drivers/acpi/dock.c

   1 /*
   2  *  dock.c - ACPI dock station driver
   3  *
   4  *  Copyright (C) 2006 Kristen Carlson Accardi <kristen.c.accardi@intel.com>
   5  *
   6  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   7  *
   8  *  This program is free software; you can redistribute it and/or modify
   9  *  it under the terms of the GNU General Public License as published by
  10  *  the Free Software Foundation; either version 2 of the License, or (at
  11  *  your option) any later version.
  12  *
  13  *  This program is distributed in the hope that it will be useful, but
  14  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  *  General Public License for more details.
  17  *
  18  *  You should have received a copy of the GNU General Public License along
  19  *  with this program; if not, write to the Free Software Foundation, Inc.,
  20  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  21  *
  22  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  23  */
  24
  25 #include <linux/kernel.h>
  26 #include <linux/module.h>
  27 #include <linux/slab.h>
  28 #include <linux/init.h>
  29 #include <linux/types.h>
  30 #include <linux/notifier.h>
  31 #include <linux/platform_device.h>
  32 #include <linux/jiffies.h>
  33 #include <linux/stddef.h>
  34 #include <linux/acpi.h>
  35 #include <acpi/acpi_bus.h>
  36 #include <acpi/acpi_drivers.h>
  37
  38 #define PREFIX "ACPI: "
  39
  40 #define ACPI_DOCK_DRIVER_DESCRIPTION "ACPI Dock Station Driver"
  41
  42 ACPI_MODULE_NAME("dock");
  43 MODULE_AUTHOR("Kristen Carlson Accardi");
  44 MODULE_DESCRIPTION(ACPI_DOCK_DRIVER_DESCRIPTION);
  45 MODULE_LICENSE("GPL");
  46
  47 static bool immediate_undock = 1;
  48 module_param(immediate_undock, bool, 0644);
  49 MODULE_PARM_DESC(immediate_undock, "1 (default) will cause the driver to "
  50         "undock immediately when the undock button is pressed, 0 will cause"
  51         " the driver to wait for userspace to write the undock sysfs file "
  52         " before undocking");
  53
  54 static const struct acpi_device_id dock_device_ids[] = {
  55         {"LNXDOCK", 0},
  56         {"", 0},
  57 };
  58 MODULE_DEVICE_TABLE(acpi, dock_device_ids);
  59
  60 struct dock_station {
  61         acpi_handle handle;
  62         unsigned long last_dock_time;
  63         u32 flags;
  64         struct list_head dependent_devices;
  65
  66         struct list_head sibling;
  67         struct platform_device *dock_device;
  68 };
  69 static LIST_HEAD(dock_stations);
  70 static int dock_station_count;
  71 static DEFINE_MUTEX(hotplug_lock);
  72
  73 struct dock_dependent_device {
  74         struct list_head list;
  75         acpi_handle handle;
  76         const struct acpi_dock_ops *hp_ops;
  77         void *hp_context;
  78         unsigned int hp_refcount;
  79         void (*hp_release)(void *);
  80 };
  81
  82 #define DOCK_DOCKING    0x00000001
  83 #define DOCK_UNDOCKING  0x00000002
  84 #define DOCK_IS_DOCK    0x00000010
  85 #define DOCK_IS_ATA     0x00000020
  86 #define DOCK_IS_BAT     0x00000040
  87 #define DOCK_EVENT      3
  88 #define UNDOCK_EVENT    2
  89
  90 enum dock_callback_type {
  91         DOCK_CALL_HANDLER,
  92         DOCK_CALL_FIXUP,
  93         DOCK_CALL_UEVENT,
  94 };
  95
  96 /*****************************************************************************
  97  *                         Dock Dependent device functions                   *
  98  *****************************************************************************/
  99 /**
 100  * add_dock_dependent_device - associate a device with the dock station
 101  * @ds: The dock station
 102  * @handle: handle of the dependent device
 103  *
 104  * Add the dependent device to the dock's dependent device list.
