xref: /openbmc/linux/drivers/input/joydev.c (revision 81d67439)
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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14 
15 #include <asm/io.h>
16 #include <asm/system.h>
17 #include <linux/delay.h>
18 #include <linux/errno.h>
19 #include <linux/joystick.h>
20 #include <linux/input.h>
21 #include <linux/kernel.h>
22 #include <linux/major.h>
23 #include <linux/sched.h>
24 #include <linux/slab.h>
25 #include <linux/mm.h>
26 #include <linux/miscdevice.h>
27 #include <linux/module.h>
28 #include <linux/poll.h>
29 #include <linux/init.h>
30 #include <linux/device.h>
31 
32 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
33 MODULE_DESCRIPTION("Joystick device interfaces");
34 MODULE_SUPPORTED_DEVICE("input/js");
35 MODULE_LICENSE("GPL");
36 
37 #define JOYDEV_MINOR_BASE	0
38 #define JOYDEV_MINORS		16
39 #define JOYDEV_BUFFER_SIZE	64
40 
41 struct joydev {
42 	int open;
43 	int minor;
44 	struct input_handle handle;
45 	wait_queue_head_t wait;
46 	struct list_head client_list;
47 	spinlock_t client_lock; /* protects client_list */
48 	struct mutex mutex;
49 	struct device dev;
50 	bool exist;
51 
52 	struct js_corr corr[ABS_CNT];
53 	struct JS_DATA_SAVE_TYPE glue;
54 	int nabs;
55 	int nkey;
56 	__u16 keymap[KEY_MAX - BTN_MISC + 1];
57 	__u16 keypam[KEY_MAX - BTN_MISC + 1];
58 	__u8 absmap[ABS_CNT];
59 	__u8 abspam[ABS_CNT];
60 	__s16 abs[ABS_CNT];
61 };
62 
63 struct joydev_client {
64 	struct js_event buffer[JOYDEV_BUFFER_SIZE];
65 	int head;
66 	int tail;
67 	int startup;
68 	spinlock_t buffer_lock; /* protects access to buffer, head and tail */
69 	struct fasync_struct *fasync;
70 	struct joydev *joydev;
71 	struct list_head node;
72 };
73 
74 static struct joydev *joydev_table[JOYDEV_MINORS];
75 static DEFINE_MUTEX(joydev_table_mutex);
76 
77 static int joydev_correct(int value, struct js_corr *corr)
78 {
79 	switch (corr->type) {
80 
81 	case JS_CORR_NONE:
82 		break;
83 
84 	case JS_CORR_BROKEN:
85 		value = value > corr->coef[0] ? (value < corr->coef[1] ? 0 :
86 			((corr->coef[3] * (value - corr->coef[1])) >> 14)) :
87 			((corr->coef[2] * (value - corr->coef[0])) >> 14);
88 		break;
89 
90 	default:
91 		return 0;
92 	}
93 
94 	return value < -32767 ? -32767 : (value > 32767 ? 32767 : value);
95 }
96 
97 static void joydev_pass_event(struct joydev_client *client,
98 			      struct js_event *event)
99 {
100 	struct joydev *joydev = client->joydev;
101 
102 	/*
103 	 * IRQs already disabled, just acquire the lock
104 	 */
105 	spin_lock(&client->buffer_lock);
106 
107 	client->buffer[client->head] = *event;
108 
109 	if (client->startup == joydev->nabs + joydev->nkey) {
110 		client->head++;
111 		client->head &= JOYDEV_BUFFER_SIZE - 1;
112 		if (client->tail == client->head)
113 			client->startup = 0;
114 	}
115 
116 	spin_unlock(&client->buffer_lock);
117 
118 	kill_fasync(&client->fasync, SIGIO, POLL_IN);
119 }
120 
121 static void joydev_event(struct input_handle *handle,
122 			 unsigned int type, unsigned int code, int value)
123 {
124 	struct joydev *joydev = handle->private;
125 	struct joydev_client *client;
126 	struct js_event event;
127 
128 	switch (type) {
129 
130 	case EV_KEY:
131 		if (code < BTN_MISC || value == 2)
132 			return;
133 		event.type = JS_EVENT_BUTTON;
134 		event.number = joydev->keymap[code - BTN_MISC];
