Version:  2.0.40 2.2.26 2.4.37 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1

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/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 = kmalloc(len, GFP_KERNEL);
448         if (!abspam)
449                 return -ENOMEM;
450 
451         if (copy_from_user(abspam, argp, len)) {
452                 retval = -EFAULT;
453                 goto out;
454         }
455 
456         for (i = 0; i < joydev->nabs; i++) {
457                 if (abspam[i] > ABS_MAX) {
458                         retval = -EINVAL;
459                         goto out;
460                 }
461         }
462 
463         memcpy(joydev->abspam, abspam, len);
464 
465         for (i = 0; i < joydev->nabs; i++)
466                 joydev->absmap[joydev->abspam[i]] = i;
467 
468  out:
469         kfree(abspam);
470         return retval;
471 }
472 
473 static int joydev_handle_JSIOCSBTNMAP(struct joydev *joydev,
474                                       void __user *argp, size_t len)
475 {
476         __u16 *keypam;
477         int i;
478         int retval = 0;
479 
480         len = min(len, sizeof(joydev->keypam));
481 
482         /* Validate the map. */
483         keypam = kmalloc(len, GFP_KERNEL);
484         if (!keypam)
485                 return -ENOMEM;
486 
487         if (copy_from_user(keypam, argp, len)) {
488                 retval = -EFAULT;
489                 goto out;
490         }
491 
492         for (i = 0; i < joydev->nkey; i++) {
493                 if (keypam[i] > KEY_MAX || keypam[i] < BTN_MISC) {
494                         retval = -EINVAL;
495                         goto out;
496                 }
497         }
498 
499         memcpy(joydev->keypam, keypam, len);
500 
501         for (i = 0; i < joydev->nkey; i++)
502                 joydev->keymap[keypam[i] - BTN_MISC] = i;
503 
504  out:
505         kfree(keypam);
506         return retval;
507 }
508 
509 
510 static int joydev_ioctl_common(struct joydev *joydev,
511                                 unsigned int cmd, void __user *argp)
512 {
513         struct input_dev *dev = joydev->handle.dev;
514         size_t len;
515         int i;
516         const char *name;
517 
518         /* Process fixed-sized commands. */
519         switch (cmd) {
520 
521         case JS_SET_CAL:
522                 return copy_from_user(&joydev->glue.JS_CORR, argp,
523                                 sizeof(joydev->glue.JS_CORR)) ? -EFAULT : 0;
524 
525         case JS_GET_CAL:
526                 return copy_to_user(argp, &joydev->glue.JS_CORR,
527                                 sizeof(joydev->glue.JS_CORR)) ? -EFAULT : 0;
528 
529         case JS_SET_TIMEOUT:
530                 return get_user(joydev->glue.JS_TIMEOUT, (s32 __user *) argp);
531 
532         case JS_GET_TIMEOUT:
533                 return put_user(joydev->glue.JS_TIMEOUT, (s32 __user *) argp);
534 
535         case JSIOCGVERSION:
536                 return put_user(JS_VERSION, (__u32 __user *) argp);
537 
538         case JSIOCGAXES:
539                 return put_user(joydev->nabs, (__u8 __user *) argp);
540 
541         case JSIOCGBUTTONS:
542                 return put_user(joydev->nkey, (__u8 __user *) argp);
543 
544         case JSIOCSCORR:
545                 if (copy_from_user(joydev->corr, argp,
546                               sizeof(joydev->corr[0]) * joydev->nabs))
547                         return -EFAULT;
548 
549                 for (i = 0; i < joydev->nabs; i++) {
550                         int val = input_abs_get_val(dev, joydev->abspam[i]);
551                         joydev->abs[i] = joydev_correct(val, &joydev->corr[i]);
552                 }
553                 return 0;
554 
555         case JSIOCGCORR:
556                 return copy_to_user(argp, joydev->corr,
557                         sizeof(joydev->corr[0]) * joydev->nabs) ? -EFAULT : 0;
558 
559         }
560 
561         /*
562          * Process variable-sized commands (the axis and button map commands
563          * are considered variable-sized to decouple them from the values of
564          * ABS_MAX and KEY_MAX).
