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>
37 #include <linux/mutex.h>
38 #include <linux/freezer.h>
40 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
41 MODULE_DESCRIPTION("Serio abstraction core");
42 MODULE_LICENSE("GPL");
44 EXPORT_SYMBOL(serio_interrupt);
45 EXPORT_SYMBOL(__serio_register_port);
46 EXPORT_SYMBOL(serio_unregister_port);
47 EXPORT_SYMBOL(serio_unregister_child_port);
48 EXPORT_SYMBOL(__serio_register_driver);
49 EXPORT_SYMBOL(serio_unregister_driver);
50 EXPORT_SYMBOL(serio_open);
51 EXPORT_SYMBOL(serio_close);
52 EXPORT_SYMBOL(serio_rescan);
53 EXPORT_SYMBOL(serio_reconnect);
56 * serio_mutex protects entire serio subsystem and is taken every time
57 * serio port or driver registrered or unregistered.
59 static DEFINE_MUTEX(serio_mutex);
61 static LIST_HEAD(serio_list);
63 static struct bus_type serio_bus;
65 static void serio_add_port(struct serio *serio);
66 static void serio_reconnect_port(struct serio *serio);
67 static void serio_disconnect_port(struct serio *serio);
68 static void serio_attach_driver(struct serio_driver *drv);
70 static int serio_connect_driver(struct serio *serio, struct serio_driver *drv)
74 mutex_lock(&serio->drv_mutex);
75 retval = drv->connect(serio, drv);
76 mutex_unlock(&serio->drv_mutex);
81 static int serio_reconnect_driver(struct serio *serio)
85 mutex_lock(&serio->drv_mutex);
86 if (serio->drv && serio->drv->reconnect)
87 retval = serio->drv->reconnect(serio);
88 mutex_unlock(&serio->drv_mutex);
93 static void serio_disconnect_driver(struct serio *serio)
95 mutex_lock(&serio->drv_mutex);
97 serio->drv->disconnect(serio);
98 mutex_unlock(&serio->drv_mutex);
101 static int serio_match_port(const struct serio_device_id *ids, struct serio *serio)
103 while (ids->type || ids->proto) {
104 if ((ids->type == SERIO_ANY || ids->type == serio->id.type) &&
105 (ids->proto == SERIO_ANY || ids->proto == serio->id.proto) &&
106 (ids->extra == SERIO_ANY || ids->extra == serio->id.extra) &&
107 (ids->id == SERIO_ANY || ids->id == serio->id.id))
115 * Basic serio -> driver core mappings
118 static int serio_bind_driver(struct serio *serio, struct serio_driver *drv)
122 if (serio_match_port(drv->id_table, serio)) {
124 serio->dev.driver = &drv->driver;
125 if (serio_connect_driver(serio, drv)) {
126 serio->dev.driver = NULL;
130 error = device_bind_driver(&serio->dev);
133 "serio: device_bind_driver() failed "
134 "for %s (%s) and %s, error: %d\n",
135 serio->phys, serio->name,
136 drv->description, error);
137 serio_disconnect_driver(serio);
138 serio->dev.driver = NULL;
145 static void serio_find_driver(struct serio *serio)
149 error = device_attach(&serio->dev);
152 "serio: device_attach() failed for %s (%s), error: %d\n",
153 serio->phys, serio->name, error);
158 * Serio event processing.
161 enum serio_event_type {
163 SERIO_RECONNECT_PORT,
169 enum serio_event_type type;
171 struct module *owner;
172 struct list_head node;
175 static DEFINE_SPINLOCK(serio_event_lock); /* protects serio_event_list */
176 static LIST_HEAD(serio_event_list);
177 static DECLARE_WAIT_QUEUE_HEAD(serio_wait);
178 static struct task_struct *serio_task;
180 static int serio_queue_event(void *object, struct module *owner,
181 enum serio_event_type event_type)
184 struct serio_event *event;
187 spin_lock_irqsave(&serio_event_lock, flags);
190 * Scan event list for the other events for the same serio port,
191 * starting with the most recent one. If event is the same we
192 * do not need add new one. If event is of different type we
193 * need to add this event and should not look further because
194 * we need to preseve sequence of distinct events.
