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_port_delayed
);
46 EXPORT_SYMBOL(__serio_register_driver
);
47 EXPORT_SYMBOL(serio_unregister_driver
);
48 EXPORT_SYMBOL(serio_open
);
49 EXPORT_SYMBOL(serio_close
);
50 EXPORT_SYMBOL(serio_rescan
);
51 EXPORT_SYMBOL(serio_reconnect
);
54 * serio_sem protects entire serio subsystem and is taken every time
55 * serio port or driver registrered or unregistered.
57 static DECLARE_MUTEX(serio_sem
);
59 static LIST_HEAD(serio_list
);
61 static struct bus_type serio_bus
= {
65 static void serio_add_port(struct serio
*serio
);
66 static void serio_destroy_port(struct serio
*serio
);
67 static void serio_reconnect_port(struct serio
*serio
);
68 static void serio_disconnect_port(struct serio
*serio
);
70 static int serio_connect_driver(struct serio
*serio
, struct serio_driver
*drv
)
74 down(&serio
->drv_sem
);
75 retval
= drv
->connect(serio
, drv
);
81 static int serio_reconnect_driver(struct serio
*serio
)
85 down(&serio
->drv_sem
);
86 if (serio
->drv
&& serio
->drv
->reconnect
)
87 retval
= serio
->drv
->reconnect(serio
);
93 static void serio_disconnect_driver(struct serio
*serio
)
95 down(&serio
->drv_sem
);
97 serio
->drv
->disconnect(serio
);
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 void serio_bind_driver(struct serio
*serio
, struct serio_driver
*drv
)
120 down_write(&serio_bus
.subsys
.rwsem
);
122 if (serio_match_port(drv
->id_table
, serio
)) {
123 serio
->dev
.driver
= &drv
->driver
;
124 if (serio_connect_driver(serio
, drv
)) {
125 serio
->dev
.driver
= NULL
;
128 device_bind_driver(&serio
->dev
);
131 up_write(&serio_bus
.subsys
.rwsem
);
134 static void serio_release_driver(struct serio
*serio
)
136 down_write(&serio_bus
.subsys
.rwsem
);
137 device_release_driver(&serio
->dev
);
138 up_write(&serio_bus
.subsys
.rwsem
);
141 static void serio_find_driver(struct serio
*serio
)
143 down_write(&serio_bus
.subsys
.rwsem
);
144 device_attach(&serio
->dev
);
145 up_write(&serio_bus
.subsys
.rwsem
);
150 * Serio event processing.
153 enum serio_event_type
{
157 SERIO_UNREGISTER_PORT
,
158 SERIO_REGISTER_DRIVER
,
162 enum serio_event_type type
;
164 struct module
*owner
;
165 struct list_head node
;
168 static DEFINE_SPINLOCK(serio_event_lock
); /* protects serio_event_list */
169 static LIST_HEAD(serio_event_list
);
170 static DECLARE_WAIT_QUEUE_HEAD(serio_wait
);
171 static struct task_struct
*serio_task
;
173 static void serio_queue_event(void *object
, struct module
*owner
,
174 enum serio_event_type event_type
)
177 struct serio_event
*event
;
179 spin_lock_irqsave(&serio_event_lock
, flags
);
182 * Scan event list for the other events for the same serio port,
183 * starting with the most recent one. If event is the same we
184 * do not need add new one. If event is of different type we
185 * need to add this event and should not look further because
186 * we need to preseve sequence of distinct events.
188 list_for_each_entry_reverse(event
, &serio_event_list
, node
) {
189 if (event
->object
== object
) {
190 if (event
->type
== event_type
)
196 if ((event
= kmalloc(sizeof(struct serio_event
), GFP_ATOMIC
))) {
197 if (!try_module_get(owner
)) {
198 printk(KERN_WARNING
"serio: Can't get module reference, dropping event %d\n", event_type
);
202 event
->type
= event_type
;
203 event
->object
= object
;
204 event
->owner
= owner
;
206 list_add_tail(&event
->node
, &serio_event_list
);
207 wake_up(&serio_wait
);
209 printk(KERN_ERR
"serio: Not enough memory to queue event %d\n", event_type
);
212 spin_unlock_irqrestore(&serio_event_lock
, flags
);
215 static void serio_free_event(struct serio_event
*event
)
217 module_put(event
->owner
);
221 static void serio_remove_duplicate_events(struct serio_event
*event
)
223 struct list_head
*node
, *next
;
224 struct serio_event
*e
;
227 spin_lock_irqsave(&serio_event_lock
, flags
);
229 list_for_each_safe(node
, next
, &serio_event_list
) {
230 e
= list_entry(node
, struct serio_event
, node
);
231 if (event
->object
== e
->object
) {
233 * If this event is of different type we should not
234 * look further - we only suppress duplicate events
235 * that were sent back-to-back.
