Version:  2.0.40 2.2.26 2.4.37 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 4.10

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

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