 105  */
 106 static int __init
 107 add_dock_dependent_device(struct dock_station *ds, acpi_handle handle)
 108 {
 109         struct dock_dependent_device *dd;
 110
 111         dd = kzalloc(sizeof(*dd), GFP_KERNEL);
 112         if (!dd)
 113                 return -ENOMEM;
 114
 115         dd->handle = handle;
 116         INIT_LIST_HEAD(&dd->list);
 117         list_add_tail(&dd->list, &ds->dependent_devices);
 118
 119         return 0;
 120 }
 121
 122 static void remove_dock_dependent_devices(struct dock_station *ds)
 123 {
 124         struct dock_dependent_device *dd, *aux;
 125
 126         list_for_each_entry_safe(dd, aux, &ds->dependent_devices, list) {
 127                 list_del(&dd->list);
 128                 kfree(dd);
 129         }
 130 }
 131
 132 /**
 133  * dock_init_hotplug - Initialize a hotplug device on a docking station.
 134  * @dd: Dock-dependent device.
 135  * @ops: Dock operations to attach to the dependent device.
 136  * @context: Data to pass to the @ops callbacks and @release.
 137  * @init: Optional initialization routine to run after setting up context.
 138  * @release: Optional release routine to run on removal.
 139  */
 140 static int dock_init_hotplug(struct dock_dependent_device *dd,
 141                              const struct acpi_dock_ops *ops, void *context,
 142                              void (*init)(void *), void (*release)(void *))
 143 {
 144         int ret = 0;
 145
 146         mutex_lock(&hotplug_lock);
 147         if (WARN_ON(dd->hp_context)) {
 148                 ret = -EEXIST;
 149         } else {
 150                 dd->hp_refcount = 1;
 151                 dd->hp_ops = ops;
 152                 dd->hp_context = context;
 153                 dd->hp_release = release;
 154                 if (init)
 155                         init(context);
 156         }
 157         mutex_unlock(&hotplug_lock);
 158         return ret;
 159 }
 160
 161 /**
 162  * dock_release_hotplug - Decrement hotplug reference counter of dock device.
 163  * @dd: Dock-dependent device.
 164  *
 165  * Decrement the reference counter of @dd and if 0, detach its hotplug
 166  * operations from it, reset its context pointer and run the optional release
 167  * routine if present.
 168  */
 169 static void dock_release_hotplug(struct dock_dependent_device *dd)
 170 {
 171         mutex_lock(&hotplug_lock);
 172         if (dd->hp_context && !--dd->hp_refcount) {
 173                 void (*release)(void *) = dd->hp_release;
 174                 void *context = dd->hp_context;
 175
 176                 dd->hp_ops = NULL;
 177                 dd->hp_context = NULL;
 178                 dd->hp_release = NULL;
 179                 if (release)
 180                         release(context);
 181         }
 182         mutex_unlock(&hotplug_lock);
 183 }
 184
 185 static void dock_hotplug_event(struct dock_dependent_device *dd, u32 event,
 186                                enum dock_callback_type cb_type)
 187 {
 188         acpi_notify_handler cb = NULL;
 189         bool run = false;
 190
 191         mutex_lock(&hotplug_lock);
 192
 193         if (dd->hp_context) {
 194                 run = true;
 195                 dd->hp_refcount++;
 196                 if (dd->hp_ops) {
 197                         switch (cb_type) {
 198                         case DOCK_CALL_FIXUP:
 199                                 cb = dd->hp_ops->fixup;
 200                                 break;
 201                         case DOCK_CALL_UEVENT:
 202                                 cb = dd->hp_ops->uevent;
 203                                 break;
 204                         default:
 205                                 cb = dd->hp_ops->handler;
 206                         }
 207                 }
 208         }
 209
 210         mutex_unlock(&hotplug_lock);
 211
 212         if (!run)
 213                 return;
 214
 215         if (cb)
 216                 cb(dd->handle, event, dd->hp_context);
 217
 218         dock_release_hotplug(dd);
 219 }
 220
 221 /**
 222  * find_dock_dependent_device - get a device dependent on this dock
 223  * @ds: the dock station
 224  * @handle: the acpi_handle of the device we want
 225  *
 226  * iterate over the dependent device list for this dock.  If the
 227  * dependent device matches the handle, return.
