xref: /openbmc/linux/drivers/input/input.c (revision 1da177e4) 
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/sched.h>
15 #include <linux/smp_lock.h>
16 #include <linux/input.h>
17 #include <linux/module.h>
18 #include <linux/random.h>
19 #include <linux/major.h>
20 #include <linux/proc_fs.h>
21 #include <linux/kobject_uevent.h>
22 #include <linux/interrupt.h>
23 #include <linux/poll.h>
24 #include <linux/device.h>
25 #include <linux/devfs_fs_kernel.h>
26 
27 MODULE_AUTHOR("Vojtech Pavlik <vojtech@suse.cz>");
28 MODULE_DESCRIPTION("Input core");
29 MODULE_LICENSE("GPL");
30 
31 EXPORT_SYMBOL(input_register_device);
32 EXPORT_SYMBOL(input_unregister_device);
33 EXPORT_SYMBOL(input_register_handler);
34 EXPORT_SYMBOL(input_unregister_handler);
35 EXPORT_SYMBOL(input_grab_device);
36 EXPORT_SYMBOL(input_release_device);
37 EXPORT_SYMBOL(input_open_device);
38 EXPORT_SYMBOL(input_close_device);
39 EXPORT_SYMBOL(input_accept_process);
40 EXPORT_SYMBOL(input_flush_device);
41 EXPORT_SYMBOL(input_event);
42 EXPORT_SYMBOL(input_class);
43 
44 #define INPUT_DEVICES	256
45 
46 static LIST_HEAD(input_dev_list);
47 static LIST_HEAD(input_handler_list);
48 
49 static struct input_handler *input_table[8];
50 
51 #ifdef CONFIG_PROC_FS
52 static struct proc_dir_entry *proc_bus_input_dir;
53 static DECLARE_WAIT_QUEUE_HEAD(input_devices_poll_wait);
54 static int input_devices_state;
55 #endif
56 
57 void input_event(struct input_dev *dev, unsigned int type, unsigned int code, int value)
58 {
59 	struct input_handle *handle;
60 
61 	if (type > EV_MAX || !test_bit(type, dev->evbit))
62 		return;
63 
64 	add_input_randomness(type, code, value);
65 
66 	switch (type) {
67 
68 		case EV_SYN:
69 			switch (code) {
70 				case SYN_CONFIG:
71 					if (dev->event) dev->event(dev, type, code, value);
72 					break;
73 
74 				case SYN_REPORT:
75 					if (dev->sync) return;
76 					dev->sync = 1;
77 					break;
78 			}
79 			break;
80 
81 		case EV_KEY:
82 
83 			if (code > KEY_MAX || !test_bit(code, dev->keybit) || !!test_bit(code, dev->key) == value)
84 				return;
85 
86 			if (value == 2)
87 				break;
88 
89 			change_bit(code, dev->key);
90 
91 			if (test_bit(EV_REP, dev->evbit) && dev->rep[REP_PERIOD] && dev->rep[REP_DELAY] && dev->timer.data && value) {
92 				dev->repeat_key = code;
93 				mod_timer(&dev->timer, jiffies + msecs_to_jiffies(dev->rep[REP_DELAY]));
94 			}
95 
96 			break;
97 
98 		case EV_ABS:
99 
100 			if (code > ABS_MAX || !test_bit(code, dev->absbit))
101 				return;
102 
103 			if (dev->absfuzz[code]) {
104 				if ((value > dev->abs[code] - (dev->absfuzz[code] >> 1)) &&
105 				    (value < dev->abs[code] + (dev->absfuzz[code] >> 1)))
106 					return;
107 
108 				if ((value > dev->abs[code] - dev->absfuzz[code]) &&
109 				    (value < dev->abs[code] + dev->absfuzz[code]))
