xref: /linux/drivers/input/input.c (revision cd354f1ae75e6466a7e31b727faede57a1f89ca5)
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 #include <linux/init.h>
14 #include <linux/smp_lock.h>
15 #include <linux/input.h>
16 #include <linux/module.h>
17 #include <linux/random.h>
18 #include <linux/major.h>
19 #include <linux/proc_fs.h>
20 #include <linux/seq_file.h>
21 #include <linux/interrupt.h>
22 #include <linux/poll.h>
23 #include <linux/device.h>
24 #include <linux/mutex.h>
25 
26 MODULE_AUTHOR("Vojtech Pavlik <vojtech@suse.cz>");
27 MODULE_DESCRIPTION("Input core");
28 MODULE_LICENSE("GPL");
29 
30 #define INPUT_DEVICES	256
31 
32 static LIST_HEAD(input_dev_list);
33 static LIST_HEAD(input_handler_list);
34 
35 static struct input_handler *input_table[8];
36 
37 /**
38  * input_event() - report new input event
39  * @dev: device that generated the event
40  * @type: type of the event
41  * @code: event code
42  * @value: value of the event
43  *
44  * This function should be used by drivers implementing various input devices
45  * See also input_inject_event()
46  */
47 void input_event(struct input_dev *dev, unsigned int type, unsigned int code, int value)
48 {
49 	struct input_handle *handle;
50 
51 	if (type > EV_MAX || !test_bit(type, dev->evbit))
52 		return;
53 
54 	add_input_randomness(type, code, value);
55 
56 	switch (type) {
57 
58 		case EV_SYN:
59 			switch (code) {
60 				case SYN_CONFIG:
61 					if (dev->event)
62 						dev->event(dev, type, code, value);
63 					break;
64 
65 				case SYN_REPORT:
66 					if (dev->sync)
67 						return;
68 					dev->sync = 1;
69 					break;
70 			}
71 			break;
72 
73 		case EV_KEY:
74 
75 			if (code > KEY_MAX || !test_bit(code, dev->keybit) || !!test_bit(code, dev->key) == value)
76 				return;
77 
78 			if (value == 2)
79 				break;
80 
81 			change_bit(code, dev->key);
82 
83 			if (test_bit(EV_REP, dev->evbit) && dev->rep[REP_PERIOD] && dev->rep[REP_DELAY] && dev->timer.data && value) {
84 				dev->repeat_key = code;
85 				mod_timer(&dev->timer, jiffies + msecs_to_jiffies(dev->rep[REP_DELAY]));
86 			}
87 
88 			break;
89 
90 		case EV_SW:
91 
92 			if (code > SW_MAX || !test_bit(code, dev->swbit) || !!test_bit(code, dev->sw) == value)
93 				return;
94 
95 			change_bit(code, dev->sw);
96 
97 			break;
98 
99 		case EV_ABS:
100 
101 			if (code > ABS_MAX || !test_bit(code, dev->absbit))
102 				return;
103 
104 			if (dev->absfuzz[code]) {
105 				if ((value > dev->abs[code] - (dev->absfuzz[code] >> 1)) &&
106 				    (value < dev->abs[code] + (dev->absfuzz[code] >> 1)))
107 					return;
108 
109 				if ((value > dev->abs[code] - dev->absfuzz[code]) &&
110 				    (value < dev->abs[code] + dev->absfuzz[code]))
111 					value = (dev->abs[code] * 3 + value) >> 2;
112 
113 				if ((value > dev->abs[code] - (dev->absfuzz[code] << 1)) &&
114 				    (value < dev->abs[code] + (dev->absfuzz[code] << 1)))
115 					value = (dev->abs[code] + value) >> 1;
116 			}
117 
118 			if (dev->abs[code] == value)
119 				return;
120 
121 			dev->abs[code] = value;
122 			break;
123 
124 		case EV_REL:
125 
126 			if (code > REL_MAX || !test_bit(code, dev->relbit) || (value == 0))
127 				return;
128 
129 			break;
130 
131 		case EV_MSC:
132 
133 			if (code > MSC_MAX || !test_bit(code, dev->mscbit))
134 				return;
135 
136 			if (dev->event)
137 				dev->event(dev, type, code, value);
138 
139 			break;
140 
141 		case EV_LED:
142 
143 			if (code > LED_MAX || !test_bit(code, dev->ledbit) || !!test_bit(code, dev->led) == value)
144 				return;
145 
146 			change_bit(code, dev->led);
147 
148 			if (dev->event)
149 				dev->event(dev, type, code, value);
150 
151 			break;
152 
153 		case EV_SND:
154 
155 			if (code > SND_MAX || !test_bit(code, dev->sndbit))
156 				return;
157 
158 			if (!!test_bit(code, dev->snd) != !!value)
159 				change_bit(code, dev->snd);
160 
161 			if (dev->event)
162 				dev->event(dev, type, code, value);
163 
164 			break;
165 
166 		case EV_REP:
167 
168 			if (code > REP_MAX || value < 0 || dev->rep[code] == value)
169 				return;
170 
171 			dev->rep[code] = value;
172 			if (dev->event)
173 				dev->event(dev, type, code, value);
174 
175 			break;
176 
177 		case EV_FF:
178 
179 			if (value < 0)
180 				return;
181 
182 			if (dev->event)
183 				dev->event(dev, type, code, value);
184 			break;
185 	}
186 
187 	if (type != EV_SYN)
188 		dev->sync = 0;
189 
190 	if (dev->grab)
191 		dev->grab->handler->event(dev->grab, type, code, value);
192 	else
193 		list_for_each_entry(handle, &dev->h_list, d_node)
194 			if (handle->open)
195 				handle->handler->event(handle, type, code, value);
196 }
197 EXPORT_SYMBOL(input_event);
198 
199 /**
200  * input_inject_event() - send input event from input handler
201  * @handle: input handle to send event through
202  * @type: type of the event
203  * @code: event code
204  * @value: value of the event
205  *
206  * Similar to input_event() but will ignore event if device is "grabbed" and handle
207  * injecting event is not the one that owns the device.
