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/sched.h>
35 #include <linux/slab.h>
36 #include <linux/kthread.h>
38 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
39 MODULE_DESCRIPTION("Serio abstraction core");
40 MODULE_LICENSE("GPL");
42 EXPORT_SYMBOL(serio_interrupt);
43 EXPORT_SYMBOL(__serio_register_port);
44 EXPORT_SYMBOL(serio_unregister_port);
45 EXPORT_SYMBOL(serio_unregister_child_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;
64 static void serio_add_port(struct serio *serio);
65 static void serio_destroy_port(struct serio *serio);
66 static void serio_reconnect_port(struct serio *serio);
67 static void serio_disconnect_port(struct serio *serio);
69 static int serio_connect_driver(struct serio *serio, struct serio_driver *drv)
73 down(&serio->drv_sem);
74 retval = drv->connect(serio, drv);
80 static int serio_reconnect_driver(struct serio *serio)
84 down(&serio->drv_sem);
85 if (serio->drv && serio->drv->reconnect)
86 retval = serio->drv->reconnect(serio);
92 static void serio_disconnect_driver(struct serio *serio)
94 down(&serio->drv_sem);
96 serio->drv->disconnect(serio);
100 static int serio_match_port(const struct serio_device_id *ids, struct serio *serio)
102 while (ids->type || ids->proto) {
103 if ((ids->type == SERIO_ANY || ids->type == serio->id.type) &&
104 (ids->proto == SERIO_ANY || ids->proto == serio->id.proto) &&
105 (ids->extra == SERIO_ANY || ids->extra == serio->id.extra) &&
106 (ids->id == SERIO_ANY || ids->id == serio->id.id))
114 * Basic serio -> driver core mappings
117 static void serio_bind_driver(struct serio *serio, struct serio_driver *drv)
119 down_write(&serio_bus.subsys.rwsem);
121 if (serio_match_port(drv->id_table, serio)) {
122 serio->dev.driver = &drv->driver;
123 if (serio_connect_driver(serio, drv)) {
124 serio->dev.driver = NULL;
127 device_bind_driver(&serio->dev);
130 up_write(&serio_bus.subsys.rwsem);
133 static void serio_release_driver(struct serio *serio)
135 down_write(&serio_bus.subsys.rwsem);
136 device_release_driver(&serio->dev);
137 up_write(&serio_bus.subsys.rwsem);
140 static void serio_find_driver(struct serio *serio)
142 down_write(&serio_bus.subsys.rwsem);
143 device_attach(&serio->dev);
144 up_write(&serio_bus.subsys.rwsem);
149 * Serio event processing.
152 enum serio_event_type {
156 SERIO_UNREGISTER_PORT,
157 SERIO_REGISTER_DRIVER,
161 enum serio_event_type type;
163 struct module *owner;
164 struct list_head node;
167 static DEFINE_SPINLOCK(serio_event_lock); /* protects serio_event_list */
168 static LIST_HEAD(serio_event_list);
169 static DECLARE_WAIT_QUEUE_HEAD(serio_wait);
170 static struct task_struct *serio_task;
172 static void serio_queue_event(void *object, struct module *owner,
173 enum serio_event_type event_type)
176 struct serio_event *event;
178 spin_lock_irqsave(&serio_event_lock, flags);
181 * Scan event list for the other events for the same serio port,
182 * starting with the most recent one. If event is the same we
183 * do not need add new one. If event is of different type we
184 * need to add this event and should not look further because
185 * we need to preseve sequence of distinct events.
187 list_for_each_entry_reverse(event, &serio_event_list, node) {
188 if (event->object == object) {
189 if (event->type == event_type)
195 if ((event = kmalloc(sizeof(struct serio_event), GFP_ATOMIC))) {
196 if (!try_module_get(owner)) {
197 printk(KERN_WARNING "serio: Can't get module reference, dropping event %d\n", event_type);
201 event->type = event_type;
202 event->object = object;
203 event->owner = owner;
205 list_add_tail(&event->node, &serio_event_list);
206 wake_up(&serio_wait);
208 printk(KERN_ERR "serio: Not enough memory to queue event %d\n", event_type);
211 spin_unlock_irqrestore(&serio_event_lock, flags);
214 static void serio_free_event(struct serio_event *event)
216 module_put(event->owner);
220 static void serio_remove_duplicate_events(struct serio_event *event)
222 struct list_head *node, *next;
223 struct serio_event *e;
226 spin_lock_irqsave(&serio_event_lock, flags);
228 list_for_each_safe(node, next, &serio_event_list) {
229 e = list_entry(node, struct serio_event, node);
230 if (event->object == e->object) {
232 * If this event is of different type we should not
233 * look further - we only suppress duplicate events
234 * that were sent back-to-back.