237 if (event
->type
!= e
->type
)
245 spin_unlock_irqrestore(&serio_event_lock
, flags
);
249 static struct serio_event
*serio_get_event(void)
251 struct serio_event
*event
;
252 struct list_head
*node
;
255 spin_lock_irqsave(&serio_event_lock
, flags
);
257 if (list_empty(&serio_event_list
)) {
258 spin_unlock_irqrestore(&serio_event_lock
, flags
);
262 node
= serio_event_list
.next
;
263 event
= list_entry(node
, struct serio_event
, node
);
266 spin_unlock_irqrestore(&serio_event_lock
, flags
);
271 static void serio_handle_events(void)
273 struct serio_event
*event
;
274 struct serio_driver
*serio_drv
;
278 while ((event
= serio_get_event())) {
280 switch (event
->type
) {
281 case SERIO_REGISTER_PORT
:
282 serio_add_port(event
->object
);
285 case SERIO_UNREGISTER_PORT
:
286 serio_disconnect_port(event
->object
);
287 serio_destroy_port(event
->object
);
290 case SERIO_RECONNECT
:
291 serio_reconnect_port(event
->object
);
295 serio_disconnect_port(event
->object
);
296 serio_find_driver(event
->object
);
299 case SERIO_REGISTER_DRIVER
:
300 serio_drv
= event
->object
;
301 driver_register(&serio_drv
->driver
);
308 serio_remove_duplicate_events(event
);
309 serio_free_event(event
);
316 * Remove all events that have been submitted for a given serio port.
318 static void serio_remove_pending_events(struct serio
*serio
)
320 struct list_head
*node
, *next
;
321 struct serio_event
*event
;
324 spin_lock_irqsave(&serio_event_lock
, flags
);
326 list_for_each_safe(node
, next
, &serio_event_list
) {
327 event
= list_entry(node
, struct serio_event
, node
);
328 if (event
->object
== serio
) {
330 serio_free_event(event
);
334 spin_unlock_irqrestore(&serio_event_lock
, flags
);
338 * Destroy child serio port (if any) that has not been fully registered yet.
340 * Note that we rely on the fact that port can have only one child and therefore
341 * only one child registration request can be pending. Additionally, children
342 * are registered by driver's connect() handler so there can't be a grandchild
343 * pending registration together with a child.
345 static struct serio
*serio_get_pending_child(struct serio
*parent
)
347 struct serio_event
*event
;
348 struct serio
*serio
, *child
= NULL
;
351 spin_lock_irqsave(&serio_event_lock
, flags
);
353 list_for_each_entry(event
, &serio_event_list
, node
) {
354 if (event
->type
== SERIO_REGISTER_PORT
) {
355 serio
= event
->object
;
356 if (serio
->parent
== parent
) {
363 spin_unlock_irqrestore(&serio_event_lock
, flags
);
367 static int serio_thread(void *nothing
)
370 serio_handle_events();
371 wait_event_interruptible(serio_wait
,
372 kthread_should_stop() || !list_empty(&serio_event_list
));
373 try_to_freeze(PF_FREEZE
);
374 } while (!kthread_should_stop());
376 printk(KERN_DEBUG
"serio: kseriod exiting\n");
382 * Serio port operations
385 static ssize_t
serio_show_description(struct device
*dev
, char *buf
)
387 struct serio
*serio
= to_serio_port(dev
);
388 return sprintf(buf
, "%s\n", serio
->name
);
391 static ssize_t
serio_show_id_type(struct device
*dev
, char *buf
)
393 struct serio
*serio
= to_serio_port(dev
);
394 return sprintf(buf
, "%02x\n", serio
->id
.type
);
397 static ssize_t