110 					value = (dev->abs[code] * 3 + value) >> 2;
111 
112 				if ((value > dev->abs[code] - (dev->absfuzz[code] << 1)) &&
113 				    (value < dev->abs[code] + (dev->absfuzz[code] << 1)))
114 					value = (dev->abs[code] + value) >> 1;
115 			}
116 
117 			if (dev->abs[code] == value)
118 				return;
119 
120 			dev->abs[code] = value;
121 			break;
122 
123 		case EV_REL:
124 
125 			if (code > REL_MAX || !test_bit(code, dev->relbit) || (value == 0))
126 				return;
127 
128 			break;
129 
130 		case EV_MSC:
131 
132 			if (code > MSC_MAX || !test_bit(code, dev->mscbit))
133 				return;
134 
135 			if (dev->event) dev->event(dev, type, code, value);
136 
137 			break;
138 
139 		case EV_LED:
140 
141 			if (code > LED_MAX || !test_bit(code, dev->ledbit) || !!test_bit(code, dev->led) == value)
142 				return;
143 
144 			change_bit(code, dev->led);
145 			if (dev->event) dev->event(dev, type, code, value);
146 
147 			break;
148 
149 		case EV_SND:
150 
151 			if (code > SND_MAX || !test_bit(code, dev->sndbit))
152 				return;
153 
154 			if (dev->event) dev->event(dev, type, code, value);
155 
156 			break;
157 
158 		case EV_REP:
159 
160 			if (code > REP_MAX || value < 0 || dev->rep[code] == value) return;
161 
162 			dev->rep[code] = value;
163 			if (dev->event) dev->event(dev, type, code, value);
164 
165 			break;
166 
167 		case EV_FF:
168 			if (dev->event) dev->event(dev, type, code, value);
169 			break;
170 	}
171 
172 	if (type != EV_SYN)
173 		dev->sync = 0;
174 
175 	if (dev->grab)
176 		dev->grab->handler->event(dev->grab, type, code, value);
177 	else
178 		list_for_each_entry(handle, &dev->h_list, d_node)
179 			if (handle->open)
180 				handle->handler->event(handle, type, code, value);
181 }
182 
183 static void input_repeat_key(unsigned long data)
184 {
185 	struct input_dev *dev = (void *) data;
186 
187 	if (!test_bit(dev->repeat_key, dev->key))
188 		return;
189 
190 	input_event(dev, EV_KEY, dev->repeat_key, 2);
191 	input_sync(dev);
192 
193 	if (dev->rep[REP_PERIOD])
194 		mod_timer(&dev->timer, jiffies + msecs_to_jiffies(dev->rep[REP_PERIOD]));
195 }
196 
197 int input_accept_process(struct input_handle *handle, struct file *file)
198 {
199 	if (handle->dev->accept)
200 		return handle->dev->accept(handle->dev, file);
201 
202 	return 0;
203 }
204 
205 int input_grab_device(struct input_handle *handle)
206 {
207 	if (handle->dev->grab)
208 		return -EBUSY;
209 
210 	handle->dev->grab = handle;
211 	return 0;
212 }
213 
214 void input_release_device(struct input_handle *handle)
215 {
216 	if (handle->dev->grab == handle)
217 		handle->dev->grab = NULL;
218 }
219 
220 int input_open_device(struct input_handle *handle)
221 {
222 	handle->open++;
223 	if (handle->dev->open)
224 		return handle->dev->open(handle->dev);
225 	return 0;
226 }
227 
