock_irq(&dev->event_lock);
 777}
 778
 779/**
 780 * input_scancode_to_scalar() - converts scancode in &struct input_keymap_entry
 781 * @ke: keymap entry containing scancode to be converted.
 782 * @scancode: pointer to the location where converted scancode should
 783 *	be stored.
 784 *
 785 * This function is used to convert scancode stored in &struct keymap_entry
 786 * into scalar form understood by legacy keymap handling methods. These
 787 * methods expect scancodes to be represented as 'unsigned int'.
 788 */
 789int input_scancode_to_scalar(const struct input_keymap_entry *ke,
 790			     unsigned int *scancode)
 791{
 792	switch (ke->len) {
 793	case 1:
 794		*scancode = *((u8 *)ke->scancode);
 795		break;
 796
 797	case 2:
 798		*scancode = *((u16 *)ke->scancode);
 799		break;
 800
 801	case 4:
 802		*scancode = *((u32 *)ke->scancode);
 803		break;
 804
 805	default:
 806		return -EINVAL;
 807	}
 808
 809	return 0;
 810}
 811EXPORT_SYMBOL(input_scancode_to_scalar);
 812
 813/*
 814 * Those routines handle the default case where no [gs]etkeycode() is
 815 * defined. In this case, an array indexed by the scancode is used.
 816 */
 817
 818static unsigned int input_fetch_keycode(struct input_dev *dev,
 819					unsigned int index)
 820{
 821	switch (dev->keycodesize) {
 822	case 1:
 823		return ((u8 *)dev->keycode)[index];
 824
 825	case 2:
 826		return ((u16 *)dev->keycode)[index];
 827
 828	default:
 829		return ((u32 *)dev->keycode)[index];
 830	}
 831}
 832
 833static int input_default_getkeycode(struct input_dev *dev,
 834				    struct input_keymap_entry *ke)
 835{
 836	unsigned int index;
 837	int error;
 838
 839	if (!dev->keycodesize)
 840		return -EINVAL;
 841
 842	if (ke->flags & INPUT_KEYMAP_BY_INDEX)
 843		index = ke->index;
 844	else {
 845		error = input_scancode_to_scalar(ke, &index);
 846		if (error)
 847			return error;
 848	}
 849
 850	if (index >= dev->keycodemax)
 851		return -EINVAL;
 852
 853	ke->keycode = input_fetch_keycode(dev, index);
 854	ke->index = index;
 855	ke->len = sizeof(index);
 856	memcpy(ke->scancode, &index, sizeof(index));
 857
 858	return 0;
 859}
 860
 861static int input_default_setkeycode(struct input_dev *dev,
 862				    const struct input_keymap_entry *ke,
 863				    unsigned int *old_keycode)
 864{
 865	unsigned int index;
 866	int error;
 867	int i;
 868
 869	if (!dev->keycodesize)
 870		return -EINVAL;
 871
 872	if (ke->flags & INPUT_KEYMAP_BY_INDEX) {
 873		index = ke->index;
 874	} else {
 875		error = input_scancode_to_scalar(ke, &index);
 876		if (error)
 877			return error;
 878	}
 879
 880	if (index >= dev->keycodemax)
 881		return -EINVAL;
 882
 883	if (dev->keycodesize < sizeof(ke->keycode) &&
 884			(ke->keycode >> (dev->keycodesize * 8)))
 885		return -EINVAL;
 886
 887	switch (dev->keycodesize) {
 888		case 1: {
 889			u8 *k = (u8 *)dev->keycode;
 890			*old_keycode = k[index];
 891			k[index] = ke->keycode;
 892			break;
 893		}
 894		case 2: {
 895			u16 *k = (u16 *)dev->keycode;
 896			*old_keycode = k[index];
 897			k[index] = ke->keycode;
 898			break;
 899		}
 900		default: {
 901			u32 *k = (u32 *)dev->keycode;
 902			*old_keycode = k[index];
 903			k[index] = ke->keycode;
 904			break;
 905		}
 906	}
 907
 908	if (*old_keycode <= KEY_MAX) {
 909		__clear_bit(*old_keycode, dev->keybit);
 910		for (i = 0; i < dev->keycodemax; i++) {
 911			if (input_fetch_keycode(dev, i) == *old_keycode) {
 912				__set_bit(*old_keycode, dev->keybit);
 913				/* Setting the bit twice is useless, so break */
 914				break;
 915			}
 916		}
 917	}
 918
 919	__set_bit(ke->keycode, dev->keybit);
 920	return 0;
 921}
 922
 923/**
 924 * input_get_keycode - retrieve keycode currently mapped to a given scancode
 925 * @dev: input device which keymap is being queried
 926 * @ke: keymap entry
 927 *
 928 * This function should be called by anyone interested in retrieving current
 929 * keymap. Presently evdev handlers use it.
 930 */
 931int input_get_keycode(struct input_dev *dev, struct input_keymap_entry *ke)
 932{
 933	unsigned long flags;
 934	int retval;
 935
 936	spin_lock_irqsave(&dev->event_lock, flags);
 937	retval = dev->getkeycode(dev, ke);
 938	spin_unlock_irqrestore(&dev->event_lock, flags);
 939
 940	return retval;
 941}
 942EXPORT_SYMBOL(input_get_keycode);
 943
 944/**
 945 * input_set_keycode - attribute a keycode to a given scancode
 946 * @dev: input device which keymap is being updated
 947 * @ke: new keymap entry
 948 *
 949 * This function should be called by anyone needing to update current
 950 * keymap. Presently keyboard and evdev handlers use it.
 951 */
 952int input_set_keycode(struct input_dev *dev,
 953		      const struct input_keymap_entry *ke)
 954{
 955	unsigned long flags;
 956	unsigned int old_keycode;
 957	int retval;
 958
 959	if (ke->keycode > KEY_MAX)
 960		return -EINVAL;
 961
 962	spin_lock_irqsave(&dev->event_lock, flags);
 963
 964	retval = dev->setkeycode(dev, ke, &old_keycode);
 965	if (retval)
 966		goto out;
 967
 968	/* Make sure KEY_RESERVED did not get enabled. */
 969	__clear_bit(KEY_RESERVED, dev->keybit);
 970
 971	/*
 972	 * Simulate keyup event if keycode is not present
 973	 * in the keymap anymore
 974	 */
 975	if (old_keycode > KEY_MAX) {
 976		dev_warn(dev->dev.parent ?: &dev->dev,
 977			 "%s: got too big old keycode %#x\n",
 978			 __func__, old_keycode);
 979	} else if (test_bit(EV_KEY, dev->evbit) &&
 980		   !is_event_supported(old_keycode, dev->keybit, KEY_MAX) &&
 981		   __test_and_clear_bit(old_keycode, dev->key)) {
 982		/*
 983		 * We have to use input_event_dispose() here directly instead
 984		 * of input_handle_event() because the key we want to release
 985		 * here is considered no longer supported by the device and
 986		 * input_handle_event() will ignore it.
