drivers/input/serio/serio.c

   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 #include <linux/stddef.h>
  30 #include <linux/module.h>
  31 #include <linux/serio.h>
  32 #include <linux/errno.h>
  33 #include <linux/wait.h>
  34 #include <linux/sched.h>
  35 #include <linux/slab.h>
  36 #include <linux/kthread.h>
  37
  38 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
  39 MODULE_DESCRIPTION("Serio abstraction core");
  40 MODULE_LICENSE("GPL");
  41
  42 EXPORT_SYMBOL(serio_interrupt);
  43 EXPORT_SYMBOL(__serio_register_port);
  44 EXPORT_SYMBOL(serio_unregister_port);
  45 EXPORT_SYMBOL(serio_unregister_child_port);
  46 EXPORT_SYMBOL(__serio_unregister_port_delayed);
  47 EXPORT_SYMBOL(__serio_register_driver);
  48 EXPORT_SYMBOL(serio_unregister_driver);
  49 EXPORT_SYMBOL(serio_open);
  50 EXPORT_SYMBOL(serio_close);
  51 EXPORT_SYMBOL(serio_rescan);
  52 EXPORT_SYMBOL(serio_reconnect);
  53
  54 /*
  55  * serio_sem protects entire serio subsystem and is taken every time
  56  * serio port or driver registrered or unregistered.
  57  */
  58 static DECLARE_MUTEX(serio_sem);
  59
  60 static LIST_HEAD(serio_list);
  61
  62 static struct bus_type serio_bus = {
  63         .name = "serio",
  64 };
  65
  66 static void serio_add_port(struct serio *serio);
  67 static void serio_destroy_port(struct serio *serio);
  68 static void serio_reconnect_port(struct serio *serio);
  69 static void serio_disconnect_port(struct serio *serio);
  70
  71 static int serio_connect_driver(struct serio *serio, struct serio_driver *drv)
  72 {
  73         int retval;
  74
  75         down(&serio->drv_sem);
  76         retval = drv->connect(serio, drv);
  77         up(&serio->drv_sem);
  78
  79         return retval;
  80 }
  81
  82 static int serio_reconnect_driver(struct serio *serio)
  83 {
  84         int retval = -1;
  85
  86         down(&serio->drv_sem);
  87         if (serio->drv && serio->drv->reconnect)
  88                 retval = serio->drv->reconnect(serio);
  89         up(&serio->drv_sem);
  90
  91         return retval;
  92 }
  93
  94 static void serio_disconnect_driver(struct serio *serio)
  95 {
  96         down(&serio->drv_sem);
  97         if (serio->drv)
  98                 serio->drv->disconnect(serio);
  99         up(&serio->drv_sem);
 100 }
 101
 102 static int serio_match_port(const struct serio_device_id *ids, struct serio *serio)
 103 {
 104         while (ids->type || ids->proto) {
 105                 if ((ids->type == SERIO_ANY || ids->type == serio->id.type) &&
 106                     (ids->proto == SERIO_ANY || ids->proto == serio->id.proto) &&
 107                     (ids->extra == SERIO_ANY || ids->extra == serio->id.extra) &&
 108                     (ids->id == SERIO_ANY || ids->id == serio->id.id))
 109                         return 1;
 110                 ids++;
 111         }
 112         return 0;
 113 }
 114
 115 /*
 116  * Basic serio -> driver core mappings
 117  */
 118
 119 static void serio_bind_driver(struct serio *serio, struct serio_driver *drv)
 120 {
 121         down_write(&serio_bus.subsys.rwsem);
 122
 123         if (serio_match_port(drv->id_table, serio)) {
 124                 serio->dev.driver = &drv->driver;
 125                 if (serio_connect_driver(serio, drv)) {
 126                         serio->dev.driver = NULL;
 127                         goto out;
 128                 }
 129                 device_bind_driver(&serio->dev);
 130         }
 131 out:
 132         up_write(&serio_bus.subsys.rwsem);
 133 }
 134
 135 static void serio_release_driver(struct serio *serio)
 136 {
 137         down_write(&serio_bus.subsys.rwsem);
 138         device_release_driver(&serio->dev);
 139         up_write(&serio_bus.subsys.rwsem);
 140 }
 141
 142 static void serio_find_driver(struct serio *serio)
 143 {
 144         down_write(&serio_bus.subsys.rwsem);
 145         device_attach(&serio->dev);
 146         up_write(&serio_bus.subsys.rwsem);
 147 }
 148
 149
 150 /*
 151  * Serio event processing.
