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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 
joydev_correct(int value,struct js_corr * corr)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 
joydev_pass_event(struct joydev_client * client,struct js_event * event)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 
joydev_event(struct input_handle * handle,unsigned int type,unsigned int code,int value)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 
joydev_fasync(int fd,struct file * file,int on)160 static int joydev_fasync(int fd, struct file *file, int on)
161 {
162 	int retval;
163 	struct joydev_client *client = file->private_data;
164 
165 	retval = fasync_helper(fd, file, on, &client->fasync);
166 
167 	return retval < 0 ? retval : 0;
168 }
169 
joydev_free(struct device * dev)170 static void joydev_free(struct device *dev)
171 {
172 	struct joydev *joydev = container_of(dev, struct joydev, dev);
173 
174 	input_put_device(joydev->handle.dev);
175 	kfree(joydev);
176 }
177 
joydev_attach_client(struct joydev * joydev,struct joydev_client * client)178 static void joydev_attach_client(struct joydev *joydev,
179 				 struct joydev_client *client)
180 {
181 	spin_lock(&joydev->client_lock);
182 	list_add_tail_rcu(&client->node, &joydev->client_list);
183 	spin_unlock(&joydev->client_lock);
184 	synchronize_rcu();
185 }
186 
joydev_detach_client(struct joydev * joydev,struct joydev_client * client)187 static void joydev_detach_client(struct joydev *joydev,
188 				 struct joydev_client *client)
189 {
190 	spin_lock(&joydev->client_lock);
191 	list_del_rcu(&client->node);
192 	spin_unlock(&joydev->client_lock);
193 	synchronize_rcu();
194 }
195 
joydev_open_device(struct joydev * joydev)196 static int joydev_open_device(struct joydev *joydev)
197 {
198 	int retval;
199 
200 	retval = mutex_lock_interruptible(&joydev->mutex);
201 	if (retval)
202 		return retval;
203 
204 	if (!joydev->exist)
205 		retval = -ENODEV;
206 	else if (!joydev->open++) {
207 		retval = input_open_device(&joydev->handle);
208 		if (retval)
209 			joydev->open--;
210 	}
211 
212 	mutex_unlock(&joydev->mutex);
213 	return retval;
214 }
215 
joydev_close_device(struct joydev * joydev)216 static void joydev_close_device(struct joydev *joydev)
217 {
218 	mutex_lock(&joydev->mutex);
219 
220 	if (joydev->exist && !--joydev->open)
221 		input_close_device(&joydev->handle);
222 
223 	mutex_unlock(&joydev->mutex);
224 }
225 
226 /*
227  * Wake up users waiting for IO so they can disconnect from
228  * dead device.
229  */
joydev_hangup(struct joydev * joydev)230 static void joydev_hangup(struct joydev *joydev)
231 {
232 	struct joydev_client *client;
233 
234 	spin_lock(&joydev->client_lock);
235 	list_for_each_entry(client, &joydev->client_list, node)
236 		kill_fasync(&client->fasync, SIGIO, POLL_HUP);
237 	spin_unlock(&joydev->client_lock);
238 
239 	wake_up_interruptible(&joydev->wait);
240 }
241 
joydev_release(struct inode * inode,struct file * file)242 static int joydev_release(struct inode *inode, struct file *file)
243 {
244 	struct joydev_client *client = file->private_data;
245 	struct joydev *joydev = client->joydev;
246 
247 	joydev_detach_client(joydev, client);
248 	kfree(client);
249 
250 	joydev_close_device(joydev);
251 	put_device(&joydev->dev);
252 
253 	return 0;
254 }
255 
joydev_open(struct inode * inode,struct file * file)256 static int joydev_open(struct inode *inode, struct file *file)
257 {
258 	struct joydev_client *client;
259 	struct joydev *joydev;
260 	int i = iminor(inode) - JOYDEV_MINOR_BASE;
261 	int error;
262 
263 	if (i >= JOYDEV_MINORS)
264 		return -ENODEV;
265 
266 	error = mutex_lock_interruptible(&joydev_table_mutex);
267 	if (error)
268 		return error;
269 	joydev = joydev_table[i];
270 	if (joydev)
271 		get_device(&joydev->dev);
272 	mutex_unlock(&joydev_table_mutex);
273 
274 	if (!joydev)
275 		return -ENODEV;
276 
277 	client = kzalloc(sizeof(struct joydev_client), GFP_KERNEL);
278 	if (!client) {
279 		error = -ENOMEM;
280 		goto err_put_joydev;
281 	}
