[PATCH] Add include/linux/freezer.h and move definitions from sched.h
[linux-2.6.git] / drivers / input / gameport / gameport.c
1 /*
2  * Generic gameport layer
3  *
4  * Copyright (c) 1999-2002 Vojtech Pavlik
5  * Copyright (c) 2005 Dmitry Torokhov
6  */
7
8 /*
9  * This program is free software; you can redistribute it and/or modify it
10  * under the terms of the GNU General Public License version 2 as published by
11  * the Free Software Foundation.
12  */
13
14 #include <linux/stddef.h>
15 #include <linux/module.h>
16 #include <linux/ioport.h>
17 #include <linux/init.h>
18 #include <linux/gameport.h>
19 #include <linux/wait.h>
20 #include <linux/sched.h>
21 #include <linux/slab.h>
22 #include <linux/delay.h>
23 #include <linux/kthread.h>
24 #include <linux/sched.h>        /* HZ */
25 #include <linux/mutex.h>
26 #include <linux/freezer.h>
27
28 /*#include <asm/io.h>*/
29
30 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
31 MODULE_DESCRIPTION("Generic gameport layer");
32 MODULE_LICENSE("GPL");
33
34 EXPORT_SYMBOL(__gameport_register_port);
35 EXPORT_SYMBOL(gameport_unregister_port);
36 EXPORT_SYMBOL(__gameport_register_driver);
37 EXPORT_SYMBOL(gameport_unregister_driver);
38 EXPORT_SYMBOL(gameport_open);
39 EXPORT_SYMBOL(gameport_close);
40 EXPORT_SYMBOL(gameport_rescan);
41 EXPORT_SYMBOL(gameport_cooked_read);
42 EXPORT_SYMBOL(gameport_set_name);
43 EXPORT_SYMBOL(gameport_set_phys);
44 EXPORT_SYMBOL(gameport_start_polling);
45 EXPORT_SYMBOL(gameport_stop_polling);
46
47 /*
48  * gameport_mutex protects entire gameport subsystem and is taken
49  * every time gameport port or driver registrered or unregistered.
50  */
51 static DEFINE_MUTEX(gameport_mutex);
52
53 static LIST_HEAD(gameport_list);
54
55 static struct bus_type gameport_bus;
56
57 static void gameport_add_driver(struct gameport_driver *drv);
58 static void gameport_add_port(struct gameport *gameport);
59 static void gameport_destroy_port(struct gameport *gameport);
60 static void gameport_reconnect_port(struct gameport *gameport);
61 static void gameport_disconnect_port(struct gameport *gameport);
62
63 #if defined(__i386__)
64
65 #include <asm/i8253.h>
66
67 #define DELTA(x,y)      ((y)-(x)+((y)<(x)?1193182/HZ:0))
68 #define GET_TIME(x)     do { x = get_time_pit(); } while (0)
69
70 static unsigned int get_time_pit(void)
71 {
72         unsigned long flags;
73         unsigned int count;
74
75         spin_lock_irqsave(&i8253_lock, flags);
76         outb_p(0x00, 0x43);
77         count = inb_p(0x40);
78         count |= inb_p(0x40) << 8;
79         spin_unlock_irqrestore(&i8253_lock, flags);
80
81         return count;
82 }
83
84 #endif
85
86
87
88 /*
89  * gameport_measure_speed() measures the gameport i/o speed.
