GNU Linux-libre 4.9.328-gnu1
[releases.git] / drivers / input / joydev.c
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
32 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
33 MODULE_DESCRIPTION("Joystick device interfaces");
34 MODULE_SUPPORTED_DEVICE("input/js");
35 MODULE_LICENSE("GPL");
36
37 #define JOYDEV_MINOR_BASE       0
38 #define JOYDEV_MINORS           16
39 #define JOYDEV_BUFFER_SIZE      64
40
41 struct joydev {
42         int open;
43         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
63 struct joydev_client {
64         struct js_event buffer[JOYDEV_BUFFER_SIZE];
65         int head;
66         int tail;
67         int startup;
68         spinlock_t buffer_lock; /* protects access to buffer, head and tail */
69         struct fasync_struct *fasync;
70         struct joydev *joydev;
71         struct list_head node;
72 };
73
74 static 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
94 static 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
118 static 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
159 static 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
166 static 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
174 static 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
182 static 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
191 static 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
211 static 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  */
225 static 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
237 static 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
250 static 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
280 static 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
312 static 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  */
333 static 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
368 static 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
376 static 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 */
427 static 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
437 static 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 = memdup_user(argp, len);
448         if (IS_ERR(abspam))
449                 return PTR_ERR(abspam);
450
451         for (i = 0; i < len && i < joydev->nabs; i++) {
452                 if (abspam[i] > ABS_MAX) {
453                         retval = -EINVAL;
454                         goto out;
455                 }
456         }
457
458         memcpy(joydev->abspam, abspam, len);
459
460         for (i = 0; i < joydev->nabs; i++)
461                 joydev->absmap[joydev->abspam[i]] = i;
462
463  out:
464         kfree(abspam);
465         return retval;
466 }
467
468 static int joydev_handle_JSIOCSBTNMAP(struct joydev *joydev,
469                                       void __user *argp, size_t len)
470 {
471         __u16 *keypam;
472         int i;
473         int retval = 0;
474
475         if (len % sizeof(*keypam))
476                 return -EINVAL;
477
478         len = min(len, sizeof(joydev->keypam));
479
480         /* Validate the map. */
481         keypam = memdup_user(argp, len);
482         if (IS_ERR(keypam))
483                 return PTR_ERR(keypam);
484
485         for (i = 0; i < (len / 2) && i < joydev->nkey; i++) {
486                 if (keypam[i] > KEY_MAX || keypam[i] < BTN_MISC) {
487                         retval = -EINVAL;
488                         goto out;
489                 }
490         }
491
492         memcpy(joydev->keypam, keypam, len);
493
494         for (i = 0; i < joydev->nkey; i++)
495                 joydev->keymap[joydev->keypam[i] - BTN_MISC] = i;
496
497  out:
498         kfree(keypam);
499         return retval;
500 }
501
502
503 static int joydev_ioctl_common(struct joydev *joydev,
504                                 unsigned int cmd, void __user *argp)
505 {
506         struct input_dev *dev = joydev->handle.dev;
507         size_t len;
508         int i;
509         const char *name;
510
511         /* Process fixed-sized commands. */
512         switch (cmd) {
513
514         case JS_SET_CAL:
515                 return copy_from_user(&joydev->glue.JS_CORR, argp,
516                                 sizeof(joydev->glue.JS_CORR)) ? -EFAULT : 0;
517
518         case JS_GET_CAL:
519                 return copy_to_user(argp, &joydev->glue.JS_CORR,
520                                 sizeof(joydev->glue.JS_CORR)) ? -EFAULT : 0;
521
522         case JS_SET_TIMEOUT:
523                 return get_user(joydev->glue.JS_TIMEOUT, (s32 __user *) argp);
524
525         case JS_GET_TIMEOUT:
526                 return put_user(joydev->glue.JS_TIMEOUT, (s32 __user *) argp);
527
528         case JSIOCGVERSION:
529                 return put_user(JS_VERSION, (__u32 __user *) argp);
530
531         case JSIOCGAXES:
532                 return put_user(joydev->nabs, (__u8 __user *) argp);
533
534         case JSIOCGBUTTONS:
535                 return put_user(joydev->nkey, (__u8 __user *) argp);
536
537         case JSIOCSCORR:
538                 if (copy_from_user(joydev->corr, argp,
539                               sizeof(joydev->corr[0]) * joydev->nabs))
540                         return -EFAULT;
541
542                 for (i = 0; i < joydev->nabs; i++) {
543                         int val = input_abs_get_val(dev, joydev->abspam[i]);
544                         joydev->abs[i] = joydev_correct(val, &joydev->corr[i]);
545                 }
546                 return 0;
547
548         case JSIOCGCORR:
549                 return copy_to_user(argp, joydev->corr,
550                         sizeof(joydev->corr[0]) * joydev->nabs) ? -EFAULT : 0;
551
552         }
553
554         /*
555          * Process variable-sized commands (the axis and button map commands
556          * are considered variable-sized to decouple them from the values of
557          * ABS_MAX and KEY_MAX).