236 if (event->type != e->type)
244 spin_unlock_irqrestore(&serio_event_lock, flags);
248 static struct serio_event *serio_get_event(void)
250 struct serio_event *event;
251 struct list_head *node;
254 spin_lock_irqsave(&serio_event_lock, flags);
256 if (list_empty(&serio_event_list)) {
257 spin_unlock_irqrestore(&serio_event_lock, flags);
261 node = serio_event_list.next;
262 event = list_entry(node, struct serio_event, node);
265 spin_unlock_irqrestore(&serio_event_lock, flags);
270 static void serio_handle_event(void)
272 struct serio_event *event;
273 struct serio_driver *serio_drv;
278 * Note that we handle only one event here to give swsusp
279 * a chance to freeze kseriod thread. Serio events should
280 * be pretty rare so we are not concerned about taking
283 if ((event = serio_get_event())) {
285 switch (event->type) {
286 case SERIO_REGISTER_PORT:
287 serio_add_port(event->object);
290 case SERIO_UNREGISTER_PORT:
291 serio_disconnect_port(event->object);
292 serio_destroy_port(event->object);
295 case SERIO_RECONNECT:
296 serio_reconnect_port(event->object);
300 serio_disconnect_port(event->object);
301 serio_find_driver(event->object);
304 case SERIO_REGISTER_DRIVER:
305 serio_drv = event->object;
306 driver_register(&serio_drv->driver);
313 serio_remove_duplicate_events(event);
314 serio_free_event(event);
321 * Remove all events that have been submitted for a given serio port.
323 static void serio_remove_pending_events(struct serio *serio)
325 struct list_head *node, *next;
326 struct serio_event *event;
329 spin_lock_irqsave(&serio_event_lock, flags);
331 list_for_each_safe(node, next, &serio_event_list) {
332 event = list_entry(node, struct serio_event, node);
333 if (event->object == serio) {
335 serio_free_event(event);
339 spin_unlock_irqrestore(&serio_event_lock, flags);
343 * Destroy child serio port (if any) that has not been fully registered yet.
345 * Note that we rely on the fact that port can have only one child and therefore
346 * only one child registration request can be pending. Additionally, children
347 * are registered by driver's connect() handler so there can't be a grandchild
348 * pending registration together with a child.
350 static struct serio *serio_get_pending_child(struct serio *parent)
352 struct serio_event *event;
353 struct serio *serio, *child = NULL;
356 spin_lock_irqsave(&serio_event_lock, flags);
358 list_for_each_entry(event, &serio_event_list, node) {
359 if (event->type == SERIO_REGISTER_PORT) {
360 serio = event->object;
361 if (serio->parent == parent) {
368 spin_unlock_irqrestore(&serio_event_lock, flags);
372 static int serio_thread(void *nothing)
375 serio_handle_event();
376 wait_event_interruptible(serio_wait,
377 kthread_should_stop() || !list_empty(&serio_event_list));
379 } while (!kthread_should_stop());
381 printk(KERN_DEBUG "serio: kseriod exiting\n");
387 * Serio port operations
390 static ssize_t serio_show_description(struct device *dev, struct device_attribute *attr, char *buf)
392 struct serio *serio = to_serio_port(dev);
393 return sprintf(buf, "%s\n", serio->name);
396 static ssize_t serio_show_modalias(struct device *dev, struct device_attribute *attr, char *buf)
398 struct serio *serio = to_serio_port(dev);
400 return sprintf(buf, "serio:ty%02Xpr%02Xid%02Xex%02X\n",
401 serio->id.type, serio->id.proto, serio->id.id, serio->id.extra);
404 static ssize_t serio_show_id_type(struct device *dev, struct device_attribute *attr, char *buf)
