Version:  2.0.40 2.2.26 2.4.37 3.4 3.5 3.6 3.7 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

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         int code;
678 
679         if (is_event_supported(EV_KEY, dev->evbit, EV_MAX)) {
680                 for (code = 0; code <= KEY_MAX; code++) {
681                         if (is_event_supported(code, dev->keybit, KEY_MAX) &&
682                             __test_and_clear_bit(code, dev->key)) {
683                                 input_pass_event(dev, EV_KEY, code, 0);
684                         }
685                 }
686                 input_pass_event(dev, EV_SYN, SYN_REPORT, 1);
687         }
688 }
689 
690 /*
691  * Prepare device for unregistering
692  */
693 static void input_disconnect_device(struct input_dev *dev)
694 {
695         struct input_handle *handle;
696 
697         /*
698          * Mark device as going away. Note that we take dev->mutex here
699          * not to protect access to dev->going_away but rather to ensure
700          * that there are no threads in the middle of input_open_device()
701          */
702         mutex_lock(&dev->mutex);
703         dev->going_away = true;
704         mutex_unlock(&dev->mutex);
705 
706         spin_lock_irq(&dev->event_lock);
707 
708         /*
709          * Simulate keyup events for all pressed keys so that handlers
710          * are not left with "stuck" keys. The driver may continue
711          * generate events even after we done here but they will not
712          * reach any handlers.
713          */
714         input_dev_release_keys(dev);
715 
716         list_for_each_entry(handle, &dev->h_list, d_node)
717                 handle->open = 0;
718 
719         spin_unlock_irq(&dev->event_lock);
720 }
721 
722 /**
723  * input_scancode_to_scalar() - converts scancode in &struct input_keymap_entry
724  * @ke: keymap entry containing scancode to be converted.
725  * @scancode: pointer to the location where converted scancode should
726  *      be stored.
727  *
728  * This function is used to convert scancode stored in &struct keymap_entry
729  * into scalar form understood by legacy keymap handling methods. These
730  * methods expect scancodes to be represented as 'unsigned int'.
731  */
732 int input_scancode_to_scalar(const struct input_keymap_entry *ke,
733                              unsigned int *scancode)
734 {
735         switch (ke->len) {
736         case 1:
737                 *scancode = *((u8 *)ke->scancode);
738                 break;
739 
740         case 2:
741                 *scancode = *((u16 *)ke->scancode);
742                 break;
743 
744         case 4:
745                 *scancode = *((u32 *)ke->scancode);
746                 break;
747 
748         default:
749                 return -EINVAL;
750         }
751 
752         return 0;
753 }
754 EXPORT_SYMBOL(input_scancode_to_scalar);
755 
756 /*
757  * Those routines handle the default case where no [gs]etkeycode() is
758  * defined. In this case, an array indexed by the scancode is used.
759  */
760 
761 static unsigned int input_fetch_keycode(struct input_dev *dev,
762                                         unsigned int index)
763 {
764         switch (dev->keycodesize) {
765         case 1:
766                 return ((u8 *)dev->keycode)[index];
767 
768         case 2:
769                 return ((u16 *)dev->keycode)[index];
770 
771         default:
772                 return ((u32 *)dev->keycode)[index];
773         }
774 }
775 
776 static int input_default_getkeycode(struct input_dev *dev,
777                                     struct input_keymap_entry *ke)
778 {
779         unsigned int index;
780         int error;
781 
782         if (!dev->keycodesize)
783                 return -EINVAL;
784 
785         if (ke->flags & INPUT_KEYMAP_BY_INDEX)
786                 index = ke->index;
787         else {
788                 error = input_scancode_to_scalar(ke, &index);
789                 if (error)
790                         return error;
791         }
792 
793         if (index >= dev->keycodemax)
794                 return -EINVAL;
795 
796         ke->keycode = input_fetch_keycode(dev, index);
797         ke->index = index;
798         ke->len = sizeof(index);
799         memcpy(ke->scancode, &index, sizeof(index));
800 
801         return 0;
802 }
803 
804 static int input_default_setkeycode(struct input_dev *dev,
805                                     const struct input_keymap_entry *ke,
806                                     unsigned int *old_keycode)
807 {
808         unsigned int index;
809         int error;
810         int i;
811 
812         if (!dev->keycodesize)
813                 return -EINVAL;
814 
815         if (ke->flags & INPUT_KEYMAP_BY_INDEX) {
816                 index = ke->index;
817         } else {
818                 error = input_scancode_to_scalar(ke, &index);
819                 if (error)
820                         return error;
821         }
822 
823         if (index >= dev->keycodemax)
824                 return -EINVAL;
825 
826         if (dev->keycodesize < sizeof(ke->keycode) &&
827                         (ke->keycode >> (dev->keycodesize * 8)))
828                 return -EINVAL;
829 
830         switch (dev->keycodesize) {
831                 case 1: {
832                         u8 *k = (u8 *)dev->keycode;
833                         *old_keycode = k[index];
834                         k[index] = ke->keycode;
835                         break;
836                 }
837                 case 2: {
838                         u16 *k = (u16 *)dev->keycode;
839                         *old_keycode = k[index];
840                         k[index] = ke->keycode;
841                         break;
842                 }
843                 default: {
844                         u32 *k = (u32 *)dev->keycode;
845                         *old_keycode = k[index];
846                         k[index] = ke->keycode;
847                         break;
848                 }
849         }
850 
851         __clear_bit(*old_keycode, dev->keybit);
852         __set_bit(ke->keycode, dev->keybit);
853 
854         for (i = 0; i < dev->keycodemax; i++) {
855                 if (input_fetch_keycode(dev, i) == *old_keycode) {
856                         __set_bit(*old_keycode, dev->keybit);
857                         break; /* Setting the bit twice is useless, so break */
858                 }
859         }
860 
861         return 0;
862 }
863 
864 /**
865  * input_get_keycode - retrieve keycode currently mapped to a given scancode
866  * @dev: input device which keymap is being queried
867  * @ke: keymap entry
868  *
869  * This function should be called by anyone interested in retrieving current
870  * keymap. Presently evdev handlers use it.
871  */
872 int input_get_keycode(struct input_dev *dev, struct input_keymap_entry *ke)
873 {
874         unsigned long flags;
875         int retval;
876 
877         spin_lock_irqsave(&dev->event_lock, flags);
878         retval = dev->getkeycode(dev, ke);
879         spin_unlock_irqrestore(&dev->event_lock, flags);
880 
881         return retval;
882 }
883 EXPORT_SYMBOL(input_get_keycode);
884 
885 /**
886  * input_set_keycode - attribute a keycode to a given scancode
887  * @dev: input device which keymap is being updated
888  * @ke: new keymap entry
889  *
890  * This function should be called by anyone needing to update current
891  * keymap. Presently keyboard and evdev handlers use it.
