1/*
2 *  The Serio abstraction module
3 *
4 *  Copyright (c) 1999-2004 Vojtech Pavlik
5 *  Copyright (c) 2004 Dmitry Torokhov
6 *  Copyright (c) 2003 Daniele Bellucci
7 */
8
9/*
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.
14 *
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.
19 *
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
23 *
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
27 */
28
29#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
30
31#include <linux/stddef.h>
32#include <linux/module.h>
33#include <linux/serio.h>
34#include <linux/errno.h>
35#include <linux/sched.h>
36#include <linux/slab.h>
37#include <linux/workqueue.h>
38#include <linux/mutex.h>
39
40MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
41MODULE_DESCRIPTION("Serio abstraction core");
42MODULE_LICENSE("GPL");
43
44/*
45 * serio_mutex protects entire serio subsystem and is taken every time
46 * serio port or driver registered or unregistered.
47 */
48static DEFINE_MUTEX(serio_mutex);
49
50static LIST_HEAD(serio_list);
51
52static struct bus_type serio_bus;
53
54static void serio_add_port(struct serio *serio);
55static int serio_reconnect_port(struct serio *serio);
56static void serio_disconnect_port(struct serio *serio);
57static void serio_reconnect_subtree(struct serio *serio);
58static void serio_attach_driver(struct serio_driver *drv);
59
60static int serio_connect_driver(struct serio *serio, struct serio_driver *drv)
61{
62	int retval;
63
64	mutex_lock(&serio->drv_mutex);
65	retval = drv->connect(serio, drv);
66	mutex_unlock(&serio->drv_mutex);
67
68	return retval;
69}
70
71static int serio_reconnect_driver(struct serio *serio)
72{
73	int retval = -1;
74
75	mutex_lock(&serio->drv_mutex);
76	if (serio->drv && serio->drv->reconnect)
77		retval = serio->drv->reconnect(serio);
78	mutex_unlock(&serio->drv_mutex);
79
80	return retval;
81}
82
83static void serio_disconnect_driver(struct serio *serio)
84{
85	mutex_lock(&serio->drv_mutex);
86	if (serio->drv)
87		serio->drv->disconnect(serio);
88	mutex_unlock(&serio->drv_mutex);
89}
90
91static int serio_match_port(const struct serio_device_id *ids, struct serio *serio)
92{
93	while (ids->type || ids->proto) {
94		if ((ids->type == SERIO_ANY || ids->type == serio->id.type) &&
95		    (ids->proto == SERIO_ANY || ids->proto == serio->id.proto) &&
96		    (ids->extra == SERIO_ANY || ids->extra == serio->id.extra) &&
97		    (ids->id == SERIO_ANY || ids->id == serio->id.id))
98			return 1;
99		ids++;
100	}
101	return 0;
102}
103
104/*
105 * Basic serio -> driver core mappings
106 */
107
108static int serio_bind_driver(struct serio *serio, struct serio_driver *drv)
109{
110	int error;
111
112	if (serio_match_port(drv->id_table, serio)) {
113
114		serio->dev.driver = &drv->driver;
115		if (serio_connect_driver(serio, drv)) {
116			serio->dev.driver = NULL;
117			return -ENODEV;
118		}
119
120		error = device_bind_driver(&serio->dev);
121		if (error) {
122			dev_warn(&serio->dev,
123				 "device_bind_driver() failed for %s (%s) and %s, error: %d\n",
124				 serio->phys, serio->name,
125				 drv->description, error);
126			serio_disconnect_driver(serio);
127			serio->dev.driver = NULL;
128			return error;
129		}
130	}
131	return 0;
132}
133
134static void serio_find_driver(struct serio *serio)
135{
136	int error;
137
138	error = device_attach(&serio->dev);
139	if (error < 0)
140		dev_warn(&serio->dev,
141			 "device_attach() failed for %s (%s), error: %d\n",
142			 serio->phys, serio->name, error);
143}
144
145
146/*
147 * Serio event processing.
