Line data Source code
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 :
21 : MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
22 : MODULE_DESCRIPTION("Serio abstraction core");
23 : MODULE_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 : */
29 : static DEFINE_MUTEX(serio_mutex);
30 :
31 : static LIST_HEAD(serio_list);
32 :
33 : static void serio_add_port(struct serio *serio);
34 : static int serio_reconnect_port(struct serio *serio);
35 : static void serio_disconnect_port(struct serio *serio);
36 : static void serio_reconnect_subtree(struct serio *serio);
37 : static void serio_attach_driver(struct serio_driver *drv);
38 :
39 0 : static int serio_connect_driver(struct serio *serio, struct serio_driver *drv)
40 : {
41 : int retval;
42 :
43 0 : mutex_lock(&serio->drv_mutex);
44 0 : retval = drv->connect(serio, drv);
45 0 : mutex_unlock(&serio->drv_mutex);
46 :
47 0 : return retval;
48 : }
49 :
50 0 : static int serio_reconnect_driver(struct serio *serio)
51 : {
52 0 : int retval = -1;
53 :
54 0 : mutex_lock(&serio->drv_mutex);
55 0 : if (serio->drv && serio->drv->reconnect)
56 0 : retval = serio->drv->reconnect(serio);
57 0 : mutex_unlock(&serio->drv_mutex);
58 :
59 0 : return retval;
60 : }
61 :
62 0 : static void serio_disconnect_driver(struct serio *serio)
63 : {
64 0 : mutex_lock(&serio->drv_mutex);
65 0 : if (serio->drv)
66 0 : serio->drv->disconnect(serio);
67 0 : mutex_unlock(&serio->drv_mutex);
68 0 : }
69 :
70 0 : static int serio_match_port(const struct serio_device_id *ids, struct serio *serio)
71 : {
72 0 : while (ids->type || ids->proto) {
73 0 : if ((ids->type == SERIO_ANY || ids->type == serio->id.type) &&
74 0 : (ids->proto == SERIO_ANY || ids->proto == serio->id.proto) &&
75 0 : (ids->extra == SERIO_ANY || ids->extra == serio->id.extra) &&
76 0 : (ids->id == SERIO_ANY || ids->id == serio->id.id))
77 : return 1;
78 0 : ids++;
79 : }
80 : return 0;
81 : }
82 :
83 : /*
84 : * Basic serio -> driver core mappings
85 : */
86 :
87 0 : static int serio_bind_driver(struct serio *serio, struct serio_driver *drv)
88 : {
89 : int error;
90 :
91 0 : if (serio_match_port(drv->id_table, serio)) {
92 :
93 0 : serio->dev.driver = &drv->driver;
94 0 : if (serio_connect_driver(serio, drv)) {
95 0 : serio->dev.driver = NULL;
96 0 : return -ENODEV;
97 : }
98 :
99 0 : error = device_bind_driver(&serio->dev);
100 0 : if (error) {
101 0 : 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 0 : serio_disconnect_driver(serio);
106 0 : serio->dev.driver = NULL;
107 0 : return error;
108 : }
109 : }
110 : return 0;
111 : }
112 :
113 0 : static void serio_find_driver(struct serio *serio)
114 : {
115 : int error;
116 :
117 0 : error = device_attach(&serio->dev);
118 0 : if (error < 0 && error != -EPROBE_DEFER)
119 0 : dev_warn(&serio->dev,
120 : "device_attach() failed for %s (%s), error: %d\n",
121 : serio->phys, serio->name, error);
122 0 : }
123 :
124 :
125 : /*
126 : * Serio event processing.