90  */
91
92 static int gameport_measure_speed(struct gameport *gameport)
93 {
94 #if defined(__i386__)
95
96         unsigned int i, t, t1, t2, t3, tx;
97         unsigned long flags;
98
99         if (gameport_open(gameport, NULL, GAMEPORT_MODE_RAW))
100                 return 0;
101
102         tx = 1 << 30;
103
104         for(i = 0; i < 50; i++) {
105                 local_irq_save(flags);
106                 GET_TIME(t1);
107                 for (t = 0; t < 50; t++) gameport_read(gameport);
108                 GET_TIME(t2);
109                 GET_TIME(t3);
110                 local_irq_restore(flags);
111                 udelay(i * 10);
112                 if ((t = DELTA(t2,t1) - DELTA(t3,t2)) < tx) tx = t;
113         }
114
115         gameport_close(gameport);
116         return 59659 / (tx < 1 ? 1 : tx);
117
118 #elif defined (__x86_64__)
119
120         unsigned int i, t;
121         unsigned long tx, t1, t2, flags;
122
123         if (gameport_open(gameport, NULL, GAMEPORT_MODE_RAW))
124                 return 0;
125
126         tx = 1 << 30;
127
128         for(i = 0; i < 50; i++) {
129                 local_irq_save(flags);
130                 rdtscl(t1);
131                 for (t = 0; t < 50; t++) gameport_read(gameport);
132                 rdtscl(t2);
133                 local_irq_restore(flags);
134                 udelay(i * 10);
135                 if (t2 - t1 < tx) tx = t2 - t1;
136         }
137
138         gameport_close(gameport);
139         return (cpu_data[raw_smp_processor_id()].loops_per_jiffy * (unsigned long)HZ / (1000 / 50)) / (tx < 1 ? 1 : tx);
140
141 #else
142
143         unsigned int j, t = 0;
144
145         if (gameport_open(gameport, NULL, GAMEPORT_MODE_RAW))
146                 return 0;
147
148         j = jiffies; while (j == jiffies);
149         j = jiffies; while (j == jiffies) { t++; gameport_read(gameport); }
150
151         gameport_close(gameport);
152         return t * HZ / 1000;
153
154 #endif
155 }
156
157 void gameport_start_polling(struct gameport *gameport)
158 {
159         spin_lock(&gameport->timer_lock);
160
161         if (!gameport->poll_cnt++) {
162                 BUG_ON(!gameport->poll_handler);
163                 BUG_ON(!gameport->poll_interval);
164                 mod_timer(&gameport->poll_timer, jiffies + msecs_to_jiffies(gameport->poll_interval));
165         }
166
167         spin_unlock(&gameport->timer_lock);
168 }
169
170 void gameport_stop_polling(struct gameport *gameport)
171 {
172         spin_lock(&gameport->timer_lock);
173
174         if (!--gameport->poll_cnt)
175                 del_timer(&gameport->poll_timer);
176
177         spin_unlock(&gameport->timer_lock);
178 }
179
180 static void gameport_run_poll_handler(unsigned long d)
181 {
182         struct gameport *gameport = (struct gameport *)d;
183
184         gameport->poll_handler(gameport);
185         if (gameport->poll_cnt)
186                 mod_timer(&gameport->poll_timer, jiffies + msecs_to_jiffies(gameport->poll_interval));
187 }
188
189 /*
190  * Basic gameport -> driver core mappings
191  */
192
193 static void gameport_bind_driver(struct gameport *gameport, struct gameport_driver *drv)
194 {
195         int error;
196
197         down_write(&gameport_bus.subsys.rwsem);
198
199         gameport->dev.driver = &drv->driver;
200         if (drv->connect(gameport, drv)) {
201                 gameport->dev.driver = NULL;
202                 goto out;
203         }
204
205         error = device_bind_driver(&gameport->dev);
206         if (error) {
207                 printk(KERN_WARNING
208                         "gameport: device_bind_driver() failed "
209                         "for %s (%s) and %s, error: %d\n",
210                         gameport->phys, gameport->name,
211                         drv->description, error);
212                 drv->disconnect(gameport);
213                 gameport->dev.driver = NULL;
214                 goto out;
215         }
216
217  out:
218         up_write(&gameport_bus.subsys.rwsem);
219 }
220
221 static void gameport_release_driver(struct gameport *gameport)
222 {
223         down_write(&gameport_bus.subsys.rwsem);
224         device_release_driver(&gameport->dev);
225         up_write(&gameport_bus.subsys.rwsem);
226 }
227
228 static void gameport_find_driver(struct gameport *gameport)
229 {
230         int error;
231
232         down_write(&gameport_bus.subsys.rwsem);
233         error = device_attach(&gameport->dev);
234         if (error < 0)
235                 printk(KERN_WARNING
236                         "gameport: device_attach() failed for %s (%s), error: %d\n",
237                         gameport->phys, gameport->name, error);
238         up_write(&gameport_bus.subsys.rwsem);
239 }
240
241
242 /*
243  * Gameport event processing.
