xref: /linux/drivers/input/joydev.c (revision 6c363eafc4d637ac4bd83d4a7dd06dd3cfbe7c5f)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Joystick device driver for the input driver suite.
4  *
5  * Copyright (c) 1999-2002 Vojtech Pavlik
6  * Copyright (c) 1999 Colin Van Dyke
7  */
8 
9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10 
11 #include <asm/io.h>
12 #include <linux/delay.h>
13 #include <linux/errno.h>
14 #include <linux/joystick.h>
15 #include <linux/input.h>
16 #include <linux/kernel.h>
17 #include <linux/major.h>
18 #include <linux/sched.h>
19 #include <linux/slab.h>
20 #include <linux/mm.h>
21 #include <linux/module.h>
22 #include <linux/poll.h>
23 #include <linux/init.h>
24 #include <linux/device.h>
25 #include <linux/cdev.h>
26 
27 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
28 MODULE_DESCRIPTION("Joystick device interfaces");
29 MODULE_SUPPORTED_DEVICE("input/js");
30 MODULE_LICENSE("GPL");
31 
32 #define JOYDEV_MINOR_BASE	0
33 #define JOYDEV_MINORS		16
34 #define JOYDEV_BUFFER_SIZE	64
35 
36 struct joydev {
37 	int open;
38 	struct input_handle handle;
39 	wait_queue_head_t wait;
40 	struct list_head client_list;
41 	spinlock_t client_lock; /* protects client_list */
42 	struct mutex mutex;
43 	struct device dev;
44 	struct cdev cdev;
45 	bool exist;
46 
47 	struct js_corr corr[ABS_CNT];
48 	struct JS_DATA_SAVE_TYPE glue;
49 	int nabs;
50 	int nkey;
51 	__u16 keymap[KEY_MAX - BTN_MISC + 1];
52 	__u16 keypam[KEY_MAX - BTN_MISC + 1];
53 	__u8 absmap[ABS_CNT];
54 	__u8 abspam[ABS_CNT];
55 	__s16 abs[ABS_CNT];
56 };
57 
58 struct joydev_client {
59 	struct js_event buffer[JOYDEV_BUFFER_SIZE];
60 	int head;
61 	int tail;
62 	int startup;
63 	spinlock_t buffer_lock; /* protects access to buffer, head and tail */
64 	struct fasync_struct *fasync;
65 	struct joydev *joydev;
66 	struct list_head node;
67 };
68 
69 static int joydev_correct(int value, struct js_corr *corr)
70 {
71 	switch (corr->type) {
72 
73 	case JS_CORR_NONE:
74 		break;
75 
76 	case JS_CORR_BROKEN:
77 		value = value > corr->coef[0] ? (value < corr->coef[1] ? 0 :
78 			((corr->coef[3] * (value - corr->coef[1])) >> 14)) :
79 			((corr->coef[2] * (value - corr->coef[0])) >> 14);
80 		break;
81 
82 	default:
83 		return 0;
84 	}
85 
86 	return clamp(value, -32767, 32767);
87 }
88 
89 static void joydev_pass_event(struct joydev_client *client,
90 			      struct js_event *event)
91 {
92 	struct joydev *joydev = client->joydev;
93 
94 	/*
95 	 * IRQs already disabled, just acquire the lock
96 	 */
97 	spin_lock(&client->buffer_lock);
98 
99 	client->buffer[client->head] = *event;
100 
101 	if (client->startup == joydev->nabs + joydev->nkey) {
102 		client->head++;
103 		client->head &= JOYDEV_BUFFER_SIZE - 1;
104 		if (client->tail == client->head)
105 			client->startup = 0;
106 	}
107 
108 	spin_unlock(&client->buffer_lock);
109 
110 	kill_fasync(&client->fasync, SIGIO, POLL_IN);
111 }
112 
113 static void joydev_event(struct input_handle *handle,
114 			 unsigned int type, unsigned int code, int value)
115 {
116 	struct joydev *joydev = handle->private;
117 	struct joydev_client *client;
118 	struct js_event event;
119 
120 	switch (type) {
121 
122 	case EV_KEY:
123 		if (code < BTN_MISC || value == 2)
124 			return;
125 		event.type = JS_EVENT_BUTTON;
126 		event.number = joydev->keymap[code - BTN_MISC];
127 		event.value = value;
128 		break;
129 
130 	case EV_ABS:
131 		event.type = JS_EVENT_AXIS;
132 		event.number = joydev->absmap[code];
133 		event.value = joydev_correct(value,
134 					&joydev->corr[event.number]);
135 		if (event.value == joydev->abs[event.number])
136 			return;
137 		joydev->abs[event.number] = event.value;
138 		break;
139 
140 	default:
141 		return;
142 	}
143 
144 	event.time = jiffies_to_msecs(jiffies);
145 
146 	rcu_read_lock();
147 	list_for_each_entry_rcu(client, &joydev->client_list, node)
148 		joydev_pass_event(client, &event);
