xref: /linux/drivers/input/evdev.c (revision 858259cf7d1c443c836a2022b78cb281f0a9b95e)
1 /*
2  * Event char devices, giving access to raw input device events.
3  *
4  * Copyright (c) 1999-2002 Vojtech Pavlik
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms of the GNU General Public License version 2 as published by
8  * the Free Software Foundation.
9  */
10 
11 #define EVDEV_MINOR_BASE	64
12 #define EVDEV_MINORS		32
13 #define EVDEV_BUFFER_SIZE	64
14 
15 #include <linux/poll.h>
16 #include <linux/slab.h>
17 #include <linux/module.h>
18 #include <linux/init.h>
19 #include <linux/input.h>
20 #include <linux/major.h>
21 #include <linux/smp_lock.h>
22 #include <linux/device.h>
23 #include <linux/compat.h>
24 
25 struct evdev {
26 	int exist;
27 	int open;
28 	int minor;
29 	char name[16];
30 	struct input_handle handle;
31 	wait_queue_head_t wait;
32 	struct evdev_list *grab;
33 	struct list_head list;
34 };
35 
36 struct evdev_list {
37 	struct input_event buffer[EVDEV_BUFFER_SIZE];
38 	int head;
39 	int tail;
40 	struct fasync_struct *fasync;
41 	struct evdev *evdev;
42 	struct list_head node;
43 };
44 
45 static struct evdev *evdev_table[EVDEV_MINORS];
46 
47 static void evdev_event(struct input_handle *handle, unsigned int type, unsigned int code, int value)
48 {
49 	struct evdev *evdev = handle->private;
50 	struct evdev_list *list;
51 
52 	if (evdev->grab) {
53 		list = evdev->grab;
54 
55 		do_gettimeofday(&list->buffer[list->head].time);
56 		list->buffer[list->head].type = type;
57 		list->buffer[list->head].code = code;
58 		list->buffer[list->head].value = value;
59 		list->head = (list->head + 1) & (EVDEV_BUFFER_SIZE - 1);
60 
61 		kill_fasync(&list->fasync, SIGIO, POLL_IN);
62 	} else
63 		list_for_each_entry(list, &evdev->list, node) {
64 
65 			do_gettimeofday(&list->buffer[list->head].time);
66 			list->buffer[list->head].type = type;
67 			list->buffer[list->head].code = code;
68 			list->buffer[list->head].value = value;
69 			list->head = (list->head + 1) & (EVDEV_BUFFER_SIZE - 1);
70 
71 			kill_fasync(&list->fasync, SIGIO, POLL_IN);
72 		}
73 
74 	wake_up_interruptible(&evdev->wait);
75 }
76 
77 static int evdev_fasync(int fd, struct file *file, int on)
78 {
79 	int retval;
80 	struct evdev_list *list = file->private_data;
81 	retval = fasync_helper(fd, file, on, &list->fasync);
82 	return retval < 0 ? retval : 0;
83 }
84 
85 static int evdev_flush(struct file * file)
86 {
87 	struct evdev_list *list = file->private_data;
88 	if (!list->evdev->exist) return -ENODEV;
89 	return input_flush_device(&list->evdev->handle, file);
90 }
91 
92 static void evdev_free(struct evdev *evdev)
93 {
94 	evdev_table[evdev->minor] = NULL;
95 	kfree(evdev);
96 }
97 
98 static int evdev_release(struct inode * inode, struct file * file)
99 {
100 	struct evdev_list *list = file->private_data;
101 
102 	if (list->evdev->grab == list) {
103 		input_release_device(&list->evdev->handle);
104 		list->evdev->grab = NULL;
105 	}
106 
107 	evdev_fasync(-1, file, 0);
108 	list_del(&list->node);
109 
110 	if (!--list->evdev->open) {
111 		if (list->evdev->exist)
112 			input_close_device(&list->evdev->handle);
113 		else
114 			evdev_free(list->evdev);
115 	}
116 
117 	kfree(list);
118 	return 0;
119 }
120 
121 static int evdev_open(struct inode * inode, struct file * file)
122 {
123 	struct evdev_list *list;
