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