282 
283 	spin_lock_init(&client->buffer_lock);
284 	client->joydev = joydev;
285 	joydev_attach_client(joydev, client);
286 
287 	error = joydev_open_device(joydev);
288 	if (error)
289 		goto err_free_client;
290 
291 	file->private_data = client;
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 
joydev_generate_startup_event(struct joydev_client * client,struct input_dev * input,struct js_event * event)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 
joydev_fetch_next_event(struct joydev_client * client,struct js_event * event)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  */
joydev_0x_read(struct joydev_client * client,struct input_dev * input,char __user * buf)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 
joydev_data_pending(struct joydev_client * client)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 
joydev_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)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 */
joydev_poll(struct file * file,poll_table * wait)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 
joydev_ioctl_common(struct joydev * joydev,unsigned int cmd,void __user * argp)459 static int joydev_ioctl_common(struct joydev *joydev,
460 				unsigned int cmd, void __user *argp)
461 {
462 	struct input_dev *dev = joydev->handle.dev;
463 	int i, j;
464 
465 	switch (cmd) {
466 
467 	case JS_SET_CAL:
468 		return copy_from_user(&joydev->glue.JS_CORR, argp,
469 				sizeof(joydev->glue.JS_CORR)) ? -EFAULT : 0;
470 
471 	case JS_GET_CAL:
472 		return copy_to_user(argp, &joydev->glue.JS_CORR,
473 				sizeof(joydev->glue.JS_CORR)) ? -EFAULT : 0;
474 
475 	case JS_SET_TIMEOUT:
476 		return get_user(joydev->glue.JS_TIMEOUT, (s32 __user *) argp);
477 
478 	case JS_GET_TIMEOUT:
479 		return put_user(joydev->glue.JS_TIMEOUT, (s32 __user *) argp);
480 
481 	case JSIOCGVERSION:
482 		return put_user(JS_VERSION, (__u32 __user *) argp);
483 
484 	case JSIOCGAXES:
485 		return put_user(joydev->nabs, (__u8 __user *) argp);
486 
487 	case JSIOCGBUTTONS:
488 		return put_user(joydev->nkey, (__u8 __user *) argp);
489 
490 	case JSIOCSCORR:
491 		if (copy_from_user(joydev->corr, argp,
492 			      sizeof(joydev->corr[0]) * joydev->nabs))
493 		    return -EFAULT;
494 
495 		for (i = 0; i < joydev->nabs; i++) {
496 			j = joydev->abspam[i];
497 			joydev->abs[i] = joydev_correct(dev->abs[j],
498 							&joydev->corr[i]);
499 		}
500 		return 0;
501 
502 	case JSIOCGCORR:
503 		return copy_to_user(argp, joydev->corr,
504 			sizeof(joydev->corr[0]) * joydev->nabs) ? -EFAULT : 0;
505 
506 	case JSIOCSAXMAP:
507 		if (copy_from_user(joydev->abspam, argp,
508 				   sizeof(__u8) * (ABS_MAX + 1)))
509 			return -EFAULT;
510 
511 		for (i = 0; i < joydev->nabs; i++) {
512 			if (joydev->abspam[i] > ABS_MAX)
513 				return -EINVAL;
514 			joydev->absmap[joydev->abspam[i]] = i;
515 		}
516 		return 0;
517 
518 	case JSIOCGAXMAP:
519 		return copy_to_user(argp, joydev->abspam,
520 			sizeof(__u8) * (ABS_MAX + 1)) ? -EFAULT : 0;
521 
522 	case JSIOCSBTNMAP:
523 		if (copy_from_user(joydev->keypam, argp,
524 				   sizeof(__u16) * (KEY_MAX - BTN_MISC + 1)))
525 			return -EFAULT;
526 
527 		for (i = 0; i < joydev->nkey; i++) {
528 			if (joydev->keypam[i] > KEY_MAX ||
529 			    joydev->keypam[i] < BTN_MISC)
530 				return -EINVAL;
531 			joydev->keymap[joydev->keypam[i] - BTN_MISC] = i;
532 		}
533 
534 		return 0;
535 
536 	case JSIOCGBTNMAP:
537 		return copy_to_user(argp, joydev->keypam,
538 			sizeof(__u16) * (KEY_MAX - BTN_MISC + 1)) ? -EFAULT : 0;
539 
540 	default:
541 		if ((cmd & ~IOCSIZE_MASK) == JSIOCGNAME(0)) {
542 			int len;
543 			if (!dev->name)
544 				return 0;
545 			len = strlen(dev->name) + 1;
546 			if (len > _IOC_SIZE(cmd))
547 				len = _IOC_SIZE(cmd);
548 			if (copy_to_user(argp, dev->name, len))
549 				return -EFAULT;
550 			return len;
551 		}
552 	}
553 	return -EINVAL;
554 }
555 
556 #ifdef CONFIG_COMPAT
joydev_compat_ioctl(struct file * file,unsigned int cmd,unsigned long arg)557 static long joydev_compat_ioctl(struct file *file,