208  */
209 void input_inject_event(struct input_handle *handle, unsigned int type, unsigned int code, int value)
210 {
211 	if (!handle->dev->grab || handle->dev->grab == handle)
212 		input_event(handle->dev, type, code, value);
213 }
214 EXPORT_SYMBOL(input_inject_event);
215 
216 static void input_repeat_key(unsigned long data)
217 {
218 	struct input_dev *dev = (void *) data;
219 
220 	if (!test_bit(dev->repeat_key, dev->key))
221 		return;
222 
223 	input_event(dev, EV_KEY, dev->repeat_key, 2);
224 	input_sync(dev);
225 
226 	if (dev->rep[REP_PERIOD])
227 		mod_timer(&dev->timer, jiffies + msecs_to_jiffies(dev->rep[REP_PERIOD]));
228 }
229 
230 int input_grab_device(struct input_handle *handle)
231 {
232 	if (handle->dev->grab)
233 		return -EBUSY;
234 
235 	handle->dev->grab = handle;
236 	return 0;
237 }
238 EXPORT_SYMBOL(input_grab_device);
239 
240 void input_release_device(struct input_handle *handle)
241 {
242 	struct input_dev *dev = handle->dev;
243 
244 	if (dev->grab == handle) {
245 		dev->grab = NULL;
246 
247 		list_for_each_entry(handle, &dev->h_list, d_node)
248 			if (handle->handler->start)
249 				handle->handler->start(handle);
250 	}
251 }
252 EXPORT_SYMBOL(input_release_device);
253 
254 int input_open_device(struct input_handle *handle)
255 {
256 	struct input_dev *dev = handle->dev;
257 	int err;
258 
259 	err = mutex_lock_interruptible(&dev->mutex);
260 	if (err)
261 		return err;
262 
263 	handle->open++;
264 
265 	if (!dev->users++ && dev->open)
266 		err = dev->open(dev);
267 
268 	if (err)
269 		handle->open--;
270 
271 	mutex_unlock(&dev->mutex);
272 
273 	return err;
274 }
275 EXPORT_SYMBOL(input_open_device);
276 
277 int input_flush_device(struct input_handle* handle, struct file* file)
278 {
279 	if (handle->dev->flush)
280 		return handle->dev->flush(handle->dev, file);
281 
282 	return 0;
283 }
284 EXPORT_SYMBOL(input_flush_device);
285 
286 void input_close_device(struct input_handle *handle)
287 {
288 	struct input_dev *dev = handle->dev;
289 
290 	input_release_device(handle);
291 
292 	mutex_lock(&dev->mutex);
293 
294 	if (!--dev->users && dev->close)
295 		dev->close(dev);
296 	handle->open--;
297 
298 	mutex_unlock(&dev->mutex);
299 }
300 EXPORT_SYMBOL(input_close_device);
301 
302 static void input_link_handle(struct input_handle *handle)
303 {
304 	list_add_tail(&handle->d_node, &handle->dev->h_list);
305 	list_add_tail(&handle->h_node, &handle->handler->h_list);
306 }
307 
308 #define MATCH_BIT(bit, max) \
309 		for (i = 0; i < NBITS(max); i++) \
310 			if ((id->bit[i] & dev->bit[i]) != id->bit[i]) \
311 				break; \
312 		if (i != NBITS(max)) \
313 			continue;
314 
315 static const struct input_device_id *input_match_device(const struct input_device_id *id,
316 							struct input_dev *dev)
317 {
318 	int i;
319 
320 	for (; id->flags || id->driver_info; id++) {
321 
322 		if (id->flags & INPUT_DEVICE_ID_MATCH_BUS)
323 			if (id->bustype != dev->id.bustype)
324 				continue;
325 
326 		if (id->flags & INPUT_DEVICE_ID_MATCH_VENDOR)
327 			if (id->vendor != dev->id.vendor)
328 				continue;
329 
330 		if (id->flags & INPUT_DEVICE_ID_MATCH_PRODUCT)
331 			if (id->product != dev->id.product)
332 				continue;
333 
334 		if (id->flags & INPUT_DEVICE_ID_MATCH_VERSION)
335 			if (id->version != dev->id.version)
336 				continue;
337 
338 		MATCH_BIT(evbit,  EV_MAX);
339 		MATCH_BIT(keybit, KEY_MAX);
340 		MATCH_BIT(relbit, REL_MAX);
341 		MATCH_BIT(absbit, ABS_MAX);
342 		MATCH_BIT(mscbit, MSC_MAX);
343 		MATCH_BIT(ledbit, LED_MAX);
344 		MATCH_BIT(sndbit, SND_MAX);
345 		MATCH_BIT(ffbit,  FF_MAX);
346 		MATCH_BIT(swbit,  SW_MAX);
347 
348 		return id;
349 	}
350 
351 	return NULL;
352 }
353 
354 #ifdef CONFIG_PROC_FS
355 
356 static struct proc_dir_entry *proc_bus_input_dir;
357 static DECLARE_WAIT_QUEUE_HEAD(input_devices_poll_wait);
358 static int input_devices_state;
359 
360 static inline void input_wakeup_procfs_readers(void)
361 {
362 	input_devices_state++;
363 	wake_up(&input_devices_poll_wait);
364 }
365 
366 static unsigned int input_proc_devices_poll(struct file *file, poll_table *wait)
367 {
368 	int state = input_devices_state;
369 
370 	poll_wait(file, &input_devices_poll_wait, wait);
371 	if (state != input_devices_state)