 987		 */
 988		input_event_dispose(dev, INPUT_PASS_TO_HANDLERS,
 989				    EV_KEY, old_keycode, 0);
 990		input_event_dispose(dev, INPUT_PASS_TO_HANDLERS | INPUT_FLUSH,
 991				    EV_SYN, SYN_REPORT, 1);
 992	}
 993
 994 out:
 995	spin_unlock_irqrestore(&dev->event_lock, flags);
 996
 997	return retval;
 998}
 999EXPORT_SYMBOL(input_set_keycode);
1000
1001bool input_match_device_id(const struct input_dev *dev,
1002			   const struct input_device_id *id)
1003{
1004	if (id->flags & INPUT_DEVICE_ID_MATCH_BUS)
1005		if (id->bustype != dev->id.bustype)
1006			return false;
1007
1008	if (id->flags & INPUT_DEVICE_ID_MATCH_VENDOR)
1009		if (id->vendor != dev->id.vendor)
1010			return false;
1011
1012	if (id->flags & INPUT_DEVICE_ID_MATCH_PRODUCT)
1013		if (id->product != dev->id.product)
1014			return false;
1015
1016	if (id->flags & INPUT_DEVICE_ID_MATCH_VERSION)
1017		if (id->version != dev->id.version)
1018			return false;
1019
1020	if (!bitmap_subset(id->evbit, dev->evbit, EV_MAX) ||
1021	    !bitmap_subset(id->keybit, dev->keybit, KEY_MAX) ||
1022	    !bitmap_subset(id->relbit, dev->relbit, REL_MAX) ||
1023	    !bitmap_subset(id->absbit, dev->absbit, ABS_MAX) ||
1024	    !bitmap_subset(id->mscbit, dev->mscbit, MSC_MAX) ||
1025	    !bitmap_subset(id->ledbit, dev->ledbit, LED_MAX) ||
1026	    !bitmap_subset(id->sndbit, dev->sndbit, SND_MAX) ||
1027	    !bitmap_subset(id->ffbit, dev->ffbit, FF_MAX) ||
1028	    !bitmap_subset(id->swbit, dev->swbit, SW_MAX) ||
1029	    !bitmap_subset(id->propbit, dev->propbit, INPUT_PROP_MAX)) {
1030		return false;
1031	}
1032
1033	return true;
1034}
1035EXPORT_SYMBOL(input_match_device_id);
1036
1037static const struct input_device_id *input_match_device(struct input_handler *handler,
1038							struct input_dev *dev)
1039{
1040	const struct input_device_id *id;
1041
1042	for (id = handler->id_table; id->flags || id->driver_info; id++) {
1043		if (input_match_device_id(dev, id) &&
1044		    (!handler->match || handler->match(handler, dev))) {
1045			return id;
1046		}
1047	}
1048
1049	return NULL;
1050}
1051
1052static int input_attach_handler(struct input_dev *dev, struct input_handler *handler)
1053{
1054	const struct input_device_id *id;
1055	int error;
1056
1057	id = input_match_device(handler, dev);
1058	if (!id)
1059		return -ENODEV;
1060
1061	error = handler->connect(handler, dev, id);
1062	if (error && error != -ENODEV)
1063		pr_err("failed to attach handler %s to device %s, error: %d\n",
1064		       handler->name, kobject_name(&dev->dev.kobj), error);
1065
1066	return error;
1067}
1068
1069#ifdef CONFIG_COMPAT
1070
1071static int input_bits_to_string(char *buf, int buf_size,
1072				unsigned long bits, bool skip_empty)
1073{
1074	int len = 0;
1075
1076	if (in_compat_syscall()) {
1077		u32 dword = bits >> 32;
1078		if (dword || !skip_empty)
1079			len += snprintf(buf, buf_size, "%x ", dword);
1080
1081		dword = bits & 0xffffffffUL;
1082		if (dword || !skip_empty || len)
1083			len += snprintf(buf + len, max(buf_size - len, 0),
1084					"%x", dword);
1085	} else {
1086		if (bits || !skip_empty)
1087			len += snprintf(buf, buf_size, "%lx", bits);
1088	}
1089
1090	return len;
1091}
1092
1093#else /* !CONFIG_COMPAT */
1094
1095static int input_bits_to_string(char *buf, int buf_size,
1096				unsigned long bits, bool skip_empty)
1097{
1098	return bits || !skip_empty ?
1099		snprintf(buf, buf_size, "%lx", bits) : 0;
1100}
1101
1102#endif
1103
1104#ifdef CONFIG_PROC_FS
1105
1106static struct proc_dir_entry *proc_bus_input_dir;
1107static DECLARE_WAIT_QUEUE_HEAD(input_devices_poll_wait);
1108static int input_devices_state;
1109
1110static inline void input_wakeup_procfs_readers(void)
1111{
1112	input_devices_state++;
1113	wake_up(&input_devices_poll_wait);
1114}
1115
1116static __poll_t input_proc_devices_poll(struct file *file, poll_table *wait)
1117{
1118	poll_wait(file, &input_devices_poll_wait, wait);
1119	if (file->f_version != input_devices_state) {
1120		file->f_version = input_devices_state;
1121		return EPOLLIN | EPOLLRDNORM;
1122	}
1123
1124	return 0;
1125}
1126
1127union input_seq_state {
1128	struct {
1129		unsigned short pos;
1130		bool mutex_acquired;
1131	};
1132	void *p;
1133};
1134
1135static void *input_devices_seq_start(struct seq_file *seq, loff_t *pos)
1136{
1137	union input_seq_state *state = (union input_seq_state *)&seq->private;
1138	int error;
1139
1140	/* We need to fit into seq->private pointer */
1141	BUILD_BUG_ON(sizeof(union input_seq_state) != sizeof(seq->private));
1142
1143	error = mutex_lock_interruptible(&input_mutex);
1144	if (error) {
1145		state->mutex_acquired = false;
1146		return ERR_PTR(error);
1147	}
1148
1149	state->mutex_acquired = true;
1150
1151	return seq_list_start(&input_dev_list, *pos);
1152}
1153
1154static void *input_devices_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1155{
1156	return seq_list_next(v, &input_dev_list, pos);
1157}
1158
1159static void input_seq_stop(struct seq_file *seq, void *v)
1160{
1161	union input_seq_state *state = (union input_seq_state *)&seq->private;
1162
1163	if (state->mutex_acquired)
1164		mutex_unlock(&input_mutex);
1165}
1166
1167static void input_seq_print_bitmap(struct seq_file *seq, const char *name,
1168				   unsigned long *bitmap, int max)
1169{
1170	int i;
1171	bool skip_empty = true;
1172	char buf[18];
1173
1174	seq_printf(seq, "B: %s=", name);
1175
1176	for (i = BITS_TO_LONGS(max) - 1; i >= 0; i--) {
1177		if (input_bits_to_string(buf, sizeof(buf),
1178					 bitmap[i], skip_empty)) {
1179			skip_empty = false;
1180			seq_printf(seq, "%s%s", buf, i > 0 ? " " : "");
1181		}
1182	}
1183
1184	/*
1185	 * If no output was produced print a single 0.
1186	 */
1187	if (skip_empty)
1188		seq_putc(seq, '0');
1189
1190	seq_putc(seq, '\n');
1191}
1192
1193static int input_devices_seq_show(struct seq_file *seq, void *v)
1194{
1195	struct input_dev *dev = container_of(v, struct input_dev, node);
1196	const char *path = kobject_get_path(&dev->dev.kobj, GFP_KERNEL);
1197	struct input_handle *handle;
1198
1199	seq_printf(seq, "I: Bus=%04x Vendor=%04x Product=%04x Version=%04x\n",
1200		   dev->id.bustype, dev->id.vendor, dev->id.product, dev->id.version);
1201
1202	seq_printf(seq, "N: Name=\"%s\"\n", dev->name ? dev->name : "");
1203	seq_printf(seq, "P: Phys=%s\n", dev->phys ? dev->phys : "");
1204	seq_printf(seq, "S: Sysfs=%s\n", path ? path : "");
1205	seq_printf(seq, "U: Uniq=%s\n", dev->uniq ? dev->uniq : "");
1206	seq_puts(seq, "H: Handlers=");
1207
1208	list_for_each_entry(handle, &dev->h_list, d_node)
1209		seq_printf(seq, "%s ", handle->name);
1210	seq_putc(seq, '\n');
1211
1212	input_seq_print_bitmap(seq, "PROP", dev->propbit, INPUT_PROP_MAX);
1213
1214	input_seq_print_bitmap(seq, "EV", dev->evbit, EV_MAX);
1215	if (test_bit(EV_KEY, dev->evbit))
1216		input_seq_print_bitmap(seq, "KEY", dev->keybit, KEY_MAX);
1217	if (test_bit(EV_REL, dev->evbit))
1218		input_seq_print_bitmap(seq, "REL", dev->relbit, REL_MAX);
1219	if (test_bit(EV_ABS, dev->evbit))
1220		input_seq_print_bitmap(seq, "ABS", dev->absbit, ABS_MAX);
1221	if (test_bit(EV_MSC, dev->evbit))
1222		input_seq_print_bitmap(seq, "MSC", dev->mscbit, MSC_MAX);
1223	if (test_bit(EV_LED, dev->evbit))
1224		input_seq_print_bitmap(seq, "LED", dev->ledbit, LED_MAX);
1225	if (test_bit(EV_SND, dev->evbit))
1226		input_seq_print_bitmap(seq, "SND", dev->sndbit, SND_MAX);
1227	if (test_bit(EV_FF, dev->evbit))
1228		input_seq_print_bitmap(seq, "FF", dev->ffbit, FF_MAX);
1229	if (test_bit(EV_SW, dev->evbit))
1230		input_seq_print_bitmap(seq, "SW", dev->swbit, SW_MAX);
1231
1232	seq_putc(seq, '\n');
1233
1234	kfree(path);
1235	return 0;
1236}
1237
1238static const struct seq_operations input_devices_seq_ops = {
1239	.start	= input_devices_seq_start,
1240	.next	= input_devices_seq_next,
1241	.stop	= input_seq_stop,
1242	.show	= input_devices_seq_show,
1243};
1244
1245static int input_proc_devices_open(struct inode *inode, struct file *file)
1246{
1247	return seq_open(file, &input_devices_seq_ops);
1248}
1249
1250static const struct proc_ops input_devices_proc_ops = {
1251	.proc_open	= input_proc_devices_open,
1252	.proc_poll	= input_proc_devices_poll,
1253	.proc_read	= seq_read,
1254	.proc_lseek	= seq_lseek,
1255	.proc_release	= seq_release,
1256};
1257
1258static void *input_handlers_seq_start(struct seq_file *seq, loff_t *pos)
1259{
1260	union input_seq_state *state = (union input_seq_state *)&seq->private;
1261	int error;
1262
1263	/* We need to fit into seq->private pointer */
1264	BUILD_BUG_ON(sizeof(union input_seq_state) != sizeof(seq->private));
1265
1266	error = mutex_lock_interruptible(&input_mutex);
