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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 serio_show_modalias(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 serio_show_id_type(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 serio_show_id_proto(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 serio_show_id_id(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 serio_show_id_extra(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 DEVICE_ATTR(type, S_IRUGO, serio_show_id_type, NULL);
401static DEVICE_ATTR(proto, S_IRUGO, serio_show_id_proto, NULL);
402static DEVICE_ATTR(id, S_IRUGO, serio_show_id_id, NULL);
403static DEVICE_ATTR(extra, S_IRUGO, serio_show_id_extra, NULL);
404
405static struct attribute *serio_device_id_attrs[] = {
406 &dev_attr_type.attr,
407 &dev_attr_proto.attr,
408 &dev_attr_id.attr,
409 &dev_attr_extra.attr,
410 NULL
411};
412
413static struct attribute_group serio_id_attr_group = {
414 .name = "id",
415 .attrs = serio_device_id_attrs,
416};
417
418static const struct attribute_group *serio_device_attr_groups[] = {
419 &serio_id_attr_group,
420 NULL
421};
422
423static ssize_t serio_rebind_driver(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
424{
425 struct serio *serio = to_serio_port(dev);
426 struct device_driver *drv;
427 int error;
428
429 error = mutex_lock_interruptible(&serio_mutex);
430 if (error)
431 return error;
432
433 if (!strncmp(buf, "none", count)) {
434 serio_disconnect_port(serio);
435 } else if (!strncmp(buf, "reconnect", count)) {
436 serio_reconnect_subtree(serio);
437 } else if (!strncmp(buf, "rescan", count)) {
438 serio_disconnect_port(serio);
439 serio_find_driver(serio);
440 serio_remove_duplicate_events(serio, SERIO_RESCAN_PORT);
441 } else if ((drv = driver_find(buf, &serio_bus)) != NULL) {
442 serio_disconnect_port(serio);
443 error = serio_bind_driver(serio, to_serio_driver(drv));
444 put_driver(drv);
445 serio_remove_duplicate_events(serio, SERIO_RESCAN_PORT);
446 } else {
447 error = -EINVAL;
448 }
449
450 mutex_unlock(&serio_mutex);
451
452 return error ? error : count;
453}
454
455static ssize_t serio_show_bind_mode(struct device *dev, struct device_attribute *attr, char *buf)
456{
457 struct serio *serio = to_serio_port(dev);
458 return sprintf(buf, "%s\n", serio->manual_bind ? "manual" : "auto");
459}
460
461static ssize_t serio_set_bind_mode(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
462{
463 struct serio *serio = to_serio_port(dev);
464 int retval;
465
466 retval = count;
467 if (!strncmp(buf, "manual", count)) {
468 serio->manual_bind = true;
469 } else if (!strncmp(buf, "auto", count)) {
470 serio->manual_bind = false;
471 } else {
472 retval = -EINVAL;
473 }
474
475 return retval;
476}
477
478static struct device_attribute serio_device_attrs[] = {
479 __ATTR(description, S_IRUGO, serio_show_description, NULL),
480 __ATTR(modalias, S_IRUGO, serio_show_modalias, NULL),
481 __ATTR(drvctl, S_IWUSR, NULL, serio_rebind_driver),
482 __ATTR(bind_mode, S_IWUSR | S_IRUGO, serio_show_bind_mode, serio_set_bind_mode),
483 __ATTR_NULL
484};
485
486
487static void serio_release_port(struct device *dev)
488{
489 struct serio *serio = to_serio_port(dev);
490
491 kfree(serio);
492 module_put(THIS_MODULE);
493}
494
495/*
496 * Prepare serio port for registration.
497 */
498static void serio_init_port(struct serio *serio)
499{
500 static atomic_t serio_no = ATOMIC_INIT(0);
501
502 __module_get(THIS_MODULE);
503
504 INIT_LIST_HEAD(&serio->node);
505 INIT_LIST_HEAD(&serio->child_node);
506 INIT_LIST_HEAD(&serio->children);
507 spin_lock_init(&serio->lock);
508 mutex_init(&serio->drv_mutex);
509 device_initialize(&serio->dev);
510 dev_set_name(&serio->dev, "serio%ld",
511 (long)atomic_inc_return(&serio_no) - 1);
512 serio->dev.bus = &serio_bus;
513 serio->dev.release = serio_release_port;
514 serio->dev.groups = serio_device_attr_groups;
515 if (serio->parent) {
516 serio->dev.parent = &serio->parent->dev;
517 serio->depth = serio->parent->depth + 1;
518 } else
519 serio->depth = 0;
520 lockdep_set_subclass(&serio->lock, serio->depth);
521}
522
523/*
524 * Complete serio port registration.
525 * Driver core will attempt to find appropriate driver for the port.
526 */
527static void serio_add_port(struct serio *serio)
528{
529 struct serio *parent = serio->parent;
530 int error;
531
532 if (parent) {
533 serio_pause_rx(parent);
534 list_add_tail(&serio->child_node, &parent->children);
535 serio_continue_rx(parent);
536 }
537
538 list_add_tail(&serio->node, &serio_list);
539
540 if (serio->start)
541 serio->start(serio);
542
543 error = device_add(&serio->dev);
544 if (error)
545 dev_err(&serio->dev,
546 "device_add() failed for %s (%s), error: %d\n",
547 serio->phys, serio->name, error);
548}
549
550/*
551 * serio_destroy_port() completes unregistration process and removes
552 * port from the system
553 */
554static void serio_destroy_port(struct serio *serio)
555{
556 struct serio *child;
557
558 while ((child = serio_get_pending_child(serio)) != NULL) {
559 serio_remove_pending_events(child);
560 put_device(&child->dev);
561 }
562
563 if (serio->stop)
564 serio->stop(serio);
565
566 if (serio->parent) {
567 serio_pause_rx(serio->parent);
568 list_del_init(&serio->child_node);
569 serio_continue_rx(serio->parent);
570 serio->parent = NULL;
571 }
572
573 if (device_is_registered(&serio->dev))
574 device_del(&serio->dev);
575
576 list_del_init(&serio->node);
577 serio_remove_pending_events(serio);
578 put_device(&serio->dev);
579}
580
581/*
582 * Reconnect serio port (re-initialize attached device).
583 * If reconnect fails (old device is no longer attached or
584 * there was no device to begin with) we do full rescan in
585 * hope of finding a driver for the port.
