input.c

   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/export.h>
  12#include <linux/init.h>
  13#include <linux/types.h>
  14#include <linux/idr.h>
  15#include <linux/input/mt.h>
  16#include <linux/module.h>
  17#include <linux/slab.h>
  18#include <linux/random.h>
  19#include <linux/major.h>
  20#include <linux/proc_fs.h>
  21#include <linux/sched.h>
  22#include <linux/seq_file.h>
  23#include <linux/pm.h>
  24#include <linux/poll.h>
  25#include <linux/device.h>
  26#include <linux/kstrtox.h>
  27#include <linux/mutex.h>
  28#include <linux/rcupdate.h>
  29#include "input-compat.h"
  30#include "input-core-private.h"
  31#include "input-poller.h"
  32
  33MODULE_AUTHOR("Vojtech Pavlik <vojtech@suse.cz>");
  34MODULE_DESCRIPTION("Input core");
  35MODULE_LICENSE("GPL");
  36
  37#define INPUT_MAX_CHAR_DEVICES		1024
  38#define INPUT_FIRST_DYNAMIC_DEV		256
  39static DEFINE_IDA(input_ida);
  40
  41static LIST_HEAD(input_dev_list);
  42static LIST_HEAD(input_handler_list);
  43
  44/*
  45 * input_mutex protects access to both input_dev_list and input_handler_list.
  46 * This also causes input_[un]register_device and input_[un]register_handler
  47 * be mutually exclusive which simplifies locking in drivers implementing
  48 * input handlers.
  49 */
  50static DEFINE_MUTEX(input_mutex);
  51
  52static const struct input_value input_value_sync = { EV_SYN, SYN_REPORT, 1 };
  53
  54static const unsigned int input_max_code[EV_CNT] = {
  55	[EV_KEY] = KEY_MAX,
  56	[EV_REL] = REL_MAX,
  57	[EV_ABS] = ABS_MAX,
  58	[EV_MSC] = MSC_MAX,
  59	[EV_SW] = SW_MAX,
  60	[EV_LED] = LED_MAX,
  61	[EV_SND] = SND_MAX,
  62	[EV_FF] = FF_MAX,
  63};
  64
  65static inline int is_event_supported(unsigned int code,
  66				     unsigned long *bm, unsigned int max)
  67{
  68	return code <= max && test_bit(code, bm);
  69}
  70
  71static int input_defuzz_abs_event(int value, int old_val, int fuzz)
  72{
  73	if (fuzz) {
  74		if (value > old_val - fuzz / 2 && value < old_val + fuzz / 2)
  75			return old_val;
  76
  77		if (value > old_val - fuzz && value < old_val + fuzz)
  78			return (old_val * 3 + value) / 4;
  79
  80		if (value > old_val - fuzz * 2 && value < old_val + fuzz * 2)
  81			return (old_val + value) / 2;
  82	}
  83
  84	return value;
  85}
  86
  87static void input_start_autorepeat(struct input_dev *dev, int code)
  88{
  89	if (test_bit(EV_REP, dev->evbit) &&
  90	    dev->rep[REP_PERIOD] && dev->rep[REP_DELAY] &&
  91	    dev->timer.function) {
  92		dev->repeat_key = code;
  93		mod_timer(&dev->timer,
  94			  jiffies + msecs_to_jiffies(dev->rep[REP_DELAY]));
  95	}
  96}
  97
  98static void input_stop_autorepeat(struct input_dev *dev)
  99{
 100	timer_delete(&dev->timer);
 101}
 102
 103/*
 104 * Pass values first through all filters and then, if event has not been
 105 * filtered out, through all open handles. This order is achieved by placing
 106 * filters at the head of the list of handles attached to the device, and
 107 * placing regular handles at the tail of the list.
 108 *
 109 * This function is called with dev->event_lock held and interrupts disabled.
 110 */
 111static void input_pass_values(struct input_dev *dev,
 112			      struct input_value *vals, unsigned int count)
 113{
 114	struct input_handle *handle;
 115	struct input_value *v;
 116
 117	lockdep_assert_held(&dev->event_lock);
 118
 119	scoped_guard(rcu) {
 120		handle = rcu_dereference(dev->grab);
 121		if (handle) {
 122			count = handle->handle_events(handle, vals, count);
 123			break;
 124		}
 125
 126		list_for_each_entry_rcu(handle, &dev->h_list, d_node) {
 127			if (handle->open) {
 128				count = handle->handle_events(handle, vals,
 129							      count);
 130				if (!count)
 131					break;
 132			}
 133		}
 134	}
 135
 136	/* trigger auto repeat for key events */
 137	if (test_bit(EV_REP, dev->evbit) && test_bit(EV_KEY, dev->evbit)) {
 138		for (v = vals; v != vals + count; v++) {
 139			if (v->type == EV_KEY && v->value != 2) {
 140				if (v->value)
 141					input_start_autorepeat(dev, v->code);
 142				else
 143					input_stop_autorepeat(dev);
 144			}
 145		}
 146	}
 147}
 148
 149#define INPUT_IGNORE_EVENT	0
 150#define INPUT_PASS_TO_HANDLERS	1
 151#define INPUT_PASS_TO_DEVICE	2
 152#define INPUT_SLOT		4
 153#define INPUT_FLUSH		8
 154#define INPUT_PASS_TO_ALL	(INPUT_PASS_TO_HANDLERS | INPUT_PASS_TO_DEVICE)
 155
 156static int input_handle_abs_event(struct input_dev *dev,
 157				  unsigned int code, int *pval)
 158{
 159	struct input_mt *mt = dev->mt;
 160	bool is_new_slot = false;
 161	bool is_mt_event;
 162	int *pold;
 163
 164	if (code == ABS_MT_SLOT) {
 165		/*
 166		 * "Stage" the event; we'll flush it later, when we
 167		 * get actual touch data.
 168		 */
 169		if (mt && *pval >= 0 && *pval < mt->num_slots)
 170			mt->slot = *pval;
 171
 172		return INPUT_IGNORE_EVENT;
 173	}
 174
 175	is_mt_event = input_is_mt_value(code);
 176
 177	if (!is_mt_event) {
 178		pold = &dev->absinfo[code].value;
 179	} else if (mt) {
 180		pold = &mt->slots[mt->slot].abs[code - ABS_MT_FIRST];
 181		is_new_slot = mt->slot != dev->absinfo[ABS_MT_SLOT].value;
 182	} else {
 183		/*
 184		 * Bypass filtering for multi-touch events when
 185		 * not employing slots.
 186		 */
 187		pold = NULL;
 188	}
 189
 190	if (pold) {
 191		*pval = input_defuzz_abs_event(*pval, *pold,
 192						dev->absinfo[code].fuzz);
 193		if (*pold == *pval)
 194			return INPUT_IGNORE_EVENT;
 195
 196		*pold = *pval;
 197	}
 198
 199	/* Flush pending "slot" event */
 200	if (is_new_slot) {
 201		dev->absinfo[ABS_MT_SLOT].value = mt->slot;
 202		return INPUT_PASS_TO_HANDLERS | INPUT_SLOT;
 203	}
 204
 205	return INPUT_PASS_TO_HANDLERS;
 206}
 207
 208static int input_get_disposition(struct input_dev *dev,
 209			  unsigned int type, unsigned int code, int *pval)
 210{
 211	int disposition = INPUT_IGNORE_EVENT;
 212	int value = *pval;
 213
 214	/* filter-out events from inhibited devices */
 215	if (dev->inhibited)
 216		return INPUT_IGNORE_EVENT;
 217
 218	switch (type) {
 219
 220	case EV_SYN:
 221		switch (code) {
 222		case SYN_CONFIG:
 223			disposition = INPUT_PASS_TO_ALL;
 224			break;
 225
 226		case SYN_REPORT:
 227			disposition = INPUT_PASS_TO_HANDLERS | INPUT_FLUSH;
 228			break;
 229		case SYN_MT_REPORT:
 230			disposition = INPUT_PASS_TO_HANDLERS;
 231			break;
 232		}
 233		break;
 234
 235	case EV_KEY:
 236		if (is_event_supported(code, dev->keybit, KEY_MAX)) {
 237
 238			/* auto-repeat bypasses state updates */
 239			if (value == 2) {
 240				disposition = INPUT_PASS_TO_HANDLERS;
 241				break;
 242			}
 243
 244			if (!!test_bit(code, dev->key) != !!value) {
 245
 246				__change_bit(code, dev->key);
 247				disposition = INPUT_PASS_TO_HANDLERS;
 248			}
 249		}
 250		break;
 251
 252	case EV_SW:
 253		if (is_event_supported(code, dev->swbit, SW_MAX) &&
 254		    !!test_bit(code, dev->sw) != !!value) {
 255
 256			__change_bit(code, dev->sw);
 257			disposition = INPUT_PASS_TO_HANDLERS;
 258		}
 259		break;
 260
 261	case EV_ABS:
 262		if (is_event_supported(code, dev->absbit, ABS_MAX))
 263			disposition = input_handle_abs_event(dev, code, &value);
 264
 265		break;
 266
 267	case EV_REL:
 268		if (is_event_supported(code, dev->relbit, REL_MAX) && value)
 269			disposition = INPUT_PASS_TO_HANDLERS;
 270
 271		break;
 272
 273	case EV_MSC:
 274		if (is_event_supported(code, dev->mscbit, MSC_MAX))
 275			disposition = INPUT_PASS_TO_ALL;
 276
 277		break;
 278
 279	case EV_LED:
 280		if (is_event_supported(code, dev->ledbit, LED_MAX) &&
 281		    !!test_bit(code, dev->led) != !!value) {
 282
 283			__change_bit(code, dev->led);
 284			disposition = INPUT_PASS_TO_ALL;
 285		}
 286		break;
 287
 288	case EV_SND:
 289		if (is_event_supported(code, dev->sndbit, SND_MAX)) {
 290
 291			if (!!test_bit(code, dev->snd) != !!value)
 292				__change_bit(code, dev->snd);
 293			disposition = INPUT_PASS_TO_ALL;
 294		}
 295		break;
 296
 297	case EV_REP:
 298		if (code <= REP_MAX && value >= 0 && dev->rep[code] != value) {
 299			dev->rep[code] = value;
 300			disposition = INPUT_PASS_TO_ALL;
 301		}
 302		break;
 303
 304	case EV_FF:
 305		if (value >= 0)
 306			disposition = INPUT_PASS_TO_ALL;
 307		break;
 308
 309	case EV_PWR:
 310		disposition = INPUT_PASS_TO_ALL;
 311		break;
 312	}
 313
 314	*pval = value;
 315	return disposition;
 316}
 317
 318static void input_event_dispose(struct input_dev *dev, int disposition,
 319				unsigned int type, unsigned int code, int value)
 320{
 321	if ((disposition & INPUT_PASS_TO_DEVICE) && dev->event)
 322		dev->event(dev, type, code, value);
 323
 324	if (disposition & INPUT_PASS_TO_HANDLERS) {
 325		struct input_value *v;
 326
 327		if (disposition & INPUT_SLOT) {
 328			v = &dev->vals[dev->num_vals++];
 329			v->type = EV_ABS;
 330			v->code = ABS_MT_SLOT;
 331			v->value = dev->mt->slot;
 332		}
 333
 334		v = &dev->vals[dev->num_vals++];
 335		v->type = type;
 336		v->code = code;
 337		v->value = value;
 338	}
 339
 340	if (disposition & INPUT_FLUSH) {
 341		if (dev->num_vals >= 2)
 342			input_pass_values(dev, dev->vals, dev->num_vals);
 343		dev->num_vals = 0;
 344		/*
 345		 * Reset the timestamp on flush so we won't end up
 346		 * with a stale one. Note we only need to reset the
 347		 * monolithic one as we use its presence when deciding
 348		 * whether to generate a synthetic timestamp.