 152  */
 153
 154 enum serio_event_type {
 155         SERIO_RESCAN,
 156         SERIO_RECONNECT,
 157         SERIO_REGISTER_PORT,
 158         SERIO_UNREGISTER_PORT,
 159         SERIO_REGISTER_DRIVER,
 160 };
 161
 162 struct serio_event {
 163         enum serio_event_type type;
 164         void *object;
 165         struct module *owner;
 166         struct list_head node;
 167 };
 168
 169 static DEFINE_SPINLOCK(serio_event_lock);       /* protects serio_event_list */
 170 static LIST_HEAD(serio_event_list);
 171 static DECLARE_WAIT_QUEUE_HEAD(serio_wait);
 172 static struct task_struct *serio_task;
 173
 174 static void serio_queue_event(void *object, struct module *owner,
 175                               enum serio_event_type event_type)
 176 {
 177         unsigned long flags;
 178         struct serio_event *event;
 179
 180         spin_lock_irqsave(&serio_event_lock, flags);
 181
 182         /*
 183          * Scan event list for the other events for the same serio port,
 184          * starting with the most recent one. If event is the same we
 185          * do not need add new one. If event is of different type we
 186          * need to add this event and should not look further because
 187          * we need to preseve sequence of distinct events.
 188          */
 189         list_for_each_entry_reverse(event, &serio_event_list, node) {
 190                 if (event->object == object) {
 191                         if (event->type == event_type)
 192                                 goto out;
 193                         break;
 194                 }
 195         }
 196
 197         if ((event = kmalloc(sizeof(struct serio_event), GFP_ATOMIC))) {
 198                 if (!try_module_get(owner)) {
 199                         printk(KERN_WARNING "serio: Can't get module reference, dropping event %d\n", event_type);
 200                         goto out;
 201                 }
 202
 203                 event->type = event_type;
 204                 event->object = object;
 205                 event->owner = owner;
 206
 207                 list_add_tail(&event->node, &serio_event_list);
 208                 wake_up(&serio_wait);
 209         } else {
 210                 printk(KERN_ERR "serio: Not enough memory to queue event %d\n", event_type);
 211         }
 212 out:
 213         spin_unlock_irqrestore(&serio_event_lock, flags);
 214 }
 215
 216 static void serio_free_event(struct serio_event *event)
 217 {
 218         module_put(event->owner);
 219         kfree(event);
 220 }
 221
 222 static void serio_remove_duplicate_events(struct serio_event *event)
 223 {
 224         struct list_head *node, *next;
 225         struct serio_event *e;
 226         unsigned long flags;
 227
 228         spin_lock_irqsave(&serio_event_lock, flags);
 229
 230         list_for_each_safe(node, next, &serio_event_list) {
 231                 e = list_entry(node, struct serio_event, node);
 232                 if (event->object == e->object) {
 233                         /*
 234                          * If this event is of different type we should not
 235                          * look further - we only suppress duplicate events
 236                          * that were sent back-to-back.
