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/slab.h>
21 #include <linux/delay.h>
22 #include <linux/kthread.h>
23 #include <linux/sched.h> /* HZ */
24 #include <linux/mutex.h>
25 #include <linux/freezer.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_set_phys
);
40 EXPORT_SYMBOL(gameport_start_polling
);
41 EXPORT_SYMBOL(gameport_stop_polling
);
44 * gameport_mutex protects entire gameport subsystem and is taken
45 * every time gameport port or driver registrered or unregistered.
47 static DEFINE_MUTEX(gameport_mutex
);
49 static LIST_HEAD(gameport_list
);
51 static struct bus_type gameport_bus
;
53 static void gameport_add_driver(struct gameport_driver
*drv
);
54 static void gameport_add_port(struct gameport
*gameport
);
55 static void gameport_destroy_port(struct gameport
*gameport
);
56 static void gameport_reconnect_port(struct gameport
*gameport
);
57 static void gameport_disconnect_port(struct gameport
*gameport
);
61 #include <asm/i8253.h>
63 #define DELTA(x,y) ((y)-(x)+((y)<(x)?1193182/HZ:0))
64 #define GET_TIME(x) do { x = get_time_pit(); } while (0)
66 static unsigned int get_time_pit(void)
71 spin_lock_irqsave(&i8253_lock
, flags
);
74 count
|= inb_p(0x40) << 8;
75 spin_unlock_irqrestore(&i8253_lock
, flags
);
85 * gameport_measure_speed() measures the gameport i/o speed.
88 static int gameport_measure_speed(struct gameport
*gameport
)
92 unsigned int i
, t
, t1
, t2
, t3
, tx
;
95 if (gameport_open(gameport
, NULL
, GAMEPORT_MODE_RAW
))
100 for(i
= 0; i
< 50; i
++) {
101 local_irq_save(flags
);
103 for (t
= 0; t
< 50; t
++) gameport_read(gameport
);
106 local_irq_restore(flags
);
108 if ((t
= DELTA(t2
,t1
) - DELTA(t3
,t2
)) < tx
) tx
= t
;
111 gameport_close(gameport
);
112 return 59659 / (tx
< 1 ? 1 : tx
);
114 #elif defined (__x86_64__)
117 unsigned long tx
, t1
, t2
, flags
;
119 if (gameport_open(gameport
, NULL
, GAMEPORT_MODE_RAW
))
124 for(i
= 0; i
< 50; i
++) {
125 local_irq_save(flags
);
127 for (t
= 0; t
< 50; t
++) gameport_read(gameport
);
129 local_irq_restore(flags
);
131 if (t2
- t1
< tx
) tx
= t2
- t1
;
134 gameport_close(gameport
);
135 return (cpu_data(raw_smp_processor_id()).loops_per_jiffy
*
136 (unsigned long)HZ
/ (1000 / 50)) / (tx
< 1 ? 1 : tx
);
140 unsigned int j
, t
= 0;
142 if (gameport_open(gameport
, NULL
, GAMEPORT_MODE_RAW
))
145 j
= jiffies
; while (j
== jiffies
);
146 j
= jiffies
; while (j
== jiffies
) { t
++; gameport_read(gameport
); }
148 gameport_close(gameport
);
149 return t
* HZ
/ 1000;
154 void gameport_start_polling(struct gameport
*gameport
)
156 spin_lock(&gameport
->timer_lock
);
158 if (!gameport
->poll_cnt
++) {
159 BUG_ON(!gameport
->poll_handler
);
160 BUG_ON(!gameport
->poll_interval
);
161 mod_timer(&gameport
->poll_timer
, jiffies
+ msecs_to_jiffies(gameport
->poll_interval
));
164 spin_unlock(&gameport
->timer_lock
);
167 void gameport_stop_polling(struct gameport
*gameport
)
169 spin_lock(&gameport
->timer_lock
);
171 if (!--gameport
->poll_cnt
)
172 del_timer(&gameport
->poll_timer
);
174 spin_unlock(&gameport
->timer_lock
);
177 static void gameport_run_poll_handler(unsigned long d
)
179 struct gameport
*gameport
= (struct gameport
*)d
;
181 gameport
->poll_handler(gameport
);
182 if (gameport
->poll_cnt
)
183 mod_timer(&gameport
->poll_timer
, jiffies
+ msecs_to_jiffies(gameport
->poll_interval
));
187 * Basic gameport -> driver core mappings
190 static int gameport_bind_driver(struct gameport
*gameport
, struct gameport_driver
*drv
)
194 gameport
->dev
.driver
= &drv
->driver
;
195 if (drv
->connect(gameport
, drv
)) {
196 gameport
->dev
.driver
= NULL
;
200 error
= device_bind_driver(&gameport
->dev
);
203 "gameport: device_bind_driver() failed "
204 "for %s (%s) and %s, error: %d\n",
205 gameport
->phys
, gameport
->name
,
206 drv
->description
, error
);
207 drv
->disconnect(gameport
);
208 gameport
->dev
.driver
= NULL
;
215 static void gameport_find_driver(struct gameport
*gameport
)
219 error
= device_attach(&gameport
->dev
);
222 "gameport: device_attach() failed for %s (%s), error: %d\n",
223 gameport
->phys
, gameport
->name
, error
);
228 * Gameport event processing.
