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