149 	rcu_read_unlock();
150 
151 	wake_up_interruptible(&joydev->wait);
152 }
153 
154 static int joydev_fasync(int fd, struct file *file, int on)
155 {
156 	struct joydev_client *client = file->private_data;
157 
158 	return fasync_helper(fd, file, on, &client->fasync);
159 }
160 
161 static void joydev_free(struct device *dev)
162 {
163 	struct joydev *joydev = container_of(dev, struct joydev, dev);
164 
165 	input_put_device(joydev->handle.dev);
166 	kfree(joydev);
167 }
168 
169 static void joydev_attach_client(struct joydev *joydev,
170 				 struct joydev_client *client)
171 {
172 	spin_lock(&joydev->client_lock);
173 	list_add_tail_rcu(&client->node, &joydev->client_list);
174 	spin_unlock(&joydev->client_lock);
175 }
176 
177 static void joydev_detach_client(struct joydev *joydev,
178 				 struct joydev_client *client)
179 {
180 	spin_lock(&joydev->client_lock);
181 	list_del_rcu(&client->node);
182 	spin_unlock(&joydev->client_lock);
183 	synchronize_rcu();
184 }
185 
186 static void joydev_refresh_state(struct joydev *joydev)
187 {
188 	struct input_dev *dev = joydev->handle.dev;
189 	int i, val;
190 
191 	for (i = 0; i < joydev->nabs; i++) {
192 		val = input_abs_get_val(dev, joydev->abspam[i]);
193 		joydev->abs[i] = joydev_correct(val, &joydev->corr[i]);
194 	}
195 }
196 
197 static int joydev_open_device(struct joydev *joydev)
198 {
199 	int retval;
200 
201 	retval = mutex_lock_interruptible(&joydev->mutex);
202 	if (retval)
203 		return retval;
204 
205 	if (!joydev->exist)
206 		retval = -ENODEV;
207 	else if (!joydev->open++) {
208 		retval = input_open_device(&joydev->handle);
209 		if (retval)
210 			joydev->open--;
211 		else
212 			joydev_refresh_state(joydev);
213 	}
214 
215 	mutex_unlock(&joydev->mutex);
216 	return retval;
217 }
218 
219 static void joydev_close_device(struct joydev *joydev)
220 {
221 	mutex_lock(&joydev->mutex);
222 
223 	if (joydev->exist && !--joydev->open)
224 		input_close_device(&joydev->handle);
225 
226 	mutex_unlock(&joydev->mutex);
227 }
228 
229 /*
230  * Wake up users waiting for IO so they can disconnect from
231  * dead device.
232  */
233 static void joydev_hangup(struct joydev *joydev)
234 {
235 	struct joydev_client *client;
236 
237 	spin_lock(&joydev->client_lock);
238 	list_for_each_entry(client, &joydev->client_list, node)
239 		kill_fasync(&client->fasync, SIGIO, POLL_HUP);
240 	spin_unlock(&joydev->client_lock);
241 
242 	wake_up_interruptible(&joydev->wait);
243 }
244 
245 static int joydev_release(struct inode *inode, struct file *file)
246 {
247 	struct joydev_client *client = file->private_data;
248 	struct joydev *joydev = client->joydev;
249 
250 	joydev_detach_client(joydev, client);
251 	kfree(client);
252 
253 	joydev_close_device(joydev);
254 
255 	return 0;
256 }
257 
258 static int joydev_open(struct inode *inode, struct file *file)
259 {
260 	struct joydev *joydev =
261 			container_of(inode->i_cdev, struct joydev, cdev);
262 	struct joydev_client *client;
263 	int error;
264 
265 	client = kzalloc(sizeof(struct joydev_client), GFP_KERNEL);
266 	if (!client)
267 		return -ENOMEM;
268 
269 	spin_lock_init(&client->buffer_lock);
270 	client->joydev = joydev;
271 	joydev_attach_client(joydev, client);
272 
273 	error = joydev_open_device(joydev);
274 	if (error)
275 		goto err_free_client;
276 
277 	file->private_data = client;
278 	stream_open(inode, file);
279 
280 	return 0;
281 
282  err_free_client:
283 	joydev_detach_client(joydev, client);
284 	kfree(client);
285 	return error;
286 }
287 
288 static int joydev_generate_startup_event(struct joydev_client *client,
289 					 struct input_dev *input,
290 					 struct js_event *event)
291 {
292 	struct joydev *joydev = client->joydev;
293 	int have_event;
294 
295 	spin_lock_irq(&client->buffer_lock);
296 
297 	have_event = client->startup < joydev->nabs + joydev->nkey;
298 
299 	if (have_event) {
300 
301 		event->time = jiffies_to_msecs(jiffies);