586 */
587static int serio_reconnect_port(struct serio *serio)
588{
589 int error = serio_reconnect_driver(serio);
590
591 if (error) {
592 serio_disconnect_port(serio);
593 serio_find_driver(serio);
594 }
595
596 return error;
597}
598
599/*
600 * Reconnect serio port and all its children (re-initialize attached
601 * devices).
602 */
603static void serio_reconnect_subtree(struct serio *root)
604{
605 struct serio *s = root;
606 int error;
607
608 do {
609 error = serio_reconnect_port(s);
610 if (!error) {
611 /*
612 * Reconnect was successful, move on to do the
613 * first child.
614 */
615 if (!list_empty(&s->children)) {
616 s = list_first_entry(&s->children,
617 struct serio, child_node);
618 continue;
619 }
620 }
621
622 /*
623 * Either it was a leaf node or reconnect failed and it
624 * became a leaf node. Continue reconnecting starting with
625 * the next sibling of the parent node.
626 */
627 while (s != root) {
628 struct serio *parent = s->parent;
629
630 if (!list_is_last(&s->child_node, &parent->children)) {
631 s = list_entry(s->child_node.next,
632 struct serio, child_node);
633 break;
634 }
635
636 s = parent;
637 }
638 } while (s != root);
639}
640
641/*
642 * serio_disconnect_port() unbinds a port from its driver. As a side effect
643 * all children ports are unbound and destroyed.
644 */
645static void serio_disconnect_port(struct serio *serio)
646{
647 struct serio *s = serio;
648
649 /*
650 * Children ports should be disconnected and destroyed
651 * first; we travel the tree in depth-first order.
652 */
653 while (!list_empty(&serio->children)) {
654
655 /* Locate a leaf */
656 while (!list_empty(&s->children))
657 s = list_first_entry(&s->children,
658 struct serio, child_node);
659
660 /*
661 * Prune this leaf node unless it is the one we
662 * started with.
663 */
664 if (s != serio) {
665 struct serio *parent = s->parent;
666
667 device_release_driver(&s->dev);
668 serio_destroy_port(s);
669
670 s = parent;
671 }
672 }
673
674 /*
675 * OK, no children left, now disconnect this port.
676 */
677 device_release_driver(&serio->dev);
678}
679
680void serio_rescan(struct serio *serio)
681{
682 serio_queue_event(serio, NULL, SERIO_RESCAN_PORT);
683}
684EXPORT_SYMBOL(serio_rescan);
685
686void serio_reconnect(struct serio *serio)
687{
688 serio_queue_event(serio, NULL, SERIO_RECONNECT_SUBTREE);
689}
690EXPORT_SYMBOL(serio_reconnect);
691
692/*
693 * Submits register request to kseriod for subsequent execution.
694 * Note that port registration is always asynchronous.
695 */
696void __serio_register_port(struct serio *serio, struct module *owner)
697{
698 serio_init_port(serio);
699 serio_queue_event(serio, owner, SERIO_REGISTER_PORT);
700}
701EXPORT_SYMBOL(__serio_register_port);
702
703/*
704 * Synchronously unregisters serio port.
705 */
706void serio_unregister_port(struct serio *serio)
707{
708 mutex_lock(&serio_mutex);
709 serio_disconnect_port(serio);
710 serio_destroy_port(serio);
711 mutex_unlock(&serio_mutex);
712}
713EXPORT_SYMBOL(serio_unregister_port);
714
715/*
716 * Safely unregisters children ports if they are present.
717 */
718void serio_unregister_child_port(struct serio *serio)
719{
720 struct serio *s, *next;
721
722 mutex_lock(&serio_mutex);
723 list_for_each_entry_safe(s, next, &serio->children, child_node) {
724 serio_disconnect_port(s);
725 serio_destroy_port(s);
726 }
727 mutex_unlock(&serio_mutex);
728}
729EXPORT_SYMBOL(serio_unregister_child_port);
730
731
732/*
733 * Serio driver operations
734 */
735
736static ssize_t serio_driver_show_description(struct device_driver *drv, char *buf)
737{
738 struct serio_driver *driver = to_serio_driver(drv);
739 return sprintf(buf, "%s\n", driver->description ? driver->description : "(none)");
740}
741
742static ssize_t serio_driver_show_bind_mode(struct device_driver *drv, char *buf)
743{
744 struct serio_driver *serio_drv = to_serio_driver(drv);
745 return sprintf(buf, "%s\n", serio_drv->manual_bind ? "manual" : "auto");
746}
747
748static ssize_t serio_driver_set_bind_mode(struct device_driver *drv, const char *buf, size_t count)
749{
750 struct serio_driver *serio_drv = to_serio_driver(drv);
751 int retval;
752
753 retval = count;
754 if (!strncmp(buf, "manual", count)) {
755 serio_drv->manual_bind = true;
756 } else if (!strncmp(buf, "auto", count)) {
757 serio_drv->manual_bind = false;
758 } else {
759 retval = -EINVAL;
760 }
761
762 return retval;
763}
764
765
766static struct driver_attribute serio_driver_attrs[] = {
767 __ATTR(description, S_IRUGO, serio_driver_show_description, NULL),
768 __ATTR(bind_mode, S_IWUSR | S_IRUGO,
769 serio_driver_show_bind_mode, serio_driver_set_bind_mode),
770 __ATTR_NULL
771};
772
773static int serio_driver_probe(struct device *dev)
774{
775 struct serio *serio = to_serio_port(dev);
776 struct serio_driver *drv = to_serio_driver(dev->driver);
777
778 return serio_connect_driver(serio, drv);
779}
780
781static int serio_driver_remove(struct device *dev)
782{
783 struct serio *serio = to_serio_port(dev);
784
785 serio_disconnect_driver(serio);
786 return 0;
787}
788
789static void serio_cleanup(struct serio *serio)
790{
791 mutex_lock(&serio->drv_mutex);
792 if (serio->drv && serio->drv->cleanup)
793 serio->drv->cleanup(serio);
794 mutex_unlock(&serio->drv_mutex);
795}
796
797static void serio_shutdown(struct device *dev)
798{
799 struct serio *serio = to_serio_port(dev);
800
801 serio_cleanup(serio);
802}
803
804static void serio_attach_driver(struct serio_driver *drv)
805{
806 int error;
807
808 error = driver_attach(&drv->driver);
809 if (error)
810 pr_warning("driver_attach() failed for %s with error %d\n",
811 drv->driver.name, error);