565          */
566         switch (cmd & ~IOCSIZE_MASK) {
567 
568         case (JSIOCSAXMAP & ~IOCSIZE_MASK):
569                 return joydev_handle_JSIOCSAXMAP(joydev, argp, _IOC_SIZE(cmd));
570 
571         case (JSIOCGAXMAP & ~IOCSIZE_MASK):
572                 len = min_t(size_t, _IOC_SIZE(cmd), sizeof(joydev->abspam));
573                 return copy_to_user(argp, joydev->abspam, len) ? -EFAULT : len;
574 
575         case (JSIOCSBTNMAP & ~IOCSIZE_MASK):
576                 return joydev_handle_JSIOCSBTNMAP(joydev, argp, _IOC_SIZE(cmd));
577 
578         case (JSIOCGBTNMAP & ~IOCSIZE_MASK):
579                 len = min_t(size_t, _IOC_SIZE(cmd), sizeof(joydev->keypam));
580                 return copy_to_user(argp, joydev->keypam, len) ? -EFAULT : len;
581 
582         case JSIOCGNAME(0):
583                 name = dev->name;
584                 if (!name)
585                         return 0;
586 
587                 len = min_t(size_t, _IOC_SIZE(cmd), strlen(name) + 1);
588                 return copy_to_user(argp, name, len) ? -EFAULT : len;
589         }
590 
591         return -EINVAL;
592 }
593 
594 #ifdef CONFIG_COMPAT
595 static long joydev_compat_ioctl(struct file *file,
596                                 unsigned int cmd, unsigned long arg)
597 {
598         struct joydev_client *client = file->private_data;
599         struct joydev *joydev = client->joydev;
600         void __user *argp = (void __user *)arg;
601         s32 tmp32;
602         struct JS_DATA_SAVE_TYPE_32 ds32;
603         int retval;
604 
605         retval = mutex_lock_interruptible(&joydev->mutex);
606         if (retval)
607                 return retval;
608 
609         if (!joydev->exist) {
610                 retval = -ENODEV;
611                 goto out;
612         }
613 
614         switch (cmd) {
615 
616         case JS_SET_TIMELIMIT:
617                 retval = get_user(tmp32, (s32 __user *) arg);
618                 if (retval == 0)
619                         joydev->glue.JS_TIMELIMIT = tmp32;
620                 break;
621 
622         case JS_GET_TIMELIMIT:
623                 tmp32 = joydev->glue.JS_TIMELIMIT;
624                 retval = put_user(tmp32, (s32 __user *) arg);
625                 break;
626 
627         case JS_SET_ALL:
628                 retval = copy_from_user(&ds32, argp,
629                                         sizeof(ds32)) ? -EFAULT : 0;
630                 if (retval == 0) {
631                         joydev->glue.JS_TIMEOUT    = ds32.JS_TIMEOUT;
632                         joydev->glue.BUSY          = ds32.BUSY;
633                         joydev->glue.JS_EXPIRETIME = ds32.JS_EXPIRETIME;
634                         joydev->glue.JS_TIMELIMIT  = ds32.JS_TIMELIMIT;
635                         joydev->glue.JS_SAVE       = ds32.JS_SAVE;
636                         joydev->glue.JS_CORR       = ds32.JS_CORR;
637                 }
638                 break;
639 
640         case JS_GET_ALL:
641                 ds32.JS_TIMEOUT    = joydev->glue.JS_TIMEOUT;
642                 ds32.BUSY          = joydev->glue.BUSY;
643                 ds32.JS_EXPIRETIME = joydev->glue.JS_EXPIRETIME;
644                 ds32.JS_TIMELIMIT  = joydev->glue.JS_TIMELIMIT;
645                 ds32.JS_SAVE       = joydev->glue.JS_SAVE;
646                 ds32.JS_CORR       = joydev->glue.JS_CORR;
647 
648                 retval = copy_to_user(argp, &ds32, sizeof(ds32)) ? -EFAULT : 0;
649                 break;
650 
651         default:
652                 retval = joydev_ioctl_common(joydev, cmd, argp);
653                 break;
654         }
655 
656  out:
657         mutex_unlock(&joydev->mutex);
658         return retval;
659 }
660 #endif /* CONFIG_COMPAT */
661 
662 static long joydev_ioctl(struct file *file,
663                          unsigned int cmd, unsigned long arg)
664 {
665         struct joydev_client *client = file->private_data;
666         struct joydev *joydev = client->joydev;
667         void __user *argp = (void __user *)arg;
668         int retval;
669 
670         retval = mutex_lock_interruptible(&joydev->mutex);
671         if (retval)
672                 return retval;
673 
674         if (!joydev->exist) {
675                 retval = -ENODEV;
676                 goto out;
677         }
678 
679         switch (cmd) {
680 
681         case JS_SET_TIMELIMIT:
682                 retval = get_user(joydev->glue.JS_TIMELIMIT,