302 		if (client->startup < joydev->nkey) {
303 			event->type = JS_EVENT_BUTTON | JS_EVENT_INIT;
304 			event->number = client->startup;
305 			event->value = !!test_bit(joydev->keypam[event->number],
306 						  input->key);
307 		} else {
308 			event->type = JS_EVENT_AXIS | JS_EVENT_INIT;
309 			event->number = client->startup - joydev->nkey;
310 			event->value = joydev->abs[event->number];
311 		}
312 		client->startup++;
313 	}
314 
315 	spin_unlock_irq(&client->buffer_lock);
316 
317 	return have_event;
318 }
319 
320 static int joydev_fetch_next_event(struct joydev_client *client,
321 				   struct js_event *event)
322 {
323 	int have_event;
324 
325 	spin_lock_irq(&client->buffer_lock);
326 
327 	have_event = client->head != client->tail;
328 	if (have_event) {
329 		*event = client->buffer[client->tail++];
330 		client->tail &= JOYDEV_BUFFER_SIZE - 1;
331 	}
332 
333 	spin_unlock_irq(&client->buffer_lock);
334 
335 	return have_event;
336 }
337 
338 /*
339  * Old joystick interface
340  */
341 static ssize_t joydev_0x_read(struct joydev_client *client,
342 			      struct input_dev *input,
343 			      char __user *buf)
344 {
345 	struct joydev *joydev = client->joydev;
346 	struct JS_DATA_TYPE data;
347 	int i;
348 
349 	spin_lock_irq(&input->event_lock);
350 
351 	/*
352 	 * Get device state
353 	 */
354 	for (data.buttons = i = 0; i < 32 && i < joydev->nkey; i++)
355 		data.buttons |=
356 			test_bit(joydev->keypam[i], input->key) ? (1 << i) : 0;
357 	data.x = (joydev->abs[0] / 256 + 128) >> joydev->glue.JS_CORR.x;
358 	data.y = (joydev->abs[1] / 256 + 128) >> joydev->glue.JS_CORR.y;
359 
360 	/*
361 	 * Reset reader's event queue
362 	 */
363 	spin_lock(&client->buffer_lock);
364 	client->startup = 0;
365 	client->tail = client->head;
366 	spin_unlock(&client->buffer_lock);
367 
368 	spin_unlock_irq(&input->event_lock);
369 
370 	if (copy_to_user(buf, &data, sizeof(struct JS_DATA_TYPE)))
371 		return -EFAULT;
372 
373 	return sizeof(struct JS_DATA_TYPE);
374 }
375 
376 static inline int joydev_data_pending(struct joydev_client *client)
377 {
378 	struct joydev *joydev = client->joydev;
379 
380 	return client->startup < joydev->nabs + joydev->nkey ||
381 		client->head != client->tail;
382 }
383 
384 static ssize_t joydev_read(struct file *file, char __user *buf,
385 			   size_t count, loff_t *ppos)
386 {
387 	struct joydev_client *client = file->private_data;
388 	struct joydev *joydev = client->joydev;
389 	struct input_dev *input = joydev->handle.dev;
390 	struct js_event event;
391 	int retval;
392 
393 	if (!joydev->exist)
394 		return -ENODEV;
395 
396 	if (count < sizeof(struct js_event))
397 		return -EINVAL;
398 
399 	if (count == sizeof(struct JS_DATA_TYPE))
400 		return joydev_0x_read(client, input, buf);
401 
402 	if (!joydev_data_pending(client) && (file->f_flags & O_NONBLOCK))
403 		return -EAGAIN;
404 
405 	retval = wait_event_interruptible(joydev->wait,
406 			!joydev->exist || joydev_data_pending(client));
407 	if (retval)
408 		return retval;
409 
410 	if (!joydev->exist)
411 		return -ENODEV;
412 
413 	while (retval + sizeof(struct js_event) <= count &&
414 	       joydev_generate_startup_event(client, input, &event)) {
415 
416 		if (copy_to_user(buf + retval, &event, sizeof(struct js_event)))
417 			return -EFAULT;
418 
419 		retval += sizeof(struct js_event);
420 	}
421 
422 	while (retval + sizeof(struct js_event) <= count &&
423 	       joydev_fetch_next_event(client, &event)) {
424 
425 		if (copy_to_user(buf + retval, &event, sizeof(struct js_event)))
426 			return -EFAULT;
427 
428 		retval += sizeof(struct js_event);
429 	}
430 
431 	return retval;
432 }
433 
434 /* No kernel lock - fine */
435 static __poll_t joydev_poll(struct file *file, poll_table *wait)
436 {
437 	struct joydev_client *client = file->private_data;
438 	struct joydev *joydev = client->joydev;
439 
440 	poll_wait(file, &joydev->wait, wait);
