xref: /openbmc/linux/drivers/input/joydev.c (revision a09d2831)
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/sched.h>
22 #include <linux/slab.h>
23 #include <linux/mm.h>
24 #include <linux/miscdevice.h>
25 #include <linux/module.h>
26 #include <linux/poll.h>
27 #include <linux/init.h>
28 #include <linux/device.h>
29 
30 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
31 MODULE_DESCRIPTION("Joystick device interfaces");
32 MODULE_SUPPORTED_DEVICE("input/js");
33 MODULE_LICENSE("GPL");
34 
35 #define JOYDEV_MINOR_BASE	0
36 #define JOYDEV_MINORS		16
37 #define JOYDEV_BUFFER_SIZE	64
38 
39 struct joydev {
40 	int exist;
41 	int open;
42 	int minor;
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_handle_JSIOCSAXMAP(struct joydev *joydev,
457 				     void __user *argp, size_t len)
458 {
459 	__u8 *abspam;
460 	int i;
461 	int retval = 0;
462 
463 	len = min(len, sizeof(joydev->abspam));
464 
465 	/* Validate the map. */
466 	abspam = kmalloc(len, GFP_KERNEL);
467 	if (!abspam)
468 		return -ENOMEM;
469 
470 	if (copy_from_user(abspam, argp, len)) {
471 		retval = -EFAULT;
472 		goto out;
473 	}
474 
475 	for (i = 0; i < joydev->nabs; i++) {
476 		if (abspam[i] > ABS_MAX) {
477 			retval = -EINVAL;
478 			goto out;
479 		}
480 	}
481 
482 	memcpy(joydev->abspam, abspam, len);
483 
484  out:
485 	kfree(abspam);
486 	return retval;
487 }
488 
489 static int joydev_handle_JSIOCSBTNMAP(struct joydev *joydev,
490 				      void __user *argp, size_t len)
491 {
492 	__u16 *keypam;
493 	int i;
494 	int retval = 0;
495 
496 	len = min(len, sizeof(joydev->keypam));
497 
498 	/* Validate the map. */
499 	keypam = kmalloc(len, GFP_KERNEL);
500 	if (!keypam)
501 		return -ENOMEM;
502 
503 	if (copy_from_user(keypam, argp, len)) {
504 		retval = -EFAULT;
505 		goto out;
506 	}
507 
508 	for (i = 0; i < joydev->nkey; i++) {
509 		if (keypam[i] > KEY_MAX || keypam[i] < BTN_MISC) {
510 			retval = -EINVAL;
511 			goto out;
512 		}
513 	}
514 
515 	memcpy(joydev->keypam, keypam, len);
516 
517 	for (i = 0; i < joydev->nkey; i++)
518 		joydev->keymap[keypam[i] - BTN_MISC] = i;
519 
520  out:
521 	kfree(keypam);
522 	return retval;
523 }
524 
525 
526 static int joydev_ioctl_common(struct joydev *joydev,
527 				unsigned int cmd, void __user *argp)
528 {
529 	struct input_dev *dev = joydev->handle.dev;
530 	size_t len;
531 	int i, j;
532 	const char *name;
533 
534 	/* Process fixed-sized commands. */
535 	switch (cmd) {
536 
537 	case JS_SET_CAL:
538 		return copy_from_user(&joydev->glue.JS_CORR, argp,
539 				sizeof(joydev->glue.JS_CORR)) ? -EFAULT : 0;
540 
541 	case JS_GET_CAL:
542 		return copy_to_user(argp, &joydev->glue.JS_CORR,
543 				sizeof(joydev->glue.JS_CORR)) ? -EFAULT : 0;
544 
545 	case JS_SET_TIMEOUT:
546 		return get_user(joydev->glue.JS_TIMEOUT, (s32 __user *) argp);
547 
548 	case JS_GET_TIMEOUT:
549 		return put_user(joydev->glue.JS_TIMEOUT, (s32 __user *) argp);
550 
551 	case JSIOCGVERSION:
552 		return put_user(JS_VERSION, (__u32 __user *) argp);
553 
554 	case JSIOCGAXES:
555 		return put_user(joydev->nabs, (__u8 __user *) argp);
556 
557 	case JSIOCGBUTTONS:
558 		return put_user(joydev->nkey, (__u8 __user *) argp);
559 
560 	case JSIOCSCORR:
561 		if (copy_from_user(joydev->corr, argp,
562 			      sizeof(joydev->corr[0]) * joydev->nabs))
563 		    return -EFAULT;
564 
565 		for (i = 0; i < joydev->nabs; i++) {
566 			j = joydev->abspam[i];
567 			joydev->abs[i] = joydev_correct(dev->abs[j],
568 							&joydev->corr[i]);
569 		}
570 		return 0;
571 
572 	case JSIOCGCORR:
573 		return copy_to_user(argp, joydev->corr,
574 			sizeof(joydev->corr[0]) * joydev->nabs) ? -EFAULT : 0;
575 
576 	}
577 
578 	/*
579 	 * Process variable-sized commands (the axis and button map commands
580 	 * are considered variable-sized to decouple them from the values of
581 	 * ABS_MAX and KEY_MAX).