 237                          */
 238                         if (event->type != e->type)
 239                                 break;
 240
 241                         list_del_init(node);
 242                         serio_free_event(e);
 243                 }
 244         }
 245
 246         spin_unlock_irqrestore(&serio_event_lock, flags);
 247 }
 248
 249
 250 static struct serio_event *serio_get_event(void)
 251 {
 252         struct serio_event *event;
 253         struct list_head *node;
 254         unsigned long flags;
 255
 256         spin_lock_irqsave(&serio_event_lock, flags);
 257
 258         if (list_empty(&serio_event_list)) {
 259                 spin_unlock_irqrestore(&serio_event_lock, flags);
 260                 return NULL;
 261         }
 262
 263         node = serio_event_list.next;
 264         event = list_entry(node, struct serio_event, node);
 265         list_del_init(node);
 266
 267         spin_unlock_irqrestore(&serio_event_lock, flags);
 268
 269         return event;
 270 }
 271
 272 static void serio_handle_event(void)
 273 {
 274         struct serio_event *event;
 275         struct serio_driver *serio_drv;
 276
 277         down(&serio_sem);
 278
 279         /*
 280          * Note that we handle only one event here to give swsusp
 281          * a chance to freeze kseriod thread. Serio events should
 282          * be pretty rare so we are not concerned about taking
 283          * performance hit.
 284          */
 285         if ((event = serio_get_event())) {
 286
 287                 switch (event->type) {
 288                         case SERIO_REGISTER_PORT:
 289                                 serio_add_port(event->object);
 290                                 break;
 291
 292                         case SERIO_UNREGISTER_PORT:
 293                                 serio_disconnect_port(event->object);
 294                                 serio_destroy_port(event->object);
 295                                 break;
 296
 297                         case SERIO_RECONNECT:
 298                                 serio_reconnect_port(event->object);
 299                                 break;
 300
 301                         case SERIO_RESCAN:
 302                                 serio_disconnect_port(event->object);
 303                                 serio_find_driver(event->object);
 304                                 break;
 305
 306                         case SERIO_REGISTER_DRIVER:
 307                                 serio_drv = event->object;
 308                                 driver_register(&serio_drv->driver);
 309                                 break;
 310
 311                         default:
 312                                 break;
 313                 }
 314
 315                 serio_remove_duplicate_events(event);
 316                 serio_free_event(event);
 317         }
 318
 319         up(&serio_sem);
 320 }
 321
 322 /*
 323  * Remove all events that have been submitted for a given serio port.
 324  */
 325 static void serio_remove_pending_events(struct serio *serio)
 326 {
 327         struct list_head *node, *next;
 328         struct serio_event *event;
 329         unsigned long flags;
 330
 331         spin_lock_irqsave(&serio_event_lock, flags);
 332
 333         list_for_each_safe(node, next, &serio_event_list) {
 334                 event = list_entry(node, struct serio_event, node);
 335                 if (event->object == serio) {
 336                         list_del_init(node);
 337                         serio_free_event(event);
 338                 }
 339         }
 340
 341         spin_unlock_irqrestore(&serio_event_lock, flags);
 342 }
 343
 344 /*
 345  * Destroy child serio port (if any) that has not been fully registered yet.
 346  *
 347  * Note that we rely on the fact that port can have only one child and therefore
 348  * only one child registration request can be pending. Additionally, children
 349  * are registered by driver's connect() handler so there can't be a grandchild
 350  * pending registration together with a child.