812}
813
814int __serio_register_driver(struct serio_driver *drv, struct module *owner, const char *mod_name)
815{
816 bool manual_bind = drv->manual_bind;
817 int error;
818
819 drv->driver.bus = &serio_bus;
820 drv->driver.owner = owner;
821 drv->driver.mod_name = mod_name;
822
823 /*
824 * Temporarily disable automatic binding because probing
825 * takes long time and we are better off doing it in kseriod
826 */
827 drv->manual_bind = true;
828
829 error = driver_register(&drv->driver);
830 if (error) {
831 pr_err("driver_register() failed for %s, error: %d\n",
832 drv->driver.name, error);
833 return error;
834 }
835
836 /*
837 * Restore original bind mode and let kseriod bind the
838 * driver to free ports
839 */
840 if (!manual_bind) {
841 drv->manual_bind = false;
842 error = serio_queue_event(drv, NULL, SERIO_ATTACH_DRIVER);
843 if (error) {
844 driver_unregister(&drv->driver);
845 return error;
846 }
847 }
848
849 return 0;
850}
851EXPORT_SYMBOL(__serio_register_driver);
852
853void serio_unregister_driver(struct serio_driver *drv)
854{
855 struct serio *serio;
856
857 mutex_lock(&serio_mutex);
858
859 drv->manual_bind = true; /* so serio_find_driver ignores it */
860 serio_remove_pending_events(drv);
861
862start_over:
863 list_for_each_entry(serio, &serio_list, node) {
864 if (serio->drv == drv) {
865 serio_disconnect_port(serio);
866 serio_find_driver(serio);
867 /* we could've deleted some ports, restart */
868 goto start_over;
869 }
870 }
871
872 driver_unregister(&drv->driver);
873 mutex_unlock(&serio_mutex);
874}
875EXPORT_SYMBOL(serio_unregister_driver);
876
877static void serio_set_drv(struct serio *serio, struct serio_driver *drv)
878{
879 serio_pause_rx(serio);
880 serio->drv = drv;
881 serio_continue_rx(serio);
882}
883
884static int serio_bus_match(struct device *dev, struct device_driver *drv)
885{
886 struct serio *serio = to_serio_port(dev);
887 struct serio_driver *serio_drv = to_serio_driver(drv);
888
889 if (serio->manual_bind || serio_drv->manual_bind)
890 return 0;
891
892 return serio_match_port(serio_drv->id_table, serio);
893}
894
895#ifdef CONFIG_HOTPLUG
896
897#define SERIO_ADD_UEVENT_VAR(fmt, val...) \
898 do { \
899 int err = add_uevent_var(env, fmt, val); \
900 if (err) \
901 return err; \
902 } while (0)
903
904static int serio_uevent(struct device *dev, struct kobj_uevent_env *env)
905{
906 struct serio *serio;
907
908 if (!dev)
909 return -ENODEV;
910
911 serio = to_serio_port(dev);
912
913 SERIO_ADD_UEVENT_VAR("SERIO_TYPE=%02x", serio->id.type);
914 SERIO_ADD_UEVENT_VAR("SERIO_PROTO=%02x", serio->id.proto);
915 SERIO_ADD_UEVENT_VAR("SERIO_ID=%02x", serio->id.id);
916 SERIO_ADD_UEVENT_VAR("SERIO_EXTRA=%02x", serio->id.extra);
917 SERIO_ADD_UEVENT_VAR("MODALIAS=serio:ty%02Xpr%02Xid%02Xex%02X",
918 serio->id.type, serio->id.proto, serio->id.id, serio->id.extra);
919
920 return 0;
921}
922#undef SERIO_ADD_UEVENT_VAR
923
924#else
925
926static int serio_uevent(struct device *dev, struct kobj_uevent_env *env)
927{
928 return -ENODEV;
929}
930
931#endif /* CONFIG_HOTPLUG */
932
933#ifdef CONFIG_PM
934static int serio_suspend(struct device *dev)
935{
936 struct serio *serio = to_serio_port(dev);
937
938 serio_cleanup(serio);
939
940 return 0;
941}
942
943static int serio_resume(struct device *dev)
944{
945 struct serio *serio = to_serio_port(dev);
946
947 /*
948 * Driver reconnect can take a while, so better let kseriod
949 * deal with it.
950 */
951 serio_queue_event(serio, NULL, SERIO_RECONNECT_PORT);
952
953 return 0;
954}
955
956static const struct dev_pm_ops serio_pm_ops = {
957 .suspend = serio_suspend,
958 .resume = serio_resume,
959 .poweroff = serio_suspend,
960 .restore = serio_resume,
961};
962#endif /* CONFIG_PM */
963
964/* called from serio_driver->connect/disconnect methods under serio_mutex */
965int serio_open(struct serio *serio, struct serio_driver *drv)
966{
967 serio_set_drv(serio, drv);
968
969 if (serio->open && serio->open(serio)) {
970 serio_set_drv(serio, NULL);
971 return -1;
972 }
973 return 0;
974}
975EXPORT_SYMBOL(serio_open);
976
977/* called from serio_driver->connect/disconnect methods under serio_mutex */
978void serio_close(struct serio *serio)
979{
980 if (serio->close)
981 serio->close(serio);
982
983 serio_set_drv(serio, NULL);
984}
985EXPORT_SYMBOL(serio_close);
986
987irqreturn_t serio_interrupt(struct serio *serio,
988 unsigned char data, unsigned int dfl)
989{
990 unsigned long flags;
991 irqreturn_t ret = IRQ_NONE;
992
993 spin_lock_irqsave(&serio->lock, flags);
994
995 if (likely(serio->drv)) {
996 ret = serio->drv->interrupt(serio, data, dfl);
997 } else if (!dfl && device_is_registered(&serio->dev)) {
998 serio_rescan(serio);
999 ret = IRQ_HANDLED;
1000 }
1001
1002 spin_unlock_irqrestore(&serio->lock, flags);
1003
1004 return ret;
1005}
1006EXPORT_SYMBOL(serio_interrupt);
1007
1008static struct bus_type serio_bus = {
1009 .name = "serio",
1010 .dev_attrs = serio_device_attrs,
1011 .drv_attrs = serio_driver_attrs,
1012 .match = serio_bus_match,
1013 .uevent = serio_uevent,
1014 .probe = serio_driver_probe,
1015 .remove = serio_driver_remove,
1016 .shutdown = serio_shutdown,
1017#ifdef CONFIG_PM
1018 .pm = &serio_pm_ops,
1019#endif
1020};
1021
1022static int __init serio_init(void)
1023{
1024 int error;
1025
1026 error = bus_register(&serio_bus);
1027 if (error) {
1028 pr_err("Failed to register serio bus, error: %d\n", error);
1029 return error;
1030 }
1031
1032 return 0;
1033}
1034
1035static void __exit serio_exit(void)
1036{
1037 bus_unregister(&serio_bus);
1038
1039 /*
1040 * There should not be any outstanding events but work may
1041 * still be scheduled so simply cancel it.