683                                   (long __user *) arg);
684                 break;
685 
686         case JS_GET_TIMELIMIT:
687                 retval = put_user(joydev->glue.JS_TIMELIMIT,
688                                   (long __user *) arg);
689                 break;
690 
691         case JS_SET_ALL:
692                 retval = copy_from_user(&joydev->glue, argp,
693                                         sizeof(joydev->glue)) ? -EFAULT : 0;
694                 break;
695 
696         case JS_GET_ALL:
697                 retval = copy_to_user(argp, &joydev->glue,
698                                       sizeof(joydev->glue)) ? -EFAULT : 0;
699                 break;
700 
701         default:
702                 retval = joydev_ioctl_common(joydev, cmd, argp);
703                 break;
704         }
705  out:
706         mutex_unlock(&joydev->mutex);
707         return retval;
708 }
709 
710 static const struct file_operations joydev_fops = {
711         .owner          = THIS_MODULE,
712         .read           = joydev_read,
713         .poll           = joydev_poll,
714         .open           = joydev_open,
715         .release        = joydev_release,
716         .unlocked_ioctl = joydev_ioctl,
717 #ifdef CONFIG_COMPAT
718         .compat_ioctl   = joydev_compat_ioctl,
719 #endif
720         .fasync         = joydev_fasync,
721         .llseek         = no_llseek,
722 };
723 
724 /*
725  * Mark device non-existent. This disables writes, ioctls and
726  * prevents new users from opening the device. Already posted
727  * blocking reads will stay, however new ones will fail.
728  */
729 static void joydev_mark_dead(struct joydev *joydev)
730 {
731         mutex_lock(&joydev->mutex);
732         joydev->exist = false;
733         mutex_unlock(&joydev->mutex);
734 }
735 
736 static void joydev_cleanup(struct joydev *joydev)
737 {
738         struct input_handle *handle = &joydev->handle;
739 
740         joydev_mark_dead(joydev);
741         joydev_hangup(joydev);
742 
743         cdev_del(&joydev->cdev);
744 
745         /* joydev is marked dead so no one else accesses joydev->open */
746         if (joydev->open)
747                 input_close_device(handle);
748 }
749 
750 static bool joydev_dev_is_absolute_mouse(struct input_dev *dev)
751 {
752         DECLARE_BITMAP(jd_scratch, KEY_CNT);
753 
754         BUILD_BUG_ON(ABS_CNT > KEY_CNT || EV_CNT > KEY_CNT);
755 
756         /*
757          * Virtualization (VMware, etc) and remote management (HP
758          * ILO2) solutions use absolute coordinates for their virtual
759          * pointing devices so that there is one-to-one relationship
760          * between pointer position on the host screen and virtual
761          * guest screen, and so their mice use ABS_X, ABS_Y and 3
762          * primary button events. This clashes with what joydev
763          * considers to be joysticks (a device with at minimum ABS_X
764          * axis).
765          *
766          * Here we are trying to separate absolute mice from
767          * joysticks. A device is, for joystick detection purposes,
768          * considered to be an absolute mouse if the following is
769          * true:
770          *
771          * 1) Event types are exactly EV_ABS, EV_KEY and EV_SYN.
772          * 2) Absolute events are exactly ABS_X and ABS_Y.
773          * 3) Keys are exactly BTN_LEFT, BTN_RIGHT and BTN_MIDDLE.
774          * 4) Device is not on "Amiga" bus.
775          */
776 
777         bitmap_zero(jd_scratch, EV_CNT);
778         __set_bit(EV_ABS, jd_scratch);
779         __set_bit(EV_KEY, jd_scratch);
780         __set_bit(EV_SYN, jd_scratch);
781         if (!bitmap_equal(jd_scratch, dev->evbit, EV_CNT))
782                 return false;
783 
784         bitmap_zero(jd_scratch, ABS_CNT);
785         __set_bit(ABS_X, jd_scratch);
786         __set_bit(ABS_Y, jd_scratch);
787         if (!bitmap_equal(dev->absbit, jd_scratch, ABS_CNT))
788                 return false;
789 
790         bitmap_zero(jd_scratch, KEY_CNT);
791         __set_bit(BTN_LEFT, jd_scratch);
792         __set_bit(BTN_RIGHT, jd_scratch);
793         __set_bit(BTN_MIDDLE, jd_scratch);
794 
795         if (!bitmap_equal(dev->keybit, jd_scratch, KEY_CNT))
796                 return false;
797 
798         /*
799          * Amiga joystick (amijoy) historically uses left/middle/right
800          * button events.