244  */
245
246 enum gameport_event_type {
247         GAMEPORT_RESCAN,
248         GAMEPORT_RECONNECT,
249         GAMEPORT_REGISTER_PORT,
250         GAMEPORT_REGISTER_DRIVER,
251 };
252
253 struct gameport_event {
254         enum gameport_event_type type;
255         void *object;
256         struct module *owner;
257         struct list_head node;
258 };
259
260 static DEFINE_SPINLOCK(gameport_event_lock);    /* protects gameport_event_list */
261 static LIST_HEAD(gameport_event_list);
262 static DECLARE_WAIT_QUEUE_HEAD(gameport_wait);
263 static struct task_struct *gameport_task;
264
265 static void gameport_queue_event(void *object, struct module *owner,
266                               enum gameport_event_type event_type)
267 {
268         unsigned long flags;
269         struct gameport_event *event;
270
271         spin_lock_irqsave(&gameport_event_lock, flags);
272
273         /*
274          * Scan event list for the other events for the same gameport port,
275          * starting with the most recent one. If event is the same we
276          * do not need add new one. If event is of different type we
277          * need to add this event and should not look further because
278          * we need to preseve sequence of distinct events.
279          */
280         list_for_each_entry_reverse(event, &gameport_event_list, node) {
281                 if (event->object == object) {
282                         if (event->type == event_type)
283                                 goto out;
284                         break;
285                 }
286         }
287
288         if ((event = kmalloc(sizeof(struct gameport_event), GFP_ATOMIC))) {
289                 if (!try_module_get(owner)) {
290                         printk(KERN_WARNING "gameport: Can't get module reference, dropping event %d\n", event_type);
291                         kfree(event);
292                         goto out;
293                 }
294
295                 event->type = event_type;
296                 event->object = object;
297                 event->owner = owner;
298
299                 list_add_tail(&event->node, &gameport_event_list);
300                 wake_up(&gameport_wait);
301         } else {
302                 printk(KERN_ERR "gameport: Not enough memory to queue event %d\n", event_type);
303         }
304 out:
305         spin_unlock_irqrestore(&gameport_event_lock, flags);
306 }
307
308 static void gameport_free_event(struct gameport_event *event)
309 {
310         module_put(event->owner);
311         kfree(event);
312 }
313
314 static void gameport_remove_duplicate_events(struct gameport_event *event)
315 {
316         struct list_head *node, *next;
317         struct gameport_event *e;
318         unsigned long flags;
319
320         spin_lock_irqsave(&gameport_event_lock, flags);
321
322         list_for_each_safe(node, next, &gameport_event_list) {
323                 e = list_entry(node, struct gameport_event, node);
324                 if (event->object == e->object) {
325                         /*
326                          * If this event is of different type we should not
327                          * look further - we only suppress duplicate events
328                          * that were sent back-to-back.
329                          */
330                         if (event->type != e->type)
331                                 break;
332
333                         list_del_init(node);
334                         gameport_free_event(e);
335                 }
336         }
337
338         spin_unlock_irqrestore(&gameport_event_lock, flags);
339 }
340
341 static struct gameport_event *gameport_get_event(void)
342 {
343         struct gameport_event *event;
344         struct list_head *node;
345         unsigned long flags;
346
347         spin_lock_irqsave(&gameport_event_lock, flags);
348
349         if (list_empty(&gameport_event_list)) {
350                 spin_unlock_irqrestore(&gameport_event_lock, flags);
351                 return NULL;
352         }
353
354         node = gameport_event_list.next;
355         event = list_entry(node, struct gameport_event, node);
356         list_del_init(node);
357
358         spin_unlock_irqrestore(&gameport_event_lock, flags);
359
360         return event;
361 }
362
363 static void gameport_handle_event(void)
364 {
365         struct gameport_event *event;
366
367         mutex_lock(&gameport_mutex);
368
369         /*
370          * Note that we handle only one event here to give swsusp
371          * a chance to freeze kgameportd thread. Gameport events
372          * should be pretty rare so we are not concerned about
373          * taking performance hit.