 349		 */
 350		dev->timestamp[INPUT_CLK_MONO] = ktime_set(0, 0);
 351	} else if (dev->num_vals >= dev->max_vals - 2) {
 352		dev->vals[dev->num_vals++] = input_value_sync;
 353		input_pass_values(dev, dev->vals, dev->num_vals);
 354		dev->num_vals = 0;
 355	}
 356}
 357
 358void input_handle_event(struct input_dev *dev,
 359			unsigned int type, unsigned int code, int value)
 360{
 361	int disposition;
 362
 363	lockdep_assert_held(&dev->event_lock);
 364
 365	disposition = input_get_disposition(dev, type, code, &value);
 366	if (disposition != INPUT_IGNORE_EVENT) {
 367		if (type != EV_SYN)
 368			add_input_randomness(type, code, value);
 369
 370		input_event_dispose(dev, disposition, type, code, value);
 371	}
 372}
 373
 374/**
 375 * input_event() - report new input event
 376 * @dev: device that generated the event
 377 * @type: type of the event
 378 * @code: event code
 379 * @value: value of the event
 380 *
 381 * This function should be used by drivers implementing various input
 382 * devices to report input events. See also input_inject_event().
 383 *
 384 * NOTE: input_event() may be safely used right after input device was
 385 * allocated with input_allocate_device(), even before it is registered
 386 * with input_register_device(), but the event will not reach any of the
 387 * input handlers. Such early invocation of input_event() may be used
 388 * to 'seed' initial state of a switch or initial position of absolute
 389 * axis, etc.
 390 */
 391void input_event(struct input_dev *dev,
 392		 unsigned int type, unsigned int code, int value)
 393{
 394	if (is_event_supported(type, dev->evbit, EV_MAX)) {
 395		guard(spinlock_irqsave)(&dev->event_lock);
 396		input_handle_event(dev, type, code, value);
 397	}
 398}
 399EXPORT_SYMBOL(input_event);
 400
 401/**
 402 * input_inject_event() - send input event from input handler
 403 * @handle: input handle to send event through
 404 * @type: type of the event
 405 * @code: event code
 406 * @value: value of the event
 407 *
 408 * Similar to input_event() but will ignore event if device is
 409 * "grabbed" and handle injecting event is not the one that owns
 410 * the device.
 411 */
 412void input_inject_event(struct input_handle *handle,
 413			unsigned int type, unsigned int code, int value)
 414{
 415	struct input_dev *dev = handle->dev;
 416	struct input_handle *grab;
 417
 418	if (is_event_supported(type, dev->evbit, EV_MAX)) {
 419		guard(spinlock_irqsave)(&dev->event_lock);
 420		guard(rcu)();
 421
 422		grab = rcu_dereference(dev->grab);
 423		if (!grab || grab == handle)
 424			input_handle_event(dev, type, code, value);
 425
 426	}
 427}
 428EXPORT_SYMBOL(input_inject_event);
 429
 430/**
 431 * input_alloc_absinfo - allocates array of input_absinfo structs
 432 * @dev: the input device emitting absolute events
 433 *
 434 * If the absinfo struct the caller asked for is already allocated, this
 435 * functions will not do anything.
 436 */
 437void input_alloc_absinfo(struct input_dev *dev)
 438{
 439	if (dev->absinfo)
 440		return;
 441
 442	dev->absinfo = kcalloc(ABS_CNT, sizeof(*dev->absinfo), GFP_KERNEL);
 443	if (!dev->absinfo) {
 444		dev_err(dev->dev.parent ?: &dev->dev,
 445			"%s: unable to allocate memory\n", __func__);
 446		/*
 447		 * We will handle this allocation failure in
 448		 * input_register_device() when we refuse to register input
 449		 * device with ABS bits but without absinfo.
 450		 */
 451	}
 452}
 453EXPORT_SYMBOL(input_alloc_absinfo);
 454
 455void input_set_abs_params(struct input_dev *dev, unsigned int axis,
 456			  int min, int max, int fuzz, int flat)
 457{
 458	struct input_absinfo *absinfo;
 459
 460	__set_bit(EV_ABS, dev->evbit);
 461	__set_bit(axis, dev->absbit);
 462
 463	input_alloc_absinfo(dev);
 464	if (!dev->absinfo)
 465		return;
 466
 467	absinfo = &dev->absinfo[axis];
 468	absinfo->minimum = min;
 469	absinfo->maximum = max;
 470	absinfo->fuzz = fuzz;
 471	absinfo->flat = flat;
 472}
 473EXPORT_SYMBOL(input_set_abs_params);
 474
 475/**
 476 * input_copy_abs - Copy absinfo from one input_dev to another
 477 * @dst: Destination input device to copy the abs settings to
 478 * @dst_axis: ABS_* value selecting the destination axis
 479 * @src: Source input device to copy the abs settings from
 480 * @src_axis: ABS_* value selecting the source axis
 481 *
 482 * Set absinfo for the selected destination axis by copying it from
 483 * the specified source input device's source axis.
 484 * This is useful to e.g. setup a pen/stylus input-device for combined
 485 * touchscreen/pen hardware where the pen uses the same coordinates as
 486 * the touchscreen.
 487 */
 488void input_copy_abs(struct input_dev *dst, unsigned int dst_axis,
 489		    const struct input_dev *src, unsigned int src_axis)
 490{
 491	/* src must have EV_ABS and src_axis set */
 492	if (WARN_ON(!(test_bit(EV_ABS, src->evbit) &&
 493		      test_bit(src_axis, src->absbit))))
 494		return;
 495
 496	/*
 497	 * input_alloc_absinfo() may have failed for the source. Our caller is
 498	 * expected to catch this when registering the input devices, which may
 499	 * happen after the input_copy_abs() call.
 500	 */
 501	if (!src->absinfo)
 502		return;
 503
 504	input_set_capability(dst, EV_ABS, dst_axis);
 505	if (!dst->absinfo)
 506		return;
 507
 508	dst->absinfo[dst_axis] = src->absinfo[src_axis];
 509}
 510EXPORT_SYMBOL(input_copy_abs);
 511
 512/**
 513 * input_grab_device - grabs device for exclusive use
 514 * @handle: input handle that wants to own the device
 515 *
 516 * When a device is grabbed by an input handle all events generated by
 517 * the device are delivered only to this handle. Also events injected
 518 * by other input handles are ignored while device is grabbed.
 519 */
 520int input_grab_device(struct input_handle *handle)
 521{
 522	struct input_dev *dev = handle->dev;
 523
 524	scoped_cond_guard(mutex_intr, return -EINTR, &dev->mutex) {
 525		if (dev->grab)
 526			return -EBUSY;
 527
 528		rcu_assign_pointer(dev->grab, handle);
 529	}
 530
 531	return 0;
 532}
 533EXPORT_SYMBOL(input_grab_device);
 534
 535static void __input_release_device(struct input_handle *handle)
 536{
 537	struct input_dev *dev = handle->dev;
 538	struct input_handle *grabber;
 539
 540	grabber = rcu_dereference_protected(dev->grab,
 541					    lockdep_is_held(&dev->mutex));
 542	if (grabber == handle) {
 543		rcu_assign_pointer(dev->grab, NULL);
 544		/* Make sure input_pass_values() notices that grab is gone */
 545		synchronize_rcu();
 546
 547		list_for_each_entry(handle, &dev->h_list, d_node)
 548			if (handle->open && handle->handler->start)
 549				handle->handler->start(handle);
 550	}
 551}
 552
 553/**
 554 * input_release_device - release previously grabbed device
 555 * @handle: input handle that owns the device
 556 *
 557 * Releases previously grabbed device so that other input handles can
 558 * start receiving input events. Upon release all handlers attached
 559 * to the device have their start() method called so they have a change
 560 * to synchronize device state with the rest of the system.
 561 */
 562void input_release_device(struct input_handle *handle)
 563{
 564	struct input_dev *dev = handle->dev;
 565
 566	guard(mutex)(&dev->mutex);
 567	__input_release_device(handle);
 568}
 569EXPORT_SYMBOL(input_release_device);
 570
 571/**
 572 * input_open_device - open input device
 573 * @handle: handle through which device is being accessed
 574 *
 575 * This function should be called by input handlers when they
 576 * want to start receive events from given input device.
 577 */
 578int input_open_device(struct input_handle *handle)
 579{
 580	struct input_dev *dev = handle->dev;
 581	int error;
 582
 583	scoped_cond_guard(mutex_intr, return -EINTR, &dev->mutex) {
 584		if (dev->going_away)
 585			return -ENODEV;
 586
 587		handle->open++;
 588
 589		if (handle->handler->passive_observer)
 590			return 0;
 591
 592		if (dev->users++ || dev->inhibited) {
 593			/*
 594			 * Device is already opened and/or inhibited,
 595			 * so we can exit immediately and report success.
 596			 */
 597			return 0;
 598		}
 599
 600		if (dev->open) {
 601			error = dev->open(dev);
 602			if (error) {
 603				dev->users--;
 604				handle->open--;
 605				/*
 606				 * Make sure we are not delivering any more
 607				 * events through this handle.
 608				 */
 609				synchronize_rcu();
 610				return error;
 611			}
 612		}
 613
 614		if (dev->poller)
 615			input_dev_poller_start(dev->poller);
 616	}
 617
 618	return 0;
 619}
 620EXPORT_SYMBOL(input_open_device);
 621
 622int input_flush_device(struct input_handle *handle, struct file *file)
 623{
 624	struct input_dev *dev = handle->dev;
 625
 626	scoped_cond_guard(mutex_intr, return -EINTR, &dev->mutex) {
 627		if (dev->flush)
 628			return dev->flush(dev, file);
 629	}
 630
 631	return 0;
 632}
 633EXPORT_SYMBOL(input_flush_device);
 634
 635/**
 636 * input_close_device - close input device
 637 * @handle: handle through which device is being accessed
 638 *
 639 * This function should be called by input handlers when they
 640 * want to stop receive events from given input device.
 641 */
 642void input_close_device(struct input_handle *handle)
 643{
 644	struct input_dev *dev = handle->dev;
 645
 646	guard(mutex)(&dev->mutex);
 647
 648	__input_release_device(handle);
 649
 650	if (!handle->handler->passive_observer) {
 651		if (!--dev->users && !dev->inhibited) {
 652			if (dev->poller)
 653				input_dev_poller_stop(dev->poller);
 654			if (dev->close)
 655				dev->close(dev);
 656		}
 657	}
 658
 659	if (!--handle->open) {
 660		/*
 661		 * synchronize_rcu() makes sure that input_pass_values()
 662		 * completed and that no more input events are delivered
 663		 * through this handle
 664		 */
 665		synchronize_rcu();
 666	}
 667}
 668EXPORT_SYMBOL(input_close_device);
 669
 670/*
 671 * Simulate keyup events for all keys that are marked as pressed.
 672 * The function must be called with dev->event_lock held.
 673 */
 674static bool input_dev_release_keys(struct input_dev *dev)
 675{
 676	bool need_sync = false;
 677	int code;
 678
 679	lockdep_assert_held(&dev->event_lock);
 680
 681	if (is_event_supported(EV_KEY, dev->evbit, EV_MAX)) {
 682		for_each_set_bit(code, dev->key, KEY_CNT) {
 683			input_handle_event(dev, EV_KEY, code, 0);
 684			need_sync = true;
 685		}
 686	}
 687
 688	return need_sync;
 689}
 690
 691/*
 692 * Prepare device for unregistering
 693 */
 694static void input_disconnect_device(struct input_dev *dev)
 695{
 696	struct input_handle *handle;
 697
 698	/*
 699	 * Mark device as going away. Note that we take dev->mutex here
 700	 * not to protect access to dev->going_away but rather to ensure
 701	 * that there are no threads in the middle of input_open_device()
 702	 */
 703	scoped_guard(mutex, &dev->mutex)
 704		dev->going_away = true;
 705
 706	guard(spinlock_irq)(&dev->event_lock);
 707
 708	/*
 709	 * Simulate keyup events for all pressed keys so that handlers
 710	 * are not left with "stuck" keys. The driver may continue
 711	 * generate events even after we done here but they will not
 712	 * reach any handlers.
 713	 */
 714	if (input_dev_release_keys(dev))
 715		input_handle_event(dev, EV_SYN, SYN_REPORT, 1);
 716
 717	list_for_each_entry(handle, &dev->h_list, d_node)
 718		handle->open = 0;
 719}
 720
 721/**
 722 * input_scancode_to_scalar() - converts scancode in &struct input_keymap_entry
 723 * @ke: keymap entry containing scancode to be converted.