127 : */
128 :
129 : enum 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 :
137 : struct serio_event {
138 : enum serio_event_type type;
139 : void *object;
140 : struct module *owner;
141 : struct list_head node;
142 : };
143 :
144 : static DEFINE_SPINLOCK(serio_event_lock); /* protects serio_event_list */
145 : static LIST_HEAD(serio_event_list);
146 :
147 3 : static struct serio_event *serio_get_event(void)
148 : {
149 3 : struct serio_event *event = NULL;
150 : unsigned long flags;
151 :
152 3 : spin_lock_irqsave(&serio_event_lock, flags);
153 :
154 3 : if (!list_empty(&serio_event_list)) {
155 2 : event = list_first_entry(&serio_event_list,
156 : struct serio_event, node);
157 2 : list_del_init(&event->node);
158 : }
159 :
160 3 : spin_unlock_irqrestore(&serio_event_lock, flags);
161 3 : return event;
162 : }
163 :
164 : static void serio_free_event(struct serio_event *event)
165 : {
166 2 : module_put(event->owner);
167 2 : kfree(event);
168 : }
169 :
170 2 : static 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 2 : spin_lock_irqsave(&serio_event_lock, flags);
177 :
178 3 : list_for_each_entry_safe(e, next, &serio_event_list, node) {
179 1 : 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 0 : if (type != e->type)
186 : break;
187 :
188 0 : list_del_init(&e->node);
189 : serio_free_event(e);
190 : }
191 : }
192 :
193 2 : spin_unlock_irqrestore(&serio_event_lock, flags);
194 2 : }
195 :
196 1 : static void serio_handle_event(struct work_struct *work)
197 : {
198 : struct serio_event *event;
199 :
200 1 : mutex_lock(&serio_mutex);
201 :
202 4 : while ((event = serio_get_event())) {
203 :
204 2 : switch (event->type) {
205 :
206 : case SERIO_REGISTER_PORT:
207 0 : serio_add_port(event->object);
208 0 : break;
209 :
210 : case SERIO_RECONNECT_PORT:
211 0 : serio_reconnect_port(event->object);
212 0 : break;
213 :
214 : case SERIO_RESCAN_PORT:
215 0 : serio_disconnect_port(event->object);
216 0 : serio_find_driver(event->object);
217 0 : break;
218 :
219 : case SERIO_RECONNECT_SUBTREE:
220 0 : serio_reconnect_subtree(event->object);
221 0 : break;
222 :
223 : case SERIO_ATTACH_DRIVER:
224 2 : serio_attach_driver(event->object);
225 2 : break;
226 : }
227 :
228 2 : serio_remove_duplicate_events(event->object, event->type);
229 : serio_free_event(event);
230 : }
231 :
232 1 : mutex_unlock(&serio_mutex);
233 1 : }
234 :
235 : static DECLARE_WORK(serio_event_work, serio_handle_event);
236 :
237 2 : static 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 2 : int retval = 0;
243 :
244 2 : 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 3 : list_for_each_entry_reverse(event, &serio_event_list, node) {
254 1 : if (event->object == object) {
255 0 : if (event->type == event_type)
256 : goto out;
257 : break;
258 : }
259 : }
260 :
261 2 : event = kmalloc(sizeof(struct serio_event), GFP_ATOMIC);
262 2 : if (!event) {
263 0 : pr_err("Not enough memory to queue event %d\n", event_type);
264 0 : retval = -ENOMEM;
265 0 : goto out;
266 : }
267 :
268 2 : 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 2 : event->type = event_type;
277 2 : event->object = object;
278 2 : event->owner = owner;
279 :
280 4 : list_add_tail(&event->node, &serio_event_list);
281 2 : queue_work(system_long_wq, &serio_event_work);
282 :
283 : out:
284 2 : spin_unlock_irqrestore(&serio_event_lock, flags);
285 2 : 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 : */