231 enum gameport_event_type
{
232 GAMEPORT_REGISTER_PORT
,
233 GAMEPORT_REGISTER_DRIVER
,
234 GAMEPORT_ATTACH_DRIVER
,
237 struct gameport_event
{
238 enum gameport_event_type type
;
240 struct module
*owner
;
241 struct list_head node
;
244 static DEFINE_SPINLOCK(gameport_event_lock
); /* protects gameport_event_list */
245 static LIST_HEAD(gameport_event_list
);
246 static DECLARE_WAIT_QUEUE_HEAD(gameport_wait
);
247 static struct task_struct
*gameport_task
;
249 static int gameport_queue_event(void *object
, struct module
*owner
,
250 enum gameport_event_type event_type
)
253 struct gameport_event
*event
;
256 spin_lock_irqsave(&gameport_event_lock
, flags
);
259 * Scan event list for the other events for the same gameport port,
260 * starting with the most recent one. If event is the same we
261 * do not need add new one. If event is of different type we
262 * need to add this event and should not look further because
263 * we need to preseve sequence of distinct events.
265 list_for_each_entry_reverse(event
, &gameport_event_list
, node
) {
266 if (event
->object
== object
) {
267 if (event
->type
== event_type
)
273 event
= kmalloc(sizeof(struct gameport_event
), GFP_ATOMIC
);
276 "gameport: Not enough memory to queue event %d\n",
282 if (!try_module_get(owner
)) {
284 "gameport: Can't get module reference, dropping event %d\n",
291 event
->type
= event_type
;
292 event
->object
= object
;
293 event
->owner
= owner
;
295 list_add_tail(&event
->node
, &gameport_event_list
);
296 wake_up(&gameport_wait
);
299 spin_unlock_irqrestore(&gameport_event_lock
, flags
);
303 static void gameport_free_event(struct gameport_event
*event
)
305 module_put(event
->owner
);
309 static void gameport_remove_duplicate_events(struct gameport_event
*event
)
311 struct list_head
*node
, *next
;
312 struct gameport_event
*e
;
315 spin_lock_irqsave(&gameport_event_lock
, flags
);
317 list_for_each_safe(node
, next
, &gameport_event_list
) {
318 e
= list_entry(node
, struct gameport_event
, node
);
319 if (event
->object
== e
->object
) {
321 * If this event is of different type we should not
322 * look further - we only suppress duplicate events
323 * that were sent back-to-back.
325 if (event
->type
!= e
->type
)
329 gameport_free_event(e
);
333 spin_unlock_irqrestore(&gameport_event_lock
, flags
);
336 static struct gameport_event
*gameport_get_event(void)
338 struct gameport_event
*event
;
339 struct list_head
*node
;
342 spin_lock_irqsave(&gameport_event_lock
, flags
);
344 if (list_empty(&gameport_event_list
)) {
345 spin_unlock_irqrestore(&gameport_event_lock
, flags
);
349 node
= gameport_event_list
.next
;
350 event
= list_entry(node
, struct gameport_event
, node
);
353 spin_unlock_irqrestore(&gameport_event_lock
, flags
);
358 static void gameport_handle_event(void)
360 struct gameport_event
*event
;
362 mutex_lock(&gameport_mutex
);
365 * Note that we handle only one event here to give swsusp
366 * a chance to freeze kgameportd thread. Gameport events
367 * should be pretty rare so we are not concerned about
368 * taking performance hit.