1042 */
1043 cancel_work_sync(&serio_event_work);
1044}
1045
1046subsys_initcall(serio_init);
1047module_exit(serio_exit);
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * The Serio abstraction module
4 *
5 * Copyright (c) 1999-2004 Vojtech Pavlik
6 * Copyright (c) 2004 Dmitry Torokhov
7 * Copyright (c) 2003 Daniele Bellucci
8 */
9
10#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11
12#include <linux/stddef.h>
13#include <linux/module.h>
14#include <linux/serio.h>
15#include <linux/errno.h>
16#include <linux/sched.h>
17#include <linux/slab.h>
18#include <linux/workqueue.h>
19#include <linux/mutex.h>
20
21MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
22MODULE_DESCRIPTION("Serio abstraction core");
23MODULE_LICENSE("GPL");
24
25/*
26 * serio_mutex protects entire serio subsystem and is taken every time
27 * serio port or driver registered or unregistered.
28 */
29static DEFINE_MUTEX(serio_mutex);
30
31static LIST_HEAD(serio_list);
32
33static void serio_add_port(struct serio *serio);
34static int serio_reconnect_port(struct serio *serio);
35static void serio_disconnect_port(struct serio *serio);
36static void serio_reconnect_subtree(struct serio *serio);
37static void serio_attach_driver(struct serio_driver *drv);
38
39static int serio_connect_driver(struct serio *serio, struct serio_driver *drv)
40{
41 int retval;
42
43 mutex_lock(&serio->drv_mutex);
44 retval = drv->connect(serio, drv);
45 mutex_unlock(&serio->drv_mutex);
46
47 return retval;
48}
49
50static int serio_reconnect_driver(struct serio *serio)
51{
52 int retval = -1;
53
54 mutex_lock(&serio->drv_mutex);
55 if (serio->drv && serio->drv->reconnect)
56 retval = serio->drv->reconnect(serio);
57 mutex_unlock(&serio->drv_mutex);
58
59 return retval;
60}
61
62static void serio_disconnect_driver(struct serio *serio)
63{
64 mutex_lock(&serio->drv_mutex);
65 if (serio->drv)
66 serio->drv->disconnect(serio);
67 mutex_unlock(&serio->drv_mutex);
68}
69
70static int serio_match_port(const struct serio_device_id *ids, struct serio *serio)
71{
72 while (ids->type || ids->proto) {
73 if ((ids->type == SERIO_ANY || ids->type == serio->id.type) &&
74 (ids->proto == SERIO_ANY || ids->proto == serio->id.proto) &&
75 (ids->extra == SERIO_ANY || ids->extra == serio->id.extra) &&
76 (ids->id == SERIO_ANY || ids->id == serio->id.id))
77 return 1;
78 ids++;
79 }
80 return 0;
81}
82
83/*
84 * Basic serio -> driver core mappings
85 */
86
87static int serio_bind_driver(struct serio *serio, struct serio_driver *drv)
88{
89 int error;
90
91 if (serio_match_port(drv->id_table, serio)) {
92
93 serio->dev.driver = &drv->driver;
94 if (serio_connect_driver(serio, drv)) {
95 serio->dev.driver = NULL;
96 return -ENODEV;
97 }
98
99 error = device_bind_driver(&serio->dev);
100 if (error) {
101 dev_warn(&serio->dev,
102 "device_bind_driver() failed for %s (%s) and %s, error: %d\n",
103 serio->phys, serio->name,
104 drv->description, error);
105 serio_disconnect_driver(serio);
106 serio->dev.driver = NULL;
107 return error;
108 }
109 }
110 return 0;
111}
112
113static void serio_find_driver(struct serio *serio)
114{
115 int error;
116
117 error = device_attach(&serio->dev);
118 if (error < 0 && error != -EPROBE_DEFER)
119 dev_warn(&serio->dev,
120 "device_attach() failed for %s (%s), error: %d\n",
121 serio->phys, serio->name, error);
122}
123
124
125/*
126 * Serio event processing.
127 */
128
129enum serio_event_type {
130 SERIO_RESCAN_PORT,
131 SERIO_RECONNECT_PORT,
132 SERIO_RECONNECT_SUBTREE,
133 SERIO_REGISTER_PORT,
134 SERIO_ATTACH_DRIVER,
135};
136
137struct serio_event {
138 enum serio_event_type type;
139 void *object;
140 struct module *owner;
141 struct list_head node;
142};
143
144static DEFINE_SPINLOCK(serio_event_lock); /* protects serio_event_list */
145static LIST_HEAD(serio_event_list);
146
147static struct serio_event *serio_get_event(void)
148{
149 struct serio_event *event = NULL;
150 unsigned long flags;
151
152 spin_lock_irqsave(&serio_event_lock, flags);
153
154 if (!list_empty(&serio_event_list)) {
155 event = list_first_entry(&serio_event_list,
156 struct serio_event, node);
157 list_del_init(&event->node);
158 }
159
160 spin_unlock_irqrestore(&serio_event_lock, flags);
161 return event;
162}
163
164static void serio_free_event(struct serio_event *event)
165{
166 module_put(event->owner);
167 kfree(event);
168}
169
170static void serio_remove_duplicate_events(void *object,
171 enum serio_event_type type)
172{
173 struct serio_event *e, *next;
174 unsigned long flags;
175
176 spin_lock_irqsave(&serio_event_lock, flags);
177
178 list_for_each_entry_safe(e, next, &serio_event_list, node) {
179 if (object == e->object) {
180 /*
181 * If this event is of different type we should not
182 * look further - we only suppress duplicate events
183 * that were sent back-to-back.