228 int input_flush_device(struct input_handle* handle, struct file* file)
229 {
230 	if (handle->dev->flush)
231 		return handle->dev->flush(handle->dev, file);
232 
233 	return 0;
234 }
235 
236 void input_close_device(struct input_handle *handle)
237 {
238 	input_release_device(handle);
239 	if (handle->dev->close)
240 		handle->dev->close(handle->dev);
241 	handle->open--;
242 }
243 
244 static void input_link_handle(struct input_handle *handle)
245 {
246 	list_add_tail(&handle->d_node, &handle->dev->h_list);
247 	list_add_tail(&handle->h_node, &handle->handler->h_list);
248 }
249 
250 #define MATCH_BIT(bit, max) \
251 		for (i = 0; i < NBITS(max); i++) \
252 			if ((id->bit[i] & dev->bit[i]) != id->bit[i]) \
253 				break; \
254 		if (i != NBITS(max)) \
255 			continue;
256 
257 static struct input_device_id *input_match_device(struct input_device_id *id, struct input_dev *dev)
258 {
259 	int i;
260 
261 	for (; id->flags || id->driver_info; id++) {
262 
263 		if (id->flags & INPUT_DEVICE_ID_MATCH_BUS)
264 			if (id->id.bustype != dev->id.bustype)
265 				continue;
266 
267 		if (id->flags & INPUT_DEVICE_ID_MATCH_VENDOR)
268 			if (id->id.vendor != dev->id.vendor)
269 				continue;
270 
271 		if (id->flags & INPUT_DEVICE_ID_MATCH_PRODUCT)
272 			if (id->id.product != dev->id.product)
273 				continue;
274 
275 		if (id->flags & INPUT_DEVICE_ID_MATCH_VERSION)
276 			if (id->id.version != dev->id.version)
277 				continue;
278 
279 		MATCH_BIT(evbit,  EV_MAX);
280 		MATCH_BIT(keybit, KEY_MAX);
281 		MATCH_BIT(relbit, REL_MAX);
282 		MATCH_BIT(absbit, ABS_MAX);
283 		MATCH_BIT(mscbit, MSC_MAX);
284 		MATCH_BIT(ledbit, LED_MAX);
285 		MATCH_BIT(sndbit, SND_MAX);
286 		MATCH_BIT(ffbit,  FF_MAX);
287 
288 		return id;
289 	}
290 
291 	return NULL;
292 }
293 
294 /*
295  * Input hotplugging interface - loading event handlers based on
296  * device bitfields.
297  */
298 
299 #ifdef CONFIG_HOTPLUG
300 
301 /*
302  * Input hotplugging invokes what /proc/sys/kernel/hotplug says
303  * (normally /sbin/hotplug) when input devices get added or removed.
304  *
305  * This invokes a user mode policy agent, typically helping to load driver
306  * or other modules, configure the device, and more.  Drivers can provide
307  * a MODULE_DEVICE_TABLE to help with module loading subtasks.
308  *
309  */
310 
311 #define SPRINTF_BIT_A(bit, name, max) \
312 	do { \
313 		envp[i++] = scratch; \
314 		scratch += sprintf(scratch, name); \
315 		for (j = NBITS(max) - 1; j >= 0; j--) \
316 			if (dev->bit[j]) break; \
317 		for (; j >= 0; j--) \
318 			scratch += sprintf(scratch, "%lx ", dev->bit[j]); \
319 		scratch++; \
320 	} while (0)
321 
322 #define SPRINTF_BIT_A2(bit, name, max, ev) \
323 	do { \
324 		if (test_bit(ev, dev->evbit)) \
325 			SPRINTF_BIT_A(bit, name, max); \
326 	} while (0)
327 