serio_show_id_proto(struct device
*dev
, char *buf
)
399 struct serio
*serio
= to_serio_port(dev
);
400 return sprintf(buf
, "%02x\n", serio
->id
.proto
);
403 static ssize_t
serio_show_id_id(struct device
*dev
, char *buf
)
405 struct serio
*serio
= to_serio_port(dev
);
406 return sprintf(buf
, "%02x\n", serio
->id
.id
);
409 static ssize_t
serio_show_id_extra(struct device
*dev
, char *buf
)
411 struct serio
*serio
= to_serio_port(dev
);
412 return sprintf(buf
, "%02x\n", serio
->id
.extra
);
415 static DEVICE_ATTR(type
, S_IRUGO
, serio_show_id_type
, NULL
);
416 static DEVICE_ATTR(proto
, S_IRUGO
, serio_show_id_proto
, NULL
);
417 static DEVICE_ATTR(id
, S_IRUGO
, serio_show_id_id
, NULL
);
418 static DEVICE_ATTR(extra
, S_IRUGO
, serio_show_id_extra
, NULL
);
420 static struct attribute
*serio_device_id_attrs
[] = {
422 &dev_attr_proto
.attr
,
424 &dev_attr_extra
.attr
,
428 static struct attribute_group serio_id_attr_group
= {
430 .attrs
= serio_device_id_attrs
,
433 static ssize_t
serio_rebind_driver(struct device
*dev
, const char *buf
, size_t count
)
435 struct serio
*serio
= to_serio_port(dev
);
436 struct device_driver
*drv
;
439 retval
= down_interruptible(&serio_sem
);
444 if (!strncmp(buf
, "none", count
)) {
445 serio_disconnect_port(serio
);
446 } else if (!strncmp(buf
, "reconnect", count
)) {
447 serio_reconnect_port(serio
);
448 } else if (!strncmp(buf
, "rescan", count
)) {
449 serio_disconnect_port(serio
);
450 serio_find_driver(serio
);
451 } else if ((drv
= driver_find(buf
, &serio_bus
)) != NULL
) {
452 serio_disconnect_port(serio
);
453 serio_bind_driver(serio
, to_serio_driver(drv
));
464 static ssize_t
serio_show_bind_mode(struct device
*dev
, char *buf
)
466 struct serio
*serio
= to_serio_port(dev
);
467 return sprintf(buf
, "%s\n", serio
->manual_bind
? "manual" : "auto");
470 static ssize_t
serio_set_bind_mode(struct device
*dev
, const char *buf
, size_t count
)
472 struct serio
*serio
= to_serio_port(dev
);
476 if (!strncmp(buf
, "manual", count
)) {
477 serio
->manual_bind
= 1;
478 } else if (!strncmp(buf
, "auto", count
)) {
479 serio
->manual_bind
= 0;
487 static struct device_attribute serio_device_attrs
[] = {
488 __ATTR(description
, S_IRUGO
, serio_show_description
, NULL
),
489 __ATTR(drvctl
, S_IWUSR
, NULL
, serio_rebind_driver
),
490 __ATTR(bind_mode
, S_IWUSR
| S_IRUGO
, serio_show_bind_mode
, serio_set_bind_mode
),
495 static void serio_release_port(struct device
*dev
)
497 struct serio
*serio
= to_serio_port(dev
);
500 module_put(THIS_MODULE
);
504 * Prepare serio port for registration.
506 static void serio_init_port(struct serio
*serio
)
508 static atomic_t serio_no
= ATOMIC_INIT(0);
510 __module_get(THIS_MODULE
);
512 spin_lock_init(&serio
->lock
);
513 init_MUTEX(&serio
->drv_sem
);
514 device_initialize(&serio
->dev
);
515 snprintf(serio
->dev
.bus_id
, sizeof(serio
->dev
.bus_id
),
516 "serio%ld", (long)atomic_inc_return(&serio_no
) - 1);
517 serio
->dev
.bus
= &serio_bus
;
518 serio
->dev
.release
= serio_release_port
;
520 serio
->dev
.parent
= &serio
->parent
->dev
;
524 * Complete serio port registration.
525 * Driver core will attempt to find appropriate driver for the port.
