2 * The Serio abstraction module
4 * Copyright (c) 1999-2004 Vojtech Pavlik
5 * Copyright (c) 2004 Dmitry Torokhov
6 * Copyright (c) 2003 Daniele Bellucci
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
24 * Should you need to contact me, the author, you can do so either by
25 * e-mail - mail your message to <vojtech@ucw.cz>, or by paper mail:
26 * Vojtech Pavlik, Simunkova 1594, Prague 8, 182 00 Czech Republic
29 #include <linux/stddef.h>
30 #include <linux/module.h>
31 #include <linux/serio.h>
32 #include <linux/errno.h>
33 #include <linux/wait.h>
34 #include <linux/completion.h>
35 #include <linux/sched.h>
36 #include <linux/smp_lock.h>
37 #include <linux/slab.h>
39 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
40 MODULE_DESCRIPTION("Serio abstraction core");
41 MODULE_LICENSE("GPL");
43 EXPORT_SYMBOL(serio_interrupt);
44 EXPORT_SYMBOL(__serio_register_port);
45 EXPORT_SYMBOL(serio_unregister_port);
46 EXPORT_SYMBOL(__serio_unregister_port_delayed);
47 EXPORT_SYMBOL(__serio_register_driver);
48 EXPORT_SYMBOL(serio_unregister_driver);
49 EXPORT_SYMBOL(serio_open);
50 EXPORT_SYMBOL(serio_close);
51 EXPORT_SYMBOL(serio_rescan);
52 EXPORT_SYMBOL(serio_reconnect);
55 * serio_sem protects entire serio subsystem and is taken every time
56 * serio port or driver registrered or unregistered.
58 static DECLARE_MUTEX(serio_sem);
60 static LIST_HEAD(serio_list);
62 static struct bus_type serio_bus = {
66 static void serio_add_port(struct serio *serio);
67 static void serio_destroy_port(struct serio *serio);
68 static void serio_reconnect_port(struct serio *serio);
69 static void serio_disconnect_port(struct serio *serio);
71 static int serio_match_port(const struct serio_device_id *ids, struct serio *serio)
73 while (ids->type || ids->proto) {
74 if ((ids->type == SERIO_ANY || ids->type == serio->id.type) &&
75 (ids->proto == SERIO_ANY || ids->proto == serio->id.proto) &&
76 (ids->extra == SERIO_ANY || ids->extra == serio->id.extra) &&
77 (ids->id == SERIO_ANY || ids->id == serio->id.id))
85 * Basic serio -> driver core mappings
88 static void serio_bind_driver(struct serio *serio, struct serio_driver *drv)
90 down_write(&serio_bus.subsys.rwsem);
92 if (serio_match_port(drv->id_table, serio)) {
93 serio->dev.driver = &drv->driver;
94 if (drv->connect(serio, drv)) {
95 serio->dev.driver = NULL;
98 device_bind_driver(&serio->dev);
101 up_write(&serio_bus.subsys.rwsem);
104 static void serio_release_driver(struct serio *serio)
106 down_write(&serio_bus.subsys.rwsem);
107 device_release_driver(&serio->dev);
108 up_write(&serio_bus.subsys.rwsem);
111 static void serio_find_driver(struct serio *serio)
113 down_write(&serio_bus.subsys.rwsem);
114 device_attach(&serio->dev);
115 up_write(&serio_bus.subsys.rwsem);
120 * Serio event processing.
123 enum serio_event_type {
127 SERIO_UNREGISTER_PORT,
128 SERIO_REGISTER_DRIVER,
132 enum serio_event_type type;
134 struct module *owner;
135 struct list_head node;
138 static DEFINE_SPINLOCK(serio_event_lock); /* protects serio_event_list */
139 static LIST_HEAD(serio_event_list);
140 static DECLARE_WAIT_QUEUE_HEAD(serio_wait);
141 static DECLARE_COMPLETION(serio_exited);
142 static int serio_pid;
144 static void serio_queue_event(void *object, struct module *owner,
145 enum serio_event_type event_type)
148 struct serio_event *event;
150 spin_lock_irqsave(&serio_event_lock, flags);
153 * Scan event list for the other events for the same serio port,
154 * starting with the most recent one. If event is the same we
155 * do not need add new one. If event is of different type we
156 * need to add this event and should not look further because
157 * we need to preseve sequence of distinct events.