328 static void input_call_hotplug(char *verb, struct input_dev *dev)
329 {
330 	char *argv[3], **envp, *buf, *scratch;
331 	int i = 0, j, value;
332 
333 	if (!hotplug_path[0]) {
334 		printk(KERN_ERR "input.c: calling hotplug without a hotplug agent defined\n");
335 		return;
336 	}
337 	if (in_interrupt()) {
338 		printk(KERN_ERR "input.c: calling hotplug from interrupt\n");
339 		return;
340 	}
341 	if (!current->fs->root) {
342 		printk(KERN_WARNING "input.c: calling hotplug without valid filesystem\n");
343 		return;
344 	}
345 	if (!(envp = (char **) kmalloc(20 * sizeof(char *), GFP_KERNEL))) {
346 		printk(KERN_ERR "input.c: not enough memory allocating hotplug environment\n");
347 		return;
348 	}
349 	if (!(buf = kmalloc(1024, GFP_KERNEL))) {
350 		kfree (envp);
351 		printk(KERN_ERR "input.c: not enough memory allocating hotplug environment\n");
352 		return;
353 	}
354 
355 	argv[0] = hotplug_path;
356 	argv[1] = "input";
357 	argv[2] = NULL;
358 
359 	envp[i++] = "HOME=/";
360 	envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
361 
362 	scratch = buf;
363 
364 	envp[i++] = scratch;
365 	scratch += sprintf(scratch, "ACTION=%s", verb) + 1;
366 
367 	envp[i++] = scratch;
368 	scratch += sprintf(scratch, "PRODUCT=%x/%x/%x/%x",
369 		dev->id.bustype, dev->id.vendor, dev->id.product, dev->id.version) + 1;
370 
371 	if (dev->name) {
372 		envp[i++] = scratch;
373 		scratch += sprintf(scratch, "NAME=%s", dev->name) + 1;
374 	}
375 
376 	if (dev->phys) {
377 		envp[i++] = scratch;
378 		scratch += sprintf(scratch, "PHYS=%s", dev->phys) + 1;
379 	}
380 
381 	SPRINTF_BIT_A(evbit, "EV=", EV_MAX);
382 	SPRINTF_BIT_A2(keybit, "KEY=", KEY_MAX, EV_KEY);
383 	SPRINTF_BIT_A2(relbit, "REL=", REL_MAX, EV_REL);
384 	SPRINTF_BIT_A2(absbit, "ABS=", ABS_MAX, EV_ABS);
385 	SPRINTF_BIT_A2(mscbit, "MSC=", MSC_MAX, EV_MSC);
386 	SPRINTF_BIT_A2(ledbit, "LED=", LED_MAX, EV_LED);
387 	SPRINTF_BIT_A2(sndbit, "SND=", SND_MAX, EV_SND);
388 	SPRINTF_BIT_A2(ffbit,  "FF=",  FF_MAX, EV_FF);
389 
390 	envp[i++] = NULL;
391 
392 #ifdef INPUT_DEBUG
393 	printk(KERN_DEBUG "input.c: calling %s %s [%s %s %s %s %s]\n",
394 		argv[0], argv[1], envp[0], envp[1], envp[2], envp[3], envp[4]);
395 #endif
396 
397 	value = call_usermodehelper(argv [0], argv, envp, 0);
398 
399 	kfree(buf);
400 	kfree(envp);
401 
402 #ifdef INPUT_DEBUG
403 	if (value != 0)
404 		printk(KERN_DEBUG "input.c: hotplug returned %d\n", value);
405 #endif
406 }
407 
408 #endif
409 
410 void input_register_device(struct input_dev *dev)
411 {
412 	struct input_handle *handle;
413 	struct input_handler *handler;
414 	struct input_device_id *id;
415 
416 	set_bit(EV_SYN, dev->evbit);
417 
418 	/*
419 	 * If delay and period are pre-set by the driver, then autorepeating
420 	 * is handled by the driver itself and we don't do it in input.c.