372 		return POLLIN | POLLRDNORM;
373 
374 	return 0;
375 }
376 
377 static struct list_head *list_get_nth_element(struct list_head *list, loff_t *pos)
378 {
379 	struct list_head *node;
380 	loff_t i = 0;
381 
382 	list_for_each(node, list)
383 		if (i++ == *pos)
384 			return node;
385 
386 	return NULL;
387 }
388 
389 static struct list_head *list_get_next_element(struct list_head *list, struct list_head *element, loff_t *pos)
390 {
391 	if (element->next == list)
392 		return NULL;
393 
394 	++(*pos);
395 	return element->next;
396 }
397 
398 static void *input_devices_seq_start(struct seq_file *seq, loff_t *pos)
399 {
400 	/* acquire lock here ... Yes, we do need locking, I knowi, I know... */
401 
402 	return list_get_nth_element(&input_dev_list, pos);
403 }
404 
405 static void *input_devices_seq_next(struct seq_file *seq, void *v, loff_t *pos)
406 {
407 	return list_get_next_element(&input_dev_list, v, pos);
408 }
409 
410 static void input_devices_seq_stop(struct seq_file *seq, void *v)
411 {
412 	/* release lock here */
413 }
414 
415 static void input_seq_print_bitmap(struct seq_file *seq, const char *name,
416 				   unsigned long *bitmap, int max)
417 {
418 	int i;
419 
420 	for (i = NBITS(max) - 1; i > 0; i--)
421 		if (bitmap[i])
422 			break;
423 
424 	seq_printf(seq, "B: %s=", name);
425 	for (; i >= 0; i--)
426 		seq_printf(seq, "%lx%s", bitmap[i], i > 0 ? " " : "");
427 	seq_putc(seq, '\n');
428 }
429 
430 static int input_devices_seq_show(struct seq_file *seq, void *v)
431 {
432 	struct input_dev *dev = container_of(v, struct input_dev, node);
433 	const char *path = kobject_get_path(&dev->cdev.kobj, GFP_KERNEL);
434 	struct input_handle *handle;
435 
436 	seq_printf(seq, "I: Bus=%04x Vendor=%04x Product=%04x Version=%04x\n",
437 		   dev->id.bustype, dev->id.vendor, dev->id.product, dev->id.version);
438 
439 	seq_printf(seq, "N: Name=\"%s\"\n", dev->name ? dev->name : "");
440 	seq_printf(seq, "P: Phys=%s\n", dev->phys ? dev->phys : "");
441 	seq_printf(seq, "S: Sysfs=%s\n", path ? path : "");
442 	seq_printf(seq, "H: Handlers=");
443 
444 	list_for_each_entry(handle, &dev->h_list, d_node)
445 		seq_printf(seq, "%s ", handle->name);
446 	seq_putc(seq, '\n');
447 
448 	input_seq_print_bitmap(seq, "EV", dev->evbit, EV_MAX);
449 	if (test_bit(EV_KEY, dev->evbit))
450 		input_seq_print_bitmap(seq, "KEY", dev->keybit, KEY_MAX);
451 	if (test_bit(EV_REL, dev->evbit))
452 		input_seq_print_bitmap(seq, "REL", dev->relbit, REL_MAX);
453 	if (test_bit(EV_ABS, dev->evbit))
454 		input_seq_print_bitmap(seq, "ABS", dev->absbit, ABS_MAX);
455 	if (test_bit(EV_MSC, dev->evbit))
456 		input_seq_print_bitmap(seq, "MSC", dev->mscbit, MSC_MAX);
457 	if (test_bit(EV_LED, dev->evbit))
458 		input_seq_print_bitmap(seq, "LED", dev->ledbit, LED_MAX);
459 	if (test_bit(EV_SND, dev->evbit))
460 		input_seq_print_bitmap(seq, "SND", dev->sndbit, SND_MAX);
461 	if (test_bit(EV_FF, dev->evbit))
462 		input_seq_print_bitmap(seq, "FF", dev->ffbit, FF_MAX);
463 	if (test_bit(EV_SW, dev->evbit))
464 		input_seq_print_bitmap(seq, "SW", dev->swbit, SW_MAX);
465 
466 	seq_putc(seq, '\n');
467 
468 	kfree(path);
469 	return 0;
470 }
471 
472 static struct seq_operations input_devices_seq_ops = {
473 	.start	= input_devices_seq_start,
474 	.next	= input_devices_seq_next,
475 	.stop	= input_devices_seq_stop,
476 	.show	= input_devices_seq_show,
477 };
478 
479 static int input_proc_devices_open(struct inode *inode, struct file *file)
480 {
481 	return seq_open(file, &input_devices_seq_ops);
482 }
483 
484 static const struct file_operations input_devices_fileops = {
485 	.owner		= THIS_MODULE,
486 	.open		= input_proc_devices_open,
487 	.poll		= input_proc_devices_poll,
488 	.read		= seq_read,
489 	.llseek		= seq_lseek,
490 	.release	= seq_release,
491 };
492 
493 static void *input_handlers_seq_start(struct seq_file *seq, loff_t *pos)
494 {
495 	/* acquire lock here ... Yes, we do need locking, I knowi, I know... */
496 	seq->private = (void *)(unsigned long)*pos;
497 	return list_get_nth_element(&input_handler_list, pos);
498 }
499 
500 static void *input_handlers_seq_next(struct seq_file *seq, void *v, loff_t *pos)
501 {
502 	seq->private = (void *)(unsigned long)(*pos + 1);
503 	return list_get_next_element(&input_handler_list, v, pos);