441 	return (joydev_data_pending(client) ? (EPOLLIN | EPOLLRDNORM) : 0) |
442 		(joydev->exist ?  0 : (EPOLLHUP | EPOLLERR));
443 }
444 
445 static int joydev_handle_JSIOCSAXMAP(struct joydev *joydev,
446 				     void __user *argp, size_t len)
447 {
448 	__u8 *abspam;
449 	int i;
450 	int retval = 0;
451 
452 	len = min(len, sizeof(joydev->abspam));
453 
454 	/* Validate the map. */
455 	abspam = memdup_user(argp, len);
456 	if (IS_ERR(abspam))
457 		return PTR_ERR(abspam);
458 
459 	for (i = 0; i < len && i < joydev->nabs; i++) {
460 		if (abspam[i] > ABS_MAX) {
461 			retval = -EINVAL;
462 			goto out;
463 		}
464 	}
465 
466 	memcpy(joydev->abspam, abspam, len);
467 
468 	for (i = 0; i < joydev->nabs; i++)
469 		joydev->absmap[joydev->abspam[i]] = i;
470 
471  out:
472 	kfree(abspam);
473 	return retval;
474 }
475 
476 static int joydev_handle_JSIOCSBTNMAP(struct joydev *joydev,
477 				      void __user *argp, size_t len)
478 {
479 	__u16 *keypam;
480 	int i;
481 	int retval = 0;
482 
483 	if (len % sizeof(*keypam))
484 		return -EINVAL;
485 
486 	len = min(len, sizeof(joydev->keypam));
487 
488 	/* Validate the map. */
489 	keypam = memdup_user(argp, len);
490 	if (IS_ERR(keypam))
491 		return PTR_ERR(keypam);
492 
493 	for (i = 0; i < (len / 2) && i < joydev->nkey; i++) {
494 		if (keypam[i] > KEY_MAX || keypam[i] < BTN_MISC) {
495 			retval = -EINVAL;
496 			goto out;
497 		}
498 	}
499 
500 	memcpy(joydev->keypam, keypam, len);
501 
502 	for (i = 0; i < joydev->nkey; i++)
503 		joydev->keymap[keypam[i] - BTN_MISC] = i;
504 
505  out:
506 	kfree(keypam);
507 	return retval;
508 }
509 
510 
511 static int joydev_ioctl_common(struct joydev *joydev,
512 				unsigned int cmd, void __user *argp)
513 {
514 	struct input_dev *dev = joydev->handle.dev;
515 	size_t len;
516 	int i;
517 	const char *name;
518 
519 	/* Process fixed-sized commands. */
520 	switch (cmd) {
521 
522 	case JS_SET_CAL:
523 		return copy_from_user(&joydev->glue.JS_CORR, argp,
524 				sizeof(joydev->glue.JS_CORR)) ? -EFAULT : 0;
525 
526 	case JS_GET_CAL:
527 		return copy_to_user(argp, &joydev->glue.JS_CORR,
528 				sizeof(joydev->glue.JS_CORR)) ? -EFAULT : 0;
529 
530 	case JS_SET_TIMEOUT:
531 		return get_user(joydev->glue.JS_TIMEOUT, (s32 __user *) argp);
532 
533 	case JS_GET_TIMEOUT:
534 		return put_user(joydev->glue.JS_TIMEOUT, (s32 __user *) argp);
535 
536 	case JSIOCGVERSION:
537 		return put_user(JS_VERSION, (__u32 __user *) argp);
538 
539 	case JSIOCGAXES:
540 		return put_user(joydev->nabs, (__u8 __user *) argp);
541 
542 	case JSIOCGBUTTONS:
543 		return put_user(joydev->nkey, (__u8 __user *) argp);
544 
545 	case JSIOCSCORR:
546 		if (copy_from_user(joydev->corr, argp,
547 			      sizeof(joydev->corr[0]) * joydev->nabs))
548 			return -EFAULT;
549 
550 		for (i = 0; i < joydev->nabs; i++) {
551 			int val = input_abs_get_val(dev, joydev->abspam[i]);
552 			joydev->abs[i] = joydev_correct(val, &joydev->corr[i]);
553 		}
554 		return 0;
555 
556 	case JSIOCGCORR:
557 		return copy_to_user(argp, joydev->corr,
558 			sizeof(joydev->corr[0]) * joydev->nabs) ? -EFAULT : 0;
559 
560 	}
561 
562 	/*
563 	 * Process variable-sized commands (the axis and button map commands
564 	 * are considered variable-sized to decouple them from the values of
565 	 * ABS_MAX and KEY_MAX).
566 	 */
567 	switch (cmd & ~IOCSIZE_MASK) {
568 
569 	case (JSIOCSAXMAP & ~IOCSIZE_MASK):
570 		return joydev_handle_JSIOCSAXMAP(joydev, argp, _IOC_SIZE(cmd));
571 
572 	case (JSIOCGAXMAP & ~IOCSIZE_MASK):
573 		len = min_t(size_t, _IOC_SIZE(cmd), sizeof(joydev->abspam));
574 		return copy_to_user(argp, joydev->abspam, len) ? -EFAULT : len;
575 
576 	case (JSIOCSBTNMAP & ~IOCSIZE_MASK):
577 		return joydev_handle_JSIOCSBTNMAP(joydev, argp, _IOC_SIZE(cmd));
578 
579 	case (JSIOCGBTNMAP & ~IOCSIZE_MASK):
580 		len = min_t(size_t, _IOC_SIZE(cmd), sizeof(joydev->keypam));
581 		return copy_to_user(argp, joydev->keypam, len) ? -EFAULT : len;
582 