558          */
559         switch (cmd & ~IOCSIZE_MASK) {
560
561         case (JSIOCSAXMAP & ~IOCSIZE_MASK):
562                 return joydev_handle_JSIOCSAXMAP(joydev, argp, _IOC_SIZE(cmd));
563
564         case (JSIOCGAXMAP & ~IOCSIZE_MASK):
565                 len = min_t(size_t, _IOC_SIZE(cmd), sizeof(joydev->abspam));
566                 return copy_to_user(argp, joydev->abspam, len) ? -EFAULT : len;
567
568         case (JSIOCSBTNMAP & ~IOCSIZE_MASK):
569                 return joydev_handle_JSIOCSBTNMAP(joydev, argp, _IOC_SIZE(cmd));
570
571         case (JSIOCGBTNMAP & ~IOCSIZE_MASK):
572                 len = min_t(size_t, _IOC_SIZE(cmd), sizeof(joydev->keypam));
573                 return copy_to_user(argp, joydev->keypam, len) ? -EFAULT : len;
574
575         case JSIOCGNAME(0):
576                 name = dev->name;
577                 if (!name)
578                         return 0;
579
580                 len = min_t(size_t, _IOC_SIZE(cmd), strlen(name) + 1);
581                 return copy_to_user(argp, name, len) ? -EFAULT : len;
582         }
583
584         return -EINVAL;
585 }
586
587 #ifdef CONFIG_COMPAT
588 static long joydev_compat_ioctl(struct file *file,
589                                 unsigned int cmd, unsigned long arg)
590 {
591         struct joydev_client *client = file->private_data;
592         struct joydev *joydev = client->joydev;
593         void __user *argp = (void __user *)arg;
594         s32 tmp32;
595         struct JS_DATA_SAVE_TYPE_32 ds32;
596         int retval;
597
598         retval = mutex_lock_interruptible(&joydev->mutex);
599         if (retval)
600                 return retval;
601
602         if (!joydev->exist) {
603                 retval = -ENODEV;
604                 goto out;
605         }
606
607         switch (cmd) {
608
609         case JS_SET_TIMELIMIT:
610                 retval = get_user(tmp32, (s32 __user *) arg);
611                 if (retval == 0)
612                         joydev->glue.JS_TIMELIMIT = tmp32;
613                 break;
614
615         case JS_GET_TIMELIMIT:
616                 tmp32 = joydev->glue.JS_TIMELIMIT;
617                 retval = put_user(tmp32, (s32 __user *) arg);
618                 break;
619
620         case JS_SET_ALL:
621                 retval = copy_from_user(&ds32, argp,
622                                         sizeof(ds32)) ? -EFAULT : 0;
623                 if (retval == 0) {
624                         joydev->glue.JS_TIMEOUT    = ds32.JS_TIMEOUT;
625                         joydev->glue.BUSY          = ds32.BUSY;
626                         joydev->glue.JS_EXPIRETIME = ds32.JS_EXPIRETIME;
627                         joydev->glue.JS_TIMELIMIT  = ds32.JS_TIMELIMIT;
628                         joydev->glue.JS_SAVE       = ds32.JS_SAVE;
629                         joydev->glue.JS_CORR       = ds32.JS_CORR;
630                 }
631                 break;
632
633         case JS_GET_ALL:
634                 ds32.JS_TIMEOUT    = joydev->glue.JS_TIMEOUT;
635                 ds32.BUSY          = joydev->glue.BUSY;
636                 ds32.JS_EXPIRETIME = joydev->glue.JS_EXPIRETIME;
637                 ds32.JS_TIMELIMIT  = joydev->glue.JS_TIMELIMIT;
638                 ds32.JS_SAVE       = joydev->glue.JS_SAVE;
639                 ds32.JS_CORR       = joydev->glue.JS_CORR;
640
641                 retval = copy_to_user(argp, &ds32, sizeof(ds32)) ? -EFAULT : 0;
642                 break;
643
644         default:
645                 retval = joydev_ioctl_common(joydev, cmd, argp);
646                 break;
647         }
648
649  out:
650         mutex_unlock(&joydev->mutex);
651         return retval;
652 }
653 #endif /* CONFIG_COMPAT */
654
655 static long joydev_ioctl(struct file *file,
656                          unsigned int cmd, unsigned long arg)
657 {
658         struct joydev_client *client = file->private_data;
659         struct joydev *joydev = client->joydev;
660         void __user *argp = (void __user *)arg;
661         int retval;
662
663         retval = mutex_lock_interruptible(&joydev->mutex);
664         if (retval)
665                 return retval;
666
667         if (!joydev->exist) {
668                 retval = -ENODEV;
669                 goto out;
670         }
671
672         switch (cmd) {
673
674         case JS_SET_TIMELIMIT:
675                 retval = get_user(joydev->glue.JS_TIMELIMIT,