148 */
149
150enum serio_event_type {
151	SERIO_RESCAN_PORT,
152	SERIO_RECONNECT_PORT,
153	SERIO_RECONNECT_SUBTREE,
154	SERIO_REGISTER_PORT,
155	SERIO_ATTACH_DRIVER,
156};
157
158struct serio_event {
159	enum serio_event_type type;
160	void *object;
161	struct module *owner;
162	struct list_head node;
163};
164
165static DEFINE_SPINLOCK(serio_event_lock);	/* protects serio_event_list */
166static LIST_HEAD(serio_event_list);
167
168static struct serio_event *serio_get_event(void)
169{
170	struct serio_event *event = NULL;
171	unsigned long flags;
172
173	spin_lock_irqsave(&serio_event_lock, flags);
174
175	if (!list_empty(&serio_event_list)) {
176		event = list_first_entry(&serio_event_list,
177					 struct serio_event, node);
178		list_del_init(&event->node);
179	}
180
181	spin_unlock_irqrestore(&serio_event_lock, flags);
182	return event;
183}
184
185static void serio_free_event(struct serio_event *event)
186{
187	module_put(event->owner);
188	kfree(event);
189}
190
191static void serio_remove_duplicate_events(void *object,
192					  enum serio_event_type type)
193{
194	struct serio_event *e, *next;
195	unsigned long flags;
196
197	spin_lock_irqsave(&serio_event_lock, flags);
198
199	list_for_each_entry_safe(e, next, &serio_event_list, node) {
200		if (object == e->object) {
201			/*
202			 * If this event is of different type we should not
203			 * look further - we only suppress duplicate events
204			 * that were sent back-to-back.
205			 */
206			if (type != e->type)
207				break;
208
209			list_del_init(&e->node);
210			serio_free_event(e);
211		}
212	}
213
214	spin_unlock_irqrestore(&serio_event_lock, flags);
215}
216
217static void serio_handle_event(struct work_struct *work)
218{
219	struct serio_event *event;
220
221	mutex_lock(&serio_mutex);
222
223	while ((event = serio_get_event())) {
224
225		switch (event->type) {
226
227		case SERIO_REGISTER_PORT:
228			serio_add_port(event->object);
229			break;
230
231		case SERIO_RECONNECT_PORT:
232			serio_reconnect_port(event->object);
233			break;
234
235		case SERIO_RESCAN_PORT:
236			serio_disconnect_port(event->object);
237			serio_find_driver(event->object);
238			break;
239
240		case SERIO_RECONNECT_SUBTREE:
241			serio_reconnect_subtree(event->object);
242			break;
243
244		case SERIO_ATTACH_DRIVER:
245			serio_attach_driver(event->object);
246			break;
247		}
248
249		serio_remove_duplicate_events(event->object, event->type);
250		serio_free_event(event);
251	}
252
253	mutex_unlock(&serio_mutex);
254}
255
256static DECLARE_WORK(serio_event_work, serio_handle_event);
257
258static int serio_queue_event(void *object, struct module *owner,
259			     enum serio_event_type event_type)
260{
261	unsigned long flags;
262	struct serio_event *event;
263	int retval = 0;
264
265	spin_lock_irqsave(&serio_event_lock, flags);
266
267	/*
268	 * Scan event list for the other events for the same serio port,
269	 * starting with the most recent one. If event is the same we
270	 * do not need add new one. If event is of different type we
271	 * need to add this event and should not look further because
272	 * we need to preseve sequence of distinct events.
