Version:  2.0.40 2.2.26 2.4.37 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 4.5 4.6 4.7 4.8

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

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