 228  */
 229 static struct dock_dependent_device *
 230 find_dock_dependent_device(struct dock_station *ds, acpi_handle handle)
 231 {
 232         struct dock_dependent_device *dd;
 233
 234         list_for_each_entry(dd, &ds->dependent_devices, list)
 235                 if (handle == dd->handle)
 236                         return dd;
 237
 238         return NULL;
 239 }
 240
 241 /*****************************************************************************
 242  *                         Dock functions                                    *
 243  *****************************************************************************/
 244 static int __init is_battery(acpi_handle handle)
 245 {
 246         struct acpi_device_info *info;
 247         int ret = 1;
 248
 249         if (!ACPI_SUCCESS(acpi_get_object_info(handle, &info)))
 250                 return 0;
 251         if (!(info->valid & ACPI_VALID_HID))
 252                 ret = 0;
 253         else
 254                 ret = !strcmp("PNP0C0A", info->hardware_id.string);
 255
 256         kfree(info);
 257         return ret;
 258 }
 259
 260 /* Check whether ACPI object is an ejectable battery or disk bay */
 261 static bool __init is_ejectable_bay(acpi_handle handle)
 262 {
 263         if (acpi_has_method(handle, "_EJ0") && is_battery(handle))
 264                 return true;
 265
 266         return acpi_bay_match(handle);
 267 }
 268
 269 /**
 270  * is_dock_device - see if a device is on a dock station
 271  * @handle: acpi handle of the device
 272  *
 273  * If this device is either the dock station itself,
 274  * or is a device dependent on the dock station, then it
 275  * is a dock device
 276  */
 277 int is_dock_device(acpi_handle handle)
 278 {
 279         struct dock_station *dock_station;
 280
 281         if (!dock_station_count)
 282                 return 0;
 283
 284         if (acpi_dock_match(handle))
 285                 return 1;
 286
 287         list_for_each_entry(dock_station, &dock_stations, sibling)
 288                 if (find_dock_dependent_device(dock_station, handle))
 289                         return 1;
 290
 291         return 0;
 292 }
 293 EXPORT_SYMBOL_GPL(is_dock_device);
 294
 295 /**
 296  * dock_present - see if the dock station is present.
 297  * @ds: the dock station
 298  *
 299  * execute the _STA method.  note that present does not
 300  * imply that we are docked.
 301  */
 302 static int dock_present(struct dock_station *ds)
 303 {
 304         unsigned long long sta;
 305         acpi_status status;
 306
 307         if (ds) {
 308                 status = acpi_evaluate_integer(ds->handle, "_STA", NULL, &sta);
 309                 if (ACPI_SUCCESS(status) && sta)
 310                         return 1;
 311         }
 312         return 0;
 313 }
 314
 315 /**
 316  * dock_create_acpi_device - add new devices to acpi
 317  * @handle - handle of the device to add
 318  *
 319  *  This function will create a new acpi_device for the given
 320  *  handle if one does not exist already.  This should cause
 321  *  acpi to scan for drivers for the given devices, and call
 322  *  matching driver's add routine.
 323  */
 324 static void dock_create_acpi_device(acpi_handle handle)
 325 {
 326         struct acpi_device *device;
 327         int ret;
 328
 329         if (acpi_bus_get_device(handle, &device)) {
 330                 /*
 331                  * no device created for this object,
 332                  * so we should create one.