 724 * @scancode: pointer to the location where converted scancode should
 725 *	be stored.
 726 *
 727 * This function is used to convert scancode stored in &struct keymap_entry
 728 * into scalar form understood by legacy keymap handling methods. These
 729 * methods expect scancodes to be represented as 'unsigned int'.
 730 */
 731int input_scancode_to_scalar(const struct input_keymap_entry *ke,
 732			     unsigned int *scancode)
 733{
 734	switch (ke->len) {
 735	case 1:
 736		*scancode = *((u8 *)ke->scancode);
 737		break;
 738
 739	case 2:
 740		*scancode = *((u16 *)ke->scancode);
 741		break;
 742
 743	case 4:
 744		*scancode = *((u32 *)ke->scancode);
 745		break;
 746
 747	default:
 748		return -EINVAL;
 749	}
 750
 751	return 0;
 752}
 753EXPORT_SYMBOL(input_scancode_to_scalar);
 754
 755/*
 756 * Those routines handle the default case where no [gs]etkeycode() is
 757 * defined. In this case, an array indexed by the scancode is used.
 758 */
 759
 760static unsigned int input_fetch_keycode(struct input_dev *dev,
 761					unsigned int index)
 762{
 763	switch (dev->keycodesize) {
 764	case 1:
 765		return ((u8 *)dev->keycode)[index];
 766
 767	case 2:
 768		return ((u16 *)dev->keycode)[index];
 769
 770	default:
 771		return ((u32 *)dev->keycode)[index];
 772	}
 773}
 774
 775static int input_default_getkeycode(struct input_dev *dev,
 776				    struct input_keymap_entry *ke)
 777{
 778	unsigned int index;
 779	int error;
 780
 781	if (!dev->keycodesize)
 782		return -EINVAL;
 783
 784	if (ke->flags & INPUT_KEYMAP_BY_INDEX)
 785		index = ke->index;
 786	else {
 787		error = input_scancode_to_scalar(ke, &index);
 788		if (error)
 789			return error;
 790	}
 791
 792	if (index >= dev->keycodemax)
 793		return -EINVAL;
 794
 795	ke->keycode = input_fetch_keycode(dev, index);
 796	ke->index = index;
 797	ke->len = sizeof(index);
 798	memcpy(ke->scancode, &index, sizeof(index));
 799
 800	return 0;
 801}
 802
 803static int input_default_setkeycode(struct input_dev *dev,
 804				    const struct input_keymap_entry *ke,
 805				    unsigned int *old_keycode)
 806{
 807	unsigned int index;
 808	int error;
 809	int i;
 810
 811	if (!dev->keycodesize)
 812		return -EINVAL;
 813
 814	if (ke->flags & INPUT_KEYMAP_BY_INDEX) {
 815		index = ke->index;
 816	} else {
 817		error = input_scancode_to_scalar(ke, &index);
 818		if (error)
 819			return error;
 820	}
 821
 822	if (index >= dev->keycodemax)
 823		return -EINVAL;
 824
 825	if (dev->keycodesize < sizeof(ke->keycode) &&
 826			(ke->keycode >> (dev->keycodesize * 8)))
 827		return -EINVAL;
 828
 829	switch (dev->keycodesize) {
 830		case 1: {
 831			u8 *k = (u8 *)dev->keycode;
 832			*old_keycode = k[index];
 833			k[index] = ke->keycode;
 834			break;
 835		}
 836		case 2: {
 837			u16 *k = (u16 *)dev->keycode;
 838			*old_keycode = k[index];
 839			k[index] = ke->keycode;
 840			break;
 841		}
 842		default: {
 843			u32 *k = (u32 *)dev->keycode;
 844			*old_keycode = k[index];
 845			k[index] = ke->keycode;
 846			break;
 847		}
 848	}
 849
 850	if (*old_keycode <= KEY_MAX) {
 851		__clear_bit(*old_keycode, dev->keybit);
 852		for (i = 0; i < dev->keycodemax; i++) {
 853			if (input_fetch_keycode(dev, i) == *old_keycode) {
 854				__set_bit(*old_keycode, dev->keybit);
 855				/* Setting the bit twice is useless, so break */
 856				break;
 857			}
 858		}
 859	}
 860
 861	__set_bit(ke->keycode, dev->keybit);
 862	return 0;
 863}
 864
 865/**
 866 * input_get_keycode - retrieve keycode currently mapped to a given scancode
 867 * @dev: input device which keymap is being queried
 868 * @ke: keymap entry
 869 *
 870 * This function should be called by anyone interested in retrieving current
 871 * keymap. Presently evdev handlers use it.
 872 */
 873int input_get_keycode(struct input_dev *dev, struct input_keymap_entry *ke)
 874{
 875	guard(spinlock_irqsave)(&dev->event_lock);
 876
 877	return dev->getkeycode(dev, ke);
 878}
 879EXPORT_SYMBOL(input_get_keycode);
 880
 881/**
 882 * input_set_keycode - attribute a keycode to a given scancode
 883 * @dev: input device which keymap is being updated
 884 * @ke: new keymap entry
 885 *
 886 * This function should be called by anyone needing to update current
 887 * keymap. Presently keyboard and evdev handlers use it.
 888 */
 889int input_set_keycode(struct input_dev *dev,
 890		      const struct input_keymap_entry *ke)
 891{
 892	unsigned int old_keycode;
 893	int error;
 894
 895	if (ke->keycode > KEY_MAX)
 896		return -EINVAL;
 897
 898	guard(spinlock_irqsave)(&dev->event_lock);
 899
 900	error = dev->setkeycode(dev, ke, &old_keycode);
 901	if (error)
 902		return error;
 903
 904	/* Make sure KEY_RESERVED did not get enabled. */
 905	__clear_bit(KEY_RESERVED, dev->keybit);
 906
 907	/*
 908	 * Simulate keyup event if keycode is not present
 909	 * in the keymap anymore
 910	 */
 911	if (old_keycode > KEY_MAX) {
 912		dev_warn(dev->dev.parent ?: &dev->dev,
 913			 "%s: got too big old keycode %#x\n",
 914			 __func__, old_keycode);
 915	} else if (test_bit(EV_KEY, dev->evbit) &&
 916		   !is_event_supported(old_keycode, dev->keybit, KEY_MAX) &&
 917		   __test_and_clear_bit(old_keycode, dev->key)) {
 918		/*
 919		 * We have to use input_event_dispose() here directly instead
 920		 * of input_handle_event() because the key we want to release
 921		 * here is considered no longer supported by the device and
 922		 * input_handle_event() will ignore it.
 923		 */
 924		input_event_dispose(dev, INPUT_PASS_TO_HANDLERS,
 925				    EV_KEY, old_keycode, 0);
 926		input_event_dispose(dev, INPUT_PASS_TO_HANDLERS | INPUT_FLUSH,
 927				    EV_SYN, SYN_REPORT, 1);
 928	}
 929
 930	return 0;
 931}
 932EXPORT_SYMBOL(input_set_keycode);
 933
 934bool input_match_device_id(const struct input_dev *dev,
 935			   const struct input_device_id *id)
 936{
 937	if (id->flags & INPUT_DEVICE_ID_MATCH_BUS)
 938		if (id->bustype != dev->id.bustype)
 939			return false;
 940
 941	if (id->flags & INPUT_DEVICE_ID_MATCH_VENDOR)
 942		if (id->vendor != dev->id.vendor)
 943			return false;
 944
 945	if (id->flags & INPUT_DEVICE_ID_MATCH_PRODUCT)
 946		if (id->product != dev->id.product)
 947			return false;
 948
 949	if (id->flags & INPUT_DEVICE_ID_MATCH_VERSION)
 950		if (id->version != dev->id.version)
 951			return false;
 952
 953	if (!bitmap_subset(id->evbit, dev->evbit, EV_MAX) ||
 954	    !bitmap_subset(id->keybit, dev->keybit, KEY_MAX) ||
 955	    !bitmap_subset(id->relbit, dev->relbit, REL_MAX) ||
 956	    !bitmap_subset(id->absbit, dev->absbit, ABS_MAX) ||
 957	    !bitmap_subset(id->mscbit, dev->mscbit, MSC_MAX) ||
 958	    !bitmap_subset(id->ledbit, dev->ledbit, LED_MAX) ||
 959	    !bitmap_subset(id->sndbit, dev->sndbit, SND_MAX) ||
 960	    !bitmap_subset(id->ffbit, dev->ffbit, FF_MAX) ||
 961	    !bitmap_subset(id->swbit, dev->swbit, SW_MAX) ||
 962	    !bitmap_subset(id->propbit, dev->propbit, INPUT_PROP_MAX)) {
 963		return false;
 964	}
 965
 966	return true;
 967}
 968EXPORT_SYMBOL(input_match_device_id);
 969
 970static const struct input_device_id *input_match_device(struct input_handler *handler,
 971							struct input_dev *dev)
 972{
 973	const struct input_device_id *id;
 974
 975	for (id = handler->id_table; id->flags; id++) {
 976		if (input_match_device_id(dev, id) &&
 977		    (!handler->match || handler->match(handler, dev))) {
 978			return id;
 979		}
 980	}
 981
 982	return NULL;
 983}
 984
 985static int input_attach_handler(struct input_dev *dev, struct input_handler *handler)
 986{
 987	const struct input_device_id *id;
 988	int error;
 989
 990	id = input_match_device(handler, dev);
 991	if (!id)
 992		return -ENODEV;
 993
 994	error = handler->connect(handler, dev, id);
 995	if (error && error != -ENODEV)
 996		pr_err("failed to attach handler %s to device %s, error: %d\n",
 997		       handler->name, kobject_name(&dev->dev.kobj), error);
 998
 999	return error;
1000}
1001
1002#ifdef CONFIG_PROC_FS
1003
1004static struct proc_dir_entry *proc_bus_input_dir;
1005static DECLARE_WAIT_QUEUE_HEAD(input_devices_poll_wait);
1006static int input_devices_state;
1007
1008static inline void input_wakeup_procfs_readers(void)
1009{
1010	input_devices_state++;
1011	wake_up(&input_devices_poll_wait);
1012}
1013
1014struct input_seq_state {
1015	unsigned short pos;
1016	bool mutex_acquired;
1017	int input_devices_state;
1018};
1019
1020static __poll_t input_proc_devices_poll(struct file *file, poll_table *wait)
1021{
1022	struct seq_file *seq = file->private_data;
1023	struct input_seq_state *state = seq->private;
1024
1025	poll_wait(file, &input_devices_poll_wait, wait);
1026	if (state->input_devices_state != input_devices_state) {
1027		state->input_devices_state = input_devices_state;
1028		return EPOLLIN | EPOLLRDNORM;
1029	}
1030
1031	return 0;
1032}
1033
1034static void *input_devices_seq_start(struct seq_file *seq, loff_t *pos)
1035{
1036	struct input_seq_state *state = seq->private;
1037	int error;
1038
1039	error = mutex_lock_interruptible(&input_mutex);
1040	if (error) {
1041		state->mutex_acquired = false;
1042		return ERR_PTR(error);
1043	}
1044
1045	state->mutex_acquired = true;
1046
1047	return seq_list_start(&input_dev_list, *pos);
1048}
1049
1050static void *input_devices_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1051{
1052	return seq_list_next(v, &input_dev_list, pos);
1053}
1054
1055static void input_seq_stop(struct seq_file *seq, void *v)
1056{
1057	struct input_seq_state *state = seq->private;
1058
1059	if (state->mutex_acquired)
1060		mutex_unlock(&input_mutex);
1061}
1062
1063static void input_seq_print_bitmap(struct seq_file *seq, const char *name,
1064				   unsigned long *bitmap, int max)
1065{
1066	int i;
1067	bool skip_empty = true;
1068	char buf[18];
1069
1070	seq_printf(seq, "B: %s=", name);
1071
1072	for (i = BITS_TO_LONGS(max) - 1; i >= 0; i--) {
1073		if (input_bits_to_string(buf, sizeof(buf),
1074					 bitmap[i], skip_empty)) {
1075			skip_empty = false;
1076			seq_printf(seq, "%s%s", buf, i > 0 ? " " : "");
1077		}
1078	}
1079
1080	/*
1081	 * If no output was produced print a single 0.