582 	 */
583 	switch (cmd & ~IOCSIZE_MASK) {
584 
585 	case (JSIOCSAXMAP & ~IOCSIZE_MASK):
586 		return joydev_handle_JSIOCSAXMAP(joydev, argp, _IOC_SIZE(cmd));
587 
588 	case (JSIOCGAXMAP & ~IOCSIZE_MASK):
589 		len = min_t(size_t, _IOC_SIZE(cmd), sizeof(joydev->abspam));
590 		return copy_to_user(argp, joydev->abspam, len) ? -EFAULT : len;
591 
592 	case (JSIOCSBTNMAP & ~IOCSIZE_MASK):
593 		return joydev_handle_JSIOCSBTNMAP(joydev, argp, _IOC_SIZE(cmd));
594 
595 	case (JSIOCGBTNMAP & ~IOCSIZE_MASK):
596 		len = min_t(size_t, _IOC_SIZE(cmd), sizeof(joydev->keypam));
597 		return copy_to_user(argp, joydev->keypam, len) ? -EFAULT : len;
598 
599 	case JSIOCGNAME(0):
600 		name = dev->name;
601 		if (!name)
602 			return 0;
603 
604 		len = min_t(size_t, _IOC_SIZE(cmd), strlen(name) + 1);
605 		return copy_to_user(argp, name, len) ? -EFAULT : len;
606 	}
607 
608 	return -EINVAL;
609 }
610 
611 #ifdef CONFIG_COMPAT
612 static long joydev_compat_ioctl(struct file *file,
613 				unsigned int cmd, unsigned long arg)
614 {
615 	struct joydev_client *client = file->private_data;
616 	struct joydev *joydev = client->joydev;
617 	void __user *argp = (void __user *)arg;
618 	s32 tmp32;
619 	struct JS_DATA_SAVE_TYPE_32 ds32;
620 	int retval;
621 
622 	retval = mutex_lock_interruptible(&joydev->mutex);
623 	if (retval)
624 		return retval;
625 
626 	if (!joydev->exist) {
627 		retval = -ENODEV;
628 		goto out;
629 	}
630 
631 	switch (cmd) {
632 
633 	case JS_SET_TIMELIMIT:
634 		retval = get_user(tmp32, (s32 __user *) arg);
635 		if (retval == 0)
636 			joydev->glue.JS_TIMELIMIT = tmp32;
637 		break;
638 
639 	case JS_GET_TIMELIMIT:
640 		tmp32 = joydev->glue.JS_TIMELIMIT;
641 		retval = put_user(tmp32, (s32 __user *) arg);
642 		break;
643 
644 	case JS_SET_ALL:
645 		retval = copy_from_user(&ds32, argp,
646 					sizeof(ds32)) ? -EFAULT : 0;
647 		if (retval == 0) {
648 			joydev->glue.JS_TIMEOUT    = ds32.JS_TIMEOUT;
649 			joydev->glue.BUSY          = ds32.BUSY;
650 			joydev->glue.JS_EXPIRETIME = ds32.JS_EXPIRETIME;
651 			joydev->glue.JS_TIMELIMIT  = ds32.JS_TIMELIMIT;
652 			joydev->glue.JS_SAVE       = ds32.JS_SAVE;
653 			joydev->glue.JS_CORR       = ds32.JS_CORR;
654 		}
655 		break;
656 
657 	case JS_GET_ALL:
658 		ds32.JS_TIMEOUT    = joydev->glue.JS_TIMEOUT;
659 		ds32.BUSY          = joydev->glue.BUSY;
660 		ds32.JS_EXPIRETIME = joydev->glue.JS_EXPIRETIME;
661 		ds32.JS_TIMELIMIT  = joydev->glue.JS_TIMELIMIT;