 333                  */
 334                 ret = acpi_bus_scan(handle);
 335                 if (ret)
 336                         pr_debug("error adding bus, %x\n", -ret);
 337         }
 338 }
 339
 340 /**
 341  * dock_remove_acpi_device - remove the acpi_device struct from acpi
 342  * @handle - the handle of the device to remove
 343  *
 344  *  Tell acpi to remove the acpi_device.  This should cause any loaded
 345  *  driver to have it's remove routine called.
 346  */
 347 static void dock_remove_acpi_device(acpi_handle handle)
 348 {
 349         struct acpi_device *device;
 350
 351         if (!acpi_bus_get_device(handle, &device))
 352                 acpi_bus_trim(device);
 353 }
 354
 355 /**
 356  * hot_remove_dock_devices - Remove dock station devices.
 357  * @ds: Dock station.
 358  */
 359 static void hot_remove_dock_devices(struct dock_station *ds)
 360 {
 361         struct dock_dependent_device *dd;
 362
 363         /*
 364          * Walk the list in reverse order so that devices that have been added
 365          * last are removed first (in case there are some indirect dependencies
 366          * between them).
 367          */
 368         list_for_each_entry_reverse(dd, &ds->dependent_devices, list)
 369                 dock_hotplug_event(dd, ACPI_NOTIFY_EJECT_REQUEST, false);
 370
 371         list_for_each_entry_reverse(dd, &ds->dependent_devices, list)
 372                 dock_remove_acpi_device(dd->handle);
 373 }
 374
 375 /**
 376  * hotplug_dock_devices - Insert devices on a dock station.
 377  * @ds: the dock station
 378  * @event: either bus check or device check request
 379  *
 380  * Some devices on the dock station need to have drivers called
 381  * to perform hotplug operations after a dock event has occurred.
 382  * Traverse the list of dock devices that have registered a
 383  * hotplug handler, and call the handler.
 384  */
 385 static void hotplug_dock_devices(struct dock_station *ds, u32 event)
 386 {
 387         struct dock_dependent_device *dd;
 388
 389         /* Call driver specific post-dock fixups. */
 390         list_for_each_entry(dd, &ds->dependent_devices, list)
 391                 dock_hotplug_event(dd, event, DOCK_CALL_FIXUP);
 392
 393         /* Call driver specific hotplug functions. */
 394         list_for_each_entry(dd, &ds->dependent_devices, list)
 395                 dock_hotplug_event(dd, event, DOCK_CALL_HANDLER);
 396
 397         /*
 398          * Now make sure that an acpi_device is created for each dependent
 399          * device.  That will cause scan handlers to be attached to device
 400          * objects or acpi_drivers to be stopped/started if they are present.
 401          */
 402         list_for_each_entry(dd, &ds->dependent_devices, list)
 403                 dock_create_acpi_device(dd->handle);
 404 }
 405
 406 static void dock_event(struct dock_station *ds, u32 event, int num)
 407 {
 408         struct device *dev = &ds->dock_device->dev;
 409         char event_string[13];
 410         char *envp[] = { event_string, NULL };
 411         struct dock_dependent_device *dd;
 412
 413         if (num == UNDOCK_EVENT)
 414                 sprintf(event_string, "EVENT=undock");
 415         else
 416                 sprintf(event_string, "EVENT=dock");
 417
 418         /*
 419          * Indicate that the status of the dock station has
 420          * changed.