196 list_for_each_entry_reverse(event, &serio_event_list, node) {
197 if (event->object == object) {
198 if (event->type == event_type)
204 event = kmalloc(sizeof(struct serio_event), GFP_ATOMIC);
207 "serio: Not enough memory to queue event %d\n",
213 if (!try_module_get(owner)) {
215 "serio: Can't get module reference, dropping event %d\n",
222 event->type = event_type;
223 event->object = object;
224 event->owner = owner;
226 list_add_tail(&event->node, &serio_event_list);
227 wake_up(&serio_wait);
230 spin_unlock_irqrestore(&serio_event_lock, flags);
234 static void serio_free_event(struct serio_event *event)
236 module_put(event->owner);
240 static void serio_remove_duplicate_events(struct serio_event *event)
242 struct list_head *node, *next;
243 struct serio_event *e;
246 spin_lock_irqsave(&serio_event_lock, flags);
248 list_for_each_safe(node, next, &serio_event_list) {
249 e = list_entry(node, struct serio_event, node);
250 if (event->object == e->object) {
252 * If this event is of different type we should not
253 * look further - we only suppress duplicate events
254 * that were sent back-to-back.
256 if (event->type != e->type)
264 spin_unlock_irqrestore(&serio_event_lock, flags);
268 static struct serio_event *serio_get_event(void)
270 struct serio_event *event;
271 struct list_head *node;
274 spin_lock_irqsave(&serio_event_lock, flags);
276 if (list_empty(&serio_event_list)) {
277 spin_unlock_irqrestore(&serio_event_lock, flags);
281 node = serio_event_list.next;
282 event = list_entry(node, struct serio_event, node);
285 spin_unlock_irqrestore(&serio_event_lock, flags);
290 static void serio_handle_event(void)
292 struct serio_event *event;
294 mutex_lock(&serio_mutex);
297 * Note that we handle only one event here to give swsusp
298 * a chance to freeze kseriod thread. Serio events should
299 * be pretty rare so we are not concerned about taking
302 if ((event = serio_get_event())) {
304 switch (event->type) {
305 case SERIO_REGISTER_PORT:
306 serio_add_port(event->object);
309 case SERIO_RECONNECT_PORT:
310 serio_reconnect_port(event->object);
313 case SERIO_RESCAN_PORT:
314 serio_disconnect_port(event->object);
315 serio_find_driver(event->object);
318 case SERIO_ATTACH_DRIVER:
319 serio_attach_driver(event->object);
326 serio_remove_duplicate_events(event);
327 serio_free_event(event);
330 mutex_unlock(&serio_mutex);
334 * Remove all events that have been submitted for a given
335 * object, be it serio port or driver.
337 static void serio_remove_pending_events(void *object)
339 struct list_head *node, *next;
340 struct serio_event *event;
343 spin_lock_irqsave(&serio_event_lock, flags);
345 list_for_each_safe(node, next, &serio_event_list) {
346 event = list_entry(node, struct serio_event, node);
347 if (event->object == object) {
349 serio_free_event(event);
353 spin_unlock_irqrestore(&serio_event_lock, flags);
357 * Destroy child serio port (if any) that has not been fully registered yet.
359 * Note that we rely on the fact that port can have only one child and therefore
360 * only one child registration request can be pending. Additionally, children
361 * are registered by driver's connect() handler so there can't be a grandchild
362 * pending registration together with a child.