583 	case JSIOCGNAME(0):
584 		name = dev->name;
585 		if (!name)
586 			return 0;
587 
588 		len = min_t(size_t, _IOC_SIZE(cmd), strlen(name) + 1);
589 		return copy_to_user(argp, name, len) ? -EFAULT : len;
590 	}
591 
592 	return -EINVAL;
593 }
594 
595 #ifdef CONFIG_COMPAT
596 static long joydev_compat_ioctl(struct file *file,
597 				unsigned int cmd, unsigned long arg)
598 {
599 	struct joydev_client *client = file->private_data;
600 	struct joydev *joydev = client->joydev;
601 	void __user *argp = (void __user *)arg;
602 	s32 tmp32;
603 	struct JS_DATA_SAVE_TYPE_32 ds32;
604 	int retval;
605 
606 	retval = mutex_lock_interruptible(&joydev->mutex);
607 	if (retval)
608 		return retval;
609 
610 	if (!joydev->exist) {
611 		retval = -ENODEV;
612 		goto out;
613 	}
614 
615 	switch (cmd) {
616 
617 	case JS_SET_TIMELIMIT:
618 		retval = get_user(tmp32, (s32 __user *) arg);
619 		if (retval == 0)
620 			joydev->glue.JS_TIMELIMIT = tmp32;
621 		break;
622 
623 	case JS_GET_TIMELIMIT:
624 		tmp32 = joydev->glue.JS_TIMELIMIT;
625 		retval = put_user(tmp32, (s32 __user *) arg);
626 		break;
627 
628 	case JS_SET_ALL:
629 		retval = copy_from_user(&ds32, argp,
630 					sizeof(ds32)) ? -EFAULT : 0;
631 		if (retval == 0) {
632 			joydev->glue.JS_TIMEOUT    = ds32.JS_TIMEOUT;
633 			joydev->glue.BUSY          = ds32.BUSY;
634 			joydev->glue.JS_EXPIRETIME = ds32.JS_EXPIRETIME;
635 			joydev->glue.JS_TIMELIMIT  = ds32.JS_TIMELIMIT;
636 			joydev->glue.JS_SAVE       = ds32.JS_SAVE;
637 			joydev->glue.JS_CORR       = ds32.JS_CORR;
638 		}
639 		break;
640 
641 	case JS_GET_ALL:
642 		ds32.JS_TIMEOUT    = joydev->glue.JS_TIMEOUT;
643 		ds32.BUSY          = joydev->glue.BUSY;
644 		ds32.JS_EXPIRETIME = joydev->glue.JS_EXPIRETIME;
645 		ds32.JS_TIMELIMIT  = joydev->glue.JS_TIMELIMIT;
646 		ds32.JS_SAVE       = joydev->glue.JS_SAVE;
647 		ds32.JS_CORR       = joydev->glue.JS_CORR;
648 
649 		retval = copy_to_user(argp, &ds32, sizeof(ds32)) ? -EFAULT : 0;
650 		break;
651 
652 	default:
653 		retval = joydev_ioctl_common(joydev, cmd, argp);
654 		break;
655 	}
656 
657  out:
658 	mutex_unlock(&joydev->mutex);
659 	return retval;
660 }
661 #endif /* CONFIG_COMPAT */
662 
663 static long joydev_ioctl(struct file *file,
664 			 unsigned int cmd, unsigned long arg)
665 {
666 	struct joydev_client *client = file->private_data;
667 	struct joydev *joydev = client->joydev;
668 	void __user *argp = (void __user *)arg;
669 	int retval;
670 
671 	retval = mutex_lock_interruptible(&joydev->mutex);
672 	if (retval)
673 		return retval;
674 
675 	if (!joydev->exist) {
676 		retval = -ENODEV;
677 		goto out;
678 	}
679 
680 	switch (cmd) {
681 
682 	case JS_SET_TIMELIMIT:
683 		retval = get_user(joydev->glue.JS_TIMELIMIT,
684 				  (long __user *) arg);
685 		break;
686 
687 	case JS_GET_TIMELIMIT:
688 		retval = put_user(joydev->glue.JS_TIMELIMIT,
689 				  (long __user *) arg);
690 		break;
691 
692 	case JS_SET_ALL:
693 		retval = copy_from_user(&joydev->glue, argp,
694 					sizeof(joydev->glue)) ? -EFAULT : 0;
695 		break;
696 
697 	case JS_GET_ALL:
698 		retval = copy_to_user(argp, &joydev->glue,
699 				      sizeof(joydev->glue)) ? -EFAULT : 0;
700 		break;
701 
702 	default:
703 		retval = joydev_ioctl_common(joydev, cmd, argp);
704 		break;
705 	}
706  out:
707 	mutex_unlock(&joydev->mutex);
708 	return retval;
709 }
710 
711 static const struct file_operations joydev_fops = {
712 	.owner		= THIS_MODULE,
713 	.read		= joydev_read,
714 	.poll		= joydev_poll,
715 	.open		= joydev_open,
716 	.release	= joydev_release,
717 	.unlocked_ioctl	= joydev_ioctl,
718 #ifdef CONFIG_COMPAT
719 	.compat_ioctl	= joydev_compat_ioctl,
720 #endif
721 	.fasync		= joydev_fasync,
722 	.llseek		= no_llseek,
723 };
724 
725 /*
726  * Mark device non-existent. This disables writes, ioctls and
727  * prevents new users from opening the device. Already posted
728  * blocking reads will stay, however new ones will fail.