 351  */
 352 static struct serio *serio_get_pending_child(struct serio *parent)
 353 {
 354         struct serio_event *event;
 355         struct serio *serio, *child = NULL;
 356         unsigned long flags;
 357
 358         spin_lock_irqsave(&serio_event_lock, flags);
 359
 360         list_for_each_entry(event, &serio_event_list, node) {
 361                 if (event->type == SERIO_REGISTER_PORT) {
 362                         serio = event->object;
 363                         if (serio->parent == parent) {
 364                                 child = serio;
 365                                 break;
 366                         }
 367                 }
 368         }
 369
 370         spin_unlock_irqrestore(&serio_event_lock, flags);
 371         return child;
 372 }
 373
 374 static int serio_thread(void *nothing)
 375 {
 376         do {
 377                 serio_handle_event();
 378                 wait_event_interruptible(serio_wait,
 379                         kthread_should_stop() || !list_empty(&serio_event_list));
 380                 try_to_freeze();
 381         } while (!kthread_should_stop());
 382
 383         printk(KERN_DEBUG "serio: kseriod exiting\n");
 384         return 0;
 385 }
 386
 387
 388 /*
 389  * Serio port operations
 390  */
 391
 392 static ssize_t serio_show_description(struct device *dev, struct device_attribute *attr, char *buf)
 393 {
 394         struct serio *serio = to_serio_port(dev);
 395         return sprintf(buf, "%s\n", serio->name);
 396 }
 397
 398 static ssize_t serio_show_modalias(struct device *dev, struct device_attribute *attr, char *buf)
 399 {
 400         struct serio *serio = to_serio_port(dev);
 401
 402         return sprintf(buf, "serio:ty%02Xpr%02Xid%02Xex%02X\n",
 403                         serio->id.type, serio->id.proto, serio->id.id, serio->id.extra);
 404 }
 405
 406 static ssize_t serio_show_id_type(struct device *dev, struct device_attribute *attr, char *buf)
 407 {
 408         struct serio *serio = to_serio_port(dev);
 409         return sprintf(buf, "%02x\n", serio->id.type);
 410 }
 411
 412 static ssize_t serio_show_id_proto(struct device *dev, struct device_attribute *attr, char *buf)
 413 {
 414         struct serio *serio = to_serio_port(dev);
 415         return sprintf(buf, "%02x\n", serio->id.proto);
 416 }
 417
 418 static ssize_t serio_show_id_id(struct device *dev, struct device_attribute *attr, char *buf)
 419 {
 420         struct serio *serio = to_serio_port(dev);
 421         return sprintf(buf, "%02x\n", serio->id.id);
 422 }
 423
 424 static ssize_t serio_show_id_extra(struct device *dev, struct device_attribute *attr, char *buf)
 425 {
 426         struct serio *serio = to_serio_port(dev);
 427         return sprintf(buf, "%02x\n", serio->id.extra);
 428 }
 429
 430 static DEVICE_ATTR(type, S_IRUGO, serio_show_id_type, NULL);
 431 static DEVICE_ATTR(proto, S_IRUGO, serio_show_id_proto, NULL);
 432 static DEVICE_ATTR(id, S_IRUGO, serio_show_id_id, NULL);
 433 static DEVICE_ATTR(extra, S_IRUGO, serio_show_id_extra, NULL);
 434
 435 static struct attribute *serio_device_id_attrs[] = {
 436         &dev_attr_type.attr,
 437         &dev_attr_proto.attr,
 438         &dev_attr_id.attr,
 439         &dev_attr_extra.attr,
 440         NULL
 441 };
 442
 443 static struct attribute_group serio_id_attr_group = {
 444         .name   = "id",
 445         .attrs  = serio_device_id_attrs,
 446 };
 447
 448 static ssize_t serio_rebind_driver(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 449 {
 450         struct serio *serio = to_serio_port(dev);
 451         struct device_driver *drv;
 452         int retval;
 453
 454         retval = down_interruptible(&serio_sem);
 455         if (retval)
 456                 return retval;
 457
 458         retval = count;
 459         if (!strncmp(buf, "none", count)) {
 460                 serio_disconnect_port(serio);
 461         } else if (!strncmp(buf, "reconnect", count)) {
 462                 serio_reconnect_port(serio);
 463         } else if (!strncmp(buf, "rescan", count)) {
 464                 serio_disconnect_port(serio);
 465                 serio_find_driver(serio);
 466         } else if ((drv = driver_find(buf, &serio_bus)) != NULL) {
 467                 serio_disconnect_port(serio);
 468                 serio_bind_driver(serio, to_serio_driver(drv));
 469                 put_driver(drv);
 470         } else {
 471                 retval = -EINVAL;
 472         }
 473
 474         up(&serio_sem);
 475
 476         return retval;
 477 }
 478