892  */
893 int input_set_keycode(struct input_dev *dev,
894                       const struct input_keymap_entry *ke)
895 {
896         unsigned long flags;
897         unsigned int old_keycode;
898         int retval;
899 
900         if (ke->keycode > KEY_MAX)
901                 return -EINVAL;
902 
903         spin_lock_irqsave(&dev->event_lock, flags);
904 
905         retval = dev->setkeycode(dev, ke, &old_keycode);
906         if (retval)
907                 goto out;
908 
909         /* Make sure KEY_RESERVED did not get enabled. */
910         __clear_bit(KEY_RESERVED, dev->keybit);
911 
912         /*
913          * Simulate keyup event if keycode is not present
914          * in the keymap anymore
915          */
916         if (test_bit(EV_KEY, dev->evbit) &&
917             !is_event_supported(old_keycode, dev->keybit, KEY_MAX) &&
918             __test_and_clear_bit(old_keycode, dev->key)) {
919                 struct input_value vals[] =  {
920                         { EV_KEY, old_keycode, 0 },
921                         input_value_sync
922                 };
923 
924                 input_pass_values(dev, vals, ARRAY_SIZE(vals));
925         }
926 
927  out:
928         spin_unlock_irqrestore(&dev->event_lock, flags);
929 
930         return retval;
931 }
932 EXPORT_SYMBOL(input_set_keycode);
933 
934 static const struct input_device_id *input_match_device(struct input_handler *handler,
935                                                         struct input_dev *dev)
936 {
937         const struct input_device_id *id;
938 
939         for (id = handler->id_table; id->flags || id->driver_info; id++) {
940 
941                 if (id->flags & INPUT_DEVICE_ID_MATCH_BUS)
942                         if (id->bustype != dev->id.bustype)
943                                 continue;
944 
945                 if (id->flags & INPUT_DEVICE_ID_MATCH_VENDOR)
946                         if (id->vendor != dev->id.vendor)
947                                 continue;
948 
949                 if (id->flags & INPUT_DEVICE_ID_MATCH_PRODUCT)
950                         if (id->product != dev->id.product)
951                                 continue;
952 
953                 if (id->flags & INPUT_DEVICE_ID_MATCH_VERSION)
954                         if (id->version != dev->id.version)
955                                 continue;
956 
957                 if (!bitmap_subset(id->evbit, dev->evbit, EV_MAX))
958                         continue;
959 
960                 if (!bitmap_subset(id->keybit, dev->keybit, KEY_MAX))
961                         continue;
962 
963                 if (!bitmap_subset(id->relbit, dev->relbit, REL_MAX))
964                         continue;
965 
966                 if (!bitmap_subset(id->absbit, dev->absbit, ABS_MAX))
967                         continue;
968 
969                 if (!bitmap_subset(id->mscbit, dev->mscbit, MSC_MAX))
970                         continue;
971 
972                 if (!bitmap_subset(id->ledbit, dev->ledbit, LED_MAX))
973                         continue;
974 
975                 if (!bitmap_subset(id->sndbit, dev->sndbit, SND_MAX))
976                         continue;
977 
978                 if (!bitmap_subset(id->ffbit, dev->ffbit, FF_MAX))
979                         continue;
980 
981                 if (!bitmap_subset(id->swbit, dev->swbit, SW_MAX))
982                         continue;
983 
984                 if (!handler->match || handler->match(handler, dev))
985                         return id;
986         }
987 
988         return NULL;
989 }
990 
991 static int input_attach_handler(struct input_dev *dev, struct input_handler *handler)
992 {
993         const struct input_device_id *id;
994         int error;
995 
996         id = input_match_device(handler, dev);
997         if (!id)
998                 return -ENODEV;
999 
1000         error = handler->connect(handler, dev, id);
1001         if (error && error != -ENODEV)
1002                 pr_err("failed to attach handler %s to device %s, error: %d\n",
1003                        handler->name, kobject_name(&dev->dev.kobj), error);
1004 
1005         return error;
1006 }
1007 
1008 #ifdef CONFIG_COMPAT
1009 
1010 static int input_bits_to_string(char *buf, int buf_size,
1011                                 unsigned long bits, bool skip_empty)
1012 {
1013         int len = 0;
1014 
1015         if (INPUT_COMPAT_TEST) {
1016                 u32 dword = bits >> 32;
1017                 if (dword || !skip_empty)
1018                         len += snprintf(buf, buf_size, "%x ", dword);
1019 
1020                 dword = bits & 0xffffffffUL;
1021                 if (dword || !skip_empty || len)
1022                         len += snprintf(buf + len, max(buf_size - len, 0),
1023                                         "%x", dword);
1024         } else {
1025                 if (bits || !skip_empty)
1026                         len += snprintf(buf, buf_size, "%lx", bits);
1027         }
1028 
1029         return len;
1030 }
1031 
1032 #else /* !CONFIG_COMPAT */
1033 
1034 static int input_bits_to_string(char *buf, int buf_size,
1035                                 unsigned long bits, bool skip_empty)
1036 {
1037         return bits || !skip_empty ?
1038                 snprintf(buf, buf_size, "%lx", bits) : 0;
1039 }
1040 
1041 #endif
1042 
1043 #ifdef CONFIG_PROC_FS
1044 
1045 static struct proc_dir_entry *proc_bus_input_dir;
1046 static DECLARE_WAIT_QUEUE_HEAD(input_devices_poll_wait);
1047 static int input_devices_state;
1048 
1049 static inline void input_wakeup_procfs_readers(void)
1050 {
1051         input_devices_state++;
1052         wake_up(&input_devices_poll_wait);
1053 }
1054 
1055 static unsigned int input_proc_devices_poll(struct file *file, poll_table *wait)
1056 {
1057         poll_wait(file, &input_devices_poll_wait, wait);
1058         if (file->f_version != input_devices_state) {
1059                 file->f_version = input_devices_state;
1060                 return POLLIN | POLLRDNORM;
1061         }
1062 
1063         return 0;
1064 }
1065 
1066 union input_seq_state {
1067         struct {
1068                 unsigned short pos;
1069                 bool mutex_acquired;
1070         };
1071         void *p;
1072 };
1073 
1074 static void *input_devices_seq_start(struct seq_file *seq, loff_t *pos)
1075 {
1076         union input_seq_state *state = (union input_seq_state *)&seq->private;
1077         int error;
1078 
1079         /* We need to fit into seq->private pointer */
1080         BUILD_BUG_ON(sizeof(union input_seq_state) != sizeof(seq->private));
1081 
1082         error = mutex_lock_interruptible(&input_mutex);
1083         if (error) {
1084                 state->mutex_acquired = false;
1085                 return ERR_PTR(error);
1086         }
1087 
1088         state->mutex_acquired = true;
1089 
1090         return seq_list_start(&input_dev_list, *pos);
1091 }
1092 
1093 static void *input_devices_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1094 {
1095         return seq_list_next(v, &input_dev_list, pos);
1096 }
1097 
1098 static void input_seq_stop(struct seq_file *seq, void *v)
1099 {
1100         union input_seq_state *state = (union input_seq_state *)&seq->private;
1101 
1102         if (state->mutex_acquired)
1103                 mutex_unlock(&input_mutex);
1104 }
1105 
1106 static void input_seq_print_bitmap(struct seq_file *seq, const char *name,
1107                                    unsigned long *bitmap, int max)
1108 {
1109         int i;
1110         bool skip_empty = true;
1111         char buf[18];
1112 
1113         seq_printf(seq, "B: %s=", name);
1114 
1115         for (i = BITS_TO_LONGS(max) - 1; i >= 0; i--) {
1116                 if (input_bits_to_string(buf, sizeof(buf),
1117                                          bitmap[i], skip_empty)) {
1118                         skip_empty = false;
1119                         seq_printf(seq, "%s%s", buf, i > 0 ? " " : "");
1120                 }
1121         }
1122 
1123         /*
1124          * If no output was produced print a single 0.