135 		event.value = value;
136 		break;
137 
138 	case EV_ABS:
139 		event.type = JS_EVENT_AXIS;
140 		event.number = joydev->absmap[code];
141 		event.value = joydev_correct(value,
142 					&joydev->corr[event.number]);
143 		if (event.value == joydev->abs[event.number])
144 			return;
145 		joydev->abs[event.number] = event.value;
146 		break;
147 
148 	default:
149 		return;
150 	}
151 
152 	event.time = jiffies_to_msecs(jiffies);
153 
154 	rcu_read_lock();
155 	list_for_each_entry_rcu(client, &joydev->client_list, node)
156 		joydev_pass_event(client, &event);
157 	rcu_read_unlock();
158 
159 	wake_up_interruptible(&joydev->wait);
160 }
161 
162 static int joydev_fasync(int fd, struct file *file, int on)
163 {
164 	struct joydev_client *client = file->private_data;
165 
166 	return fasync_helper(fd, file, on, &client->fasync);
167 }
168 
169 static void joydev_free(struct device *dev)
170 {
171 	struct joydev *joydev = container_of(dev, struct joydev, dev);
172 
173 	input_put_device(joydev->handle.dev);
174 	kfree(joydev);
175 }
176 
177 static void joydev_attach_client(struct joydev *joydev,
178 				 struct joydev_client *client)
179 {
180 	spin_lock(&joydev->client_lock);
181 	list_add_tail_rcu(&client->node, &joydev->client_list);
182 	spin_unlock(&joydev->client_lock);
183 }
184 
185 static void joydev_detach_client(struct joydev *joydev,
186 				 struct joydev_client *client)
187 {
188 	spin_lock(&joydev->client_lock);
189 	list_del_rcu(&client->node);
190 	spin_unlock(&joydev->client_lock);
191 	synchronize_rcu();
192 }
193 
194 static int joydev_open_device(struct joydev *joydev)
195 {
196 	int retval;
197 
198 	retval = mutex_lock_interruptible(&joydev->mutex);
199 	if (retval)
200 		return retval;
201 
202 	if (!joydev->exist)
203 		retval = -ENODEV;
204 	else if (!joydev->open++) {
205 		retval = input_open_device(&joydev->handle);
206 		if (retval)
207 			joydev->open--;
208 	}
209 
210 	mutex_unlock(&joydev->mutex);
211 	return retval;
212 }
213 
214 static void joydev_close_device(struct joydev *joydev)
215 {
216 	mutex_lock(&joydev->mutex);
217 
218 	if (joydev->exist && !--joydev->open)
219 		input_close_device(&joydev->handle);
220 
221 	mutex_unlock(&joydev->mutex);
222 }
223 
224 /*
225  * Wake up users waiting for IO so they can disconnect from
226  * dead device.
227  */
228 static void joydev_hangup(struct joydev *joydev)
229 {
230 	struct joydev_client *client;
231 
232 	spin_lock(&joydev->client_lock);
233 	list_for_each_entry(client, &joydev->client_list, node)
234 		kill_fasync(&client->fasync, SIGIO, POLL_HUP);
235 	spin_unlock(&joydev->client_lock);
236 
237 	wake_up_interruptible(&joydev->wait);
238 }
239 
240 static int joydev_release(struct inode *inode, struct file *file)
241 {
242 	struct joydev_client *client = file->private_data;
243 	struct joydev *joydev = client->joydev;
244 
245 	joydev_detach_client(joydev, client);
246 	kfree(client);
247 
248 	joydev_close_device(joydev);
249 	put_device(&joydev->dev);
250 
251 	return 0;
252 }
253 
254 static int joydev_open(struct inode *inode, struct file *file)
255 {
256 	struct joydev_client *client;
257 	struct joydev *joydev;
258 	int i = iminor(inode) - JOYDEV_MINOR_BASE;
259 	int error;
260 
261 	if (i >= JOYDEV_MINORS)
262 		return -ENODEV;
263 
264 	error = mutex_lock_interruptible(&joydev_table_mutex);
265 	if (error)