124 	int i = iminor(inode) - EVDEV_MINOR_BASE;
125 	int accept_err;
126 
127 	if (i >= EVDEV_MINORS || !evdev_table[i] || !evdev_table[i]->exist)
128 		return -ENODEV;
129 
130 	if ((accept_err = input_accept_process(&(evdev_table[i]->handle), file)))
131 		return accept_err;
132 
133 	if (!(list = kmalloc(sizeof(struct evdev_list), GFP_KERNEL)))
134 		return -ENOMEM;
135 	memset(list, 0, sizeof(struct evdev_list));
136 
137 	list->evdev = evdev_table[i];
138 	list_add_tail(&list->node, &evdev_table[i]->list);
139 	file->private_data = list;
140 
141 	if (!list->evdev->open++)
142 		if (list->evdev->exist)
143 			input_open_device(&list->evdev->handle);
144 
145 	return 0;
146 }
147 
148 #ifdef CONFIG_COMPAT
149 struct input_event_compat {
150 	struct compat_timeval time;
151 	__u16 type;
152 	__u16 code;
153 	__s32 value;
154 };
155 
156 #ifdef CONFIG_X86_64
157 #  define COMPAT_TEST test_thread_flag(TIF_IA32)
158 #elif defined(CONFIG_IA64)
159 #  define COMPAT_TEST IS_IA32_PROCESS(ia64_task_regs(current))
160 #elif defined(CONFIG_ARCH_S390)
161 #  define COMPAT_TEST test_thread_flag(TIF_31BIT)
162 #elif defined(CONFIG_MIPS)
163 #  define COMPAT_TEST (current->thread.mflags & MF_32BIT_ADDR)
164 #else
165 #  define COMPAT_TEST test_thread_flag(TIF_32BIT)
166 #endif
167 
168 static ssize_t evdev_write_compat(struct file * file, const char __user * buffer, size_t count, loff_t *ppos)
169 {
170 	struct evdev_list *list = file->private_data;
171 	struct input_event_compat event;
172 	int retval = 0;
173 
174 	while (retval < count) {
175 		if (copy_from_user(&event, buffer + retval, sizeof(struct input_event_compat)))
176 			return -EFAULT;
177 		input_event(list->evdev->handle.dev, event.type, event.code, event.value);
178 		retval += sizeof(struct input_event_compat);
179 	}
180 
181 	return retval;
182 }
183 #endif
184 
185 static ssize_t evdev_write(struct file * file, const char __user * buffer, size_t count, loff_t *ppos)
186 {
187 	struct evdev_list *list = file->private_data;
188 	struct input_event event;
189 	int retval = 0;
190 
191 	if (!list->evdev->exist) return -ENODEV;
192 
193 #ifdef CONFIG_COMPAT
194 	if (COMPAT_TEST)
195 		return evdev_write_compat(file, buffer, count, ppos);
196 #endif
197 
198 	while (retval < count) {
199 
200 		if (copy_from_user(&event, buffer + retval, sizeof(struct input_event)))
201 			return -EFAULT;
202 		input_event(list->evdev->handle.dev, event.type, event.code, event.value);
203 		retval += sizeof(struct input_event);
204 	}
205 
206 	return retval;
207 }
208 
209 #ifdef CONFIG_COMPAT
210 static ssize_t evdev_read_compat(struct file * file, char __user * buffer, size_t count, loff_t *ppos)
211 {
212 	struct evdev_list *list = file->private_data;
213 	int retval;
214 
215 	if (count < sizeof(struct input_event_compat))
216 		return -EINVAL;
217 
218 	if (list->head == list->tail && list->evdev->exist && (file->f_flags & O_NONBLOCK))
219 		return -EAGAIN;
220 
221 	retval = wait_event_interruptible(list->evdev->wait,
222 		list->head != list->tail || (!list->evdev->exist));
223 
224 	if (retval)
225 		return retval;
226 
227 	if (!list->evdev->exist)
228 		return -ENODEV;
229 
230 	while (list->head != list->tail && retval + sizeof(struct input_event_compat) <= count) {
231 		struct input_event *event = (struct input_event *) list->buffer + list->tail;