292 0 : static void serio_remove_pending_events(void *object)
293 : {
294 : struct serio_event *event, *next;
295 : unsigned long flags;
296 :
297 0 : spin_lock_irqsave(&serio_event_lock, flags);
298 :
299 0 : list_for_each_entry_safe(event, next, &serio_event_list, node) {
300 0 : if (event->object == object) {
301 0 : list_del_init(&event->node);
302 : serio_free_event(event);
303 : }
304 : }
305 :
306 0 : spin_unlock_irqrestore(&serio_event_lock, flags);
307 0 : }
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 : */
315 0 : static struct serio *serio_get_pending_child(struct serio *parent)
316 : {
317 : struct serio_event *event;
318 0 : struct serio *serio, *child = NULL;
319 : unsigned long flags;
320 :
321 0 : spin_lock_irqsave(&serio_event_lock, flags);
322 :
323 0 : list_for_each_entry(event, &serio_event_list, node) {
324 0 : if (event->type == SERIO_REGISTER_PORT) {
325 0 : serio = event->object;
326 0 : if (serio->parent == parent) {
327 : child = serio;
328 : break;
329 : }
330 : }
331 : }
332 :
333 0 : spin_unlock_irqrestore(&serio_event_lock, flags);
334 0 : return child;
335 : }
336 :
337 : /*
338 : * Serio port operations
339 : */
340 :
341 0 : static ssize_t serio_show_description(struct device *dev, struct device_attribute *attr, char *buf)
342 : {
343 0 : struct serio *serio = to_serio_port(dev);
344 0 : return sprintf(buf, "%s\n", serio->name);
345 : }
346 :
347 0 : static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, char *buf)
348 : {
349 0 : struct serio *serio = to_serio_port(dev);
350 :
351 0 : return sprintf(buf, "serio:ty%02Xpr%02Xid%02Xex%02X\n",
352 0 : serio->id.type, serio->id.proto, serio->id.id, serio->id.extra);
353 : }
354 :
355 0 : static ssize_t type_show(struct device *dev, struct device_attribute *attr, char *buf)
356 : {
357 0 : struct serio *serio = to_serio_port(dev);
358 0 : return sprintf(buf, "%02x\n", serio->id.type);
359 : }
360 :
361 0 : static ssize_t proto_show(struct device *dev, struct device_attribute *attr, char *buf)
362 : {
363 0 : struct serio *serio = to_serio_port(dev);
364 0 : return sprintf(buf, "%02x\n", serio->id.proto);
365 : }
366 :
367 0 : static ssize_t id_show(struct device *dev, struct device_attribute *attr, char *buf)
368 : {
369 0 : struct serio *serio = to_serio_port(dev);
370 0 : return sprintf(buf, "%02x\n", serio->id.id);
371 : }
372 :
373 0 : static ssize_t extra_show(struct device *dev, struct device_attribute *attr, char *buf)
374 : {
375 0 : struct serio *serio = to_serio_port(dev);
376 0 : return sprintf(buf, "%02x\n", serio->id.extra);
377 : }
378 :
379 0 : static ssize_t drvctl_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
380 : {
381 0 : struct serio *serio = to_serio_port(dev);
382 : struct device_driver *drv;
383 : int error;
384 :
385 0 : error = mutex_lock_interruptible(&serio_mutex);
386 0 : if (error)
387 0 : return error;
388 :
389 0 : if (!strncmp(buf, "none", count)) {
390 0 : serio_disconnect_port(serio);
391 0 : } else if (!strncmp(buf, "reconnect", count)) {
392 0 : serio_reconnect_subtree(serio);
393 0 : } else if (!strncmp(buf, "rescan", count)) {
394 0 : serio_disconnect_port(serio);
395 0 : serio_find_driver(serio);
396 0 : serio_remove_duplicate_events(serio, SERIO_RESCAN_PORT);
397 0 : } else if ((drv = driver_find(buf, &serio_bus)) != NULL) {
398 0 : serio_disconnect_port(serio);
399 0 : error = serio_bind_driver(serio, to_serio_driver(drv));