273	 */
274	list_for_each_entry_reverse(event, &serio_event_list, node) {
275		if (event->object == object) {
276			if (event->type == event_type)
277				goto out;
278			break;
279		}
280	}
281
282	event = kmalloc(sizeof(struct serio_event), GFP_ATOMIC);
283	if (!event) {
284		pr_err("Not enough memory to queue event %d\n", event_type);
285		retval = -ENOMEM;
286		goto out;
287	}
288
289	if (!try_module_get(owner)) {
290		pr_warning("Can't get module reference, dropping event %d\n",
291			   event_type);
292		kfree(event);
293		retval = -EINVAL;
294		goto out;
295	}
296
297	event->type = event_type;
298	event->object = object;
299	event->owner = owner;
300
301	list_add_tail(&event->node, &serio_event_list);
302	queue_work(system_long_wq, &serio_event_work);
303
304out:
305	spin_unlock_irqrestore(&serio_event_lock, flags);
306	return retval;
307}
308
309/*
310 * Remove all events that have been submitted for a given
311 * object, be it serio port or driver.
312 */
313static void serio_remove_pending_events(void *object)
314{
315	struct serio_event *event, *next;
316	unsigned long flags;
317
318	spin_lock_irqsave(&serio_event_lock, flags);
319
320	list_for_each_entry_safe(event, next, &serio_event_list, node) {
321		if (event->object == object) {
322			list_del_init(&event->node);
323			serio_free_event(event);
324		}
325	}
326
327	spin_unlock_irqrestore(&serio_event_lock, flags);
328}
329
330/*
331 * Locate child serio port (if any) that has not been fully registered yet.
332 *
333 * Children are registered by driver's connect() handler so there can't be a
334 * grandchild pending registration together with a child.
335 */
336static struct serio *serio_get_pending_child(struct serio *parent)
337{
338	struct serio_event *event;
339	struct serio *serio, *child = NULL;
340	unsigned long flags;
341
342	spin_lock_irqsave(&serio_event_lock, flags);
343
344	list_for_each_entry(event, &serio_event_list, node) {
345		if (event->type == SERIO_REGISTER_PORT) {
346			serio = event->object;
347			if (serio->parent == parent) {
348				child = serio;
349				break;
350			}
351		}
352	}
353
354	spin_unlock_irqrestore(&serio_event_lock, flags);
355	return child;
356}
357
358/*
359 * Serio port operations
360 */
361
362static ssize_t serio_show_description(struct device *dev, struct device_attribute *attr, char *buf)
363{
364	struct serio *serio = to_serio_port(dev);
365	return sprintf(buf, "%s\n", serio->name);
366}
367
368static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, char *buf)
369{
370	struct serio *serio = to_serio_port(dev);
371
372	return sprintf(buf, "serio:ty%02Xpr%02Xid%02Xex%02X\n",
373			serio->id.type, serio->id.proto, serio->id.id, serio->id.extra);
374}
375
376static ssize_t type_show(struct device *dev, struct device_attribute *attr, char *buf)
377{
378	struct serio *serio = to_serio_port(dev);
379	return sprintf(buf, "%02x\n", serio->id.type);
380}
381
382static ssize_t proto_show(struct device *dev, struct device_attribute *attr, char *buf)
383{
384	struct serio *serio = to_serio_port(dev);
385	return sprintf(buf, "%02x\n", serio->id.proto);
386}
387
388static ssize_t id_show(struct device *dev, struct device_attribute *attr, char *buf)
389{
390	struct serio *serio = to_serio_port(dev);
391	return sprintf(buf, "%02x\n", serio->id.id);
392}
393
394static ssize_t extra_show(struct device *dev, struct device_attribute *attr, char *buf)
395{
396	struct serio *serio = to_serio_port(dev);
397	return sprintf(buf, "%02x\n", serio->id.extra);
398}
399
400static ssize_t drvctl_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
401{
402	struct serio *serio = to_serio_port(dev);
403	struct device_driver *drv;
404	int error;
405
406	error = mutex_lock_interruptible(&serio_mutex);
407	if (error)
408		return error;
409