266 		return error;
267 	joydev = joydev_table[i];
268 	if (joydev)
269 		get_device(&joydev->dev);
270 	mutex_unlock(&joydev_table_mutex);
271 
272 	if (!joydev)
273 		return -ENODEV;
274 
275 	client = kzalloc(sizeof(struct joydev_client), GFP_KERNEL);
276 	if (!client) {
277 		error = -ENOMEM;
278 		goto err_put_joydev;
279 	}
280 
281 	spin_lock_init(&client->buffer_lock);
282 	client->joydev = joydev;
283 	joydev_attach_client(joydev, client);
284 
285 	error = joydev_open_device(joydev);
286 	if (error)
287 		goto err_free_client;
288 
289 	file->private_data = client;
290 	nonseekable_open(inode, file);
291 
292 	return 0;
293 
294  err_free_client:
295 	joydev_detach_client(joydev, client);
296 	kfree(client);
297  err_put_joydev:
298 	put_device(&joydev->dev);
299 	return error;
300 }
301 
302 static int joydev_generate_startup_event(struct joydev_client *client,
303 					 struct input_dev *input,
304 					 struct js_event *event)
305 {
306 	struct joydev *joydev = client->joydev;
307 	int have_event;
308 
309 	spin_lock_irq(&client->buffer_lock);
310 
311 	have_event = client->startup < joydev->nabs + joydev->nkey;
312 
313 	if (have_event) {
314 
315 		event->time = jiffies_to_msecs(jiffies);
316 		if (client->startup < joydev->nkey) {
317 			event->type = JS_EVENT_BUTTON | JS_EVENT_INIT;
318 			event->number = client->startup;
319 			event->value = !!test_bit(joydev->keypam[event->number],
320 						  input->key);
321 		} else {
322 			event->type = JS_EVENT_AXIS | JS_EVENT_INIT;
323 			event->number = client->startup - joydev->nkey;
324 			event->value = joydev->abs[event->number];
325 		}
326 		client->startup++;
327 	}
328 
329 	spin_unlock_irq(&client->buffer_lock);
330 
331 	return have_event;
332 }
333 
334 static int joydev_fetch_next_event(struct joydev_client *client,
335 				   struct js_event *event)
336 {
337 	int have_event;
338 
339 	spin_lock_irq(&client->buffer_lock);
340 
341 	have_event = client->head != client->tail;
342 	if (have_event) {
343 		*event = client->buffer[client->tail++];
344 		client->tail &= JOYDEV_BUFFER_SIZE - 1;
345 	}
346 
347 	spin_unlock_irq(&client->buffer_lock);
348 
349 	return have_event;
350 }
351 
352 /*
353  * Old joystick interface
354  */
355 static ssize_t joydev_0x_read(struct joydev_client *client,
356 			      struct input_dev *input,
357 			      char __user *buf)
358 {
359 	struct joydev *joydev = client->joydev;
360 	struct JS_DATA_TYPE data;
361 	int i;
362 
363 	spin_lock_irq(&input->event_lock);
364 
365 	/*
366 	 * Get device state
367 	 */
368 	for (data.buttons = i = 0; i < 32 && i < joydev->nkey; i++)
369 		data.buttons |=
370 			test_bit(joydev->keypam[i], input->key) ? (1 << i) : 0;
371 	data.x = (joydev->abs[0] / 256 + 128) >> joydev->glue.JS_CORR.x;
372 	data.y = (joydev->abs[1] / 256 + 128) >> joydev->glue.JS_CORR.y;
373 
374 	/*
375 	 * Reset reader's event queue
376 	 */
377 	spin_lock(&client->buffer_lock);
378 	client->startup = 0;
379 	client->tail = client->head;
380 	spin_unlock(&client->buffer_lock);
381 
382 	spin_unlock_irq(&input->event_lock);
383 
384 	if (copy_to_user(buf, &data, sizeof(struct JS_DATA_TYPE)))
385 		return -EFAULT;
386 
387 	return sizeof(struct JS_DATA_TYPE);
388 }
389 
390 static inline int joydev_data_pending(struct joydev_client *client)
391 {
392 	struct joydev *joydev = client->joydev;
393 