558 				unsigned int cmd, unsigned long arg)
559 {
560 	struct joydev_client *client = file->private_data;
561 	struct joydev *joydev = client->joydev;
562 	void __user *argp = (void __user *)arg;
563 	s32 tmp32;
564 	struct JS_DATA_SAVE_TYPE_32 ds32;
565 	int retval;
566 
567 	retval = mutex_lock_interruptible(&joydev->mutex);
568 	if (retval)
569 		return retval;
570 
571 	if (!joydev->exist) {
572 		retval = -ENODEV;
573 		goto out;
574 	}
575 
576 	switch (cmd) {
577 
578 	case JS_SET_TIMELIMIT:
579 		retval = get_user(tmp32, (s32 __user *) arg);
580 		if (retval == 0)
581 			joydev->glue.JS_TIMELIMIT = tmp32;
582 		break;
583 
584 	case JS_GET_TIMELIMIT:
585 		tmp32 = joydev->glue.JS_TIMELIMIT;
586 		retval = put_user(tmp32, (s32 __user *) arg);
587 		break;
588 
589 	case JS_SET_ALL:
590 		retval = copy_from_user(&ds32, argp,
591 					sizeof(ds32)) ? -EFAULT : 0;
592 		if (retval == 0) {
593 			joydev->glue.JS_TIMEOUT    = ds32.JS_TIMEOUT;
594 			joydev->glue.BUSY          = ds32.BUSY;
595 			joydev->glue.JS_EXPIRETIME = ds32.JS_EXPIRETIME;
596 			joydev->glue.JS_TIMELIMIT  = ds32.JS_TIMELIMIT;
597 			joydev->glue.JS_SAVE       = ds32.JS_SAVE;
598 			joydev->glue.JS_CORR       = ds32.JS_CORR;
599 		}
600 		break;
601 
602 	case JS_GET_ALL:
603 		ds32.JS_TIMEOUT    = joydev->glue.JS_TIMEOUT;
604 		ds32.BUSY          = joydev->glue.BUSY;
605 		ds32.JS_EXPIRETIME = joydev->glue.JS_EXPIRETIME;
606 		ds32.JS_TIMELIMIT  = joydev->glue.JS_TIMELIMIT;
607 		ds32.JS_SAVE       = joydev->glue.JS_SAVE;
608 		ds32.JS_CORR       = joydev->glue.JS_CORR;
609 
610 		retval = copy_to_user(argp, &ds32, sizeof(ds32)) ? -EFAULT : 0;
611 		break;
612 
613 	default:
614 		retval = joydev_ioctl_common(joydev, cmd, argp);
615 		break;
616 	}
617 
618  out:
619 	mutex_unlock(&joydev->mutex);
620 	return retval;
621 }
622 #endif /* CONFIG_COMPAT */
623 
joydev_ioctl(struct file * file,unsigned int cmd,unsigned long arg)624 static long joydev_ioctl(struct file *file,
625 			 unsigned int cmd, unsigned long arg)
626 {
627 	struct joydev_client *client = file->private_data;
628 	struct joydev *joydev = client->joydev;
629 	void __user *argp = (void __user *)arg;
630 	int retval;
631 
632 	retval = mutex_lock_interruptible(&joydev->mutex);
633 	if (retval)
634 		return retval;
635 
636 	if (!joydev->exist) {
637 		retval = -ENODEV;
638 		goto out;
639 	}
640 
641 	switch (cmd) {
642 
643 	case JS_SET_TIMELIMIT:
644 		retval = get_user(joydev->glue.JS_TIMELIMIT,
645 				  (long __user *) arg);
646 		break;
647 
648 	case JS_GET_TIMELIMIT:
649 		retval = put_user(joydev->glue.JS_TIMELIMIT,
650 				  (long __user *) arg);
651 		break;
652 
653 	case JS_SET_ALL:
654 		retval = copy_from_user(&joydev->glue, argp,
655 					sizeof(joydev->glue)) ? -EFAULT: 0;
656 		break;
657 
658 	case JS_GET_ALL:
659 		retval = copy_to_user(argp, &joydev->glue,
660 				      sizeof(joydev->glue)) ? -EFAULT : 0;
661 		break;
662 
663 	default:
664 		retval = joydev_ioctl_common(joydev, cmd, argp);
665 		break;
666 	}
667  out:
668 	mutex_unlock(&joydev->mutex);
669 	return retval;
670 }
671 
672 static const struct file_operations joydev_fops = {
673 	.owner		= THIS_MODULE,
674 	.read		= joydev_read,
675 	.poll		= joydev_poll,
676 	.open		= joydev_open,
677 	.release	= joydev_release,
678 	.unlocked_ioctl	= joydev_ioctl,
679 #ifdef CONFIG_COMPAT
680 	.compat_ioctl	= joydev_compat_ioctl,
681 #endif
682 	.fasync		= joydev_fasync,
683 };
684 
joydev_install_chrdev(struct joydev * joydev)685 static int joydev_install_chrdev(struct joydev *joydev)
686 {
687 	joydev_table[joydev->minor] = joydev;
688 	return 0;
689 }
690 
joydev_remove_chrdev(struct joydev * joydev)691 static void joydev_remove_chrdev(struct joydev *joydev)
692 {
693 	mutex_lock(&joydev_table_mutex);
694 	joydev_table[joydev->minor] = NULL;
695 	mutex_unlock(&joydev_table_mutex);
696 }
697 
698 /*
699  * Mark device non-existant. This disables writes, ioctls and
700  * prevents new users from opening the device. Already posted
701  * blocking reads will stay, however new ones will fail.
