Version:  2.0.40 2.2.26 2.4.37 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4

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

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