394 	return client->startup < joydev->nabs + joydev->nkey ||
395 		client->head != client->tail;
396 }
397 
398 static ssize_t joydev_read(struct file *file, char __user *buf,
399 			   size_t count, loff_t *ppos)
400 {
401 	struct joydev_client *client = file->private_data;
402 	struct joydev *joydev = client->joydev;
403 	struct input_dev *input = joydev->handle.dev;
404 	struct js_event event;
405 	int retval;
406 
407 	if (!joydev->exist)
408 		return -ENODEV;
409 
410 	if (count < sizeof(struct js_event))
411 		return -EINVAL;
412 
413 	if (count == sizeof(struct JS_DATA_TYPE))
414 		return joydev_0x_read(client, input, buf);
415 
416 	if (!joydev_data_pending(client) && (file->f_flags & O_NONBLOCK))
417 		return -EAGAIN;
418 
419 	retval = wait_event_interruptible(joydev->wait,
420 			!joydev->exist || joydev_data_pending(client));
421 	if (retval)
422 		return retval;
423 
424 	if (!joydev->exist)
425 		return -ENODEV;
426 
427 	while (retval + sizeof(struct js_event) <= count &&
428 	       joydev_generate_startup_event(client, input, &event)) {
429 
430 		if (copy_to_user(buf + retval, &event, sizeof(struct js_event)))
431 			return -EFAULT;
432 
433 		retval += sizeof(struct js_event);
434 	}
435 
436 	while (retval + sizeof(struct js_event) <= count &&
437 	       joydev_fetch_next_event(client, &event)) {
438 
439 		if (copy_to_user(buf + retval, &event, sizeof(struct js_event)))
440 			return -EFAULT;
441 
442 		retval += sizeof(struct js_event);
443 	}
444 
445 	return retval;
446 }
447 
448 /* No kernel lock - fine */
449 static unsigned int joydev_poll(struct file *file, poll_table *wait)
450 {
451 	struct joydev_client *client = file->private_data;
452 	struct joydev *joydev = client->joydev;
453 
454 	poll_wait(file, &joydev->wait, wait);
455 	return (joydev_data_pending(client) ? (POLLIN | POLLRDNORM) : 0) |
456 		(joydev->exist ?  0 : (POLLHUP | POLLERR));
457 }
458 
459 static int joydev_handle_JSIOCSAXMAP(struct joydev *joydev,
460 				     void __user *argp, size_t len)
461 {
462 	__u8 *abspam;
463 	int i;
464 	int retval = 0;
465 
466 	len = min(len, sizeof(joydev->abspam));
467 
468 	/* Validate the map. */
469 	abspam = kmalloc(len, GFP_KERNEL);
470 	if (!abspam)
471 		return -ENOMEM;
472 
473 	if (copy_from_user(abspam, argp, len)) {
474 		retval = -EFAULT;
475 		goto out;
476 	}
477 
478 	for (i = 0; i < joydev->nabs; i++) {
479 		if (abspam[i] > ABS_MAX) {
480 			retval = -EINVAL;
481 			goto out;
482 		}
483 	}
484 
485 	memcpy(joydev->abspam, abspam, len);
486 
487 	for (i = 0; i < joydev->nabs; i++)
488 		joydev->absmap[joydev->abspam[i]] = i;
489 
490  out:
491 	kfree(abspam);
492 	return retval;
493 }
494 
495 static int joydev_handle_JSIOCSBTNMAP(struct joydev *joydev,
496 				      void __user *argp, size_t len)
497 {
498 	__u16 *keypam;
499 	int i;
500 	int retval = 0;
501 
502 	len = min(len, sizeof(joydev->keypam));
503 
504 	/* Validate the map. */
505 	keypam = kmalloc(len, GFP_KERNEL);
506 	if (!keypam)
507 		return -ENOMEM;
508 
509 	if (copy_from_user(keypam, argp, len)) {
510 		retval = -EFAULT;
511 		goto out;
512 	}
513 
514 	for (i = 0; i < joydev->nkey; i++) {
515 		if (keypam[i] > KEY_MAX || keypam[i] < BTN_MISC) {
516 			retval = -EINVAL;
517 			goto out;
518 		}
519 	}
520 
521 	memcpy(joydev->keypam, keypam, len);
522 
523 	for (i = 0; i < joydev->nkey; i++)