801          */
802         if (dev->id.bustype == BUS_AMIGA)
803                 return false;
804 
805         return true;
806 }
807 
808 static bool joydev_match(struct input_handler *handler, struct input_dev *dev)
809 {
810         /* Avoid touchpads and touchscreens */
811         if (test_bit(EV_KEY, dev->evbit) && test_bit(BTN_TOUCH, dev->keybit))
812                 return false;
813 
814         /* Avoid tablets, digitisers and similar devices */
815         if (test_bit(EV_KEY, dev->evbit) && test_bit(BTN_DIGI, dev->keybit))
816                 return false;
817 
818         /* Avoid absolute mice */
819         if (joydev_dev_is_absolute_mouse(dev))
820                 return false;
821 
822         return true;
823 }
824 
825 static int joydev_connect(struct input_handler *handler, struct input_dev *dev,
826                           const struct input_device_id *id)
827 {
828         struct joydev *joydev;
829         int i, j, t, minor, dev_no;
830         int error;
831 
832         minor = input_get_new_minor(JOYDEV_MINOR_BASE, JOYDEV_MINORS, true);
833         if (minor < 0) {
834                 error = minor;
835                 pr_err("failed to reserve new minor: %d\n", error);
836                 return error;
837         }
838 
839         joydev = kzalloc(sizeof(struct joydev), GFP_KERNEL);
840         if (!joydev) {
841                 error = -ENOMEM;
842                 goto err_free_minor;
843         }
844 
845         INIT_LIST_HEAD(&joydev->client_list);
846         spin_lock_init(&joydev->client_lock);
847         mutex_init(&joydev->mutex);
848         init_waitqueue_head(&joydev->wait);
849         joydev->exist = true;
850 
851         dev_no = minor;
852         /* Normalize device number if it falls into legacy range */
853         if (dev_no < JOYDEV_MINOR_BASE + JOYDEV_MINORS)
854                 dev_no -= JOYDEV_MINOR_BASE;
855         dev_set_name(&joydev->dev, "js%d", dev_no);
856 
857         joydev->handle.dev = input_get_device(dev);
858         joydev->handle.name = dev_name(&joydev->dev);
859         joydev->handle.handler = handler;
860         joydev->handle.private = joydev;
861 
862         for (i = 0; i < ABS_CNT; i++)
863                 if (test_bit(i, dev->absbit)) {
864                         joydev->absmap[i] = joydev->nabs;
865                         joydev->abspam[joydev->nabs] = i;
866                         joydev->nabs++;
867                 }
868 
869         for (i = BTN_JOYSTICK - BTN_MISC; i < KEY_MAX - BTN_MISC + 1; i++)
870                 if (test_bit(i + BTN_MISC, dev->keybit)) {
871                         joydev->keymap[i] = joydev->nkey;
872                         joydev->keypam[joydev->nkey] = i + BTN_MISC;
873                         joydev->nkey++;
874                 }
875 
876         for (i = 0; i < BTN_JOYSTICK - BTN_MISC; i++)
877                 if (test_bit(i + BTN_MISC, dev->keybit)) {
878                         joydev->keymap[i] = joydev->nkey;
879                         joydev->keypam[joydev->nkey] = i + BTN_MISC;
880                         joydev->nkey++;
881                 }
882 
883         for (i = 0; i < joydev->nabs; i++) {
884                 j = joydev->abspam[i];
885                 if (input_abs_get_max(dev, j) == input_abs_get_min(dev, j)) {
886                         joydev->corr[i].type = JS_CORR_NONE;
887                         joydev->abs[i] = input_abs_get_val(dev, j);
888                         continue;
889                 }
890                 joydev->corr[i].type = JS_CORR_BROKEN;
891                 joydev->corr[i].prec = input_abs_get_fuzz(dev, j);
892 
893                 t = (input_abs_get_max(dev, j) + input_abs_get_min(dev, j)) / 2;
894                 joydev->corr[i].coef[0] = t - input_abs_get_flat(dev, j);
895                 joydev->corr[i].coef[1] = t + input_abs_get_flat(dev, j);
896 
897                 t = (input_abs_get_max(dev, j) - input_abs_get_min(dev, j)) / 2
898                         - 2 * input_abs_get_flat(dev, j);
899                 if (t) {
900                         joydev->corr[i].coef[2] = (1 << 29) / t;
901                         joydev->corr[i].coef[3] = (1 << 29) / t;
902 
903                         joydev->abs[i] =