1125          */
1126         if (skip_empty)
1127                 seq_puts(seq, "");
1128 
1129         seq_putc(seq, '\n');
1130 }
1131 
1132 static int input_devices_seq_show(struct seq_file *seq, void *v)
1133 {
1134         struct input_dev *dev = container_of(v, struct input_dev, node);
1135         const char *path = kobject_get_path(&dev->dev.kobj, GFP_KERNEL);
1136         struct input_handle *handle;
1137 
1138         seq_printf(seq, "I: Bus=%04x Vendor=%04x Product=%04x Version=%04x\n",
1139                    dev->id.bustype, dev->id.vendor, dev->id.product, dev->id.version);
1140 
1141         seq_printf(seq, "N: Name=\"%s\"\n", dev->name ? dev->name : "");
1142         seq_printf(seq, "P: Phys=%s\n", dev->phys ? dev->phys : "");
1143         seq_printf(seq, "S: Sysfs=%s\n", path ? path : "");
1144         seq_printf(seq, "U: Uniq=%s\n", dev->uniq ? dev->uniq : "");
1145         seq_printf(seq, "H: Handlers=");
1146 
1147         list_for_each_entry(handle, &dev->h_list, d_node)
1148                 seq_printf(seq, "%s ", handle->name);
1149         seq_putc(seq, '\n');
1150 
1151         input_seq_print_bitmap(seq, "PROP", dev->propbit, INPUT_PROP_MAX);
1152 
1153         input_seq_print_bitmap(seq, "EV", dev->evbit, EV_MAX);
1154         if (test_bit(EV_KEY, dev->evbit))
1155                 input_seq_print_bitmap(seq, "KEY", dev->keybit, KEY_MAX);
1156         if (test_bit(EV_REL, dev->evbit))
1157                 input_seq_print_bitmap(seq, "REL", dev->relbit, REL_MAX);
1158         if (test_bit(EV_ABS, dev->evbit))
1159                 input_seq_print_bitmap(seq, "ABS", dev->absbit, ABS_MAX);
1160         if (test_bit(EV_MSC, dev->evbit))
1161                 input_seq_print_bitmap(seq, "MSC", dev->mscbit, MSC_MAX);
1162         if (test_bit(EV_LED, dev->evbit))
1163                 input_seq_print_bitmap(seq, "LED", dev->ledbit, LED_MAX);
1164         if (test_bit(EV_SND, dev->evbit))
1165                 input_seq_print_bitmap(seq, "SND", dev->sndbit, SND_MAX);
1166         if (test_bit(EV_FF, dev->evbit))
1167                 input_seq_print_bitmap(seq, "FF", dev->ffbit, FF_MAX);
1168         if (test_bit(EV_SW, dev->evbit))
1169                 input_seq_print_bitmap(seq, "SW", dev->swbit, SW_MAX);
1170 
1171         seq_putc(seq, '\n');
1172 
1173         kfree(path);
1174         return 0;
1175 }
1176 
1177 static const struct seq_operations input_devices_seq_ops = {
1178         .start  = input_devices_seq_start,
1179         .next   = input_devices_seq_next,
1180         .stop   = input_seq_stop,
1181         .show   = input_devices_seq_show,
1182 };
1183 
1184 static int input_proc_devices_open(struct inode *inode, struct file *file)
1185 {
1186         return seq_open(file, &input_devices_seq_ops);
1187 }
1188 
1189 static const struct file_operations input_devices_fileops = {
1190         .owner          = THIS_MODULE,
1191         .open           = input_proc_devices_open,
1192         .poll           = input_proc_devices_poll,
1193         .read           = seq_read,
1194         .llseek         = seq_lseek,
1195         .release        = seq_release,
1196 };
1197 
1198 static void *input_handlers_seq_start(struct seq_file *seq, loff_t *pos)
1199 {
1200         union input_seq_state *state = (union input_seq_state *)&seq->private;
1201         int error;
1202 
1203         /* We need to fit into seq->private pointer */
1204         BUILD_BUG_ON(sizeof(union input_seq_state) != sizeof(seq->private));
1205 
1206         error = mutex_lock_interruptible(&input_mutex);
1207         if (error) {
1208                 state->mutex_acquired = false;
1209                 return ERR_PTR(error);
1210         }
1211 
1212         state->mutex_acquired = true;
1213         state->pos = *pos;
1214 
1215         return seq_list_start(&input_handler_list, *pos);
1216 }
1217 
1218 static void *input_handlers_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1219 {
1220         union input_seq_state *state = (union input_seq_state *)&seq->private;
1221 
1222         state->pos = *pos + 1;
1223         return seq_list_next(v, &input_handler_list, pos);
1224 }
1225 
1226 static int input_handlers_seq_show(struct seq_file *seq, void *v)
1227 {
1228         struct input_handler *handler = container_of(v, struct input_handler, node);
1229         union input_seq_state *state = (union input_seq_state *)&seq->private;
1230 
1231         seq_printf(seq, "N: Number=%u Name=%s", state->pos, handler->name);
1232         if (handler->filter)
1233                 seq_puts(seq, " (filter)");
1234         if (handler->legacy_minors)
1235                 seq_printf(seq, " Minor=%d", handler->minor);
1236         seq_putc(seq, '\n');
1237 
1238         return 0;
1239 }
1240 
1241 static const struct seq_operations input_handlers_seq_ops = {
1242         .start  = input_handlers_seq_start,
1243         .next   = input_handlers_seq_next,
1244         .stop   = input_seq_stop,
1245         .show   = input_handlers_seq_show,
1246 };
1247 
1248 static int input_proc_handlers_open(struct inode *inode, struct file *file)
1249 {
1250         return seq_open(file, &input_handlers_seq_ops);
1251 }
1252 
1253 static const struct file_operations input_handlers_fileops = {
1254         .owner          = THIS_MODULE,
1255         .open           = input_proc_handlers_open,
1256         .read           = seq_read,
1257         .llseek         = seq_lseek,
1258         .release        = seq_release,
1259 };
1260 
1261 static int __init input_proc_init(void)
1262 {
1263         struct proc_dir_entry *entry;
1264 
1265         proc_bus_input_dir = proc_mkdir("bus/input", NULL);
1266         if (!proc_bus_input_dir)
1267                 return -ENOMEM;
1268 
1269         entry = proc_create("devices", 0, proc_bus_input_dir,
1270                             &input_devices_fileops);
1271         if (!entry)
1272                 goto fail1;
1273 
1274         entry = proc_create("handlers", 0, proc_bus_input_dir,
1275                             &input_handlers_fileops);
1276         if (!entry)
1277                 goto fail2;
1278 
1279         return 0;
1280 
1281  fail2: remove_proc_entry("devices", proc_bus_input_dir);
1282  fail1: remove_proc_entry("bus/input", NULL);
1283         return -ENOMEM;
1284 }
1285 
1286 static void input_proc_exit(void)
1287 {
1288         remove_proc_entry("devices", proc_bus_input_dir);
1289         remove_proc_entry("handlers", proc_bus_input_dir);
1290         remove_proc_entry("bus/input", NULL);
1291 }
1292 
1293 #else /* !CONFIG_PROC_FS */
1294 static inline void input_wakeup_procfs_readers(void) { }
1295 static inline int input_proc_init(void) { return 0; }
1296 static inline void input_proc_exit(void) { }
1297 #endif
1298 
1299 #define INPUT_DEV_STRING_ATTR_SHOW(name)                                \