1267	if (error) {
1268		state->mutex_acquired = false;
1269		return ERR_PTR(error);
1270	}
1271
1272	state->mutex_acquired = true;
1273	state->pos = *pos;
1274
1275	return seq_list_start(&input_handler_list, *pos);
1276}
1277
1278static void *input_handlers_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1279{
1280	union input_seq_state *state = (union input_seq_state *)&seq->private;
1281
1282	state->pos = *pos + 1;
1283	return seq_list_next(v, &input_handler_list, pos);
1284}
1285
1286static int input_handlers_seq_show(struct seq_file *seq, void *v)
1287{
1288	struct input_handler *handler = container_of(v, struct input_handler, node);
1289	union input_seq_state *state = (union input_seq_state *)&seq->private;
1290
1291	seq_printf(seq, "N: Number=%u Name=%s", state->pos, handler->name);
1292	if (handler->filter)
1293		seq_puts(seq, " (filter)");
1294	if (handler->legacy_minors)
1295		seq_printf(seq, " Minor=%d", handler->minor);
1296	seq_putc(seq, '\n');
1297
1298	return 0;
1299}
1300
1301static const struct seq_operations input_handlers_seq_ops = {
1302	.start	= input_handlers_seq_start,
1303	.next	= input_handlers_seq_next,
1304	.stop	= input_seq_stop,
1305	.show	= input_handlers_seq_show,
1306};
1307
1308static int input_proc_handlers_open(struct inode *inode, struct file *file)
1309{
1310	return seq_open(file, &input_handlers_seq_ops);
1311}
1312
1313static const struct proc_ops input_handlers_proc_ops = {
1314	.proc_open	= input_proc_handlers_open,
1315	.proc_read	= seq_read,
1316	.proc_lseek	= seq_lseek,
1317	.proc_release	= seq_release,
1318};
1319
1320static int __init input_proc_init(void)
1321{
1322	struct proc_dir_entry *entry;
1323
1324	proc_bus_input_dir = proc_mkdir("bus/input", NULL);
1325	if (!proc_bus_input_dir)
1326		return -ENOMEM;
1327
1328	entry = proc_create("devices", 0, proc_bus_input_dir,
1329			    &input_devices_proc_ops);
1330	if (!entry)
1331		goto fail1;
1332
1333	entry = proc_create("handlers", 0, proc_bus_input_dir,
1334			    &input_handlers_proc_ops);
1335	if (!entry)
1336		goto fail2;
1337
1338	return 0;
1339
1340 fail2:	remove_proc_entry("devices", proc_bus_input_dir);
1341 fail1: remove_proc_entry("bus/input", NULL);
1342	return -ENOMEM;
1343}
1344
1345static void input_proc_exit(void)
1346{
1347	remove_proc_entry("devices", proc_bus_input_dir);
1348	remove_proc_entry("handlers", proc_bus_input_dir);
1349	remove_proc_entry("bus/input", NULL);
1350}
1351
1352#else /* !CONFIG_PROC_FS */
1353static inline void input_wakeup_procfs_readers(void) { }
1354static inline int input_proc_init(void) { return 0; }
1355static inline void input_proc_exit(void) { }
1356#endif
1357
1358#define INPUT_DEV_STRING_ATTR_SHOW(name)				\
1359static ssize_t input_dev_show_##name(struct device *dev,		\
1360				     struct device_attribute *attr,	\
1361				     char *buf)				\
1362{									\
1363	struct input_dev *input_dev = to_input_dev(dev);		\
1364									\
1365	return scnprintf(buf, PAGE_SIZE, "%s\n",			\
1366			 input_dev->name ? input_dev->name : "");	\
1367}									\
1368static DEVICE_ATTR(name, S_IRUGO, input_dev_show_##name, NULL)
1369
1370INPUT_DEV_STRING_ATTR_SHOW(name);
1371INPUT_DEV_STRING_ATTR_SHOW(phys);
1372INPUT_DEV_STRING_ATTR_SHOW(uniq);
1373
1374static int input_print_modalias_bits(char *buf, int size,
1375				     char name, unsigned long *bm,
1376				     unsigned int min_bit, unsigned int max_bit)
1377{
1378	int len = 0, i;
1379
1380	len += snprintf(buf, max(size, 0), "%c", name);
1381	for (i = min_bit; i < max_bit; i++)
1382		if (bm[BIT_WORD(i)] & BIT_MASK(i))
1383			len += snprintf(buf + len, max(size - len, 0), "%X,", i);
1384	return len;
1385}
1386
1387static int input_print_modalias(char *buf, int size, struct input_dev *id,
1388				int add_cr)
1389{
1390	int len;
1391
1392	len = snprintf(buf, max(size, 0),
1393		       "input:b%04Xv%04Xp%04Xe%04X-",
1394		       id->id.bustype, id->id.vendor,
1395		       id->id.product, id->id.version);
1396
1397	len += input_print_modalias_bits(buf + len, size - len,
1398				'e', id->evbit, 0, EV_MAX);
1399	len += input_print_modalias_bits(buf + len, size - len,
1400				'k', id->keybit, KEY_MIN_INTERESTING, KEY_MAX);
1401	len += input_print_modalias_bits(buf + len, size - len,
1402				'r', id->relbit, 0, REL_MAX);
1403	len += input_print_modalias_bits(buf + len, size - len,
1404				'a', id->absbit, 0, ABS_MAX);
1405	len += input_print_modalias_bits(buf + len, size - len,
1406				'm', id->mscbit, 0, MSC_MAX);
1407	len += input_print_modalias_bits(buf + len, size - len,
1408				'l', id->ledbit, 0, LED_MAX);
1409	len += input_print_modalias_bits(buf + len, size - len,
1410				's', id->sndbit, 0, SND_MAX);
1411	len += input_print_modalias_bits(buf + len, size - len,
1412				'f', id->ffbit, 0, FF_MAX);
1413	len += input_print_modalias_bits(buf + len, size - len,
1414				'w', id->swbit, 0, SW_MAX);
1415
1416	if (add_cr)
1417		len += snprintf(buf + len, max(size - len, 0), "\n");
1418
1419	return len;
1420}
1421
1422static ssize_t input_dev_show_modalias(struct device *dev,
1423				       struct device_attribute *attr,
1424				       char *buf)
1425{
1426	struct input_dev *id = to_input_dev(dev);
1427	ssize_t len;
1428
1429	len = input_print_modalias(buf, PAGE_SIZE, id, 1);
1430
1431	return min_t(int, len, PAGE_SIZE);
1432}
1433static DEVICE_ATTR(modalias, S_IRUGO, input_dev_show_modalias, NULL);
1434
1435static int input_print_bitmap(char *buf, int buf_size, unsigned long *bitmap,
1436			      int max, int add_cr);
1437
1438static ssize_t input_dev_show_properties(struct device *dev,
1439					 struct device_attribute *attr,
1440					 char *buf)
1441{
1442	struct input_dev *input_dev = to_input_dev(dev);
1443	int len = input_print_bitmap(buf, PAGE_SIZE, input_dev->propbit,
1444				     INPUT_PROP_MAX, true);
1445	return min_t(int, len, PAGE_SIZE);
1446}
1447static DEVICE_ATTR(properties, S_IRUGO, input_dev_show_properties, NULL);
1448
1449static int input_inhibit_device(struct input_dev *dev);
1450static int input_uninhibit_device(struct input_dev *dev);
1451
1452static ssize_t inhibited_show(struct device *dev,
1453			      struct device_attribute *attr,
1454			      char *buf)
1455{
1456	struct input_dev *input_dev = to_input_dev(dev);
1457
1458	return scnprintf(buf, PAGE_SIZE, "%d\n", input_dev->inhibited);
1459}
1460
1461static ssize_t inhibited_store(struct device *dev,
1462			       struct device_attribute *attr, const char *buf,
1463			       size_t len)
1464{
1465	struct input_dev *input_dev = to_input_dev(dev);
1466	ssize_t rv;
1467	bool inhibited;
1468
1469	if (kstrtobool(buf, &inhibited))
1470		return -EINVAL;
1471
1472	if (inhibited)
1473		rv = input_inhibit_device(input_dev);
1474	else
1475		rv = input_uninhibit_device(input_dev);
1476
1477	if (rv != 0)
1478		return rv;
1479
1480	return len;
1481}
1482
1483static DEVICE_ATTR_RW(inhibited);
1484
1485static struct attribute *input_dev_attrs[] = {
1486	&dev_attr_name.attr,
1487	&dev_attr_phys.attr,
1488	&dev_attr_uniq.attr,
1489	&dev_attr_modalias.attr,
1490	&dev_attr_properties.attr,
1491	&dev_attr_inhibited.attr,
1492	NULL
1493};
1494
1495static const struct attribute_group input_dev_attr_group = {
1496	.attrs	= input_dev_attrs,
1497};
1498
1499#define INPUT_DEV_ID_ATTR(name)						\
1500static ssize_t input_dev_show_id_##name(struct device *dev,		\
1501					struct device_attribute *attr,	\
1502					char *buf)			\
1503{									\
1504	struct input_dev *input_dev = to_input_dev(dev);		\
1505	return scnprintf(buf, PAGE_SIZE, "%04x\n", input_dev->id.name);	\
1506}									\
1507static DEVICE_ATTR(name, S_IRUGO, input_dev_show_id_##name, NULL)
1508
1509INPUT_DEV_ID_ATTR(bustype);
1510INPUT_DEV_ID_ATTR(vendor);
1511INPUT_DEV_ID_ATTR(product);
1512INPUT_DEV_ID_ATTR(version);
1513
1514static struct attribute *input_dev_id_attrs[] = {
1515	&dev_attr_bustype.attr,
1516	&dev_attr_vendor.attr,
1517	&dev_attr_product.attr,
1518	&dev_attr_version.attr,
1519	NULL
1520};
1521
1522static const struct attribute_group input_dev_id_attr_group = {
1523	.name	= "id",
1524	.attrs	= input_dev_id_attrs,
1525};
1526
1527static int input_print_bitmap(char *buf, int buf_size, unsigned long *bitmap,
1528			      int max, int add_cr)
1529{
1530	int i;
1531	int len = 0;
1532	bool skip_empty = true;
1533
1534	for (i = BITS_TO_LONGS(max) - 1; i >= 0; i--) {
1535		len += input_bits_to_string(buf + len, max(buf_size - len, 0),
1536					    bitmap[i], skip_empty);
1537		if (len) {
1538			skip_empty = false;
1539			if (i > 0)
1540				len += snprintf(buf + len, max(buf_size - len, 0), " ");
1541		}
1542	}
1543
1544	/*
1545	 * If no output was produced print a single 0.