729  */
730 static void joydev_mark_dead(struct joydev *joydev)
731 {
732 	mutex_lock(&joydev->mutex);
733 	joydev->exist = false;
734 	mutex_unlock(&joydev->mutex);
735 }
736 
737 static void joydev_cleanup(struct joydev *joydev)
738 {
739 	struct input_handle *handle = &joydev->handle;
740 
741 	joydev_mark_dead(joydev);
742 	joydev_hangup(joydev);
743 
744 	/* joydev is marked dead so no one else accesses joydev->open */
745 	if (joydev->open)
746 		input_close_device(handle);
747 }
748 
749 /*
750  * These codes are copied from from hid-ids.h, unfortunately there is no common
751  * usb_ids/bt_ids.h header.
752  */
753 #define USB_VENDOR_ID_SONY			0x054c
754 #define USB_DEVICE_ID_SONY_PS3_CONTROLLER		0x0268
755 #define USB_DEVICE_ID_SONY_PS4_CONTROLLER		0x05c4
756 #define USB_DEVICE_ID_SONY_PS4_CONTROLLER_2		0x09cc
757 #define USB_DEVICE_ID_SONY_PS4_CONTROLLER_DONGLE	0x0ba0
758 
759 #define USB_VENDOR_ID_THQ			0x20d6
760 #define USB_DEVICE_ID_THQ_PS3_UDRAW			0xcb17
761 
762 #define ACCEL_DEV(vnd, prd)						\
763 	{								\
764 		.flags = INPUT_DEVICE_ID_MATCH_VENDOR |			\
765 				INPUT_DEVICE_ID_MATCH_PRODUCT |		\
766 				INPUT_DEVICE_ID_MATCH_PROPBIT,		\
767 		.vendor = (vnd),					\
768 		.product = (prd),					\
769 		.propbit = { BIT_MASK(INPUT_PROP_ACCELEROMETER) },	\
770 	}
771 
772 static const struct input_device_id joydev_blacklist[] = {
773 	/* Avoid touchpads and touchscreens */
774 	{
775 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
776 				INPUT_DEVICE_ID_MATCH_KEYBIT,
777 		.evbit = { BIT_MASK(EV_KEY) },
778 		.keybit = { [BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH) },
779 	},
780 	/* Avoid tablets, digitisers and similar devices */
781 	{
782 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
783 				INPUT_DEVICE_ID_MATCH_KEYBIT,
784 		.evbit = { BIT_MASK(EV_KEY) },
785 		.keybit = { [BIT_WORD(BTN_DIGI)] = BIT_MASK(BTN_DIGI) },
786 	},
787 	/* Disable accelerometers on composite devices */
788 	ACCEL_DEV(USB_VENDOR_ID_SONY, USB_DEVICE_ID_SONY_PS3_CONTROLLER),
789 	ACCEL_DEV(USB_VENDOR_ID_SONY, USB_DEVICE_ID_SONY_PS4_CONTROLLER),
790 	ACCEL_DEV(USB_VENDOR_ID_SONY, USB_DEVICE_ID_SONY_PS4_CONTROLLER_2),
791 	ACCEL_DEV(USB_VENDOR_ID_SONY, USB_DEVICE_ID_SONY_PS4_CONTROLLER_DONGLE),
792 	ACCEL_DEV(USB_VENDOR_ID_THQ, USB_DEVICE_ID_THQ_PS3_UDRAW),
793 	{ /* sentinel */ }
794 };
795 
796 static bool joydev_dev_is_blacklisted(struct input_dev *dev)
797 {
798 	const struct input_device_id *id;
799 
800 	for (id = joydev_blacklist; id->flags; id++) {
801 		if (input_match_device_id(dev, id)) {
802 			dev_dbg(&dev->dev,
803 				"joydev: blacklisting '%s'\n", dev->name);
804 			return true;
805 		}
806 	}
807 
808 	return false;
809 }
810 
811 static bool joydev_dev_is_absolute_mouse(struct input_dev *dev)
812 {
813 	DECLARE_BITMAP(jd_scratch, KEY_CNT);
814 	bool ev_match = false;
815 
816 	BUILD_BUG_ON(ABS_CNT > KEY_CNT || EV_CNT > KEY_CNT);
817 
818 	/*
819 	 * Virtualization (VMware, etc) and remote management (HP
820 	 * ILO2) solutions use absolute coordinates for their virtual
821 	 * pointing devices so that there is one-to-one relationship
822 	 * between pointer position on the host screen and virtual
823 	 * guest screen, and so their mice use ABS_X, ABS_Y and 3
824 	 * primary button events. This clashes with what joydev
825 	 * considers to be joysticks (a device with at minimum ABS_X
826 	 * axis).
827 	 *
828 	 * Here we are trying to separate absolute mice from
829 	 * joysticks. A device is, for joystick detection purposes,
830 	 * considered to be an absolute mouse if the following is
831 	 * true:
832 	 *
833 	 * 1) Event types are exactly
834 	 *      EV_ABS, EV_KEY and EV_SYN
835 	 *    or
836 	 *      EV_ABS, EV_KEY, EV_SYN and EV_MSC
837 	 *    or
838 	 *      EV_ABS, EV_KEY, EV_SYN, EV_MSC and EV_REL.
839 	 * 2) Absolute events are exactly ABS_X and ABS_Y.
840 	 * 3) Keys are exactly BTN_LEFT, BTN_RIGHT and BTN_MIDDLE.
841 	 * 4) Device is not on "Amiga" bus.
