2 * Generic gameport layer
4 * Copyright (c) 1999-2002 Vojtech Pavlik
5 * Copyright (c) 2005 Dmitry Torokhov
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.
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>
27 /*#include <asm/io.h>*/
29 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
30 MODULE_DESCRIPTION("Generic gameport layer");
31 MODULE_LICENSE("GPL");
33 EXPORT_SYMBOL(__gameport_register_port
);
34 EXPORT_SYMBOL(gameport_unregister_port
);
35 EXPORT_SYMBOL(__gameport_register_driver
);
36 EXPORT_SYMBOL(gameport_unregister_driver
);
37 EXPORT_SYMBOL(gameport_open
);
38 EXPORT_SYMBOL(gameport_close
);
39 EXPORT_SYMBOL(gameport_rescan
);
40 EXPORT_SYMBOL(gameport_cooked_read
);
41 EXPORT_SYMBOL(gameport_set_name
);
42 EXPORT_SYMBOL(gameport_set_phys
);
43 EXPORT_SYMBOL(gameport_start_polling
);
44 EXPORT_SYMBOL(gameport_stop_polling
);
47 * gameport_mutex protects entire gameport subsystem and is taken
48 * every time gameport port or driver registrered or unregistered.
50 static DEFINE_MUTEX(gameport_mutex
);
52 static LIST_HEAD(gameport_list
);
54 static struct bus_type gameport_bus
;
56 static void gameport_add_driver(struct gameport_driver
*drv
);
57 static void gameport_add_port(struct gameport
*gameport
);
58 static void gameport_destroy_port(struct gameport
*gameport
);
59 static void gameport_reconnect_port(struct gameport
*gameport
);
60 static void gameport_disconnect_port(struct gameport
*gameport
);
64 #include <asm/i8253.h>
66 #define DELTA(x,y) ((y)-(x)+((y)<(x)?1193182/HZ:0))
67 #define GET_TIME(x) do { x = get_time_pit(); } while (0)
69 static unsigned int get_time_pit(void)
74 spin_lock_irqsave(&i8253_lock
, flags
);
77 count
|= inb_p(0x40) << 8;
78 spin_unlock_irqrestore(&i8253_lock
, flags
);
88 * gameport_measure_speed() measures the gameport i/o speed.
91 static int gameport_measure_speed(struct gameport
*gameport
)
95 unsigned int i
, t
, t1
, t2
, t3
, tx
;
98 if (gameport_open(gameport
, NULL
, GAMEPORT_MODE_RAW
))
103 for(i
= 0; i
< 50; i
++) {
104 local_irq_save(flags
);
106 for (t
= 0; t
< 50; t
++) gameport_read(gameport
);
109 local_irq_restore(flags
);
111 if ((t
= DELTA(t2
,t1
) - DELTA(t3
,t2
)) < tx
) tx
= t
;
114 gameport_close(gameport
);
115 return 59659 / (tx
< 1 ? 1 : tx
);
117 #elif defined (__x86_64__)
120 unsigned long tx
, t1
, t2
, flags
;
122 if (gameport_open(gameport
, NULL
, GAMEPORT_MODE_RAW
))
127 for(i
= 0; i
< 50; i
++) {
128 local_irq_save(flags
);
130 for (t
= 0; t
< 50; t
++) gameport_read(gameport
);
132 local_irq_restore(flags
);
134 if (t2
- t1
< tx
) tx
= t2
- t1
;
137 gameport_close(gameport
);
138 return (cpu_data
[raw_smp_processor_id()].loops_per_jiffy
* (unsigned long)HZ
/ (1000 / 50)) / (tx
< 1 ? 1 : tx
);
142 unsigned int j
, t
= 0;
144 if (gameport_open(gameport
, NULL
, GAMEPORT_MODE_RAW
))
147 j
= jiffies
; while (j
== jiffies
);
148 j
= jiffies
; while (j
== jiffies
) { t
++; gameport_read(gameport
); }
150 gameport_close(gameport
);
151 return t
* HZ