374          */
375         if ((event = gameport_get_event())) {
376
377                 switch (event->type) {
378                         case GAMEPORT_REGISTER_PORT:
379                                 gameport_add_port(event->object);
380                                 break;
381
382                         case GAMEPORT_RECONNECT:
383                                 gameport_reconnect_port(event->object);
384                                 break;
385
386                         case GAMEPORT_RESCAN:
387                                 gameport_disconnect_port(event->object);
388                                 gameport_find_driver(event->object);
389                                 break;
390
391                         case GAMEPORT_REGISTER_DRIVER:
392                                 gameport_add_driver(event->object);
393                                 break;
394
395                         default:
396                                 break;
397                 }
398
399                 gameport_remove_duplicate_events(event);
400                 gameport_free_event(event);
401         }
402
403         mutex_unlock(&gameport_mutex);
404 }
405
406 /*
407  * Remove all events that have been submitted for a given gameport port.
408  */
409 static void gameport_remove_pending_events(struct gameport *gameport)
410 {
411         struct list_head *node, *next;
412         struct gameport_event *event;
413         unsigned long flags;
414
415         spin_lock_irqsave(&gameport_event_lock, flags);
416
417         list_for_each_safe(node, next, &gameport_event_list) {
418                 event = list_entry(node, struct gameport_event, node);
419                 if (event->object == gameport) {
420                         list_del_init(node);
421                         gameport_free_event(event);
422                 }
423         }
424
425         spin_unlock_irqrestore(&gameport_event_lock, flags);
426 }
427
428 /*
429  * Destroy child gameport port (if any) that has not been fully registered yet.
430  *
431  * Note that we rely on the fact that port can have only one child and therefore
432  * only one child registration request can be pending. Additionally, children
433  * are registered by driver's connect() handler so there can't be a grandchild
434  * pending registration together with a child.
435  */
436 static struct gameport *gameport_get_pending_child(struct gameport *parent)
437 {
438         struct gameport_event *event;
439         struct gameport *gameport, *child = NULL;
440         unsigned long flags;
441
442         spin_lock_irqsave(&gameport_event_lock, flags);
443
444         list_for_each_entry(event, &gameport_event_list, node) {
445                 if (event->type == GAMEPORT_REGISTER_PORT) {
446                         gameport = event->object;
447                         if (gameport->parent == parent) {
448                                 child = gameport;
449                                 break;
450                         }
451                 }
452         }
453
454         spin_unlock_irqrestore(&gameport_event_lock, flags);
455         return child;
456 }
457
458 static int gameport_thread(void *nothing)
459 {
460         do {
461                 gameport_handle_event();
462                 wait_event_interruptible(gameport_wait,
463                         kthread_should_stop() || !list_empty(&gameport_event_list));
464                 try_to_freeze();
