/* * Generic gameport layer * * Copyright (c) 1999-2002 Vojtech Pavlik * Copyright (c) 2005 Dmitry Torokhov */ /* * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 as published by * the Free Software Foundation. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include #include #include #include #include #include #include #include #include #include /* HZ */ #include #include /*#include */ MODULE_AUTHOR("Vojtech Pavlik "); MODULE_DESCRIPTION("Generic gameport layer"); MODULE_LICENSE("GPL"); /* * gameport_mutex protects entire gameport subsystem and is taken * every time gameport port or driver registrered or unregistered. */ static DEFINE_MUTEX(gameport_mutex); static LIST_HEAD(gameport_list); static struct bus_type gameport_bus; static void gameport_add_port(struct gameport *gameport); static void gameport_attach_driver(struct gameport_driver *drv); static void gameport_reconnect_port(struct gameport *gameport); static void gameport_disconnect_port(struct gameport *gameport); #if defined(__i386__) #include #define DELTA(x,y) ((y)-(x)+((y)<(x)?1193182/HZ:0)) #define GET_TIME(x) do { x = get_time_pit(); } while (0) static unsigned int get_time_pit(void) { unsigned long flags; unsigned int count; raw_spin_lock_irqsave(&i8253_lock, flags); outb_p(0x00, 0x43); count = inb_p(0x40); count |= inb_p(0x40) << 8; raw_spin_unlock_irqrestore(&i8253_lock, flags); return count; } #endif /* * gameport_measure_speed() measures the gameport i/o speed. */ static int gameport_measure_speed(struct gameport *gameport) { #if defined(__i386__) unsigned int i, t, t1, t2, t3, tx; unsigned long flags; if (gameport_open(gameport, NULL, GAMEPORT_MODE_RAW)) return 0; tx = 1 << 30; for(i = 0; i < 50; i++) { local_irq_save(flags); GET_TIME(t1); for (t = 0; t < 50; t++) gameport_read(gameport); GET_TIME(t2); GET_TIME(t3); local_irq_restore(flags); udelay(i * 10); if ((t = DELTA(t2,t1) - DELTA(t3,t2)) < tx) tx = t; } gameport_close(gameport); return 59659 / (tx < 1 ? 1 : tx); #elif defined (__x86_64__) unsigned int i, t; unsigned long tx, t1, t2, flags; if (gameport_open(gameport, NULL, GAMEPORT_MODE_RAW)) return 0; tx = 1 << 30; for(i = 0; i < 50; i++) { local_irq_save(flags); rdtscl(t1); for (t = 0; t < 50; t++) gameport_read(gameport); rdtscl(t2); local_irq_restore(flags); udelay(i * 10); if (t2 - t1 < tx) tx = t2 - t1; } gameport_close(gameport); return (this_cpu_read(cpu_info.loops_per_jiffy) * (unsigned long)HZ / (1000 / 50)) / (tx < 1 ? 1 : tx); #else unsigned int j, t = 0; if (gameport_open(gameport, NULL, GAMEPORT_MODE_RAW)) return 0; j = jiffies; while (j == jiffies); j = jiffies; while (j == jiffies) { t++; gameport_read(gameport); } gameport_close(gameport); return t * HZ / 1000; #endif } void gameport_start_polling(struct gameport *gameport) { spin_lock(&gameport->timer_lock); if (!gameport->poll_cnt++) { BUG_ON(!gameport->poll_handler); BUG_ON(!gameport->poll_interval); mod_timer(&gameport->poll_timer, jiffies + msecs_to_jiffies(gameport->poll_interval)); } spin_unlock(&gameport->timer_lock); } EXPORT_SYMBOL(gameport_start_polling); void gameport_stop_polling(struct gameport *gameport) { spin_lock(&gameport->timer_lock); if (!--gameport->poll_cnt) del_timer(&gameport->poll_timer); spin_unlock(&gameport->timer_lock); } EXPORT_SYMBOL(gameport_stop_polling); static void gameport_run_poll_handler(unsigned long d) { struct gameport *gameport = (struct gameport *)d; gameport->poll_handler(gameport); if (gameport->poll_cnt) mod_timer(&gameport->poll_timer, jiffies + msecs_to_jiffies(gameport->poll_interval)); } /* * Basic gameport -> driver core mappings */ static int gameport_bind_driver(struct gameport *gameport, struct gameport_driver *drv) { int error; gameport->dev.driver = &drv->driver; if (drv->connect(gameport, drv)) { gameport->dev.driver = NULL; return -ENODEV; } error = device_bind_driver(&gameport->dev); if (error) { dev_warn(&gameport->dev, "device_bind_driver() failed for %s (%s) and %s, error: %d\n", gameport->phys, gameport->name, drv->description, error); drv->disconnect(gameport); gameport->dev.driver = NULL; return error; } return 0; } static void gameport_find_driver(struct gameport *gameport) { int error; error = device_attach(&gameport->dev); if (error < 0) dev_warn(&gameport->dev, "device_attach() failed for %s (%s), error: %d\n", gameport->phys, gameport->name, error); } /* * Gameport event processing. */ enum gameport_event_type { GAMEPORT_REGISTER_PORT, GAMEPORT_ATTACH_DRIVER, }; struct gameport_event { enum gameport_event_type type; void *object; struct module *owner; struct list_head node; }; static DEFINE_SPINLOCK(gameport_event_lock); /* protects gameport_event_list */ static LIST_HEAD(gameport_event_list); static DECLARE_WAIT_QUEUE_HEAD(gameport_wait); static struct task_struct *gameport_task; static int gameport_queue_event(void *object, struct module *owner, enum gameport_event_type event_type) { unsigned long flags; struct gameport_event *event; int retval = 0; spin_lock_irqsave(&gameport_event_lock, flags); /* * Scan event list for the other events for the same gameport port, * starting with the most recent one. If event is the same we * do not need add new one. If event is of different type we * need to add this event and should not look further because * we need to preseve sequence of distinct events. */ list_for_each_entry_reverse(event, &gameport_event_list, node) { if (event->object == object) { if (event->type == event_type) goto out; break; } } event = kmalloc(sizeof(struct gameport_event), GFP_ATOMIC); if (!event) { pr_err("Not enough memory to queue event %d\n", event_type); retval = -ENOMEM; goto out; } if (!try_module_get(owner)) { pr_warning("Can't get module reference, dropping event %d\n", event_type); kfree(event); retval = -EINVAL; goto out; } event->type = event_type; event->object = object; event->owner = owner; list_add_tail(&event->node, &gameport_event_list); wake_up(&gameport_wait); out: spin_unlock_irqrestore(&gameport_event_lock, flags); return retval; } static void gameport_free_event(struct gameport_event *event) { module_put(event->owner); kfree(event); } static void gameport_remove_duplicate_events(struct gameport_event *event) { struct gameport_event *e, *next; unsigned long flags; spin_lock_irqsave(&gameport_event_lock, flags); list_for_each_entry_safe(e, next, &gameport_event_list, node) { if (event->object == e->object) { /* * If this event is of different type we should not * look further - we only suppress duplicate events * that were sent back-to-back. */ if (event->type != e->type) break; list_del_init(&e->node); gameport_free_event(e); } } spin_unlock_irqrestore(&gameport_event_lock, flags); } static struct gameport_event *gameport_get_event(void) { struct gameport_event *event = NULL; unsigned long flags; spin_lock_irqsave(&gameport_event_lock, flags); if (!list_empty(&gameport_event_list)) { event = list_first_entry(&gameport_event_list, struct gameport_event, node); list_del_init(&event->node); } spin_unlock_irqrestore(&gameport_event_lock, flags); return event; } static void gameport_handle_event(void) { struct gameport_event *event; mutex_lock(&gameport_mutex); /* * Note that we handle only one event here to give swsusp * a chance to freeze kgameportd thread. Gameport events * should be pretty rare so we are not concerned about * taking performance hit. */ if ((event = gameport_get_event())) { switch (event->type) { case GAMEPORT_REGISTER_PORT: gameport_add_port(event->object); break; case