662 		ds32.JS_SAVE       = joydev->glue.JS_SAVE;
663 		ds32.JS_CORR       = joydev->glue.JS_CORR;
664 
665 		retval = copy_to_user(argp, &ds32, sizeof(ds32)) ? -EFAULT : 0;
666 		break;
667 
668 	default:
669 		retval = joydev_ioctl_common(joydev, cmd, argp);
670 		break;
671 	}
672 
673  out:
674 	mutex_unlock(&joydev->mutex);
675 	return retval;
676 }
677 #endif /* CONFIG_COMPAT */
678 
679 static long joydev_ioctl(struct file *file,
680 			 unsigned int cmd, unsigned long arg)
681 {
682 	struct joydev_client *client = file->private_data;
683 	struct joydev *joydev = client->joydev;
684 	void __user *argp = (void __user *)arg;
685 	int retval;
686 
687 	retval = mutex_lock_interruptible(&joydev->mutex);
688 	if (retval)
689 		return retval;
690 
691 	if (!joydev->exist) {
692 		retval = -ENODEV;
693 		goto out;
694 	}
695 
696 	switch (cmd) {
697 
698 	case JS_SET_TIMELIMIT:
699 		retval = get_user(joydev->glue.JS_TIMELIMIT,
700 				  (long __user *) arg);
701 		break;
702 
703 	case JS_GET_TIMELIMIT:
704 		retval = put_user(joydev->glue.JS_TIMELIMIT,
705 				  (long __user *) arg);
706 		break;
707 
708 	case JS_SET_ALL:
709 		retval = copy_from_user(&joydev->glue, argp,
710 					sizeof(joydev->glue)) ? -EFAULT: 0;
711 		break;
712 
713 	case JS_GET_ALL:
714 		retval = copy_to_user(argp, &joydev->glue,
715 				      sizeof(joydev->glue)) ? -EFAULT : 0;
716 		break;
717 
718 	default:
719 		retval = joydev_ioctl_common(joydev, cmd, argp);
720 		break;
721 	}
722  out:
723 	mutex_unlock(&joydev->mutex);
724 	return retval;
725 }
726 
727 static const struct file_operations joydev_fops = {
728 	.owner		= THIS_MODULE,
729 	.read		= joydev_read,
730 	.poll		= joydev_poll,
731 	.open		= joydev_open,
732 	.release	= joydev_release,
733 	.unlocked_ioctl	= joydev_ioctl,
734 #ifdef CONFIG_COMPAT
735 	.compat_ioctl	= joydev_compat_ioctl,
736 #endif
737 	.fasync		= joydev_fasync,
738 };
739 
740 static int joydev_install_chrdev(struct joydev *joydev)
741 {
742 	joydev_table[joydev->minor] = joydev;
743 	return 0;
744 }
745 
746 static void joydev_remove_chrdev(struct joydev *joydev)
747 {
748 	mutex_lock(&joydev_table_mutex);
749 	joydev_table[joydev->minor] = NULL;
750 	mutex_unlock(&joydev_table_mutex);
751 }
752 
753 /*
754  * Mark device non-existant. This disables writes, ioctls and
755  * prevents new users from opening the device. Already posted
756  * blocking reads will stay, however new ones will fail.