1300 static ssize_t input_dev_show_##name(struct device *dev,                \
1301                                      struct device_attribute *attr,     \
1302                                      char *buf)                         \
1303 {                                                                       \
1304         struct input_dev *input_dev = to_input_dev(dev);                \
1305                                                                         \
1306         return scnprintf(buf, PAGE_SIZE, "%s\n",                        \
1307                          input_dev->name ? input_dev->name : "");       \
1308 }                                                                       \
1309 static DEVICE_ATTR(name, S_IRUGO, input_dev_show_##name, NULL)
1310 
1311 INPUT_DEV_STRING_ATTR_SHOW(name);
1312 INPUT_DEV_STRING_ATTR_SHOW(phys);
1313 INPUT_DEV_STRING_ATTR_SHOW(uniq);
1314 
1315 static int input_print_modalias_bits(char *buf, int size,
1316                                      char name, unsigned long *bm,
1317                                      unsigned int min_bit, unsigned int max_bit)
1318 {
1319         int len = 0, i;
1320 
1321         len += snprintf(buf, max(size, 0), "%c", name);
1322         for (i = min_bit; i < max_bit; i++)
1323                 if (bm[BIT_WORD(i)] & BIT_MASK(i))
1324                         len += snprintf(buf + len, max(size - len, 0), "%X,", i);
1325         return len;
1326 }
1327 
1328 static int input_print_modalias(char *buf, int size, struct input_dev *id,
1329                                 int add_cr)
1330 {
1331         int len;
1332 
1333         len = snprintf(buf, max(size, 0),
1334                        "input:b%04Xv%04Xp%04Xe%04X-",
1335                        id->id.bustype, id->id.vendor,
1336                        id->id.product, id->id.version);
1337 
1338         len += input_print_modalias_bits(buf + len, size - len,
1339                                 'e', id->evbit, 0, EV_MAX);
1340         len += input_print_modalias_bits(buf + len, size - len,
1341                                 'k', id->keybit, KEY_MIN_INTERESTING, KEY_MAX);
1342         len += input_print_modalias_bits(buf + len, size - len,
1343                                 'r', id->relbit, 0, REL_MAX);
1344         len += input_print_modalias_bits(buf + len, size - len,
1345                                 'a', id->absbit, 0, ABS_MAX);
1346         len += input_print_modalias_bits(buf + len, size - len,
1347                                 'm', id->mscbit, 0, MSC_MAX);
1348         len += input_print_modalias_bits(buf + len, size - len,
1349                                 'l', id->ledbit, 0, LED_MAX);
1350         len += input_print_modalias_bits(buf + len, size - len,
1351                                 's', id->sndbit, 0, SND_MAX);
1352         len += input_print_modalias_bits(buf + len, size - len,
1353                                 'f', id->ffbit, 0, FF_MAX);
1354         len += input_print_modalias_bits(buf + len, size - len,
1355                                 'w', id->swbit, 0, SW_MAX);
1356 
1357         if (add_cr)
1358                 len += snprintf(buf + len, max(size - len, 0), "\n");
1359 
1360         return len;
1361 }
1362 
1363 static ssize_t input_dev_show_modalias(struct device *dev,
1364                                        struct device_attribute *attr,
1365                                        char *buf)
1366 {
1367         struct input_dev *id = to_input_dev(dev);
1368         ssize_t len;
1369 
1370         len = input_print_modalias(buf, PAGE_SIZE, id, 1);
1371 
1372         return min_t(int, len, PAGE_SIZE);
1373 }
1374 static DEVICE_ATTR(modalias, S_IRUGO, input_dev_show_modalias, NULL);
1375 
1376 static int input_print_bitmap(char *buf, int buf_size, unsigned long *bitmap,
1377                               int max, int add_cr);
1378 
1379 static ssize_t input_dev_show_properties(struct device *dev,
1380                                          struct device_attribute *attr,
1381                                          char *buf)
1382 {
1383         struct input_dev *input_dev = to_input_dev(dev);
1384         int len = input_print_bitmap(buf, PAGE_SIZE, input_dev->propbit,
1385                                      INPUT_PROP_MAX, true);
1386         return min_t(int, len, PAGE_SIZE);
1387 }
1388 static DEVICE_ATTR(properties, S_IRUGO, input_dev_show_properties, NULL);
1389 
1390 static struct attribute *input_dev_attrs[] = {
1391         &dev_attr_name.attr,
1392         &dev_attr_phys.attr,
1393         &dev_attr_uniq.attr,
1394         &dev_attr_modalias.attr,
1395         &dev_attr_properties.attr,
1396         NULL
1397 };
1398 
1399 static struct attribute_group input_dev_attr_group = {
1400         .attrs  = input_dev_attrs,
1401 };
1402 
1403 #define INPUT_DEV_ID_ATTR(name)                                         \
1404 static ssize_t input_dev_show_id_##name(struct device *dev,             \
1405                                         struct device_attribute *attr,  \
1406                                         char *buf)                      \
1407 {                                                                       \
1408         struct input_dev *input_dev = to_input_dev(dev);                \
1409         return scnprintf(buf, PAGE_SIZE, "%04x\n", input_dev->id.name); \
1410 }                                                                       \
1411 static DEVICE_ATTR(name, S_IRUGO, input_dev_show_id_##name, NULL)
1412 
1413 INPUT_DEV_ID_ATTR(bustype);
1414 INPUT_DEV_ID_ATTR(vendor);
1415 INPUT_DEV_ID_ATTR(product);
1416 INPUT_DEV_ID_ATTR(version);
1417 
1418 static struct attribute *input_dev_id_attrs[] = {
1419         &dev_attr_bustype.attr,
1420         &dev_attr_vendor.attr,
1421         &dev_attr_product.attr,
1422         &dev_attr_version.attr,
1423         NULL
1424 };
1425 
1426 static struct attribute_group input_dev_id_attr_group = {
1427         .name   = "id",
1428         .attrs  = input_dev_id_attrs,
1429 };
1430 
1431 static int input_print_bitmap(char *buf, int buf_size, unsigned long *bitmap,
1432                               int max, int add_cr)
1433 {
1434         int i;
1435         int len = 0;
1436         bool skip_empty = true;
1437 
1438         for (i = BITS_TO_LONGS(max) - 1; i >= 0; i--) {
1439                 len += input_bits_to_string(buf + len, max(buf_size - len, 0),
1440                                             bitmap[i], skip_empty);
1441                 if (len) {
1442                         skip_empty = false;
1443                         if (i > 0)
1444                                 len += snprintf(buf + len, max(buf_size - len, 0), " ");
1445                 }
1446         }
1447 
1448         /*
1449          * If no output was produced print a single 0.