904                                 joydev_correct(input_abs_get_val(dev, j),
905                                                joydev->corr + i);
906                 }
907         }
908 
909         joydev->dev.devt = MKDEV(INPUT_MAJOR, minor);
910         joydev->dev.class = &input_class;
911         joydev->dev.parent = &dev->dev;
912         joydev->dev.release = joydev_free;
913         device_initialize(&joydev->dev);
914 
915         error = input_register_handle(&joydev->handle);
916         if (error)
917                 goto err_free_joydev;
918 
919         cdev_init(&joydev->cdev, &joydev_fops);
920         joydev->cdev.kobj.parent = &joydev->dev.kobj;
921         error = cdev_add(&joydev->cdev, joydev->dev.devt, 1);
922         if (error)
923                 goto err_unregister_handle;
924 
925         error = device_add(&joydev->dev);
926         if (error)
927                 goto err_cleanup_joydev;
928 
929         return 0;
930 
931  err_cleanup_joydev:
932         joydev_cleanup(joydev);
933  err_unregister_handle:
934         input_unregister_handle(&joydev->handle);
935  err_free_joydev:
936         put_device(&joydev->dev);
937  err_free_minor:
938         input_free_minor(minor);
939         return error;
940 }
941 
942 static void joydev_disconnect(struct input_handle *handle)
943 {
944         struct joydev *joydev = handle->private;
945 
946         device_del(&joydev->dev);
947         joydev_cleanup(joydev);
948         input_free_minor(MINOR(joydev->dev.devt));
949         input_unregister_handle(handle);
950         put_device(&joydev->dev);
951 }
952 
953 static const struct input_device_id joydev_ids[] = {
954         {
955                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
956                                 INPUT_DEVICE_ID_MATCH_ABSBIT,
957                 .evbit = { BIT_MASK(EV_ABS) },
958                 .absbit = { BIT_MASK(ABS_X) },
959         },
960         {
961                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
962                                 INPUT_DEVICE_ID_MATCH_ABSBIT,
963                 .evbit = { BIT_MASK(EV_ABS) },
964                 .absbit = { BIT_MASK(ABS_WHEEL) },
965         },
966         {
967                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
968                                 INPUT_DEVICE_ID_MATCH_ABSBIT,
969                 .evbit = { BIT_MASK(EV_ABS) },
970                 .absbit = { BIT_MASK(ABS_THROTTLE) },
971         },
972         {
973                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
974                                 INPUT_DEVICE_ID_MATCH_KEYBIT,
975                 .evbit = { BIT_MASK(EV_KEY) },
976                 .keybit = {[BIT_WORD(BTN_JOYSTICK)] = BIT_MASK(BTN_JOYSTICK) },
977         },
978         {
979                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
980                                 INPUT_DEVICE_ID_MATCH_KEYBIT,
981                 .evbit = { BIT_MASK(EV_KEY) },
982                 .keybit = { [BIT_WORD(BTN_GAMEPAD)] = BIT_MASK(BTN_GAMEPAD) },
983         },
984         {
985                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
986                                 INPUT_DEVICE_ID_MATCH_KEYBIT,
987                 .evbit = { BIT_MASK(EV_KEY) },
988                 .keybit = { [BIT_WORD(BTN_TRIGGER_HAPPY)] = BIT_MASK(BTN_TRIGGER_HAPPY) },
989         },
990         { }     /* Terminating entry */
991 };
992 
993 MODULE_DEVICE_TABLE(input, joydev_ids);
994 
995 static struct input_handler joydev_handler = {
996         .event          = joydev_event,
997         .match          = joydev_match,
998         .connect        = joydev_connect,
999         .disconnect     = joydev_disconnect,
1000         .legacy_minors  = true,
1001         .minor          = JOYDEV_MINOR_BASE,
1002         .name           = "joydev",
1003         .id_table       = joydev_ids,
1004 };
1005 
1006 static int __init joydev_init(void)
1007 {
1008         return input_register_handler(&joydev_handler);
1009 }
1010 
1011 static void __exit joydev_exit(void)
1012 {
1013         input_unregister_handler(&joydev_handler);
1014 }
1015 
1016 module_init(joydev_init);
1017 module_exit(joydev_exit);
1018 

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