757  */
758 static void joydev_mark_dead(struct joydev *joydev)
759 {
760 	mutex_lock(&joydev->mutex);
761 	joydev->exist = 0;
762 	mutex_unlock(&joydev->mutex);
763 }
764 
765 static void joydev_cleanup(struct joydev *joydev)
766 {
767 	struct input_handle *handle = &joydev->handle;
768 
769 	joydev_mark_dead(joydev);
770 	joydev_hangup(joydev);
771 	joydev_remove_chrdev(joydev);
772 
773 	/* joydev is marked dead so noone else accesses joydev->open */
774 	if (joydev->open)
775 		input_close_device(handle);
776 }
777 
778 static int joydev_connect(struct input_handler *handler, struct input_dev *dev,
779 			  const struct input_device_id *id)
780 {
781 	struct joydev *joydev;
782 	int i, j, t, minor;
783 	int error;
784 
785 	for (minor = 0; minor < JOYDEV_MINORS; minor++)
786 		if (!joydev_table[minor])
787 			break;
788 
789 	if (minor == JOYDEV_MINORS) {
790 		printk(KERN_ERR "joydev: no more free joydev devices\n");
791 		return -ENFILE;
792 	}
793 
794 	joydev = kzalloc(sizeof(struct joydev), GFP_KERNEL);
795 	if (!joydev)
796 		return -ENOMEM;
797 
798 	INIT_LIST_HEAD(&joydev->client_list);
799 	spin_lock_init(&joydev->client_lock);
800 	mutex_init(&joydev->mutex);
801 	init_waitqueue_head(&joydev->wait);
802 
803 	dev_set_name(&joydev->dev, "js%d", minor);
804 	joydev->exist = 1;
805 	joydev->minor = minor;
806 
807 	joydev->exist = 1;
808 	joydev->handle.dev = input_get_device(dev);
809 	joydev->handle.name = dev_name(&joydev->dev);
810 	joydev->handle.handler = handler;
811 	joydev->handle.private = joydev;
812 
813 	for (i = 0; i < ABS_MAX + 1; i++)
814 		if (test_bit(i, dev->absbit)) {
815 			joydev->absmap[i] = joydev->nabs;
816 			joydev->abspam[joydev->nabs] = i;
817 			joydev->nabs++;
818 		}
819 
820 	for (i = BTN_JOYSTICK - BTN_MISC; i < KEY_MAX - BTN_MISC + 1; i++)
821 		if (test_bit(i + BTN_MISC, dev->keybit)) {
822 			joydev->keymap[i] = joydev->nkey;
823 			joydev->keypam[joydev->nkey] = i + BTN_MISC;
824 			joydev->nkey++;
825 		}
826 
827 	for (i = 0; i < BTN_JOYSTICK - BTN_MISC; i++)
828 		if (test_bit(i + BTN_MISC, dev->keybit)) {
829 			joydev->keymap[i] = joydev->nkey;
830 			joydev->keypam[joydev->nkey] = i + BTN_MISC;
831 			joydev->nkey++;
832 		}
833 
834 	for (i = 0; i < joydev->nabs; i++) {
835 		j = joydev->abspam[i];
836 		if (dev->absmax[j] == dev->absmin[j]) {
837 			joydev->corr[i].type = JS_CORR_NONE;
838 			joydev->abs[i] = dev->abs[j];
839 			continue;
840 		}
841 		joydev->corr[i].type = JS_CORR_BROKEN;
842 		joydev->corr[i].prec = dev->absfuzz[j];
843 		joydev->corr[i].coef[0] =
844 			(dev->absmax[j] + dev->absmin[j]) / 2 - dev->absflat[j];
845 		joydev->corr[i].coef[1] =
846 			(dev->absmax[j] + dev->absmin[j]) / 2 + dev->absflat[j];
847 
848 		t = (dev->absmax[j] - dev->absmin[j]) / 2 - 2 * dev->absflat[j];
849 		if (t) {
850 			joydev->corr[i].coef[2] = (1 << 29) / t;
851 			joydev->corr[i].coef[3] = (1 << 29) / t;
852 
853 			joydev->abs[i] = joydev_correct(dev->abs[j],
854 							joydev->corr + i);