524 		joydev->keymap[keypam[i] - BTN_MISC] = i;
525 
526  out:
527 	kfree(keypam);
528 	return retval;
529 }
530 
531 
532 static int joydev_ioctl_common(struct joydev *joydev,
533 				unsigned int cmd, void __user *argp)
534 {
535 	struct input_dev *dev = joydev->handle.dev;
536 	size_t len;
537 	int i;
538 	const char *name;
539 
540 	/* Process fixed-sized commands. */
541 	switch (cmd) {
542 
543 	case JS_SET_CAL:
544 		return copy_from_user(&joydev->glue.JS_CORR, argp,
545 				sizeof(joydev->glue.JS_CORR)) ? -EFAULT : 0;
546 
547 	case JS_GET_CAL:
548 		return copy_to_user(argp, &joydev->glue.JS_CORR,
549 				sizeof(joydev->glue.JS_CORR)) ? -EFAULT : 0;
550 
551 	case JS_SET_TIMEOUT:
552 		return get_user(joydev->glue.JS_TIMEOUT, (s32 __user *) argp);
553 
554 	case JS_GET_TIMEOUT:
555 		return put_user(joydev->glue.JS_TIMEOUT, (s32 __user *) argp);
556 
557 	case JSIOCGVERSION:
558 		return put_user(JS_VERSION, (__u32 __user *) argp);
559 
560 	case JSIOCGAXES:
561 		return put_user(joydev->nabs, (__u8 __user *) argp);
562 
563 	case JSIOCGBUTTONS:
564 		return put_user(joydev->nkey, (__u8 __user *) argp);
565 
566 	case JSIOCSCORR:
567 		if (copy_from_user(joydev->corr, argp,
568 			      sizeof(joydev->corr[0]) * joydev->nabs))
569 			return -EFAULT;
570 
571 		for (i = 0; i < joydev->nabs; i++) {
572 			int val = input_abs_get_val(dev, joydev->abspam[i]);
573 			joydev->abs[i] = joydev_correct(val, &joydev->corr[i]);
574 		}
575 		return 0;
576 
577 	case JSIOCGCORR:
578 		return copy_to_user(argp, joydev->corr,
579 			sizeof(joydev->corr[0]) * joydev->nabs) ? -EFAULT : 0;
580 
581 	}
582 
583 	/*
584 	 * Process variable-sized commands (the axis and button map commands
585 	 * are considered variable-sized to decouple them from the values of
586 	 * ABS_MAX and KEY_MAX).
587 	 */
588 	switch (cmd & ~IOCSIZE_MASK) {
589 
590 	case (JSIOCSAXMAP & ~IOCSIZE_MASK):
591 		return joydev_handle_JSIOCSAXMAP(joydev, argp, _IOC_SIZE(cmd));
592 
593 	case (JSIOCGAXMAP & ~IOCSIZE_MASK):
594 		len = min_t(size_t, _IOC_SIZE(cmd), sizeof(joydev->abspam));
595 		return copy_to_user(argp, joydev->abspam, len) ? -EFAULT : len;
596 
597 	case (JSIOCSBTNMAP & ~IOCSIZE_MASK):
598 		return joydev_handle_JSIOCSBTNMAP(joydev, argp, _IOC_SIZE(cmd));
599 
600 	case (JSIOCGBTNMAP & ~IOCSIZE_MASK):
601 		len = min_t(size_t, _IOC_SIZE(cmd), sizeof(joydev->keypam));
602 		return copy_to_user(argp, joydev->keypam, len) ? -EFAULT : len;
603 
604 	case JSIOCGNAME(0):
605 		name = dev->name;
606 		if (!name)
607 			return 0;
608 
609 		len = min_t(size_t, _IOC_SIZE(cmd), strlen(name) + 1);
610 		return copy_to_user(argp, name, len) ? -EFAULT : len;
611 	}
612 
613 	return -EINVAL;
614 }
615 
616 #ifdef CONFIG_COMPAT
617 static long joydev_compat_ioctl(struct file *file,
618 				unsigned int cmd, unsigned long arg)
619 {
620 	struct joydev_client *client = file->private_data;
621 	struct joydev *joydev = client->joydev;
622 	void __user *argp = (void __user *)arg;
623 	s32 tmp32;
624 	struct JS_DATA_SAVE_TYPE_32 ds32;
625 	int retval;
626 
627 	retval = mutex_lock_interruptible(&joydev->mutex);
628 	if (retval)
629 		return retval;
630 
631 	if (!joydev->exist) {
632 		retval = -ENODEV;
633 		goto out;
634 	}
635 
636 	switch (cmd) {
637 
638 	case JS_SET_TIMELIMIT:
639 		retval = get_user(tmp32, (s32 __user *) arg);
640 		if (retval == 0)