184 */
185 if (type != e->type)
186 break;
187
188 list_del_init(&e->node);
189 serio_free_event(e);
190 }
191 }
192
193 spin_unlock_irqrestore(&serio_event_lock, flags);
194}
195
196static void serio_handle_event(struct work_struct *work)
197{
198 struct serio_event *event;
199
200 mutex_lock(&serio_mutex);
201
202 while ((event = serio_get_event())) {
203
204 switch (event->type) {
205
206 case SERIO_REGISTER_PORT:
207 serio_add_port(event->object);
208 break;
209
210 case SERIO_RECONNECT_PORT:
211 serio_reconnect_port(event->object);
212 break;
213
214 case SERIO_RESCAN_PORT:
215 serio_disconnect_port(event->object);
216 serio_find_driver(event->object);
217 break;
218
219 case SERIO_RECONNECT_SUBTREE:
220 serio_reconnect_subtree(event->object);
221 break;
222
223 case SERIO_ATTACH_DRIVER:
224 serio_attach_driver(event->object);
225 break;
226 }
227
228 serio_remove_duplicate_events(event->object, event->type);
229 serio_free_event(event);
230 }
231
232 mutex_unlock(&serio_mutex);
233}
234
235static DECLARE_WORK(serio_event_work, serio_handle_event);
236
237static int serio_queue_event(void *object, struct module *owner,
238 enum serio_event_type event_type)
239{
240 unsigned long flags;
241 struct serio_event *event;
242 int retval = 0;
243
244 spin_lock_irqsave(&serio_event_lock, flags);
245
246 /*
247 * Scan event list for the other events for the same serio port,
248 * starting with the most recent one. If event is the same we
249 * do not need add new one. If event is of different type we
250 * need to add this event and should not look further because
251 * we need to preseve sequence of distinct events.
252 */
253 list_for_each_entry_reverse(event, &serio_event_list, node) {
254 if (event->object == object) {
255 if (event->type == event_type)
256 goto out;
257 break;
258 }
259 }
260
261 event = kmalloc(sizeof(struct serio_event), GFP_ATOMIC);
262 if (!event) {
263 pr_err("Not enough memory to queue event %d\n", event_type);
264 retval = -ENOMEM;
265 goto out;
266 }
267
268 if (!try_module_get(owner)) {
269 pr_warn("Can't get module reference, dropping event %d\n",
270 event_type);
271 kfree(event);
272 retval = -EINVAL;
273 goto out;
274 }
275
276 event->type = event_type;
277 event->object = object;
278 event->owner = owner;
279
280 list_add_tail(&event->node, &serio_event_list);
281 queue_work(system_long_wq, &serio_event_work);
282
283out:
284 spin_unlock_irqrestore(&serio_event_lock, flags);
285 return retval;
286}
287
288/*
289 * Remove all events that have been submitted for a given
290 * object, be it serio port or driver.
291 */
292static void serio_remove_pending_events(void *object)
293{
294 struct serio_event *event, *next;
295 unsigned long flags;
296
297 spin_lock_irqsave(&serio_event_lock, flags);
298
299 list_for_each_entry_safe(event, next, &serio_event_list, node) {
300 if (event->object == object) {
301 list_del_init(&event->node);
302 serio_free_event(event);
303 }
304 }
305
306 spin_unlock_irqrestore(&serio_event_lock, flags);
307}
308
309/*
310 * Locate child serio port (if any) that has not been fully registered yet.
311 *
312 * Children are registered by driver's connect() handler so there can't be a
313 * grandchild pending registration together with a child.
314 */
315static struct serio *serio_get_pending_child(struct serio *parent)
316{
317 struct serio_event *event;
318 struct serio *serio, *child = NULL;
319 unsigned long flags;
320
321 spin_lock_irqsave(&serio_event_lock, flags);
322
323 list_for_each_entry(event, &serio_event_list, node) {
324 if (event->type == SERIO_REGISTER_PORT) {
325 serio = event->object;
326 if (serio->parent == parent) {
327 child = serio;
328 break;
329 }
330 }
331 }
332
333 spin_unlock_irqrestore(&serio_event_lock, flags);
334 return child;
335}
336
337/*
338 * Serio port operations
339 */
340
341static ssize_t serio_show_description(struct device *dev, struct device_attribute *attr, char *buf)
342{
343 struct serio *serio = to_serio_port(dev);
344 return sprintf(buf, "%s\n", serio->name);
345}
346
347static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, char *buf)
348{
349 struct serio *serio = to_serio_port(dev);
350
351 return sprintf(buf, "serio:ty%02Xpr%02Xid%02Xex%02X\n",
352 serio->id.type, serio->id.proto, serio->id.id, serio->id.extra);
353}
354
355static ssize_t type_show(struct device *dev, struct device_attribute *attr, char *buf)
356{
357 struct serio *serio = to_serio_port(dev);
358 return sprintf(buf, "%02x\n", serio->id.type);
359}
360
361static ssize_t proto_show(struct device *dev, struct device_attribute *attr, char *buf)
362{
363 struct serio *serio = to_serio_port(dev);
364 return sprintf(buf, "%02x\n", serio->id.proto);
365}
366
367static ssize_t id_show(struct device *dev, struct device_attribute *attr, char *buf)
368{
369 struct serio *serio = to_serio_port(dev);
370 return sprintf(buf, "%02x\n", serio->id.id);
371}
372
373static ssize_t extra_show(struct device *dev, struct device_attribute *attr, char *buf)
374{
375 struct serio *serio = to_serio_port(dev);
376 return sprintf(buf, "%02x\n", serio->id.extra);
377}
378
379static ssize_t drvctl_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
380{
381 struct serio *serio = to_serio_port(dev);
382 struct device_driver *drv;
383 int error;
384
385 error = mutex_lock_interruptible(&serio_mutex);
386 if (error)
387 return error;
388
389 if (!strncmp(buf, "none", count)) {
390 serio_disconnect_port(serio);
391 } else if (!strncmp(buf, "reconnect", count)) {
392 serio_reconnect_subtree(serio);
393 } else if (!strncmp(buf, "rescan", count)) {
394 serio_disconnect_port(serio);
395 serio_find_driver(serio);
396 serio_remove_duplicate_events(serio, SERIO_RESCAN_PORT);
397 } else if ((drv = driver_find(buf, &serio_bus)) != NULL) {
398 serio_disconnect_port(serio);