400 0 : serio_remove_duplicate_events(serio, SERIO_RESCAN_PORT);
401 : } else {
402 : error = -EINVAL;
403 : }
404 :
405 0 : mutex_unlock(&serio_mutex);
406 :
407 0 : return error ? error : count;
408 : }
409 :
410 0 : static ssize_t serio_show_bind_mode(struct device *dev, struct device_attribute *attr, char *buf)
411 : {
412 0 : struct serio *serio = to_serio_port(dev);
413 0 : return sprintf(buf, "%s\n", serio->manual_bind ? "manual" : "auto");
414 : }
415 :
416 0 : static ssize_t serio_set_bind_mode(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
417 : {
418 0 : struct serio *serio = to_serio_port(dev);
419 : int retval;
420 :
421 0 : retval = count;
422 0 : if (!strncmp(buf, "manual", count)) {
423 0 : serio->manual_bind = true;
424 0 : } else if (!strncmp(buf, "auto", count)) {
425 0 : serio->manual_bind = false;
426 : } else {
427 : retval = -EINVAL;
428 : }
429 :
430 0 : return retval;
431 : }
432 :
433 0 : static ssize_t firmware_id_show(struct device *dev, struct device_attribute *attr, char *buf)
434 : {
435 0 : struct serio *serio = to_serio_port(dev);
436 :
437 0 : return sprintf(buf, "%s\n", serio->firmware_id);
438 : }
439 :
440 : static DEVICE_ATTR_RO(type);
441 : static DEVICE_ATTR_RO(proto);
442 : static DEVICE_ATTR_RO(id);
443 : static DEVICE_ATTR_RO(extra);
444 :
445 : static 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 :
453 : static const struct attribute_group serio_id_attr_group = {
454 : .name = "id",
455 : .attrs = serio_device_id_attrs,
456 : };
457 :
458 : static DEVICE_ATTR_RO(modalias);
459 : static DEVICE_ATTR_WO(drvctl);
460 : static DEVICE_ATTR(description, S_IRUGO, serio_show_description, NULL);
461 : static DEVICE_ATTR(bind_mode, S_IWUSR | S_IRUGO, serio_show_bind_mode, serio_set_bind_mode);
462 : static DEVICE_ATTR_RO(firmware_id);
463 :
464 : static 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 :
473 : static const struct attribute_group serio_device_attr_group = {
474 : .attrs = serio_device_attrs,
475 : };
476 :
477 : static const struct attribute_group *serio_device_attr_groups[] = {
478 : &serio_id_attr_group,
479 : &serio_device_attr_group,
480 : NULL
481 : };
482 :
483 0 : static void serio_release_port(struct device *dev)
484 : {
485 0 : struct serio *serio = to_serio_port(dev);
486 :
487 0 : kfree(serio);
488 0 : module_put(THIS_MODULE);
489 0 : }
490 :
491 : /*
492 : * Prepare serio port for registration.
493 : */
494 0 : static void serio_init_port(struct serio *serio)
495 : {
496 : static atomic_t serio_no = ATOMIC_INIT(-1);
497 :
498 0 : __module_get(THIS_MODULE);
499 :
500 0 : INIT_LIST_HEAD(&serio->node);
501 0 : INIT_LIST_HEAD(&serio->child_node);
502 0 : INIT_LIST_HEAD(&serio->children);
503 0 : spin_lock_init(&serio->lock);
504 0 : mutex_init(&serio->drv_mutex);
505 0 : device_initialize(&serio->dev);
506 0 : dev_set_name(&serio->dev, "serio%lu",
507 0 : (unsigned long)atomic_inc_return(&serio_no));
508 0 : serio->dev.bus = &serio_bus;
509 0 : serio->dev.release = serio_release_port;
510 0 : serio->dev.groups = serio_device_attr_groups;
511 0 : if (serio->parent) {
512 0 : serio->dev.parent = &serio->parent->dev;
513 0 : serio->depth = serio->parent->depth + 1;
514 : } else
515 0 : serio->depth = 0;
516 : lockdep_set_subclass(&serio->lock, serio->depth);
517 0 : }
518 :
519 : /*
520 : * Complete serio port registration.
521 : * Driver core will attempt to find appropriate driver for the port.