410	if (!strncmp(buf, "none", count)) {
411		serio_disconnect_port(serio);
412	} else if (!strncmp(buf, "reconnect", count)) {
413		serio_reconnect_subtree(serio);
414	} else if (!strncmp(buf, "rescan", count)) {
415		serio_disconnect_port(serio);
416		serio_find_driver(serio);
417		serio_remove_duplicate_events(serio, SERIO_RESCAN_PORT);
418	} else if ((drv = driver_find(buf, &serio_bus)) != NULL) {
419		serio_disconnect_port(serio);
420		error = serio_bind_driver(serio, to_serio_driver(drv));
421		serio_remove_duplicate_events(serio, SERIO_RESCAN_PORT);
422	} else {
423		error = -EINVAL;
424	}
425
426	mutex_unlock(&serio_mutex);
427
428	return error ? error : count;
429}
430
431static ssize_t serio_show_bind_mode(struct device *dev, struct device_attribute *attr, char *buf)
432{
433	struct serio *serio = to_serio_port(dev);
434	return sprintf(buf, "%s\n", serio->manual_bind ? "manual" : "auto");
435}
436
437static ssize_t serio_set_bind_mode(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
438{
439	struct serio *serio = to_serio_port(dev);
440	int retval;
441
442	retval = count;
443	if (!strncmp(buf, "manual", count)) {
444		serio->manual_bind = true;
445	} else if (!strncmp(buf, "auto", count)) {
446		serio->manual_bind = false;
447	} else {
448		retval = -EINVAL;
449	}
450
451	return retval;
452}
453
454static ssize_t firmware_id_show(struct device *dev, struct device_attribute *attr, char *buf)
455{
456	struct serio *serio = to_serio_port(dev);
457
458	return sprintf(buf, "%s\n", serio->firmware_id);
459}
460
461static DEVICE_ATTR_RO(type);
462static DEVICE_ATTR_RO(proto);
463static DEVICE_ATTR_RO(id);
464static DEVICE_ATTR_RO(extra);
465
466static struct attribute *serio_device_id_attrs[] = {
467	&dev_attr_type.attr,
468	&dev_attr_proto.attr,
469	&dev_attr_id.attr,
470	&dev_attr_extra.attr,
471	NULL
472};
473
474static struct attribute_group serio_id_attr_group = {
475	.name	= "id",
476	.attrs	= serio_device_id_attrs,
477};
478
479static DEVICE_ATTR_RO(modalias);
480static DEVICE_ATTR_WO(drvctl);
481static DEVICE_ATTR(description, S_IRUGO, serio_show_description, NULL);
482static DEVICE_ATTR(bind_mode, S_IWUSR | S_IRUGO, serio_show_bind_mode, serio_set_bind_mode);
483static DEVICE_ATTR_RO(firmware_id);
484
485static struct attribute *serio_device_attrs[] = {
486	&dev_attr_modalias.attr,
487	&dev_attr_description.attr,
488	&dev_attr_drvctl.attr,
489	&dev_attr_bind_mode.attr,
490	&dev_attr_firmware_id.attr,
491	NULL
492};
493
494static struct attribute_group serio_device_attr_group = {
495	.attrs	= serio_device_attrs,
496};
497
498static const struct attribute_group *serio_device_attr_groups[] = {
499	&serio_id_attr_group,
500	&serio_device_attr_group,
501	NULL
502};
503
504static void serio_release_port(struct device *dev)
505{
506	struct serio *serio = to_serio_port(dev);
507
508	kfree(serio);
509	module_put(THIS_MODULE);
510}
511
512/*
513 * Prepare serio port for registration.
514 */
515static void serio_init_port(struct serio *serio)
516{
517	static atomic_t serio_no = ATOMIC_INIT(-1);
518
519	__module_get(THIS_MODULE);
520
521	INIT_LIST_HEAD(&serio->node);
522	INIT_LIST_HEAD(&serio->child_node);
523	INIT_LIST_HEAD(&serio->children);
524	spin_lock_init(&serio->lock);
525	mutex_init(&serio->drv_mutex);
526	device_initialize(&serio->dev);
527	dev_set_name(&serio->dev, "serio%lu",
528		     (unsigned long)atomic_inc_return(&serio_no));
529	serio->dev.bus = &serio_bus;
530	serio->dev.release = serio_release_port;
531	serio->dev.groups = serio_device_attr_groups;
532	if (serio->parent) {
533		serio->dev.parent = &serio->parent->dev;
534		serio->depth = serio->parent->depth + 1;
535	} else
536		serio->depth = 0;
537	lockdep_set_subclass(&serio->lock, serio->depth);
538}
539
540/*
541 * Complete serio port registration.