364 static struct serio *serio_get_pending_child(struct serio *parent)
366 struct serio_event *event;
367 struct serio *serio, *child = NULL;
370 spin_lock_irqsave(&serio_event_lock, flags);
372 list_for_each_entry(event, &serio_event_list, node) {
373 if (event->type == SERIO_REGISTER_PORT) {
374 serio = event->object;
375 if (serio->parent == parent) {
382 spin_unlock_irqrestore(&serio_event_lock, flags);
386 static int serio_thread(void *nothing)
390 serio_handle_event();
391 wait_event_freezable(serio_wait,
392 kthread_should_stop() || !list_empty(&serio_event_list));
393 } while (!kthread_should_stop());
395 printk(KERN_DEBUG "serio: kseriod exiting\n");
401 * Serio port operations
404 static ssize_t serio_show_description(struct device *dev, struct device_attribute *attr, char *buf)
406 struct serio *serio = to_serio_port(dev);
407 return sprintf(buf, "%s\n", serio->name);
410 static ssize_t serio_show_modalias(struct device *dev, struct device_attribute *attr, char *buf)
412 struct serio *serio = to_serio_port(dev);
414 return sprintf(buf, "serio:ty%02Xpr%02Xid%02Xex%02X\n",
415 serio->id.type, serio->id.proto, serio->id.id, serio->id.extra);
418 static ssize_t serio_show_id_type(struct device *dev, struct device_attribute *attr, char *buf)
420 struct serio *serio = to_serio_port(dev);
421 return sprintf(buf, "%02x\n", serio->id.type);
424 static ssize_t serio_show_id_proto(struct device *dev, struct device_attribute *attr, char *buf)
426 struct serio *serio = to_serio_port(dev);
427 return sprintf(buf, "%02x\n", serio->id.proto);
430 static ssize_t serio_show_id_id(struct device *dev, struct device_attribute *attr, char *buf)
432 struct serio *serio = to_serio_port(dev);
433 return sprintf(buf, "%02x\n", serio->id.id);
436 static ssize_t serio_show_id_extra(struct device *dev, struct device_attribute *attr, char *buf)
438 struct serio *serio = to_serio_port(dev);
439 return sprintf(buf, "%02x\n", serio->id.extra);
442 static DEVICE_ATTR(type, S_IRUGO, serio_show_id_type, NULL);
443 static DEVICE_ATTR(proto, S_IRUGO, serio_show_id_proto, NULL);
444 static DEVICE_ATTR(id, S_IRUGO, serio_show_id_id, NULL);
445 static DEVICE_ATTR(extra, S_IRUGO, serio_show_id_extra, NULL);
447 static struct attribute *serio_device_id_attrs[] = {
449 &dev_attr_proto.attr,
451 &dev_attr_extra.attr,
455 static struct attribute_group serio_id_attr_group = {
457 .attrs = serio_device_id_attrs,
460 static ssize_t serio_rebind_driver(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
462 struct serio *serio = to_serio_port(dev);
463 struct device_driver *drv;
466 error = mutex_lock_interruptible(&serio_mutex);
470 if (!strncmp(buf, "none", count)) {
471 serio_disconnect_port(serio);
472 } else if (!strncmp(buf, "reconnect", count)) {
473 serio_reconnect_port(serio);
474 } else if (!strncmp(buf, "rescan", count)) {
475 serio_disconnect_port(serio);
476 serio_find_driver(serio);
477 } else if ((drv = driver_find(buf, &serio_bus)) != NULL) {
478 serio_disconnect_port(serio);
479 error = serio_bind_driver(serio, to_serio_driver(drv));
485 mutex_unlock(&serio_mutex);
487 return error ? error : count;
490 static ssize_t serio_show_bind_mode(struct device *dev, struct device_attribute *attr, char *buf)
492 struct serio *serio = to_serio_port(dev);
493 return sprintf(buf, "%s\n", serio->manual_bind ? "manual" : "auto");
496 static ssize_t serio_set_bind_mode(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
498 struct serio *serio = to_serio_port(dev);
502 if (!strncmp(buf, "manual", count)) {
503 serio->manual_bind = 1;
504 } else if (!strncmp(buf, "auto", count)) {
505 serio->manual_bind = 0;
513 static struct device_attribute serio_device_attrs[] = {
514 __ATTR(description, S_IRUGO, serio_show_description, NULL),
515 __ATTR(modalias, S_IRUGO, serio_show_modalias, NULL),
516 __ATTR(drvctl, S_IWUSR, NULL, serio_rebind_driver),
517 __ATTR(bind_mode, S_IWUSR | S_IRUGO, serio_show_bind_mode, serio_set_bind_mode),
522 static void serio_release_port(struct device *dev)
524 struct serio *serio = to_serio_port(dev);
527 module_put(THIS_MODULE);
531 * Prepare serio port for registration.