522 : */
523 0 : static void serio_add_port(struct serio *serio)
524 : {
525 0 : struct serio *parent = serio->parent;
526 : int error;
527 :
528 0 : if (parent) {
529 0 : serio_pause_rx(parent);
530 0 : list_add_tail(&serio->child_node, &parent->children);
531 0 : serio_continue_rx(parent);
532 : }
533 :
534 0 : list_add_tail(&serio->node, &serio_list);
535 :
536 0 : if (serio->start)
537 0 : serio->start(serio);
538 :
539 0 : error = device_add(&serio->dev);
540 0 : if (error)
541 0 : dev_err(&serio->dev,
542 : "device_add() failed for %s (%s), error: %d\n",
543 : serio->phys, serio->name, error);
544 0 : }
545 :
546 : /*
547 : * serio_destroy_port() completes unregistration process and removes
548 : * port from the system
549 : */
550 0 : static void serio_destroy_port(struct serio *serio)
551 : {
552 : struct serio *child;
553 :
554 0 : while ((child = serio_get_pending_child(serio)) != NULL) {
555 0 : serio_remove_pending_events(child);
556 0 : put_device(&child->dev);
557 : }
558 :
559 0 : if (serio->stop)
560 0 : serio->stop(serio);
561 :
562 0 : if (serio->parent) {
563 0 : serio_pause_rx(serio->parent);
564 0 : list_del_init(&serio->child_node);
565 0 : serio_continue_rx(serio->parent);
566 0 : serio->parent = NULL;
567 : }
568 :
569 0 : if (device_is_registered(&serio->dev))
570 0 : device_del(&serio->dev);
571 :
572 0 : list_del_init(&serio->node);
573 0 : serio_remove_pending_events(serio);
574 0 : put_device(&serio->dev);
575 0 : }
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 : */
583 0 : static int serio_reconnect_port(struct serio *serio)
584 : {
585 0 : int error = serio_reconnect_driver(serio);
586 :
587 0 : if (error) {
588 0 : serio_disconnect_port(serio);
589 0 : serio_find_driver(serio);
590 : }
591 :
592 0 : return error;
593 : }
594 :
595 : /*
596 : * Reconnect serio port and all its children (re-initialize attached
597 : * devices).
598 : */
599 0 : static void serio_reconnect_subtree(struct serio *root)
600 : {
601 0 : struct serio *s = root;
602 : int error;
603 :
604 : do {
605 0 : error = serio_reconnect_port(s);
606 0 : if (!error) {
607 : /*
608 : * Reconnect was successful, move on to do the
609 : * first child.
610 : */
611 0 : if (!list_empty(&s->children)) {
612 0 : s = list_first_entry(&s->children,
613 : struct serio, child_node);
614 0 : 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 0 : while (s != root) {
624 0 : struct serio *parent = s->parent;
625 :
626 0 : if (!list_is_last(&s->child_node, &parent->children)) {
627 0 : s = list_entry(s->child_node.next,
628 : struct serio, child_node);
629 0 : break;
630 : }
631 :
632 : s = parent;
633 : }
634 0 : } while (s != root);
635 0 : }
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 : */
641 0 : static void serio_disconnect_port(struct serio *serio)
642 : {
643 0 : 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 0 : while (!list_empty(&serio->children)) {
650 :
651 : /* Locate a leaf */
652 0 : while (!list_empty(&s->children))
653 0 : 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 0 : if (s != serio) {
661 0 : struct serio *parent = s->parent;
662 :
663 0 : device_release_driver(&s->dev);
664 0 : serio_destroy_port(s);
665 :
666 0 : s = parent;
667 : }
668 : }
669 :
670 : /*
671 : * OK, no children left, now disconnect this port.
