xref: /openbmc/linux/drivers/input/joydev.c (revision b8bb76713ec50df2f11efee386e16f93d51e1076)
1 /*
2  * Joystick device driver for the input driver suite.
3  *
4  * Copyright (c) 1999-2002 Vojtech Pavlik
5  * Copyright (c) 1999 Colin Van Dyke
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 2 of the License, or
10  * (at your option) any later version.
11  */
12 
13 #include <asm/io.h>
14 #include <asm/system.h>
15 #include <linux/delay.h>
16 #include <linux/errno.h>
17 #include <linux/joystick.h>
18 #include <linux/input.h>
19 #include <linux/kernel.h>
20 #include <linux/major.h>
21 #include <linux/slab.h>
22 #include <linux/mm.h>
23 #include <linux/miscdevice.h>
24 #include <linux/module.h>
25 #include <linux/poll.h>
26 #include <linux/init.h>
27 #include <linux/device.h>
28 
29 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
30 MODULE_DESCRIPTION("Joystick device interfaces");
31 MODULE_SUPPORTED_DEVICE("input/js");
32 MODULE_LICENSE("GPL");
33 
34 #define JOYDEV_MINOR_BASE	0
35 #define JOYDEV_MINORS		16
36 #define JOYDEV_BUFFER_SIZE	64
37 
38 struct joydev {
39 	int exist;
40 	int open;
41 	int minor;
42 	char name[16];
43 	struct input_handle handle;
44 	wait_queue_head_t wait;
45 	struct list_head client_list;
46 	spinlock_t client_lock; /* protects client_list */
47 	struct mutex mutex;
48 	struct device dev;
49 
50 	struct js_corr corr[ABS_MAX + 1];
51 	struct JS_DATA_SAVE_TYPE glue;
52 	int nabs;
53 	int nkey;
54 	__u16 keymap[KEY_MAX - BTN_MISC + 1];
55 	__u16 keypam[KEY_MAX - BTN_MISC + 1];
56 	__u8 absmap[ABS_MAX + 1];
57 	__u8 abspam[ABS_MAX + 1];
58 	__s16 abs[ABS_MAX + 1];
59 };
60 
61 struct joydev_client {
62 	struct js_event buffer[JOYDEV_BUFFER_SIZE];
63 	int head;
64 	int tail;
65 	int startup;
66 	spinlock_t buffer_lock; /* protects access to buffer, head and tail */
67 	struct fasync_struct *fasync;
68 	struct joydev *joydev;
69 	struct list_head node;
70 };
71 
72 static struct joydev *joydev_table[JOYDEV_MINORS];
73 static DEFINE_MUTEX(joydev_table_mutex);
74 
75 static int joydev_correct(int value, struct js_corr *corr)
76 {
77 	switch (corr->type) {
78 
79 	case JS_CORR_NONE:
80 		break;
81 
82 	case JS_CORR_BROKEN:
83 		value = value > corr->coef[0] ? (value < corr->coef[1] ? 0 :
84 			((corr->coef[3] * (value - corr->coef[1])) >> 14)) :
85 			((corr->coef[2] * (value - corr->coef[0])) >> 14);
86 		break;
87 
88 	default:
89 		return 0;
90 	}
91 
92 	return value < -32767 ? -32767 : (value > 32767 ? 32767 : value);
93 }
94 
95 static void joydev_pass_event(struct joydev_client *client,
96 			      struct js_event *event)
97 {
98 	struct joydev *joydev = client->joydev;
99 
100 	/*
101 	 * IRQs already disabled, just acquire the lock
102 	 */
103 	spin_lock(&client->buffer_lock);
104 
105 	client->buffer[client->head] = *event;
106 
107 	if (client->startup == joydev->nabs + joydev->nkey) {
108 		client->head++;
109 		client->head &= JOYDEV_BUFFER_SIZE - 1;