465         } while (!kthread_should_stop());
466
467         printk(KERN_DEBUG "gameport: kgameportd exiting\n");
468         return 0;
469 }
470
471
472 /*
473  * Gameport port operations
474  */
475
476 static ssize_t gameport_show_description(struct device *dev, struct device_attribute *attr, char *buf)
477 {
478         struct gameport *gameport = to_gameport_port(dev);
479         return sprintf(buf, "%s\n", gameport->name);
480 }
481
482 static ssize_t gameport_rebind_driver(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
483 {
484         struct gameport *gameport = to_gameport_port(dev);
485         struct device_driver *drv;
486         int retval;
487
488         retval = mutex_lock_interruptible(&gameport_mutex);
489         if (retval)
490                 return retval;
491
492         retval = count;
493         if (!strncmp(buf, "none", count)) {
494                 gameport_disconnect_port(gameport);
495         } else if (!strncmp(buf, "reconnect", count)) {
496                 gameport_reconnect_port(gameport);
497         } else if (!strncmp(buf, "rescan", count)) {
498                 gameport_disconnect_port(gameport);
499                 gameport_find_driver(gameport);
500         } else if ((drv = driver_find(buf, &gameport_bus)) != NULL) {
501                 gameport_disconnect_port(gameport);
502                 gameport_bind_driver(gameport, to_gameport_driver(drv));
503                 put_driver(drv);
504         } else {
505                 retval = -EINVAL;
506         }
507
508         mutex_unlock(&gameport_mutex);
509
510         return retval;
511 }
512
513 static struct device_attribute gameport_device_attrs[] = {
514         __ATTR(description, S_IRUGO, gameport_show_description, NULL),
515         __ATTR(drvctl, S_IWUSR, NULL, gameport_rebind_driver),
516         __ATTR_NULL
517 };
518
519 static void gameport_release_port(struct device *dev)
520 {
521         struct gameport *gameport = to_gameport_port(dev);
522
523         kfree(gameport);
524         module_put(THIS_MODULE);
525 }
526
527 void gameport_set_phys(struct gameport *gameport, const char *fmt, ...)
528 {
529         va_list args;
530
531         va_start(args, fmt);
532         vsnprintf(gameport->phys, sizeof(gameport->phys), fmt, args);
533         va_end(args);
534 }
535
536 /*
537  * Prepare gameport port for registration.
538  */
539 static void gameport_init_port(struct gameport *gameport)
540 {
541         static atomic_t gameport_no = ATOMIC_INIT(0);
542
543         __module_get(THIS_MODULE);
544
545         mutex_init(&gameport->drv_mutex);
546         device_initialize(&gameport->dev);
547         snprintf(gameport->dev.bus_id, sizeof(gameport->dev.bus_id),
548                  "gameport%lu", (unsigned long)atomic_inc_return(&gameport_no) - 1);
549         gameport->dev.bus = &gameport_bus;
550         gameport->dev.release = gameport_release_port;
551         if (gameport->parent)
552                 gameport->dev.parent = &gameport->parent->dev;
553
554         INIT_LIST_HEAD(&gameport->node);
555         spin_lock_init(&gameport->timer_lock);
556         init_timer(&gameport->poll_timer);
557         gameport->poll_timer.function = gameport_run_poll_handler;
558         gameport->poll_timer.data = (unsigned long)gameport;
559 }
560
561 /*
562  * Complete gameport port registration.
563  * Driver core will attempt to find appropriate driver for the port.