/ 1000;
156 void gameport_start_polling(struct gameport
*gameport
)
158 spin_lock(&gameport
->timer_lock
);
160 if (!gameport
->poll_cnt
++) {
161 BUG_ON(!gameport
->poll_handler
);
162 BUG_ON(!gameport
->poll_interval
);
163 mod_timer(&gameport
->poll_timer
, jiffies
+ msecs_to_jiffies(gameport
->poll_interval
));
166 spin_unlock(&gameport
->timer_lock
);
169 void gameport_stop_polling(struct gameport
*gameport
)
171 spin_lock(&gameport
->timer_lock
);
173 if (!--gameport
->poll_cnt
)
174 del_timer(&gameport
->poll_timer
);
176 spin_unlock(&gameport
->timer_lock
);
179 static void gameport_run_poll_handler(unsigned long d
)
181 struct gameport
*gameport
= (struct gameport
*)d
;
183 gameport
->poll_handler(gameport
);
184 if (gameport
->poll_cnt
)
185 mod_timer(&gameport
->poll_timer
, jiffies
+ msecs_to_jiffies(gameport
->poll_interval
));
189 * Basic gameport -> driver core mappings
192 static void gameport_bind_driver(struct gameport
*gameport
, struct gameport_driver
*drv
)
196 down_write(&gameport_bus
.subsys
.rwsem
);
198 gameport
->dev
.driver
= &drv
->driver
;
199 if (drv
->connect(gameport
, drv
)) {
200 gameport
->dev
.driver
= NULL
;
204 error
= device_bind_driver(&gameport
->dev
);
207 "gameport: device_bind_driver() failed "
208 "for %s (%s) and %s, error: %d\n",
209 gameport
->phys
, gameport
->name
,
210 drv
->description
, error
);
211 drv
->disconnect(gameport
);
212 gameport
->dev
.driver
= NULL
;
217 up_write(&gameport_bus
.subsys
.rwsem
);
220 static void gameport_release_driver(struct gameport
*gameport
)
222 down_write(&gameport_bus
.subsys
.rwsem
);
223 device_release_driver(&gameport
->dev
);
224 up_write(&gameport_bus
.subsys
.rwsem
);
227 static void gameport_find_driver(struct gameport
*gameport
)
231 down_write(&gameport_bus
.subsys
.rwsem
);
232 error
= device_attach(&gameport
->dev
);
235 "gameport: device_attach() failed for %s (%s), error: %d\n",
236 gameport
->phys
, gameport
->name
, error
);
237 up_write(&gameport_bus
.subsys
.rwsem
);
242 * Gameport event processing.
245 enum gameport_event_type
{
248 GAMEPORT_REGISTER_PORT
,
249 GAMEPORT_REGISTER_DRIVER
,
252 struct gameport_event
{
253 enum gameport_event_type type
;
255 struct module
*owner
;
256 struct list_head node
;
259 static DEFINE_SPINLOCK(gameport_event_lock
); /* protects gameport_event_list */
260 static LIST_HEAD(gameport_event_list
);
261 static DECLARE_WAIT_QUEUE_HEAD(gameport_wait
);
262 static struct task_struct
*gameport_task
;
264 static void gameport_queue_event(void *object
, struct module
*owner
,
265 enum gameport_event_type event_type
)
268 struct gameport_event
*event
;
270 spin_lock_irqsave(&gameport_event_lock
, flags
);
273 * Scan event list for the other events for the same gameport port,
274 * starting with the most recent one. If event is the same we
275 * do not need add new one. If event is of different type we
276 * need to add this event and should not look further because
277 * we need to preseve sequence of distinct events.