 479 static ssize_t serio_show_bind_mode(struct device *dev, struct device_attribute *attr, char *buf)
 480 {
 481         struct serio *serio = to_serio_port(dev);
 482         return sprintf(buf, "%s\n", serio->manual_bind ? "manual" : "auto");
 483 }
 484
 485 static ssize_t serio_set_bind_mode(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 486 {
 487         struct serio *serio = to_serio_port(dev);
 488         int retval;
 489
 490         retval = count;
 491         if (!strncmp(buf, "manual", count)) {
 492                 serio->manual_bind = 1;
 493         } else if (!strncmp(buf, "auto", count)) {
 494                 serio->manual_bind = 0;
 495         } else {
 496                 retval = -EINVAL;
 497         }
 498
 499         return retval;
 500 }
 501
 502 static struct device_attribute serio_device_attrs[] = {
 503         __ATTR(description, S_IRUGO, serio_show_description, NULL),
 504         __ATTR(modalias, S_IRUGO, serio_show_modalias, NULL),
 505         __ATTR(drvctl, S_IWUSR, NULL, serio_rebind_driver),
 506         __ATTR(bind_mode, S_IWUSR | S_IRUGO, serio_show_bind_mode, serio_set_bind_mode),
 507         __ATTR_NULL
 508 };
 509
 510
 511 static void serio_release_port(struct device *dev)
 512 {
 513         struct serio *serio = to_serio_port(dev);
 514
 515         kfree(serio);
 516         module_put(THIS_MODULE);
 517 }
 518
 519 /*
 520  * Prepare serio port for registration.
 521  */
 522 static void serio_init_port(struct serio *serio)
 523 {
 524         static atomic_t serio_no = ATOMIC_INIT(0);
 525
 526         __module_get(THIS_MODULE);
 527
 528         spin_lock_init(&serio->lock);
 529         init_MUTEX(&serio->drv_sem);
 530         device_initialize(&serio->dev);
 531         snprintf(serio->dev.bus_id, sizeof(serio->dev.bus_id),
 532                  "serio%ld", (long)atomic_inc_return(&serio_no) - 1);
 533         serio->dev.bus = &serio_bus;
 534         serio->dev.release = serio_release_port;
 535         if (serio->parent)
 536                 serio->dev.parent = &serio->parent->dev;
 537 }
 538
 539 /*
 540  * Complete serio port registration.
 541  * Driver core will attempt to find appropriate driver for the port.
 542  */
 543 static void serio_add_port(struct serio *serio)
 544 {
 545         if (serio->parent) {
 546                 serio_pause_rx(serio->parent);
 547                 serio->parent->child = serio;
 548                 serio_continue_rx(serio->parent);
 549         }
 550
 551         list_add_tail(&serio->node, &serio_list);
 552         if (serio->start)
 553                 serio->start(serio);
 554         device_add(&serio->dev);
 555         sysfs_create_group(&serio->dev.kobj, &serio_id_attr_group);
 556         serio->registered = 1;
 557 }
 558
 559 /*
 560  * serio_destroy_port() completes deregistration process and removes
 561  * port from the system
 562  */
 563 static void serio_destroy_port(struct serio *serio)
 564 {
 565         struct serio *child;
 566
 567         child = serio_get_pending_child(serio);
 568         if (child) {
 569                 serio_remove_pending_events(child);
 570                 put_device(&child->dev);
 571         }
 572
 573         if (serio->stop)
 574                 serio->stop(serio);
 575
 576         if (serio->parent) {
 577                 serio_pause_rx(serio->parent);
 578                 serio->parent->child = NULL;
 579                 serio_continue_rx(serio->parent);
 580                 serio->parent = NULL;
 581         }
 582
 583         if (serio->registered) {
 584                 sysfs_remove_group(&serio->dev.kobj, &serio_id_attr_group);
 585                 device_del(&serio->dev);
 586                 list_del_init(&serio->node);
 587                 serio->registered = 0;
 588         }
 589
 590         serio_remove_pending_events(serio);
 591         put_device(&serio->dev);
 592 }
 593
 594 /*
 595  * Reconnect serio port and all its children (re-initialize attached devices)
 596  */
 597 static void serio_reconnect_port(struct serio *serio)
 598 {
 599         do {
 600                 if (serio_reconnect_driver(serio)) {
 601                         serio_disconnect_port(serio);
 602                         serio_find_driver(serio);
 603                         /* Ok, old children are now gone, we are done */
 604                         break;
 605                 }
 606                 serio = serio->child;
 607         } while (serio);
 608 }
 609
 610 /*
 611  * serio_disconnect_port() unbinds a port from its driver. As a side effect
 612  * all child ports are unbound and destroyed.