672 : */
673 0 : device_release_driver(&serio->dev);
674 0 : }
675 :
676 0 : void serio_rescan(struct serio *serio)
677 : {
678 0 : serio_queue_event(serio, NULL, SERIO_RESCAN_PORT);
679 0 : }
680 : EXPORT_SYMBOL(serio_rescan);
681 :
682 0 : void serio_reconnect(struct serio *serio)
683 : {
684 0 : serio_queue_event(serio, NULL, SERIO_RECONNECT_SUBTREE);
685 0 : }
686 : EXPORT_SYMBOL(serio_reconnect);
687 :
688 : /*
689 : * Submits register request to kseriod for subsequent execution.
690 : * Note that port registration is always asynchronous.
691 : */
692 0 : void __serio_register_port(struct serio *serio, struct module *owner)
693 : {
694 0 : serio_init_port(serio);
695 0 : serio_queue_event(serio, owner, SERIO_REGISTER_PORT);
696 0 : }
697 : EXPORT_SYMBOL(__serio_register_port);
698 :
699 : /*
700 : * Synchronously unregisters serio port.
701 : */
702 0 : void serio_unregister_port(struct serio *serio)
703 : {
704 0 : mutex_lock(&serio_mutex);
705 0 : serio_disconnect_port(serio);
706 0 : serio_destroy_port(serio);
707 0 : mutex_unlock(&serio_mutex);
708 0 : }
709 : EXPORT_SYMBOL(serio_unregister_port);
710 :
711 : /*
712 : * Safely unregisters children ports if they are present.
713 : */
714 0 : void serio_unregister_child_port(struct serio *serio)
715 : {
716 : struct serio *s, *next;
717 :
718 0 : mutex_lock(&serio_mutex);
719 0 : list_for_each_entry_safe(s, next, &serio->children, child_node) {
720 0 : serio_disconnect_port(s);
721 0 : serio_destroy_port(s);
722 : }
723 0 : mutex_unlock(&serio_mutex);
724 0 : }
725 : EXPORT_SYMBOL(serio_unregister_child_port);
726 :
727 :
728 : /*
729 : * Serio driver operations
730 : */
731 :
732 0 : static ssize_t description_show(struct device_driver *drv, char *buf)
733 : {
734 0 : struct serio_driver *driver = to_serio_driver(drv);
735 0 : return sprintf(buf, "%s\n", driver->description ? driver->description : "(none)");
736 : }
737 : static DRIVER_ATTR_RO(description);
738 :
739 0 : static ssize_t bind_mode_show(struct device_driver *drv, char *buf)
740 : {
741 0 : struct serio_driver *serio_drv = to_serio_driver(drv);
742 0 : return sprintf(buf, "%s\n", serio_drv->manual_bind ? "manual" : "auto");
743 : }
744 :
745 0 : static ssize_t bind_mode_store(struct device_driver *drv, const char *buf, size_t count)
746 : {
747 0 : struct serio_driver *serio_drv = to_serio_driver(drv);
748 : int retval;
749 :
750 0 : retval = count;
751 0 : if (!strncmp(buf, "manual", count)) {
752 0 : serio_drv->manual_bind = true;
753 0 : } else if (!strncmp(buf, "auto", count)) {
754 0 : serio_drv->manual_bind = false;
755 : } else {
756 : retval = -EINVAL;
757 : }
758 :
759 0 : return retval;
760 : }
761 : static DRIVER_ATTR_RW(bind_mode);
762 :
763 : static struct attribute *serio_driver_attrs[] = {
764 : &driver_attr_description.attr,
765 : &driver_attr_bind_mode.attr,
766 : NULL,
767 : };
768 : ATTRIBUTE_GROUPS(serio_driver);
769 :
770 0 : static int serio_driver_probe(struct device *dev)
771 : {
772 0 : struct serio *serio = to_serio_port(dev);
773 0 : struct serio_driver *drv = to_serio_driver(dev->driver);
774 :
775 0 : return serio_connect_driver(serio, drv);
776 : }
777 :
778 0 : static void serio_driver_remove(struct device *dev)
779 : {