564  */
565 static void gameport_add_port(struct gameport *gameport)
566 {
567         int error;
568
569         if (gameport->parent)
570                 gameport->parent->child = gameport;
571
572         gameport->speed = gameport_measure_speed(gameport);
573
574         list_add_tail(&gameport->node, &gameport_list);
575
576         if (gameport->io)
577                 printk(KERN_INFO "gameport: %s is %s, io %#x, speed %dkHz\n",
578                         gameport->name, gameport->phys, gameport->io, gameport->speed);
579         else
580                 printk(KERN_INFO "gameport: %s is %s, speed %dkHz\n",
581                         gameport->name, gameport->phys, gameport->speed);
582
583         error = device_add(&gameport->dev);
584         if (error)
585                 printk(KERN_ERR
586                         "gameport: device_add() failed for %s (%s), error: %d\n",
587                         gameport->phys, gameport->name, error);
588         else
589                 gameport->registered = 1;
590 }
591
592 /*
593  * gameport_destroy_port() completes deregistration process and removes
594  * port from the system
595  */
596 static void gameport_destroy_port(struct gameport *gameport)
597 {
598         struct gameport *child;
599
600         child = gameport_get_pending_child(gameport);
601         if (child) {
602                 gameport_remove_pending_events(child);
603                 put_device(&child->dev);
604         }
605
606         if (gameport->parent) {
607                 gameport->parent->child = NULL;
608                 gameport->parent = NULL;
609         }
610
611         if (gameport->registered) {
612                 device_del(&gameport->dev);
613                 gameport->registered = 0;
614         }
615
616         list_del_init(&gameport->node);
617
618         gameport_remove_pending_events(gameport);
619         put_device(&gameport->dev);
620 }
621
622 /*
623  * Reconnect gameport port and all its children (re-initialize attached devices)
624  */
625 static void gameport_reconnect_port(struct gameport *gameport)
626 {
627         do {
628                 if (!gameport->drv || !gameport->drv->reconnect || gameport->drv->reconnect(gameport)) {
629                         gameport_disconnect_port(gameport);
630                         gameport_find_driver(gameport);
631                         /* Ok, old children are now gone, we are done */
632                         break;
633                 }
634                 gameport = gameport->child;
635         } while (gameport);
636 }
637
638 /*
639  * gameport_disconnect_port() unbinds a port from its driver. As a side effect
640  * all child ports are unbound and destroyed.
641  */
642 static void gameport_disconnect_port(struct gameport *gameport)
643 {
644         struct gameport *s, *parent;
645
646         if (gameport->child) {
647                 /*
648                  * Children ports should be disconnected and destroyed
649                  * first, staring with the leaf one, since we don't want
650                  * to do recursion
651                  */
652                 for (s = gameport; s->child; s = s->child)
653                         /* empty */;
654
655                 do {
656                         parent = s->parent;
657
658                         gameport_release_driver(s);
659                         gameport_destroy_port(s);
660                 } while ((s = parent) != gameport);
661         }
662
663         /*
664          * Ok, no children left, now disconnect this port
665          */
666         gameport_release_driver(gameport);
667 }
668
669 void gameport_rescan(struct gameport *gameport)
670 {
671         gameport_queue_event(gameport, NULL, GAMEPORT_RESCAN);
672 }
673
674 void gameport_reconnect(struct gameport *gameport)
675 {
676         gameport_queue_event(gameport, NULL, GAMEPORT_RECONNECT);
677 }
678
679 /*
680  * Submits register request to kgameportd for subsequent execution.
681  * Note that port registration is always asynchronous.
682  */
683 void __gameport_register_port(struct gameport *gameport, struct module *owner)
684 {
685         gameport_init_port(gameport);
686         gameport_queue_event(gameport, owner, GAMEPORT_REGISTER_PORT);
687 }
688
689 /*
690  * Synchronously unregisters gameport port.