533 static void serio_init_port(struct serio *serio)
535 static atomic_t serio_no = ATOMIC_INIT(0);
537 __module_get(THIS_MODULE);
539 INIT_LIST_HEAD(&serio->node);
540 spin_lock_init(&serio->lock);
541 mutex_init(&serio->drv_mutex);
542 device_initialize(&serio->dev);
543 snprintf(serio->dev.bus_id, sizeof(serio->dev.bus_id),
544 "serio%ld", (long)atomic_inc_return(&serio_no) - 1);
545 serio->dev.bus = &serio_bus;
546 serio->dev.release = serio_release_port;
548 serio->dev.parent = &serio->parent->dev;
549 serio->depth = serio->parent->depth + 1;
552 lockdep_set_subclass(&serio->lock, serio->depth);
556 * Complete serio port registration.
557 * Driver core will attempt to find appropriate driver for the port.
559 static void serio_add_port(struct serio *serio)
564 serio_pause_rx(serio->parent);
565 serio->parent->child = serio;
566 serio_continue_rx(serio->parent);
569 list_add_tail(&serio->node, &serio_list);
572 error = device_add(&serio->dev);
575 "serio: device_add() failed for %s (%s), error: %d\n",
576 serio->phys, serio->name, error);
578 serio->registered = 1;
579 error = sysfs_create_group(&serio->dev.kobj, &serio_id_attr_group);
582 "serio: sysfs_create_group() failed for %s (%s), error: %d\n",
583 serio->phys, serio->name, error);
588 * serio_destroy_port() completes deregistration process and removes
589 * port from the system
591 static void serio_destroy_port(struct serio *serio)
595 child = serio_get_pending_child(serio);
597 serio_remove_pending_events(child);
598 put_device(&child->dev);
605 serio_pause_rx(serio->parent);
606 serio->parent->child = NULL;
607 serio_continue_rx(serio->parent);
608 serio->parent = NULL;
611 if (serio->registered) {
612 sysfs_remove_group(&serio->dev.kobj, &serio_id_attr_group);
613 device_del(&serio->dev);
614 serio->registered = 0;
617 list_del_init(&serio->node);
618 serio_remove_pending_events(serio);
619 put_device(&serio->dev);
623 * Reconnect serio port and all its children (re-initialize attached devices)
625 static void serio_reconnect_port(struct serio *serio)
628 if (serio_reconnect_driver(serio)) {
629 serio_disconnect_port(serio);
630 serio_find_driver(serio);
631 /* Ok, old children are now gone, we are done */
634 serio = serio->child;
639 * serio_disconnect_port() unbinds a port from its driver. As a side effect
640 * all child ports are unbound and destroyed.
642 static void serio_disconnect_port(struct serio *serio)
644 struct serio *s, *parent;
648 * Children ports should be disconnected and destroyed
649 * first, staring with the leaf one, since we don't want
652 for (s = serio; s->child; s = s->child)
658 device_release_driver(&s->dev);
659 serio_destroy_port(s);
660 } while ((s = parent) != serio);
664 * Ok, no children left, now disconnect this port
666 device_release_driver(&serio->dev);
669 void serio_rescan(struct serio *serio)
671 serio_queue_event(serio, NULL, SERIO_RESCAN_PORT);
674 void serio_reconnect(struct serio *serio)
676 serio_queue_event(serio, NULL, SERIO_RECONNECT_PORT);
680 * Submits register request to kseriod for subsequent execution.
681 * Note that port registration is always asynchronous.
683 void __serio_register_port(struct serio *serio, struct module *owner)
685 serio_init_port(serio);
686 serio_queue_event(serio, owner, SERIO_REGISTER_PORT);
690 * Synchronously unregisters serio port.
692 void serio_unregister_port(struct serio *serio)
694 mutex_lock(&serio_mutex);
695 serio_disconnect_port(serio);
696 serio_destroy_port(serio);
697 mutex_unlock(&serio_mutex);
701 * Safely unregisters child port if one is present.