GAMEPORT_ATTACH_DRIVER: gameport_attach_driver(event->object); break; } gameport_remove_duplicate_events(event); gameport_free_event(event); } mutex_unlock(&gameport_mutex); } /* * Remove all events that have been submitted for a given object, * be it a gameport port or a driver. */ static void gameport_remove_pending_events(void *object) { struct gameport_event *event, *next; unsigned long flags; spin_lock_irqsave(&gameport_event_lock, flags); list_for_each_entry_safe(event, next, &gameport_event_list, node) { if (event->object == object) { list_del_init(&event->node); gameport_free_event(event); } } spin_unlock_irqrestore(&gameport_event_lock, flags); } /* * Destroy child gameport port (if any) that has not been fully registered yet. * * Note that we rely on the fact that port can have only one child and therefore * only one child registration request can be pending. Additionally, children * are registered by driver's connect() handler so there can't be a grandchild * pending registration together with a child. */ static struct gameport *gameport_get_pending_child(struct gameport *parent) { struct gameport_event *event; struct gameport *gameport, *child = NULL; unsigned long flags; spin_lock_irqsave(&gameport_event_lock, flags); list_for_each_entry(event, &gameport_event_list, node) { if (event->type == GAMEPORT_REGISTER_PORT) { gameport = event->object; if (gameport->parent == parent) { child = gameport; break; } } } spin_unlock_irqrestore(&gameport_event_lock, flags); return child; } static int gameport_thread(void *nothing) { set_freezable(); do { gameport_handle_event(); wait_event_freezable(gameport_wait, kthread_should_stop() || !list_empty(&gameport_event_list)); } while (!kthread_should_stop()); return 0; } /* * Gameport port operations */ static ssize_t gameport_show_description(struct device *dev, struct device_attribute *attr, char *buf) { struct gameport *gameport = to_gameport_port(dev); return sprintf(buf, "%s\n", gameport->name); } static ssize_t gameport_rebind_driver(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct gameport *gameport = to_gameport_port(dev); struct device_driver *drv; int error; error = mutex_lock_interruptible(&gameport_mutex); if (error) return error; if (!strncmp(buf, "none", count)) { gameport_disconnect_port(gameport); } else if (!strncmp(buf, "reconnect", count)) { gameport_reconnect_port(gameport); } else if (!strncmp(buf, "rescan", count)) { gameport_disconnect_port(gameport); gameport_find_driver(gameport); } else if ((drv = driver_find(buf, &gameport_bus)) != NULL) { gameport_disconnect_port(gameport); error = gameport_bind_driver(gameport, to_gameport_driver(drv)); put_driver(drv); } else { error = -EINVAL; } mutex_unlock(&gameport_mutex); return error ? error : count; } static struct device_attribute gameport_device_attrs[] = { __ATTR(description, S_IRUGO, gameport_show_description, NULL), __ATTR(drvctl, S_IWUSR, NULL, gameport_rebind_driver), __ATTR_NULL }; static void gameport_release_port(struct device *dev) { struct gameport *gameport = to_gameport_port(dev); kfree(gameport); module_put(THIS_MODULE); } void gameport_set_phys(struct gameport *gameport, const char *fmt, ...) { va_list args; va_start(args, fmt); vsnprintf(gameport->phys, sizeof(gameport->phys), fmt, args); va_end(args); } EXPORT_SYMBOL(gameport_set_phys); /* * Prepare gameport port for registration. */ static void gameport_init_port(struct gameport *gameport) { static atomic_t gameport_no = ATOMIC_INIT(0); __module_get(THIS_MODULE); mutex_init(&gameport->drv_mutex); device_initialize(&gameport->dev); dev_set_name(&gameport->dev, "gameport%lu", (unsigned long)atomic_inc_return(&gameport_no) - 1); gameport->dev.bus = &gameport_bus; gameport->dev.release = gameport_release_port; if (gameport->parent) gameport->dev.parent = &gameport->parent->dev; INIT_LIST_HEAD(&gameport->node); spin_lock_init(&gameport->timer_lock); init_timer(&gameport->poll_timer); gameport->poll_timer.function = gameport_run_poll_handler; gameport->poll_timer.data = (unsigned long)gameport; } /* * Complete gameport port registration. * Driver core will attempt to find appropriate driver for the port. */ static void gameport_add_port(struct gameport *gameport) { int error; if (gameport->parent) gameport->parent->child = gameport; gameport->speed = gameport_measure_speed(gameport); list_add_tail(&gameport->node, &gameport_list); if (gameport->io) dev_info(&gameport->dev, "%s is %s, io %#x, speed %dkHz\n", gameport->name, gameport->phys, gameport->io, gameport->speed); else dev_info(&gameport->dev, "%s is %s, speed %dkHz\n", gameport->name, gameport->phys, gameport->speed); error = device_add(&gameport->dev); if (error) dev_err(&gameport->dev, "device_add() failed for %s (%s), error: %d\n", gameport->phys, gameport->name, error); } /* * gameport_destroy_port() completes deregistration process and removes * port from the system */ static void gameport_destroy_port(struct gameport *gameport) { struct gameport *child; child = gameport_get_pending_child(gameport); if (child) { gameport_remove_pending_events(child); put_device(&child->dev); } if (gameport->parent) { gameport->parent->child = NULL; gameport->parent = NULL; } if (device_is_registered(&gameport->dev)) device_del(&gameport->dev); list_del_init(&gameport->node); gameport_remove_pending_events(gameport); put_device(&gameport->dev); } /* * Reconnect gameport port and all its children (re-initialize attached devices) */ static void gameport_reconnect_port(struct gameport *gameport) { do { if (!gameport->drv || !gameport->drv->reconnect || gameport->drv->reconnect(gameport)) { gameport_disconnect_port(gameport); gameport_find_driver(gameport); /* Ok, old children are now gone, we are done */ break; } gameport = gameport->child; } while (gameport); } /* * gameport_disconnect_port() unbinds a port from its driver. As a side effect * all child ports are unbound and destroyed. */ static void gameport_disconnect_port(struct gameport *gameport) { struct gameport *s, *parent; if (gameport->child) { /* * Children ports should be disconnected and destroyed * first, staring with the leaf one, since we don't want * to do recursion */ for (s = gameport; s->child; s = s->child) /* empty */; do { parent = s->parent; device_release_driver(&s->dev); gameport_destroy_port(s); } while ((s = parent) != gameport); } /* * Ok, no children left, now disconnect this port */ device_release_driver(&gameport->dev); } /* * Submits register request to kgameportd for subsequent execution. * Note that port registration is always asynchronous. */ void __gameport_register_port(struct gameport *gameport, struct module *owner) { gameport_init_port(gameport); gameport_queue_event(gameport, owner, GAMEPORT_REGISTER_PORT); } EXPORT_SYMBOL(__gameport_register_port); /* * Synchronously unregisters gameport port. */ void gameport_unregister_port(struct gameport *gameport) { mutex_lock(&gameport_mutex); gameport_disconnect_port(gameport); gameport_destroy_port(gameport); mutex_unlock(&gameport_mutex); } EXPORT_SYMBOL(gameport_unregister_port); /* * Gameport driver operations */ static ssize_t gameport_driver_show_description(struct device_driver *drv, char *buf) { struct gameport_driver *driver = to_gameport_driver(drv); return sprintf(buf, "%s\n", driver->description ? driver->description : "(none)"); } static struct driver_attribute gameport_driver_attrs[] = { __ATTR(description, S_IRUGO, gameport_driver_show_description, NULL), __ATTR_NULL }; static int gameport_driver_probe(struct device *dev) { struct gameport *gameport = to_gameport_port(dev); struct gameport_driver *drv = to_gameport_driver(dev->driver); drv->connect(gameport, drv); return gameport->drv ? 