Version:  2.0.40 2.2.26 2.4.37 2.6.39 3.0 3.1 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

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

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