1082	 */
1083	if (skip_empty)
1084		seq_putc(seq, '0');
1085
1086	seq_putc(seq, '\n');
1087}
1088
1089static int input_devices_seq_show(struct seq_file *seq, void *v)
1090{
1091	struct input_dev *dev = container_of(v, struct input_dev, node);
1092	const char *path = kobject_get_path(&dev->dev.kobj, GFP_KERNEL);
1093	struct input_handle *handle;
1094
1095	seq_printf(seq, "I: Bus=%04x Vendor=%04x Product=%04x Version=%04x\n",
1096		   dev->id.bustype, dev->id.vendor, dev->id.product, dev->id.version);
1097
1098	seq_printf(seq, "N: Name=\"%s\"\n", dev->name ? dev->name : "");
1099	seq_printf(seq, "P: Phys=%s\n", dev->phys ? dev->phys : "");
1100	seq_printf(seq, "S: Sysfs=%s\n", path ? path : "");
1101	seq_printf(seq, "U: Uniq=%s\n", dev->uniq ? dev->uniq : "");
1102	seq_puts(seq, "H: Handlers=");
1103
1104	list_for_each_entry(handle, &dev->h_list, d_node)
1105		seq_printf(seq, "%s ", handle->name);
1106	seq_putc(seq, '\n');
1107
1108	input_seq_print_bitmap(seq, "PROP", dev->propbit, INPUT_PROP_MAX);
1109
1110	input_seq_print_bitmap(seq, "EV", dev->evbit, EV_MAX);
1111	if (test_bit(EV_KEY, dev->evbit))
1112		input_seq_print_bitmap(seq, "KEY", dev->keybit, KEY_MAX);
1113	if (test_bit(EV_REL, dev->evbit))
1114		input_seq_print_bitmap(seq, "REL", dev->relbit, REL_MAX);
1115	if (test_bit(EV_ABS, dev->evbit))
1116		input_seq_print_bitmap(seq, "ABS", dev->absbit, ABS_MAX);
1117	if (test_bit(EV_MSC, dev->evbit))
1118		input_seq_print_bitmap(seq, "MSC", dev->mscbit, MSC_MAX);
1119	if (test_bit(EV_LED, dev->evbit))
1120		input_seq_print_bitmap(seq, "LED", dev->ledbit, LED_MAX);
1121	if (test_bit(EV_SND, dev->evbit))
1122		input_seq_print_bitmap(seq, "SND", dev->sndbit, SND_MAX);
1123	if (test_bit(EV_FF, dev->evbit))
1124		input_seq_print_bitmap(seq, "FF", dev->ffbit, FF_MAX);
1125	if (test_bit(EV_SW, dev->evbit))
1126		input_seq_print_bitmap(seq, "SW", dev->swbit, SW_MAX);
1127
1128	seq_putc(seq, '\n');
1129
1130	kfree(path);
1131	return 0;
1132}
1133
1134static const struct seq_operations input_devices_seq_ops = {
1135	.start	= input_devices_seq_start,
1136	.next	= input_devices_seq_next,
1137	.stop	= input_seq_stop,
1138	.show	= input_devices_seq_show,
1139};
1140
1141static int input_proc_devices_open(struct inode *inode, struct file *file)
1142{
1143	return seq_open_private(file, &input_devices_seq_ops,
1144				sizeof(struct input_seq_state));
1145}
1146
1147static const struct proc_ops input_devices_proc_ops = {
1148	.proc_open	= input_proc_devices_open,
1149	.proc_poll	= input_proc_devices_poll,
1150	.proc_read	= seq_read,
1151	.proc_lseek	= seq_lseek,
1152	.proc_release	= seq_release_private,
1153};
1154
1155static void *input_handlers_seq_start(struct seq_file *seq, loff_t *pos)
1156{
1157	struct input_seq_state *state = seq->private;
1158	int error;
1159
1160	error = mutex_lock_interruptible(&input_mutex);
1161	if (error) {
1162		state->mutex_acquired = false;
1163		return ERR_PTR(error);
1164	}
1165
1166	state->mutex_acquired = true;
1167	state->pos = *pos;
1168
1169	return seq_list_start(&input_handler_list, *pos);
1170}
1171
1172static void *input_handlers_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1173{
1174	struct input_seq_state *state = seq->private;
1175
1176	state->pos = *pos + 1;
1177	return seq_list_next(v, &input_handler_list, pos);
1178}
1179
1180static int input_handlers_seq_show(struct seq_file *seq, void *v)
1181{
1182	struct input_handler *handler = container_of(v, struct input_handler, node);
1183	struct input_seq_state *state = seq->private;
1184
1185	seq_printf(seq, "N: Number=%u Name=%s", state->pos, handler->name);
1186	if (handler->filter)
1187		seq_puts(seq, " (filter)");
1188	if (handler->legacy_minors)
1189		seq_printf(seq, " Minor=%d", handler->minor);
1190	seq_putc(seq, '\n');
1191
1192	return 0;
1193}
1194
1195static const struct seq_operations input_handlers_seq_ops = {
1196	.start	= input_handlers_seq_start,
1197	.next	= input_handlers_seq_next,
1198	.stop	= input_seq_stop,
1199	.show	= input_handlers_seq_show,
1200};
1201
1202static int input_proc_handlers_open(struct inode *inode, struct file *file)
1203{
1204	return seq_open_private(file, &input_handlers_seq_ops,
1205				sizeof(struct input_seq_state));
1206}
1207
1208static const struct proc_ops input_handlers_proc_ops = {
1209	.proc_open	= input_proc_handlers_open,
1210	.proc_read	= seq_read,
1211	.proc_lseek	= seq_lseek,
1212	.proc_release	= seq_release_private,
1213};
1214
1215static int __init input_proc_init(void)
1216{
1217	struct proc_dir_entry *entry;
1218
1219	proc_bus_input_dir = proc_mkdir("bus/input", NULL);
1220	if (!proc_bus_input_dir)
1221		return -ENOMEM;
1222
1223	entry = proc_create("devices", 0, proc_bus_input_dir,
1224			    &input_devices_proc_ops);
1225	if (!entry)
1226		goto fail1;
1227
1228	entry = proc_create("handlers", 0, proc_bus_input_dir,
1229			    &input_handlers_proc_ops);
1230	if (!entry)
1231		goto fail2;
1232
1233	return 0;
1234
1235 fail2:	remove_proc_entry("devices", proc_bus_input_dir);
1236 fail1: remove_proc_entry("bus/input", NULL);
1237	return -ENOMEM;
1238}
1239
1240static void input_proc_exit(void)
1241{
1242	remove_proc_entry("devices", proc_bus_input_dir);
1243	remove_proc_entry("handlers", proc_bus_input_dir);
1244	remove_proc_entry("bus/input", NULL);
1245}
1246
1247#else /* !CONFIG_PROC_FS */
1248static inline void input_wakeup_procfs_readers(void) { }
1249static inline int input_proc_init(void) { return 0; }
1250static inline void input_proc_exit(void) { }
1251#endif
1252
1253#define INPUT_DEV_STRING_ATTR_SHOW(name)				\
1254static ssize_t input_dev_show_##name(struct device *dev,		\
1255				     struct device_attribute *attr,	\
1256				     char *buf)				\
1257{									\
1258	struct input_dev *input_dev = to_input_dev(dev);		\
1259									\
1260	return sysfs_emit(buf, "%s\n",					\
1261			  input_dev->name ? input_dev->name : "");	\
1262}									\
1263static DEVICE_ATTR(name, S_IRUGO, input_dev_show_##name, NULL)
1264
1265INPUT_DEV_STRING_ATTR_SHOW(name);
1266INPUT_DEV_STRING_ATTR_SHOW(phys);
1267INPUT_DEV_STRING_ATTR_SHOW(uniq);
1268
1269static int input_print_modalias_bits(char *buf, int size,
1270				     char name, const unsigned long *bm,
1271				     unsigned int min_bit, unsigned int max_bit)
1272{
1273	int bit = min_bit;
1274	int len = 0;
1275
1276	len += snprintf(buf, max(size, 0), "%c", name);
1277	for_each_set_bit_from(bit, bm, max_bit)
1278		len += snprintf(buf + len, max(size - len, 0), "%X,", bit);
1279	return len;
1280}
1281
1282static int input_print_modalias_parts(char *buf, int size, int full_len,
1283				      const struct input_dev *id)
1284{
1285	int len, klen, remainder, space;
1286
1287	len = snprintf(buf, max(size, 0),
1288		       "input:b%04Xv%04Xp%04Xe%04X-",
1289		       id->id.bustype, id->id.vendor,
1290		       id->id.product, id->id.version);
1291
1292	len += input_print_modalias_bits(buf + len, size - len,
1293				'e', id->evbit, 0, EV_MAX);
1294
1295	/*
1296	 * Calculate the remaining space in the buffer making sure we
1297	 * have place for the terminating 0.
1298	 */
1299	space = max(size - (len + 1), 0);
1300
1301	klen = input_print_modalias_bits(buf + len, size - len,
1302				'k', id->keybit, KEY_MIN_INTERESTING, KEY_MAX);
1303	len += klen;
1304
1305	/*
1306	 * If we have more data than we can fit in the buffer, check
1307	 * if we can trim key data to fit in the rest. We will indicate
1308	 * that key data is incomplete by adding "+" sign at the end, like
1309	 * this: * "k1,2,3,45,+,".
1310	 *
1311	 * Note that we shortest key info (if present) is "k+," so we
1312	 * can only try to trim if key data is longer than that.
1313	 */
1314	if (full_len && size < full_len + 1 && klen > 3) {
1315		remainder = full_len - len;
1316		/*
1317		 * We can only trim if we have space for the remainder
1318		 * and also for at least "k+," which is 3 more characters.
1319		 */
1320		if (remainder <= space - 3) {
1321			/*
1322			 * We are guaranteed to have 'k' in the buffer, so
1323			 * we need at least 3 additional bytes for storing
1324			 * "+," in addition to the remainder.
1325			 */
1326			for (int i = size - 1 - remainder - 3; i >= 0; i--) {
1327				if (buf[i] == 'k' || buf[i] == ',') {
1328					strcpy(buf + i + 1, "+,");
1329					len = i + 3; /* Not counting '\0' */
1330					break;
1331				}
1332			}
1333		}
1334	}
1335
1336	len += input_print_modalias_bits(buf + len, size - len,
1337				'r', id->relbit, 0, REL_MAX);
1338	len += input_print_modalias_bits(buf + len, size - len,
1339				'a', id->absbit, 0, ABS_MAX);
1340	len += input_print_modalias_bits(buf + len, size - len,
1341				'm', id->mscbit, 0, MSC_MAX);
1342	len += input_print_modalias_bits(buf + len, size - len,
1343				'l', id->ledbit, 0, LED_MAX);
1344	len += input_print_modalias_bits(buf + len, size - len,
1345				's', id->sndbit, 0, SND_MAX);
1346	len += input_print_modalias_bits(buf + len, size - len,
1347				'f', id->ffbit, 0, FF_MAX);
1348	len += input_print_modalias_bits(buf + len, size - len,
1349				'w', id->swbit, 0, SW_MAX);
1350
1351	return len;
1352}
1353
1354static int input_print_modalias(char *buf, int size, const struct input_dev *id)
1355{
1356	int full_len;
1357
1358	/*
1359	 * Printing is done in 2 passes: first one figures out total length
1360	 * needed for the modalias string, second one will try to trim key
1361	 * data in case when buffer is too small for the entire modalias.
1362	 * If the buffer is too small regardless, it will fill as much as it
1363	 * can (without trimming key data) into the buffer and leave it to
1364	 * the caller to figure out what to do with the result.