703 void serio_unregister_child_port(struct serio *serio)
705 mutex_lock(&serio_mutex);
707 serio_disconnect_port(serio->child);
708 serio_destroy_port(serio->child);
710 mutex_unlock(&serio_mutex);
715 * Serio driver operations
718 static ssize_t serio_driver_show_description(struct device_driver *drv, char *buf)
720 struct serio_driver *driver = to_serio_driver(drv);
721 return sprintf(buf, "%s\n", driver->description ? driver->description : "(none)");
724 static ssize_t serio_driver_show_bind_mode(struct device_driver *drv, char *buf)
726 struct serio_driver *serio_drv = to_serio_driver(drv);
727 return sprintf(buf, "%s\n", serio_drv->manual_bind ? "manual" : "auto");
730 static ssize_t serio_driver_set_bind_mode(struct device_driver *drv, const char *buf, size_t count)
732 struct serio_driver *serio_drv = to_serio_driver(drv);
736 if (!strncmp(buf, "manual", count)) {
737 serio_drv->manual_bind = 1;
738 } else if (!strncmp(buf, "auto", count)) {
739 serio_drv->manual_bind = 0;
748 static struct driver_attribute serio_driver_attrs[] = {
749 __ATTR(description, S_IRUGO, serio_driver_show_description, NULL),
750 __ATTR(bind_mode, S_IWUSR | S_IRUGO,
751 serio_driver_show_bind_mode, serio_driver_set_bind_mode),
755 static int serio_driver_probe(struct device *dev)
757 struct serio *serio = to_serio_port(dev);
758 struct serio_driver *drv = to_serio_driver(dev->driver);
760 return serio_connect_driver(serio, drv);
763 static int serio_driver_remove(struct device *dev)
765 struct serio *serio = to_serio_port(dev);
767 serio_disconnect_driver(serio);
771 static void serio_cleanup(struct serio *serio)
773 mutex_lock(&serio->drv_mutex);
774 if (serio->drv && serio->drv->cleanup)
775 serio->drv->cleanup(serio);
776 mutex_unlock(&serio->drv_mutex);
779 static void serio_shutdown(struct device *dev)
781 struct serio *serio = to_serio_port(dev);
783 serio_cleanup(serio);
786 static void serio_attach_driver(struct serio_driver *drv)
790 error = driver_attach(&drv->driver);
793 "serio: driver_attach() failed for %s with error %d\n",
794 drv->driver.name, error);
797 int __serio_register_driver(struct serio_driver *drv, struct module *owner, const char *mod_name)
799 int manual_bind = drv->manual_bind;
802 drv->driver.bus = &serio_bus;
803 drv->driver.owner = owner;
804 drv->driver.mod_name = mod_name;
807 * Temporarily disable automatic binding because probing
808 * takes long time and we are better off doing it in kseriod
810 drv->manual_bind = 1;
812 error = driver_register(&drv->driver);
815 "serio: driver_register() failed for %s, error: %d\n",
816 drv->driver.name, error);
821 * Restore original bind mode and let kseriod bind the
822 * driver to free ports
825 drv->manual_bind = 0;
826 error = serio_queue_event(drv, NULL, SERIO_ATTACH_DRIVER);
828 driver_unregister(&drv->driver);
836 void serio_unregister_driver(struct serio_driver *drv)
840 mutex_lock(&serio_mutex);
842 drv->manual_bind = 1; /* so serio_find_driver ignores it */
843 serio_remove_pending_events(drv);
846 list_for_each_entry(serio, &serio_list, node) {
847 if (serio->drv == drv) {
848 serio_disconnect_port(serio);
849 serio_find_driver(serio);
850 /* we could've deleted some ports, restart */
855 driver_unregister(&drv->driver);
856 mutex_unlock(&serio_mutex);
859 static void serio_set_drv(struct serio *serio, struct serio_driver *drv)