279 list_for_each_entry_reverse(event
, &gameport_event_list
, node
) {
280 if (event
->object
== object
) {
281 if (event
->type
== event_type
)
287 if ((event
= kmalloc(sizeof(struct gameport_event
), GFP_ATOMIC
))) {
288 if (!try_module_get(owner
)) {
289 printk(KERN_WARNING
"gameport: Can't get module reference, dropping event %d\n", event_type
);
294 event
->type
= event_type
;
295 event
->object
= object
;
296 event
->owner
= owner
;
298 list_add_tail(&event
->node
, &gameport_event_list
);
299 wake_up(&gameport_wait
);
301 printk(KERN_ERR
"gameport: Not enough memory to queue event %d\n", event_type
);
304 spin_unlock_irqrestore(&gameport_event_lock
, flags
);
307 static void gameport_free_event(struct gameport_event
*event
)
309 module_put(event
->owner
);
313 static void gameport_remove_duplicate_events(struct gameport_event
*event
)
315 struct list_head
*node
, *next
;
316 struct gameport_event
*e
;
319 spin_lock_irqsave(&gameport_event_lock
, flags
);
321 list_for_each_safe(node
, next
, &gameport_event_list
) {
322 e
= list_entry(node
, struct gameport_event
, node
);
323 if (event
->object
== e
->object
) {
325 * If this event is of different type we should not
326 * look further - we only suppress duplicate events
327 * that were sent back-to-back.
329 if (event
->type
!= e
->type
)
333 gameport_free_event(e
);
337 spin_unlock_irqrestore(&gameport_event_lock
, flags
);
340 static struct gameport_event
*gameport_get_event(void)
342 struct gameport_event
*event
;
343 struct list_head
*node
;
346 spin_lock_irqsave(&gameport_event_lock
, flags
);
348 if (list_empty(&gameport_event_list
)) {
349 spin_unlock_irqrestore(&gameport_event_lock
, flags
);
353 node
= gameport_event_list
.next
;
354 event
= list_entry(node
, struct gameport_event
, node
);
357 spin_unlock_irqrestore(&gameport_event_lock
, flags
);
362 static void gameport_handle_event(void)
364 struct gameport_event
*event
;
366 mutex_lock(&gameport_mutex
);
369 * Note that we handle only one event here to give swsusp
370 * a chance to freeze kgameportd thread. Gameport events
371 * should be pretty rare so we are not concerned about
372 * taking performance hit.
374 if ((event
= gameport_get_event())) {
376 switch (event
->type
) {
377 case GAMEPORT_REGISTER_PORT
:
378 gameport_add_port(event
->object
);
381 case GAMEPORT_RECONNECT
:
382 gameport_reconnect_port(event
->object
);
385 case GAMEPORT_RESCAN
:
386 gameport_disconnect_port(event
->object
);
387 gameport_find_driver(event
->object
);
390 case GAMEPORT_REGISTER_DRIVER
:
391 gameport_add_driver(event
->object
);
398 gameport_remove_duplicate_events(event
);
399 gameport_free_event(event
);
402 mutex_unlock(&gameport_mutex
);
406 * Remove all events that have been submitted for a given gameport port.
408 static void gameport_remove_pending_events(struct gameport
*gameport
)
410 struct list_head
*node
, *next
;
411 struct gameport_event
*event
;
414 spin_lock_irqsave(&gameport_event_lock
, flags
);
416 list_for_each_safe(node
, next
, &gameport_event_list
) {
417 event
= list_entry(node
, struct gameport_event
, node
);
418 if (event
->object
== gameport
) {
420 gameport_free_event(event
);
424 spin_unlock_irqrestore(&gameport_event_lock
, flags
);
428 * Destroy child gameport port (if any) that has not been fully registered yet.
430 * Note that we rely on the fact that port can have only one child and therefore
431 * only one child registration request can be pending. Additionally, children
432 * are registered by driver's connect() handler so there can't be a grandchild
433 * pending registration together with a child.