421 	 */
422 
423 	init_timer(&dev->timer);
424 	if (!dev->rep[REP_DELAY] && !dev->rep[REP_PERIOD]) {
425 		dev->timer.data = (long) dev;
426 		dev->timer.function = input_repeat_key;
427 		dev->rep[REP_DELAY] = 250;
428 		dev->rep[REP_PERIOD] = 33;
429 	}
430 
431 	INIT_LIST_HEAD(&dev->h_list);
432 	list_add_tail(&dev->node, &input_dev_list);
433 
434 	list_for_each_entry(handler, &input_handler_list, node)
435 		if (!handler->blacklist || !input_match_device(handler->blacklist, dev))
436 			if ((id = input_match_device(handler->id_table, dev)))
437 				if ((handle = handler->connect(handler, dev, id)))
438 					input_link_handle(handle);
439 
440 #ifdef CONFIG_HOTPLUG
441 	input_call_hotplug("add", dev);
442 #endif
443 
444 #ifdef CONFIG_PROC_FS
445 	input_devices_state++;
446 	wake_up(&input_devices_poll_wait);
447 #endif
448 }
449 
450 void input_unregister_device(struct input_dev *dev)
451 {
452 	struct list_head * node, * next;
453 
454 	if (!dev) return;
455 
456 	del_timer_sync(&dev->timer);
457 
458 	list_for_each_safe(node, next, &dev->h_list) {
459 		struct input_handle * handle = to_handle(node);
460 		list_del_init(&handle->d_node);
461 		list_del_init(&handle->h_node);
462 		handle->handler->disconnect(handle);
463 	}
464 
465 #ifdef CONFIG_HOTPLUG
466 	input_call_hotplug("remove", dev);
467 #endif
468 
469 	list_del_init(&dev->node);
470 
471 #ifdef CONFIG_PROC_FS
472 	input_devices_state++;
473 	wake_up(&input_devices_poll_wait);
474 #endif
475 }
476 
477 void input_register_handler(struct input_handler *handler)
478 {
479 	struct input_dev *dev;
480 	struct input_handle *handle;
481 	struct input_device_id *id;
482 
483 	if (!handler) return;
484 
485 	INIT_LIST_HEAD(&handler->h_list);
486 
487 	if (handler->fops != NULL)
488 		input_table[handler->minor >> 5] = handler;
489 
490 	list_add_tail(&handler->node, &input_handler_list);
491 
492 	list_for_each_entry(dev, &input_dev_list, node)
493 		if (!handler->blacklist || !input_match_device(handler->blacklist, dev))
494 			if ((id = input_match_device(handler->id_table, dev)))
495 				if ((handle = handler->connect(handler, dev, id)))
496 					input_link_handle(handle);
497 
498 #ifdef CONFIG_PROC_FS
499 	input_devices_state++;
500 	wake_up(&input_devices_poll_wait);
501 #endif
502 }
503 
504 void input_unregister_handler(struct input_handler *handler)
505 {
506 	struct list_head * node, * next;
507 
508 	list_for_each_safe(node, next, &handler->h_list) {
509 		struct input_handle * handle = to_handle_h(node);
510 		list_del_init(&handle->h_node);
511 		list_del_init(&handle->d_node);
512 		handler->disconnect(handle);
513 	}
514 
515 	list_del_init(&handler->node);
516 
517 	if (handler->fops != NULL)
518 		input_table[handler->minor >> 5] = NULL;
519 
520 #ifdef CONFIG_PROC_FS
521 	input_devices_state++;
522 	wake_up(&input_devices_poll_wait);
523 #endif
524 }
525 
526 static int input_open_file(struct inode *inode, struct file *file)
527 {
528 	struct input_handler *handler = input_table[iminor(inode) >> 5];
529 	struct file_operations *old_fops, *new_fops = NULL;
530 	int err;
531 
532 	/* No load-on-demand here? */
533 	if (!handler || !(new_fops = fops_get(handler->fops)))
534 		return -ENODEV;
535 
536 	/*
537 	 * That's _really_ odd. Usually NULL ->open means "nothing special",
538 	 * not "no device". Oh, well...