641 			joydev->glue.JS_TIMELIMIT = tmp32;
642 		break;
643 
644 	case JS_GET_TIMELIMIT:
645 		tmp32 = joydev->glue.JS_TIMELIMIT;
646 		retval = put_user(tmp32, (s32 __user *) arg);
647 		break;
648 
649 	case JS_SET_ALL:
650 		retval = copy_from_user(&ds32, argp,
651 					sizeof(ds32)) ? -EFAULT : 0;
652 		if (retval == 0) {
653 			joydev->glue.JS_TIMEOUT    = ds32.JS_TIMEOUT;
654 			joydev->glue.BUSY          = ds32.BUSY;
655 			joydev->glue.JS_EXPIRETIME = ds32.JS_EXPIRETIME;
656 			joydev->glue.JS_TIMELIMIT  = ds32.JS_TIMELIMIT;
657 			joydev->glue.JS_SAVE       = ds32.JS_SAVE;
658 			joydev->glue.JS_CORR       = ds32.JS_CORR;
659 		}
660 		break;
661 
662 	case JS_GET_ALL:
663 		ds32.JS_TIMEOUT    = joydev->glue.JS_TIMEOUT;
664 		ds32.BUSY          = joydev->glue.BUSY;
665 		ds32.JS_EXPIRETIME = joydev->glue.JS_EXPIRETIME;
666 		ds32.JS_TIMELIMIT  = joydev->glue.JS_TIMELIMIT;
667 		ds32.JS_SAVE       = joydev->glue.JS_SAVE;
668 		ds32.JS_CORR       = joydev->glue.JS_CORR;
669 
670 		retval = copy_to_user(argp, &ds32, sizeof(ds32)) ? -EFAULT : 0;
671 		break;
672 
673 	default:
674 		retval = joydev_ioctl_common(joydev, cmd, argp);
675 		break;
676 	}
677 
678  out:
679 	mutex_unlock(&joydev->mutex);
680 	return retval;
681 }
682 #endif /* CONFIG_COMPAT */
683 
684 static long joydev_ioctl(struct file *file,
685 			 unsigned int cmd, unsigned long arg)
686 {
687 	struct joydev_client *client = file->private_data;
688 	struct joydev *joydev = client->joydev;
689 	void __user *argp = (void __user *)arg;
690 	int retval;
691 
692 	retval = mutex_lock_interruptible(&joydev->mutex);
693 	if (retval)
694 		return retval;
695 
696 	if (!joydev->exist) {
697 		retval = -ENODEV;
698 		goto out;
699 	}
700 
701 	switch (cmd) {
702 
703 	case JS_SET_TIMELIMIT:
704 		retval = get_user(joydev->glue.JS_TIMELIMIT,
705 				  (long __user *) arg);
706 		break;
707 
708 	case JS_GET_TIMELIMIT:
709 		retval = put_user(joydev->glue.JS_TIMELIMIT,
710 				  (long __user *) arg);
711 		break;
712 
713 	case JS_SET_ALL:
714 		retval = copy_from_user(&joydev->glue, argp,
715 					sizeof(joydev->glue)) ? -EFAULT: 0;
716 		break;
717 
718 	case JS_GET_ALL:
719 		retval = copy_to_user(argp, &joydev->glue,
720 				      sizeof(joydev->glue)) ? -EFAULT : 0;
721 		break;
722 
723 	default:
724 		retval = joydev_ioctl_common(joydev, cmd, argp);
725 		break;
726 	}
727  out:
728 	mutex_unlock(&joydev->mutex);
729 	return retval;
730 }
731 
732 static const struct file_operations joydev_fops = {
733 	.owner		= THIS_MODULE,
734 	.read		= joydev_read,
735 	.poll		= joydev_poll,
736 	.open		= joydev_open,
737 	.release	= joydev_release,
738 	.unlocked_ioctl	= joydev_ioctl,
739 #ifdef CONFIG_COMPAT
740 	.compat_ioctl	= joydev_compat_ioctl,
741 #endif
742 	.fasync		= joydev_fasync,
743 	.llseek		= no_llseek,
744 };
745 
746 static int joydev_install_chrdev(struct joydev *joydev)
747 {
748 	joydev_table[joydev->minor] = joydev;
749 	return 0;
750 }
751 
752 static void joydev_remove_chrdev(struct joydev *joydev)
753 {
754 	mutex_lock(&joydev_table_mutex);
755 	joydev_table[joydev->minor] = NULL;
756 	mutex_unlock(&joydev_table_mutex);
757 }
758 
759 /*
760  * Mark device non-existent. This disables writes, ioctls and
761  * prevents new users from opening the device. Already posted
762  * blocking reads will stay, however new ones will fail.