370 if ((event
= gameport_get_event())) {
372 switch (event
->type
) {
373 case GAMEPORT_REGISTER_PORT
:
374 gameport_add_port(event
->object
);
377 case GAMEPORT_REGISTER_DRIVER
:
378 gameport_add_driver(event
->object
);
385 gameport_remove_duplicate_events(event
);
386 gameport_free_event(event
);
389 mutex_unlock(&gameport_mutex
);
393 * Remove all events that have been submitted for a given object,
394 * be it a gameport port or a driver.
396 static void gameport_remove_pending_events(void *object
)
398 struct list_head
*node
, *next
;
399 struct gameport_event
*event
;
402 spin_lock_irqsave(&gameport_event_lock
, flags
);
404 list_for_each_safe(node
, next
, &gameport_event_list
) {
405 event
= list_entry(node
, struct gameport_event
, node
);
406 if (event
->object
== object
) {
408 gameport_free_event(event
);
412 spin_unlock_irqrestore(&gameport_event_lock
, flags
);
416 * Destroy child gameport port (if any) that has not been fully registered yet.
418 * Note that we rely on the fact that port can have only one child and therefore
419 * only one child registration request can be pending. Additionally, children
420 * are registered by driver's connect() handler so there can't be a grandchild
421 * pending registration together with a child.
423 static struct gameport
*gameport_get_pending_child(struct gameport
*parent
)
425 struct gameport_event
*event
;
426 struct gameport
*gameport
, *child
= NULL
;
429 spin_lock_irqsave(&gameport_event_lock
, flags
);
431 list_for_each_entry(event
, &gameport_event_list
, node
) {
432 if (event
->type
== GAMEPORT_REGISTER_PORT
) {
433 gameport
= event
->object
;
434 if (gameport
->parent
== parent
) {
441 spin_unlock_irqrestore(&gameport_event_lock
, flags
);
445 static int gameport_thread(void *nothing
)
449 gameport_handle_event();
450 wait_event_freezable(gameport_wait
,
451 kthread_should_stop() || !list_empty(&gameport_event_list
));
452 } while (!kthread_should_stop());
454 printk(KERN_DEBUG
"gameport: kgameportd exiting\n");
460 * Gameport port operations
463 static ssize_t
gameport_show_description(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
465 struct gameport
*gameport
= to_gameport_port(dev
);
466 return sprintf(buf
, "%s\n", gameport
->name
);
469 static ssize_t
gameport_rebind_driver(struct device
*dev
, struct device_attribute
*attr
, const char *buf
, size_t count
)
471 struct gameport
*gameport
= to_gameport_port(dev
);
472 struct device_driver
*drv
;
475 error
= mutex_lock_interruptible(&gameport_mutex
);
479 if (!strncmp(buf
, "none", count
)) {
480 gameport_disconnect_port(gameport
);
481 } else if (!strncmp(buf
, "reconnect", count
)) {
482 gameport_reconnect_port(gameport
);
483 } else if (!strncmp(buf
, "rescan", count
)) {
484 gameport_disconnect_port(gameport
);
485 gameport_find_driver(gameport
);
486 } else if ((drv
= driver_find(buf
, &gameport_bus
)) != NULL
) {
487 gameport_disconnect_port(gameport
);
488 error
= gameport_bind_driver(gameport
, to_gameport_driver(drv
));
494 mutex_unlock(&gameport_mutex
);
496 return error
? error
: count
;
499 static struct device_attribute gameport_device_attrs
[] = {
500 __ATTR(description
, S_IRUGO
, gameport_show_description
, NULL
),
501 __ATTR(drvctl
, S_IWUSR
, NULL
, gameport_rebind_driver
),
505 static void gameport_release_port(struct device
*dev
)
507 struct gameport
*gameport
= to_gameport_port(dev
);
510 module_put(THIS_MODULE
);
513 void gameport_set_phys(struct gameport
*gameport
, const char *fmt
, ...)
518 vsnprintf(gameport
->phys
, sizeof(gameport
->phys
), fmt
, args
);
523 * Prepare gameport port for registration.