1450          */
1451         if (len == 0)
1452                 len = snprintf(buf, buf_size, "%d", 0);
1453 
1454         if (add_cr)
1455                 len += snprintf(buf + len, max(buf_size - len, 0), "\n");
1456 
1457         return len;
1458 }
1459 
1460 #define INPUT_DEV_CAP_ATTR(ev, bm)                                      \
1461 static ssize_t input_dev_show_cap_##bm(struct device *dev,              \
1462                                        struct device_attribute *attr,   \
1463                                        char *buf)                       \
1464 {                                                                       \
1465         struct input_dev *input_dev = to_input_dev(dev);                \
1466         int len = input_print_bitmap(buf, PAGE_SIZE,                    \
1467                                      input_dev->bm##bit, ev##_MAX,      \
1468                                      true);                             \
1469         return min_t(int, len, PAGE_SIZE);                              \
1470 }                                                                       \
1471 static DEVICE_ATTR(bm, S_IRUGO, input_dev_show_cap_##bm, NULL)
1472 
1473 INPUT_DEV_CAP_ATTR(EV, ev);
1474 INPUT_DEV_CAP_ATTR(KEY, key);
1475 INPUT_DEV_CAP_ATTR(REL, rel);
1476 INPUT_DEV_CAP_ATTR(ABS, abs);
1477 INPUT_DEV_CAP_ATTR(MSC, msc);
1478 INPUT_DEV_CAP_ATTR(LED, led);
1479 INPUT_DEV_CAP_ATTR(SND, snd);
1480 INPUT_DEV_CAP_ATTR(FF, ff);
1481 INPUT_DEV_CAP_ATTR(SW, sw);
1482 
1483 static struct attribute *input_dev_caps_attrs[] = {
1484         &dev_attr_ev.attr,
1485         &dev_attr_key.attr,
1486         &dev_attr_rel.attr,
1487         &dev_attr_abs.attr,
1488         &dev_attr_msc.attr,
1489         &dev_attr_led.attr,
1490         &dev_attr_snd.attr,
1491         &dev_attr_ff.attr,
1492         &dev_attr_sw.attr,
1493         NULL
1494 };
1495 
1496 static struct attribute_group input_dev_caps_attr_group = {
1497         .name   = "capabilities",
1498         .attrs  = input_dev_caps_attrs,
1499 };
1500 
1501 static const struct attribute_group *input_dev_attr_groups[] = {
1502         &input_dev_attr_group,
1503         &input_dev_id_attr_group,
1504         &input_dev_caps_attr_group,
1505         NULL
1506 };
1507 
1508 static void input_dev_release(struct device *device)
1509 {
1510         struct input_dev *dev = to_input_dev(device);
1511 
1512         input_ff_destroy(dev);
1513         input_mt_destroy_slots(dev);
1514         kfree(dev->absinfo);
1515         kfree(dev->vals);
1516         kfree(dev);
1517 
1518         module_put(THIS_MODULE);
1519 }
1520 
1521 /*
1522  * Input uevent interface - loading event handlers based on
1523  * device bitfields.