763  */
764 static void joydev_mark_dead(struct joydev *joydev)
765 {
766 	mutex_lock(&joydev->mutex);
767 	joydev->exist = false;
768 	mutex_unlock(&joydev->mutex);
769 }
770 
771 static void joydev_cleanup(struct joydev *joydev)
772 {
773 	struct input_handle *handle = &joydev->handle;
774 
775 	joydev_mark_dead(joydev);
776 	joydev_hangup(joydev);
777 	joydev_remove_chrdev(joydev);
778 
779 	/* joydev is marked dead so no one else accesses joydev->open */
780 	if (joydev->open)
781 		input_close_device(handle);
782 }
783 
784 
785 static bool joydev_match(struct input_handler *handler, struct input_dev *dev)
786 {
787 	/* Avoid touchpads and touchscreens */
788 	if (test_bit(EV_KEY, dev->evbit) && test_bit(BTN_TOUCH, dev->keybit))
789 		return false;
790 
791 	/* Avoid tablets, digitisers and similar devices */
792 	if (test_bit(EV_KEY, dev->evbit) && test_bit(BTN_DIGI, dev->keybit))
793 		return false;
794 
795 	return true;
796 }
797 
798 static int joydev_connect(struct input_handler *handler, struct input_dev *dev,
799 			  const struct input_device_id *id)
800 {
801 	struct joydev *joydev;
802 	int i, j, t, minor;
803 	int error;
804 
805 	for (minor = 0; minor < JOYDEV_MINORS; minor++)
806 		if (!joydev_table[minor])
807 			break;
808 
809 	if (minor == JOYDEV_MINORS) {
810 		pr_err("no more free joydev devices\n");
811 		return -ENFILE;
812 	}
813 
814 	joydev = kzalloc(sizeof(struct joydev), GFP_KERNEL);
815 	if (!joydev)
816 		return -ENOMEM;
817 
818 	INIT_LIST_HEAD(&joydev->client_list);
819 	spin_lock_init(&joydev->client_lock);
820 	mutex_init(&joydev->mutex);
821 	init_waitqueue_head(&joydev->wait);
822 
823 	dev_set_name(&joydev->dev, "js%d", minor);
824 	joydev->exist = true;
825 	joydev->minor = minor;
826 
827 	joydev->handle.dev = input_get_device(dev);
828 	joydev->handle.name = dev_name(&joydev->dev);
829 	joydev->handle.handler = handler;
830 	joydev->handle.private = joydev;
831 
832 	for (i = 0; i < ABS_CNT; i++)
833 		if (test_bit(i, dev->absbit)) {
834 			joydev->absmap[i] = joydev->nabs;
835 			joydev->abspam[joydev->nabs] = i;
836 			joydev->nabs++;
837 		}
838 
839 	for (i = BTN_JOYSTICK - BTN_MISC; i < KEY_MAX - BTN_MISC + 1; i++)
840 		if (test_bit(i + BTN_MISC, dev->keybit)) {
841 			joydev->keymap[i] = joydev->nkey;
842 			joydev->keypam[joydev->nkey] = i + BTN_MISC;
843 			joydev->nkey++;
844 		}
845 
846 	for (i = 0; i < BTN_JOYSTICK - BTN_MISC; i++)
847 		if (test_bit(i + BTN_MISC, dev->keybit)) {
848 			joydev->keymap[i] = joydev->nkey;
849 			joydev->keypam[joydev->nkey] = i + BTN_MISC;
850 			joydev->nkey++;
851 		}
852 
853 	for (i = 0; i < joydev->nabs; i++) {
854 		j = joydev->abspam[i];
855 		if (input_abs_get_max(dev, j) == input_abs_get_min(dev, j)) {
856 			joydev->corr[i].type = JS_CORR_NONE;
857 			joydev->abs[i] = input_abs_get_val(dev, j);
858 			continue;
859 		}
860 		joydev->corr[i].type = JS_CORR_BROKEN;
861 		joydev->corr[i].prec = input_abs_get_fuzz(dev, j);
862 
863 		t = (input_abs_get_max(dev, j) + input_abs_get_min(dev, j)) / 2;
864 		joydev->corr[i].coef[0] = t - input_abs_get_flat(dev, j);
865 		joydev->corr[i].coef[1] = t + input_abs_get_flat(dev, j);
866 
867 		t = (input_abs_get_max(dev, j) - input_abs_get_min(dev, j)) / 2