527 static void serio_add_port(struct serio
*serio
)
530 serio_pause_rx(serio
->parent
);
531 serio
->parent
->child
= serio
;
532 serio_continue_rx(serio
->parent
);
535 list_add_tail(&serio
->node
, &serio_list
);
538 device_add(&serio
->dev
);
539 sysfs_create_group(&serio
->dev
.kobj
, &serio_id_attr_group
);
540 serio
->registered
= 1;
544 * serio_destroy_port() completes deregistration process and removes
545 * port from the system
547 static void serio_destroy_port(struct serio
*serio
)
551 child
= serio_get_pending_child(serio
);
553 serio_remove_pending_events(child
);
554 put_device(&child
->dev
);
561 serio_pause_rx(serio
->parent
);
562 serio
->parent
->child
= NULL
;
563 serio_continue_rx(serio
->parent
);
564 serio
->parent
= NULL
;
567 if (serio
->registered
) {
568 sysfs_remove_group(&serio
->dev
.kobj
, &serio_id_attr_group
);
569 device_del(&serio
->dev
);
570 list_del_init(&serio
->node
);
571 serio
->registered
= 0;
574 serio_remove_pending_events(serio
);
575 put_device(&serio
->dev
);
579 * Reconnect serio port and all its children (re-initialize attached devices)
581 static void serio_reconnect_port(struct serio
*serio
)
584 if (serio_reconnect_driver(serio
)) {
585 serio_disconnect_port(serio
);
586 serio_find_driver(serio
);
587 /* Ok, old children are now gone, we are done */
590 serio
= serio
->child
;
595 * serio_disconnect_port() unbinds a port from its driver. As a side effect
596 * all child ports are unbound and destroyed.
598 static void serio_disconnect_port(struct serio
*serio
)
600 struct serio
*s
, *parent
;
604 * Children ports should be disconnected and destroyed
605 * first, staring with the leaf one, since we don't want
608 for (s
= serio
; s
->child
; s
= s
->child
)
614 serio_release_driver(s
);
615 serio_destroy_port(s
);
616 } while ((s
= parent
) != serio
);
620 * Ok, no children left, now disconnect this port
622 serio_release_driver(serio
);
625 void serio_rescan(struct serio
*serio
)
627 serio_queue_event(serio
, NULL
, SERIO_RESCAN
);
630 void serio_reconnect(struct serio
*serio
)
632 serio_queue_event(serio
, NULL
, SERIO_RECONNECT
);
636 * Submits register request to kseriod for subsequent execution.
637 * Note that port registration is always asynchronous.
639 void __serio_register_port(struct serio
*serio
, struct module
*owner
)
641 serio_init_port(serio
);
642 serio_queue_event(serio
, owner
, SERIO_REGISTER_PORT
);
646 * Synchronously unregisters serio port.
648 void serio_unregister_port(struct serio
*serio
)
651 serio_disconnect_port(serio
);
652 serio_destroy_port(serio
);
657 * Submits register request to kseriod for subsequent execution.
658 * Can be used when it is not obvious whether the serio_sem is
659 * taken or not and when delayed execution is feasible.
661 void __serio_unregister_port_delayed(struct serio
*serio
, struct module
*owner
)
663 serio_queue_event(serio
, owner
, SERIO_UNREGISTER_PORT
);
668 * Serio driver operations
671 static ssize_t
serio_driver_show_description(struct device_driver
*drv
, char *buf
)
673 struct serio_driver
*driver
= to_serio_driver(drv
);
674 return sprintf(buf
, "%s\n", driver
->description
? driver
->description
: "(none)");
677 static ssize_t
serio_driver_show_bind_mode(struct device_driver
*drv
, char *buf
)
679 struct serio_driver
*serio_drv
= to_serio_driver(drv
);
680 return sprintf(buf
, "%s\n", serio_drv
->manual_bind
? "manual" : "auto");
683 static ssize_t
serio_driver_set_bind_mode(struct device_driver
*drv
, const char *buf
, size_t count
)
685 struct serio_driver
*serio_drv
= to_serio_driver(drv
);
689 if (!strncmp(buf
, "manual", count
)) {
690 serio_drv
->manual_bind
= 1;
691 } else if (!strncmp(buf
, "auto", count
)) {
692 serio_drv
->manual_bind
= 0;
701 static struct driver_attribute serio_driver_attrs
[] = {
702 __ATTR(description
, S_IRUGO
, serio_driver_show_description
, NULL
),