1546	 */
1547	if (len == 0)
1548		len = snprintf(buf, buf_size, "%d", 0);
1549
1550	if (add_cr)
1551		len += snprintf(buf + len, max(buf_size - len, 0), "\n");
1552
1553	return len;
1554}
1555
1556#define INPUT_DEV_CAP_ATTR(ev, bm)					\
1557static ssize_t input_dev_show_cap_##bm(struct device *dev,		\
1558				       struct device_attribute *attr,	\
1559				       char *buf)			\
1560{									\
1561	struct input_dev *input_dev = to_input_dev(dev);		\
1562	int len = input_print_bitmap(buf, PAGE_SIZE,			\
1563				     input_dev->bm##bit, ev##_MAX,	\
1564				     true);				\
1565	return min_t(int, len, PAGE_SIZE);				\
1566}									\
1567static DEVICE_ATTR(bm, S_IRUGO, input_dev_show_cap_##bm, NULL)
1568
1569INPUT_DEV_CAP_ATTR(EV, ev);
1570INPUT_DEV_CAP_ATTR(KEY, key);
1571INPUT_DEV_CAP_ATTR(REL, rel);
1572INPUT_DEV_CAP_ATTR(ABS, abs);
1573INPUT_DEV_CAP_ATTR(MSC, msc);
1574INPUT_DEV_CAP_ATTR(LED, led);
1575INPUT_DEV_CAP_ATTR(SND, snd);
1576INPUT_DEV_CAP_ATTR(FF, ff);
1577INPUT_DEV_CAP_ATTR(SW, sw);
1578
1579static struct attribute *input_dev_caps_attrs[] = {
1580	&dev_attr_ev.attr,
1581	&dev_attr_key.attr,
1582	&dev_attr_rel.attr,
1583	&dev_attr_abs.attr,
1584	&dev_attr_msc.attr,
1585	&dev_attr_led.attr,
1586	&dev_attr_snd.attr,
1587	&dev_attr_ff.attr,
1588	&dev_attr_sw.attr,
1589	NULL
1590};
1591
1592static const struct attribute_group input_dev_caps_attr_group = {
1593	.name	= "capabilities",
1594	.attrs	= input_dev_caps_attrs,
1595};
1596
1597static const struct attribute_group *input_dev_attr_groups[] = {
1598	&input_dev_attr_group,
1599	&input_dev_id_attr_group,
1600	&input_dev_caps_attr_group,
1601	&input_poller_attribute_group,
1602	NULL
1603};
1604
1605static void input_dev_release(struct device *device)
1606{
1607	struct input_dev *dev = to_input_dev(device);
1608
1609	input_ff_destroy(dev);
1610	input_mt_destroy_slots(dev);
1611	kfree(dev->poller);
1612	kfree(dev->absinfo);
1613	kfree(dev->vals);
1614	kfree(dev);
1615
1616	module_put(THIS_MODULE);
1617}
1618
1619/*
1620 * Input uevent interface - loading event handlers based on
1621 * device bitfields.
1622 */
1623static int input_add_uevent_bm_var(struct kobj_uevent_env *env,
1624				   const char *name, unsigned long *bitmap, int max)
1625{
1626	int len;
1627
1628	if (add_uevent_var(env, "%s", name))
1629		return -ENOMEM;
1630
1631	len = input_print_bitmap(&env->buf[env->buflen - 1],
1632				 sizeof(env->buf) - env->buflen,
1633				 bitmap, max, false);
1634	if (len >= (sizeof(env->buf) - env->buflen))
1635		return -ENOMEM;
1636
1637	env->buflen += len;
1638	return 0;
1639}
1640
1641static int input_add_uevent_modalias_var(struct kobj_uevent_env *env,
1642					 struct input_dev *dev)
1643{
1644	int len;
1645
1646	if (add_uevent_var(env, "MODALIAS="))
1647		return -ENOMEM;
1648
1649	len = input_print_modalias(&env->buf[env->buflen - 1],
1650				   sizeof(env->buf) - env->buflen,
1651				   dev, 0);
1652	if (len >= (sizeof(env->buf) - env->buflen))
1653		return -ENOMEM;
1654
1655	env->buflen += len;
1656	return 0;
1657}
1658
1659#define INPUT_ADD_HOTPLUG_VAR(fmt, val...)				\
1660	do {								\
1661		int err = add_uevent_var(env, fmt, val);		\
1662		if (err)						\
1663			return err;					\
1664	} while (0)
1665
1666#define INPUT_ADD_HOTPLUG_BM_VAR(name, bm, max)				\
1667	do {								\
1668		int err = input_add_uevent_bm_var(env, name, bm, max);	\
1669		if (err)						\
1670			return err;					\
1671	} while (0)
1672
1673#define INPUT_ADD_HOTPLUG_MODALIAS_VAR(dev)				\
1674	do {								\
1675		int err = input_add_uevent_modalias_var(env, dev);	\
1676		if (err)						\
1677			return err;					\
1678	} while (0)
1679
1680static int input_dev_uevent(struct device *device, struct kobj_uevent_env *env)
1681{
1682	struct input_dev *dev = to_input_dev(device);
1683
1684	INPUT_ADD_HOTPLUG_VAR("PRODUCT=%x/%x/%x/%x",
1685				dev->id.bustype, dev->id.vendor,
1686				dev->id.product, dev->id.version);
1687	if (dev->name)
1688		INPUT_ADD_HOTPLUG_VAR("NAME=\"%s\"", dev->name);
1689	if (dev->phys)
1690		INPUT_ADD_HOTPLUG_VAR("PHYS=\"%s\"", dev->phys);
1691	if (dev->uniq)
1692		INPUT_ADD_HOTPLUG_VAR("UNIQ=\"%s\"", dev->uniq);
1693
1694	INPUT_ADD_HOTPLUG_BM_VAR("PROP=", dev->propbit, INPUT_PROP_MAX);
1695
1696	INPUT_ADD_HOTPLUG_BM_VAR("EV=", dev->evbit, EV_MAX);
1697	if (test_bit(EV_KEY, dev->evbit))
1698		INPUT_ADD_HOTPLUG_BM_VAR("KEY=", dev->keybit, KEY_MAX);
1699	if (test_bit(EV_REL, dev->evbit))
1700		INPUT_ADD_HOTPLUG_BM_VAR("REL=", dev->relbit, REL_MAX);
1701	if (test_bit(EV_ABS, dev->evbit))
1702		INPUT_ADD_HOTPLUG_BM_VAR("ABS=", dev->absbit, ABS_MAX);
1703	if (test_bit(EV_MSC, dev->evbit))
1704		INPUT_ADD_HOTPLUG_BM_VAR("MSC=", dev->mscbit, MSC_MAX);
1705	if (test_bit(EV_LED, dev->evbit))
1706		INPUT_ADD_HOTPLUG_BM_VAR("LED=", dev->ledbit, LED_MAX);
1707	if (test_bit(EV_SND, dev->evbit))
1708		INPUT_ADD_HOTPLUG_BM_VAR("SND=", dev->sndbit, SND_MAX);
1709	if (test_bit(EV_FF, dev->evbit))
1710		INPUT_ADD_HOTPLUG_BM_VAR("FF=", dev->ffbit, FF_MAX);
1711	if (test_bit(EV_SW, dev->evbit))
1712		INPUT_ADD_HOTPLUG_BM_VAR("SW=", dev->swbit, SW_MAX);
1713
1714	INPUT_ADD_HOTPLUG_MODALIAS_VAR(dev);
1715
1716	return 0;
1717}
1718
1719#define INPUT_DO_TOGGLE(dev, type, bits, on)				\
1720	do {								\
1721		int i;							\
1722		bool active;						\
1723									\
1724		if (!test_bit(EV_##type, dev->evbit))			\
1725			break;						\
1726									\
1727		for_each_set_bit(i, dev->bits##bit, type##_CNT) {	\
1728			active = test_bit(i, dev->bits);		\