676                                   (long __user *) arg);
677                 break;
678
679         case JS_GET_TIMELIMIT:
680                 retval = put_user(joydev->glue.JS_TIMELIMIT,
681                                   (long __user *) arg);
682                 break;
683
684         case JS_SET_ALL:
685                 retval = copy_from_user(&joydev->glue, argp,
686                                         sizeof(joydev->glue)) ? -EFAULT : 0;
687                 break;
688
689         case JS_GET_ALL:
690                 retval = copy_to_user(argp, &joydev->glue,
691                                       sizeof(joydev->glue)) ? -EFAULT : 0;
692                 break;
693
694         default:
695                 retval = joydev_ioctl_common(joydev, cmd, argp);
696                 break;
697         }
698  out:
699         mutex_unlock(&joydev->mutex);
700         return retval;
701 }
702
703 static const struct file_operations joydev_fops = {
704         .owner          = THIS_MODULE,
705         .read           = joydev_read,
706         .poll           = joydev_poll,
707         .open           = joydev_open,
708         .release        = joydev_release,
709         .unlocked_ioctl = joydev_ioctl,
710 #ifdef CONFIG_COMPAT
711         .compat_ioctl   = joydev_compat_ioctl,
712 #endif
713         .fasync         = joydev_fasync,
714         .llseek         = no_llseek,
715 };
716
717 /*
718  * Mark device non-existent. This disables writes, ioctls and
719  * prevents new users from opening the device. Already posted
720  * blocking reads will stay, however new ones will fail.
721  */
722 static void joydev_mark_dead(struct joydev *joydev)
723 {
724         mutex_lock(&joydev->mutex);
725         joydev->exist = false;
726         mutex_unlock(&joydev->mutex);
727 }
728
729 static void joydev_cleanup(struct joydev *joydev)
730 {
731         struct input_handle *handle = &joydev->handle;
732
733         joydev_mark_dead(joydev);
734         joydev_hangup(joydev);
735
736         cdev_del(&joydev->cdev);
737
738         /* joydev is marked dead so no one else accesses joydev->open */
739         if (joydev->open)
740                 input_close_device(handle);
741 }
742
743 static bool joydev_dev_is_absolute_mouse(struct input_dev *dev)
744 {
745         DECLARE_BITMAP(jd_scratch, KEY_CNT);
746
747         BUILD_BUG_ON(ABS_CNT > KEY_CNT || EV_CNT > KEY_CNT);
748
749         /*
750          * Virtualization (VMware, etc) and remote management (HP
751          * ILO2) solutions use absolute coordinates for their virtual
752          * pointing devices so that there is one-to-one relationship
753          * between pointer position on the host screen and virtual
754          * guest screen, and so their mice use ABS_X, ABS_Y and 3
755          * primary button events. This clashes with what joydev
756          * considers to be joysticks (a device with at minimum ABS_X
757          * axis).
758          *
759          * Here we are trying to separate absolute mice from
760          * joysticks. A device is, for joystick detection purposes,
761          * considered to be an absolute mouse if the following is
762          * true:
763          *
764          * 1) Event types are exactly EV_ABS, EV_KEY and EV_SYN.
765          * 2) Absolute events are exactly ABS_X and ABS_Y.
766          * 3) Keys are exactly BTN_LEFT, BTN_RIGHT and BTN_MIDDLE.
767          * 4) Device is not on "Amiga" bus.
768          */
769
770         bitmap_zero(jd_scratch, EV_CNT);
771         __set_bit(EV_ABS, jd_scratch);
772         __set_bit(EV_KEY, jd_scratch);
773         __set_bit(EV_SYN, jd_scratch);
774         if (!bitmap_equal(jd_scratch, dev->evbit, EV_CNT))
775                 return false;
776
777         bitmap_zero(jd_scratch, ABS_CNT);
778         __set_bit(ABS_X, jd_scratch);
779         __set_bit(ABS_Y, jd_scratch);
780         if (!bitmap_equal(dev->absbit, jd_scratch, ABS_CNT))
781                 return false;
782
783         bitmap_zero(jd_scratch, KEY_CNT);
784         __set_bit(BTN_LEFT, jd_scratch);
785         __set_bit(BTN_RIGHT, jd_scratch);
786         __set_bit(BTN_MIDDLE, jd_scratch);
787
788         if (!bitmap_equal(dev->keybit, jd_scratch, KEY_CNT))
789                 return false;
790
791         /*
792          * Amiga joystick (amijoy) historically uses left/middle/right
793          * button events.