542 * Driver core will attempt to find appropriate driver for the port.
543 */
544static void serio_add_port(struct serio *serio)
545{
546	struct serio *parent = serio->parent;
547	int error;
548
549	if (parent) {
550		serio_pause_rx(parent);
551		list_add_tail(&serio->child_node, &parent->children);
552		serio_continue_rx(parent);
553	}
554
555	list_add_tail(&serio->node, &serio_list);
556
557	if (serio->start)
558		serio->start(serio);
559
560	error = device_add(&serio->dev);
561	if (error)
562		dev_err(&serio->dev,
563			"device_add() failed for %s (%s), error: %d\n",
564			serio->phys, serio->name, error);
565}
566
567/*
568 * serio_destroy_port() completes unregistration process and removes
569 * port from the system
570 */
571static void serio_destroy_port(struct serio *serio)
572{
573	struct serio *child;
574
575	while ((child = serio_get_pending_child(serio)) != NULL) {
576		serio_remove_pending_events(child);
577		put_device(&child->dev);
578	}
579
580	if (serio->stop)
581		serio->stop(serio);
582
583	if (serio->parent) {
584		serio_pause_rx(serio->parent);
585		list_del_init(&serio->child_node);
586		serio_continue_rx(serio->parent);
587		serio->parent = NULL;
588	}
589
590	if (device_is_registered(&serio->dev))
591		device_del(&serio->dev);
592
593	list_del_init(&serio->node);
594	serio_remove_pending_events(serio);
595	put_device(&serio->dev);
596}
597
598/*
599 * Reconnect serio port (re-initialize attached device).
600 * If reconnect fails (old device is no longer attached or
601 * there was no device to begin with) we do full rescan in
602 * hope of finding a driver for the port.
603 */
604static int serio_reconnect_port(struct serio *serio)
605{
606	int error = serio_reconnect_driver(serio);
607
608	if (error) {
609		serio_disconnect_port(serio);
610		serio_find_driver(serio);
611	}
612
613	return error;
614}
615
616/*
617 * Reconnect serio port and all its children (re-initialize attached
618 * devices).
619 */
620static void serio_reconnect_subtree(struct serio *root)
621{
622	struct serio *s = root;
623	int error;
624
625	do {
626		error = serio_reconnect_port(s);
627		if (!error) {
628			/*
629			 * Reconnect was successful, move on to do the
630			 * first child.
631			 */
632			if (!list_empty(&s->children)) {
633				s = list_first_entry(&s->children,
634						     struct serio, child_node);
635				continue;
636			}
637		}
638
639		/*
640		 * Either it was a leaf node or reconnect failed and it
641		 * became a leaf node. Continue reconnecting starting with
642		 * the next sibling of the parent node.
643		 */
644		while (s != root) {
645			struct serio *parent = s->parent;
646
647			if (!list_is_last(&s->child_node, &parent->children)) {
648				s = list_entry(s->child_node.next,
649					       struct serio, child_node);
650				break;
651			}
652
653			s = parent;
654		}
655	} while (s != root);
656}
657
658/*
659 * serio_disconnect_port() unbinds a port from its driver. As a side effect
660 * all children ports are unbound and destroyed.
661 */
662static void serio_disconnect_port(struct serio *serio)
663{
664	struct serio *s = serio;
665
666	/*
667	 * Children ports should be disconnected and destroyed
668	 * first; we travel the tree in depth-first order.
669	 */
670	while (!list_empty(&serio->children)) {
671
672		/* Locate a leaf */
673		while (!list_empty(&s->children))
674			s = list_first_entry(&s->children,
675					     struct serio, child_node);
676
677		/*
678		 * Prune this leaf node unless it is the one we
679		 * started with.