406 struct serio *serio = to_serio_port(dev);
407 return sprintf(buf, "%02x\n", serio->id.type);
410 static ssize_t serio_show_id_proto(struct device *dev, struct device_attribute *attr, char *buf)
412 struct serio *serio = to_serio_port(dev);
413 return sprintf(buf, "%02x\n", serio->id.proto);
416 static ssize_t serio_show_id_id(struct device *dev, struct device_attribute *attr, char *buf)
418 struct serio *serio = to_serio_port(dev);
419 return sprintf(buf, "%02x\n", serio->id.id);
422 static ssize_t serio_show_id_extra(struct device *dev, struct device_attribute *attr, char *buf)
424 struct serio *serio = to_serio_port(dev);
425 return sprintf(buf, "%02x\n", serio->id.extra);
428 static DEVICE_ATTR(type, S_IRUGO, serio_show_id_type, NULL);
429 static DEVICE_ATTR(proto, S_IRUGO, serio_show_id_proto, NULL);
430 static DEVICE_ATTR(id, S_IRUGO, serio_show_id_id, NULL);
431 static DEVICE_ATTR(extra, S_IRUGO, serio_show_id_extra, NULL);
433 static struct attribute *serio_device_id_attrs[] = {
435 &dev_attr_proto.attr,
437 &dev_attr_extra.attr,
441 static struct attribute_group serio_id_attr_group = {
443 .attrs = serio_device_id_attrs,
446 static ssize_t serio_rebind_driver(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
448 struct serio *serio = to_serio_port(dev);
449 struct device_driver *drv;
452 retval = down_interruptible(&serio_sem);
457 if (!strncmp(buf, "none", count)) {
458 serio_disconnect_port(serio);
459 } else if (!strncmp(buf, "reconnect", count)) {
460 serio_reconnect_port(serio);
461 } else if (!strncmp(buf, "rescan", count)) {
462 serio_disconnect_port(serio);
463 serio_find_driver(serio);
464 } else if ((drv = driver_find(buf, &serio_bus)) != NULL) {
465 serio_disconnect_port(serio);
466 serio_bind_driver(serio, to_serio_driver(drv));
477 static ssize_t serio_show_bind_mode(struct device *dev, struct device_attribute *attr, char *buf)
479 struct serio *serio = to_serio_port(dev);
480 return sprintf(buf, "%s\n", serio->manual_bind ? "manual" : "auto");
483 static ssize_t serio_set_bind_mode(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
485 struct serio *serio = to_serio_port(dev);
489 if (!strncmp(buf, "manual", count)) {
490 serio->manual_bind = 1;
491 } else if (!strncmp(buf, "auto", count)) {
492 serio->manual_bind = 0;
500 static struct device_attribute serio_device_attrs[] = {
501 __ATTR(description, S_IRUGO, serio_show_description, NULL),
502 __ATTR(modalias, S_IRUGO, serio_show_modalias, NULL),
503 __ATTR(drvctl, S_IWUSR, NULL, serio_rebind_driver),
504 __ATTR(bind_mode, S_IWUSR | S_IRUGO, serio_show_bind_mode, serio_set_bind_mode),
509 static void serio_release_port(struct device *dev)
511 struct serio *serio = to_serio_port(dev);
514 module_put(THIS_MODULE);
518 * Prepare serio port for registration.
520 static void serio_init_port(struct serio *serio)
522 static atomic_t serio_no = ATOMIC_INIT(0);
524 __module_get(THIS_MODULE);
526 spin_lock_init(&serio->lock);
527 init_MUTEX(&serio->drv_sem);
528 device_initialize(&serio->dev);
529 snprintf(serio->dev.bus_id, sizeof(serio->dev.bus_id),
530 "serio%ld", (long)atomic_inc_return(&serio_no) - 1);
531 serio->dev.bus = &serio_bus;
532 serio->dev.release = serio_release_port;
534 serio->dev.parent = &serio->parent->dev;
538 * Complete serio port registration.
539 * Driver core will attempt to find appropriate driver for the port.