691  */
692 void gameport_unregister_port(struct gameport *gameport)
693 {
694         mutex_lock(&gameport_mutex);
695         gameport_disconnect_port(gameport);
696         gameport_destroy_port(gameport);
697         mutex_unlock(&gameport_mutex);
698 }
699
700
701 /*
702  * Gameport driver operations
703  */
704
705 static ssize_t gameport_driver_show_description(struct device_driver *drv, char *buf)
706 {
707         struct gameport_driver *driver = to_gameport_driver(drv);
708         return sprintf(buf, "%s\n", driver->description ? driver->description : "(none)");
709 }
710
711 static struct driver_attribute gameport_driver_attrs[] = {
712         __ATTR(description, S_IRUGO, gameport_driver_show_description, NULL),
713         __ATTR_NULL
714 };
715
716 static int gameport_driver_probe(struct device *dev)
717 {
718         struct gameport *gameport = to_gameport_port(dev);
719         struct gameport_driver *drv = to_gameport_driver(dev->driver);
720
721         drv->connect(gameport, drv);
722         return gameport->drv ? 0 : -ENODEV;
723 }
724
725 static int gameport_driver_remove(struct device *dev)
726 {
727         struct gameport *gameport = to_gameport_port(dev);
728         struct gameport_driver *drv = to_gameport_driver(dev->driver);
729
730         drv->disconnect(gameport);
731         return 0;
732 }
733
734 static struct bus_type gameport_bus = {
735         .name   = "gameport",
736         .probe  = gameport_driver_probe,
737         .remove = gameport_driver_remove,
738 };
739
740 static void gameport_add_driver(struct gameport_driver *drv)
741 {
742         int error;
743
744         error = driver_register(&drv->driver);
745         if (error)
746                 printk(KERN_ERR
747                         "gameport: driver_register() failed for %s, error: %d\n",
748                         drv->driver.name, error);
749 }
750
751 void __gameport_register_driver(struct gameport_driver *drv, struct module *owner)
752 {
753         drv->driver.bus = &gameport_bus;
754         gameport_queue_event(drv, owner, GAMEPORT_REGISTER_DRIVER);
755 }
756
757 void gameport_unregister_driver(struct gameport_driver *drv)
758 {
759         struct gameport *gameport;
760
761         mutex_lock(&gameport_mutex);
762         drv->ignore = 1;        /* so gameport_find_driver ignores it */
763
764 start_over:
765         list_for_each_entry(gameport, &gameport_list, node) {
766                 if (gameport->drv == drv) {
767                         gameport_disconnect_port(gameport);
768                         gameport_find_driver(gameport);
769                         /* we could've deleted some ports, restart */
770                         goto start_over;
771                 }
772         }
773
774         driver_unregister(&drv->driver);
775         mutex_unlock(&gameport_mutex);
776 }
777
778 static int gameport_bus_match(struct device *dev, struct device_driver *drv)
779 {
780         struct gameport_driver *gameport_drv = to_gameport_driver(drv);
781
782         return !gameport_drv->ignore;
783 }
784
785 static void gameport_set_drv(struct gameport *gameport, struct gameport_driver *drv)
786 {
787         mutex_lock(&gameport->drv_mutex);
788         gameport->drv = drv;
789         mutex_unlock(&gameport->drv_mutex);
790 }
791
792 int gameport_open(struct gameport *gameport, struct gameport_driver *drv, int mode)
793 {
794
795         if (gameport->open) {
796                 if (gameport->open(gameport, mode)) {
797                         return -1;
798                 }
799         } else {
800                 if (mode != GAMEPORT_MODE_RAW)
801                         return -1;
802         }
803
804         gameport_set_drv(gameport, drv);
805         return 0;
806 }
807
808 void gameport_close(struct gameport *gameport)
809 {
810         del_timer_sync(&gameport->poll_timer);
811         gameport->poll_handler = NULL;
812         gameport->poll_interval = 0;
813         gameport_set_drv(gameport, NULL);
814         if (gameport->close)
815                 gameport->close(gameport);
816 }
817
818 static int __init gameport_init(void)
819 {
820         int error;
821
822         gameport_bus.dev_attrs = gameport_device_attrs;
823         gameport_bus.drv_attrs = gameport_driver_attrs;
824         gameport_bus.match = gameport_bus_match;
825         error = bus_register(&gameport_bus);
826         if (error) {
827                 printk(KERN_ERR "gameport: failed to register gameport bus, error: %d\n", error);
828                 return error;
829         }
830
831         gameport_task = kthread_run(gameport_thread, NULL, "kgameportd");
832         if (IS_ERR(gameport_task)) {
833                 bus_unregister(&gameport_bus);
834                 error = PTR_ERR(gameport_task);
835                 printk(KERN_ERR "gameport: Failed to start kgameportd, error: %d\n", error);
836                 return error;
837         }
838
839         return 0;
840 }
841
842 static void __exit gameport_exit(void)
843 {
844         bus_unregister(&gameport_bus);
845         kthread_stop(gameport_task);
846 }
847
848 subsys_initcall(gameport_init);
849 module_exit(gameport_exit);