Root/drivers/input/input.c

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

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