435 static struct gameport
*gameport_get_pending_child(struct gameport
*parent
)
437 struct gameport_event
*event
;
438 struct gameport
*gameport
, *child
= NULL
;
441 spin_lock_irqsave(&gameport_event_lock
, flags
);
443 list_for_each_entry(event
, &gameport_event_list
, node
) {
444 if (event
->type
== GAMEPORT_REGISTER_PORT
) {
445 gameport
= event
->object
;
446 if (gameport
->parent
== parent
) {
453 spin_unlock_irqrestore(&gameport_event_lock
, flags
);
457 static int gameport_thread(void *nothing
)
460 gameport_handle_event();
461 wait_event_interruptible(gameport_wait
,
462 kthread_should_stop() || !list_empty(&gameport_event_list
));
464 } while (!kthread_should_stop());
466 printk(KERN_DEBUG
"gameport: kgameportd exiting\n");
472 * Gameport port operations
475 static ssize_t
gameport_show_description(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
477 struct gameport
*gameport
= to_gameport_port(dev
);
478 return sprintf(buf
, "%s\n", gameport
->name
);
481 static ssize_t
gameport_rebind_driver(struct device
*dev
, struct device_attribute
*attr
, const char *buf
, size_t count
)
483 struct gameport
*gameport
= to_gameport_port(dev
);
484 struct device_driver
*drv
;
487 retval
= mutex_lock_interruptible(&gameport_mutex
);
492 if (!strncmp(buf
, "none", count
)) {
493 gameport_disconnect_port(gameport
);
494 } else if (!strncmp(buf
, "reconnect", count
)) {
495 gameport_reconnect_port(gameport
);
496 } else if (!strncmp(buf
, "rescan", count
)) {
497 gameport_disconnect_port(gameport
);
498 gameport_find_driver(gameport
);
499 } else if ((drv
= driver_find(buf
, &gameport_bus
)) != NULL
) {
500 gameport_disconnect_port(gameport
);
501 gameport_bind_driver(gameport
, to_gameport_driver(drv
));
507 mutex_unlock(&gameport_mutex
);
512 static struct device_attribute gameport_device_attrs
[] = {
513 __ATTR(description
, S_IRUGO
, gameport_show_description
, NULL
),
514 __ATTR(drvctl
, S_IWUSR
, NULL
, gameport_rebind_driver
),
518 static void gameport_release_port(struct device
*dev
)
520 struct gameport
*gameport
= to_gameport_port(dev
);
523 module_put(THIS_MODULE
);
526 void gameport_set_phys(struct gameport
*gameport
, const char *fmt
, ...)
531 vsnprintf(gameport
->phys
, sizeof(gameport
->phys
), fmt
, args
);
536 * Prepare gameport port for registration.
538 static void gameport_init_port(struct gameport
*gameport
)
540 static atomic_t gameport_no
= ATOMIC_INIT(0);
542 __module_get(THIS_MODULE
);
544 mutex_init(&gameport
->drv_mutex
);
545 device_initialize(&gameport
->dev
);
546 snprintf(gameport
->dev
.bus_id
, sizeof(gameport
->dev
.bus_id
),
547 "gameport%lu", (unsigned long)atomic_inc_return(&gameport_no
) - 1);
548 gameport
->dev
.bus
= &gameport_bus
;
549 gameport
->dev
.release
= gameport_release_port
;
550 if (gameport
->parent
)
551 gameport
->dev
.parent
= &gameport
->parent
->dev
;
553 INIT_LIST_HEAD(&gameport
->node
);
554 spin_lock_init(&gameport
->timer_lock
);
555 init_timer(&gameport
->poll_timer
);
556 gameport
->poll_timer
.function
= gameport_run_poll_handler
;
557 gameport
->poll_timer
.data
= (unsigned long)gameport
;
561 * Complete gameport port registration.
562 * Driver core will attempt to find appropriate driver for the port.