842 	 */
843 
844 	bitmap_zero(jd_scratch, EV_CNT);
845 	/* VMware VMMouse, HP ILO2 */
846 	__set_bit(EV_ABS, jd_scratch);
847 	__set_bit(EV_KEY, jd_scratch);
848 	__set_bit(EV_SYN, jd_scratch);
849 	if (bitmap_equal(jd_scratch, dev->evbit, EV_CNT))
850 		ev_match = true;
851 
852 	/* HP ILO2, AMI BMC firmware */
853 	__set_bit(EV_MSC, jd_scratch);
854 	if (bitmap_equal(jd_scratch, dev->evbit, EV_CNT))
855 		ev_match = true;
856 
857 	/* VMware Virtual USB Mouse, QEMU USB Tablet, ATEN BMC firmware */
858 	__set_bit(EV_REL, jd_scratch);
859 	if (bitmap_equal(jd_scratch, dev->evbit, EV_CNT))
860 		ev_match = true;
861 
862 	if (!ev_match)
863 		return false;
864 
865 	bitmap_zero(jd_scratch, ABS_CNT);
866 	__set_bit(ABS_X, jd_scratch);
867 	__set_bit(ABS_Y, jd_scratch);
868 	if (!bitmap_equal(dev->absbit, jd_scratch, ABS_CNT))
869 		return false;
870 
871 	bitmap_zero(jd_scratch, KEY_CNT);
872 	__set_bit(BTN_LEFT, jd_scratch);
873 	__set_bit(BTN_RIGHT, jd_scratch);
874 	__set_bit(BTN_MIDDLE, jd_scratch);
875 
876 	if (!bitmap_equal(dev->keybit, jd_scratch, KEY_CNT))
877 		return false;
878 
879 	/*
880 	 * Amiga joystick (amijoy) historically uses left/middle/right
881 	 * button events.
882 	 */
883 	if (dev->id.bustype == BUS_AMIGA)
884 		return false;
885 
886 	return true;
887 }
888 
889 static bool joydev_match(struct input_handler *handler, struct input_dev *dev)
890 {
891 	/* Disable blacklisted devices */
892 	if (joydev_dev_is_blacklisted(dev))
893 		return false;
894 
895 	/* Avoid absolute mice */
896 	if (joydev_dev_is_absolute_mouse(dev))
897 		return false;
898 
899 	return true;
900 }
901 
902 static int joydev_connect(struct input_handler *handler, struct input_dev *dev,
903 			  const struct input_device_id *id)
904 {
905 	struct joydev *joydev;
906 	int i, j, t, minor, dev_no;
907 	int error;
908 
909 	minor = input_get_new_minor(JOYDEV_MINOR_BASE, JOYDEV_MINORS, true);
910 	if (minor < 0) {
911 		error = minor;
912 		pr_err("failed to reserve new minor: %d\n", error);
913 		return error;
914 	}
915 
916 	joydev = kzalloc(sizeof(struct joydev), GFP_KERNEL);
917 	if (!joydev) {
918 		error = -ENOMEM;
919 		goto err_free_minor;
920 	}
921 
922 	INIT_LIST_HEAD(&joydev->client_list);
923 	spin_lock_init(&joydev->client_lock);
924 	mutex_init(&joydev->mutex);
925 	init_waitqueue_head(&joydev->wait);
926 	joydev->exist = true;
927 
928 	dev_no = minor;
929 	/* Normalize device number if it falls into legacy range */
930 	if (dev_no < JOYDEV_MINOR_BASE + JOYDEV_MINORS)
931 		dev_no -= JOYDEV_MINOR_BASE;
932 	dev_set_name(&joydev->dev, "js%d", dev_no);
933 
934 	joydev->handle.dev = input_get_device(dev);
935 	joydev->handle.name = dev_name(&joydev->dev);
936 	joydev->handle.handler = handler;
937 	joydev->handle.private = joydev;
938 
939 	for_each_set_bit(i, dev->absbit, ABS_CNT) {
940 		joydev->absmap[i] = joydev->nabs;
941 		joydev->abspam[joydev->nabs] = i;
942 		joydev->nabs++;
943 	}
944 
945 	for (i = BTN_JOYSTICK - BTN_MISC; i < KEY_MAX - BTN_MISC + 1; i++)
946 		if (test_bit(i + BTN_MISC, dev->keybit)) {
947 			joydev->keymap[i] = joydev->nkey;
948 			joydev->keypam[joydev->nkey] = i + BTN_MISC;
949 			joydev->nkey++;
950 		}
951 
952 	for (i = 0; i < BTN_JOYSTICK - BTN_MISC; i++)
953 		if (test_bit(i + BTN_MISC, dev->keybit)) {
954 			joydev->keymap[i] = joydev->nkey;
955 			joydev->keypam[joydev->nkey] = i + BTN_MISC;
956 			joydev->nkey++;
957 		}
958 
959 	for (i = 0; i < joydev->nabs; i++) {
960 		j = joydev->abspam[i];
961 		if (input_abs_get_max(dev, j) == input_abs_get_min(dev, j)) {
962 			joydev->corr[i].type = JS_CORR_NONE;
963 			continue;
964 		}
965 		joydev->corr[i].type = JS_CORR_BROKEN;
966 		joydev->corr[i].prec = input_abs_get_fuzz(dev, j);