 613  */
 614 static void serio_disconnect_port(struct serio *serio)
 615 {
 616         struct serio *s, *parent;
 617
 618         if (serio->child) {
 619                 /*
 620                  * Children ports should be disconnected and destroyed
 621                  * first, staring with the leaf one, since we don't want
 622                  * to do recursion
 623                  */
 624                 for (s = serio; s->child; s = s->child)
 625                         /* empty */;
 626
 627                 do {
 628                         parent = s->parent;
 629
 630                         serio_release_driver(s);
 631                         serio_destroy_port(s);
 632                 } while ((s = parent) != serio);
 633         }
 634
 635         /*
 636          * Ok, no children left, now disconnect this port
 637          */
 638         serio_release_driver(serio);
 639 }
 640
 641 void serio_rescan(struct serio *serio)
 642 {
 643         serio_queue_event(serio, NULL, SERIO_RESCAN);
 644 }
 645
 646 void serio_reconnect(struct serio *serio)
 647 {
 648         serio_queue_event(serio, NULL, SERIO_RECONNECT);
 649 }
 650
 651 /*
 652  * Submits register request to kseriod for subsequent execution.
 653  * Note that port registration is always asynchronous.
 654  */
 655 void __serio_register_port(struct serio *serio, struct module *owner)
 656 {
 657         serio_init_port(serio);
 658         serio_queue_event(serio, owner, SERIO_REGISTER_PORT);
 659 }
 660
 661 /*
 662  * Synchronously unregisters serio port.
 663  */
 664 void serio_unregister_port(struct serio *serio)
 665 {
 666         down(&serio_sem);
 667         serio_disconnect_port(serio);
 668         serio_destroy_port(serio);
 669         up(&serio_sem);
 670 }
 671
 672 /*
 673  * Safely unregisters child port if one is present.
 674  */
 675 void serio_unregister_child_port(struct serio *serio)
 676 {
 677         down(&serio_sem);
 678         if (serio->child) {
 679                 serio_disconnect_port(serio->child);
 680                 serio_destroy_port(serio->child);
 681         }
 682         up(&serio_sem);
 683 }
 684
 685 /*
 686  * Submits register request to kseriod for subsequent execution.
 687  * Can be used when it is not obvious whether the serio_sem is
 688  * taken or not and when delayed execution is feasible.