702  */
joydev_mark_dead(struct joydev * joydev)703 static void joydev_mark_dead(struct joydev *joydev)
704 {
705 	mutex_lock(&joydev->mutex);
706 	joydev->exist = 0;
707 	mutex_unlock(&joydev->mutex);
708 }
709 
joydev_cleanup(struct joydev * joydev)710 static void joydev_cleanup(struct joydev *joydev)
711 {
712 	struct input_handle *handle = &joydev->handle;
713 
714 	joydev_mark_dead(joydev);
715 	joydev_hangup(joydev);
716 	joydev_remove_chrdev(joydev);
717 
718 	/* joydev is marked dead so noone else accesses joydev->open */
719 	if (joydev->open)
720 		input_close_device(handle);
721 }
722 
joydev_connect(struct input_handler * handler,struct input_dev * dev,const struct input_device_id * id)723 static int joydev_connect(struct input_handler *handler, struct input_dev *dev,
724 			  const struct input_device_id *id)
725 {
726 	struct joydev *joydev;
727 	int i, j, t, minor;
728 	int error;
729 
730 	for (minor = 0; minor < JOYDEV_MINORS; minor++)
731 		if (!joydev_table[minor])
732 			break;
733 
734 	if (minor == JOYDEV_MINORS) {
735 		printk(KERN_ERR "joydev: no more free joydev devices\n");
736 		return -ENFILE;
737 	}
738 
739 	joydev = kzalloc(sizeof(struct joydev), GFP_KERNEL);
740 	if (!joydev)
741 		return -ENOMEM;
742 
743 	INIT_LIST_HEAD(&joydev->client_list);
744 	spin_lock_init(&joydev->client_lock);
745 	mutex_init(&joydev->mutex);
746 	init_waitqueue_head(&joydev->wait);
747 
748 	snprintf(joydev->name, sizeof(joydev->name), "js%d", minor);
749 	joydev->exist = 1;
750 	joydev->minor = minor;
751 
752 	joydev->exist = 1;
753 	joydev->handle.dev = input_get_device(dev);
754 	joydev->handle.name = joydev->name;
755 	joydev->handle.handler = handler;
756 	joydev->handle.private = joydev;
757 
758 	for (i = 0; i < ABS_MAX + 1; i++)
759 		if (test_bit(i, dev->absbit)) {
760 			joydev->absmap[i] = joydev->nabs;
761 			joydev->abspam[joydev->nabs] = i;
762 			joydev->nabs++;
763 		}
764 
765 	for (i = BTN_JOYSTICK - BTN_MISC; i < KEY_MAX - BTN_MISC + 1; i++)
766 		if (test_bit(i + BTN_MISC, dev->keybit)) {
767 			joydev->keymap[i] = joydev->nkey;
768 			joydev->keypam[joydev->nkey] = i + BTN_MISC;
769 			joydev->nkey++;
770 		}
771 
772 	for (i = 0; i < BTN_JOYSTICK - BTN_MISC; i++)
773 		if (test_bit(i + BTN_MISC, dev->keybit)) {
774 			joydev->keymap[i] = joydev->nkey;
775 			joydev->keypam[joydev->nkey] = i + BTN_MISC;
776 			joydev->nkey++;
777 		}
778 
779 	for (i = 0; i < joydev->nabs; i++) {
780 		j = joydev->abspam[i];
781 		if (dev->absmax[j] == dev->absmin[j]) {
782 			joydev->corr[i].type = JS_CORR_NONE;
783 			joydev->abs[i] = dev->abs[j];
784 			continue;
785 		}
786 		joydev->corr[i].type = JS_CORR_BROKEN;
787 		joydev->corr[i].prec = dev->absfuzz[j];
788 		joydev->corr[i].coef[0] =
789 			(dev->absmax[j] + dev->absmin[j]) / 2 - dev->absflat[j];
790 		joydev->corr[i].coef[1] =
791 			(dev->absmax[j] + dev->absmin[j]) / 2 + dev->absflat[j];
792 
793 		t = (dev->absmax[j] - dev->absmin[j]) / 2 - 2 * dev->absflat[j];
794 		if (t) {