159 list_for_each_entry_reverse(event, &serio_event_list, node) {
160 if (event->object == object) {
161 if (event->type == event_type)
167 if ((event = kmalloc(sizeof(struct serio_event), GFP_ATOMIC))) {
168 if (!try_module_get(owner)) {
169 printk(KERN_WARNING "serio: Can't get module reference, dropping event %d\n", event_type);
173 event->type = event_type;
174 event->object = object;
175 event->owner = owner;
177 list_add_tail(&event->node, &serio_event_list);
178 wake_up(&serio_wait);
180 printk(KERN_ERR "serio: Not enough memory to queue event %d\n", event_type);
183 spin_unlock_irqrestore(&serio_event_lock, flags);
186 static void serio_free_event(struct serio_event *event)
188 module_put(event->owner);
192 static void serio_remove_duplicate_events(struct serio_event *event)
194 struct list_head *node, *next;
195 struct serio_event *e;
198 spin_lock_irqsave(&serio_event_lock, flags);
200 list_for_each_safe(node, next, &serio_event_list) {
201 e = list_entry(node, struct serio_event, node);
202 if (event->object == e->object) {
204 * If this event is of different type we should not
205 * look further - we only suppress duplicate events
206 * that were sent back-to-back.
208 if (event->type != e->type)
216 spin_unlock_irqrestore(&serio_event_lock, flags);
220 static struct serio_event *serio_get_event(void)
222 struct serio_event *event;
223 struct list_head *node;
226 spin_lock_irqsave(&serio_event_lock, flags);
228 if (list_empty(&serio_event_list)) {
229 spin_unlock_irqrestore(&serio_event_lock, flags);
233 node = serio_event_list.next;
234 event = list_entry(node, struct serio_event, node);
237 spin_unlock_irqrestore(&serio_event_lock, flags);
242 static void serio_handle_events(void)
244 struct serio_event *event;
245 struct serio_driver *serio_drv;
249 while ((event = serio_get_event())) {
251 switch (event->type) {
252 case SERIO_REGISTER_PORT:
253 serio_add_port(event->object);
256 case SERIO_UNREGISTER_PORT:
257 serio_disconnect_port(event->object);
258 serio_destroy_port(event->object);
261 case SERIO_RECONNECT:
262 serio_reconnect_port(event->object);
266 serio_disconnect_port(event->object);
267 serio_find_driver(event->object);
270 case SERIO_REGISTER_DRIVER:
271 serio_drv = event->object;
272 driver_register(&serio_drv->driver);
279 serio_remove_duplicate_events(event);
280 serio_free_event(event);
287 * Remove all events that have been submitted for a given serio port.
289 static void serio_remove_pending_events(struct serio *serio)
291 struct list_head *node, *next;
292 struct serio_event *event;
295 spin_lock_irqsave(&serio_event_lock, flags);
297 list_for_each_safe(node, next, &serio_event_list) {
298 event = list_entry(node, struct serio_event, node);
299 if (event->object == serio) {
301 serio_free_event(event);
305 spin_unlock_irqrestore(&serio_event_lock, flags);
309 * Destroy child serio port (if any) that has not been fully registered yet.
311 * Note that we rely on the fact that port can have only one child and therefore
312 * only one child registration request can be pending. Additionally, children
313 * are registered by driver's connect() handler so there can't be a grandchild
314 * pending registration together with a child.