1524  */
1525 static int input_add_uevent_bm_var(struct kobj_uevent_env *env,
1526                                    const char *name, unsigned long *bitmap, int max)
1527 {
1528         int len;
1529 
1530         if (add_uevent_var(env, "%s", name))
1531                 return -ENOMEM;
1532 
1533         len = input_print_bitmap(&env->buf[env->buflen - 1],
1534                                  sizeof(env->buf) - env->buflen,
1535                                  bitmap, max, false);
1536         if (len >= (sizeof(env->buf) - env->buflen))
1537                 return -ENOMEM;
1538 
1539         env->buflen += len;
1540         return 0;
1541 }
1542 
1543 static int input_add_uevent_modalias_var(struct kobj_uevent_env *env,
1544                                          struct input_dev *dev)
1545 {
1546         int len;
1547 
1548         if (add_uevent_var(env, "MODALIAS="))
1549                 return -ENOMEM;
1550 
1551         len = input_print_modalias(&env->buf[env->buflen - 1],
1552                                    sizeof(env->buf) - env->buflen,
1553                                    dev, 0);
1554         if (len >= (sizeof(env->buf) - env->buflen))
1555                 return -ENOMEM;
1556 
1557         env->buflen += len;
1558         return 0;
1559 }
1560 
1561 #define INPUT_ADD_HOTPLUG_VAR(fmt, val...)                              \
1562         do {                                                            \
1563                 int err = add_uevent_var(env, fmt, val);                \
1564                 if (err)                                                \
1565                         return err;                                     \
1566         } while (0)
1567 
1568 #define INPUT_ADD_HOTPLUG_BM_VAR(name, bm, max)                         \
1569         do {                                                            \
1570                 int err = input_add_uevent_bm_var(env, name, bm, max);  \
1571                 if (err)                                                \
1572                         return err;                                     \
1573         } while (0)
1574 
1575 #define INPUT_ADD_HOTPLUG_MODALIAS_VAR(dev)                             \
1576         do {                                                            \
1577                 int err = input_add_uevent_modalias_var(env, dev);      \
1578                 if (err)                                                \
1579                         return err;                                     \
1580         } while (0)
1581 
1582 static int input_dev_uevent(struct device *device, struct kobj_uevent_env *env)
1583 {
1584         struct input_dev *dev = to_input_dev(device);
1585 
1586         INPUT_ADD_HOTPLUG_VAR("PRODUCT=%x/%x/%x/%x",
1587                                 dev->id.bustype, dev->id.vendor,
1588                                 dev->id.product, dev->id.version);
1589         if (dev->name)
1590                 INPUT_ADD_HOTPLUG_VAR("NAME=\"%s\"", dev->name);
1591         if (dev->phys)
1592                 INPUT_ADD_HOTPLUG_VAR("PHYS=\"%s\"", dev->phys);
1593         if (dev->uniq)
1594                 INPUT_ADD_HOTPLUG_VAR("UNIQ=\"%s\"", dev->uniq);
1595 
1596         INPUT_ADD_HOTPLUG_BM_VAR("PROP=", dev->propbit, INPUT_PROP_MAX);
1597 
1598         INPUT_ADD_HOTPLUG_BM_VAR("EV=", dev->evbit, EV_MAX);
1599         if (test_bit(EV_KEY, dev->evbit))
1600                 INPUT_ADD_HOTPLUG_BM_VAR("KEY=", dev->keybit, KEY_MAX);
1601         if (test_bit(EV_REL, dev->evbit))
1602                 INPUT_ADD_HOTPLUG_BM_VAR("REL=", dev->relbit, REL_MAX);
1603         if (test_bit(EV_ABS, dev->evbit))
1604                 INPUT_ADD_HOTPLUG_BM_VAR("ABS=", dev->absbit, ABS_MAX);
1605         if (test_bit(EV_MSC, dev->evbit))
1606                 INPUT_ADD_HOTPLUG_BM_VAR("MSC=", dev->mscbit, MSC_MAX);
1607         if (test_bit(EV_LED, dev->evbit))
1608                 INPUT_ADD_HOTPLUG_BM_VAR("LED=", dev->ledbit, LED_MAX);
1609         if (test_bit(EV_SND, dev->evbit))
1610                 INPUT_ADD_HOTPLUG_BM_VAR("SND=", dev->sndbit, SND_MAX);
1611         if (test_bit(EV_FF, dev->evbit))
1612                 INPUT_ADD_HOTPLUG_BM_VAR("FF=", dev->ffbit, FF_MAX);
1613         if (test_bit(EV_SW, dev->evbit))
1614                 INPUT_ADD_HOTPLUG_BM_VAR("SW=", dev->swbit, SW_MAX);
1615 
1616         INPUT_ADD_HOTPLUG_MODALIAS_VAR(dev);
1617 
1618         return 0;
1619 }
1620 
1621 #define INPUT_DO_TOGGLE(dev, type, bits, on)                            \
1622         do {                                                            \
1623                 int i;                                                  \
1624                 bool active;                                            \
1625                                                                         \
1626                 if (!test_bit(EV_##type, dev->evbit))                   \
1627                         break;                                          \
1628                                                                         \
1629                 for (i = 0; i < type##_MAX; i++) {                      \
1630                         if (!test_bit(i, dev->bits##bit))               \
1631                                 continue;                               \
1632                                                                         \
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 (i = 0; i < ABS_CNT; i++) {
1985                         if (test_bit(i, dev->absbit)) {
1986                                 if (input_is_mt_axis(i))
1987                                         events += mt_slots;
1988                                 else
1989                                         events++;
1990                         }
1991                 }
1992         }
1993 
1994         if (test_bit(EV_REL, dev->evbit)) {
1995                 for (i = 0; i < REL_CNT; i++)
1996                         if (test_bit(i, dev->relbit))
1997                                 events++;
1998         }
1999 
2000         /* Make room for KEY and MSC events */
2001         events += 7;
2002 
2003         return events;
2004 }
2005 
2006 #define INPUT_CLEANSE_BITMASK(dev, type, bits)                          \
2007         do {                                                            \
2008                 if (!test_bit(EV_##type, dev->evbit))                   \
2009                         memset(dev->bits##bit, 0,                       \
2010                                 sizeof(dev->bits##bit));                \
2011         } while (0)
2012 
2013 static void input_cleanse_bitmasks(struct input_dev *dev)
2014 {
2015         INPUT_CLEANSE_BITMASK(dev, KEY, key);
2016         INPUT_CLEANSE_BITMASK(dev, REL, rel);
2017         INPUT_CLEANSE_BITMASK(dev, ABS, abs);
2018         INPUT_CLEANSE_BITMASK(dev, MSC, msc);
2019         INPUT_CLEANSE_BITMASK(dev, LED, led);
2020         INPUT_CLEANSE_BITMASK(dev, SND, snd);
2021         INPUT_CLEANSE_BITMASK(dev, FF, ff);
2022         INPUT_CLEANSE_BITMASK(dev, SW, sw);
2023 }
2024 
2025 static void __input_unregister_device(struct input_dev *dev)
2026 {
2027         struct input_handle *handle, *next;
2028 
2029         input_disconnect_device(dev);
2030 
2031         mutex_lock(&input_mutex);
2032 
2033         list_for_each_entry_safe(handle, next, &dev->h_list, d_node)
2034                 handle->handler->disconnect(handle);
2035         WARN_ON(!list_empty(&dev->h_list));
2036 
2037         del_timer_sync(&dev->timer);
2038         list_del_init(&dev->node);
2039 
2040         input_wakeup_procfs_readers();
2041 
2042         mutex_unlock(&input_mutex);
2043 
2044         device_del(&dev->dev);
2045 }
2046 
2047 static void devm_input_device_unregister(struct device *dev, void *res)
2048 {
2049         struct input_devres *devres = res;
2050         struct input_dev *input = devres->input;
2051 
2052         dev_dbg(dev, "%s: unregistering device %s\n",
2053                 __func__, dev_name(&input->dev));
2054         __input_unregister_device(input);
2055 }
2056 
2057 /**
2058  * input_register_device - register device with input core
2059  * @dev: device to be registered
2060  *
2061  * This function registers device with input core. The device must be
2062  * allocated with input_allocate_device() and all it's capabilities
2063  * set up before registering.
2064  * If function fails the device must be freed with input_free_device().
2065  * Once device has been successfully registered it can be unregistered
2066  * with input_unregister_device(); input_free_device() should not be
2067  * called in this case.