110 		if (client->tail == client->head)
111 			client->startup = 0;
112 	}
113 
114 	spin_unlock(&client->buffer_lock);
115 
116 	kill_fasync(&client->fasync, SIGIO, POLL_IN);
117 }
118 
119 static void joydev_event(struct input_handle *handle,
120 			 unsigned int type, unsigned int code, int value)
121 {
122 	struct joydev *joydev = handle->private;
123 	struct joydev_client *client;
124 	struct js_event event;
125 
126 	switch (type) {
127 
128 	case EV_KEY:
129 		if (code < BTN_MISC || value == 2)
130 			return;
131 		event.type = JS_EVENT_BUTTON;
132 		event.number = joydev->keymap[code - BTN_MISC];
133 		event.value = value;
134 		break;
135 
136 	case EV_ABS:
137 		event.type = JS_EVENT_AXIS;
138 		event.number = joydev->absmap[code];
139 		event.value = joydev_correct(value,
140 					&joydev->corr[event.number]);
141 		if (event.value == joydev->abs[event.number])
142 			return;
143 		joydev->abs[event.number] = event.value;
144 		break;
145 
146 	default:
147 		return;
148 	}
149 
150 	event.time = jiffies_to_msecs(jiffies);
151 
152 	rcu_read_lock();
153 	list_for_each_entry_rcu(client, &joydev->client_list, node)
154 		joydev_pass_event(client, &event);
155 	rcu_read_unlock();
156 
157 	wake_up_interruptible(&joydev->wait);
158 }
159 
160 static int joydev_fasync(int fd, struct file *file, int on)
161 {
162 	struct joydev_client *client = file->private_data;
163 
164 	return fasync_helper(fd, file, on, &client->fasync);
165 }
166 
167 static void joydev_free(struct device *dev)
168 {
169 	struct joydev *joydev = container_of(dev, struct joydev, dev);
170 
171 	input_put_device(joydev->handle.dev);
172 	kfree(joydev);
173 }
174 
175 static void joydev_attach_client(struct joydev *joydev,
176 				 struct joydev_client *client)
177 {
178 	spin_lock(&joydev->client_lock);
179 	list_add_tail_rcu(&client->node, &joydev->client_list);
180 	spin_unlock(&joydev->client_lock);
181 	synchronize_rcu();
182 }
183 
184 static void joydev_detach_client(struct joydev *joydev,
185 				 struct joydev_client *client)
186 {
187 	spin_lock(&joydev->client_lock);
188 	list_del_rcu(&client->node);
189 	spin_unlock(&joydev->client_lock);
190 	synchronize_rcu();
191 }
192 
193 static int joydev_open_device(struct joydev *joydev)
194 {
195 	int retval;
196 
197 	retval = mutex_lock_interruptible(&joydev->mutex);
198 	if (retval)
199 		return retval;
200 
201 	if (!joydev->exist)
202 		retval = -ENODEV;
203 	else if (!joydev->open++) {
204 		retval = input_open_device(&joydev->handle);
205 		if (retval)
206 			joydev->open--;
207 	}
208 
209 	mutex_unlock(&joydev->mutex);
210 	return retval;
211 }
212 
213 static void joydev_close_device(struct joydev *joydev)
214 {
215 	mutex_lock(&joydev->mutex);
216 
217 	if (joydev->exist && !--joydev->open)
218 		input_close_device(&joydev->handle);
219 
220 	mutex_unlock(&joydev->mutex);
221 }
222 
223 /*
224  * Wake up users waiting for IO so they can disconnect from
225  * dead device.