399 error = serio_bind_driver(serio, to_serio_driver(drv));
400 serio_remove_duplicate_events(serio, SERIO_RESCAN_PORT);
401 } else {
402 error = -EINVAL;
403 }
404
405 mutex_unlock(&serio_mutex);
406
407 return error ? error : count;
408}
409
410static ssize_t serio_show_bind_mode(struct device *dev, struct device_attribute *attr, char *buf)
411{
412 struct serio *serio = to_serio_port(dev);
413 return sprintf(buf, "%s\n", serio->manual_bind ? "manual" : "auto");
414}
415
416static ssize_t serio_set_bind_mode(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
417{
418 struct serio *serio = to_serio_port(dev);
419 int retval;
420
421 retval = count;
422 if (!strncmp(buf, "manual", count)) {
423 serio->manual_bind = true;
424 } else if (!strncmp(buf, "auto", count)) {
425 serio->manual_bind = false;
426 } else {
427 retval = -EINVAL;
428 }
429
430 return retval;
431}
432
433static ssize_t firmware_id_show(struct device *dev, struct device_attribute *attr, char *buf)
434{
435 struct serio *serio = to_serio_port(dev);
436
437 return sprintf(buf, "%s\n", serio->firmware_id);
438}
439
440static DEVICE_ATTR_RO(type);
441static DEVICE_ATTR_RO(proto);
442static DEVICE_ATTR_RO(id);
443static DEVICE_ATTR_RO(extra);
444
445static struct attribute *serio_device_id_attrs[] = {
446 &dev_attr_type.attr,
447 &dev_attr_proto.attr,
448 &dev_attr_id.attr,
449 &dev_attr_extra.attr,
450 NULL
451};
452
453static const struct attribute_group serio_id_attr_group = {
454 .name = "id",
455 .attrs = serio_device_id_attrs,
456};
457
458static DEVICE_ATTR_RO(modalias);
459static DEVICE_ATTR_WO(drvctl);
460static DEVICE_ATTR(description, S_IRUGO, serio_show_description, NULL);
461static DEVICE_ATTR(bind_mode, S_IWUSR | S_IRUGO, serio_show_bind_mode, serio_set_bind_mode);
462static DEVICE_ATTR_RO(firmware_id);
463
464static struct attribute *serio_device_attrs[] = {
465 &dev_attr_modalias.attr,
466 &dev_attr_description.attr,
467 &dev_attr_drvctl.attr,
468 &dev_attr_bind_mode.attr,
469 &dev_attr_firmware_id.attr,
470 NULL
471};
472
473static const struct attribute_group serio_device_attr_group = {
474 .attrs = serio_device_attrs,
475};
476
477static const struct attribute_group *serio_device_attr_groups[] = {
478 &serio_id_attr_group,
479 &serio_device_attr_group,
480 NULL
481};
482
483static void serio_release_port(struct device *dev)
484{
485 struct serio *serio = to_serio_port(dev);
486
487 kfree(serio);
488 module_put(THIS_MODULE);
489}
490
491/*
492 * Prepare serio port for registration.
493 */
494static void serio_init_port(struct serio *serio)
495{
496 static atomic_t serio_no = ATOMIC_INIT(-1);
497
498 __module_get(THIS_MODULE);
499
500 INIT_LIST_HEAD(&serio->node);
501 INIT_LIST_HEAD(&serio->child_node);
502 INIT_LIST_HEAD(&serio->children);
503 spin_lock_init(&serio->lock);
504 mutex_init(&serio->drv_mutex);
505 device_initialize(&serio->dev);
506 dev_set_name(&serio->dev, "serio%lu",
507 (unsigned long)atomic_inc_return(&serio_no));
508 serio->dev.bus = &serio_bus;
509 serio->dev.release = serio_release_port;
510 serio->dev.groups = serio_device_attr_groups;
511 if (serio->parent) {
512 serio->dev.parent = &serio->parent->dev;
513 serio->depth = serio->parent->depth + 1;
514 } else
515 serio->depth = 0;
516 lockdep_set_subclass(&serio->lock, serio->depth);
517}
518
519/*
520 * Complete serio port registration.
521 * Driver core will attempt to find appropriate driver for the port.
522 */
523static void serio_add_port(struct serio *serio)
524{
525 struct serio *parent = serio->parent;
526 int error;
527
528 if (parent) {
529 serio_pause_rx(parent);
530 list_add_tail(&serio->child_node, &parent->children);
531 serio_continue_rx(parent);
532 }
533
534 list_add_tail(&serio->node, &serio_list);
535
536 if (serio->start)
537 serio->start(serio);
538
539 error = device_add(&serio->dev);
540 if (error)
541 dev_err(&serio->dev,
542 "device_add() failed for %s (%s), error: %d\n",
543 serio->phys, serio->name, error);
544}
545
546/*
547 * serio_destroy_port() completes unregistration process and removes
548 * port from the system
549 */
550static void serio_destroy_port(struct serio *serio)
551{
552 struct serio *child;
553
554 while ((child = serio_get_pending_child(serio)) != NULL) {
555 serio_remove_pending_events(child);
556 put_device(&child->dev);
557 }
558
559 if (serio->stop)
560 serio->stop(serio);
561
562 if (serio->parent) {
563 serio_pause_rx(serio->parent);
564 list_del_init(&serio->child_node);
565 serio_continue_rx(serio->parent);
566 serio->parent = NULL;
567 }
568
569 if (device_is_registered(&serio->dev))
570 device_del(&serio->dev);
571
572 list_del_init(&serio->node);
573 serio_remove_pending_events(serio);
574 put_device(&serio->dev);
575}
576
577/*
578 * Reconnect serio port (re-initialize attached device).
579 * If reconnect fails (old device is no longer attached or
580 * there was no device to begin with) we do full rescan in
581 * hope of finding a driver for the port.
582 */
583static int serio_reconnect_port(struct serio *serio)
584{
585 int error = serio_reconnect_driver(serio);
586
587 if (error) {
588 serio_disconnect_port(serio);
589 serio_find_driver(serio);
590 }
591
592 return error;
593}
594
595/*
596 * Reconnect serio port and all its children (re-initialize attached
597 * devices).
598 */
599static void serio_reconnect_subtree(struct serio *root)
600{
601 struct serio *s = root;
602 int error;
603
604 do {
605 error = serio_reconnect_port(s);
606 if (!error) {
607 /*
608 * Reconnect was successful, move on to do the
609 * first child.
610 */
611 if (!list_empty(&s->children)) {
612 s = list_first_entry(&s->children,
613 struct serio, child_node);
614 continue;
615 }
616 }
617
618 /*
619 * Either it was a leaf node or reconnect failed and it
620 * became a leaf node. Continue reconnecting starting with
621 * the next sibling of the parent node.