316 static struct serio *serio_get_pending_child(struct serio *parent)
318 struct serio_event *event;
319 struct serio *serio, *child = NULL;
322 spin_lock_irqsave(&serio_event_lock, flags);
324 list_for_each_entry(event, &serio_event_list, node) {
325 if (event->type == SERIO_REGISTER_PORT) {
326 serio = event->object;
327 if (serio->parent == parent) {
334 spin_unlock_irqrestore(&serio_event_lock, flags);
338 static int serio_thread(void *nothing)
341 daemonize("kseriod");
342 allow_signal(SIGTERM);
345 serio_handle_events();
346 wait_event_interruptible(serio_wait, !list_empty(&serio_event_list));
347 try_to_freeze(PF_FREEZE);
348 } while (!signal_pending(current));
350 printk(KERN_DEBUG "serio: kseriod exiting\n");
353 complete_and_exit(&serio_exited, 0);
358 * Serio port operations
361 static ssize_t serio_show_description(struct device *dev, char *buf)
363 struct serio *serio = to_serio_port(dev);
364 return sprintf(buf, "%s\n", serio->name);
367 static ssize_t serio_show_id_type(struct device *dev, char *buf)
369 struct serio *serio = to_serio_port(dev);
370 return sprintf(buf, "%02x\n", serio->id.type);
373 static ssize_t serio_show_id_proto(struct device *dev, char *buf)
375 struct serio *serio = to_serio_port(dev);
376 return sprintf(buf, "%02x\n", serio->id.proto);
379 static ssize_t serio_show_id_id(struct device *dev, char *buf)
381 struct serio *serio = to_serio_port(dev);
382 return sprintf(buf, "%02x\n", serio->id.id);
385 static ssize_t serio_show_id_extra(struct device *dev, char *buf)
387 struct serio *serio = to_serio_port(dev);
388 return sprintf(buf, "%02x\n", serio->id.extra);
391 static ssize_t serio_rebind_driver(struct device *dev, const char *buf, size_t count)
393 struct serio *serio = to_serio_port(dev);
394 struct device_driver *drv;
397 retval = down_interruptible(&serio_sem);
402 if (!strncmp(buf, "none", count)) {
403 serio_disconnect_port(serio);
404 } else if (!strncmp(buf, "reconnect", count)) {
405 serio_reconnect_port(serio);
406 } else if (!strncmp(buf, "rescan", count)) {
407 serio_disconnect_port(serio);
408 serio_find_driver(serio);
409 } else if ((drv = driver_find(buf, &serio_bus)) != NULL) {
410 serio_disconnect_port(serio);
411 serio_bind_driver(serio, to_serio_driver(drv));
422 static ssize_t serio_show_bind_mode(struct device *dev, char *buf)
424 struct serio *serio = to_serio_port(dev);
425 return sprintf(buf, "%s\n", serio->manual_bind ? "manual" : "auto");
428 static ssize_t serio_set_bind_mode(struct device *dev, const char *buf, size_t count)
430 struct serio *serio = to_serio_port(dev);
434 if (!strncmp(buf, "manual", count)) {
435 serio->manual_bind = 1;
436 } else if (!strncmp(buf, "auto", count)) {
437 serio->manual_bind = 0;
445 static struct device_attribute serio_device_attrs[] = {
446 __ATTR(description, S_IRUGO, serio_show_description, NULL),
447 __ATTR(id_type, S_IRUGO, serio_show_id_type, NULL),
448 __ATTR(id_proto, S_IRUGO, serio_show_id_proto, NULL),
449 __ATTR(id_id, S_IRUGO, serio_show_id_id, NULL),
450 __ATTR(id_extra, S_IRUGO, serio_show_id_extra, NULL),
451 __ATTR(drvctl, S_IWUSR, NULL, serio_rebind_driver),
452 __ATTR(bind_mode, S_IWUSR | S_IRUGO, serio_show_bind_mode, serio_set_bind_mode),
457 static void serio_release_port(struct device *dev)
459 struct serio *serio = to_serio_port(dev);
462 module_put(THIS_MODULE);
466 * Prepare serio port for registration.
468 static void serio_init_port(struct serio *serio)
470 static atomic_t serio_no = ATOMIC_INIT(0);
472 __module_get(THIS_MODULE);
474 spin_lock_init(&serio->lock);
475 init_MUTEX(&serio->drv_sem);
476 device_initialize(&serio->dev);
477 snprintf(serio->dev.bus_id, sizeof(serio->dev.bus_id),
478 "serio%ld", (long)atomic_inc_return(&serio_no) - 1);
479 serio->dev.bus = &serio_bus;
480 serio->dev.release = serio_release_port;
482 serio->dev.parent = &serio->parent->dev;
486 * Complete serio port registration.
487 * Driver core will attempt to find appropriate driver for the port.