226  */
227 static void joydev_hangup(struct joydev *joydev)
228 {
229 	struct joydev_client *client;
230 
231 	spin_lock(&joydev->client_lock);
232 	list_for_each_entry(client, &joydev->client_list, node)
233 		kill_fasync(&client->fasync, SIGIO, POLL_HUP);
234 	spin_unlock(&joydev->client_lock);
235 
236 	wake_up_interruptible(&joydev->wait);
237 }
238 
239 static int joydev_release(struct inode *inode, struct file *file)
240 {
241 	struct joydev_client *client = file->private_data;
242 	struct joydev *joydev = client->joydev;
243 
244 	joydev_detach_client(joydev, client);
245 	kfree(client);
246 
247 	joydev_close_device(joydev);
248 	put_device(&joydev->dev);
249 
250 	return 0;
251 }
252 
253 static int joydev_open(struct inode *inode, struct file *file)
254 {
255 	struct joydev_client *client;
256 	struct joydev *joydev;
257 	int i = iminor(inode) - JOYDEV_MINOR_BASE;
258 	int error;
259 
260 	if (i >= JOYDEV_MINORS)
261 		return -ENODEV;
262 
263 	error = mutex_lock_interruptible(&joydev_table_mutex);
264 	if (error)
265 		return error;
266 	joydev = joydev_table[i];
267 	if (joydev)
268 		get_device(&joydev->dev);
269 	mutex_unlock(&joydev_table_mutex);
270 
271 	if (!joydev)
272 		return -ENODEV;
273 
274 	client = kzalloc(sizeof(struct joydev_client), GFP_KERNEL);
275 	if (!client) {
276 		error = -ENOMEM;
277 		goto err_put_joydev;
278 	}
279 
280 	spin_lock_init(&client->buffer_lock);
281 	client->joydev = joydev;
282 	joydev_attach_client(joydev, client);
283 
284 	error = joydev_open_device(joydev);
285 	if (error)
286 		goto err_free_client;
287 
288 	file->private_data = client;
289 	return 0;
290 
291  err_free_client:
292 	joydev_detach_client(joydev, client);
293 	kfree(client);
294  err_put_joydev:
295 	put_device(&joydev->dev);
296 	return error;
297 }
298 
299 static int joydev_generate_startup_event(struct joydev_client *client,
300 					 struct input_dev *input,
301 					 struct js_event *event)
302 {
303 	struct joydev *joydev = client->joydev;
304 	int have_event;
305 
306 	spin_lock_irq(&client->buffer_lock);
307 
308 	have_event = client->startup < joydev->nabs + joydev->nkey;
309 
310 	if (have_event) {
311 
312 		event->time = jiffies_to_msecs(jiffies);
313 		if (client->startup < joydev->nkey) {
314 			event->type = JS_EVENT_BUTTON | JS_EVENT_INIT;
315 			event->number = client->startup;
316 			event->value = !!test_bit(joydev->keypam[event->number],
317 						  input->key);
318 		} else {
319 			event->type = JS_EVENT_AXIS | JS_EVENT_INIT;
320 			event->number = client->startup - joydev->nkey;
321 			event->value = joydev->abs[event->number];
322 		}
323 		client->startup++;
324 	}
325 
326 	spin_unlock_irq(&client->buffer_lock);
327 
328 	return have_event;
329 }
330 
331 static int joydev_fetch_next_event(struct joydev_client *client,
332 				   struct js_event *event)
333 {
334 	int have_event;
335 
336 	spin_lock_irq(&client->buffer_lock);
337 
338 	have_event = client->head != client->tail;
339 	if (have_event) {
340 		*event = client->buffer[client->tail++];
341 		client->tail &= JOYDEV_BUFFER_SIZE - 1;
342 	}
343 
344 	spin_unlock_irq(&client->buffer_lock);
345 
346 	return have_event;
347 }
348 
349 /*
350  * Old joystick interface
351  */
