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 | static 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(lock: &serio->drv_mutex); |
46 | |
47 | return retval; |
48 | } |
49 | |
50 | static 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(lock: &serio->drv_mutex); |
58 | |
59 | return retval; |
60 | } |
61 | |
62 | static 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(lock: &serio->drv_mutex); |
68 | } |
69 | |
70 | static 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 | |
87 | static int serio_bind_driver(struct serio *serio, struct serio_driver *drv) |
88 | { |
89 | int error; |
90 | |
91 | if (serio_match_port(ids: 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(dev: &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 | |
113 | static void serio_find_driver(struct serio *serio) |
114 | { |
115 | int error; |
116 | |
117 | error = device_attach(dev: &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 | |
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 | static 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(head: &serio_event_list)) { |
155 | event = list_first_entry(&serio_event_list, |
156 | struct serio_event, node); |
157 | list_del_init(entry: &event->node); |
158 | } |
159 | |
160 | spin_unlock_irqrestore(lock: &serio_event_lock, flags); |
161 | return event; |
162 | } |
163 | |
164 | static void serio_free_event(struct serio_event *event) |
165 | { |
166 | module_put(module: event->owner); |
167 | kfree(objp: event); |
168 | } |
169 | |
170 | 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 | 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(entry: &e->node); |
189 | serio_free_event(event: e); |
190 | } |
191 | } |
192 | |
193 | spin_unlock_irqrestore(lock: &serio_event_lock, flags); |
194 | } |
195 | |
196 | static 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(serio: event->object); |
208 | break; |
209 | |
210 | case SERIO_RECONNECT_PORT: |
211 | serio_reconnect_port(serio: event->object); |
212 | break; |
213 | |
214 | case SERIO_RESCAN_PORT: |
215 | serio_disconnect_port(serio: event->object); |
216 | serio_find_driver(serio: event->object); |
217 | break; |
218 | |
219 | case SERIO_RECONNECT_SUBTREE: |
220 | serio_reconnect_subtree(serio: event->object); |
221 | break; |
222 | |
223 | case SERIO_ATTACH_DRIVER: |
224 | serio_attach_driver(drv: event->object); |
225 | break; |
226 | } |
227 | |
228 | serio_remove_duplicate_events(object: event->object, type: event->type); |
229 | serio_free_event(event); |
230 | } |
231 | |
232 | mutex_unlock(lock: &serio_mutex); |
233 | } |
234 | |
235 | static DECLARE_WORK(serio_event_work, serio_handle_event); |
236 | |
237 | 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 | 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(size: 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(module: owner)) { |
269 | pr_warn("Can't get module reference, dropping event %d\n" , |
270 | event_type); |
271 | kfree(objp: 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(new: &event->node, head: &serio_event_list); |
281 | queue_work(wq: system_long_wq, work: &serio_event_work); |
282 | |
283 | out: |
284 | spin_unlock_irqrestore(lock: &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 | */ |
292 | static 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(entry: &event->node); |
302 | serio_free_event(event); |
303 | } |
304 | } |
305 | |
306 | spin_unlock_irqrestore(lock: &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 | */ |
315 | static 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(lock: &serio_event_lock, flags); |
334 | return child; |
335 | } |
336 | |
337 | /* |
338 | * Serio port operations |
339 | */ |
340 | |
341 | static 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, fmt: "%s\n" , serio->name); |
345 | } |
346 | |
347 | static 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, fmt: "serio:ty%02Xpr%02Xid%02Xex%02X\n" , |
352 | serio->id.type, serio->id.proto, serio->id.id, serio->id.extra); |
353 | } |
354 | |
355 | static 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, fmt: "%02x\n" , serio->id.type); |
359 | } |
360 | |
361 | static 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, fmt: "%02x\n" , serio->id.proto); |
365 | } |
366 | |
367 | static 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, fmt: "%02x\n" , serio->id.id); |
371 | } |
372 | |
373 | static ssize_t (struct device *dev, struct device_attribute *attr, char *buf) |
374 | { |
375 | struct serio *serio = to_serio_port(dev); |