564 static void gameport_add_port(struct gameport
*gameport
)
568 if (gameport
->parent
)
569 gameport
->parent
->child
= gameport
;
571 gameport
->speed
= gameport_measure_speed(gameport
);
573 list_add_tail(&gameport
->node
, &gameport_list
);
576 printk(KERN_INFO
"gameport: %s is %s, io %#x, speed %dkHz\n",
577 gameport
->name
, gameport
->phys
, gameport
->io
, gameport
->speed
);
579 printk(KERN_INFO
"gameport: %s is %s, speed %dkHz\n",
580 gameport
->name
, gameport
->phys
, gameport
->speed
);
582 error
= device_add(&gameport
->dev
);
585 "gameport: device_add() failed for %s (%s), error: %d\n",
586 gameport
->phys
, gameport
->name
, error
);
588 gameport
->registered
= 1;
592 * gameport_destroy_port() completes deregistration process and removes
593 * port from the system
595 static void gameport_destroy_port(struct gameport
*gameport
)
597 struct gameport
*child
;
599 child
= gameport_get_pending_child(gameport
);
601 gameport_remove_pending_events(child
);
602 put_device(&child
->dev
);
605 if (gameport
->parent
) {
606 gameport
->parent
->child
= NULL
;
607 gameport
->parent
= NULL
;
610 if (gameport
->registered
) {
611 device_del(&gameport
->dev
);
612 gameport
->registered
= 0;
615 list_del_init(&gameport
->node
);
617 gameport_remove_pending_events(gameport
);
618 put_device(&gameport
->dev
);
622 * Reconnect gameport port and all its children (re-initialize attached devices)
624 static void gameport_reconnect_port(struct gameport
*gameport
)
627 if (!gameport
->drv
|| !gameport
->drv
->reconnect
|| gameport
->drv
->reconnect(gameport
)) {
628 gameport_disconnect_port(gameport
);
629 gameport_find_driver(gameport
);
630 /* Ok, old children are now gone, we are done */
633 gameport
= gameport
->child
;
638 * gameport_disconnect_port() unbinds a port from its driver. As a side effect
639 * all child ports are unbound and destroyed.
641 static void gameport_disconnect_port(struct gameport
*gameport
)
643 struct gameport
*s
, *parent
;
645 if (gameport
->child
) {
647 * Children ports should be disconnected and destroyed
648 * first, staring with the leaf one, since we don't want
651 for (s
= gameport
; s
->child
; s
= s
->child
)
657 gameport_release_driver(s
);
658 gameport_destroy_port(s
);
659 } while ((s
= parent
) != gameport
);
663 * Ok, no children left, now disconnect this port
665 gameport_release_driver(gameport
);
668 void gameport_rescan(struct gameport
*gameport
)
670 gameport_queue_event(gameport
, NULL
, GAMEPORT_RESCAN
);
673 void gameport_reconnect(struct gameport
*gameport
)
675 gameport_queue_event(gameport
, NULL
, GAMEPORT_RECONNECT
);
679 * Submits register request to kgameportd for subsequent execution.
680 * Note that port registration is always asynchronous.
682 void __gameport_register_port(struct gameport
*gameport
, struct module
*owner
)
684 gameport_init_port(gameport
);
685 gameport_queue_event(gameport
, owner
, GAMEPORT_REGISTER_PORT
);
689 * Synchronously unregisters gameport port.