680		 */
681		if (s != serio) {
682			struct serio *parent = s->parent;
683
684			device_release_driver(&s->dev);
685			serio_destroy_port(s);
686
687			s = parent;
688		}
689	}
690
691	/*
692	 * OK, no children left, now disconnect this port.
693	 */
694	device_release_driver(&serio->dev);
695}
696
697void serio_rescan(struct serio *serio)
698{
699	serio_queue_event(serio, NULL, SERIO_RESCAN_PORT);
700}
701EXPORT_SYMBOL(serio_rescan);
702
703void serio_reconnect(struct serio *serio)
704{
705	serio_queue_event(serio, NULL, SERIO_RECONNECT_SUBTREE);
706}
707EXPORT_SYMBOL(serio_reconnect);
708
709/*
710 * Submits register request to kseriod for subsequent execution.
711 * Note that port registration is always asynchronous.
712 */
713void __serio_register_port(struct serio *serio, struct module *owner)
714{
715	serio_init_port(serio);
716	serio_queue_event(serio, owner, SERIO_REGISTER_PORT);
717}
718EXPORT_SYMBOL(__serio_register_port);
719
720/*
721 * Synchronously unregisters serio port.
722 */
723void serio_unregister_port(struct serio *serio)
724{
725	mutex_lock(&serio_mutex);
726	serio_disconnect_port(serio);
727	serio_destroy_port(serio);
728	mutex_unlock(&serio_mutex);
729}
730EXPORT_SYMBOL(serio_unregister_port);
731
732/*
733 * Safely unregisters children ports if they are present.
734 */
735void serio_unregister_child_port(struct serio *serio)
736{
737	struct serio *s, *next;
738
739	mutex_lock(&serio_mutex);
740	list_for_each_entry_safe(s, next, &serio->children, child_node) {
741		serio_disconnect_port(s);
742		serio_destroy_port(s);
743	}
744	mutex_unlock(&serio_mutex);
745}
746EXPORT_SYMBOL(serio_unregister_child_port);
747
748
749/*
750 * Serio driver operations
751 */
752
753static ssize_t description_show(struct device_driver *drv, char *buf)
754{
755	struct serio_driver *driver = to_serio_driver(drv);
756	return sprintf(buf, "%s\n", driver->description ? driver->description : "(none)");
757}
758static DRIVER_ATTR_RO(description);
759
760static ssize_t bind_mode_show(struct device_driver *drv, char *buf)
761{
762	struct serio_driver *serio_drv = to_serio_driver(drv);
763	return sprintf(buf, "%s\n", serio_drv->manual_bind ? "manual" : "auto");
764}
765
766static ssize_t bind_mode_store(struct device_driver *drv, const char *buf, size_t count)
767{
768	struct serio_driver *serio_drv = to_serio_driver(drv);
769	int retval;
770
771	retval = count;
772	if (!strncmp(buf, "manual", count)) {
773		serio_drv->manual_bind = true;
774	} else if (!strncmp(buf, "auto", count)) {
775		serio_drv->manual_bind = false;
776	} else {
777		retval = -EINVAL;
778	}
779
780	return retval;
781}
782static DRIVER_ATTR_RW(bind_mode);
783
784static struct attribute *serio_driver_attrs[] = {
785	&driver_attr_description.attr,
786	&driver_attr_bind_mode.attr,
787	NULL,
788};
789ATTRIBUTE_GROUPS(serio_driver);
790
791static int serio_driver_probe(struct device *dev)
792{
793	struct serio *serio = to_serio_port(dev);
794	struct serio_driver *drv = to_serio_driver(dev->driver);
795
796	return serio_connect_driver(serio, drv);
797}
798
799static int serio_driver_remove(struct device *dev)
800{
801	struct serio *serio = to_serio_port(dev);
802
803	serio_disconnect_driver(serio);
804	return 0;
805}
806
807static void serio_cleanup(struct serio *serio)
808{
809	mutex_lock(&serio->drv_mutex);
810	if (serio->drv && serio->drv->cleanup)
811		serio->drv->cleanup(serio);
812	mutex_unlock(&serio->drv_mutex);
813}
814
815static void serio_shutdown(struct device *dev)
816{
817	struct serio *serio = to_serio_port(dev);
818
819	serio_cleanup(serio);
820}
821
822static void serio_attach_driver(struct serio_driver *drv)