1729			if (!active && !on)				\
1730				continue;				\
1731									\
1732			dev->event(dev, EV_##type, i, on ? active : 0);	\
1733		}							\
1734	} while (0)
1735
1736static void input_dev_toggle(struct input_dev *dev, bool activate)
1737{
1738	if (!dev->event)
1739		return;
1740
1741	INPUT_DO_TOGGLE(dev, LED, led, activate);
1742	INPUT_DO_TOGGLE(dev, SND, snd, activate);
1743
1744	if (activate && test_bit(EV_REP, dev->evbit)) {
1745		dev->event(dev, EV_REP, REP_PERIOD, dev->rep[REP_PERIOD]);
1746		dev->event(dev, EV_REP, REP_DELAY, dev->rep[REP_DELAY]);
1747	}
1748}
1749
1750/**
1751 * input_reset_device() - reset/restore the state of input device
1752 * @dev: input device whose state needs to be reset
1753 *
1754 * This function tries to reset the state of an opened input device and
1755 * bring internal state and state if the hardware in sync with each other.
1756 * We mark all keys as released, restore LED state, repeat rate, etc.
1757 */
1758void input_reset_device(struct input_dev *dev)
1759{
1760	unsigned long flags;
1761
1762	mutex_lock(&dev->mutex);
1763	spin_lock_irqsave(&dev->event_lock, flags);
1764
1765	input_dev_toggle(dev, true);
1766	if (input_dev_release_keys(dev))
1767		input_handle_event(dev, EV_SYN, SYN_REPORT, 1);
1768
1769	spin_unlock_irqrestore(&dev->event_lock, flags);
1770	mutex_unlock(&dev->mutex);
1771}
1772EXPORT_SYMBOL(input_reset_device);
1773
1774static int input_inhibit_device(struct input_dev *dev)
1775{
1776	mutex_lock(&dev->mutex);
1777
1778	if (dev->inhibited)
1779		goto out;
1780
1781	if (dev->users) {
1782		if (dev->close)
1783			dev->close(dev);
1784		if (dev->poller)
1785			input_dev_poller_stop(dev->poller);
1786	}
1787
1788	spin_lock_irq(&dev->event_lock);
1789	input_mt_release_slots(dev);
1790	input_dev_release_keys(dev);
1791	input_handle_event(dev, EV_SYN, SYN_REPORT, 1);
1792	input_dev_toggle(dev, false);
1793	spin_unlock_irq(&dev->event_lock);
1794
1795	dev->inhibited = true;
1796
1797out:
1798	mutex_unlock(&dev->mutex);
1799	return 0;
1800}
1801
1802static int input_uninhibit_device(struct input_dev *dev)
1803{
1804	int ret = 0;
1805
1806	mutex_lock(&dev->mutex);
1807
1808	if (!dev->inhibited)
1809		goto out;
1810
1811	if (dev->users) {
1812		if (dev->open) {
1813			ret = dev->open(dev);
1814			if (ret)
1815				goto out;
1816		}
1817		if (dev->poller)
1818			input_dev_poller_start(dev->poller);
1819	}
1820
1821	dev->inhibited = false;
1822	spin_lock_irq(&dev->event_lock);
1823	input_dev_toggle(dev, true);
1824	spin_unlock_irq(&dev->event_lock);
1825
1826out:
1827	mutex_unlock(&dev->mutex);
1828	return ret;
1829}
1830
1831#ifdef CONFIG_PM_SLEEP
1832static int input_dev_suspend(struct device *dev)
1833{
1834	struct input_dev *input_dev = to_input_dev(dev);
1835
1836	spin_lock_irq(&input_dev->event_lock);
1837
1838	/*
1839	 * Keys that are pressed now are unlikely to be
1840	 * still pressed when we resume.
1841	 */
1842	if (input_dev_release_keys(input_dev))
1843		input_handle_event(input_dev, EV_SYN, SYN_REPORT, 1);
1844
1845	/* Turn off LEDs and sounds, if any are active. */
1846	input_dev_toggle(input_dev, false);
1847
1848	spin_unlock_irq(&input_dev->event_lock);
1849
1850	return 0;
1851}
1852
1853static int input_dev_resume(struct device *dev)
1854{
1855	struct input_dev *input_dev = to_input_dev(dev);
1856
1857	spin_lock_irq(&input_dev->event_lock);
1858
1859	/* Restore state of LEDs and sounds, if any were active. */
1860	input_dev_toggle(input_dev, true);
1861
1862	spin_unlock_irq(&input_dev->event_lock);
1863
1864	return 0;
1865}
1866
1867static int input_dev_freeze(struct device *dev)
1868{
1869	struct input_dev *input_dev = to_input_dev(dev);
1870
1871	spin_lock_irq(&input_dev->event_lock);
1872
1873	/*
1874	 * Keys that are pressed now are unlikely to be
1875	 * still pressed when we resume.
1876	 */
1877	if (input_dev_release_keys(input_dev))
1878		input_handle_event(input_dev, EV_SYN, SYN_REPORT, 1);
1879
1880	spin_unlock_irq(&input_dev->event_lock);
1881
1882	return 0;
1883}
1884
1885static int input_dev_poweroff(struct device *dev)
1886{
1887	struct input_dev *input_dev = to_input_dev(dev);
1888
1889	spin_lock_irq(&input_dev->event_lock);
1890
1891	/* Turn off LEDs and sounds, if any are active. */
1892	input_dev_toggle(input_dev, false);
1893
1894	spin_unlock_irq(&input_dev->event_lock);
1895
1896	return 0;
1897}
1898
1899static const struct dev_pm_ops input_dev_pm_ops = {
1900	.suspend	= input_dev_suspend,
1901	.resume		= input_dev_resume,
1902	.freeze		= input_dev_freeze,
1903	.poweroff	= input_dev_poweroff,
1904	.restore	= input_dev_resume,
1905};
1906#endif /* CONFIG_PM */
1907
1908static const struct device_type input_dev_type = {
1909	.groups		= input_dev_attr_groups,
1910	.release	= input_dev_release,
1911	.uevent		= input_dev_uevent,
1912#ifdef CONFIG_PM_SLEEP
1913	.pm		= &input_dev_pm_ops,
1914#endif
1915};
1916
1917static char *input_devnode(const struct device *dev, umode_t *mode)
1918{
1919	return kasprintf(GFP_KERNEL, "input/%s", dev_name(dev));
1920}
1921
1922struct class input_class = {
1923	.name		= "input",
1924	.devnode	= input_devnode,
1925};
1926EXPORT_SYMBOL_GPL(input_class);
1927
1928/**
1929 * input_allocate_device - allocate memory for new input device
1930 *
1931 * Returns prepared struct input_dev or %NULL.
1932 *
1933 * NOTE: Use input_free_device() to free devices that have not been
1934 * registered; input_unregister_device() should be used for already
1935 * registered devices.