539 	 */
540 	if (!new_fops->open) {
541 		fops_put(new_fops);
542 		return -ENODEV;
543 	}
544 	old_fops = file->f_op;
545 	file->f_op = new_fops;
546 
547 	err = new_fops->open(inode, file);
548 
549 	if (err) {
550 		fops_put(file->f_op);
551 		file->f_op = fops_get(old_fops);
552 	}
553 	fops_put(old_fops);
554 	return err;
555 }
556 
557 static struct file_operations input_fops = {
558 	.owner = THIS_MODULE,
559 	.open = input_open_file,
560 };
561 
562 #ifdef CONFIG_PROC_FS
563 
564 #define SPRINTF_BIT_B(bit, name, max) \
565 	do { \
566 		len += sprintf(buf + len, "B: %s", name); \
567 		for (i = NBITS(max) - 1; i >= 0; i--) \
568 			if (dev->bit[i]) break; \
569 		for (; i >= 0; i--) \
570 			len += sprintf(buf + len, "%lx ", dev->bit[i]); \
571 		len += sprintf(buf + len, "\n"); \
572 	} while (0)
573 
574 #define SPRINTF_BIT_B2(bit, name, max, ev) \
575 	do { \
576 		if (test_bit(ev, dev->evbit)) \
577 			SPRINTF_BIT_B(bit, name, max); \
578 	} while (0)
579 
580 
581 static unsigned int input_devices_poll(struct file *file, poll_table *wait)
582 {
583 	int state = input_devices_state;
584 	poll_wait(file, &input_devices_poll_wait, wait);
585 	if (state != input_devices_state)
586 		return POLLIN | POLLRDNORM;
587 	return 0;
588 }
589 
590 static int input_devices_read(char *buf, char **start, off_t pos, int count, int *eof, void *data)
591 {
592 	struct input_dev *dev;
593 	struct input_handle *handle;
594 
595 	off_t at = 0;
596 	int i, len, cnt = 0;
597 
598 	list_for_each_entry(dev, &input_dev_list, node) {
599 
600 		len = sprintf(buf, "I: Bus=%04x Vendor=%04x Product=%04x Version=%04x\n",
601 			dev->id.bustype, dev->id.vendor, dev->id.product, dev->id.version);
602 
603 		len += sprintf(buf + len, "N: Name=\"%s\"\n", dev->name ? dev->name : "");
604 		len += sprintf(buf + len, "P: Phys=%s\n", dev->phys ? dev->phys : "");
605 		len += sprintf(buf + len, "H: Handlers=");
606 
607 		list_for_each_entry(handle, &dev->h_list, d_node)
608 			len += sprintf(buf + len, "%s ", handle->name);
609 
610 		len += sprintf(buf + len, "\n");
611 
612 		SPRINTF_BIT_B(evbit, "EV=", EV_MAX);
613 		SPRINTF_BIT_B2(keybit, "KEY=", KEY_MAX, EV_KEY);
614 		SPRINTF_BIT_B2(relbit, "REL=", REL_MAX, EV_REL);
615 		SPRINTF_BIT_B2(absbit, "ABS=", ABS_MAX, EV_ABS);
616 		SPRINTF_BIT_B2(mscbit, "MSC=", MSC_MAX, EV_MSC);
617 		SPRINTF_BIT_B2(ledbit, "LED=", LED_MAX, EV_LED);
618 		SPRINTF_BIT_B2(sndbit, "SND=", SND_MAX, EV_SND);
619 		SPRINTF_BIT_B2(ffbit,  "FF=",  FF_MAX, EV_FF);
620 
621 		len += sprintf(buf + len, "\n");
622 
623 		at += len;
624 
625 		if (at >= pos) {
626 			if (!*start) {
627 				*start = buf + (pos - (at - len));
628 				cnt = at - pos;
629 			} else  cnt += len;
630 			buf += len;
631 			if (cnt >= count)
632 				break;
633 		}
634 	}
635 
636 	if (&dev->node == &input_dev_list)
637 		*eof = 1;
638 
639 	return (count > cnt) ? cnt : count;
640 }
641 
642 static int input_handlers_read(char *buf, char **start, off_t pos, int count, int *eof, void *data)
643 {
644 	struct input_handler *handler;
645 