232 		struct input_event_compat event_compat;
233 		event_compat.time.tv_sec = event->time.tv_sec;
234 		event_compat.time.tv_usec = event->time.tv_usec;
235 		event_compat.type = event->type;
236 		event_compat.code = event->code;
237 		event_compat.value = event->value;
238 
239 		if (copy_to_user(buffer + retval, &event_compat,
240 			sizeof(struct input_event_compat))) return -EFAULT;
241 		list->tail = (list->tail + 1) & (EVDEV_BUFFER_SIZE - 1);
242 		retval += sizeof(struct input_event_compat);
243 	}
244 
245 	return retval;
246 }
247 #endif
248 
249 static ssize_t evdev_read(struct file * file, char __user * buffer, size_t count, loff_t *ppos)
250 {
251 	struct evdev_list *list = file->private_data;
252 	int retval;
253 
254 #ifdef CONFIG_COMPAT
255 	if (COMPAT_TEST)
256 		return evdev_read_compat(file, buffer, count, ppos);
257 #endif
258 
259 	if (count < sizeof(struct input_event))
260 		return -EINVAL;
261 
262 	if (list->head == list->tail && list->evdev->exist && (file->f_flags & O_NONBLOCK))
263 		return -EAGAIN;
264 
265 	retval = wait_event_interruptible(list->evdev->wait,
266 		list->head != list->tail || (!list->evdev->exist));
267 
268 	if (retval)
269 		return retval;
270 
271 	if (!list->evdev->exist)
272 		return -ENODEV;
273 
274 	while (list->head != list->tail && retval + sizeof(struct input_event) <= count) {
275 		if (copy_to_user(buffer + retval, list->buffer + list->tail,
276 			sizeof(struct input_event))) return -EFAULT;
277 		list->tail = (list->tail + 1) & (EVDEV_BUFFER_SIZE - 1);
278 		retval += sizeof(struct input_event);
279 	}
280 
281 	return retval;
282 }
283 
284 /* No kernel lock - fine */
285 static unsigned int evdev_poll(struct file *file, poll_table *wait)
286 {
287 	struct evdev_list *list = file->private_data;
288 	poll_wait(file, &list->evdev->wait, wait);
289 	return ((list->head == list->tail) ? 0 : (POLLIN | POLLRDNORM)) |
290 		(list->evdev->exist ? 0 : (POLLHUP | POLLERR));
291 }
292 
293 static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
294 {
295 	struct evdev_list *list = file->private_data;
296 	struct evdev *evdev = list->evdev;
297 	struct input_dev *dev = evdev->handle.dev;
298 	struct input_absinfo abs;
299 	void __user *p = (void __user *)arg;
300 	int __user *ip = (int __user *)arg;
301 	int i, t, u, v;
302 
303 	if (!evdev->exist) return -ENODEV;
304 
305 	switch (cmd) {
306 
307 		case EVIOCGVERSION:
308 			return put_user(EV_VERSION, ip);
309 
310 		case EVIOCGID:
311 			return copy_to_user(p, &dev->id, sizeof(struct input_id)) ? -EFAULT : 0;
312 
313 		case EVIOCGKEYCODE:
314 			if (get_user(t, ip)) return -EFAULT;
315 			if (t < 0 || t >= dev->keycodemax || !dev->keycodesize) return -EINVAL;
316 			if (put_user(INPUT_KEYCODE(dev, t), ip + 1)) return -EFAULT;
317 			return 0;
318 
319 		case EVIOCSKEYCODE:
320 			if (get_user(t, ip)) return -EFAULT;
321 			if (t < 0 || t >= dev->keycodemax || !dev->keycodesize) return -EINVAL;
322 			if (get_user(v, ip + 1)) return -EFAULT;
323 			if (v < 0 || v > KEY_MAX) return -EINVAL;
324 			if (dev->keycodesize < sizeof(v) && (v >> (dev->keycodesize * 8))) return -EINVAL;
325 			u = SET_INPUT_KEYCODE(dev, t, v);
326 			clear_bit(u, dev->keybit);
327 			set_bit(v, dev->keybit);
328 			for (i = 0; i < dev->keycodemax; i++)
329 				if (INPUT_KEYCODE(dev,i) == u)