1936 */
1937struct input_dev *input_allocate_device(void)
1938{
1939	static atomic_t input_no = ATOMIC_INIT(-1);
1940	struct input_dev *dev;
1941
1942	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1943	if (dev) {
1944		dev->dev.type = &input_dev_type;
1945		dev->dev.class = &input_class;
1946		device_initialize(&dev->dev);
1947		mutex_init(&dev->mutex);
1948		spin_lock_init(&dev->event_lock);
1949		timer_setup(&dev->timer, NULL, 0);
1950		INIT_LIST_HEAD(&dev->h_list);
1951		INIT_LIST_HEAD(&dev->node);
1952
1953		dev_set_name(&dev->dev, "input%lu",
1954			     (unsigned long)atomic_inc_return(&input_no));
1955
1956		__module_get(THIS_MODULE);
1957	}
1958
1959	return dev;
1960}
1961EXPORT_SYMBOL(input_allocate_device);
1962
1963struct input_devres {
1964	struct input_dev *input;
1965};
1966
1967static int devm_input_device_match(struct device *dev, void *res, void *data)
1968{
1969	struct input_devres *devres = res;
1970
1971	return devres->input == data;
1972}
1973
1974static void devm_input_device_release(struct device *dev, void *res)
1975{
1976	struct input_devres *devres = res;
1977	struct input_dev *input = devres->input;
1978
1979	dev_dbg(dev, "%s: dropping reference to %s\n",
1980		__func__, dev_name(&input->dev));
1981	input_put_device(input);
1982}
1983
1984/**
1985 * devm_input_allocate_device - allocate managed input device
1986 * @dev: device owning the input device being created
1987 *
1988 * Returns prepared struct input_dev or %NULL.
1989 *
1990 * Managed input devices do not need to be explicitly unregistered or
1991 * freed as it will be done automatically when owner device unbinds from
1992 * its driver (or binding fails). Once managed input device is allocated,
1993 * it is ready to be set up and registered in the same fashion as regular
1994 * input device. There are no special devm_input_device_[un]register()
1995 * variants, regular ones work with both managed and unmanaged devices,
1996 * should you need them. In most cases however, managed input device need
1997 * not be explicitly unregistered or freed.
1998 *
1999 * NOTE: the owner device is set up as parent of input device and users
2000 * should not override it.
2001 */
2002struct input_dev *devm_input_allocate_device(struct device *dev)
2003{
2004	struct input_dev *input;
2005	struct input_devres *devres;
2006
2007	devres = devres_alloc(devm_input_device_release,
2008			      sizeof(*devres), GFP_KERNEL);
2009	if (!devres)
2010		return NULL;
2011
2012	input = input_allocate_device();
2013	if (!input) {
2014		devres_free(devres);
2015		return NULL;
2016	}
2017
2018	input->dev.parent = dev;
2019	input->devres_managed = true;
2020
2021	devres->input = input;
2022	devres_add(dev, devres);
2023
2024	return input;
2025}
2026EXPORT_SYMBOL(devm_input_allocate_device);
2027
2028/**
2029 * input_free_device - free memory occupied by input_dev structure
2030 * @dev: input device to free
2031 *
2032 * This function should only be used if input_register_device()
2033 * was not called yet or if it failed. Once device was registered
2034 * use input_unregister_device() and memory will be freed once last
2035 * reference to the device is dropped.
2036 *
2037 * Device should be allocated by input_allocate_device().
2038 *
2039 * NOTE: If there are references to the input device then memory
2040 * will not be freed until last reference is dropped.
2041 */
2042void input_free_device(struct input_dev *dev)
2043{
2044	if (dev) {
2045		if (dev->devres_managed)
2046			WARN_ON(devres_destroy(dev->dev.parent,
2047						devm_input_device_release,
2048						devm_input_device_match,
2049						dev));
2050		input_put_device(dev);
2051	}
2052}
2053EXPORT_SYMBOL(input_free_device);
2054
2055/**
2056 * input_set_timestamp - set timestamp for input events
2057 * @dev: input device to set timestamp for
2058 * @timestamp: the time at which the event has occurred
2059 *   in CLOCK_MONOTONIC
2060 *
2061 * This function is intended to provide to the input system a more
2062 * accurate time of when an event actually occurred. The driver should
2063 * call this function as soon as a timestamp is acquired ensuring
2064 * clock conversions in input_set_timestamp are done correctly.
2065 *
2066 * The system entering suspend state between timestamp acquisition and
2067 * calling input_set_timestamp can result in inaccurate conversions.
2068 */
2069void input_set_timestamp(struct input_dev *dev, ktime_t timestamp)
2070{
2071	dev->timestamp[INPUT_CLK_MONO] = timestamp;
2072	dev->timestamp[INPUT_CLK_REAL] = ktime_mono_to_real(timestamp);
2073	dev->timestamp[INPUT_CLK_BOOT] = ktime_mono_to_any(timestamp,
2074							   TK_OFFS_BOOT);
2075}
2076EXPORT_SYMBOL(input_set_timestamp);
2077
2078/**
2079 * input_get_timestamp - get timestamp for input events
2080 * @dev: input device to get timestamp from
2081 *
2082 * A valid timestamp is a timestamp of non-zero value.
2083 */
2084ktime_t *input_get_timestamp(struct input_dev *dev)
2085{
2086	const ktime_t invalid_timestamp = ktime_set(0, 0);
2087
2088	if (!ktime_compare(dev->timestamp[INPUT_CLK_MONO], invalid_timestamp))
2089		input_set_timestamp(dev, ktime_get());
2090
2091	return dev->timestamp;
2092}
2093EXPORT_SYMBOL(input_get_timestamp);
2094
2095/**
2096 * input_set_capability - mark device as capable of a certain event
2097 * @dev: device that is capable of emitting or accepting event
2098 * @type: type of the event (EV_KEY, EV_REL, etc...)
2099 * @code: event code
2100 *
2101 * In addition to setting up corresponding bit in appropriate capability
2102 * bitmap the function also adjusts dev->evbit.
2103 */
2104void input_set_capability(struct input_dev *dev, unsigned int type, unsigned int code)
2105{
2106	if (type < EV_CNT && input_max_code[type] &&
2107	    code > input_max_code[type]) {
2108		pr_err("%s: invalid code %u for type %u\n", __func__, code,
2109		       type);
2110		dump_stack();
2111		return;
2112	}
2113
2114	switch (type) {
2115	case EV_KEY:
2116		__set_bit(code, dev->keybit);
2117		break;
2118
2119	case EV_REL:
2120		__set_bit(code, dev->relbit);
2121		break;
2122
2123	case EV_ABS:
2124		input_alloc_absinfo(dev);
2125		__set_bit(code, dev->absbit);
2126		break;
2127
2128	case EV_MSC:
2129		__set_bit(code, dev->mscbit);
2130		break;
2131
2132	case EV_SW:
2133		__set_bit(code, dev->swbit);
2134		break;
2135
2136	case EV_LED:
2137		__set_bit(code, dev->ledbit);
2138		break;
2139
2140	case EV_SND:
2141		__set_bit(code, dev->sndbit);
2142		break;
2143
2144	case EV_FF:
2145		__set_bit(code, dev->ffbit);
2146		break;
2147
2148	case EV_PWR:
2149		/* do nothing */
2150		break;
2151
2152	default:
2153		pr_err("%s: unknown type %u (code %u)\n", __func__, type, code);
2154		dump_stack();
2155		return;
2156	}
2157
2158	__set_bit(type, dev->evbit);
2159}
2160EXPORT_SYMBOL(input_set_capability);
2161
2162static unsigned int input_estimate_events_per_packet(struct input_dev *dev)
2163{
2164	int mt_slots;
2165	int i;
2166	unsigned int events;
2167
2168	if (dev->mt) {
2169		mt_slots = dev->mt->num_slots;
2170	} else if (test_bit(ABS_MT_TRACKING_ID, dev->absbit)) {
2171		mt_slots = dev->absinfo[ABS_MT_TRACKING_ID].maximum -
2172			   dev->absinfo[ABS_MT_TRACKING_ID].minimum + 1,
2173		mt_slots = clamp(mt_slots, 2, 32);
2174	} else if (test_bit(ABS_MT_POSITION_X, dev->absbit)) {
2175		mt_slots = 2;
2176	} else {
2177		mt_slots = 0;
2178	}
2179
2180	events = mt_slots + 1; /* count SYN_MT_REPORT and SYN_REPORT */
2181
2182	if (test_bit(EV_ABS, dev->evbit))
2183		for_each_set_bit(i, dev->absbit, ABS_CNT)
2184			events += input_is_mt_axis(i) ? mt_slots : 1;
2185
2186	if (test_bit(EV_REL, dev->evbit))
2187		events += bitmap_weight(dev->relbit, REL_CNT);
2188
2189	/* Make room for KEY and MSC events */
2190	events += 7;
2191
2192	return events;
2193}
2194
2195#define INPUT_CLEANSE_BITMASK(dev, type, bits)				\
2196	do {								\
2197		if (!test_bit(EV_##type, dev->evbit))			\
2198			memset(dev->bits##bit, 0,			\
2199				sizeof(dev->bits##bit));		\
2200	} while (0)
2201
2202static void input_cleanse_bitmasks(struct input_dev *dev)
2203{
2204	INPUT_CLEANSE_BITMASK(dev, KEY, key);
2205	INPUT_CLEANSE_BITMASK(dev, REL, rel);
2206	INPUT_CLEANSE_BITMASK(dev, ABS, abs);
2207	INPUT_CLEANSE_BITMASK(dev, MSC, msc);
2208	INPUT_CLEANSE_BITMASK(dev, LED, led);
2209	INPUT_CLEANSE_BITMASK(dev, SND, snd);
2210	INPUT_CLEANSE_BITMASK(dev, FF, ff);
2211	INPUT_CLEANSE_BITMASK(dev, SW, sw);
2212}
2213
2214static void __input_unregister_device(struct input_dev *dev)
2215{
2216	struct input_handle *handle, *next;
2217
2218	input_disconnect_device(dev);
2219
2220	mutex_lock(&input_mutex);
2221
2222	list_for_each_entry_safe(handle, next, &dev->h_list, d_node)
2223		handle->handler->disconnect(handle);
2224	WARN_ON(!list_empty(&dev->h_list));
2225
2226	del_timer_sync(&dev->timer);
2227	list_del_init(&dev->node);
2228
2229	input_wakeup_procfs_readers();
2230
2231	mutex_unlock(&input_mutex);
2232
2233	device_del(&dev->dev);
2234}
2235
2236static void devm_input_device_unregister(struct device *dev, void *res)
2237{
2238	struct input_devres *devres = res;
2239	struct input_dev *input = devres->input;
2240
2241	dev_dbg(dev, "%s: unregistering device %s\n",
2242		__func__, dev_name(&input->dev));
2243	__input_unregister_device(input);
2244}
2245
2246/*
2247 * Generate software autorepeat event. Note that we take
2248 * dev->event_lock here to avoid racing with input_event
2249 * which may cause keys get "stuck".