861 serio_pause_rx(serio);
863 serio_continue_rx(serio);
866 static int serio_bus_match(struct device *dev, struct device_driver *drv)
868 struct serio *serio = to_serio_port(dev);
869 struct serio_driver *serio_drv = to_serio_driver(drv);
871 if (serio->manual_bind || serio_drv->manual_bind)
874 return serio_match_port(serio_drv->id_table, serio);
877 #ifdef CONFIG_HOTPLUG
879 #define SERIO_ADD_UEVENT_VAR(fmt, val...) \
881 int err = add_uevent_var(env, fmt, val); \
886 static int serio_uevent(struct device *dev, struct kobj_uevent_env *env)
893 serio = to_serio_port(dev);
895 SERIO_ADD_UEVENT_VAR("SERIO_TYPE=%02x", serio->id.type);
896 SERIO_ADD_UEVENT_VAR("SERIO_PROTO=%02x", serio->id.proto);
897 SERIO_ADD_UEVENT_VAR("SERIO_ID=%02x", serio->id.id);
898 SERIO_ADD_UEVENT_VAR("SERIO_EXTRA=%02x", serio->id.extra);
899 SERIO_ADD_UEVENT_VAR("MODALIAS=serio:ty%02Xpr%02Xid%02Xex%02X",
900 serio->id.type, serio->id.proto, serio->id.id, serio->id.extra);
904 #undef SERIO_ADD_UEVENT_VAR
908 static int serio_uevent(struct device *dev, struct kobj_uevent_env *env)
913 #endif /* CONFIG_HOTPLUG */
916 static int serio_suspend(struct device *dev, pm_message_t state)
918 if (dev->power.power_state.event != state.event) {
919 if (state.event == PM_EVENT_SUSPEND)
920 serio_cleanup(to_serio_port(dev));
922 dev->power.power_state = state;
928 static int serio_resume(struct device *dev)
930 struct serio *serio = to_serio_port(dev);
932 if (dev->power.power_state.event != PM_EVENT_ON &&
933 serio_reconnect_driver(serio)) {
935 * Driver re-probing can take a while, so better let kseriod
941 dev->power.power_state = PMSG_ON;
945 #endif /* CONFIG_PM */
947 /* called from serio_driver->connect/disconnect methods under serio_mutex */
948 int serio_open(struct serio *serio, struct serio_driver *drv)
950 serio_set_drv(serio, drv);
952 if (serio->open && serio->open(serio)) {
953 serio_set_drv(serio, NULL);
959 /* called from serio_driver->connect/disconnect methods under serio_mutex */
960 void serio_close(struct serio *serio)
965 serio_set_drv(serio, NULL);
968 irqreturn_t serio_interrupt(struct serio *serio,
969 unsigned char data, unsigned int dfl)
972 irqreturn_t ret = IRQ_NONE;
974 spin_lock_irqsave(&serio->lock, flags);
976 if (likely(serio->drv)) {
977 ret = serio->drv->interrupt(serio, data, dfl);
978 } else if (!dfl && serio->registered) {
983 spin_unlock_irqrestore(&serio->lock, flags);
988 static struct bus_type serio_bus = {
990 .dev_attrs = serio_device_attrs,
991 .drv_attrs = serio_driver_attrs,
992 .match = serio_bus_match,
993 .uevent = serio_uevent,
994 .probe = serio_driver_probe,
995 .remove = serio_driver_remove,
996 .shutdown = serio_shutdown,
998 .suspend = serio_suspend,
999 .resume = serio_resume,
1003 static int __init serio_init(void)
1007 error = bus_register(&serio_bus);
1009 printk(KERN_ERR "serio: failed to register serio bus, error: %d\n", error);
1013 serio_task = kthread_run(serio_thread, NULL, "kseriod");
1014 if (IS_ERR(serio_task)) {
1015 bus_unregister(&serio_bus);
1016 error = PTR_ERR(serio_task);
1017 printk(KERN_ERR "serio: Failed to start kseriod, error: %d\n", error);
1024 static void __exit serio_exit(void)
1026 bus_unregister(&serio_bus);
1027 kthread_stop(serio_task);
1030 subsys_initcall(serio_init);
1031 module_exit(serio_exit);