 689  */
 690 void __serio_unregister_port_delayed(struct serio *serio, struct module *owner)
 691 {
 692         serio_queue_event(serio, owner, SERIO_UNREGISTER_PORT);
 693 }
 694
 695
 696 /*
 697  * Serio driver operations
 698  */
 699
 700 static ssize_t serio_driver_show_description(struct device_driver *drv, char *buf)
 701 {
 702         struct serio_driver *driver = to_serio_driver(drv);
 703         return sprintf(buf, "%s\n", driver->description ? driver->description : "(none)");
 704 }
 705
 706 static ssize_t serio_driver_show_bind_mode(struct device_driver *drv, char *buf)
 707 {
 708         struct serio_driver *serio_drv = to_serio_driver(drv);
 709         return sprintf(buf, "%s\n", serio_drv->manual_bind ? "manual" : "auto");
 710 }
 711
 712 static ssize_t serio_driver_set_bind_mode(struct device_driver *drv, const char *buf, size_t count)
 713 {
 714         struct serio_driver *serio_drv = to_serio_driver(drv);
 715         int retval;
 716
 717         retval = count;
 718         if (!strncmp(buf, "manual", count)) {
 719                 serio_drv->manual_bind = 1;
 720         } else if (!strncmp(buf, "auto", count)) {
 721                 serio_drv->manual_bind = 0;
 722         } else {
 723                 retval = -EINVAL;
 724         }
 725
 726         return retval;
 727 }
 728
 729
 730 static struct driver_attribute serio_driver_attrs[] = {
 731         __ATTR(description, S_IRUGO, serio_driver_show_description, NULL),
 732         __ATTR(bind_mode, S_IWUSR | S_IRUGO,
 733                 serio_driver_show_bind_mode, serio_driver_set_bind_mode),
 734         __ATTR_NULL
 735 };
 736
 737 static int serio_driver_probe(struct device *dev)
 738 {
 739         struct serio *serio = to_serio_port(dev);
 740         struct serio_driver *drv = to_serio_driver(dev->driver);
 741
 742         return serio_connect_driver(serio, drv);
 743 }
 744
 745 static int serio_driver_remove(struct device *dev)
 746 {
 747         struct serio *serio = to_serio_port(dev);
 748
 749         serio_disconnect_driver(serio);
 750         return 0;
 751 }
 752
 753 void __serio_register_driver(struct serio_driver *drv, struct module *owner)
 754 {
 755         drv->driver.bus = &serio_bus;
 756         drv->driver.probe = serio_driver_probe;
 757         drv->driver.remove = serio_driver_remove;
 758
 759         serio_queue_event(drv, owner, SERIO_REGISTER_DRIVER);
 760 }
 761
 762 void serio_unregister_driver(struct serio_driver *drv)
 763 {
 764         struct serio *serio;
 765
 766         down(&serio_sem);
 767         drv->manual_bind = 1;   /* so serio_find_driver ignores it */
 768
 769 start_over:
 770         list_for_each_entry(serio, &serio_list, node) {
 771                 if (serio->drv == drv) {
 772                         serio_disconnect_port(serio);
 773                         serio_find_driver(serio);
 774                         /* we could've deleted some ports, restart */
 775                         goto start_over;
 776                 }
 777         }
 778
 779         driver_unregister(&drv->driver);
 780         up(&serio_sem);
 781 }
 782
 783 static void serio_set_drv(struct serio *serio, struct serio_driver *drv)
 784 {
 785         serio_pause_rx(serio);
 786         serio->drv = drv;
 787         serio_continue_rx(serio);
 788 }
 789
 790 static int serio_bus_match(struct device *dev, struct device_driver *drv)
 791 {
 792         struct serio *serio = to_serio_port(dev);
 793         struct serio_driver *serio_drv = to_serio_driver(drv);
 794
 795         if (serio->manual_bind || serio_drv->manual_bind)
 796                 return 0;
 797
 798         return serio_match_port(serio_drv->id_table, serio);
 799 }
 800
 801 #ifdef CONFIG_HOTPLUG
 802
 803 #define SERIO_ADD_HOTPLUG_VAR(fmt, val...)                              \
 804         do {                                                            \
 805                 int err = add_hotplug_env_var(envp, num_envp, &i,       \