703 __ATTR(bind_mode
, S_IWUSR
| S_IRUGO
,
704 serio_driver_show_bind_mode
, serio_driver_set_bind_mode
),
708 static int serio_driver_probe(struct device
*dev
)
710 struct serio
*serio
= to_serio_port(dev
);
711 struct serio_driver
*drv
= to_serio_driver(dev
->driver
);
713 return serio_connect_driver(serio
, drv
);
716 static int serio_driver_remove(struct device
*dev
)
718 struct serio
*serio
= to_serio_port(dev
);
720 serio_disconnect_driver(serio
);
724 void __serio_register_driver(struct serio_driver
*drv
, struct module
*owner
)
726 drv
->driver
.bus
= &serio_bus
;
727 drv
->driver
.probe
= serio_driver_probe
;
728 drv
->driver
.remove
= serio_driver_remove
;
730 serio_queue_event(drv
, owner
, SERIO_REGISTER_DRIVER
);
733 void serio_unregister_driver(struct serio_driver
*drv
)
738 drv
->manual_bind
= 1; /* so serio_find_driver ignores it */
741 list_for_each_entry(serio
, &serio_list
, node
) {
742 if (serio
->drv
== drv
) {
743 serio_disconnect_port(serio
);
744 serio_find_driver(serio
);
745 /* we could've deleted some ports, restart */
750 driver_unregister(&drv
->driver
);
754 static void serio_set_drv(struct serio
*serio
, struct serio_driver
*drv
)
756 serio_pause_rx(serio
);
758 serio_continue_rx(serio
);
761 static int serio_bus_match(struct device
*dev
, struct device_driver
*drv
)
763 struct serio
*serio
= to_serio_port(dev
);
764 struct serio_driver
*serio_drv
= to_serio_driver(drv
);
766 if (serio
->manual_bind
|| serio_drv
->manual_bind
)
769 return serio_match_port(serio_drv
->id_table
, serio
);
772 #ifdef CONFIG_HOTPLUG
774 #define PUT_ENVP(fmt, val) \
776 envp[i++] = buffer; \
777 length += snprintf(buffer, buffer_size - length, fmt, val); \
778 if (buffer_size - length <= 0 || i >= num_envp) \
783 static int serio_hotplug(struct device
*dev
, char **envp
, int num_envp
, char *buffer
, int buffer_size
)
792 serio
= to_serio_port(dev
);
794 PUT_ENVP("SERIO_TYPE=%02x", serio
->id
.type
);
795 PUT_ENVP("SERIO_PROTO=%02x", serio
->id
.proto
);
796 PUT_ENVP("SERIO_ID=%02x", serio
->id
.id
);
797 PUT_ENVP("SERIO_EXTRA=%02x", serio
->id
.extra
);
807 static int serio_hotplug(struct device
*dev
, char **envp
, int num_envp
, char *buffer
, int buffer_size
)
812 #endif /* CONFIG_HOTPLUG */
814 static int serio_resume(struct device
*dev
)
816 struct serio
*serio
= to_serio_port(dev
);
818 if (serio_reconnect_driver(serio
)) {
820 * Driver re-probing can take a while, so better let kseriod
829 /* called from serio_driver->connect/disconnect methods under serio_sem */
830 int serio_open(struct serio
*serio
, struct serio_driver
*drv
)
832 serio_set_drv(serio
, drv
);
834 if (serio
->open
&& serio
->open(serio
)) {
835 serio_set_drv(serio
, NULL
);
841 /* called from serio_driver->connect/disconnect methods under serio_sem */
842 void serio_close(struct serio
*serio
)
847 serio_set_drv(serio
, NULL
);
850 irqreturn_t
serio_interrupt(struct serio
*serio
,
851 unsigned char data
, unsigned int dfl
, struct pt_regs
*regs
)
854 irqreturn_t ret
= IRQ_NONE
;
856 spin_lock_irqsave(&serio
->lock
, flags
);
858 if (likely(serio
->drv
)) {
859 ret
= serio
->drv
->interrupt(serio
, data
, dfl
, regs
);
860 } else if (!dfl
&& serio
->registered
) {
865 spin_unlock_irqrestore(&serio
->lock
, flags
);
870 static int __init
serio_init(void)
872 serio_task
= kthread_run(serio_thread
, NULL
, "kseriod");
873 if (IS_ERR(serio_task
)) {
874 printk(KERN_ERR
"serio: Failed to start kseriod\n");
875 return PTR_ERR(serio_task
);
878 serio_bus
.dev_attrs
= serio_device_attrs
;
879 serio_bus
.drv_attrs
= serio_driver_attrs
;
880 serio_bus
.match
= serio_bus_match
;
881 serio_bus
.hotplug
= serio_hotplug
;
882 serio_bus
.resume
= serio_resume
;
883 bus_register(&serio_bus
);
888 static void __exit
serio_exit(void)
890 bus_unregister(&serio_bus
);
891 kthread_stop(serio_task
);
894 module_init(serio_init
);
895 module_exit(serio_exit
);