795 			joydev->corr[i].coef[2] = (1 << 29) / t;
796 			joydev->corr[i].coef[3] = (1 << 29) / t;
797 
798 			joydev->abs[i] = joydev_correct(dev->abs[j],
799 							joydev->corr + i);
800 		}
801 	}
802 
803 	dev_set_name(&joydev->dev, joydev->name);
804 	joydev->dev.devt = MKDEV(INPUT_MAJOR, JOYDEV_MINOR_BASE + minor);
805 	joydev->dev.class = &input_class;
806 	joydev->dev.parent = &dev->dev;
807 	joydev->dev.release = joydev_free;
808 	device_initialize(&joydev->dev);
809 
810 	error = input_register_handle(&joydev->handle);
811 	if (error)
812 		goto err_free_joydev;
813 
814 	error = joydev_install_chrdev(joydev);
815 	if (error)
816 		goto err_unregister_handle;
817 
818 	error = device_add(&joydev->dev);
819 	if (error)
820 		goto err_cleanup_joydev;
821 
822 	return 0;
823 
824  err_cleanup_joydev:
825 	joydev_cleanup(joydev);
826  err_unregister_handle:
827 	input_unregister_handle(&joydev->handle);
828  err_free_joydev:
829 	put_device(&joydev->dev);
830 	return error;
831 }
832 
joydev_disconnect(struct input_handle * handle)833 static void joydev_disconnect(struct input_handle *handle)
834 {
835 	struct joydev *joydev = handle->private;
836 
837 	device_del(&joydev->dev);
838 	joydev_cleanup(joydev);
839 	input_unregister_handle(handle);
840 	put_device(&joydev->dev);
841 }
842 
843 static const struct input_device_id joydev_blacklist[] = {
844 	{
845 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
846 				INPUT_DEVICE_ID_MATCH_KEYBIT,
847 		.evbit = { BIT_MASK(EV_KEY) },
848 		.keybit = { [BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH) },
849 	},	/* Avoid itouchpads, touchscreens and tablets */
850 	{ }	/* Terminating entry */
851 };
852 
853 static const struct input_device_id joydev_ids[] = {
854 	{
855 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
856 				INPUT_DEVICE_ID_MATCH_ABSBIT,
857 		.evbit = { BIT_MASK(EV_ABS) },
858 		.absbit = { BIT_MASK(ABS_X) },
859 	},
860 	{
861 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
862 				INPUT_DEVICE_ID_MATCH_ABSBIT,
863 		.evbit = { BIT_MASK(EV_ABS) },
864 		.absbit = { BIT_MASK(ABS_WHEEL) },
865 	},
866 	{
867 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
868 				INPUT_DEVICE_ID_MATCH_ABSBIT,
869 		.evbit = { BIT_MASK(EV_ABS) },
870 		.absbit = { BIT_MASK(ABS_THROTTLE) },
871 	},
872 	{ }	/* Terminating entry */
873 };
874 
875 MODULE_DEVICE_TABLE(input, joydev_ids);
876 
877 static struct input_handler joydev_handler = {
878 	.event		= joydev_event,
879 	.connect	= joydev_connect,
880 	.disconnect	= joydev_disconnect,
881 	.fops		= &joydev_fops,
882 	.minor		= JOYDEV_MINOR_BASE,
883 	.name		= "joydev",
884 	.id_table	= joydev_ids,
885 	.blacklist	= joydev_blacklist,
886 };
887 
joydev_init(void)888 static int __init joydev_init(void)
889 {
890 	return input_register_handler(&joydev_handler);
891 }
892 
joydev_exit(void)893 static void __exit joydev_exit(void)
894 {
895 	input_unregister_handler(&joydev_handler);
896 }
897 
898 module_init(joydev_init);
899 module_exit(joydev_exit);
900