 421          */
 422         if (num == DOCK_EVENT)
 423                 kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp);
 424
 425         list_for_each_entry(dd, &ds->dependent_devices, list)
 426                 dock_hotplug_event(dd, event, DOCK_CALL_UEVENT);
 427
 428         if (num != DOCK_EVENT)
 429                 kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp);
 430 }
 431
 432 /**
 433  * handle_dock - handle a dock event
 434  * @ds: the dock station
 435  * @dock: to dock, or undock - that is the question
 436  *
 437  * Execute the _DCK method in response to an acpi event
 438  */
 439 static void handle_dock(struct dock_station *ds, int dock)
 440 {
 441         acpi_status status;
 442         struct acpi_object_list arg_list;
 443         union acpi_object arg;
 444         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 445
 446         acpi_handle_info(ds->handle, "%s\n", dock ? "docking" : "undocking");
 447
 448         /* _DCK method has one argument */
 449         arg_list.count = 1;
 450         arg_list.pointer = &arg;
 451         arg.type = ACPI_TYPE_INTEGER;
 452         arg.integer.value = dock;
 453         status = acpi_evaluate_object(ds->handle, "_DCK", &arg_list, &buffer);
 454         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND)
 455                 acpi_handle_err(ds->handle, "Failed to execute _DCK (0x%x)\n",
 456                                 status);
 457
 458         kfree(buffer.pointer);
 459 }
 460
 461 static inline void dock(struct dock_station *ds)
 462 {
 463         handle_dock(ds, 1);
 464 }
 465
 466 static inline void undock(struct dock_station *ds)
 467 {
 468         handle_dock(ds, 0);
 469 }
 470
 471 static inline void begin_dock(struct dock_station *ds)
 472 {
 473         ds->flags |= DOCK_DOCKING;
 474 }
 475
 476 static inline void complete_dock(struct dock_station *ds)
 477 {
 478         ds->flags &= ~(DOCK_DOCKING);
 479         ds->last_dock_time = jiffies;
 480 }
 481
 482 static inline void begin_undock(struct dock_station *ds)
 483 {
 484         ds->flags |= DOCK_UNDOCKING;
 485 }
 486
 487 static inline void complete_undock(struct dock_station *ds)
 488 {
 489         ds->flags &= ~(DOCK_UNDOCKING);
 490 }
 491
 492 /**
 493  * dock_in_progress - see if we are in the middle of handling a dock event
 494  * @ds: the dock station
 495  *
 496  * Sometimes while docking, false dock events can be sent to the driver
 497  * because good connections aren't made or some other reason.  Ignore these
 498  * if we are in the middle of doing something.
 499  */
 500 static int dock_in_progress(struct dock_station *ds)
 501 {
 502         if ((ds->flags & DOCK_DOCKING) ||
 503             time_before(jiffies, (ds->last_dock_time + HZ)))
 504                 return 1;
 505         return 0;
 506 }
 507
 508 /**
 509  * register_hotplug_dock_device - register a hotplug function
 510  * @handle: the handle of the device
 511  * @ops: handlers to call after docking
 512  * @context: device specific data
 513  * @init: Optional initialization routine to run after registration
 514  * @release: Optional release routine to run on unregistration
 515  *
 516  * If a driver would like to perform a hotplug operation after a dock
 517  * event, they can register an acpi_notifiy_handler to be called by
 518  * the dock driver after _DCK is executed.