823{
824	int error;
825
826	error = driver_attach(&drv->driver);
827	if (error)
828		pr_warning("driver_attach() failed for %s with error %d\n",
829			   drv->driver.name, error);
830}
831
832int __serio_register_driver(struct serio_driver *drv, struct module *owner, const char *mod_name)
833{
834	bool manual_bind = drv->manual_bind;
835	int error;
836
837	drv->driver.bus = &serio_bus;
838	drv->driver.owner = owner;
839	drv->driver.mod_name = mod_name;
840
841	/*
842	 * Temporarily disable automatic binding because probing
843	 * takes long time and we are better off doing it in kseriod
844	 */
845	drv->manual_bind = true;
846
847	error = driver_register(&drv->driver);
848	if (error) {
849		pr_err("driver_register() failed for %s, error: %d\n",
850			drv->driver.name, error);
851		return error;
852	}
853
854	/*
855	 * Restore original bind mode and let kseriod bind the
856	 * driver to free ports
857	 */
858	if (!manual_bind) {
859		drv->manual_bind = false;
860		error = serio_queue_event(drv, NULL, SERIO_ATTACH_DRIVER);
861		if (error) {
862			driver_unregister(&drv->driver);
863			return error;
864		}
865	}
866
867	return 0;
868}
869EXPORT_SYMBOL(__serio_register_driver);
870
871void serio_unregister_driver(struct serio_driver *drv)
872{
873	struct serio *serio;
874
875	mutex_lock(&serio_mutex);
876
877	drv->manual_bind = true;	/* so serio_find_driver ignores it */
878	serio_remove_pending_events(drv);
879
880start_over:
881	list_for_each_entry(serio, &serio_list, node) {
882		if (serio->drv == drv) {
883			serio_disconnect_port(serio);
884			serio_find_driver(serio);
885			/* we could've deleted some ports, restart */
886			goto start_over;
887		}
888	}
889
890	driver_unregister(&drv->driver);
891	mutex_unlock(&serio_mutex);
892}
893EXPORT_SYMBOL(serio_unregister_driver);
894
895static void serio_set_drv(struct serio *serio, struct serio_driver *drv)
896{
897	serio_pause_rx(serio);
898	serio->drv = drv;
899	serio_continue_rx(serio);
900}
901
902static int serio_bus_match(struct device *dev, struct device_driver *drv)
903{
904	struct serio *serio = to_serio_port(dev);
905	struct serio_driver *serio_drv = to_serio_driver(drv);
906
907	if (serio->manual_bind || serio_drv->manual_bind)
908		return 0;
909
910	return serio_match_port(serio_drv->id_table, serio);
911}
912
913#define SERIO_ADD_UEVENT_VAR(fmt, val...)				\
914	do {								\
915		int err = add_uevent_var(env, fmt, val);		\
916		if (err)						\
917			return err;					\
918	} while (0)
919
920static int serio_uevent(struct device *dev, struct kobj_uevent_env *env)
921{
922	struct serio *serio;
923
924	if (!dev)
925		return -ENODEV;
926
927	serio = to_serio_port(dev);
928
929	SERIO_ADD_UEVENT_VAR("SERIO_TYPE=%02x", serio->id.type);
930	SERIO_ADD_UEVENT_VAR("SERIO_PROTO=%02x", serio->id.proto);
931	SERIO_ADD_UEVENT_VAR("SERIO_ID=%02x", serio->id.id);
932	SERIO_ADD_UEVENT_VAR("SERIO_EXTRA=%02x", serio->id.extra);
933
934	SERIO_ADD_UEVENT_VAR("MODALIAS=serio:ty%02Xpr%02Xid%02Xex%02X",
935				serio->id.type, serio->id.proto, serio->id.id, serio->id.extra);
936
937	if (serio->firmware_id[0])
938		SERIO_ADD_UEVENT_VAR("SERIO_FIRMWARE_ID=%s",
939				     serio->firmware_id);
940
941	return 0;
942}
943#undef SERIO_ADD_UEVENT_VAR
944
945#ifdef CONFIG_PM
946static int serio_suspend(struct device *dev)
947{
948	struct serio *serio = to_serio_port(dev);
949
950	serio_cleanup(serio);
951
952	return 0;
953}
954
955static int serio_resume(struct device *dev)
956{
957	struct serio *serio = to_serio_port(dev);
958
959	/*
960	 * Driver reconnect can take a while, so better let kseriod
961	 * deal with it.