794          */
795         if (dev->id.bustype == BUS_AMIGA)
796                 return false;
797
798         return true;
799 }
800
801 static bool joydev_match(struct input_handler *handler, struct input_dev *dev)
802 {
803         /* Avoid touchpads and touchscreens */
804         if (test_bit(EV_KEY, dev->evbit) && test_bit(BTN_TOUCH, dev->keybit))
805                 return false;
806
807         /* Avoid tablets, digitisers and similar devices */
808         if (test_bit(EV_KEY, dev->evbit) && test_bit(BTN_DIGI, dev->keybit))
809                 return false;
810
811         /* Avoid absolute mice */
812         if (joydev_dev_is_absolute_mouse(dev))
813                 return false;
814
815         return true;
816 }
817
818 static int joydev_connect(struct input_handler *handler, struct input_dev *dev,
819                           const struct input_device_id *id)
820 {
821         struct joydev *joydev;
822         int i, j, t, minor, dev_no;
823         int error;
824
825         minor = input_get_new_minor(JOYDEV_MINOR_BASE, JOYDEV_MINORS, true);
826         if (minor < 0) {
827                 error = minor;
828                 pr_err("failed to reserve new minor: %d\n", error);
829                 return error;
830         }
831
832         joydev = kzalloc(sizeof(struct joydev), GFP_KERNEL);
833         if (!joydev) {
834                 error = -ENOMEM;
835                 goto err_free_minor;
836         }
837
838         INIT_LIST_HEAD(&joydev->client_list);
839         spin_lock_init(&joydev->client_lock);
840         mutex_init(&joydev->mutex);
841         init_waitqueue_head(&joydev->wait);
842         joydev->exist = true;
843
844         dev_no = minor;
845         /* Normalize device number if it falls into legacy range */
846         if (dev_no < JOYDEV_MINOR_BASE + JOYDEV_MINORS)
847                 dev_no -= JOYDEV_MINOR_BASE;
848         dev_set_name(&joydev->dev, "js%d", dev_no);
849
850         joydev->handle.dev = input_get_device(dev);
851         joydev->handle.name = dev_name(&joydev->dev);
852         joydev->handle.handler = handler;
853         joydev->handle.private = joydev;
854
855         for_each_set_bit(i, dev->absbit, ABS_CNT) {
856                 joydev->absmap[i] = joydev->nabs;
857                 joydev->abspam[joydev->nabs] = i;
858                 joydev->nabs++;
859         }
860
861         for (i = BTN_JOYSTICK - BTN_MISC; i < KEY_MAX - BTN_MISC + 1; i++)
862                 if (test_bit(i + BTN_MISC, dev->keybit)) {
863                         joydev->keymap[i] = joydev->nkey;
864                         joydev->keypam[joydev->nkey] = i + BTN_MISC;
865                         joydev->nkey++;
866                 }
867
868         for (i = 0; i < BTN_JOYSTICK - BTN_MISC; i++)
869                 if (test_bit(i + BTN_MISC, dev->keybit)) {
870                         joydev->keymap[i] = joydev->nkey;
871                         joydev->keypam[joydev->nkey] = i + BTN_MISC;
872                         joydev->nkey++;
873                 }
874
875         for (i = 0; i < joydev->nabs; i++) {
876                 j = joydev->abspam[i];
877                 if (input_abs_get_max(dev, j) == input_abs_get_min(dev, j)) {
878                         joydev->corr[i].type = JS_CORR_NONE;
879                         joydev->abs[i] = input_abs_get_val(dev, j);
880                         continue;
881                 }
882                 joydev->corr[i].type = JS_CORR_BROKEN;
883                 joydev->corr[i].prec = input_abs_get_fuzz(dev, j);
884
885                 t = (input_abs_get_max(dev, j) + input_abs_get_min(dev, j)) / 2;
886                 joydev->corr[i].coef[0] = t - input_abs_get_flat(dev, j);
887                 joydev->corr[i].coef[1] = t + input_abs_get_flat(dev, j);
888
889                 t = (input_abs_get_max(dev, j) - input_abs_get_min(dev, j)) / 2
890                         - 2 * input_abs_get_flat(dev, j);
891                 if (t) {
892                         joydev->corr[i].coef[2] = (1 << 29) / t;
893                         joydev->corr[i].coef[3] = (1 << 29) / t;
894
895                         joydev->abs[i] =
896                                 joydev_correct(input_abs_get_val(dev, j),
897                                                joydev->corr + i);
898                 }