622 */
623 while (s != root) {
624 struct serio *parent = s->parent;
625
626 if (!list_is_last(&s->child_node, &parent->children)) {
627 s = list_entry(s->child_node.next,
628 struct serio, child_node);
629 break;
630 }
631
632 s = parent;
633 }
634 } while (s != root);
635}
636
637/*
638 * serio_disconnect_port() unbinds a port from its driver. As a side effect
639 * all children ports are unbound and destroyed.
640 */
641static void serio_disconnect_port(struct serio *serio)
642{
643 struct serio *s = serio;
644
645 /*
646 * Children ports should be disconnected and destroyed
647 * first; we travel the tree in depth-first order.
648 */
649 while (!list_empty(&serio->children)) {
650
651 /* Locate a leaf */
652 while (!list_empty(&s->children))
653 s = list_first_entry(&s->children,
654 struct serio, child_node);
655
656 /*
657 * Prune this leaf node unless it is the one we
658 * started with.
659 */
660 if (s != serio) {
661 struct serio *parent = s->parent;
662
663 device_release_driver(&s->dev);
664 serio_destroy_port(s);
665
666 s = parent;
667 }
668 }
669
670 /*
671 * OK, no children left, now disconnect this port.
672 */
673 device_release_driver(&serio->dev);
674}
675
676void serio_rescan(struct serio *serio)
677{
678 serio_queue_event(serio, NULL, SERIO_RESCAN_PORT);
679}
680EXPORT_SYMBOL(serio_rescan);
681
682void serio_reconnect(struct serio *serio)
683{
684 serio_queue_event(serio, NULL, SERIO_RECONNECT_SUBTREE);
685}
686EXPORT_SYMBOL(serio_reconnect);
687
688/*
689 * Submits register request to kseriod for subsequent execution.
690 * Note that port registration is always asynchronous.
691 */
692void __serio_register_port(struct serio *serio, struct module *owner)
693{
694 serio_init_port(serio);
695 serio_queue_event(serio, owner, SERIO_REGISTER_PORT);
696}
697EXPORT_SYMBOL(__serio_register_port);
698
699/*
700 * Synchronously unregisters serio port.
701 */
702void serio_unregister_port(struct serio *serio)
703{
704 mutex_lock(&serio_mutex);
705 serio_disconnect_port(serio);
706 serio_destroy_port(serio);
707 mutex_unlock(&serio_mutex);
708}
709EXPORT_SYMBOL(serio_unregister_port);
710
711/*
712 * Safely unregisters children ports if they are present.
713 */
714void serio_unregister_child_port(struct serio *serio)
715{
716 struct serio *s, *next;
717
718 mutex_lock(&serio_mutex);
719 list_for_each_entry_safe(s, next, &serio->children, child_node) {
720 serio_disconnect_port(s);
721 serio_destroy_port(s);
722 }
723 mutex_unlock(&serio_mutex);
724}
725EXPORT_SYMBOL(serio_unregister_child_port);
726
727
728/*
729 * Serio driver operations
730 */
731
732static ssize_t description_show(struct device_driver *drv, char *buf)
733{
734 struct serio_driver *driver = to_serio_driver(drv);
735 return sprintf(buf, "%s\n", driver->description ? driver->description : "(none)");
736}
737static DRIVER_ATTR_RO(description);
738
739static ssize_t bind_mode_show(struct device_driver *drv, char *buf)
740{
741 struct serio_driver *serio_drv = to_serio_driver(drv);
742 return sprintf(buf, "%s\n", serio_drv->manual_bind ? "manual" : "auto");
743}
744
745static ssize_t bind_mode_store(struct device_driver *drv, const char *buf, size_t count)
746{
747 struct serio_driver *serio_drv = to_serio_driver(drv);
748 int retval;
749
750 retval = count;
751 if (!strncmp(buf, "manual", count)) {
752 serio_drv->manual_bind = true;
753 } else if (!strncmp(buf, "auto", count)) {
754 serio_drv->manual_bind = false;
755 } else {
756 retval = -EINVAL;
757 }
758
759 return retval;
760}
761static DRIVER_ATTR_RW(bind_mode);
762
763static struct attribute *serio_driver_attrs[] = {
764 &driver_attr_description.attr,
765 &driver_attr_bind_mode.attr,
766 NULL,
767};
768ATTRIBUTE_GROUPS(serio_driver);
769
770static int serio_driver_probe(struct device *dev)
771{
772 struct serio *serio = to_serio_port(dev);
773 struct serio_driver *drv = to_serio_driver(dev->driver);
774
775 return serio_connect_driver(serio, drv);
776}
777
778static void serio_driver_remove(struct device *dev)
779{
780 struct serio *serio = to_serio_port(dev);
781
782 serio_disconnect_driver(serio);
783}
784
785static void serio_cleanup(struct serio *serio)
786{
787 mutex_lock(&serio->drv_mutex);
788 if (serio->drv && serio->drv->cleanup)
789 serio->drv->cleanup(serio);
790 mutex_unlock(&serio->drv_mutex);
791}
792
793static void serio_shutdown(struct device *dev)
794{
795 struct serio *serio = to_serio_port(dev);
796
797 serio_cleanup(serio);
798}
799
800static void serio_attach_driver(struct serio_driver *drv)
801{
802 int error;
803
804 error = driver_attach(&drv->driver);
805 if (error)
806 pr_warn("driver_attach() failed for %s with error %d\n",
807 drv->driver.name, error);
808}
809
810int __serio_register_driver(struct serio_driver *drv, struct module *owner, const char *mod_name)
811{
812 bool manual_bind = drv->manual_bind;
813 int error;
814
815 drv->driver.bus = &serio_bus;
816 drv->driver.owner = owner;
817 drv->driver.mod_name = mod_name;
818
819 /*
820 * Temporarily disable automatic binding because probing
821 * takes long time and we are better off doing it in kseriod
822 */
823 drv->manual_bind = true;
824
825 error = driver_register(&drv->driver);
826 if (error) {
827 pr_err("driver_register() failed for %s, error: %d\n",
828 drv->driver.name, error);
829 return error;
830 }
831
832 /*
833 * Restore original bind mode and let kseriod bind the