489 static void serio_add_port(struct serio *serio)
492 serio_pause_rx(serio->parent);
493 serio->parent->child = serio;
494 serio_continue_rx(serio->parent);
497 list_add_tail(&serio->node, &serio_list);
500 device_add(&serio->dev);
501 serio->registered = 1;
505 * serio_destroy_port() completes deregistration process and removes
506 * port from the system
508 static void serio_destroy_port(struct serio *serio)
512 child = serio_get_pending_child(serio);
514 serio_remove_pending_events(child);
515 put_device(&child->dev);
522 serio_pause_rx(serio->parent);
523 serio->parent->child = NULL;
524 serio_continue_rx(serio->parent);
525 serio->parent = NULL;
528 if (serio->registered) {
529 device_del(&serio->dev);
530 list_del_init(&serio->node);
531 serio->registered = 0;
534 serio_remove_pending_events(serio);
535 put_device(&serio->dev);
539 * Reconnect serio port and all its children (re-initialize attached devices)
541 static void serio_reconnect_port(struct serio *serio)
544 if (!serio->drv || !serio->drv->reconnect || serio->drv->reconnect(serio)) {
545 serio_disconnect_port(serio);
546 serio_find_driver(serio);
547 /* Ok, old children are now gone, we are done */
550 serio = serio->child;
555 * serio_disconnect_port() unbinds a port from its driver. As a side effect
556 * all child ports are unbound and destroyed.
558 static void serio_disconnect_port(struct serio *serio)
560 struct serio *s, *parent;
564 * Children ports should be disconnected and destroyed
565 * first, staring with the leaf one, since we don't want
568 for (s = serio; s->child; s = s->child)
574 serio_release_driver(s);
575 serio_destroy_port(s);
576 } while ((s = parent) != serio);
580 * Ok, no children left, now disconnect this port
582 serio_release_driver(serio);
585 void serio_rescan(struct serio *serio)
587 serio_queue_event(serio, NULL, SERIO_RESCAN);
590 void serio_reconnect(struct serio *serio)
592 serio_queue_event(serio, NULL, SERIO_RECONNECT);
596 * Submits register request to kseriod for subsequent execution.
597 * Note that port registration is always asynchronous.
599 void __serio_register_port(struct serio *serio, struct module *owner)
601 serio_init_port(serio);
602 serio_queue_event(serio, owner, SERIO_REGISTER_PORT);
606 * Synchronously unregisters serio port.
608 void serio_unregister_port(struct serio *serio)
611 serio_disconnect_port(serio);
612 serio_destroy_port(serio);
617 * Submits register request to kseriod for subsequent execution.
618 * Can be used when it is not obvious whether the serio_sem is
619 * taken or not and when delayed execution is feasible.
621 void __serio_unregister_port_delayed(struct serio *serio, struct module *owner)
623 serio_queue_event(serio, owner, SERIO_UNREGISTER_PORT);
628 * Serio driver operations
631 static ssize_t serio_driver_show_description(struct device_driver *drv, char *buf)
633 struct serio_driver *driver = to_serio_driver(drv);
634 return sprintf(buf, "%s\n", driver->description ? driver->description : "(none)");
637 static ssize_t serio_driver_show_bind_mode(struct device_driver *drv, char *buf)
639 struct serio_driver *serio_drv = to_serio_driver(drv);
640 return sprintf(buf, "%s\n", serio_drv->manual_bind ? "manual" : "auto");
643 static ssize_t serio_driver_set_bind_mode(struct device_driver *drv, const char *buf, size_t count)
645 struct serio_driver *serio_drv = to_serio_driver(drv);
649 if (!strncmp(buf, "manual", count)) {
650 serio_drv->manual_bind = 1;
651 } else if (!strncmp(buf, "auto", count)) {
652 serio_drv->manual_bind = 0;
661 static struct driver_attribute serio_driver_attrs[] = {
662 __ATTR(description, S_IRUGO, serio_driver_show_description, NULL),
663 __ATTR(bind_mode, S_IWUSR | S_IRUGO,
664 serio_driver_show_bind_mode, serio_driver_set_bind_mode),