1365	 */
1366	full_len = input_print_modalias_parts(NULL, 0, 0, id);
1367	return input_print_modalias_parts(buf, size, full_len, id);
1368}
1369
1370static ssize_t input_dev_show_modalias(struct device *dev,
1371				       struct device_attribute *attr,
1372				       char *buf)
1373{
1374	struct input_dev *id = to_input_dev(dev);
1375	ssize_t len;
1376
1377	len = input_print_modalias(buf, PAGE_SIZE, id);
1378	if (len < PAGE_SIZE - 2)
1379		len += snprintf(buf + len, PAGE_SIZE - len, "\n");
1380
1381	return min_t(int, len, PAGE_SIZE);
1382}
1383static DEVICE_ATTR(modalias, S_IRUGO, input_dev_show_modalias, NULL);
1384
1385static int input_print_bitmap(char *buf, int buf_size, const unsigned long *bitmap,
1386			      int max, int add_cr);
1387
1388static ssize_t input_dev_show_properties(struct device *dev,
1389					 struct device_attribute *attr,
1390					 char *buf)
1391{
1392	struct input_dev *input_dev = to_input_dev(dev);
1393	int len = input_print_bitmap(buf, PAGE_SIZE, input_dev->propbit,
1394				     INPUT_PROP_MAX, true);
1395	return min_t(int, len, PAGE_SIZE);
1396}
1397static DEVICE_ATTR(properties, S_IRUGO, input_dev_show_properties, NULL);
1398
1399static int input_inhibit_device(struct input_dev *dev);
1400static int input_uninhibit_device(struct input_dev *dev);
1401
1402static ssize_t inhibited_show(struct device *dev,
1403			      struct device_attribute *attr,
1404			      char *buf)
1405{
1406	struct input_dev *input_dev = to_input_dev(dev);
1407
1408	return sysfs_emit(buf, "%d\n", input_dev->inhibited);
1409}
1410
1411static ssize_t inhibited_store(struct device *dev,
1412			       struct device_attribute *attr, const char *buf,
1413			       size_t len)
1414{
1415	struct input_dev *input_dev = to_input_dev(dev);
1416	ssize_t rv;
1417	bool inhibited;
1418
1419	if (kstrtobool(buf, &inhibited))
1420		return -EINVAL;
1421
1422	if (inhibited)
1423		rv = input_inhibit_device(input_dev);
1424	else
1425		rv = input_uninhibit_device(input_dev);
1426
1427	if (rv != 0)
1428		return rv;
1429
1430	return len;
1431}
1432
1433static DEVICE_ATTR_RW(inhibited);
1434
1435static struct attribute *input_dev_attrs[] = {
1436	&dev_attr_name.attr,
1437	&dev_attr_phys.attr,
1438	&dev_attr_uniq.attr,
1439	&dev_attr_modalias.attr,
1440	&dev_attr_properties.attr,
1441	&dev_attr_inhibited.attr,
1442	NULL
1443};
1444
1445static const struct attribute_group input_dev_attr_group = {
1446	.attrs	= input_dev_attrs,
1447};
1448
1449#define INPUT_DEV_ID_ATTR(name)						\
1450static ssize_t input_dev_show_id_##name(struct device *dev,		\
1451					struct device_attribute *attr,	\
1452					char *buf)			\
1453{									\
1454	struct input_dev *input_dev = to_input_dev(dev);		\
1455	return sysfs_emit(buf, "%04x\n", input_dev->id.name);		\
1456}									\
1457static DEVICE_ATTR(name, S_IRUGO, input_dev_show_id_##name, NULL)
1458
1459INPUT_DEV_ID_ATTR(bustype);
1460INPUT_DEV_ID_ATTR(vendor);
1461INPUT_DEV_ID_ATTR(product);
1462INPUT_DEV_ID_ATTR(version);
1463
1464static struct attribute *input_dev_id_attrs[] = {
1465	&dev_attr_bustype.attr,
1466	&dev_attr_vendor.attr,
1467	&dev_attr_product.attr,
1468	&dev_attr_version.attr,
1469	NULL
1470};
1471
1472static const struct attribute_group input_dev_id_attr_group = {
1473	.name	= "id",
1474	.attrs	= input_dev_id_attrs,
1475};
1476
1477static int input_print_bitmap(char *buf, int buf_size, const unsigned long *bitmap,
1478			      int max, int add_cr)
1479{
1480	int i;
1481	int len = 0;
1482	bool skip_empty = true;
1483
1484	for (i = BITS_TO_LONGS(max) - 1; i >= 0; i--) {
1485		len += input_bits_to_string(buf + len, max(buf_size - len, 0),
1486					    bitmap[i], skip_empty);
1487		if (len) {
1488			skip_empty = false;
1489			if (i > 0)
1490				len += snprintf(buf + len, max(buf_size - len, 0), " ");
1491		}
1492	}
1493
1494	/*
1495	 * If no output was produced print a single 0.
1496	 */
1497	if (len == 0)
1498		len = snprintf(buf, buf_size, "%d", 0);
1499
1500	if (add_cr)
1501		len += snprintf(buf + len, max(buf_size - len, 0), "\n");
1502
1503	return len;
1504}
1505
1506#define INPUT_DEV_CAP_ATTR(ev, bm)					\
1507static ssize_t input_dev_show_cap_##bm(struct device *dev,		\
1508				       struct device_attribute *attr,	\
1509				       char *buf)			\
1510{									\
1511	struct input_dev *input_dev = to_input_dev(dev);		\
1512	int len = input_print_bitmap(buf, PAGE_SIZE,			\
1513				     input_dev->bm##bit, ev##_MAX,	\
1514				     true);				\
1515	return min_t(int, len, PAGE_SIZE);				\
1516}									\
1517static DEVICE_ATTR(bm, S_IRUGO, input_dev_show_cap_##bm, NULL)
1518
1519INPUT_DEV_CAP_ATTR(EV, ev);
1520INPUT_DEV_CAP_ATTR(KEY, key);
1521INPUT_DEV_CAP_ATTR(REL, rel);
1522INPUT_DEV_CAP_ATTR(ABS, abs);
1523INPUT_DEV_CAP_ATTR(MSC, msc);
1524INPUT_DEV_CAP_ATTR(LED, led);
1525INPUT_DEV_CAP_ATTR(SND, snd);
1526INPUT_DEV_CAP_ATTR(FF, ff);
1527INPUT_DEV_CAP_ATTR(SW, sw);
1528
1529static struct attribute *input_dev_caps_attrs[] = {
1530	&dev_attr_ev.attr,
1531	&dev_attr_key.attr,
1532	&dev_attr_rel.attr,
1533	&dev_attr_abs.attr,
1534	&dev_attr_msc.attr,
1535	&dev_attr_led.attr,
1536	&dev_attr_snd.attr,
1537	&dev_attr_ff.attr,
1538	&dev_attr_sw.attr,
1539	NULL
1540};
1541
1542static const struct attribute_group input_dev_caps_attr_group = {
1543	.name	= "capabilities",
1544	.attrs	= input_dev_caps_attrs,
1545};
1546
1547static const struct attribute_group *input_dev_attr_groups[] = {
1548	&input_dev_attr_group,
1549	&input_dev_id_attr_group,
1550	&input_dev_caps_attr_group,
1551	&input_poller_attribute_group,
1552	NULL
1553};
1554
1555static void input_dev_release(struct device *device)
1556{
1557	struct input_dev *dev = to_input_dev(device);
1558
1559	input_ff_destroy(dev);
1560	input_mt_destroy_slots(dev);
1561	kfree(dev->poller);
1562	kfree(dev->absinfo);
1563	kfree(dev->vals);
1564	kfree(dev);
1565
1566	module_put(THIS_MODULE);
1567}
1568
1569/*
1570 * Input uevent interface - loading event handlers based on
1571 * device bitfields.
1572 */
1573static int input_add_uevent_bm_var(struct kobj_uevent_env *env,
1574				   const char *name, const unsigned long *bitmap, int max)
1575{
1576	int len;
1577
1578	if (add_uevent_var(env, "%s", name))
1579		return -ENOMEM;
1580
1581	len = input_print_bitmap(&env->buf[env->buflen - 1],
1582				 sizeof(env->buf) - env->buflen,
1583				 bitmap, max, false);
1584	if (len >= (sizeof(env->buf) - env->buflen))
1585		return -ENOMEM;
1586
1587	env->buflen += len;
1588	return 0;
1589}
1590
1591/*
1592 * This is a pretty gross hack. When building uevent data the driver core
1593 * may try adding more environment variables to kobj_uevent_env without
1594 * telling us, so we have no idea how much of the buffer we can use to
1595 * avoid overflows/-ENOMEM elsewhere. To work around this let's artificially
1596 * reduce amount of memory we will use for the modalias environment variable.
1597 *
1598 * The potential additions are:
1599 *
1600 * SEQNUM=18446744073709551615 - (%llu - 28 bytes)
1601 * HOME=/ (6 bytes)
1602 * PATH=/sbin:/bin:/usr/sbin:/usr/bin (34 bytes)
1603 *
1604 * 68 bytes total. Allow extra buffer - 96 bytes
1605 */
1606#define UEVENT_ENV_EXTRA_LEN	96
1607
1608static int input_add_uevent_modalias_var(struct kobj_uevent_env *env,
1609					 const struct input_dev *dev)
1610{
1611	int len;
1612
1613	if (add_uevent_var(env, "MODALIAS="))
1614		return -ENOMEM;
1615
1616	len = input_print_modalias(&env->buf[env->buflen - 1],
1617				   (int)sizeof(env->buf) - env->buflen -
1618					UEVENT_ENV_EXTRA_LEN,
1619				   dev);
1620	if (len >= ((int)sizeof(env->buf) - env->buflen -
1621					UEVENT_ENV_EXTRA_LEN))
1622		return -ENOMEM;
1623
1624	env->buflen += len;
1625	return 0;
1626}
1627
1628#define INPUT_ADD_HOTPLUG_VAR(fmt, val...)				\
1629	do {								\
1630		int err = add_uevent_var(env, fmt, val);		\
1631		if (err)						\
1632			return err;					\
1633	} while (0)
1634
1635#define INPUT_ADD_HOTPLUG_BM_VAR(name, bm, max)				\
1636	do {								\
1637		int err = input_add_uevent_bm_var(env, name, bm, max);	\
1638		if (err)						\
1639			return err;					\
1640	} while (0)
1641
1642#define INPUT_ADD_HOTPLUG_MODALIAS_VAR(dev)				\
1643	do {								\
1644		int err = input_add_uevent_modalias_var(env, dev);	\
1645		if (err)						\
1646			return err;					\
1647	} while (0)
1648
1649static int input_dev_uevent(const struct device *device, struct kobj_uevent_env *env)
1650{
1651	const struct input_dev *dev = to_input_dev(device);
1652
1653	INPUT_ADD_HOTPLUG_VAR("PRODUCT=%x/%x/%x/%x",
1654				dev->id.bustype, dev->id.vendor,
1655				dev->id.product, dev->id.version);
1656	if (dev->name)
1657		INPUT_ADD_HOTPLUG_VAR("NAME=\"%s\"", dev->name);
1658	if (dev->phys)
1659		INPUT_ADD_HOTPLUG_VAR("PHYS=\"%s\"", dev->phys);
1660	if (dev->uniq)
1661		INPUT_ADD_HOTPLUG_VAR("UNIQ=\"%s\"", dev->uniq);
1662
1663	INPUT_ADD_HOTPLUG_BM_VAR("PROP=", dev->propbit, INPUT_PROP_MAX);
1664
1665	INPUT_ADD_HOTPLUG_BM_VAR("EV=", dev->evbit, EV_MAX);
1666	if (test_bit(EV_KEY, dev->evbit))
1667		INPUT_ADD_HOTPLUG_BM_VAR("KEY=", dev->keybit, KEY_MAX);
1668	if (test_bit(EV_REL, dev->evbit))
1669		INPUT_ADD_HOTPLUG_BM_VAR("REL=", dev->relbit, REL_MAX);
1670	if (test_bit(EV_ABS, dev->evbit))
1671		INPUT_ADD_HOTPLUG_BM_VAR("ABS=", dev->absbit, ABS_MAX);
1672	if (test_bit(EV_MSC, dev->evbit))
1673		INPUT_ADD_HOTPLUG_BM_VAR("MSC=", dev->mscbit, MSC_MAX);
1674	if (test_bit(EV_LED, dev->evbit))
1675		INPUT_ADD_HOTPLUG_BM_VAR("LED=", dev->ledbit, LED_MAX);
1676	if (test_bit(EV_SND, dev->evbit))
1677		INPUT_ADD_HOTPLUG_BM_VAR("SND=", dev->sndbit, SND_MAX);
1678	if (test_bit(EV_FF, dev->evbit))
1679		INPUT_ADD_HOTPLUG_BM_VAR("FF=", dev->ffbit, FF_MAX);
1680	if (test_bit(EV_SW, dev->evbit))
1681		INPUT_ADD_HOTPLUG_BM_VAR("SW=", dev->swbit, SW_MAX);
1682
1683	INPUT_ADD_HOTPLUG_MODALIAS_VAR(dev);
1684
1685	return 0;
1686}
1687
1688#define INPUT_DO_TOGGLE(dev, type, bits, on)				\
1689	do {								\
1690		int i;							\
1691		bool active;						\
1692									\
1693		if (!test_bit(EV_##type, dev->evbit))			\
1694			break;						\
1695									\
1696		for_each_set_bit(i, dev->bits##bit, type##_CNT) {	\
1697			active = test_bit(i, dev->bits);		\
1698			if (!active && !on)				\
1699				continue;				\
1700									\
1701			dev->event(dev, EV_##type, i, on ? active : 0);	\
1702		}							\
1703	} while (0)
1704
1705static void input_dev_toggle(struct input_dev *dev, bool activate)
1706{
1707	if (!dev->event)
1708		return;
1709
1710	INPUT_DO_TOGGLE(dev, LED, led, activate);
1711	INPUT_DO_TOGGLE(dev, SND, snd, activate);
1712
1713	if (activate && test_bit(EV_REP, dev->evbit)) {
1714		dev->event(dev, EV_REP, REP_PERIOD, dev->rep[REP_PERIOD]);
1715		dev->event(dev, EV_REP, REP_DELAY, dev->rep[REP_DELAY]);
1716	}
1717}
1718
1719/**
1720 * input_reset_device() - reset/restore the state of input device
1721 * @dev: input device whose state needs to be reset
1722 *
1723 * This function tries to reset the state of an opened input device and
1724 * bring internal state and state if the hardware in sync with each other.