2250 */
2251static void input_repeat_key(struct timer_list *t)
2252{
2253	struct input_dev *dev = from_timer(dev, t, timer);
2254	unsigned long flags;
2255
2256	spin_lock_irqsave(&dev->event_lock, flags);
2257
2258	if (!dev->inhibited &&
2259	    test_bit(dev->repeat_key, dev->key) &&
2260	    is_event_supported(dev->repeat_key, dev->keybit, KEY_MAX)) {
2261
2262		input_set_timestamp(dev, ktime_get());
2263		input_handle_event(dev, EV_KEY, dev->repeat_key, 2);
2264		input_handle_event(dev, EV_SYN, SYN_REPORT, 1);
2265
2266		if (dev->rep[REP_PERIOD])
2267			mod_timer(&dev->timer, jiffies +
2268					msecs_to_jiffies(dev->rep[REP_PERIOD]));
2269	}
2270
2271	spin_unlock_irqrestore(&dev->event_lock, flags);
2272}
2273
2274/**
2275 * input_enable_softrepeat - enable software autorepeat
2276 * @dev: input device
2277 * @delay: repeat delay
2278 * @period: repeat period
2279 *
2280 * Enable software autorepeat on the input device.
2281 */
2282void input_enable_softrepeat(struct input_dev *dev, int delay, int period)
2283{
2284	dev->timer.function = input_repeat_key;
2285	dev->rep[REP_DELAY] = delay;
2286	dev->rep[REP_PERIOD] = period;
2287}
2288EXPORT_SYMBOL(input_enable_softrepeat);
2289
2290bool input_device_enabled(struct input_dev *dev)
2291{
2292	lockdep_assert_held(&dev->mutex);
2293
2294	return !dev->inhibited && dev->users > 0;
2295}
2296EXPORT_SYMBOL_GPL(input_device_enabled);
2297
2298/**
2299 * input_register_device - register device with input core
2300 * @dev: device to be registered
2301 *
2302 * This function registers device with input core. The device must be
2303 * allocated with input_allocate_device() and all it's capabilities
2304 * set up before registering.
2305 * If function fails the device must be freed with input_free_device().
2306 * Once device has been successfully registered it can be unregistered
2307 * with input_unregister_device(); input_free_device() should not be
2308 * called in this case.
2309 *
2310 * Note that this function is also used to register managed input devices
2311 * (ones allocated with devm_input_allocate_device()). Such managed input
2312 * devices need not be explicitly unregistered or freed, their tear down
2313 * is controlled by the devres infrastructure. It is also worth noting
2314 * that tear down of managed input devices is internally a 2-step process:
2315 * registered managed input device is first unregistered, but stays in
2316 * memory and can still handle input_event() calls (although events will
2317 * not be delivered anywhere). The freeing of managed input device will
2318 * happen later, when devres stack is unwound to the point where device
2319 * allocation was made.
2320 */
2321int input_register_device(struct input_dev *dev)
2322{
2323	struct input_devres *devres = NULL;
2324	struct input_handler *handler;
2325	unsigned int packet_size;
2326	const char *path;
2327	int error;
2328
2329	if (test_bit(EV_ABS, dev->evbit) && !dev->absinfo) {
2330		dev_err(&dev->dev,
2331			"Absolute device without dev->absinfo, refusing to register\n");
2332		return -EINVAL;
2333	}
2334
2335	if (dev->devres_managed) {
2336		devres = devres_alloc(devm_input_device_unregister,
2337				      sizeof(*devres), GFP_KERNEL);
2338		if (!devres)
2339			return -ENOMEM;
2340
2341		devres->input = dev;
2342	}
2343
2344	/* Every input device generates EV_SYN/SYN_REPORT events. */
2345	__set_bit(EV_SYN, dev->evbit);
2346
2347	/* KEY_RESERVED is not supposed to be transmitted to userspace. */
2348	__clear_bit(KEY_RESERVED, dev->keybit);
2349
2350	/* Make sure that bitmasks not mentioned in dev->evbit are clean. */
2351	input_cleanse_bitmasks(dev);
2352
2353	packet_size = input_estimate_events_per_packet(dev);
2354	if (dev->hint_events_per_packet < packet_size)
2355		dev->hint_events_per_packet = packet_size;
2356
2357	dev->max_vals = dev->hint_events_per_packet + 2;
2358	dev->vals = kcalloc(dev->max_vals, sizeof(*dev->vals), GFP_KERNEL);
2359	if (!dev->vals) {
2360		error = -ENOMEM;
2361		goto err_devres_free;
2362	}
2363
2364	/*
2365	 * If delay and period are pre-set by the driver, then autorepeating
2366	 * is handled by the driver itself and we don't do it in input.c.
2367	 */
2368	if (!dev->rep[REP_DELAY] && !dev->rep[REP_PERIOD])
2369		input_enable_softrepeat(dev, 250, 33);
2370
2371	if (!dev->getkeycode)
2372		dev->getkeycode = input_default_getkeycode;
2373
2374	if (!dev->setkeycode)
2375		dev->setkeycode = input_default_setkeycode;
2376
2377	if (dev->poller)
2378		input_dev_poller_finalize(dev->poller);
2379
2380	error = device_add(&dev->dev);
2381	if (error)
2382		goto err_free_vals;
2383
2384	path = kobject_get_path(&dev->dev.kobj, GFP_KERNEL);
2385	pr_info("%s as %s\n",
2386		dev->name ? dev->name : "Unspecified device",
2387		path ? path : "N/A");
2388	kfree(path);
2389
2390	error = mutex_lock_interruptible(&input_mutex);
2391	if (error)
2392		goto err_device_del;
2393
2394	list_add_tail(&dev->node, &input_dev_list);
2395
2396	list_for_each_entry(handler, &input_handler_list, node)
2397		input_attach_handler(dev, handler);
2398
2399	input_wakeup_procfs_readers();
2400
2401	mutex_unlock(&input_mutex);
2402
2403	if (dev->devres_managed) {
2404		dev_dbg(dev->dev.parent, "%s: registering %s with devres.\n",
2405			__func__, dev_name(&dev->dev));
2406		devres_add(dev->dev.parent, devres);
2407	}
2408	return 0;
2409
2410err_device_del:
2411	device_del(&dev->dev);
2412err_free_vals:
2413	kfree(dev->vals);
2414	dev->vals = NULL;
2415err_devres_free:
2416	devres_free(devres);
2417	return error;
2418}
2419EXPORT_SYMBOL(input_register_device);
2420
2421/**
2422 * input_unregister_device - unregister previously registered device
2423 * @dev: device to be unregistered
2424 *
2425 * This function unregisters an input device. Once device is unregistered
2426 * the caller should not try to access it as it may get freed at any moment.