834 * driver to free ports
835 */
836 if (!manual_bind) {
837 drv->manual_bind = false;
838 error = serio_queue_event(drv, NULL, SERIO_ATTACH_DRIVER);
839 if (error) {
840 driver_unregister(&drv->driver);
841 return error;
842 }
843 }
844
845 return 0;
846}
847EXPORT_SYMBOL(__serio_register_driver);
848
849void serio_unregister_driver(struct serio_driver *drv)
850{
851 struct serio *serio;
852
853 mutex_lock(&serio_mutex);
854
855 drv->manual_bind = true; /* so serio_find_driver ignores it */
856 serio_remove_pending_events(drv);
857
858start_over:
859 list_for_each_entry(serio, &serio_list, node) {
860 if (serio->drv == drv) {
861 serio_disconnect_port(serio);
862 serio_find_driver(serio);
863 /* we could've deleted some ports, restart */
864 goto start_over;
865 }
866 }
867
868 driver_unregister(&drv->driver);
869 mutex_unlock(&serio_mutex);
870}
871EXPORT_SYMBOL(serio_unregister_driver);
872
873static void serio_set_drv(struct serio *serio, struct serio_driver *drv)
874{
875 serio_pause_rx(serio);
876 serio->drv = drv;
877 serio_continue_rx(serio);
878}
879
880static int serio_bus_match(struct device *dev, struct device_driver *drv)
881{
882 struct serio *serio = to_serio_port(dev);
883 struct serio_driver *serio_drv = to_serio_driver(drv);
884
885 if (serio->manual_bind || serio_drv->manual_bind)
886 return 0;
887
888 return serio_match_port(serio_drv->id_table, serio);
889}
890
891#define SERIO_ADD_UEVENT_VAR(fmt, val...) \
892 do { \
893 int err = add_uevent_var(env, fmt, val); \
894 if (err) \
895 return err; \
896 } while (0)
897
898static int serio_uevent(const struct device *dev, struct kobj_uevent_env *env)
899{
900 const struct serio *serio;
901
902 if (!dev)
903 return -ENODEV;
904
905 serio = to_serio_port(dev);
906
907 SERIO_ADD_UEVENT_VAR("SERIO_TYPE=%02x", serio->id.type);
908 SERIO_ADD_UEVENT_VAR("SERIO_PROTO=%02x", serio->id.proto);
909 SERIO_ADD_UEVENT_VAR("SERIO_ID=%02x", serio->id.id);
910 SERIO_ADD_UEVENT_VAR("SERIO_EXTRA=%02x", serio->id.extra);
911
912 SERIO_ADD_UEVENT_VAR("MODALIAS=serio:ty%02Xpr%02Xid%02Xex%02X",
913 serio->id.type, serio->id.proto, serio->id.id, serio->id.extra);
914
915 if (serio->firmware_id[0])
916 SERIO_ADD_UEVENT_VAR("SERIO_FIRMWARE_ID=%s",
917 serio->firmware_id);
918
919 return 0;
920}
921#undef SERIO_ADD_UEVENT_VAR
922
923#ifdef CONFIG_PM
924static int serio_suspend(struct device *dev)
925{
926 struct serio *serio = to_serio_port(dev);
927
928 serio_cleanup(serio);
929
930 return 0;
931}
932
933static int serio_resume(struct device *dev)
934{
935 struct serio *serio = to_serio_port(dev);
936 int error = -ENOENT;
937
938 mutex_lock(&serio->drv_mutex);
939 if (serio->drv && serio->drv->fast_reconnect) {
940 error = serio->drv->fast_reconnect(serio);
941 if (error && error != -ENOENT)
942 dev_warn(dev, "fast reconnect failed with error %d\n",
943 error);
944 }
945 mutex_unlock(&serio->drv_mutex);
946
947 if (error) {
948 /*
949 * Driver reconnect can take a while, so better let
950 * kseriod deal with it.
951 */
952 serio_queue_event(serio, NULL, SERIO_RECONNECT_PORT);
953 }
954
955 return 0;
956}
957
958static const struct dev_pm_ops serio_pm_ops = {
959 .suspend = serio_suspend,
960 .resume = serio_resume,
961 .poweroff = serio_suspend,
962 .restore = serio_resume,
963};
964#endif /* CONFIG_PM */
965
966/* called from serio_driver->connect/disconnect methods under serio_mutex */
967int serio_open(struct serio *serio, struct serio_driver *drv)
968{
969 serio_set_drv(serio, drv);
970
971 if (serio->open && serio->open(serio)) {
972 serio_set_drv(serio, NULL);
973 return -1;
974 }
975 return 0;
976}
977EXPORT_SYMBOL(serio_open);
978
979/* called from serio_driver->connect/disconnect methods under serio_mutex */
980void serio_close(struct serio *serio)
981{
982 if (serio->close)
983 serio->close(serio);
984
985 serio_set_drv(serio, NULL);
986}
987EXPORT_SYMBOL(serio_close);
988
989irqreturn_t serio_interrupt(struct serio *serio,
990 unsigned char data, unsigned int dfl)
991{
992 unsigned long flags;
993 irqreturn_t ret = IRQ_NONE;
994
995 spin_lock_irqsave(&serio->lock, flags);
996
997 if (likely(serio->drv)) {
998 ret = serio->drv->interrupt(serio, data, dfl);
999 } else if (!dfl && device_is_registered(&serio->dev)) {
1000 serio_rescan(serio);
1001 ret = IRQ_HANDLED;
1002 }
1003
1004 spin_unlock_irqrestore(&serio->lock, flags);
1005
1006 return ret;
1007}
1008EXPORT_SYMBOL(serio_interrupt);
1009
1010struct bus_type serio_bus = {
1011 .name = "serio",
1012 .drv_groups = serio_driver_groups,
1013 .match = serio_bus_match,
1014 .uevent = serio_uevent,
1015 .probe = serio_driver_probe,
1016 .remove = serio_driver_remove,
1017 .shutdown = serio_shutdown,
1018#ifdef CONFIG_PM
1019 .pm = &serio_pm_ops,
1020#endif
1021};
1022EXPORT_SYMBOL(serio_bus);
1023
1024static int __init serio_init(void)
1025{
1026 int error;
1027
1028 error = bus_register(&serio_bus);
1029 if (error) {
1030 pr_err("Failed to register serio bus, error: %d\n", error);
1031 return error;
1032 }
1033
1034 return 0;
1035}
1036
1037static void __exit serio_exit(void)
1038{
1039 bus_unregister(&serio_bus);
1040
1041 /*
1042 * There should not be any outstanding events but work may
1043 * still be scheduled so simply cancel it.
1044 */
1045 cancel_work_sync(&serio_event_work);
1046}
1047
1048subsys_initcall(serio_init);
1049module_exit(serio_exit);