330 					set_bit(u, dev->keybit);
331 			return 0;
332 
333 		case EVIOCSFF:
334 			if (dev->upload_effect) {
335 				struct ff_effect effect;
336 				int err;
337 
338 				if (copy_from_user(&effect, p, sizeof(effect)))
339 					return -EFAULT;
340 				err = dev->upload_effect(dev, &effect);
341 				if (put_user(effect.id, &(((struct ff_effect __user *)arg)->id)))
342 					return -EFAULT;
343 				return err;
344 			}
345 			else return -ENOSYS;
346 
347 		case EVIOCRMFF:
348 			if (dev->erase_effect) {
349 				return dev->erase_effect(dev, (int)arg);
350 			}
351 			else return -ENOSYS;
352 
353 		case EVIOCGEFFECTS:
354 			if (put_user(dev->ff_effects_max, ip))
355 				return -EFAULT;
356 			return 0;
357 
358 		case EVIOCGRAB:
359 			if (arg) {
360 				if (evdev->grab)
361 					return -EBUSY;
362 				if (input_grab_device(&evdev->handle))
363 					return -EBUSY;
364 				evdev->grab = list;
365 				return 0;
366 			} else {
367 				if (evdev->grab != list)
368 					return -EINVAL;
369 				input_release_device(&evdev->handle);
370 				evdev->grab = NULL;
371 				return 0;
372 			}
373 
374 		default:
375 
376 			if (_IOC_TYPE(cmd) != 'E')
377 				return -EINVAL;
378 
379 			if (_IOC_DIR(cmd) == _IOC_READ) {
380 
381 				if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0,0))) {
382 
383 					long *bits;
384 					int len;
385 
386 					switch (_IOC_NR(cmd) & EV_MAX) {
387 						case      0: bits = dev->evbit;  len = EV_MAX;  break;
388 						case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
389 						case EV_REL: bits = dev->relbit; len = REL_MAX; break;
390 						case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
391 						case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
392 						case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
393 						case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
394 						case EV_FF:  bits = dev->ffbit;  len = FF_MAX;  break;
395 						case EV_SW:  bits = dev->swbit;  len = SW_MAX;  break;
396 						default: return -EINVAL;
397 					}
398 					len = NBITS(len) * sizeof(long);
399 					if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
400 					return copy_to_user(p, bits, len) ? -EFAULT : len;
401 				}
402 
403 				if (_IOC_NR(cmd) == _IOC_NR(EVIOCGKEY(0))) {
404 					int len;
405 					len = NBITS(KEY_MAX) * sizeof(long);
406 					if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
407 					return copy_to_user(p, dev->key, len) ? -EFAULT : len;
408 				}
409 
410 				if (_IOC_NR(cmd) == _IOC_NR(EVIOCGLED(0))) {
411 					int len;
412 					len = NBITS(LED_MAX) * sizeof(long);
413 					if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
414 					return copy_to_user(p, dev->led, len) ? -EFAULT : len;
415 				}
416 
417 				if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSND(0))) {
418 					int len;
419 					len = NBITS(SND_MAX) * sizeof(long);
420 					if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
421 					return copy_to_user(p, dev->snd, len) ? -EFAULT : len;
422 				}
423 
424 				if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSW(0))) {
425 					int len;
426 					len = NBITS(SW_MAX) * sizeof(long);
427 					if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
428 					return copy_to_user(p, dev->sw, len) ? -EFAULT : len;
429 				}
430 
431 				if (_IOC_NR(cmd) == _IOC_NR(EVIOCGNAME(0))) {