899         }
900
901         joydev->dev.devt = MKDEV(INPUT_MAJOR, minor);
902         joydev->dev.class = &input_class;
903         joydev->dev.parent = &dev->dev;
904         joydev->dev.release = joydev_free;
905         device_initialize(&joydev->dev);
906
907         error = input_register_handle(&joydev->handle);
908         if (error)
909                 goto err_free_joydev;
910
911         cdev_init(&joydev->cdev, &joydev_fops);
912         joydev->cdev.kobj.parent = &joydev->dev.kobj;
913         error = cdev_add(&joydev->cdev, joydev->dev.devt, 1);
914         if (error)
915                 goto err_unregister_handle;
916
917         error = device_add(&joydev->dev);
918         if (error)
919                 goto err_cleanup_joydev;
920
921         return 0;
922
923  err_cleanup_joydev:
924         joydev_cleanup(joydev);
925  err_unregister_handle:
926         input_unregister_handle(&joydev->handle);
927  err_free_joydev:
928         put_device(&joydev->dev);
929  err_free_minor:
930         input_free_minor(minor);
931         return error;
932 }
933
934 static void joydev_disconnect(struct input_handle *handle)
935 {
936         struct joydev *joydev = handle->private;
937
938         device_del(&joydev->dev);
939         joydev_cleanup(joydev);
940         input_free_minor(MINOR(joydev->dev.devt));
941         input_unregister_handle(handle);
942         put_device(&joydev->dev);
943 }
944
945 static const struct input_device_id joydev_ids[] = {
946         {
947                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
948                                 INPUT_DEVICE_ID_MATCH_ABSBIT,
949                 .evbit = { BIT_MASK(EV_ABS) },
950                 .absbit = { BIT_MASK(ABS_X) },
951         },
952         {
953                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
954                                 INPUT_DEVICE_ID_MATCH_ABSBIT,
955                 .evbit = { BIT_MASK(EV_ABS) },
956                 .absbit = { BIT_MASK(ABS_Z) },
957         },
958         {
959                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
960                                 INPUT_DEVICE_ID_MATCH_ABSBIT,
961                 .evbit = { BIT_MASK(EV_ABS) },
962                 .absbit = { BIT_MASK(ABS_WHEEL) },
963         },
964         {
965                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
966                                 INPUT_DEVICE_ID_MATCH_ABSBIT,
967                 .evbit = { BIT_MASK(EV_ABS) },
968                 .absbit = { BIT_MASK(ABS_THROTTLE) },
969         },
970         {
971                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
972                                 INPUT_DEVICE_ID_MATCH_KEYBIT,
973                 .evbit = { BIT_MASK(EV_KEY) },
974                 .keybit = {[BIT_WORD(BTN_JOYSTICK)] = BIT_MASK(BTN_JOYSTICK) },
975         },
976         {
977                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
978                                 INPUT_DEVICE_ID_MATCH_KEYBIT,
979                 .evbit = { BIT_MASK(EV_KEY) },
980                 .keybit = { [BIT_WORD(BTN_GAMEPAD)] = BIT_MASK(BTN_GAMEPAD) },
981         },
982         {
983                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
984                                 INPUT_DEVICE_ID_MATCH_KEYBIT,
985                 .evbit = { BIT_MASK(EV_KEY) },
986                 .keybit = { [BIT_WORD(BTN_TRIGGER_HAPPY)] = BIT_MASK(BTN_TRIGGER_HAPPY) },
987         },
988         { }     /* Terminating entry */
989 };
990
991 MODULE_DEVICE_TABLE(input, joydev_ids);
992
993 static struct input_handler joydev_handler = {
994         .event          = joydev_event,
995         .match          = joydev_match,
996         .connect        = joydev_connect,
997         .disconnect     = joydev_disconnect,
998         .legacy_minors  = true,
999         .minor          = JOYDEV_MINOR_BASE,
1000         .name           = "joydev",
1001         .id_table       = joydev_ids,
1002 };
1003
1004 static int __init joydev_init(void)
1005 {
1006         return input_register_handler(&joydev_handler);
1007 }
1008
1009 static void __exit joydev_exit(void)
1010 {
1011         input_unregister_handler(&joydev_handler);
1012 }
1013
1014 module_init(joydev_init);
1015 module_exit(joydev_exit);