525 static void gameport_init_port(struct gameport
*gameport
)
527 static atomic_t gameport_no
= ATOMIC_INIT(0);
529 __module_get(THIS_MODULE
);
531 mutex_init(&gameport
->drv_mutex
);
532 device_initialize(&gameport
->dev
);
533 dev_set_name(&gameport
->dev
, "gameport%lu", (unsigned long)atomic_inc_return(&gameport_no
) - 1);
534 gameport
->dev
.bus
= &gameport_bus
;
535 gameport
->dev
.release
= gameport_release_port
;
536 if (gameport
->parent
)
537 gameport
->dev
.parent
= &gameport
->parent
->dev
;
539 INIT_LIST_HEAD(&gameport
->node
);
540 spin_lock_init(&gameport
->timer_lock
);
541 init_timer(&gameport
->poll_timer
);
542 gameport
->poll_timer
.function
= gameport_run_poll_handler
;
543 gameport
->poll_timer
.data
= (unsigned long)gameport
;
547 * Complete gameport port registration.
548 * Driver core will attempt to find appropriate driver for the port.
550 static void gameport_add_port(struct gameport
*gameport
)
554 if (gameport
->parent
)
555 gameport
->parent
->child
= gameport
;
557 gameport
->speed
= gameport_measure_speed(gameport
);
559 list_add_tail(&gameport
->node
, &gameport_list
);
562 printk(KERN_INFO
"gameport: %s is %s, io %#x, speed %dkHz\n",
563 gameport
->name
, gameport
->phys
, gameport
->io
, gameport
->speed
);
565 printk(KERN_INFO
"gameport: %s is %s, speed %dkHz\n",
566 gameport
->name
, gameport
->phys
, gameport
->speed
);
568 error
= device_add(&gameport
->dev
);
571 "gameport: device_add() failed for %s (%s), error: %d\n",
572 gameport
->phys
, gameport
->name
, error
);
574 gameport
->registered
= 1;
578 * gameport_destroy_port() completes deregistration process and removes
579 * port from the system
581 static void gameport_destroy_port(struct gameport
*gameport
)
583 struct gameport
*child
;
585 child
= gameport_get_pending_child(gameport
);
587 gameport_remove_pending_events(child
);
588 put_device(&child
->dev
);
591 if (gameport
->parent
) {
592 gameport
->parent
->child
= NULL
;
593 gameport
->parent
= NULL
;
596 if (gameport
->registered
) {
597 device_del(&gameport
->dev
);
598 gameport
->registered
= 0;
601 list_del_init(&gameport
->node
);
603 gameport_remove_pending_events(gameport
);
604 put_device(&gameport
->dev
);
608 * Reconnect gameport port and all its children (re-initialize attached devices)
610 static void gameport_reconnect_port(struct gameport
*gameport
)
613 if (!gameport
->drv
|| !gameport
->drv
->reconnect
|| gameport
->drv
->reconnect(gameport
)) {
614 gameport_disconnect_port(gameport
);
615 gameport_find_driver(gameport
);
616 /* Ok, old children are now gone, we are done */
619 gameport
= gameport
->child
;
624 * gameport_disconnect_port() unbinds a port from its driver. As a side effect
625 * all child ports are unbound and destroyed.
627 static void gameport_disconnect_port(struct gameport
*gameport
)
629 struct gameport
*s
, *parent
;
631 if (gameport
->child
) {
633 * Children ports should be disconnected and destroyed
634 * first, staring with the leaf one, since we don't want
637 for (s
= gameport
; s
->child
; s
= s
->child
)
643 device_release_driver(&s
->dev
);
644 gameport_destroy_port(s
);
645 } while ((s
= parent
) != gameport
);
649 * Ok, no children left, now disconnect this port
651 device_release_driver(&gameport
->dev
);
655 * Submits register request to kgameportd for subsequent execution.
656 * Note that port registration is always asynchronous.
658 void __gameport_register_port(struct gameport
*gameport
, struct module
*owner
)
660 gameport_init_port(gameport
);
661 gameport_queue_event(gameport
, owner
, GAMEPORT_REGISTER_PORT
);
665 * Synchronously unregisters gameport port.