541 static void serio_add_port(struct serio *serio)
544 serio_pause_rx(serio->parent);
545 serio->parent->child = serio;
546 serio_continue_rx(serio->parent);
549 list_add_tail(&serio->node, &serio_list);
552 device_add(&serio->dev);
553 sysfs_create_group(&serio->dev.kobj, &serio_id_attr_group);
554 serio->registered = 1;
558 * serio_destroy_port() completes deregistration process and removes
559 * port from the system
561 static void serio_destroy_port(struct serio *serio)
565 child = serio_get_pending_child(serio);
567 serio_remove_pending_events(child);
568 put_device(&child->dev);
575 serio_pause_rx(serio->parent);
576 serio->parent->child = NULL;
577 serio_continue_rx(serio->parent);
578 serio->parent = NULL;
581 if (serio->registered) {
582 sysfs_remove_group(&serio->dev.kobj, &serio_id_attr_group);
583 device_del(&serio->dev);
584 list_del_init(&serio->node);
585 serio->registered = 0;
588 serio_remove_pending_events(serio);
589 put_device(&serio->dev);
593 * Reconnect serio port and all its children (re-initialize attached devices)
595 static void serio_reconnect_port(struct serio *serio)
598 if (serio_reconnect_driver(serio)) {
599 serio_disconnect_port(serio);
600 serio_find_driver(serio);
601 /* Ok, old children are now gone, we are done */
604 serio = serio->child;
609 * serio_disconnect_port() unbinds a port from its driver. As a side effect
610 * all child ports are unbound and destroyed.
612 static void serio_disconnect_port(struct serio *serio)
614 struct serio *s, *parent;
618 * Children ports should be disconnected and destroyed
619 * first, staring with the leaf one, since we don't want
622 for (s = serio; s->child; s = s->child)
628 serio_release_driver(s);
629 serio_destroy_port(s);
630 } while ((s = parent) != serio);
634 * Ok, no children left, now disconnect this port
636 serio_release_driver(serio);
639 void serio_rescan(struct serio *serio)
641 serio_queue_event(serio, NULL, SERIO_RESCAN);
644 void serio_reconnect(struct serio *serio)
646 serio_queue_event(serio, NULL, SERIO_RECONNECT);
650 * Submits register request to kseriod for subsequent execution.
651 * Note that port registration is always asynchronous.
653 void __serio_register_port(struct serio *serio, struct module *owner)
655 serio_init_port(serio);
656 serio_queue_event(serio, owner, SERIO_REGISTER_PORT);
660 * Synchronously unregisters serio port.
662 void serio_unregister_port(struct serio *serio)
665 serio_disconnect_port(serio);
666 serio_destroy_port(serio);
671 * Safely unregisters child port if one is present.
673 void serio_unregister_child_port(struct serio *serio)
677 serio_disconnect_port(serio->child);
678 serio_destroy_port(serio->child);
684 * Submits register request to kseriod for subsequent execution.
685 * Can be used when it is not obvious whether the serio_sem is
686 * taken or not and when delayed execution is feasible.
688 void __serio_unregister_port_delayed(struct serio *serio, struct module *owner)
690 serio_queue_event(serio, owner, SERIO_UNREGISTER_PORT);
695 * Serio driver operations
698 static ssize_t serio_driver_show_description(struct device_driver *drv, char *buf)
700 struct serio_driver *driver = to_serio_driver(drv);
701 return sprintf(buf, "%s\n", driver->description ? driver->description : "(none)");
704 static ssize_t serio_driver_show_bind_mode(struct device_driver *drv, char *buf)
706 struct serio_driver *serio_drv = to_serio_driver(drv);
707 return sprintf(buf, "%s\n", serio_drv->manual_bind ? "manual" : "auto");
710 static ssize_t serio_driver_set_bind_mode(struct device_driver *drv, const char *buf, size_t count)
712 struct serio_driver *serio_drv = to_serio_driver(drv);
716 if (!strncmp(buf, "manual", count)) {
717 serio_drv->manual_bind = 1;
718 } else if (!strncmp(buf, "auto", count)) {
719 serio_drv->manual_bind = 0;
728 static struct driver_attribute serio_driver_attrs[] = {
729 __ATTR(description, S_IRUGO, serio_driver_show_description, NULL),
