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);