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

source code of linux/drivers/input/serio/serio.c