780 0 : struct serio *serio = to_serio_port(dev);
781 :
782 0 : serio_disconnect_driver(serio);
783 0 : }
784 :
785 0 : static void serio_cleanup(struct serio *serio)
786 : {
787 0 : mutex_lock(&serio->drv_mutex);
788 0 : if (serio->drv && serio->drv->cleanup)
789 0 : serio->drv->cleanup(serio);
790 0 : mutex_unlock(&serio->drv_mutex);
791 0 : }
792 :
793 0 : static void serio_shutdown(struct device *dev)
794 : {
795 0 : struct serio *serio = to_serio_port(dev);
796 :
797 0 : serio_cleanup(serio);
798 0 : }
799 :
800 2 : static void serio_attach_driver(struct serio_driver *drv)
801 : {
802 : int error;
803 :
804 2 : error = driver_attach(&drv->driver);
805 2 : if (error)
806 0 : pr_warn("driver_attach() failed for %s with error %d\n",
807 : drv->driver.name, error);
808 2 : }
809 :
810 2 : int __serio_register_driver(struct serio_driver *drv, struct module *owner, const char *mod_name)
811 : {
812 2 : bool manual_bind = drv->manual_bind;
813 : int error;
814 :
815 2 : drv->driver.bus = &serio_bus;
816 2 : drv->driver.owner = owner;
817 2 : 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 2 : drv->manual_bind = true;
824 :
825 2 : error = driver_register(&drv->driver);
826 2 : if (error) {
827 0 : pr_err("driver_register() failed for %s, error: %d\n",
828 : drv->driver.name, error);
829 0 : return error;
830 : }
831 :
832 : /*
833 : * Restore original bind mode and let kseriod bind the
834 : * driver to free ports
835 : */
836 2 : if (!manual_bind) {
837 2 : drv->manual_bind = false;
838 2 : error = serio_queue_event(drv, NULL, SERIO_ATTACH_DRIVER);
839 2 : if (error) {
840 0 : driver_unregister(&drv->driver);
841 0 : return error;
842 : }
843 : }
844 :
845 : return 0;
846 : }
847 : EXPORT_SYMBOL(__serio_register_driver);
848 :
849 0 : void serio_unregister_driver(struct serio_driver *drv)
850 : {
851 : struct serio *serio;
852 :
853 0 : mutex_lock(&serio_mutex);
854 :
855 0 : drv->manual_bind = true; /* so serio_find_driver ignores it */
856 0 : serio_remove_pending_events(drv);
857 :
858 : start_over:
859 0 : list_for_each_entry(serio, &serio_list, node) {
860 0 : if (serio->drv == drv) {
861 0 : serio_disconnect_port(serio);
862 0 : serio_find_driver(serio);
863 : /* we could've deleted some ports, restart */
864 0 : goto start_over;
865 : }
866 : }
867 :
868 0 : driver_unregister(&drv->driver);
869 0 : mutex_unlock(&serio_mutex);
870 0 : }
871 : EXPORT_SYMBOL(serio_unregister_driver);
872 :
873 : static void serio_set_drv(struct serio *serio, struct serio_driver *drv)
874 : {
875 0 : serio_pause_rx(serio);
876 0 : serio->drv = drv;
877 0 : serio_continue_rx(serio);
878 : }
879 :
880 0 : static int serio_bus_match(struct device *dev, struct device_driver *drv)
881 : {
882 0 : struct serio *serio = to_serio_port(dev);
883 0 : struct serio_driver *serio_drv = to_serio_driver(drv);
884 :
885 0 : if (serio->manual_bind || serio_drv->manual_bind)
886 : return 0;
887 :
888 0 : 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 :
898 0 : static int serio_uevent(const struct device *dev, struct kobj_uevent_env *env)
899 : {
900 : const struct serio *serio;
901 :
902 0 : if (!dev)
903 : return -ENODEV;
904 :
905 0 : serio = to_serio_port(dev);
906 :