646 	off_t at = 0;
647 	int len = 0, cnt = 0;
648 	int i = 0;
649 
650 	list_for_each_entry(handler, &input_handler_list, node) {
651 
652 		if (handler->fops)
653 			len = sprintf(buf, "N: Number=%d Name=%s Minor=%d\n",
654 				i++, handler->name, handler->minor);
655 		else
656 			len = sprintf(buf, "N: Number=%d Name=%s\n",
657 				i++, handler->name);
658 
659 		at += len;
660 
661 		if (at >= pos) {
662 			if (!*start) {
663 				*start = buf + (pos - (at - len));
664 				cnt = at - pos;
665 			} else  cnt += len;
666 			buf += len;
667 			if (cnt >= count)
668 				break;
669 		}
670 	}
671 	if (&handler->node == &input_handler_list)
672 		*eof = 1;
673 
674 	return (count > cnt) ? cnt : count;
675 }
676 
677 static int __init input_proc_init(void)
678 {
679 	struct proc_dir_entry *entry;
680 
681 	proc_bus_input_dir = proc_mkdir("input", proc_bus);
682 	if (proc_bus_input_dir == NULL)
683 		return -ENOMEM;
684 	proc_bus_input_dir->owner = THIS_MODULE;
685 	entry = create_proc_read_entry("devices", 0, proc_bus_input_dir, input_devices_read, NULL);
686 	if (entry == NULL) {
687 		remove_proc_entry("input", proc_bus);
688 		return -ENOMEM;
689 	}
690 	entry->owner = THIS_MODULE;
691 	entry->proc_fops->poll = input_devices_poll;
692 	entry = create_proc_read_entry("handlers", 0, proc_bus_input_dir, input_handlers_read, NULL);
693 	if (entry == NULL) {
694 		remove_proc_entry("devices", proc_bus_input_dir);
695 		remove_proc_entry("input", proc_bus);
696 		return -ENOMEM;
697 	}
698 	entry->owner = THIS_MODULE;
699 	return 0;
700 }
701 #else /* !CONFIG_PROC_FS */
702 static inline int input_proc_init(void) { return 0; }
703 #endif
704 
705 struct class_simple *input_class;
706 
707 static int __init input_init(void)
708 {
709 	int retval = -ENOMEM;
710 
711 	input_class = class_simple_create(THIS_MODULE, "input");
712 	if (IS_ERR(input_class))
713 		return PTR_ERR(input_class);
714 	input_proc_init();
715 	retval = register_chrdev(INPUT_MAJOR, "input", &input_fops);
716 	if (retval) {
717 		printk(KERN_ERR "input: unable to register char major %d", INPUT_MAJOR);
718 		remove_proc_entry("devices", proc_bus_input_dir);
719 		remove_proc_entry("handlers", proc_bus_input_dir);
720 		remove_proc_entry("input", proc_bus);
721 		class_simple_destroy(input_class);
722 		return retval;
723 	}
724 
725 	retval = devfs_mk_dir("input");
726 	if (retval) {
727 		remove_proc_entry("devices", proc_bus_input_dir);
728 		remove_proc_entry("handlers", proc_bus_input_dir);
729 		remove_proc_entry("input", proc_bus);
730 		unregister_chrdev(INPUT_MAJOR, "input");
731 		class_simple_destroy(input_class);
732 	}
733 	return retval;
734 }
735 
736 static void __exit input_exit(void)
737 {
738 	remove_proc_entry("devices", proc_bus_input_dir);
739 	remove_proc_entry("handlers", proc_bus_input_dir);
740 	remove_proc_entry("input", proc_bus);
741 
742 	devfs_remove("input");
743 	unregister_chrdev(INPUT_MAJOR, "input");
744 	class_simple_destroy(input_class);
745 }
746 
747 subsys_initcall(input_init);
748 module_exit(input_exit);
749