962	 */
963	serio_queue_event(serio, NULL, SERIO_RECONNECT_PORT);
964
965	return 0;
966}
967
968static const struct dev_pm_ops serio_pm_ops = {
969	.suspend	= serio_suspend,
970	.resume		= serio_resume,
971	.poweroff	= serio_suspend,
972	.restore	= serio_resume,
973};
974#endif /* CONFIG_PM */
975
976/* called from serio_driver->connect/disconnect methods under serio_mutex */
977int serio_open(struct serio *serio, struct serio_driver *drv)
978{
979	serio_set_drv(serio, drv);
980
981	if (serio->open && serio->open(serio)) {
982		serio_set_drv(serio, NULL);
983		return -1;
984	}
985	return 0;
986}
987EXPORT_SYMBOL(serio_open);
988
989/* called from serio_driver->connect/disconnect methods under serio_mutex */
990void serio_close(struct serio *serio)
991{
992	if (serio->close)
993		serio->close(serio);
994
995	serio_set_drv(serio, NULL);
996}
997EXPORT_SYMBOL(serio_close);
998
999irqreturn_t serio_interrupt(struct serio *serio,
1000		unsigned char data, unsigned int dfl)
1001{
1002	unsigned long flags;
1003	irqreturn_t ret = IRQ_NONE;
1004
1005	spin_lock_irqsave(&serio->lock, flags);
1006
1007        if (likely(serio->drv)) {
1008                ret = serio->drv->interrupt(serio, data, dfl);
1009	} else if (!dfl && device_is_registered(&serio->dev)) {
1010		serio_rescan(serio);
1011		ret = IRQ_HANDLED;
1012	}
1013
1014	spin_unlock_irqrestore(&serio->lock, flags);
1015
1016	return ret;
1017}
1018EXPORT_SYMBOL(serio_interrupt);
1019
1020static struct bus_type serio_bus = {
1021	.name		= "serio",
1022	.drv_groups	= serio_driver_groups,
1023	.match		= serio_bus_match,
1024	.uevent		= serio_uevent,
1025	.probe		= serio_driver_probe,
1026	.remove		= serio_driver_remove,
1027	.shutdown	= serio_shutdown,
1028#ifdef CONFIG_PM
1029	.pm		= &serio_pm_ops,
1030#endif
1031};
1032
1033static int __init serio_init(void)
1034{
1035	int error;
1036
1037	error = bus_register(&serio_bus);
1038	if (error) {
1039		pr_err("Failed to register serio bus, error: %d\n", error);
1040		return error;
1041	}
1042
1043	return 0;
1044}
1045
1046static void __exit serio_exit(void)
1047{
1048	bus_unregister(&serio_bus);
1049
1050	/*
1051	 * There should not be any outstanding events but work may
1052	 * still be scheduled so simply cancel it.
1053	 */
1054	cancel_work_sync(&serio_event_work);
1055}
1056
1057subsys_initcall(serio_init);
1058module_exit(serio_exit);
1059