352 static ssize_t joydev_0x_read(struct joydev_client *client,
353 			      struct input_dev *input,
354 			      char __user *buf)
355 {
356 	struct joydev *joydev = client->joydev;
357 	struct JS_DATA_TYPE data;
358 	int i;
359 
360 	spin_lock_irq(&input->event_lock);
361 
362 	/*
363 	 * Get device state
364 	 */
365 	for (data.buttons = i = 0; i < 32 && i < joydev->nkey; i++)
366 		data.buttons |=
367 			test_bit(joydev->keypam[i], input->key) ? (1 << i) : 0;
368 	data.x = (joydev->abs[0] / 256 + 128) >> joydev->glue.JS_CORR.x;
369 	data.y = (joydev->abs[1] / 256 + 128) >> joydev->glue.JS_CORR.y;
370 
371 	/*
372 	 * Reset reader's event queue
373 	 */
374 	spin_lock(&client->buffer_lock);
375 	client->startup = 0;
376 	client->tail = client->head;
377 	spin_unlock(&client->buffer_lock);
378 
379 	spin_unlock_irq(&input->event_lock);
380 
381 	if (copy_to_user(buf, &data, sizeof(struct JS_DATA_TYPE)))
382 		return -EFAULT;
383 
384 	return sizeof(struct JS_DATA_TYPE);
385 }
386 
387 static inline int joydev_data_pending(struct joydev_client *client)
388 {
389 	struct joydev *joydev = client->joydev;
390 
391 	return client->startup < joydev->nabs + joydev->nkey ||
392 		client->head != client->tail;
393 }
394 
395 static ssize_t joydev_read(struct file *file, char __user *buf,
396 			   size_t count, loff_t *ppos)
397 {
398 	struct joydev_client *client = file->private_data;
399 	struct joydev *joydev = client->joydev;
400 	struct input_dev *input = joydev->handle.dev;
401 	struct js_event event;
402 	int retval;
403 
404 	if (!joydev->exist)
405 		return -ENODEV;
406 
407 	if (count < sizeof(struct js_event))
408 		return -EINVAL;
409 
410 	if (count == sizeof(struct JS_DATA_TYPE))
411 		return joydev_0x_read(client, input, buf);
412 
413 	if (!joydev_data_pending(client) && (file->f_flags & O_NONBLOCK))
414 		return -EAGAIN;
415 
416 	retval = wait_event_interruptible(joydev->wait,
417 			!joydev->exist || joydev_data_pending(client));
418 	if (retval)
419 		return retval;
420 
421 	if (!joydev->exist)
422 		return -ENODEV;
423 
424 	while (retval + sizeof(struct js_event) <= count &&
425 	       joydev_generate_startup_event(client, input, &event)) {
426 
427 		if (copy_to_user(buf + retval, &event, sizeof(struct js_event)))
428 			return -EFAULT;
429 
430 		retval += sizeof(struct js_event);
431 	}
432 
433 	while (retval + sizeof(struct js_event) <= count &&
434 	       joydev_fetch_next_event(client, &event)) {
435 
436 		if (copy_to_user(buf + retval, &event, sizeof(struct js_event)))
437 			return -EFAULT;
438 
439 		retval += sizeof(struct js_event);
440 	}
441 
442 	return retval;
443 }
444 
445 /* No kernel lock - fine */
446 static unsigned int joydev_poll(struct file *file, poll_table *wait)
447 {
448 	struct joydev_client *client = file->private_data;
449 	struct joydev *joydev = client->joydev;
450 
451 	poll_wait(file, &joydev->wait, wait);
452 	return (joydev_data_pending(client) ? (POLLIN | POLLRDNORM) : 0) |
453 		(joydev->exist ?  0 : (POLLHUP | POLLERR));
454 }
455 
456 static int joydev_ioctl_common(struct joydev *joydev,
457 				unsigned int cmd, void __user *argp)
458 {
459 	struct input_dev *dev = joydev->handle.dev;
460 	int i, j;
461 
462 	switch (cmd) {
463 
464 	case JS_SET_CAL:
465 		return copy_from_user(&joydev->glue.JS_CORR, argp,
466 				sizeof(joydev->glue.JS_CORR)) ? -EFAULT : 0;
467 
468 	case JS_GET_CAL:
469 		return copy_to_user(argp, &joydev->glue.JS_CORR,
470 				sizeof(joydev->glue.JS_CORR)) ? -EFAULT : 0;
471 
472 	case JS_SET_TIMEOUT:
473 		return get_user(joydev->glue.JS_TIMEOUT, (s32 __user *) argp);
474 
475 	case JS_GET_TIMEOUT:
476 		return put_user(joydev->glue.JS_TIMEOUT, (s32 __user *) argp);
477 
478 	case JSIOCGVERSION:
479 		return put_user(JS_VERSION, (__u32 __user *) argp);
480 
481 	case JSIOCGAXES:
482 		return put_user(joydev->nabs, (__u8 __user *) argp);
483 
484 	case JSIOCGBUTTONS:
485 		return put_user(joydev->nkey, (__u8 __user *) argp);
486 
487 	case JSIOCSCORR:
488 		if (copy_from_user(joydev->corr, argp,
489 			      sizeof(joydev->corr[0]) * joydev->nabs))
490 		    return -EFAULT;
491 
492 		for (i = 0; i < joydev->nabs; i++) {
493 			j = joydev->abspam[i];
494 			joydev->abs[i] = joydev_correct(dev->abs[j],
495 							&joydev->corr[i]);
496 		}
497 		return 0;
498 
499 	case JSIOCGCORR:
500 		return copy_to_user(argp, joydev->corr,
501 			sizeof(joydev->corr[0]) * joydev->nabs) ? -EFAULT : 0;
502 
503 	case JSIOCSAXMAP:
504 		if (copy_from_user(joydev->abspam, argp,
505 				   sizeof(__u8) * (ABS_MAX + 1)))
506 			return -EFAULT;
507 
508 		for (i = 0; i < joydev->nabs; i++) {
509 			if (joydev->abspam[i] > ABS_MAX)
510 				return -EINVAL;
511 			joydev->absmap[joydev->abspam[i]] = i;
512 		}
513 		return 0;
514 
515 	case JSIOCGAXMAP:
516 		return copy_to_user(argp, joydev->abspam,
517 			sizeof(__u8) * (ABS_MAX + 1)) ? -EFAULT : 0;
518 
519 	case JSIOCSBTNMAP:
520 		if (copy_from_user(joydev->keypam, argp,
521 				   sizeof(__u16) * (KEY_MAX - BTN_MISC + 1)))
522 			return -EFAULT;
523 
524 		for (i = 0; i < joydev->nkey; i++) {
525 			if (joydev->keypam[i] > KEY_MAX ||
526 			    joydev->keypam[i] < BTN_MISC)
527 				return -EINVAL;
528 			joydev->keymap[joydev->keypam[i] - BTN_MISC] = i;
529 		}
530 
531 		return 0;
532 
533 	case JSIOCGBTNMAP:
534 		return copy_to_user(argp, joydev->keypam,
535 			sizeof(__u16) * (KEY_MAX - BTN_MISC + 1)) ? -EFAULT : 0;
536 
537 	default:
538 		if ((cmd & ~IOCSIZE_MASK) == JSIOCGNAME(0)) {
539 			int len;
540 			if (!dev->name)
541 				return 0;
542 			len = strlen(dev->name) + 1;
543 			if (len > _IOC_SIZE(cmd))
544 				len = _IOC_SIZE(cmd);
545 			if (copy_to_user(argp, dev->name, len))
546 				return -EFAULT;
547 			return len;
548 		}
549 	}
550 	return -EINVAL;
551 }
552 
553 #ifdef CONFIG_COMPAT
554 static long joydev_compat_ioctl(struct file *file,
555 				unsigned int cmd, unsigned long arg)
556 {
557 	struct joydev_client *client = file->private_data;
558 	struct joydev *joydev = client->joydev;
559 	void __user *argp = (void __user *)arg;
560 	s32 tmp32;
561 	struct JS_DATA_SAVE_TYPE_32 ds32;
562 	int retval;
563 
564 	retval = mutex_lock_interruptible(&joydev->mutex);
565 	if (retval)
566 		return retval;
567 
568 	if (!joydev->exist) {
569 		retval = -ENODEV;
570 		goto out;
571 	}
572 
573 	switch (cmd) {
574 
575 	case JS_SET_TIMELIMIT:
576 		retval = get_user(tmp32, (s32 __user *) arg);
577 		if (retval == 0)
578 			joydev->glue.JS_TIMELIMIT = tmp32;
579 		break;
580 
581 	case JS_GET_TIMELIMIT:
582 		tmp32 = joydev->glue.JS_TIMELIMIT;
583 		retval = put_user(tmp32, (s32 __user *) arg);
584 		break;
585 
586 	case JS_SET_ALL:
587 		retval = copy_from_user(&ds32, argp,
588 					sizeof(ds32)) ? -EFAULT : 0;
589 		if (retval == 0) {
590 			joydev->glue.JS_TIMEOUT    = ds32.JS_TIMEOUT;
591 			joydev->glue.BUSY          = ds32.BUSY;
592 			joydev->glue.JS_EXPIRETIME = ds32.JS_EXPIRETIME;
593 			joydev->glue.JS_TIMELIMIT  = ds32.JS_TIMELIMIT;
594 			joydev->glue.JS_SAVE       = ds32.JS_SAVE;
595 			joydev->glue.JS_CORR       = ds32.JS_CORR;
596 		}
597 		break;
598 
599 	case JS_GET_ALL:
600 		ds32.JS_TIMEOUT    = joydev->glue.JS_TIMEOUT;
601 		ds32.BUSY          = joydev->glue.BUSY;
602 		ds32.JS_EXPIRETIME = joydev->glue.JS_EXPIRETIME;
603 		ds32.JS_TIMELIMIT  = joydev->glue.JS_TIMELIMIT;
604 		ds32.JS_SAVE       = joydev->glue.JS_SAVE;
605 		ds32.JS_CORR       = joydev->glue.JS_CORR;
606 
607 		retval = copy_to_user(argp, &ds32, sizeof(ds32)) ? -EFAULT : 0;
608 		break;
609 
610 	default:
611 		retval = joydev_ioctl_common(joydev, cmd, argp);
612 		break;
613 	}
614 
615  out:
616 	mutex_unlock(&joydev->mutex);
617 	return retval;
618 }
619 #endif /* CONFIG_COMPAT */
620 
621 static long joydev_ioctl(struct file *file,
622 			 unsigned int cmd, unsigned long arg)
623 {
624 	struct joydev_client *client = file->private_data;
625 	struct joydev *joydev = client->joydev;
626 	void __user *argp = (void __user *)arg;
627 	int retval;
628 
629 	retval = mutex_lock_interruptible(&joydev->mutex);
630 	if (retval)
631 		return retval;
632 
633 	if (!joydev->exist) {
634 		retval = -ENODEV;
635 		goto out;
636 	}
637 
638 	switch (cmd) {
639 
640 	case JS_SET_TIMELIMIT:
641 		retval = get_user(joydev->glue.JS_TIMELIMIT,
642 				  (long __user *) arg);
643 		break;
644 
645 	case JS_GET_TIMELIMIT:
646 		retval = put_user(joydev->glue.JS_TIMELIMIT,
647 				  (long __user *) arg);
648 		break;
649 
650 	case JS_SET_ALL:
651 		retval = copy_from_user(&joydev->glue, argp,
652 					sizeof(joydev->glue)) ? -EFAULT: 0;
653 		break;
654 
655 	case JS_GET_ALL:
656 		retval = copy_to_user(argp, &joydev->glue,
657 				      sizeof(joydev->glue)) ? -EFAULT : 0;
658 		break;
659 
660 	default:
661 		retval = joydev_ioctl_common(joydev, cmd, argp);
662 		break;
663 	}
664  out:
665 	mutex_unlock(&joydev->mutex);
666 	return retval;
667 }
668 
669 static const struct file_operations joydev_fops = {
670 	.owner		= THIS_MODULE,
671 	.read		= joydev_read,
672 	.poll		= joydev_poll,
673 	.open		= joydev_open,
674 	.release	= joydev_release,
675 	.unlocked_ioctl	= joydev_ioctl,
676 #ifdef CONFIG_COMPAT
677 	.compat_ioctl	= joydev_compat_ioctl,
678 #endif
679 	.fasync		= joydev_fasync,
680 };
681 
682 static int joydev_install_chrdev(struct joydev *joydev)
683 {
684 	joydev_table[joydev->minor] = joydev;
685 	return 0;
686 }
687 
688 static void joydev_remove_chrdev(struct joydev *joydev)
689 {
690 	mutex_lock(&joydev_table_mutex);
691 	joydev_table[joydev->minor] = NULL;
692 	mutex_unlock(&joydev_table_mutex);
693 }
694 
695 /*
696  * Mark device non-existant. This disables writes, ioctls and
697  * prevents new users from opening the device. Already posted
698  * blocking reads will stay, however new ones will fail.