691 void gameport_unregister_port(struct gameport
*gameport
)
693 mutex_lock(&gameport_mutex
);
694 gameport_disconnect_port(gameport
);
695 gameport_destroy_port(gameport
);
696 mutex_unlock(&gameport_mutex
);
701 * Gameport driver operations
704 static ssize_t
gameport_driver_show_description(struct device_driver
*drv
, char *buf
)
706 struct gameport_driver
*driver
= to_gameport_driver(drv
);
707 return sprintf(buf
, "%s\n", driver
->description
? driver
->description
: "(none)");
710 static struct driver_attribute gameport_driver_attrs
[] = {
711 __ATTR(description
, S_IRUGO
, gameport_driver_show_description
, NULL
),
715 static int gameport_driver_probe(struct device
*dev
)
717 struct gameport
*gameport
= to_gameport_port(dev
);
718 struct gameport_driver
*drv
= to_gameport_driver(dev
->driver
);
720 drv
->connect(gameport
, drv
);
721 return gameport
->drv
? 0 : -ENODEV
;
724 static int gameport_driver_remove(struct device
*dev
)
726 struct gameport
*gameport
= to_gameport_port(dev
);
727 struct gameport_driver
*drv
= to_gameport_driver(dev
->driver
);
729 drv
->disconnect(gameport
);
733 static struct bus_type gameport_bus
= {
735 .probe
= gameport_driver_probe
,
736 .remove
= gameport_driver_remove
,
739 static void gameport_add_driver(struct gameport_driver
*drv
)
743 error
= driver_register(&drv
->driver
);
746 "gameport: driver_register() failed for %s, error: %d\n",
747 drv
->driver
.name
, error
);
750 void __gameport_register_driver(struct gameport_driver
*drv
, struct module
*owner
)
752 drv
->driver
.bus
= &gameport_bus
;
753 gameport_queue_event(drv
, owner
, GAMEPORT_REGISTER_DRIVER
);
756 void gameport_unregister_driver(struct gameport_driver
*drv
)
758 struct gameport
*gameport
;
760 mutex_lock(&gameport_mutex
);
761 drv
->ignore
= 1; /* so gameport_find_driver ignores it */
764 list_for_each_entry(gameport
, &gameport_list
, node
) {
765 if (gameport
->drv
== drv
) {
766 gameport_disconnect_port(gameport
);
767 gameport_find_driver(gameport
);
768 /* we could've deleted some ports, restart */
773 driver_unregister(&drv
->driver
);
774 mutex_unlock(&gameport_mutex
);
777 static int gameport_bus_match(struct device
*dev
, struct device_driver
*drv
)
779 struct gameport_driver
*gameport_drv
= to_gameport_driver(drv
);
781 return !gameport_drv
->ignore
;
784 static void gameport_set_drv(struct gameport
*gameport
, struct gameport_driver
*drv
)
786 mutex_lock(&gameport
->drv_mutex
);
788 mutex_unlock(&gameport
->drv_mutex
);
791 int gameport_open(struct gameport
*gameport
, struct gameport_driver
*drv
, int mode
)
794 if (gameport
->open
) {
795 if (gameport
->open(gameport
, mode
)) {
799 if (mode
!= GAMEPORT_MODE_RAW
)
803 gameport_set_drv(gameport
, drv
);
807 void gameport_close(struct gameport
*gameport
)
809 del_timer_sync(&gameport
->poll_timer
);
810 gameport
->poll_handler
= NULL
;
811 gameport
->poll_interval
= 0;
812 gameport_set_drv(gameport
, NULL
);
814 gameport
->close(gameport
);
817 static int __init
gameport_init(void)
821 gameport_bus
.dev_attrs
= gameport_device_attrs
;
822 gameport_bus
.drv_attrs
= gameport_driver_attrs
;
823 gameport_bus
.match
= gameport_bus_match
;
824 error
= bus_register(&gameport_bus
);
826 printk(KERN_ERR
"gameport: failed to register gameport bus, error: %d\n", error
);
830 gameport_task
= kthread_run(gameport_thread
, NULL
, "kgameportd");
831 if (IS_ERR(gameport_task
)) {
832 bus_unregister(&gameport_bus
);
833 error
= PTR_ERR(gameport_task
);
834 printk(KERN_ERR
"gameport: Failed to start kgameportd, error: %d\n", error
);
841 static void __exit
gameport_exit(void)
843 bus_unregister(&gameport_bus
);
844 kthread_stop(gameport_task
);
847 subsys_initcall(gameport_init
);
848 module_exit(gameport_exit
);