2068  *
2069  * Note that this function is also used to register managed input devices
2070  * (ones allocated with devm_input_allocate_device()). Such managed input
2071  * devices need not be explicitly unregistered or freed, their tear down
2072  * is controlled by the devres infrastructure. It is also worth noting
2073  * that tear down of managed input devices is internally a 2-step process:
2074  * registered managed input device is first unregistered, but stays in
2075  * memory and can still handle input_event() calls (although events will
2076  * not be delivered anywhere). The freeing of managed input device will
2077  * happen later, when devres stack is unwound to the point where device
2078  * allocation was made.
2079  */
2080 int input_register_device(struct input_dev *dev)
2081 {
2082         struct input_devres *devres = NULL;
2083         struct input_handler *handler;
2084         unsigned int packet_size;
2085         const char *path;
2086         int error;
2087 
2088         if (dev->devres_managed) {
2089                 devres = devres_alloc(devm_input_device_unregister,
2090                                       sizeof(struct input_devres), GFP_KERNEL);
2091                 if (!devres)
2092                         return -ENOMEM;
2093 
2094                 devres->input = dev;
2095         }
2096 
2097         /* Every input device generates EV_SYN/SYN_REPORT events. */
2098         __set_bit(EV_SYN, dev->evbit);
2099 
2100         /* KEY_RESERVED is not supposed to be transmitted to userspace. */
2101         __clear_bit(KEY_RESERVED, dev->keybit);
2102 
2103         /* Make sure that bitmasks not mentioned in dev->evbit are clean. */
2104         input_cleanse_bitmasks(dev);
2105 
2106         packet_size = input_estimate_events_per_packet(dev);
2107         if (dev->hint_events_per_packet < packet_size)
2108                 dev->hint_events_per_packet = packet_size;
2109 
2110         dev->max_vals = dev->hint_events_per_packet + 2;
2111         dev->vals = kcalloc(dev->max_vals, sizeof(*dev->vals), GFP_KERNEL);
2112         if (!dev->vals) {
2113                 error = -ENOMEM;
2114                 goto err_devres_free;
2115         }
2116 
2117         /*
2118          * If delay and period are pre-set by the driver, then autorepeating
2119          * is handled by the driver itself and we don't do it in input.c.
2120          */
2121         if (!dev->rep[REP_DELAY] && !dev->rep[REP_PERIOD]) {
2122                 dev->timer.data = (long) dev;
2123                 dev->timer.function = input_repeat_key;
2124                 dev->rep[REP_DELAY] = 250;
2125                 dev->rep[REP_PERIOD] = 33;
2126         }
2127 
2128         if (!dev->getkeycode)
2129                 dev->getkeycode = input_default_getkeycode;
2130 
2131         if (!dev->setkeycode)
2132                 dev->setkeycode = input_default_setkeycode;
2133 
2134         error = device_add(&dev->dev);
2135         if (error)
2136                 goto err_free_vals;
2137 
2138         path = kobject_get_path(&dev->dev.kobj, GFP_KERNEL);
2139         pr_info("%s as %s\n",
2140                 dev->name ? dev->name : "Unspecified device",
2141                 path ? path : "N/A");
2142         kfree(path);
2143 
2144         error = mutex_lock_interruptible(&input_mutex);
2145         if (error)
2146                 goto err_device_del;
2147 
2148         list_add_tail(&dev->node, &input_dev_list);
2149 
2150         list_for_each_entry(handler, &input_handler_list, node)
2151                 input_attach_handler(dev, handler);
2152 
2153         input_wakeup_procfs_readers();
2154 
2155         mutex_unlock(&input_mutex);
2156 
2157         if (dev->devres_managed) {
2158                 dev_dbg(dev->dev.parent, "%s: registering %s with devres.\n",
2159                         __func__, dev_name(&dev->dev));
2160                 devres_add(dev->dev.parent, devres);
2161         }
2162         return 0;
2163 
2164 err_device_del:
2165         device_del(&dev->dev);
2166 err_free_vals:
2167         kfree(dev->vals);
2168         dev->vals = NULL;
2169 err_devres_free:
2170         devres_free(devres);
2171         return error;
2172 }
2173 EXPORT_SYMBOL(input_register_device);
2174 
2175 /**
2176  * input_unregister_device - unregister previously registered device
2177  * @dev: device to be unregistered
2178  *
2179  * This function unregisters an input device. Once device is unregistered
2180  * the caller should not try to access it as it may get freed at any moment.
2181  */
2182 void input_unregister_device(struct input_dev *dev)
2183 {
2184         if (dev->devres_managed) {
2185                 WARN_ON(devres_destroy(dev->dev.parent,
2186                                         devm_input_device_unregister,
2187                                         devm_input_device_match,
2188                                         dev));
2189                 __input_unregister_device(dev);
2190                 /*
2191                  * We do not do input_put_device() here because it will be done
2192                  * when 2nd devres fires up.
2193                  */
2194         } else {
2195                 __input_unregister_device(dev);
2196                 input_put_device(dev);
2197         }
2198 }
2199 EXPORT_SYMBOL(input_unregister_device);
2200 
2201 /**
2202  * input_register_handler - register a new input handler
2203  * @handler: handler to be registered
2204  *
2205  * This function registers a new input handler (interface) for input
2206  * devices in the system and attaches it to all input devices that
2207  * are compatible with the handler.
2208  */
2209 int input_register_handler(struct input_handler *handler)
2210 {
2211         struct input_dev *dev;
2212         int error;
2213 
2214         error = mutex_lock_interruptible(&input_mutex);
2215         if (error)
2216                 return error;
2217 
2218         INIT_LIST_HEAD(&handler->h_list);
2219 
2220         list_add_tail(&handler->node, &input_handler_list);
2221 
2222         list_for_each_entry(dev, &input_dev_list, node)
2223                 input_attach_handler(dev, handler);
2224 
2225         input_wakeup_procfs_readers();
2226 
2227         mutex_unlock(&input_mutex);
2228         return 0;
2229 }
2230 EXPORT_SYMBOL(input_register_handler);
2231 
2232 /**
2233  * input_unregister_handler - unregisters an input handler
2234  * @handler: handler to be unregistered
2235  *
2236  * This function disconnects a handler from its input devices and
2237  * removes it from lists of known handlers.