699  */
700 static void joydev_mark_dead(struct joydev *joydev)
701 {
702 	mutex_lock(&joydev->mutex);
703 	joydev->exist = 0;
704 	mutex_unlock(&joydev->mutex);
705 }
706 
707 static void joydev_cleanup(struct joydev *joydev)
708 {
709 	struct input_handle *handle = &joydev->handle;
710 
711 	joydev_mark_dead(joydev);
712 	joydev_hangup(joydev);
713 	joydev_remove_chrdev(joydev);
714 
715 	/* joydev is marked dead so noone else accesses joydev->open */
716 	if (joydev->open)
717 		input_close_device(handle);
718 }
719 
720 static int joydev_connect(struct input_handler *handler, struct input_dev *dev,
721 			  const struct input_device_id *id)
722 {
723 	struct joydev *joydev;
724 	int i, j, t, minor;
725 	int error;
726 
727 	for (minor = 0; minor < JOYDEV_MINORS; minor++)
728 		if (!joydev_table[minor])
729 			break;
730 
731 	if (minor == JOYDEV_MINORS) {
732 		printk(KERN_ERR "joydev: no more free joydev devices\n");
733 		return -ENFILE;
734 	}
735 
736 	joydev = kzalloc(sizeof(struct joydev), GFP_KERNEL);
737 	if (!joydev)
738 		return -ENOMEM;
739 
740 	INIT_LIST_HEAD(&joydev->client_list);
741 	spin_lock_init(&joydev->client_lock);
742 	mutex_init(&joydev->mutex);
743 	init_waitqueue_head(&joydev->wait);
744 
745 	snprintf(joydev->name, sizeof(joydev->name), "js%d", minor);
746 	joydev->exist = 1;
747 	joydev->minor = minor;
748 
749 	joydev->exist = 1;
750 	joydev->handle.dev = input_get_device(dev);
751 	joydev->handle.name = joydev->name;
752 	joydev->handle.handler = handler;
753 	joydev->handle.private = joydev;
754 
755 	for (i = 0; i < ABS_MAX + 1; i++)
756 		if (test_bit(i, dev->absbit)) {
757 			joydev->absmap[i] = joydev->nabs;
758 			joydev->abspam[joydev->nabs] = i;
759 			joydev->nabs++;
760 		}
761 
762 	for (i = BTN_JOYSTICK - BTN_MISC; i < KEY_MAX - BTN_MISC + 1; i++)
763 		if (test_bit(i + BTN_MISC, dev->keybit)) {
764 			joydev->keymap[i] = joydev->nkey;
765 			joydev->keypam[joydev->nkey] = i + BTN_MISC;
766 			joydev->nkey++;
767 		}
768 
769 	for (i = 0; i < BTN_JOYSTICK - BTN_MISC; i++)
770 		if (test_bit(i + BTN_MISC, dev->keybit)) {
771 			joydev->keymap[i] = joydev->nkey;
772 			joydev->keypam[joydev->nkey] = i + BTN_MISC;
773 			joydev->nkey++;
774 		}
775 
776 	for (i = 0; i < joydev->nabs; i++) {
777 		j = joydev->abspam[i];
778 		if (dev->absmax[j] == dev->absmin[j]) {
779 			joydev->corr[i].type = JS_CORR_NONE;
780 			joydev->abs[i] = dev->abs[j];
781 			continue;
782 		}
783 		joydev->corr[i].type = JS_CORR_BROKEN;
784 		joydev->corr[i].prec = dev->absfuzz[j];
785 		joydev->corr[i].coef[0] =
786 			(dev->absmax[j] + dev->absmin[j]) / 2 - dev->absflat[j];
787 		joydev->corr[i].coef[1] =
788 			(dev->absmax[j] + dev->absmin[j]) / 2 + dev->absflat[j];
789 
790 		t = (dev->absmax[j] - dev->absmin[j]) / 2 - 2 * dev->absflat[j];
791 		if (t) {
792 			joydev->corr[i].coef[2] = (1 << 29) / t;