855 		}
856 	}
857 
858 	joydev->dev.devt = MKDEV(INPUT_MAJOR, JOYDEV_MINOR_BASE + minor);
859 	joydev->dev.class = &input_class;
860 	joydev->dev.parent = &dev->dev;
861 	joydev->dev.release = joydev_free;
862 	device_initialize(&joydev->dev);
863 
864 	error = input_register_handle(&joydev->handle);
865 	if (error)
866 		goto err_free_joydev;
867 
868 	error = joydev_install_chrdev(joydev);
869 	if (error)
870 		goto err_unregister_handle;
871 
872 	error = device_add(&joydev->dev);
873 	if (error)
874 		goto err_cleanup_joydev;
875 
876 	return 0;
877 
878  err_cleanup_joydev:
879 	joydev_cleanup(joydev);
880  err_unregister_handle:
881 	input_unregister_handle(&joydev->handle);
882  err_free_joydev:
883 	put_device(&joydev->dev);
884 	return error;
885 }
886 
887 static void joydev_disconnect(struct input_handle *handle)
888 {
889 	struct joydev *joydev = handle->private;
890 
891 	device_del(&joydev->dev);
892 	joydev_cleanup(joydev);
893 	input_unregister_handle(handle);
894 	put_device(&joydev->dev);
895 }
896 
897 static const struct input_device_id joydev_blacklist[] = {
898 	{
899 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
900 				INPUT_DEVICE_ID_MATCH_KEYBIT,
901 		.evbit = { BIT_MASK(EV_KEY) },
902 		.keybit = { [BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH) },
903 	},	/* Avoid itouchpads and touchscreens */
904 	{
905 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
906 				INPUT_DEVICE_ID_MATCH_KEYBIT,
907 		.evbit = { BIT_MASK(EV_KEY) },
908 		.keybit = { [BIT_WORD(BTN_DIGI)] = BIT_MASK(BTN_DIGI) },
909 	},	/* Avoid tablets, digitisers and similar devices */
910 	{ }	/* Terminating entry */
911 };
912 
913 static const struct input_device_id joydev_ids[] = {
914 	{
915 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
916 				INPUT_DEVICE_ID_MATCH_ABSBIT,
917 		.evbit = { BIT_MASK(EV_ABS) },
918 		.absbit = { BIT_MASK(ABS_X) },
919 	},
920 	{
921 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
922 				INPUT_DEVICE_ID_MATCH_ABSBIT,
923 		.evbit = { BIT_MASK(EV_ABS) },
924 		.absbit = { BIT_MASK(ABS_WHEEL) },
925 	},
926 	{
927 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
928 				INPUT_DEVICE_ID_MATCH_ABSBIT,
929 		.evbit = { BIT_MASK(EV_ABS) },
930 		.absbit = { BIT_MASK(ABS_THROTTLE) },
931 	},
932 	{ }	/* Terminating entry */
933 };
934 
935 MODULE_DEVICE_TABLE(input, joydev_ids);
936 
937 static struct input_handler joydev_handler = {
938 	.event		= joydev_event,
939 	.connect	= joydev_connect,
940 	.disconnect	= joydev_disconnect,
941 	.fops		= &joydev_fops,
942 	.minor		= JOYDEV_MINOR_BASE,
943 	.name		= "joydev",
944 	.id_table	= joydev_ids,
945 	.blacklist	= joydev_blacklist,
946 };
947 
948 static int __init joydev_init(void)
949 {
950 	return input_register_handler(&joydev_handler);
951 }
952 
953 static void __exit joydev_exit(void)
954 {
955 	input_unregister_handler(&joydev_handler);
956 }
957 
958 module_init(joydev_init);
959 module_exit(joydev_exit);
960