376 | return sprintf(buf, fmt: "%02x\n" , serio->id.extra); |
377 | } |
378 | |
379 | static 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(object: serio, type: SERIO_RESCAN_PORT); |
397 | } else if ((drv = driver_find(name: buf, bus: &serio_bus)) != NULL) { |
398 | serio_disconnect_port(serio); |
399 | error = serio_bind_driver(serio, to_serio_driver(drv)); |
400 | serio_remove_duplicate_events(object: serio, type: SERIO_RESCAN_PORT); |
401 | } else { |
402 | error = -EINVAL; |
403 | } |
404 | |
405 | mutex_unlock(lock: &serio_mutex); |
406 | |
407 | return error ? error : count; |
408 | } |
409 | |
410 | static 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, fmt: "%s\n" , serio->manual_bind ? "manual" : "auto" ); |
414 | } |
415 | |
416 | static 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 | |
433 | static 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, fmt: "%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 | static void serio_release_port(struct device *dev) |
484 | { |
485 | struct serio *serio = to_serio_port(dev); |
486 | |
487 | kfree(objp: serio); |
488 | module_put(THIS_MODULE); |
489 | } |
490 | |
491 | /* |
492 | * Prepare serio port for registration. |
493 | */ |
494 | static 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(list: &serio->node); |
501 | INIT_LIST_HEAD(list: &serio->child_node); |
502 | INIT_LIST_HEAD(list: &serio->children); |
503 | spin_lock_init(&serio->lock); |
504 | mutex_init(&serio->drv_mutex); |
505 | device_initialize(dev: &serio->dev); |
506 | dev_set_name(dev: &serio->dev, name: "serio%lu" , |
507 | (unsigned long)atomic_inc_return(v: &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 | */ |
523 | static 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(serio: parent); |
530 | list_add_tail(new: &serio->child_node, head: &parent->children); |
531 | serio_continue_rx(serio: parent); |
532 | } |
533 | |
534 | list_add_tail(new: &serio->node, head: &serio_list); |
535 | |
536 | if (serio->start) |
537 | serio->start(serio); |
538 | |
539 | error = device_add(dev: &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 | */ |
550 | static void serio_destroy_port(struct serio *serio) |
551 | { |
552 | struct serio *child; |
553 | |
554 | while ((child = serio_get_pending_child(parent: serio)) != NULL) { |
555 | serio_remove_pending_events(object: child); |
556 | put_device(dev: &child->dev); |
557 | } |
558 | |
559 | if (serio->stop) |
560 | serio->stop(serio); |
561 | |
562 | if (serio->parent) { |
563 | serio_pause_rx(serio: serio->parent); |
564 | list_del_init(entry: &serio->child_node); |
565 | serio_continue_rx(serio: serio->parent); |
566 | serio->parent = NULL; |
567 | } |
568 | |
569 | if (device_is_registered(dev: &serio->dev)) |
570 | device_del(dev: &serio->dev); |
571 | |
572 | list_del_init(entry: &serio->node); |
573 | serio_remove_pending_events(object: serio); |
574 | put_device(dev: &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 | */ |
583 | static 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 | */ |
599 | static void serio_reconnect_subtree(struct serio *root) |
600 | { |
601 | struct serio *s = root; |
602 | int error; |
603 | |
604 | do { |
605 | error = serio_reconnect_port(serio: s); |
606 | if (!error) { |
607 | /* |
608 | * Reconnect was successful, move on to do the |
609 | * first child. |
610 | */ |
611 | if (!list_empty(head: &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(list: &s->child_node, head: &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 | */ |
641 | static 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(head: &serio->children)) { |
650 | |
651 | /* Locate a leaf */ |
652 | while (!list_empty(head: &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(dev: &s->dev); |
664 | serio_destroy_port(serio: s); |
665 | |
666 | s = parent; |
667 | } |
668 | } |
669 | |
670 | /* |
671 | * OK, no children left, now disconnect this port. |
672 | */ |
673 | device_release_driver(dev: &serio->dev); |
674 | } |
675 | |
676 | void serio_rescan(struct serio *serio) |
677 | { |
678 | serio_queue_event(object: serio, NULL, event_type: SERIO_RESCAN_PORT); |
679 | } |
680 | EXPORT_SYMBOL(serio_rescan); |
681 | |
682 | void serio_reconnect(struct serio *serio) |
683 | { |
684 | serio_queue_event(object: serio, NULL, event_type: SERIO_RECONNECT_SUBTREE); |
685 | } |
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 | void __serio_register_port(struct serio *serio, struct module *owner) |
693 | { |
694 | serio_init_port(serio); |
