Version:  2.0.40 2.2.26 2.4.37 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 3.16 3.17

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

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