432 					int len;
433 					if (!dev->name) return -ENOENT;
434 					len = strlen(dev->name) + 1;
435 					if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
436 					return copy_to_user(p, dev->name, len) ? -EFAULT : len;
437 				}
438 
439 				if (_IOC_NR(cmd) == _IOC_NR(EVIOCGPHYS(0))) {
440 					int len;
441 					if (!dev->phys) return -ENOENT;
442 					len = strlen(dev->phys) + 1;
443 					if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
444 					return copy_to_user(p, dev->phys, len) ? -EFAULT : len;
445 				}
446 
447 				if (_IOC_NR(cmd) == _IOC_NR(EVIOCGUNIQ(0))) {
448 					int len;
449 					if (!dev->uniq) return -ENOENT;
450 					len = strlen(dev->uniq) + 1;
451 					if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
452 					return copy_to_user(p, dev->uniq, len) ? -EFAULT : len;
453 				}
454 
455 				if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
456 
457 					int t = _IOC_NR(cmd) & ABS_MAX;
458 
459 					abs.value = dev->abs[t];
460 					abs.minimum = dev->absmin[t];
461 					abs.maximum = dev->absmax[t];
462 					abs.fuzz = dev->absfuzz[t];
463 					abs.flat = dev->absflat[t];
464 
465 					if (copy_to_user(p, &abs, sizeof(struct input_absinfo)))
466 						return -EFAULT;
467 
468 					return 0;
469 				}
470 
471 			}
472 
473 			if (_IOC_DIR(cmd) == _IOC_WRITE) {
474 
475 				if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {
476 
477 					int t = _IOC_NR(cmd) & ABS_MAX;
478 
479 					if (copy_from_user(&abs, p, sizeof(struct input_absinfo)))
480 						return -EFAULT;
481 
482 					dev->abs[t] = abs.value;
483 					dev->absmin[t] = abs.minimum;
484 					dev->absmax[t] = abs.maximum;
485 					dev->absfuzz[t] = abs.fuzz;
486 					dev->absflat[t] = abs.flat;
487 
488 					return 0;
489 				}
490 			}
491 	}
492 	return -EINVAL;
493 }
494 
495 #ifdef CONFIG_COMPAT
496 
497 #define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8)
498 #define NBITS_COMPAT(x) ((((x)-1)/BITS_PER_LONG_COMPAT)+1)
499 #define OFF_COMPAT(x)  ((x)%BITS_PER_LONG_COMPAT)
500 #define BIT_COMPAT(x)  (1UL<<OFF_COMPAT(x))
501 #define LONG_COMPAT(x) ((x)/BITS_PER_LONG_COMPAT)
502 #define test_bit_compat(bit, array) ((array[LONG_COMPAT(bit)] >> OFF_COMPAT(bit)) & 1)
503 
504 #ifdef __BIG_ENDIAN
505 #define bit_to_user(bit, max) \
506 do { \
507 	int i; \
508 	int len = NBITS_COMPAT((max)) * sizeof(compat_long_t); \
509 	if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd); \
510 	for (i = 0; i < len / sizeof(compat_long_t); i++) \
511 		if (copy_to_user((compat_long_t __user *) p + i, \
512 				 (compat_long_t*) (bit) + i + 1 - ((i % 2) << 1), \
513 				 sizeof(compat_long_t))) \
514 			return -EFAULT; \
515 	return len; \
516 } while (0)
517 #else
518 #define bit_to_user(bit, max) \
519 do { \
520 	int len = NBITS_COMPAT((max)) * sizeof(compat_long_t); \
521 	if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd); \
522 	return copy_to_user(p, (bit), len) ? -EFAULT : len; \
523 } while (0)
524 #endif
525 
526 static long evdev_ioctl_compat(struct file *file, unsigned int cmd, unsigned long arg)
527 {
528 	struct evdev_list *list = file->private_data;
529 	struct evdev *evdev = list->evdev;
530 	struct input_dev *dev = evdev->handle.dev;
531 	struct input_absinfo abs;
532 	void __user *p = compat_ptr(arg);
533 
534 	if (!evdev->exist) return -ENODEV;
535 
536 	switch (cmd) {