668 static int serio_driver_probe(struct device *dev)
670 struct serio *serio = to_serio_port(dev);
671 struct serio_driver *drv = to_serio_driver(dev->driver);
673 return drv->connect(serio, drv);
676 static int serio_driver_remove(struct device *dev)
678 struct serio *serio = to_serio_port(dev);
679 struct serio_driver *drv = to_serio_driver(dev->driver);
681 drv->disconnect(serio);
685 void __serio_register_driver(struct serio_driver *drv, struct module *owner)
687 drv->driver.bus = &serio_bus;
688 drv->driver.probe = serio_driver_probe;
689 drv->driver.remove = serio_driver_remove;
691 serio_queue_event(drv, owner, SERIO_REGISTER_DRIVER);
694 void serio_unregister_driver(struct serio_driver *drv)
699 drv->manual_bind = 1; /* so serio_find_driver ignores it */
702 list_for_each_entry(serio, &serio_list, node) {
703 if (serio->drv == drv) {
704 serio_disconnect_port(serio);
705 serio_find_driver(serio);
706 /* we could've deleted some ports, restart */
711 driver_unregister(&drv->driver);
715 static void serio_set_drv(struct serio *serio, struct serio_driver *drv)
717 down(&serio->drv_sem);
718 serio_pause_rx(serio);
720 serio_continue_rx(serio);
724 static int serio_bus_match(struct device *dev, struct device_driver *drv)
726 struct serio *serio = to_serio_port(dev);
727 struct serio_driver *serio_drv = to_serio_driver(drv);
729 if (serio->manual_bind || serio_drv->manual_bind)
732 return serio_match_port(serio_drv->id_table, serio);
735 #ifdef CONFIG_HOTPLUG
737 #define PUT_ENVP(fmt, val) \
739 envp[i++] = buffer; \
740 length += snprintf(buffer, buffer_size - length, fmt, val); \
741 if (buffer_size - length <= 0 || i >= num_envp) \
746 static int serio_hotplug(struct device *dev, char **envp, int num_envp, char *buffer, int buffer_size)
755 serio = to_serio_port(dev);
757 PUT_ENVP("SERIO_TYPE=%02x", serio->id.type);
758 PUT_ENVP("SERIO_PROTO=%02x", serio->id.proto);
759 PUT_ENVP("SERIO_ID=%02x", serio->id.id);
760 PUT_ENVP("SERIO_EXTRA=%02x", serio->id.extra);
770 static int serio_hotplug(struct device *dev, char **envp, int num_envp, char *buffer, int buffer_size)
775 #endif /* CONFIG_HOTPLUG */
777 static int serio_resume(struct device *dev)
779 struct serio *serio = to_serio_port(dev);
781 if (!serio->drv || !serio->drv->reconnect || serio->drv->reconnect(serio)) {
782 serio_disconnect_port(serio);
784 * Driver re-probing can take a while, so better let kseriod
793 /* called from serio_driver->connect/disconnect methods under serio_sem */
794 int serio_open(struct serio *serio, struct serio_driver *drv)
796 serio_set_drv(serio, drv);
798 if (serio->open && serio->open(serio)) {
799 serio_set_drv(serio, NULL);
805 /* called from serio_driver->connect/disconnect methods under serio_sem */
806 void serio_close(struct serio *serio)
811 serio_set_drv(serio, NULL);
814 irqreturn_t serio_interrupt(struct serio *serio,
815 unsigned char data, unsigned int dfl, struct pt_regs *regs)
818 irqreturn_t ret = IRQ_NONE;
820 spin_lock_irqsave(&serio->lock, flags);
822 if (likely(serio->drv)) {
823 ret = serio->drv->interrupt(serio, data, dfl, regs);
824 } else if (!dfl && serio->registered) {
829 spin_unlock_irqrestore(&serio->lock, flags);
834 static int __init serio_init(void)
836 if (!(serio_pid = kernel_thread(serio_thread, NULL, CLONE_KERNEL))) {
837 printk(KERN_ERR "serio: Failed to start kseriod\n");
841 serio_bus.dev_attrs = serio_device_attrs;
842 serio_bus.drv_attrs = serio_driver_attrs;
843 serio_bus.match = serio_bus_match;
844 serio_bus.hotplug = serio_hotplug;
845 serio_bus.resume = serio_resume;
846 bus_register(&serio_bus);
851 static void __exit serio_exit(void)
853 bus_unregister(&serio_bus);
854 kill_proc(serio_pid, SIGTERM, 1);
855 wait_for_completion(&serio_exited);
858 module_init(serio_init);
859 module_exit(serio_exit);