793 			joydev->corr[i].coef[3] = (1 << 29) / t;
794 
795 			joydev->abs[i] = joydev_correct(dev->abs[j],
796 							joydev->corr + i);
797 		}
798 	}
799 
800 	dev_set_name(&joydev->dev, joydev->name);
801 	joydev->dev.devt = MKDEV(INPUT_MAJOR, JOYDEV_MINOR_BASE + minor);
802 	joydev->dev.class = &input_class;
803 	joydev->dev.parent = &dev->dev;
804 	joydev->dev.release = joydev_free;
805 	device_initialize(&joydev->dev);
806 
807 	error = input_register_handle(&joydev->handle);
808 	if (error)
809 		goto err_free_joydev;
810 
811 	error = joydev_install_chrdev(joydev);
812 	if (error)
813 		goto err_unregister_handle;
814 
815 	error = device_add(&joydev->dev);
816 	if (error)
817 		goto err_cleanup_joydev;
818 
819 	return 0;
820 
821  err_cleanup_joydev:
822 	joydev_cleanup(joydev);
823  err_unregister_handle:
824 	input_unregister_handle(&joydev->handle);
825  err_free_joydev:
826 	put_device(&joydev->dev);
827 	return error;
828 }
829 
830 static void joydev_disconnect(struct input_handle *handle)
831 {
832 	struct joydev *joydev = handle->private;
833 
834 	device_del(&joydev->dev);
835 	joydev_cleanup(joydev);
836 	input_unregister_handle(handle);
837 	put_device(&joydev->dev);
838 }
839 
840 static const struct input_device_id joydev_blacklist[] = {
841 	{
842 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
843 				INPUT_DEVICE_ID_MATCH_KEYBIT,
844 		.evbit = { BIT_MASK(EV_KEY) },
845 		.keybit = { [BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH) },
846 	},	/* Avoid itouchpads, touchscreens and tablets */
847 	{ }	/* Terminating entry */
848 };
849 
850 static const struct input_device_id joydev_ids[] = {
851 	{
852 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
853 				INPUT_DEVICE_ID_MATCH_ABSBIT,
854 		.evbit = { BIT_MASK(EV_ABS) },
855 		.absbit = { BIT_MASK(ABS_X) },
856 	},
857 	{
858 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
859 				INPUT_DEVICE_ID_MATCH_ABSBIT,
860 		.evbit = { BIT_MASK(EV_ABS) },
861 		.absbit = { BIT_MASK(ABS_WHEEL) },
862 	},
863 	{
864 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
865 				INPUT_DEVICE_ID_MATCH_ABSBIT,
866 		.evbit = { BIT_MASK(EV_ABS) },
867 		.absbit = { BIT_MASK(ABS_THROTTLE) },
868 	},
869 	{ }	/* Terminating entry */
870 };
871 
872 MODULE_DEVICE_TABLE(input, joydev_ids);
873 
874 static struct input_handler joydev_handler = {
875 	.event		= joydev_event,
876 	.connect	= joydev_connect,
877 	.disconnect	= joydev_disconnect,
878 	.fops		= &joydev_fops,
879 	.minor		= JOYDEV_MINOR_BASE,
880 	.name		= "joydev",
881 	.id_table	= joydev_ids,
882 	.blacklist	= joydev_blacklist,
883 };
884 
885 static int __init joydev_init(void)
886 {
887 	return input_register_handler(&joydev_handler);
888 }
889 
890 static void __exit joydev_exit(void)
891 {
892 	input_unregister_handler(&joydev_handler);
893 }
894 
895 module_init(joydev_init);
896 module_exit(joydev_exit);
897