537 
538 		case EVIOCGVERSION:
539 		case EVIOCGID:
540 		case EVIOCGKEYCODE:
541 		case EVIOCSKEYCODE:
542 		case EVIOCSFF:
543 		case EVIOCRMFF:
544 		case EVIOCGEFFECTS:
545 		case EVIOCGRAB:
546 			return evdev_ioctl(file, cmd, (unsigned long) p);
547 
548 		default:
549 
550 			if (_IOC_TYPE(cmd) != 'E')
551 				return -EINVAL;
552 
553 			if (_IOC_DIR(cmd) == _IOC_READ) {
554 
555 				if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0,0))) {
556 					long *bits;
557 					int max;
558 
559 					switch (_IOC_NR(cmd) & EV_MAX) {
560 						case      0: bits = dev->evbit;  max = EV_MAX;  break;
561 						case EV_KEY: bits = dev->keybit; max = KEY_MAX; break;
562 						case EV_REL: bits = dev->relbit; max = REL_MAX; break;
563 						case EV_ABS: bits = dev->absbit; max = ABS_MAX; break;
564 						case EV_MSC: bits = dev->mscbit; max = MSC_MAX; break;
565 						case EV_LED: bits = dev->ledbit; max = LED_MAX; break;
566 						case EV_SND: bits = dev->sndbit; max = SND_MAX; break;
567 						case EV_FF:  bits = dev->ffbit;  max = FF_MAX;  break;
568 						case EV_SW:  bits = dev->swbit;  max = SW_MAX;  break;
569 						default: return -EINVAL;
570 					}
571 					bit_to_user(bits, max);
572 				}
573 
574 				if (_IOC_NR(cmd) == _IOC_NR(EVIOCGKEY(0)))
575 					bit_to_user(dev->key, KEY_MAX);
576 
577 				if (_IOC_NR(cmd) == _IOC_NR(EVIOCGLED(0)))
578 					bit_to_user(dev->led, LED_MAX);
579 
580 				if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSND(0)))
581 					bit_to_user(dev->snd, SND_MAX);
582 
583 				if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSW(0)))
584 					bit_to_user(dev->sw, SW_MAX);
585 
586 				if (_IOC_NR(cmd) == _IOC_NR(EVIOCGNAME(0))) {
587 					int len;
588 					if (!dev->name) return -ENOENT;
589 					len = strlen(dev->name) + 1;
590 					if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
591 					return copy_to_user(p, dev->name, len) ? -EFAULT : len;
592 				}
593 
594 				if (_IOC_NR(cmd) == _IOC_NR(EVIOCGPHYS(0))) {
595 					int len;
596 					if (!dev->phys) return -ENOENT;
597 					len = strlen(dev->phys) + 1;
598 					if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
599 					return copy_to_user(p, dev->phys, len) ? -EFAULT : len;
600 				}
601 
602 				if (_IOC_NR(cmd) == _IOC_NR(EVIOCGUNIQ(0))) {
603 					int len;
604 					if (!dev->uniq) return -ENOENT;
605 					len = strlen(dev->uniq) + 1;
606 					if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
607 					return copy_to_user(p, dev->uniq, len) ? -EFAULT : len;
608 				}
609 
610 				if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
611 
612 					int t = _IOC_NR(cmd) & ABS_MAX;
613 
614 					abs.value = dev->abs[t];
615 					abs.minimum = dev->absmin[t];
616 					abs.maximum = dev->absmax[t];
617 					abs.fuzz = dev->absfuzz[t];
618 					abs.flat = dev->absflat[t];
619 
620 					if (copy_to_user(p, &abs, sizeof(struct input_absinfo)))
621 						return -EFAULT;
622 
623 					return 0;
624 				}
625 			}
626 
627 			if (_IOC_DIR(cmd) == _IOC_WRITE) {
628 
629 				if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {
630 
631 					int t = _IOC_NR(cmd) & ABS_MAX;
632 
633 					if (copy_from_user(&abs, p, sizeof(struct input_absinfo)))
634 						return -EFAULT;
635 
636 					dev->abs[t] = abs.value;
637 					dev->absmin[t] = abs.minimum;
638 					dev->absmax[t] = abs.maximum;