504 }
505 
506 static void input_handlers_seq_stop(struct seq_file *seq, void *v)
507 {
508 	/* release lock here */
509 }
510 
511 static int input_handlers_seq_show(struct seq_file *seq, void *v)
512 {
513 	struct input_handler *handler = container_of(v, struct input_handler, node);
514 
515 	seq_printf(seq, "N: Number=%ld Name=%s",
516 		   (unsigned long)seq->private, handler->name);
517 	if (handler->fops)
518 		seq_printf(seq, " Minor=%d", handler->minor);
519 	seq_putc(seq, '\n');
520 
521 	return 0;
522 }
523 static struct seq_operations input_handlers_seq_ops = {
524 	.start	= input_handlers_seq_start,
525 	.next	= input_handlers_seq_next,
526 	.stop	= input_handlers_seq_stop,
527 	.show	= input_handlers_seq_show,
528 };
529 
530 static int input_proc_handlers_open(struct inode *inode, struct file *file)
531 {
532 	return seq_open(file, &input_handlers_seq_ops);
533 }
534 
535 static const struct file_operations input_handlers_fileops = {
536 	.owner		= THIS_MODULE,
537 	.open		= input_proc_handlers_open,
538 	.read		= seq_read,
539 	.llseek		= seq_lseek,
540 	.release	= seq_release,
541 };
542 
543 static int __init input_proc_init(void)
544 {
545 	struct proc_dir_entry *entry;
546 
547 	proc_bus_input_dir = proc_mkdir("input", proc_bus);
548 	if (!proc_bus_input_dir)
549 		return -ENOMEM;
550 
551 	proc_bus_input_dir->owner = THIS_MODULE;
552 
553 	entry = create_proc_entry("devices", 0, proc_bus_input_dir);
554 	if (!entry)
555 		goto fail1;
556 
557 	entry->owner = THIS_MODULE;
558 	entry->proc_fops = &input_devices_fileops;
559 
560 	entry = create_proc_entry("handlers", 0, proc_bus_input_dir);
561 	if (!entry)
562 		goto fail2;
563 
564 	entry->owner = THIS_MODULE;
565 	entry->proc_fops = &input_handlers_fileops;
566 
567 	return 0;
568 
569  fail2:	remove_proc_entry("devices", proc_bus_input_dir);
570  fail1: remove_proc_entry("input", proc_bus);
571 	return -ENOMEM;
572 }
573 
574 static void input_proc_exit(void)
575 {
576 	remove_proc_entry("devices", proc_bus_input_dir);
577 	remove_proc_entry("handlers", proc_bus_input_dir);
578 	remove_proc_entry("input", proc_bus);
579 }
580 
581 #else /* !CONFIG_PROC_FS */
582 static inline void input_wakeup_procfs_readers(void) { }
583 static inline int input_proc_init(void) { return 0; }
584 static inline void input_proc_exit(void) { }
585 #endif
586 
587 #define INPUT_DEV_STRING_ATTR_SHOW(name)					\
588 static ssize_t input_dev_show_##name(struct class_device *dev, char *buf)	\
589 {										\
590 	struct input_dev *input_dev = to_input_dev(dev);			\
591 	int retval;								\
592 										\
593 	retval = mutex_lock_interruptible(&input_dev->mutex);			\
594 	if (retval)								\
595 		return retval;							\
596 										\
597 	retval = scnprintf(buf, PAGE_SIZE,					\
598 			   "%s\n", input_dev->name ? input_dev->name : "");	\
599 										\
600 	mutex_unlock(&input_dev->mutex);					\
601 										\
602 	return retval;								\
603 }										\
604 static CLASS_DEVICE_ATTR(name, S_IRUGO, input_dev_show_##name, NULL);
605 
606 INPUT_DEV_STRING_ATTR_SHOW(name);
607 INPUT_DEV_STRING_ATTR_SHOW(phys);
608 INPUT_DEV_STRING_ATTR_SHOW(uniq);
609 
610 static int input_print_modalias_bits(char *buf, int size,
611 				     char name, unsigned long *bm,
612 				     unsigned int min_bit, unsigned int max_bit)
613 {
614 	int len = 0, i;
615 
616 	len += snprintf(buf, max(size, 0), "%c", name);
617 	for (i = min_bit; i < max_bit; i++)
618 		if (bm[LONG(i)] & BIT(i))
619 			len += snprintf(buf + len, max(size - len, 0), "%X,", i);
620 	return len;
621 }
622 
623 static int input_print_modalias(char *buf, int size, struct input_dev *id,
624 				int add_cr)
625 {
626 	int len;
627 
628 	len = snprintf(buf, max(size, 0),
629 		       "input:b%04Xv%04Xp%04Xe%04X-",
630 		       id->id.bustype, id->id.vendor,
631 		       id->id.product, id->id.version);
632 
633 	len += input_print_modalias_bits(buf + len, size - len,
634 				'e', id->evbit, 0, EV_MAX);
635 	len += input_print_modalias_bits(buf + len, size - len,
636 				'k', id->keybit, KEY_MIN_INTERESTING, KEY_MAX);
637 	len += input_print_modalias_bits(buf + len, size - len,
638 				'r', id->relbit, 0, REL_MAX);
639 	len += input_print_modalias_bits(buf + len, size - len,
