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