868 			- 2 * input_abs_get_flat(dev, j);
869 		if (t) {
870 			joydev->corr[i].coef[2] = (1 << 29) / t;
871 			joydev->corr[i].coef[3] = (1 << 29) / t;
872 
873 			joydev->abs[i] =
874 				joydev_correct(input_abs_get_val(dev, j),
875 					       joydev->corr + i);
876 		}
877 	}
878 
879 	joydev->dev.devt = MKDEV(INPUT_MAJOR, JOYDEV_MINOR_BASE + minor);
880 	joydev->dev.class = &input_class;
881 	joydev->dev.parent = &dev->dev;
882 	joydev->dev.release = joydev_free;
883 	device_initialize(&joydev->dev);
884 
885 	error = input_register_handle(&joydev->handle);
886 	if (error)
887 		goto err_free_joydev;
888 
889 	error = joydev_install_chrdev(joydev);
890 	if (error)
891 		goto err_unregister_handle;
892 
893 	error = device_add(&joydev->dev);
894 	if (error)
895 		goto err_cleanup_joydev;
896 
897 	return 0;
898 
899  err_cleanup_joydev:
900 	joydev_cleanup(joydev);
901  err_unregister_handle:
902 	input_unregister_handle(&joydev->handle);
903  err_free_joydev:
904 	put_device(&joydev->dev);
905 	return error;
906 }
907 
908 static void joydev_disconnect(struct input_handle *handle)
909 {
910 	struct joydev *joydev = handle->private;
911 
912 	device_del(&joydev->dev);
913 	joydev_cleanup(joydev);
914 	input_unregister_handle(handle);
915 	put_device(&joydev->dev);
916 }
917 
918 static const struct input_device_id joydev_ids[] = {
919 	{
920 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
921 				INPUT_DEVICE_ID_MATCH_ABSBIT,
922 		.evbit = { BIT_MASK(EV_ABS) },
923 		.absbit = { BIT_MASK(ABS_X) },
924 	},
925 	{
926 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
927 				INPUT_DEVICE_ID_MATCH_ABSBIT,
928 		.evbit = { BIT_MASK(EV_ABS) },
929 		.absbit = { BIT_MASK(ABS_WHEEL) },
930 	},
931 	{
932 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
933 				INPUT_DEVICE_ID_MATCH_ABSBIT,
934 		.evbit = { BIT_MASK(EV_ABS) },
935 		.absbit = { BIT_MASK(ABS_THROTTLE) },
936 	},
937 	{
938 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
939 				INPUT_DEVICE_ID_MATCH_KEYBIT,
940 		.evbit = { BIT_MASK(EV_KEY) },
941 		.keybit = {[BIT_WORD(BTN_JOYSTICK)] = BIT_MASK(BTN_JOYSTICK) },
942 	},
943 	{
944 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
945 				INPUT_DEVICE_ID_MATCH_KEYBIT,
946 		.evbit = { BIT_MASK(EV_KEY) },
947 		.keybit = { [BIT_WORD(BTN_GAMEPAD)] = BIT_MASK(BTN_GAMEPAD) },
948 	},
949 	{
950 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
951 				INPUT_DEVICE_ID_MATCH_KEYBIT,
952 		.evbit = { BIT_MASK(EV_KEY) },
953 		.keybit = { [BIT_WORD(BTN_TRIGGER_HAPPY)] = BIT_MASK(BTN_TRIGGER_HAPPY) },
954 	},
955 	{ }	/* Terminating entry */
956 };
957 
958 MODULE_DEVICE_TABLE(input, joydev_ids);
959 
960 static struct input_handler joydev_handler = {
961 	.event		= joydev_event,
962 	.match		= joydev_match,
963 	.connect	= joydev_connect,
964 	.disconnect	= joydev_disconnect,
965 	.fops		= &joydev_fops,
966 	.minor		= JOYDEV_MINOR_BASE,
967 	.name		= "joydev",
968 	.id_table	= joydev_ids,
969 };
970 
971 static int __init joydev_init(void)
972 {
973 	return input_register_handler(&joydev_handler);
974 }
975 
976 static void __exit joydev_exit(void)
977 {
978 	input_unregister_handler(&joydev_handler);
979 }
980 
981 module_init(joydev_init);
982 module_exit(joydev_exit);
983