640 				'a', id->absbit, 0, ABS_MAX);
641 	len += input_print_modalias_bits(buf + len, size - len,
642 				'm', id->mscbit, 0, MSC_MAX);
643 	len += input_print_modalias_bits(buf + len, size - len,
644 				'l', id->ledbit, 0, LED_MAX);
645 	len += input_print_modalias_bits(buf + len, size - len,
646 				's', id->sndbit, 0, SND_MAX);
647 	len += input_print_modalias_bits(buf + len, size - len,
648 				'f', id->ffbit, 0, FF_MAX);
649 	len += input_print_modalias_bits(buf + len, size - len,
650 				'w', id->swbit, 0, SW_MAX);
651 
652 	if (add_cr)
653 		len += snprintf(buf + len, max(size - len, 0), "\n");
654 
655 	return len;
656 }
657 
658 static ssize_t input_dev_show_modalias(struct class_device *dev, char *buf)
659 {
660 	struct input_dev *id = to_input_dev(dev);
661 	ssize_t len;
662 
663 	len = input_print_modalias(buf, PAGE_SIZE, id, 1);
664 
665 	return min_t(int, len, PAGE_SIZE);
666 }
667 static CLASS_DEVICE_ATTR(modalias, S_IRUGO, input_dev_show_modalias, NULL);
668 
669 static struct attribute *input_dev_attrs[] = {
670 	&class_device_attr_name.attr,
671 	&class_device_attr_phys.attr,
672 	&class_device_attr_uniq.attr,
673 	&class_device_attr_modalias.attr,
674 	NULL
675 };
676 
677 static struct attribute_group input_dev_attr_group = {
678 	.attrs	= input_dev_attrs,
679 };
680 
681 #define INPUT_DEV_ID_ATTR(name)							\
682 static ssize_t input_dev_show_id_##name(struct class_device *dev, char *buf)	\
683 {										\
684 	struct input_dev *input_dev = to_input_dev(dev);			\
685 	return scnprintf(buf, PAGE_SIZE, "%04x\n", input_dev->id.name);		\
686 }										\
687 static CLASS_DEVICE_ATTR(name, S_IRUGO, input_dev_show_id_##name, NULL);
688 
689 INPUT_DEV_ID_ATTR(bustype);
690 INPUT_DEV_ID_ATTR(vendor);
691 INPUT_DEV_ID_ATTR(product);
692 INPUT_DEV_ID_ATTR(version);
693 
694 static struct attribute *input_dev_id_attrs[] = {
695 	&class_device_attr_bustype.attr,
696 	&class_device_attr_vendor.attr,
697 	&class_device_attr_product.attr,
698 	&class_device_attr_version.attr,
699 	NULL
700 };
701 
702 static struct attribute_group input_dev_id_attr_group = {
703 	.name	= "id",
704 	.attrs	= input_dev_id_attrs,
705 };
706 
707 static int input_print_bitmap(char *buf, int buf_size, unsigned long *bitmap,
708 			      int max, int add_cr)
709 {
710 	int i;
711 	int len = 0;
712 
713 	for (i = NBITS(max) - 1; i > 0; i--)
714 		if (bitmap[i])
715 			break;
716 
717 	for (; i >= 0; i--)
718 		len += snprintf(buf + len, max(buf_size - len, 0),
719 				"%lx%s", bitmap[i], i > 0 ? " " : "");
720 
721 	if (add_cr)
722 		len += snprintf(buf + len, max(buf_size - len, 0), "\n");
723 
724 	return len;
725 }
726 
727 #define INPUT_DEV_CAP_ATTR(ev, bm)						\
728 static ssize_t input_dev_show_cap_##bm(struct class_device *dev, char *buf)	\
729 {										\
730 	struct input_dev *input_dev = to_input_dev(dev);			\
731 	int len = input_print_bitmap(buf, PAGE_SIZE,				\
732 				     input_dev->bm##bit, ev##_MAX, 1);		\
733 	return min_t(int, len, PAGE_SIZE);					\
734 }										\
735 static CLASS_DEVICE_ATTR(bm, S_IRUGO, input_dev_show_cap_##bm, NULL);
736 
737 INPUT_DEV_CAP_ATTR(EV, ev);
738 INPUT_DEV_CAP_ATTR(KEY, key);
739 INPUT_DEV_CAP_ATTR(REL, rel);
740 INPUT_DEV_CAP_ATTR(ABS, abs);
741 INPUT_DEV_CAP_ATTR(MSC, msc);
742 INPUT_DEV_CAP_ATTR(LED, led);
743 INPUT_DEV_CAP_ATTR(SND, snd);
744 INPUT_DEV_CAP_ATTR(FF, ff);
745 INPUT_DEV_CAP_ATTR(SW, sw);
746 
747 static struct attribute *input_dev_caps_attrs[] = {
748 	&class_device_attr_ev.attr,
749 	&class_device_attr_key.attr,
750 	&class_device_attr_rel.attr,
751 	&class_device_attr_abs.attr,
752 	&class_device_attr_msc.attr,
753 	&class_device_attr_led.attr,
754 	&class_device_attr_snd.attr,
755 	&class_device_attr_ff.attr,
756 	&class_device_attr_sw.attr,
757 	NULL
758 };
759 
760 static struct attribute_group input_dev_caps_attr_group = {
761 	.name	= "capabilities",
762 	.attrs	= input_dev_caps_attrs,
763 };
764 
765 static void input_dev_release(struct class_device *class_dev)
766 {
767 	struct input_dev *dev = to_input_dev(class_dev);
768 
769 	input_ff_destroy(dev);
770 	kfree(dev);
771 
772 	module_put(THIS_MODULE);
773 }
774 
775 /*
776  * Input uevent interface - loading event handlers based on
777  * device bitfields.