2427 */
2428void input_unregister_device(struct input_dev *dev)
2429{
2430	if (dev->devres_managed) {
2431		WARN_ON(devres_destroy(dev->dev.parent,
2432					devm_input_device_unregister,
2433					devm_input_device_match,
2434					dev));
2435		__input_unregister_device(dev);
2436		/*
2437		 * We do not do input_put_device() here because it will be done
2438		 * when 2nd devres fires up.
2439		 */
2440	} else {
2441		__input_unregister_device(dev);
2442		input_put_device(dev);
2443	}
2444}
2445EXPORT_SYMBOL(input_unregister_device);
2446
2447/**
2448 * input_register_handler - register a new input handler
2449 * @handler: handler to be registered
2450 *
2451 * This function registers a new input handler (interface) for input
2452 * devices in the system and attaches it to all input devices that
2453 * are compatible with the handler.
2454 */
2455int input_register_handler(struct input_handler *handler)
2456{
2457	struct input_dev *dev;
2458	int error;
2459
2460	error = mutex_lock_interruptible(&input_mutex);
2461	if (error)
2462		return error;
2463
2464	INIT_LIST_HEAD(&handler->h_list);
2465
2466	list_add_tail(&handler->node, &input_handler_list);
2467
2468	list_for_each_entry(dev, &input_dev_list, node)
2469		input_attach_handler(dev, handler);
2470
2471	input_wakeup_procfs_readers();
2472
2473	mutex_unlock(&input_mutex);
2474	return 0;
2475}
2476EXPORT_SYMBOL(input_register_handler);
2477
2478/**
2479 * input_unregister_handler - unregisters an input handler
2480 * @handler: handler to be unregistered
2481 *
2482 * This function disconnects a handler from its input devices and
2483 * removes it from lists of known handlers.
2484 */
2485void input_unregister_handler(struct input_handler *handler)
2486{
2487	struct input_handle *handle, *next;
2488
2489	mutex_lock(&input_mutex);
2490
2491	list_for_each_entry_safe(handle, next, &handler->h_list, h_node)
2492		handler->disconnect(handle);
2493	WARN_ON(!list_empty(&handler->h_list));
2494
2495	list_del_init(&handler->node);
2496
2497	input_wakeup_procfs_readers();
2498
2499	mutex_unlock(&input_mutex);
2500}
2501EXPORT_SYMBOL(input_unregister_handler);
2502
2503/**
2504 * input_handler_for_each_handle - handle iterator
2505 * @handler: input handler to iterate
2506 * @data: data for the callback
2507 * @fn: function to be called for each handle
2508 *
2509 * Iterate over @bus's list of devices, and call @fn for each, passing
2510 * it @data and stop when @fn returns a non-zero value. The function is
2511 * using RCU to traverse the list and therefore may be using in atomic
2512 * contexts. The @fn callback is invoked from RCU critical section and
2513 * thus must not sleep.
2514 */
2515int input_handler_for_each_handle(struct input_handler *handler, void *data,
2516				  int (*fn)(struct input_handle *, void *))
2517{
2518	struct input_handle *handle;
2519	int retval = 0;
2520
2521	rcu_read_lock();
2522
2523	list_for_each_entry_rcu(handle, &handler->h_list, h_node) {
2524		retval = fn(handle, data);
2525		if (retval)
2526			break;
2527	}
2528
2529	rcu_read_unlock();
2530
2531	return retval;
2532}
2533EXPORT_SYMBOL(input_handler_for_each_handle);
2534
2535/**
2536 * input_register_handle - register a new input handle
2537 * @handle: handle to register
2538 *
2539 * This function puts a new input handle onto device's
2540 * and handler's lists so that events can flow through
2541 * it once it is opened using input_open_device().
2542 *
2543 * This function is supposed to be called from handler's
2544 * connect() method.
2545 */
2546int input_register_handle(struct input_handle *handle)
2547{
2548	struct input_handler *handler = handle->handler;
2549	struct input_dev *dev = handle->dev;
2550	int error;
2551
2552	/*
2553	 * We take dev->mutex here to prevent race with
2554	 * input_release_device().
2555	 */
2556	error = mutex_lock_interruptible(&dev->mutex);
2557	if (error)
2558		return error;
2559
2560	/*
2561	 * Filters go to the head of the list, normal handlers
2562	 * to the tail.
2563	 */
2564	if (handler->filter)
2565		list_add_rcu(&handle->d_node, &dev->h_list);
2566	else
2567		list_add_tail_rcu(&handle->d_node, &dev->h_list);
2568
2569	mutex_unlock(&dev->mutex);
2570
2571	/*
2572	 * Since we are supposed to be called from ->connect()
2573	 * which is mutually exclusive with ->disconnect()
2574	 * we can't be racing with input_unregister_handle()
2575	 * and so separate lock is not needed here.
2576	 */
2577	list_add_tail_rcu(&handle->h_node, &handler->h_list);
2578
2579	if (handler->start)
2580		handler->start(handle);
2581
2582	return 0;
2583}
2584EXPORT_SYMBOL(input_register_handle);
2585
2586/**
2587 * input_unregister_handle - unregister an input handle
2588 * @handle: handle to unregister
2589 *
2590 * This function removes input handle from device's
2591 * and handler's lists.
2592 *
2593 * This function is supposed to be called from handler's
2594 * disconnect() method.
2595 */
2596void input_unregister_handle(struct input_handle *handle)
2597{
2598	struct input_dev *dev = handle->dev;
2599
2600	list_del_rcu(&handle->h_node);
2601
2602	/*
2603	 * Take dev->mutex to prevent race with input_release_device().
2604	 */
2605	mutex_lock(&dev->mutex);
2606	list_del_rcu(&handle->d_node);
2607	mutex_unlock(&dev->mutex);
2608
2609	synchronize_rcu();
2610}
2611EXPORT_SYMBOL(input_unregister_handle);
2612
2613/**
2614 * input_get_new_minor - allocates a new input minor number
2615 * @legacy_base: beginning or the legacy range to be searched
2616 * @legacy_num: size of legacy range
2617 * @allow_dynamic: whether we can also take ID from the dynamic range
2618 *
2619 * This function allocates a new device minor for from input major namespace.
2620 * Caller can request legacy minor by specifying @legacy_base and @legacy_num
2621 * parameters and whether ID can be allocated from dynamic range if there are
2622 * no free IDs in legacy range.
2623 */
2624int input_get_new_minor(int legacy_base, unsigned int legacy_num,
2625			bool allow_dynamic)
2626{
2627	/*
2628	 * This function should be called from input handler's ->connect()
2629	 * methods, which are serialized with input_mutex, so no additional
2630	 * locking is needed here.
2631	 */
2632	if (legacy_base >= 0) {
2633		int minor = ida_simple_get(&input_ida,
2634					   legacy_base,
2635					   legacy_base + legacy_num,
2636					   GFP_KERNEL);
2637		if (minor >= 0 || !allow_dynamic)
2638			return minor;
2639	}
2640
2641	return ida_simple_get(&input_ida,
2642			      INPUT_FIRST_DYNAMIC_DEV, INPUT_MAX_CHAR_DEVICES,
2643			      GFP_KERNEL);
2644}
2645EXPORT_SYMBOL(input_get_new_minor);
2646
2647/**
2648 * input_free_minor - release previously allocated minor
2649 * @minor: minor to be released
2650 *
2651 * This function releases previously allocated input minor so that it can be
2652 * reused later.
2653 */
2654void input_free_minor(unsigned int minor)
2655{
2656	ida_simple_remove(&input_ida, minor);
2657}
2658EXPORT_SYMBOL(input_free_minor);
2659
2660static int __init input_init(void)
2661{
2662	int err;
2663
2664	err = class_register(&input_class);
2665	if (err) {
2666		pr_err("unable to register input_dev class\n");
2667		return err;
2668	}
2669
2670	err = input_proc_init();
2671	if (err)
2672		goto fail1;
2673
2674	err = register_chrdev_region(MKDEV(INPUT_MAJOR, 0),
2675				     INPUT_MAX_CHAR_DEVICES, "input");
2676	if (err) {
2677		pr_err("unable to register char major %d", INPUT_MAJOR);
2678		goto fail2;
2679	}
2680
2681	return 0;
2682
2683 fail2:	input_proc_exit();
2684 fail1:	class_unregister(&input_class);
2685	return err;
2686}
2687
2688static void __exit input_exit(void)
2689{
2690	input_proc_exit();
2691	unregister_chrdev_region(MKDEV(INPUT_MAJOR, 0),
2692				 INPUT_MAX_CHAR_DEVICES);
2693	class_unregister(&input_class);
2694}
2695
2696subsys_initcall(input_init);
2697module_exit(input_exit);