907 0 : SERIO_ADD_UEVENT_VAR("SERIO_TYPE=%02x", serio->id.type);
908 0 : SERIO_ADD_UEVENT_VAR("SERIO_PROTO=%02x", serio->id.proto);
909 0 : SERIO_ADD_UEVENT_VAR("SERIO_ID=%02x", serio->id.id);
910 0 : SERIO_ADD_UEVENT_VAR("SERIO_EXTRA=%02x", serio->id.extra);
911 :
912 0 : 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 0 : if (serio->firmware_id[0])
916 0 : 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
924 0 : static int serio_suspend(struct device *dev)
925 : {
926 0 : struct serio *serio = to_serio_port(dev);
927 :
928 0 : serio_cleanup(serio);
929 :
930 0 : return 0;
931 : }
932 :
933 0 : static int serio_resume(struct device *dev)
934 : {
935 0 : struct serio *serio = to_serio_port(dev);
936 0 : int error = -ENOENT;
937 :
938 0 : mutex_lock(&serio->drv_mutex);
939 0 : if (serio->drv && serio->drv->fast_reconnect) {
940 0 : error = serio->drv->fast_reconnect(serio);
941 0 : if (error && error != -ENOENT)
942 0 : dev_warn(dev, "fast reconnect failed with error %d\n",
943 : error);
944 : }
945 0 : mutex_unlock(&serio->drv_mutex);
946 :
947 0 : if (error) {
948 : /*
949 : * Driver reconnect can take a while, so better let
950 : * kseriod deal with it.
951 : */
952 0 : serio_queue_event(serio, NULL, SERIO_RECONNECT_PORT);
953 : }
954 :
955 0 : return 0;
956 : }
957 :
958 : static 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 */
967 0 : int serio_open(struct serio *serio, struct serio_driver *drv)
968 : {
969 0 : serio_set_drv(serio, drv);
970 :
971 0 : if (serio->open && serio->open(serio)) {
972 0 : serio_set_drv(serio, NULL);
973 0 : return -1;
974 : }
975 : return 0;
976 : }
977 : EXPORT_SYMBOL(serio_open);
978 :
979 : /* called from serio_driver->connect/disconnect methods under serio_mutex */
980 0 : void serio_close(struct serio *serio)
981 : {
982 0 : if (serio->close)
983 0 : serio->close(serio);
984 :
985 0 : serio_set_drv(serio, NULL);
986 0 : }
987 : EXPORT_SYMBOL(serio_close);
988 :
989 0 : irqreturn_t serio_interrupt(struct serio *serio,
990 : unsigned char data, unsigned int dfl)
991 : {
992 : unsigned long flags;
993 0 : irqreturn_t ret = IRQ_NONE;
994 :
995 0 : spin_lock_irqsave(&serio->lock, flags);
996 :
997 0 : if (likely(serio->drv)) {
998 0 : ret = serio->drv->interrupt(serio, data, dfl);
999 0 : } else if (!dfl && device_is_registered(&serio->dev)) {
1000 0 : serio_rescan(serio);
1001 0 : ret = IRQ_HANDLED;
1002 : }
1003 :
1004 0 : spin_unlock_irqrestore(&serio->lock, flags);
1005 :
1006 0 : return ret;
1007 : }
1008 : EXPORT_SYMBOL(serio_interrupt);
1009 :
1010 : struct 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 : };
1022 : EXPORT_SYMBOL(serio_bus);
1023 :
1024 1 : static int __init serio_init(void)
1025 : {
1026 : int error;
1027 :
1028 1 : error = bus_register(&serio_bus);
1029 1 : if (error) {
1030 0 : pr_err("Failed to register serio bus, error: %d\n", error);
1031 0 : return error;
1032 : }
1033 :
1034 : return 0;
1035 : }
1036 :
1037 0 : static void __exit serio_exit(void)
1038 : {
1039 0 : 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 0 : cancel_work_sync(&serio_event_work);
1046 0 : }
1047 :
1048 : subsys_initcall(serio_init);
1049 : module_exit(serio_exit);
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