778  */
779 static int input_add_uevent_bm_var(char **envp, int num_envp, int *cur_index,
780 				   char *buffer, int buffer_size, int *cur_len,
781 				   const char *name, unsigned long *bitmap, int max)
782 {
783 	if (*cur_index >= num_envp - 1)
784 		return -ENOMEM;
785 
786 	envp[*cur_index] = buffer + *cur_len;
787 
788 	*cur_len += snprintf(buffer + *cur_len, max(buffer_size - *cur_len, 0), name);
789 	if (*cur_len >= buffer_size)
790 		return -ENOMEM;
791 
792 	*cur_len += input_print_bitmap(buffer + *cur_len,
793 					max(buffer_size - *cur_len, 0),
794 					bitmap, max, 0) + 1;
795 	if (*cur_len > buffer_size)
796 		return -ENOMEM;
797 
798 	(*cur_index)++;
799 	return 0;
800 }
801 
802 static int input_add_uevent_modalias_var(char **envp, int num_envp, int *cur_index,
803 					 char *buffer, int buffer_size, int *cur_len,
804 					 struct input_dev *dev)
805 {
806 	if (*cur_index >= num_envp - 1)
807 		return -ENOMEM;
808 
809 	envp[*cur_index] = buffer + *cur_len;
810 
811 	*cur_len += snprintf(buffer + *cur_len, max(buffer_size - *cur_len, 0),
812 			     "MODALIAS=");
813 	if (*cur_len >= buffer_size)
814 		return -ENOMEM;
815 
816 	*cur_len += input_print_modalias(buffer + *cur_len,
817 					 max(buffer_size - *cur_len, 0),
818 					 dev, 0) + 1;
819 	if (*cur_len > buffer_size)
820 		return -ENOMEM;
821 
822 	(*cur_index)++;
823 	return 0;
824 }
825 
826 #define INPUT_ADD_HOTPLUG_VAR(fmt, val...)				\
827 	do {								\
828 		int err = add_uevent_var(envp, num_envp, &i,		\
829 					buffer, buffer_size, &len,	\
830 					fmt, val);			\
831 		if (err)						\
832 			return err;					\
833 	} while (0)
834 
835 #define INPUT_ADD_HOTPLUG_BM_VAR(name, bm, max)				\
836 	do {								\
837 		int err = input_add_uevent_bm_var(envp, num_envp, &i,	\
838 					buffer, buffer_size, &len,	\
839 					name, bm, max);			\
840 		if (err)						\
841 			return err;					\
842 	} while (0)
843 
844 #define INPUT_ADD_HOTPLUG_MODALIAS_VAR(dev)				\
845 	do {								\
846 		int err = input_add_uevent_modalias_var(envp,		\
847 					num_envp, &i,			\
848 					buffer, buffer_size, &len,	\
849 					dev);				\
850 		if (err)						\
851 			return err;					\
852 	} while (0)
853 
854 static int input_dev_uevent(struct class_device *cdev, char **envp,
855 			    int num_envp, char *buffer, int buffer_size)
856 {
857 	struct input_dev *dev = to_input_dev(cdev);
858 	int i = 0;
859 	int len = 0;
860 
861 	INPUT_ADD_HOTPLUG_VAR("PRODUCT=%x/%x/%x/%x",
862 				dev->id.bustype, dev->id.vendor,
863 				dev->id.product, dev->id.version);
864 	if (dev->name)
865 		INPUT_ADD_HOTPLUG_VAR("NAME=\"%s\"", dev->name);
866 	if (dev->phys)
867 		INPUT_ADD_HOTPLUG_VAR("PHYS=\"%s\"", dev->phys);
868 	if (dev->uniq)
869 		INPUT_ADD_HOTPLUG_VAR("UNIQ=\"%s\"", dev->uniq);
870 
871 	INPUT_ADD_HOTPLUG_BM_VAR("EV=", dev->evbit, EV_MAX);
872 	if (test_bit(EV_KEY, dev->evbit))
873 		INPUT_ADD_HOTPLUG_BM_VAR("KEY=", dev->keybit, KEY_MAX);
874 	if (test_bit(EV_REL, dev->evbit))
875 		INPUT_ADD_HOTPLUG_BM_VAR("REL=", dev->relbit, REL_MAX);
876 	if (test_bit(EV_ABS, dev->evbit))
877 		INPUT_ADD_HOTPLUG_BM_VAR("ABS=", dev->absbit, ABS_MAX);
878 	if (test_bit(EV_MSC, dev->evbit))
879 		INPUT_ADD_HOTPLUG_BM_VAR("MSC=", dev->mscbit, MSC_MAX);
880 	if (test_bit(EV_LED, dev->evbit))
881 		INPUT_ADD_HOTPLUG_BM_VAR("LED=", dev->ledbit, LED_MAX);
882 	if (test_bit(EV_SND, dev->evbit))
883 		INPUT_ADD_HOTPLUG_BM_VAR("SND=", dev->sndbit, SND_MAX);
884 	if (test_bit(EV_FF, dev->evbit))
885 		INPUT_ADD_HOTPLUG_BM_VAR("FF=", dev->ffbit, FF_MAX);
886 	if (test_bit(EV_SW, dev->evbit))
887 		INPUT_ADD_HOTPLUG_BM_VAR("SW=", dev->swbit, SW_MAX);
888 
889 	INPUT_ADD_HOTPLUG_MODALIAS_VAR(dev);
890 
891 	envp[i] = NULL;
892 	return 0;
893 }
894 
895 struct class input_class = {
896 	.name			= "input",
897 	.release		= input_dev_release,
898 	.uevent			= input_dev_uevent,
899 };
900 EXPORT_SYMBOL_GPL(input_class);
901 
902 /**
903  * input_allocate_device - allocate memory for new input device
904  *
905  * Returns prepared struct input_dev or NULL.