1725 * We mark all keys as released, restore LED state, repeat rate, etc.
1726 */
1727void input_reset_device(struct input_dev *dev)
1728{
1729	guard(mutex)(&dev->mutex);
1730	guard(spinlock_irqsave)(&dev->event_lock);
1731
1732	input_dev_toggle(dev, true);
1733	if (input_dev_release_keys(dev))
1734		input_handle_event(dev, EV_SYN, SYN_REPORT, 1);
1735}
1736EXPORT_SYMBOL(input_reset_device);
1737
1738static int input_inhibit_device(struct input_dev *dev)
1739{
1740	guard(mutex)(&dev->mutex);
1741
1742	if (dev->inhibited)
1743		return 0;
1744
1745	if (dev->users) {
1746		if (dev->close)
1747			dev->close(dev);
1748		if (dev->poller)
1749			input_dev_poller_stop(dev->poller);
1750	}
1751
1752	scoped_guard(spinlock_irq, &dev->event_lock) {
1753		input_mt_release_slots(dev);
1754		input_dev_release_keys(dev);
1755		input_handle_event(dev, EV_SYN, SYN_REPORT, 1);
1756		input_dev_toggle(dev, false);
1757	}
1758
1759	dev->inhibited = true;
1760
1761	return 0;
1762}
1763
1764static int input_uninhibit_device(struct input_dev *dev)
1765{
1766	int error;
1767
1768	guard(mutex)(&dev->mutex);
1769
1770	if (!dev->inhibited)
1771		return 0;
1772
1773	if (dev->users) {
1774		if (dev->open) {
1775			error = dev->open(dev);
1776			if (error)
1777				return error;
1778		}
1779		if (dev->poller)
1780			input_dev_poller_start(dev->poller);
1781	}
1782
1783	dev->inhibited = false;
1784
1785	scoped_guard(spinlock_irq, &dev->event_lock)
1786		input_dev_toggle(dev, true);
1787
1788	return 0;
1789}
1790
1791static int input_dev_suspend(struct device *dev)
1792{
1793	struct input_dev *input_dev = to_input_dev(dev);
1794
1795	guard(spinlock_irq)(&input_dev->event_lock);
1796
1797	/*
1798	 * Keys that are pressed now are unlikely to be
1799	 * still pressed when we resume.
1800	 */
1801	if (input_dev_release_keys(input_dev))
1802		input_handle_event(input_dev, EV_SYN, SYN_REPORT, 1);
1803
1804	/* Turn off LEDs and sounds, if any are active. */
1805	input_dev_toggle(input_dev, false);
1806
1807	return 0;
1808}
1809
1810static int input_dev_resume(struct device *dev)
1811{
1812	struct input_dev *input_dev = to_input_dev(dev);
1813
1814	guard(spinlock_irq)(&input_dev->event_lock);
1815
1816	/* Restore state of LEDs and sounds, if any were active. */
1817	input_dev_toggle(input_dev, true);
1818
1819	return 0;
1820}
1821
1822static int input_dev_freeze(struct device *dev)
1823{
1824	struct input_dev *input_dev = to_input_dev(dev);
1825
1826	guard(spinlock_irq)(&input_dev->event_lock);
1827
1828	/*
1829	 * Keys that are pressed now are unlikely to be
1830	 * still pressed when we resume.
1831	 */
1832	if (input_dev_release_keys(input_dev))
1833		input_handle_event(input_dev, EV_SYN, SYN_REPORT, 1);
1834
1835	return 0;
1836}
1837
1838static int input_dev_poweroff(struct device *dev)
1839{
1840	struct input_dev *input_dev = to_input_dev(dev);
1841
1842	guard(spinlock_irq)(&input_dev->event_lock);
1843
1844	/* Turn off LEDs and sounds, if any are active. */
1845	input_dev_toggle(input_dev, false);
1846
1847	return 0;
1848}
1849
1850static const struct dev_pm_ops input_dev_pm_ops = {
1851	.suspend	= input_dev_suspend,
1852	.resume		= input_dev_resume,
1853	.freeze		= input_dev_freeze,
1854	.poweroff	= input_dev_poweroff,
1855	.restore	= input_dev_resume,
1856};
1857
1858static const struct device_type input_dev_type = {
1859	.groups		= input_dev_attr_groups,
1860	.release	= input_dev_release,
1861	.uevent		= input_dev_uevent,
1862	.pm		= pm_sleep_ptr(&input_dev_pm_ops),
1863};
1864
1865static char *input_devnode(const struct device *dev, umode_t *mode)
1866{
1867	return kasprintf(GFP_KERNEL, "input/%s", dev_name(dev));
1868}
1869
1870const struct class input_class = {
1871	.name		= "input",
1872	.devnode	= input_devnode,
1873};
1874EXPORT_SYMBOL_GPL(input_class);
1875
1876/**
1877 * input_allocate_device - allocate memory for new input device
1878 *
1879 * Returns prepared struct input_dev or %NULL.
1880 *
1881 * NOTE: Use input_free_device() to free devices that have not been
1882 * registered; input_unregister_device() should be used for already
1883 * registered devices.
1884 */
1885struct input_dev *input_allocate_device(void)
1886{
1887	static atomic_t input_no = ATOMIC_INIT(-1);
1888	struct input_dev *dev;
1889
1890	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1891	if (!dev)
1892		return NULL;
1893
1894	/*
1895	 * Start with space for SYN_REPORT + 7 EV_KEY/EV_MSC events + 2 spare,
1896	 * see input_estimate_events_per_packet(). We will tune the number
1897	 * when we register the device.
1898	 */
1899	dev->max_vals = 10;
1900	dev->vals = kcalloc(dev->max_vals, sizeof(*dev->vals), GFP_KERNEL);
1901	if (!dev->vals) {
1902		kfree(dev);
1903		return NULL;
1904	}
1905
1906	mutex_init(&dev->mutex);
1907	spin_lock_init(&dev->event_lock);
1908	timer_setup(&dev->timer, NULL, 0);
1909	INIT_LIST_HEAD(&dev->h_list);
1910	INIT_LIST_HEAD(&dev->node);
1911
1912	dev->dev.type = &input_dev_type;
1913	dev->dev.class = &input_class;
1914	device_initialize(&dev->dev);
1915	/*
1916	 * From this point on we can no longer simply "kfree(dev)", we need
1917	 * to use input_free_device() so that device core properly frees its
1918	 * resources associated with the input device.
1919	 */
1920
1921	dev_set_name(&dev->dev, "input%lu",
1922		     (unsigned long)atomic_inc_return(&input_no));
1923
1924	__module_get(THIS_MODULE);
1925
1926	return dev;
1927}
1928EXPORT_SYMBOL(input_allocate_device);
1929
1930struct input_devres {
1931	struct input_dev *input;
1932};
1933
1934static int devm_input_device_match(struct device *dev, void *res, void *data)
1935{
1936	struct input_devres *devres = res;
1937
1938	return devres->input == data;
1939}
1940
1941static void devm_input_device_release(struct device *dev, void *res)
1942{
1943	struct input_devres *devres = res;
1944	struct input_dev *input = devres->input;
1945
1946	dev_dbg(dev, "%s: dropping reference to %s\n",
1947		__func__, dev_name(&input->dev));
1948	input_put_device(input);
1949}
1950
1951/**
1952 * devm_input_allocate_device - allocate managed input device
1953 * @dev: device owning the input device being created
1954 *
1955 * Returns prepared struct input_dev or %NULL.
1956 *
1957 * Managed input devices do not need to be explicitly unregistered or
1958 * freed as it will be done automatically when owner device unbinds from
1959 * its driver (or binding fails). Once managed input device is allocated,
1960 * it is ready to be set up and registered in the same fashion as regular
1961 * input device. There are no special devm_input_device_[un]register()
1962 * variants, regular ones work with both managed and unmanaged devices,
1963 * should you need them. In most cases however, managed input device need
1964 * not be explicitly unregistered or freed.
1965 *
1966 * NOTE: the owner device is set up as parent of input device and users
1967 * should not override it.
1968 */
1969struct input_dev *devm_input_allocate_device(struct device *dev)
1970{
1971	struct input_dev *input;
1972	struct input_devres *devres;
1973
1974	devres = devres_alloc(devm_input_device_release,
1975			      sizeof(*devres), GFP_KERNEL);
1976	if (!devres)
1977		return NULL;
1978
1979	input = input_allocate_device();
1980	if (!input) {
1981		devres_free(devres);
1982		return NULL;
1983	}
1984
1985	input->dev.parent = dev;
1986	input->devres_managed = true;
1987
1988	devres->input = input;
1989	devres_add(dev, devres);
1990
1991	return input;
1992}
1993EXPORT_SYMBOL(devm_input_allocate_device);
1994
1995/**
1996 * input_free_device - free memory occupied by input_dev structure
1997 * @dev: input device to free
1998 *
1999 * This function should only be used if input_register_device()
2000 * was not called yet or if it failed. Once device was registered
2001 * use input_unregister_device() and memory will be freed once last
2002 * reference to the device is dropped.
2003 *
2004 * Device should be allocated by input_allocate_device().
2005 *
2006 * NOTE: If there are references to the input device then memory
2007 * will not be freed until last reference is dropped.
2008 */
2009void input_free_device(struct input_dev *dev)
2010{
2011	if (dev) {
2012		if (dev->devres_managed)
2013			WARN_ON(devres_destroy(dev->dev.parent,
2014						devm_input_device_release,
2015						devm_input_device_match,
2016						dev));
2017		input_put_device(dev);
2018	}
2019}
2020EXPORT_SYMBOL(input_free_device);
2021
2022/**
2023 * input_set_timestamp - set timestamp for input events
2024 * @dev: input device to set timestamp for
2025 * @timestamp: the time at which the event has occurred
2026 *   in CLOCK_MONOTONIC
2027 *
2028 * This function is intended to provide to the input system a more
2029 * accurate time of when an event actually occurred. The driver should
2030 * call this function as soon as a timestamp is acquired ensuring
2031 * clock conversions in input_set_timestamp are done correctly.
2032 *
2033 * The system entering suspend state between timestamp acquisition and
2034 * calling input_set_timestamp can result in inaccurate conversions.
