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