906  *
907  * NOTE: Use input_free_device() to free devices that have not been
908  * registered; input_unregister_device() should be used for already
909  * registered devices.
910  */
911 struct input_dev *input_allocate_device(void)
912 {
913 	struct input_dev *dev;
914 
915 	dev = kzalloc(sizeof(struct input_dev), GFP_KERNEL);
916 	if (dev) {
917 		dev->cdev.class = &input_class;
918 		class_device_initialize(&dev->cdev);
919 		mutex_init(&dev->mutex);
920 		INIT_LIST_HEAD(&dev->h_list);
921 		INIT_LIST_HEAD(&dev->node);
922 
923 		__module_get(THIS_MODULE);
924 	}
925 
926 	return dev;
927 }
928 EXPORT_SYMBOL(input_allocate_device);
929 
930 /**
931  * input_free_device - free memory occupied by input_dev structure
932  * @dev: input device to free
933  *
934  * This function should only be used if input_register_device()
935  * was not called yet or if it failed. Once device was registered
936  * use input_unregister_device() and memory will be freed once last
937  * refrence to the device is dropped.
938  *
939  * Device should be allocated by input_allocate_device().
940  *
941  * NOTE: If there are references to the input device then memory
942  * will not be freed until last reference is dropped.
943  */
944 void input_free_device(struct input_dev *dev)
945 {
946 	if (dev) {
947 
948 		mutex_lock(&dev->mutex);
949 		dev->name = dev->phys = dev->uniq = NULL;
950 		mutex_unlock(&dev->mutex);
951 
952 		input_put_device(dev);
953 	}
954 }
955 EXPORT_SYMBOL(input_free_device);
956 
957 int input_register_device(struct input_dev *dev)
958 {
959 	static atomic_t input_no = ATOMIC_INIT(0);
960 	struct input_handle *handle;
961 	struct input_handler *handler;
962 	const struct input_device_id *id;
963 	const char *path;
964 	int error;
965 
966 	set_bit(EV_SYN, dev->evbit);
967 
968 	/*
969 	 * If delay and period are pre-set by the driver, then autorepeating
970 	 * is handled by the driver itself and we don't do it in input.c.
971 	 */
972 
973 	init_timer(&dev->timer);
974 	if (!dev->rep[REP_DELAY] && !dev->rep[REP_PERIOD]) {
975 		dev->timer.data = (long) dev;
976 		dev->timer.function = input_repeat_key;
977 		dev->rep[REP_DELAY] = 250;
978 		dev->rep[REP_PERIOD] = 33;
979 	}
980 
981 	list_add_tail(&dev->node, &input_dev_list);
982 
983 	snprintf(dev->cdev.class_id, sizeof(dev->cdev.class_id),
984 		 "input%ld", (unsigned long) atomic_inc_return(&input_no) - 1);
985 
986 	error = class_device_add(&dev->cdev);
987 	if (error)
988 		return error;
989 
990 	error = sysfs_create_group(&dev->cdev.kobj, &input_dev_attr_group);
991 	if (error)
992 		goto fail1;
993 
994 	error = sysfs_create_group(&dev->cdev.kobj, &input_dev_id_attr_group);
995 	if (error)
996 		goto fail2;
997 
998 	error = sysfs_create_group(&dev->cdev.kobj, &input_dev_caps_attr_group);
999 	if (error)
1000 		goto fail3;
1001 
1002 	path = kobject_get_path(&dev->cdev.kobj, GFP_KERNEL);
1003 	printk(KERN_INFO "input: %s as %s\n",
1004 		dev->name ? dev->name : "Unspecified device", path ? path : "N/A");
1005 	kfree(path);
1006 
1007 	list_for_each_entry(handler, &input_handler_list, node)
1008 		if (!handler->blacklist || !input_match_device(handler->blacklist, dev))
1009 			if ((id = input_match_device(handler->id_table, dev)))
1010 				if ((handle = handler->connect(handler, dev, id))) {
1011 					input_link_handle(handle);
1012 					if (handler->start)
1013 						handler->start(handle);
1014 				}
1015 
1016 	input_wakeup_procfs_readers();
1017 
1018 	return 0;
1019 
1020  fail3:	sysfs_remove_group(&dev->cdev.kobj, &input_dev_id_attr_group);
1021  fail2:	sysfs_remove_group(&dev->cdev.kobj, &input_dev_attr_group);
1022  fail1:	class_device_del(&dev->cdev);
1023 	return error;
1024 }
1025 EXPORT_SYMBOL(input_register_device);
1026 
1027 void input_unregister_device(struct input_dev *dev)
1028 {
1029 	struct list_head *node, *next;
1030 	int code;
1031 
1032 	for (code = 0; code <= KEY_MAX; code++)
1033 		if (test_bit(code, dev->key))
1034 			input_report_key(dev, code, 0);
1035 	input_sync(dev);
1036 
1037 	del_timer_sync(&dev->timer);
1038 