2238  */
2239 void input_unregister_handler(struct input_handler *handler)
2240 {
2241         struct input_handle *handle, *next;
2242 
2243         mutex_lock(&input_mutex);
2244 
2245         list_for_each_entry_safe(handle, next, &handler->h_list, h_node)
2246                 handler->disconnect(handle);
2247         WARN_ON(!list_empty(&handler->h_list));
2248 
2249         list_del_init(&handler->node);
2250 
2251         input_wakeup_procfs_readers();
2252 
2253         mutex_unlock(&input_mutex);
2254 }
2255 EXPORT_SYMBOL(input_unregister_handler);
2256 
2257 /**
2258  * input_handler_for_each_handle - handle iterator
2259  * @handler: input handler to iterate
2260  * @data: data for the callback
2261  * @fn: function to be called for each handle
2262  *
2263  * Iterate over @bus's list of devices, and call @fn for each, passing
2264  * it @data and stop when @fn returns a non-zero value. The function is
2265  * using RCU to traverse the list and therefore may be usind in atonic
2266  * contexts. The @fn callback is invoked from RCU critical section and
2267  * thus must not sleep.
2268  */
2269 int input_handler_for_each_handle(struct input_handler *handler, void *data,
2270                                   int (*fn)(struct input_handle *, void *))
2271 {
2272         struct input_handle *handle;
2273         int retval = 0;
2274 
2275         rcu_read_lock();
2276 
2277         list_for_each_entry_rcu(handle, &handler->h_list, h_node) {
2278                 retval = fn(handle, data);
2279                 if (retval)
2280                         break;
2281         }
2282 
2283         rcu_read_unlock();
2284 
2285         return retval;
2286 }
2287 EXPORT_SYMBOL(input_handler_for_each_handle);
2288 
2289 /**
2290  * input_register_handle - register a new input handle
2291  * @handle: handle to register
2292  *
2293  * This function puts a new input handle onto device's
2294  * and handler's lists so that events can flow through
2295  * it once it is opened using input_open_device().
2296  *
2297  * This function is supposed to be called from handler's
2298  * connect() method.
2299  */
2300 int input_register_handle(struct input_handle *handle)
2301 {
2302         struct input_handler *handler = handle->handler;
2303         struct input_dev *dev = handle->dev;
2304         int error;
2305 
2306         /*
2307          * We take dev->mutex here to prevent race with
2308          * input_release_device().
2309          */
2310         error = mutex_lock_interruptible(&dev->mutex);
2311         if (error)
2312                 return error;
2313 
2314         /*
2315          * Filters go to the head of the list, normal handlers
2316          * to the tail.
2317          */
2318         if (handler->filter)
2319                 list_add_rcu(&handle->d_node, &dev->h_list);
2320         else
2321                 list_add_tail_rcu(&handle->d_node, &dev->h_list);
2322 
2323         mutex_unlock(&dev->mutex);
2324 
2325         /*
2326          * Since we are supposed to be called from ->connect()
2327          * which is mutually exclusive with ->disconnect()
2328          * we can't be racing with input_unregister_handle()
2329          * and so separate lock is not needed here.
2330          */
2331         list_add_tail_rcu(&handle->h_node, &handler->h_list);
2332 
2333         if (handler->start)
2334                 handler->start(handle);
2335 
2336         return 0;
2337 }
2338 EXPORT_SYMBOL(input_register_handle);
2339 
2340 /**
2341  * input_unregister_handle - unregister an input handle
2342  * @handle: handle to unregister
2343  *
2344  * This function removes input handle from device's
2345  * and handler's lists.
2346  *
2347  * This function is supposed to be called from handler's
2348  * disconnect() method.
2349  */
2350 void input_unregister_handle(struct input_handle *handle)
2351 {
2352         struct input_dev *dev = handle->dev;
2353 
2354         list_del_rcu(&handle->h_node);
2355 
2356         /*
2357          * Take dev->mutex to prevent race with input_release_device().
2358          */
2359         mutex_lock(&dev->mutex);
2360         list_del_rcu(&handle->d_node);
2361         mutex_unlock(&dev->mutex);
2362 
2363         synchronize_rcu();
2364 }
2365 EXPORT_SYMBOL(input_unregister_handle);
2366 
2367 /**
2368  * input_get_new_minor - allocates a new input minor number
2369  * @legacy_base: beginning or the legacy range to be searched
2370  * @legacy_num: size of legacy range
2371  * @allow_dynamic: whether we can also take ID from the dynamic range
2372  *
2373  * This function allocates a new device minor for from input major namespace.
2374  * Caller can request legacy minor by specifying @legacy_base and @legacy_num
2375  * parameters and whether ID can be allocated from dynamic range if there are
2376  * no free IDs in legacy range.
2377  */
2378 int input_get_new_minor(int legacy_base, unsigned int legacy_num,
2379                         bool allow_dynamic)
2380 {
2381         /*
2382          * This function should be called from input handler's ->connect()
2383          * methods, which are serialized with input_mutex, so no additional
2384          * locking is needed here.
2385          */
2386         if (legacy_base >= 0) {
2387                 int minor = ida_simple_get(&input_ida,
2388                                            legacy_base,
2389                                            legacy_base + legacy_num,
2390                                            GFP_KERNEL);
2391                 if (minor >= 0 || !allow_dynamic)
2392                         return minor;
2393         }
2394 
2395         return ida_simple_get(&input_ida,
2396                               INPUT_FIRST_DYNAMIC_DEV, INPUT_MAX_CHAR_DEVICES,
2397                               GFP_KERNEL);
2398 }
2399 EXPORT_SYMBOL(input_get_new_minor);
2400 
2401 /**
2402  * input_free_minor - release previously allocated minor
2403  * @minor: minor to be released
2404  *
2405  * This function releases previously allocated input minor so that it can be
2406  * reused later.
2407  */
2408 void input_free_minor(unsigned int minor)
2409 {
2410         ida_simple_remove(&input_ida, minor);
2411 }
2412 EXPORT_SYMBOL(input_free_minor);
2413 
2414 static int __init input_init(void)
2415 {
2416         int err;
2417 
2418         err = class_register(&input_class);
2419         if (err) {
2420                 pr_err("unable to register input_dev class\n");
2421                 return err;
2422         }
2423 
2424         err = input_proc_init();
2425         if (err)
2426                 goto fail1;
2427 
2428         err = register_chrdev_region(MKDEV(INPUT_MAJOR, 0),
2429                                      INPUT_MAX_CHAR_DEVICES, "input");
2430         if (err) {
2431                 pr_err("unable to register char major %d", INPUT_MAJOR);
2432                 goto fail2;
2433         }
2434 
2435         return 0;
2436 
2437  fail2: input_proc_exit();
2438  fail1: class_unregister(&input_class);
2439         return err;
2440 }
2441 
2442 static void __exit input_exit(void)
2443 {
2444         input_proc_exit();
2445         unregister_chrdev_region(MKDEV(INPUT_MAJOR, 0),
2446                                  INPUT_MAX_CHAR_DEVICES);
2447         class_unregister(&input_class);
2448 }
2449 
2450 subsys_initcall(input_init);
2451 module_exit(input_exit);
2452 

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