0 : -ENODEV; } static int gameport_driver_remove(struct device *dev) { struct gameport *gameport = to_gameport_port(dev); struct gameport_driver *drv = to_gameport_driver(dev->driver); drv->disconnect(gameport); return 0; } static void gameport_attach_driver(struct gameport_driver *drv) { int error; error = driver_attach(&drv->driver); if (error) pr_err("driver_attach() failed for %s, error: %d\n", drv->driver.name, error); } int __gameport_register_driver(struct gameport_driver *drv, struct module *owner, const char *mod_name) { int error; drv->driver.bus = &gameport_bus; drv->driver.owner = owner; drv->driver.mod_name = mod_name; /* * Temporarily disable automatic binding because probing * takes long time and we are better off doing it in kgameportd */ drv->ignore = true; error = driver_register(&drv->driver); if (error) { pr_err("driver_register() failed for %s, error: %d\n", drv->driver.name, error); return error; } /* * Reset ignore flag and let kgameportd bind the driver to free ports */ drv->ignore = false; error = gameport_queue_event(drv, NULL, GAMEPORT_ATTACH_DRIVER); if (error) { driver_unregister(&drv->driver); return error; } return 0; } EXPORT_SYMBOL(__gameport_register_driver); void gameport_unregister_driver(struct gameport_driver *drv) { struct gameport *gameport; mutex_lock(&gameport_mutex); drv->ignore = true; /* so gameport_find_driver ignores it */ gameport_remove_pending_events(drv); start_over: list_for_each_entry(gameport, &gameport_list, node) { if (gameport->drv == drv) { gameport_disconnect_port(gameport); gameport_find_driver(gameport); /* we could've deleted some ports, restart */ goto start_over; } } driver_unregister(&drv->driver); mutex_unlock(&gameport_mutex); } EXPORT_SYMBOL(gameport_unregister_driver); static int gameport_bus_match(struct device *dev, struct device_driver *drv) { struct gameport_driver *gameport_drv = to_gameport_driver(drv); return !gameport_drv->ignore; } static struct bus_type gameport_bus = { .name = "gameport", .dev_attrs = gameport_device_attrs, .drv_attrs = gameport_driver_attrs, .match = gameport_bus_match, .probe = gameport_driver_probe, .remove = gameport_driver_remove, }; static void gameport_set_drv(struct gameport *gameport, struct gameport_driver *drv) { mutex_lock(&gameport->drv_mutex); gameport->drv = drv; mutex_unlock(&gameport->drv_mutex); } int gameport_open(struct gameport *gameport, struct gameport_driver *drv, int mode) { if (gameport->open) { if (gameport->open(gameport, mode)) { return -1; } } else { if (mode != GAMEPORT_MODE_RAW) return -1; } gameport_set_drv(gameport, drv); return 0; } EXPORT_SYMBOL(gameport_open); void gameport_close(struct gameport *gameport) { del_timer_sync(&gameport->poll_timer); gameport->poll_handler = NULL; gameport->poll_interval = 0; gameport_set_drv(gameport, NULL); if (gameport->close) gameport->close(gameport); } EXPORT_SYMBOL(gameport_close); static int __init gameport_init(void) { int error; error = bus_register(&gameport_bus); if (error) { pr_err("failed to register gameport bus, error: %d\n", error); return error; } gameport_task = kthread_run(gameport_thread, NULL, "kgameportd"); if (IS_ERR(gameport_task)) { bus_unregister(&gameport_bus); error = PTR_ERR(gameport_task); pr_err("Failed to start kgameportd, error: %d\n", error); return error; } return 0; } static void __exit gameport_exit(void) { bus_unregister(&gameport_bus); kthread_stop(gameport_task); } subsys_initcall(gameport_init); module_exit(gameport_exit);