1039 	list_for_each_safe(node, next, &dev->h_list) {
1040 		struct input_handle * handle = to_handle(node);
1041 		list_del_init(&handle->d_node);
1042 		list_del_init(&handle->h_node);
1043 		handle->handler->disconnect(handle);
1044 	}
1045 
1046 	list_del_init(&dev->node);
1047 
1048 	sysfs_remove_group(&dev->cdev.kobj, &input_dev_caps_attr_group);
1049 	sysfs_remove_group(&dev->cdev.kobj, &input_dev_id_attr_group);
1050 	sysfs_remove_group(&dev->cdev.kobj, &input_dev_attr_group);
1051 
1052 	mutex_lock(&dev->mutex);
1053 	dev->name = dev->phys = dev->uniq = NULL;
1054 	mutex_unlock(&dev->mutex);
1055 
1056 	class_device_unregister(&dev->cdev);
1057 
1058 	input_wakeup_procfs_readers();
1059 }
1060 EXPORT_SYMBOL(input_unregister_device);
1061 
1062 int input_register_handler(struct input_handler *handler)
1063 {
1064 	struct input_dev *dev;
1065 	struct input_handle *handle;
1066 	const struct input_device_id *id;
1067 
1068 	INIT_LIST_HEAD(&handler->h_list);
1069 
1070 	if (handler->fops != NULL) {
1071 		if (input_table[handler->minor >> 5])
1072 			return -EBUSY;
1073 
1074 		input_table[handler->minor >> 5] = handler;
1075 	}
1076 
1077 	list_add_tail(&handler->node, &input_handler_list);
1078 
1079 	list_for_each_entry(dev, &input_dev_list, node)
1080 		if (!handler->blacklist || !input_match_device(handler->blacklist, dev))
1081 			if ((id = input_match_device(handler->id_table, dev)))
1082 				if ((handle = handler->connect(handler, dev, id))) {
1083 					input_link_handle(handle);
1084 					if (handler->start)
1085 						handler->start(handle);
1086 				}
1087 
1088 	input_wakeup_procfs_readers();
1089 	return 0;
1090 }
1091 EXPORT_SYMBOL(input_register_handler);
1092 
1093 void input_unregister_handler(struct input_handler *handler)
1094 {
1095 	struct list_head *node, *next;
1096 
1097 	list_for_each_safe(node, next, &handler->h_list) {
1098 		struct input_handle * handle = to_handle_h(node);
1099 		list_del_init(&handle->h_node);
1100 		list_del_init(&handle->d_node);
1101 		handler->disconnect(handle);
1102 	}
1103 
1104 	list_del_init(&handler->node);
1105 
1106 	if (handler->fops != NULL)
1107 		input_table[handler->minor >> 5] = NULL;
1108 
1109 	input_wakeup_procfs_readers();
1110 }
1111 EXPORT_SYMBOL(input_unregister_handler);
1112 
1113 static int input_open_file(struct inode *inode, struct file *file)
1114 {
1115 	struct input_handler *handler = input_table[iminor(inode) >> 5];
1116 	const struct file_operations *old_fops, *new_fops = NULL;
1117 	int err;
1118 
1119 	/* No load-on-demand here? */
1120 	if (!handler || !(new_fops = fops_get(handler->fops)))
1121 		return -ENODEV;
1122 
1123 	/*
1124 	 * That's _really_ odd. Usually NULL ->open means "nothing special",
1125 	 * not "no device". Oh, well...
1126 	 */
1127 	if (!new_fops->open) {
1128 		fops_put(new_fops);
1129 		return -ENODEV;
1130 	}
1131 	old_fops = file->f_op;
1132 	file->f_op = new_fops;
1133 
1134 	err = new_fops->open(inode, file);
1135 
1136 	if (err) {
1137 		fops_put(file->f_op);
1138 		file->f_op = fops_get(old_fops);
1139 	}
1140 	fops_put(old_fops);
1141 	return err;
1142 }
1143 
1144 static const struct file_operations input_fops = {
1145 	.owner = THIS_MODULE,
1146 	.open = input_open_file,
1147 };
1148 
1149 static int __init input_init(void)
1150 {
1151 	int err;
1152 
1153 	err = class_register(&input_class);
1154 	if (err) {
1155 		printk(KERN_ERR "input: unable to register input_dev class\n");
1156 		return err;
1157 	}
1158 
1159 	err = input_proc_init();
1160 	if (err)
1161 		goto fail1;
1162 
1163 	err = register_chrdev(INPUT_MAJOR, "input", &input_fops);
1164 	if (err) {
1165 		printk(KERN_ERR "input: unable to register char major %d", INPUT_MAJOR);
1166 		goto fail2;
1167 	}
1168 
1169 	return 0;
1170 
1171  fail2:	input_proc_exit();
1172  fail1:	class_unregister(&input_class);
1173 	return err;
1174 }
1175 
1176 static void __exit input_exit(void)
1177 {
1178 	input_proc_exit();
1179 	unregister_chrdev(INPUT_MAJOR, "input");
1180 	class_unregister(&input_class);
1181 }
1182 
1183 subsys_initcall(input_init);
1184 module_exit(input_exit);
1185