967 
968 		t = (input_abs_get_max(dev, j) + input_abs_get_min(dev, j)) / 2;
969 		joydev->corr[i].coef[0] = t - input_abs_get_flat(dev, j);
970 		joydev->corr[i].coef[1] = t + input_abs_get_flat(dev, j);
971 
972 		t = (input_abs_get_max(dev, j) - input_abs_get_min(dev, j)) / 2
973 			- 2 * input_abs_get_flat(dev, j);
974 		if (t) {
975 			joydev->corr[i].coef[2] = (1 << 29) / t;
976 			joydev->corr[i].coef[3] = (1 << 29) / t;
977 		}
978 	}
979 
980 	joydev->dev.devt = MKDEV(INPUT_MAJOR, minor);
981 	joydev->dev.class = &input_class;
982 	joydev->dev.parent = &dev->dev;
983 	joydev->dev.release = joydev_free;
984 	device_initialize(&joydev->dev);
985 
986 	error = input_register_handle(&joydev->handle);
987 	if (error)
988 		goto err_free_joydev;
989 
990 	cdev_init(&joydev->cdev, &joydev_fops);
991 
992 	error = cdev_device_add(&joydev->cdev, &joydev->dev);
993 	if (error)
994 		goto err_cleanup_joydev;
995 
996 	return 0;
997 
998  err_cleanup_joydev:
999 	joydev_cleanup(joydev);
1000 	input_unregister_handle(&joydev->handle);
1001  err_free_joydev:
1002 	put_device(&joydev->dev);
1003  err_free_minor:
1004 	input_free_minor(minor);
1005 	return error;
1006 }
1007 
1008 static void joydev_disconnect(struct input_handle *handle)
1009 {
1010 	struct joydev *joydev = handle->private;
1011 
1012 	cdev_device_del(&joydev->cdev, &joydev->dev);
1013 	joydev_cleanup(joydev);
1014 	input_free_minor(MINOR(joydev->dev.devt));
1015 	input_unregister_handle(handle);
1016 	put_device(&joydev->dev);
1017 }
1018 
1019 static const struct input_device_id joydev_ids[] = {
1020 	{
1021 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1022 				INPUT_DEVICE_ID_MATCH_ABSBIT,
1023 		.evbit = { BIT_MASK(EV_ABS) },
1024 		.absbit = { BIT_MASK(ABS_X) },
1025 	},
1026 	{
1027 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1028 				INPUT_DEVICE_ID_MATCH_ABSBIT,
1029 		.evbit = { BIT_MASK(EV_ABS) },
1030 		.absbit = { BIT_MASK(ABS_Z) },
1031 	},
1032 	{
1033 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1034 				INPUT_DEVICE_ID_MATCH_ABSBIT,
1035 		.evbit = { BIT_MASK(EV_ABS) },
1036 		.absbit = { BIT_MASK(ABS_WHEEL) },
1037 	},
1038 	{
1039 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1040 				INPUT_DEVICE_ID_MATCH_ABSBIT,
1041 		.evbit = { BIT_MASK(EV_ABS) },
1042 		.absbit = { BIT_MASK(ABS_THROTTLE) },
1043 	},
1044 	{
1045 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1046 				INPUT_DEVICE_ID_MATCH_KEYBIT,
1047 		.evbit = { BIT_MASK(EV_KEY) },
1048 		.keybit = {[BIT_WORD(BTN_JOYSTICK)] = BIT_MASK(BTN_JOYSTICK) },
1049 	},
1050 	{
1051 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1052 				INPUT_DEVICE_ID_MATCH_KEYBIT,
1053 		.evbit = { BIT_MASK(EV_KEY) },
1054 		.keybit = { [BIT_WORD(BTN_GAMEPAD)] = BIT_MASK(BTN_GAMEPAD) },
1055 	},
1056 	{
1057 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1058 				INPUT_DEVICE_ID_MATCH_KEYBIT,
1059 		.evbit = { BIT_MASK(EV_KEY) },
1060 		.keybit = { [BIT_WORD(BTN_TRIGGER_HAPPY)] = BIT_MASK(BTN_TRIGGER_HAPPY) },
1061 	},
1062 	{ }	/* Terminating entry */
1063 };
1064 
1065 MODULE_DEVICE_TABLE(input, joydev_ids);
1066 
1067 static struct input_handler joydev_handler = {
1068 	.event		= joydev_event,
1069 	.match		= joydev_match,
1070 	.connect	= joydev_connect,
1071 	.disconnect	= joydev_disconnect,
1072 	.legacy_minors	= true,
1073 	.minor		= JOYDEV_MINOR_BASE,
1074 	.name		= "joydev",
1075 	.id_table	= joydev_ids,
1076 };
1077 
1078 static int __init joydev_init(void)
1079 {
1080 	return input_register_handler(&joydev_handler);
1081 }
1082 
1083 static void __exit joydev_exit(void)
1084 {
1085 	input_unregister_handler(&joydev_handler);
1086 }
1087 
1088 module_init(joydev_init);
1089 module_exit(joydev_exit);
1090