667 void gameport_unregister_port(struct gameport
*gameport
)
669 mutex_lock(&gameport_mutex
);
670 gameport_disconnect_port(gameport
);
671 gameport_destroy_port(gameport
);
672 mutex_unlock(&gameport_mutex
);
677 * Gameport driver operations
680 static ssize_t
gameport_driver_show_description(struct device_driver
*drv
, char *buf
)
682 struct gameport_driver
*driver
= to_gameport_driver(drv
);
683 return sprintf(buf
, "%s\n", driver
->description
? driver
->description
: "(none)");
686 static struct driver_attribute gameport_driver_attrs
[] = {
687 __ATTR(description
, S_IRUGO
, gameport_driver_show_description
, NULL
),
691 static int gameport_driver_probe(struct device
*dev
)
693 struct gameport
*gameport
= to_gameport_port(dev
);
694 struct gameport_driver
*drv
= to_gameport_driver(dev
->driver
);
696 drv
->connect(gameport
, drv
);
697 return gameport
->drv
? 0 : -ENODEV
;
700 static int gameport_driver_remove(struct device
*dev
)
702 struct gameport
*gameport
= to_gameport_port(dev
);
703 struct gameport_driver
*drv
= to_gameport_driver(dev
->driver
);
705 drv
->disconnect(gameport
);
709 static void gameport_add_driver(struct gameport_driver
*drv
)
713 error
= driver_register(&drv
->driver
);
716 "gameport: driver_register() failed for %s, error: %d\n",
717 drv
->driver
.name
, error
);
720 int __gameport_register_driver(struct gameport_driver
*drv
, struct module
*owner
,
721 const char *mod_name
)
725 drv
->driver
.bus
= &gameport_bus
;
726 drv
->driver
.owner
= owner
;
727 drv
->driver
.mod_name
= mod_name
;
730 * Temporarily disable automatic binding because probing
731 * takes long time and we are better off doing it in kgameportd
735 error
= driver_register(&drv
->driver
);
738 "gameport: driver_register() failed for %s, error: %d\n",
739 drv
->driver
.name
, error
);
744 * Reset ignore flag and let kgameportd bind the driver to free ports
747 error
= gameport_queue_event(drv
, NULL
, GAMEPORT_ATTACH_DRIVER
);
749 driver_unregister(&drv
->driver
);
756 void gameport_unregister_driver(struct gameport_driver
*drv
)
758 struct gameport
*gameport
;
760 mutex_lock(&gameport_mutex
);
762 drv
->ignore
= 1; /* so gameport_find_driver ignores it */
763 gameport_remove_pending_events(drv
);
766 list_for_each_entry(gameport
, &gameport_list
, node
) {
767 if (gameport
->drv
== drv
) {
768 gameport_disconnect_port(gameport
);
769 gameport_find_driver(gameport
);
770 /* we could've deleted some ports, restart */
775 driver_unregister(&drv
->driver
);
777 mutex_unlock(&gameport_mutex
);
780 static int gameport_bus_match(struct device
*dev
, struct device_driver
*drv
)
782 struct gameport_driver
*gameport_drv
= to_gameport_driver(drv
);
784 return !gameport_drv
->ignore
;
787 static struct bus_type gameport_bus
= {
789 .dev_attrs
= gameport_device_attrs
,
790 .drv_attrs
= gameport_driver_attrs
,
791 .match
= gameport_bus_match
,
792 .probe
= gameport_driver_probe
,
793 .remove
= gameport_driver_remove
,
796 static void gameport_set_drv(struct gameport
*gameport
, struct gameport_driver
*drv
)
798 mutex_lock(&gameport
->drv_mutex
);
800 mutex_unlock(&gameport
->drv_mutex
);
803 int gameport_open(struct gameport
*gameport
, struct gameport_driver
*drv
, int mode
)
805 if (gameport
->open
) {
806 if (gameport
->open(gameport
, mode
)) {
810 if (mode
!= GAMEPORT_MODE_RAW
)
814 gameport_set_drv(gameport
, drv
);
818 void gameport_close(struct gameport
*gameport
)
820 del_timer_sync(&gameport
->poll_timer
);
821 gameport
->poll_handler
= NULL
;
822 gameport
->poll_interval
= 0;
823 gameport_set_drv(gameport
, NULL
);
825 gameport
->close(gameport
);
828 static int __init
gameport_init(void)
832 error
= bus_register(&gameport_bus
);
834 printk(KERN_ERR
"gameport: failed to register gameport bus, error: %d\n", error
);
838 gameport_task
= kthread_run(gameport_thread
, NULL
, "kgameportd");
839 if (IS_ERR(gameport_task
)) {
840 bus_unregister(&gameport_bus
);
841 error
= PTR_ERR(gameport_task
);
842 printk(KERN_ERR
"gameport: Failed to start kgameportd, error: %d\n", error
);
849 static void __exit
gameport_exit(void)
851 bus_unregister(&gameport_bus
);
852 kthread_stop(gameport_task
);
855 subsys_initcall(gameport_init
);
856 module_exit(gameport_exit
);