 806                                         buffer, buffer_size, &len,      \
 807                                         fmt, val);                      \
 808                 if (err)                                                \
 809                         return err;                                     \
 810         } while (0)
 811
 812 static int serio_hotplug(struct device *dev, char **envp, int num_envp, char *buffer, int buffer_size)
 813 {
 814         struct serio *serio;
 815         int i = 0;
 816         int len = 0;
 817
 818         if (!dev)
 819                 return -ENODEV;
 820
 821         serio = to_serio_port(dev);
 822
 823         SERIO_ADD_HOTPLUG_VAR("SERIO_TYPE=%02x", serio->id.type);
 824         SERIO_ADD_HOTPLUG_VAR("SERIO_PROTO=%02x", serio->id.proto);
 825         SERIO_ADD_HOTPLUG_VAR("SERIO_ID=%02x", serio->id.id);
 826         SERIO_ADD_HOTPLUG_VAR("SERIO_EXTRA=%02x", serio->id.extra);
 827         SERIO_ADD_HOTPLUG_VAR("MODALIAS=serio:ty%02Xpr%02Xid%02Xex%02X",
 828                                 serio->id.type, serio->id.proto, serio->id.id, serio->id.extra);
 829         envp[i] = NULL;
 830
 831         return 0;
 832 }
 833 #undef SERIO_ADD_HOTPLUG_VAR
 834
 835 #else
 836
 837 static int serio_hotplug(struct device *dev, char **envp, int num_envp, char *buffer, int buffer_size)
 838 {
 839         return -ENODEV;
 840 }
 841
 842 #endif /* CONFIG_HOTPLUG */
 843
 844 static int serio_resume(struct device *dev)
 845 {
 846         struct serio *serio = to_serio_port(dev);
 847
 848         if (serio_reconnect_driver(serio)) {
 849                 /*
 850                  * Driver re-probing can take a while, so better let kseriod
 851                  * deal with it.
 852                  */
 853                 serio_rescan(serio);
 854         }
 855
 856         return 0;
 857 }
 858
 859 /* called from serio_driver->connect/disconnect methods under serio_sem */
 860 int serio_open(struct serio *serio, struct serio_driver *drv)
 861 {
 862         serio_set_drv(serio, drv);
 863
 864         if (serio->open && serio->open(serio)) {
 865                 serio_set_drv(serio, NULL);
 866                 return -1;
 867         }
 868         return 0;
 869 }
 870
 871 /* called from serio_driver->connect/disconnect methods under serio_sem */
 872 void serio_close(struct serio *serio)
 873 {
 874         if (serio->close)
 875                 serio->close(serio);
 876
 877         serio_set_drv(serio, NULL);
 878 }
 879
 880 irqreturn_t serio_interrupt(struct serio *serio,
 881                 unsigned char data, unsigned int dfl, struct pt_regs *regs)
 882 {
 883         unsigned long flags;
 884         irqreturn_t ret = IRQ_NONE;
 885
 886         spin_lock_irqsave(&serio->lock, flags);
 887
 888         if (likely(serio->drv)) {
 889                 ret = serio->drv->interrupt(serio, data, dfl, regs);
 890         } else if (!dfl && serio->registered) {
 891                 serio_rescan(serio);
 892                 ret = IRQ_HANDLED;
 893         }
 894
 895         spin_unlock_irqrestore(&serio->lock, flags);
 896
 897         return ret;
 898 }
 899
 900 static int __init serio_init(void)
 901 {
 902         serio_task = kthread_run(serio_thread, NULL, "kseriod");
 903         if (IS_ERR(serio_task)) {
 904                 printk(KERN_ERR "serio: Failed to start kseriod\n");
 905                 return PTR_ERR(serio_task);
 906         }
 907
 908         serio_bus.dev_attrs = serio_device_attrs;
 909         serio_bus.drv_attrs = serio_driver_attrs;
 910         serio_bus.match = serio_bus_match;
 911         serio_bus.hotplug = serio_hotplug;
 912         serio_bus.resume = serio_resume;
 913         bus_register(&serio_bus);
 914
 915         return 0;
 916 }
 917
 918 static void __exit serio_exit(void)
 919 {
 920         bus_unregister(&serio_bus);
 921         kthread_stop(serio_task);
 922 }
 923
 924 module_init(serio_init);
 925 module_exit(serio_exit);