695 | serio_queue_event(object: serio, owner, event_type: SERIO_REGISTER_PORT); |
696 | } |
697 | EXPORT_SYMBOL(__serio_register_port); |
698 | |
699 | /* |
700 | * Synchronously unregisters serio port. |
701 | */ |
702 | void 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(lock: &serio_mutex); |
708 | } |
709 | EXPORT_SYMBOL(serio_unregister_port); |
710 | |
711 | /* |
712 | * Safely unregisters children ports if they are present. |
713 | */ |
714 | void 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(serio: s); |
721 | serio_destroy_port(serio: s); |
722 | } |
723 | mutex_unlock(lock: &serio_mutex); |
724 | } |
725 | EXPORT_SYMBOL(serio_unregister_child_port); |
726 | |
727 | |
728 | /* |
729 | * Serio driver operations |
730 | */ |
731 | |
732 | static ssize_t description_show(struct device_driver *drv, char *buf) |
733 | { |
734 | struct serio_driver *driver = to_serio_driver(drv); |
735 | return sprintf(buf, fmt: "%s\n" , driver->description ? driver->description : "(none)" ); |
736 | } |
737 | static DRIVER_ATTR_RO(description); |
738 | |
739 | static 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, fmt: "%s\n" , serio_drv->manual_bind ? "manual" : "auto" ); |
743 | } |
744 | |
745 | static 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 | } |
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 | static 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 | |
778 | static void serio_driver_remove(struct device *dev) |
779 | { |
780 | struct serio *serio = to_serio_port(dev); |
781 | |
782 | serio_disconnect_driver(serio); |
783 | } |
784 | |
785 | static 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(lock: &serio->drv_mutex); |
791 | } |
792 | |
793 | static void serio_shutdown(struct device *dev) |
794 | { |
795 | struct serio *serio = to_serio_port(dev); |
796 | |
797 | serio_cleanup(serio); |
798 | } |
799 | |
800 | static void serio_attach_driver(struct serio_driver *drv) |
801 | { |
802 | int error; |
803 | |
804 | error = driver_attach(drv: &drv->driver); |
805 | if (error) |
806 | pr_warn("driver_attach() failed for %s with error %d\n" , |
807 | drv->driver.name, error); |
808 | } |
809 | |
810 | int __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: &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(object: drv, NULL, event_type: SERIO_ATTACH_DRIVER); |
839 | if (error) { |
840 | driver_unregister(drv: &drv->driver); |
841 | return error; |
842 | } |
843 | } |
844 | |
845 | return 0; |
846 | } |
847 | EXPORT_SYMBOL(__serio_register_driver); |
848 | |
849 | void 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(object: drv); |
857 | |
858 | start_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: &drv->driver); |
869 | mutex_unlock(lock: &serio_mutex); |
870 | } |
871 | EXPORT_SYMBOL(serio_unregister_driver); |
872 | |
873 | static 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 | |
880 | static 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(ids: 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 | static 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 |
924 | static 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 | |
933 | static 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(lock: &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(object: serio, NULL, event_type: SERIO_RECONNECT_PORT); |
953 | } |
954 | |
955 | 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 | int 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 | } |
977 | EXPORT_SYMBOL(serio_open); |
978 | |
979 | /* called from serio_driver->connect/disconnect methods under serio_mutex */ |
980 | void serio_close(struct serio *serio) |
981 | { |
982 | if (serio->close) |
983 | serio->close(serio); |
984 | |
985 | serio_set_drv(serio, NULL); |
986 | } |
987 | EXPORT_SYMBOL(serio_close); |
988 | |
989 | irqreturn_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(dev: &serio->dev)) { |
1000 | serio_rescan(serio); |
1001 | ret = IRQ_HANDLED; |
1002 | } |
1003 | |
1004 | spin_unlock_irqrestore(lock: &serio->lock, flags); |
1005 | |
1006 | 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 | static int __init serio_init(void) |
1025 | { |
1026 | int error; |
1027 | |
1028 | error = bus_register(bus: &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 | |
1037 | static void __exit serio_exit(void) |
1038 | { |
1039 | bus_unregister(bus: &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(work: &serio_event_work); |
1046 | } |
1047 | |
1048 | subsys_initcall(serio_init); |
1049 | module_exit(serio_exit); |
1050 | |