639 					dev->absfuzz[t] = abs.fuzz;
640 					dev->absflat[t] = abs.flat;
641 
642 					return 0;
643 				}
644 			}
645 	}
646 	return -EINVAL;
647 }
648 #endif
649 
650 static struct file_operations evdev_fops = {
651 	.owner =	THIS_MODULE,
652 	.read =		evdev_read,
653 	.write =	evdev_write,
654 	.poll =		evdev_poll,
655 	.open =		evdev_open,
656 	.release =	evdev_release,
657 	.unlocked_ioctl = evdev_ioctl,
658 #ifdef CONFIG_COMPAT
659 	.compat_ioctl =	evdev_ioctl_compat,
660 #endif
661 	.fasync =	evdev_fasync,
662 	.flush =	evdev_flush
663 };
664 
665 static struct input_handle *evdev_connect(struct input_handler *handler, struct input_dev *dev, struct input_device_id *id)
666 {
667 	struct evdev *evdev;
668 	struct class_device *cdev;
669 	int minor;
670 
671 	for (minor = 0; minor < EVDEV_MINORS && evdev_table[minor]; minor++);
672 	if (minor == EVDEV_MINORS) {
673 		printk(KERN_ERR "evdev: no more free evdev devices\n");
674 		return NULL;
675 	}
676 
677 	if (!(evdev = kmalloc(sizeof(struct evdev), GFP_KERNEL)))
678 		return NULL;
679 	memset(evdev, 0, sizeof(struct evdev));
680 
681 	INIT_LIST_HEAD(&evdev->list);
682 	init_waitqueue_head(&evdev->wait);
683 
684 	evdev->exist = 1;
685 	evdev->minor = minor;
686 	evdev->handle.dev = dev;
687 	evdev->handle.name = evdev->name;
688 	evdev->handle.handler = handler;
689 	evdev->handle.private = evdev;
690 	sprintf(evdev->name, "event%d", minor);
691 
692 	evdev_table[minor] = evdev;
693 
694 	cdev = class_device_create(&input_class, &dev->cdev,
695 			MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + minor),
696 			dev->cdev.dev, evdev->name);
697 
698 	/* temporary symlink to keep userspace happy */
699 	sysfs_create_link(&input_class.subsys.kset.kobj, &cdev->kobj,
700 			  evdev->name);
701 
702 	return &evdev->handle;
703 }
704 
705 static void evdev_disconnect(struct input_handle *handle)
706 {
707 	struct evdev *evdev = handle->private;
708 	struct evdev_list *list;
709 
710 	sysfs_remove_link(&input_class.subsys.kset.kobj, evdev->name);
711 	class_device_destroy(&input_class,
712 			MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + evdev->minor));
713 	evdev->exist = 0;
714 
715 	if (evdev->open) {
716 		input_close_device(handle);
717 		wake_up_interruptible(&evdev->wait);
718 		list_for_each_entry(list, &evdev->list, node)
719 			kill_fasync(&list->fasync, SIGIO, POLL_HUP);
720 	} else
721 		evdev_free(evdev);
722 }
723 
724 static struct input_device_id evdev_ids[] = {
725 	{ .driver_info = 1 },	/* Matches all devices */
726 	{ },			/* Terminating zero entry */
727 };
728 
729 MODULE_DEVICE_TABLE(input, evdev_ids);
730 
731 static struct input_handler evdev_handler = {
732 	.event =	evdev_event,
733 	.connect =	evdev_connect,
734 	.disconnect =	evdev_disconnect,
735 	.fops =		&evdev_fops,
736 	.minor =	EVDEV_MINOR_BASE,
737 	.name =		"evdev",
738 	.id_table =	evdev_ids,
739 };
740 
741 static int __init evdev_init(void)
742 {
743 	input_register_handler(&evdev_handler);
744 	return 0;
745 }
746 
747 static void __exit evdev_exit(void)
748 {
749 	input_unregister_handler(&evdev_handler);
750 }
751 
752 module_init(evdev_init);
753 module_exit(evdev_exit);
754 
755 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
756 MODULE_DESCRIPTION("Input driver event char devices");
757 MODULE_LICENSE("GPL");
758