2035 */
2036void input_set_timestamp(struct input_dev *dev, ktime_t timestamp)
2037{
2038	dev->timestamp[INPUT_CLK_MONO] = timestamp;
2039	dev->timestamp[INPUT_CLK_REAL] = ktime_mono_to_real(timestamp);
2040	dev->timestamp[INPUT_CLK_BOOT] = ktime_mono_to_any(timestamp,
2041							   TK_OFFS_BOOT);
2042}
2043EXPORT_SYMBOL(input_set_timestamp);
2044
2045/**
2046 * input_get_timestamp - get timestamp for input events
2047 * @dev: input device to get timestamp from
2048 *
2049 * A valid timestamp is a timestamp of non-zero value.
2050 */
2051ktime_t *input_get_timestamp(struct input_dev *dev)
2052{
2053	const ktime_t invalid_timestamp = ktime_set(0, 0);
2054
2055	if (!ktime_compare(dev->timestamp[INPUT_CLK_MONO], invalid_timestamp))
2056		input_set_timestamp(dev, ktime_get());
2057
2058	return dev->timestamp;
2059}
2060EXPORT_SYMBOL(input_get_timestamp);
2061
2062/**
2063 * input_set_capability - mark device as capable of a certain event
2064 * @dev: device that is capable of emitting or accepting event
2065 * @type: type of the event (EV_KEY, EV_REL, etc...)
2066 * @code: event code
2067 *
2068 * In addition to setting up corresponding bit in appropriate capability
2069 * bitmap the function also adjusts dev->evbit.
2070 */
2071void input_set_capability(struct input_dev *dev, unsigned int type, unsigned int code)
2072{
2073	if (type < EV_CNT && input_max_code[type] &&
2074	    code > input_max_code[type]) {
2075		pr_err("%s: invalid code %u for type %u\n", __func__, code,
2076		       type);
2077		dump_stack();
2078		return;
2079	}
2080
2081	switch (type) {
2082	case EV_KEY:
2083		__set_bit(code, dev->keybit);
2084		break;
2085
2086	case EV_REL:
2087		__set_bit(code, dev->relbit);
2088		break;
2089
2090	case EV_ABS:
2091		input_alloc_absinfo(dev);
2092		__set_bit(code, dev->absbit);
2093		break;
2094
2095	case EV_MSC:
2096		__set_bit(code, dev->mscbit);
2097		break;
2098
2099	case EV_SW:
2100		__set_bit(code, dev->swbit);
2101		break;
2102
2103	case EV_LED:
2104		__set_bit(code, dev->ledbit);
2105		break;
2106
2107	case EV_SND:
2108		__set_bit(code, dev->sndbit);
2109		break;
2110
2111	case EV_FF:
2112		__set_bit(code, dev->ffbit);
2113		break;
2114
2115	case EV_PWR:
2116		/* do nothing */
2117		break;
2118
2119	default:
2120		pr_err("%s: unknown type %u (code %u)\n", __func__, type, code);
2121		dump_stack();
2122		return;
2123	}
2124
2125	__set_bit(type, dev->evbit);
2126}
2127EXPORT_SYMBOL(input_set_capability);
2128
2129static unsigned int input_estimate_events_per_packet(struct input_dev *dev)
2130{
2131	int mt_slots;
2132	int i;
2133	unsigned int events;
2134
2135	if (dev->mt) {
2136		mt_slots = dev->mt->num_slots;
2137	} else if (test_bit(ABS_MT_TRACKING_ID, dev->absbit)) {
2138		mt_slots = dev->absinfo[ABS_MT_TRACKING_ID].maximum -
2139			   dev->absinfo[ABS_MT_TRACKING_ID].minimum + 1;
2140		mt_slots = clamp(mt_slots, 2, 32);
2141	} else if (test_bit(ABS_MT_POSITION_X, dev->absbit)) {
2142		mt_slots = 2;
2143	} else {
2144		mt_slots = 0;
2145	}
2146
2147	events = mt_slots + 1; /* count SYN_MT_REPORT and SYN_REPORT */
2148
2149	if (test_bit(EV_ABS, dev->evbit))
2150		for_each_set_bit(i, dev->absbit, ABS_CNT)
2151			events += input_is_mt_axis(i) ? mt_slots : 1;
2152
2153	if (test_bit(EV_REL, dev->evbit))
2154		events += bitmap_weight(dev->relbit, REL_CNT);
2155
2156	/* Make room for KEY and MSC events */
2157	events += 7;
2158
2159	return events;
2160}
2161
2162#define INPUT_CLEANSE_BITMASK(dev, type, bits)				\
2163	do {								\
2164		if (!test_bit(EV_##type, dev->evbit))			\
2165			memset(dev->bits##bit, 0,			\
2166				sizeof(dev->bits##bit));		\
2167	} while (0)
2168
2169static void input_cleanse_bitmasks(struct input_dev *dev)
2170{
2171	INPUT_CLEANSE_BITMASK(dev, KEY, key);
2172	INPUT_CLEANSE_BITMASK(dev, REL, rel);
2173	INPUT_CLEANSE_BITMASK(dev, ABS, abs);
2174	INPUT_CLEANSE_BITMASK(dev, MSC, msc);
2175	INPUT_CLEANSE_BITMASK(dev, LED, led);
2176	INPUT_CLEANSE_BITMASK(dev, SND, snd);
2177	INPUT_CLEANSE_BITMASK(dev, FF, ff);
2178	INPUT_CLEANSE_BITMASK(dev, SW, sw);
2179}
2180
2181static void __input_unregister_device(struct input_dev *dev)
2182{
2183	struct input_handle *handle, *next;
2184
2185	input_disconnect_device(dev);
2186
2187	scoped_guard(mutex, &input_mutex) {
2188		list_for_each_entry_safe(handle, next, &dev->h_list, d_node)
2189			handle->handler->disconnect(handle);
2190		WARN_ON(!list_empty(&dev->h_list));
2191
2192		timer_delete_sync(&dev->timer);
2193		list_del_init(&dev->node);
2194
2195		input_wakeup_procfs_readers();
2196	}
2197
2198	device_del(&dev->dev);
2199}
2200
2201static void devm_input_device_unregister(struct device *dev, void *res)
2202{
2203	struct input_devres *devres = res;
2204	struct input_dev *input = devres->input;
2205
2206	dev_dbg(dev, "%s: unregistering device %s\n",
2207		__func__, dev_name(&input->dev));
2208	__input_unregister_device(input);
2209}
2210
2211/*
2212 * Generate software autorepeat event. Note that we take
2213 * dev->event_lock here to avoid racing with input_event
2214 * which may cause keys get "stuck".
2215 */
2216static void input_repeat_key(struct timer_list *t)
2217{
2218	struct input_dev *dev = timer_container_of(dev, t, timer);
2219
2220	guard(spinlock_irqsave)(&dev->event_lock);
2221
2222	if (!dev->inhibited &&
2223	    test_bit(dev->repeat_key, dev->key) &&
2224	    is_event_supported(dev->repeat_key, dev->keybit, KEY_MAX)) {
2225
2226		input_set_timestamp(dev, ktime_get());
2227		input_handle_event(dev, EV_KEY, dev->repeat_key, 2);
2228		input_handle_event(dev, EV_SYN, SYN_REPORT, 1);
2229
2230		if (dev->rep[REP_PERIOD])
2231			mod_timer(&dev->timer, jiffies +
2232					msecs_to_jiffies(dev->rep[REP_PERIOD]));
2233	}
2234}
2235
2236/**
2237 * input_enable_softrepeat - enable software autorepeat
2238 * @dev: input device
2239 * @delay: repeat delay
2240 * @period: repeat period
2241 *
2242 * Enable software autorepeat on the input device.
2243 */
2244void input_enable_softrepeat(struct input_dev *dev, int delay, int period)
2245{
2246	dev->timer.function = input_repeat_key;
2247	dev->rep[REP_DELAY] = delay;
2248	dev->rep[REP_PERIOD] = period;
2249}
2250EXPORT_SYMBOL(input_enable_softrepeat);
2251
2252bool input_device_enabled(struct input_dev *dev)
2253{
2254	lockdep_assert_held(&dev->mutex);
2255
2256	return !dev->inhibited && dev->users > 0;
2257}
2258EXPORT_SYMBOL_GPL(input_device_enabled);
2259
2260static int input_device_tune_vals(struct input_dev *dev)
2261{
2262	struct input_value *vals;
2263	unsigned int packet_size;
2264	unsigned int max_vals;
2265
2266	packet_size = input_estimate_events_per_packet(dev);
2267	if (dev->hint_events_per_packet < packet_size)
2268		dev->hint_events_per_packet = packet_size;
2269
2270	max_vals = dev->hint_events_per_packet + 2;
2271	if (dev->max_vals >= max_vals)
2272		return 0;
2273
2274	vals = kcalloc(max_vals, sizeof(*vals), GFP_KERNEL);
2275	if (!vals)
2276		return -ENOMEM;
2277
2278	scoped_guard(spinlock_irq, &dev->event_lock) {
2279		dev->max_vals = max_vals;
2280		swap(dev->vals, vals);
2281	}
2282
2283	/* Because of swap() above, this frees the old vals memory */
2284	kfree(vals);
2285
2286	return 0;
2287}
2288
2289/**
2290 * input_register_device - register device with input core
2291 * @dev: device to be registered
2292 *
2293 * This function registers device with input core. The device must be
2294 * allocated with input_allocate_device() and all it's capabilities
2295 * set up before registering.
2296 * If function fails the device must be freed with input_free_device().
2297 * Once device has been successfully registered it can be unregistered
2298 * with input_unregister_device(); input_free_device() should not be
2299 * called in this case.
2300 *
2301 * Note that this function is also used to register managed input devices
2302 * (ones allocated with devm_input_allocate_device()). Such managed input
2303 * devices need not be explicitly unregistered or freed, their tear down
2304 * is controlled by the devres infrastructure. It is also worth noting
2305 * that tear down of managed input devices is internally a 2-step process:
2306 * registered managed input device is first unregistered, but stays in
2307 * memory and can still handle input_event() calls (although events will
2308 * not be delivered anywhere). The freeing of managed input device will
2309 * happen later, when devres stack is unwound to the point where device
2310 * allocation was made.
2311 */
2312int input_register_device(struct input_dev *dev)
2313{
2314	struct input_devres *devres = NULL;
2315	struct input_handler *handler;
2316	const char *path;
2317	int error;
2318
2319	if (test_bit(EV_ABS, dev->evbit) && !dev->absinfo) {
2320		dev_err(&dev->dev,
2321			"Absolute device without dev->absinfo, refusing to register\n");
2322		return -EINVAL;
2323	}
2324
2325	if (dev->devres_managed) {
2326		devres = devres_alloc(devm_input_device_unregister,
2327				      sizeof(*devres), GFP_KERNEL);
2328		if (!devres)
2329			return -ENOMEM;
2330
2331		devres->input = dev;
2332	}
2333
2334	/* Every input device generates EV_SYN/SYN_REPORT events. */
2335	__set_bit(EV_SYN, dev->evbit);
2336
2337	/* KEY_RESERVED is not supposed to be transmitted to userspace. */
2338	__clear_bit(KEY_RESERVED, dev->keybit);
2339
2340	/* Make sure that bitmasks not mentioned in dev->evbit are clean. */
2341	input_cleanse_bitmasks(dev);
2342
2343	error = input_device_tune_vals(dev);
2344	if (error)
2345		goto err_devres_free;
2346
2347	/*
2348	 * If delay and period are pre-set by the driver, then autorepeating
2349	 * is handled by the driver itself and we don't do it in input.c.