730 __ATTR(bind_mode, S_IWUSR | S_IRUGO,
731 serio_driver_show_bind_mode, serio_driver_set_bind_mode),
735 static int serio_driver_probe(struct device *dev)
737 struct serio *serio = to_serio_port(dev);
738 struct serio_driver *drv = to_serio_driver(dev->driver);
740 return serio_connect_driver(serio, drv);
743 static int serio_driver_remove(struct device *dev)
745 struct serio *serio = to_serio_port(dev);
747 serio_disconnect_driver(serio);
751 static struct bus_type serio_bus = {
753 .probe = serio_driver_probe,
754 .remove = serio_driver_remove,
757 void __serio_register_driver(struct serio_driver *drv, struct module *owner)
759 drv->driver.bus = &serio_bus;
761 serio_queue_event(drv, owner, SERIO_REGISTER_DRIVER);
764 void serio_unregister_driver(struct serio_driver *drv)
769 drv->manual_bind = 1; /* so serio_find_driver ignores it */
772 list_for_each_entry(serio, &serio_list, node) {
773 if (serio->drv == drv) {
774 serio_disconnect_port(serio);
775 serio_find_driver(serio);
776 /* we could've deleted some ports, restart */
781 driver_unregister(&drv->driver);
785 static void serio_set_drv(struct serio *serio, struct serio_driver *drv)
787 serio_pause_rx(serio);
789 serio_continue_rx(serio);
792 static int serio_bus_match(struct device *dev, struct device_driver *drv)
794 struct serio *serio = to_serio_port(dev);
795 struct serio_driver *serio_drv = to_serio_driver(drv);
797 if (serio->manual_bind || serio_drv->manual_bind)
800 return serio_match_port(serio_drv->id_table, serio);
803 #ifdef CONFIG_HOTPLUG
805 #define SERIO_ADD_UEVENT_VAR(fmt, val...) \
807 int err = add_uevent_var(envp, num_envp, &i, \
808 buffer, buffer_size, &len, \
814 static int serio_uevent(struct device *dev, char **envp, int num_envp, char *buffer, int buffer_size)
823 serio = to_serio_port(dev);
825 SERIO_ADD_UEVENT_VAR("SERIO_TYPE=%02x", serio->id.type);
826 SERIO_ADD_UEVENT_VAR("SERIO_PROTO=%02x", serio->id.proto);
827 SERIO_ADD_UEVENT_VAR("SERIO_ID=%02x", serio->id.id);
828 SERIO_ADD_UEVENT_VAR("SERIO_EXTRA=%02x", serio->id.extra);
829 SERIO_ADD_UEVENT_VAR("MODALIAS=serio:ty%02Xpr%02Xid%02Xex%02X",
830 serio->id.type, serio->id.proto, serio->id.id, serio->id.extra);
835 #undef SERIO_ADD_UEVENT_VAR
839 static int serio_uevent(struct device *dev, char **envp, int num_envp, char *buffer, int buffer_size)
844 #endif /* CONFIG_HOTPLUG */
846 static int serio_resume(struct device *dev)
848 struct serio *serio = to_serio_port(dev);
850 if (serio_reconnect_driver(serio)) {
852 * Driver re-probing can take a while, so better let kseriod
861 /* called from serio_driver->connect/disconnect methods under serio_sem */
862 int serio_open(struct serio *serio, struct serio_driver *drv)
864 serio_set_drv(serio, drv);
866 if (serio->open && serio->open(serio)) {
867 serio_set_drv(serio, NULL);
873 /* called from serio_driver->connect/disconnect methods under serio_sem */
874 void serio_close(struct serio *serio)
879 serio_set_drv(serio, NULL);
882 irqreturn_t serio_interrupt(struct serio *serio,
883 unsigned char data, unsigned int dfl, struct pt_regs *regs)
886 irqreturn_t ret = IRQ_NONE;
888 spin_lock_irqsave(&serio->lock, flags);
890 if (likely(serio->drv)) {
891 ret = serio->drv->interrupt(serio, data, dfl, regs);
892 } else if (!dfl && serio->registered) {
897 spin_unlock_irqrestore(&serio->lock, flags);
902 static int __init serio_init(void)
904 serio_task = kthread_run(serio_thread, NULL, "kseriod");
905 if (IS_ERR(serio_task)) {
906 printk(KERN_ERR "serio: Failed to start kseriod\n");
907 return PTR_ERR(serio_task);
910 serio_bus.dev_attrs = serio_device_attrs;
911 serio_bus.drv_attrs = serio_driver_attrs;
912 serio_bus.match = serio_bus_match;
913 serio_bus.uevent = serio_uevent;
914 serio_bus.resume = serio_resume;
915 bus_register(&serio_bus);
920 static void __exit serio_exit(void)
922 bus_unregister(&serio_bus);
923 kthread_stop(serio_task);
926 module_init(serio_init);
927 module_exit(serio_exit);