Version:  2.0.40 2.2.26 2.4.37 3.2 3.3 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

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

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