2350	 */
2351	if (!dev->rep[REP_DELAY] && !dev->rep[REP_PERIOD])
2352		input_enable_softrepeat(dev, 250, 33);
2353
2354	if (!dev->getkeycode)
2355		dev->getkeycode = input_default_getkeycode;
2356
2357	if (!dev->setkeycode)
2358		dev->setkeycode = input_default_setkeycode;
2359
2360	if (dev->poller)
2361		input_dev_poller_finalize(dev->poller);
2362
2363	error = device_add(&dev->dev);
2364	if (error)
2365		goto err_devres_free;
2366
2367	path = kobject_get_path(&dev->dev.kobj, GFP_KERNEL);
2368	pr_info("%s as %s\n",
2369		dev->name ? dev->name : "Unspecified device",
2370		path ? path : "N/A");
2371	kfree(path);
2372
2373	error = -EINTR;
2374	scoped_cond_guard(mutex_intr, goto err_device_del, &input_mutex) {
2375		list_add_tail(&dev->node, &input_dev_list);
2376
2377		list_for_each_entry(handler, &input_handler_list, node)
2378			input_attach_handler(dev, handler);
2379
2380		input_wakeup_procfs_readers();
2381	}
2382
2383	if (dev->devres_managed) {
2384		dev_dbg(dev->dev.parent, "%s: registering %s with devres.\n",
2385			__func__, dev_name(&dev->dev));
2386		devres_add(dev->dev.parent, devres);
2387	}
2388	return 0;
2389
2390err_device_del:
2391	device_del(&dev->dev);
2392err_devres_free:
2393	devres_free(devres);
2394	return error;
2395}
2396EXPORT_SYMBOL(input_register_device);
2397
2398/**
2399 * input_unregister_device - unregister previously registered device
2400 * @dev: device to be unregistered
2401 *
2402 * This function unregisters an input device. Once device is unregistered
2403 * the caller should not try to access it as it may get freed at any moment.
2404 */
2405void input_unregister_device(struct input_dev *dev)
2406{
2407	if (dev->devres_managed) {
2408		WARN_ON(devres_destroy(dev->dev.parent,
2409					devm_input_device_unregister,
2410					devm_input_device_match,
2411					dev));
2412		__input_unregister_device(dev);
2413		/*
2414		 * We do not do input_put_device() here because it will be done
2415		 * when 2nd devres fires up.
2416		 */
2417	} else {
2418		__input_unregister_device(dev);
2419		input_put_device(dev);
2420	}
2421}
2422EXPORT_SYMBOL(input_unregister_device);
2423
2424static int input_handler_check_methods(const struct input_handler *handler)
2425{
2426	int count = 0;
2427
2428	if (handler->filter)
2429		count++;
2430	if (handler->events)
2431		count++;
2432	if (handler->event)
2433		count++;
2434
2435	if (count > 1) {
2436		pr_err("%s: only one event processing method can be defined (%s)\n",
2437		       __func__, handler->name);
2438		return -EINVAL;
2439	}
2440
2441	return 0;
2442}
2443
2444/**
2445 * input_register_handler - register a new input handler
2446 * @handler: handler to be registered
2447 *
2448 * This function registers a new input handler (interface) for input
2449 * devices in the system and attaches it to all input devices that
2450 * are compatible with the handler.
2451 */
2452int input_register_handler(struct input_handler *handler)
2453{
2454	struct input_dev *dev;
2455	int error;
2456
2457	error = input_handler_check_methods(handler);
2458	if (error)
2459		return error;
2460
2461	scoped_cond_guard(mutex_intr, return -EINTR, &input_mutex) {
2462		INIT_LIST_HEAD(&handler->h_list);
2463
2464		list_add_tail(&handler->node, &input_handler_list);
2465
2466		list_for_each_entry(dev, &input_dev_list, node)
2467			input_attach_handler(dev, handler);
2468
2469		input_wakeup_procfs_readers();
2470	}
2471
2472	return 0;
2473}
2474EXPORT_SYMBOL(input_register_handler);
2475
2476/**
2477 * input_unregister_handler - unregisters an input handler
2478 * @handler: handler to be unregistered
2479 *
2480 * This function disconnects a handler from its input devices and
2481 * removes it from lists of known handlers.
2482 */
2483void input_unregister_handler(struct input_handler *handler)
2484{
2485	struct input_handle *handle, *next;
2486
2487	guard(mutex)(&input_mutex);
2488
2489	list_for_each_entry_safe(handle, next, &handler->h_list, h_node)
2490		handler->disconnect(handle);
2491	WARN_ON(!list_empty(&handler->h_list));
2492
2493	list_del_init(&handler->node);
2494
2495	input_wakeup_procfs_readers();
2496}
2497EXPORT_SYMBOL(input_unregister_handler);
2498
2499/**
2500 * input_handler_for_each_handle - handle iterator
2501 * @handler: input handler to iterate
2502 * @data: data for the callback
2503 * @fn: function to be called for each handle
2504 *
2505 * Iterate over @bus's list of devices, and call @fn for each, passing
2506 * it @data and stop when @fn returns a non-zero value. The function is
2507 * using RCU to traverse the list and therefore may be using in atomic
2508 * contexts. The @fn callback is invoked from RCU critical section and
2509 * thus must not sleep.
2510 */
2511int input_handler_for_each_handle(struct input_handler *handler, void *data,
2512				  int (*fn)(struct input_handle *, void *))
2513{
2514	struct input_handle *handle;
2515	int retval;
2516
2517	guard(rcu)();
2518
2519	list_for_each_entry_rcu(handle, &handler->h_list, h_node) {
2520		retval = fn(handle, data);
2521		if (retval)
2522			return retval;
2523	}
2524
2525	return 0;
2526}
2527EXPORT_SYMBOL(input_handler_for_each_handle);
2528
2529/*
2530 * An implementation of input_handle's handle_events() method that simply
2531 * invokes handler->event() method for each event one by one.
2532 */
2533static unsigned int input_handle_events_default(struct input_handle *handle,
2534						struct input_value *vals,
2535						unsigned int count)
2536{
2537	struct input_handler *handler = handle->handler;
2538	struct input_value *v;
2539
2540	for (v = vals; v != vals + count; v++)
2541		handler->event(handle, v->type, v->code, v->value);
2542
2543	return count;
2544}
2545
2546/*
2547 * An implementation of input_handle's handle_events() method that invokes
2548 * handler->filter() method for each event one by one and removes events
2549 * that were filtered out from the "vals" array.
2550 */
2551static unsigned int input_handle_events_filter(struct input_handle *handle,
2552					       struct input_value *vals,
2553					       unsigned int count)
2554{
2555	struct input_handler *handler = handle->handler;
2556	struct input_value *end = vals;
2557	struct input_value *v;
2558
2559	for (v = vals; v != vals + count; v++) {
2560		if (handler->filter(handle, v->type, v->code, v->value))
2561			continue;
2562		if (end != v)
2563			*end = *v;
2564		end++;
2565	}
2566
2567	return end - vals;
2568}
2569
2570/*
2571 * An implementation of input_handle's handle_events() method that does nothing.
2572 */
2573static unsigned int input_handle_events_null(struct input_handle *handle,
2574					     struct input_value *vals,
2575					     unsigned int count)
2576{
2577	return count;
2578}
2579
2580/*
2581 * Sets up appropriate handle->event_handler based on the input_handler
2582 * associated with the handle.
2583 */
2584static void input_handle_setup_event_handler(struct input_handle *handle)
2585{
2586	struct input_handler *handler = handle->handler;
2587
2588	if (handler->filter)
2589		handle->handle_events = input_handle_events_filter;
2590	else if (handler->event)
2591		handle->handle_events = input_handle_events_default;
2592	else if (handler->events)
2593		handle->handle_events = handler->events;
2594	else
2595		handle->handle_events = input_handle_events_null;
2596}
2597
2598/**
2599 * input_register_handle - register a new input handle
2600 * @handle: handle to register
2601 *
2602 * This function puts a new input handle onto device's
2603 * and handler's lists so that events can flow through
2604 * it once it is opened using input_open_device().
2605 *
2606 * This function is supposed to be called from handler's
2607 * connect() method.
2608 */
2609int input_register_handle(struct input_handle *handle)
2610{
2611	struct input_handler *handler = handle->handler;
2612	struct input_dev *dev = handle->dev;
2613
2614	input_handle_setup_event_handler(handle);
2615	/*
2616	 * We take dev->mutex here to prevent race with
2617	 * input_release_device().
2618	 */
2619	scoped_cond_guard(mutex_intr, return -EINTR, &dev->mutex) {
2620		/*
2621		 * Filters go to the head of the list, normal handlers
2622		 * to the tail.
2623		 */
2624		if (handler->filter)
2625			list_add_rcu(&handle->d_node, &dev->h_list);
2626		else
2627			list_add_tail_rcu(&handle->d_node, &dev->h_list);
2628	}
2629
2630	/*
2631	 * Since we are supposed to be called from ->connect()
2632	 * which is mutually exclusive with ->disconnect()
2633	 * we can't be racing with input_unregister_handle()
2634	 * and so separate lock is not needed here.
2635	 */
2636	list_add_tail_rcu(&handle->h_node, &handler->h_list);
2637
2638	if (handler->start)
2639		handler->start(handle);
2640
2641	return 0;
2642}
2643EXPORT_SYMBOL(input_register_handle);
2644
2645/**
2646 * input_unregister_handle - unregister an input handle
2647 * @handle: handle to unregister
2648 *
2649 * This function removes input handle from device's
2650 * and handler's lists.
2651 *
2652 * This function is supposed to be called from handler's
2653 * disconnect() method.
2654 */
2655void input_unregister_handle(struct input_handle *handle)
2656{
2657	struct input_dev *dev = handle->dev;
2658
2659	list_del_rcu(&handle->h_node);
2660
2661	/*
2662	 * Take dev->mutex to prevent race with input_release_device().
2663	 */
2664	scoped_guard(mutex, &dev->mutex)
2665		list_del_rcu(&handle->d_node);
2666
2667	synchronize_rcu();
2668}
2669EXPORT_SYMBOL(input_unregister_handle);
2670
2671/**
2672 * input_get_new_minor - allocates a new input minor number
2673 * @legacy_base: beginning or the legacy range to be searched
2674 * @legacy_num: size of legacy range
2675 * @allow_dynamic: whether we can also take ID from the dynamic range
2676 *
2677 * This function allocates a new device minor for from input major namespace.
2678 * Caller can request legacy minor by specifying @legacy_base and @legacy_num
2679 * parameters and whether ID can be allocated from dynamic range if there are
2680 * no free IDs in legacy range.
2681 */
2682int input_get_new_minor(int legacy_base, unsigned int legacy_num,
2683			bool allow_dynamic)
2684{
2685	/*
2686	 * This function should be called from input handler's ->connect()
2687	 * methods, which are serialized with input_mutex, so no additional
2688	 * locking is needed here.
2689	 */
2690	if (legacy_base >= 0) {
2691		int minor = ida_alloc_range(&input_ida, legacy_base,
2692					    legacy_base + legacy_num - 1,
2693					    GFP_KERNEL);
2694		if (minor >= 0 || !allow_dynamic)
2695			return minor;
2696	}
2697
2698	return ida_alloc_range(&input_ida, INPUT_FIRST_DYNAMIC_DEV,
2699			       INPUT_MAX_CHAR_DEVICES - 1, GFP_KERNEL);
2700}
2701EXPORT_SYMBOL(input_get_new_minor);
2702
2703/**
2704 * input_free_minor - release previously allocated minor
2705 * @minor: minor to be released
2706 *
2707 * This function releases previously allocated input minor so that it can be
2708 * reused later.
2709 */
2710void input_free_minor(unsigned int minor)
2711{
2712	ida_free(&input_ida, minor);
2713}
2714EXPORT_SYMBOL(input_free_minor);
2715
2716static int __init input_init(void)
2717{
2718	int err;
2719
2720	err = class_register(&input_class);
2721	if (err) {
2722		pr_err("unable to register input_dev class\n");
2723		return err;
2724	}
2725
2726	err = input_proc_init();
2727	if (err)
2728		goto fail1;
2729
2730	err = register_chrdev_region(MKDEV(INPUT_MAJOR, 0),
2731				     INPUT_MAX_CHAR_DEVICES, "input");
2732	if (err) {
2733		pr_err("unable to register char major %d", INPUT_MAJOR);
2734		goto fail2;
2735	}
2736
2737	return 0;
2738
2739 fail2:	input_proc_exit();
2740 fail1:	class_unregister(&input_class);
2741	return err;
2742}
2743
2744static void __exit input_exit(void)
2745{
2746	input_proc_exit();
2747	unregister_chrdev_region(MKDEV(INPUT_MAJOR, 0),
2748				 INPUT_MAX_CHAR_DEVICES);
2749	class_unregister(&input_class);
2750}
2751
2752subsys_initcall(input_init);
2753module_exit(input_exit);