 519  */
 520 int register_hotplug_dock_device(acpi_handle handle,
 521                                  const struct acpi_dock_ops *ops, void *context,
 522                                  void (*init)(void *), void (*release)(void *))
 523 {
 524         struct dock_dependent_device *dd;
 525         struct dock_station *dock_station;
 526         int ret = -EINVAL;
 527
 528         if (WARN_ON(!context))
 529                 return -EINVAL;
 530
 531         if (!dock_station_count)
 532                 return -ENODEV;
 533
 534         /*
 535          * make sure this handle is for a device dependent on the dock,
 536          * this would include the dock station itself
 537          */
 538         list_for_each_entry(dock_station, &dock_stations, sibling) {
 539                 /*
 540                  * An ATA bay can be in a dock and itself can be ejected
 541                  * separately, so there are two 'dock stations' which need the
 542                  * ops
 543                  */
 544                 dd = find_dock_dependent_device(dock_station, handle);
 545                 if (dd && !dock_init_hotplug(dd, ops, context, init, release))
 546                         ret = 0;
 547         }
 548
 549         return ret;
 550 }
 551 EXPORT_SYMBOL_GPL(register_hotplug_dock_device);
 552
 553 /**
 554  * unregister_hotplug_dock_device - remove yourself from the hotplug list
 555  * @handle: the acpi handle of the device
 556  */
 557 void unregister_hotplug_dock_device(acpi_handle handle)
 558 {
 559         struct dock_dependent_device *dd;
 560         struct dock_station *dock_station;
 561
 562         if (!dock_station_count)
 563                 return;
 564
 565         list_for_each_entry(dock_station, &dock_stations, sibling) {
 566                 dd = find_dock_dependent_device(dock_station, handle);
 567                 if (dd)
 568                         dock_release_hotplug(dd);
 569         }
 570 }
 571 EXPORT_SYMBOL_GPL(unregister_hotplug_dock_device);
 572
 573 /**
 574  * handle_eject_request - handle an undock request checking for error conditions
 575  *
 576  * Check to make sure the dock device is still present, then undock and
 577  * hotremove all the devices that may need removing.
 578  */
 579 static int handle_eject_request(struct dock_station *ds, u32 event)
 580 {
 581         if (dock_in_progress(ds))
 582                 return -EBUSY;
 583
 584         /*
 585          * here we need to generate the undock
 586          * event prior to actually doing the undock
 587          * so that the device struct still exists.
 588          * Also, even send the dock event if the
 589          * device is not present anymore
 590          */
 591         dock_event(ds, event, UNDOCK_EVENT);
 592
 593         hot_remove_dock_devices(ds);
 594         undock(ds);
 595         acpi_evaluate_lck(ds->handle, 0);
 596         acpi_evaluate_ej0(ds->handle);
 597         if (dock_present(ds)) {
 598                 acpi_handle_err(ds->handle, "Unable to undock!\n");
 599                 return -EBUSY;
 600         }
 601         complete_undock(ds);
 602         return 0;
 603 }
 604
 605 /**
 606  * dock_notify - act upon an acpi dock notification
 607  * @ds: dock station
 608  * @event: the acpi event
 609  *
 610  * If we are notified to dock, then check to see if the dock is
 611  * present and then dock.  Notify all drivers of the dock event,
 612  * and then hotplug and devices that may need hotplugging.
 613  */
 614 static void dock_notify(struct dock_station *ds, u32 event)
 615 {
 616         acpi_handle handle = ds->handle;
 617         struct acpi_device *ad;
 618         int surprise_removal = 0;
 619
 620         /*
 621          * According to acpi spec 3.0a, if a DEVICE_CHECK notification
 622          * is sent and _DCK is present, it is assumed to mean an undock
 623          * request.
 624          */
 625         if ((ds->flags & DOCK_IS_DOCK) && event == ACPI_NOTIFY_DEVICE_CHECK)
 626                 event = ACPI_NOTIFY_EJECT_REQUEST;
 627
 628         /*
 629          * dock station: BUS_CHECK - docked or surprise removal
 630          *               DEVICE_CHECK - undocked
 631          * other device: BUS_CHECK/DEVICE_CHECK - added or surprise removal
 632          *
 633          * To simplify event handling, dock dependent device handler always
 634          * get ACPI_NOTIFY_BUS_CHECK/ACPI_NOTIFY_DEVICE_CHECK for add and
 635          * ACPI_NOTIFY_EJECT_REQUEST for removal
 636          */
 637         switch (event) {
 638         case ACPI_NOTIFY_BUS_CHECK:
 639         case ACPI_NOTIFY_DEVICE_CHECK:
 640                 if (!dock_in_progress(ds) && acpi_bus_get_device(handle, &ad)) {
 641                         begin_dock(ds);
 642                         dock(ds);
 643                         if (!dock_present(ds)) {
 644                                 acpi_handle_err(handle, "Unable to dock!\n");
 645                                 complete_dock(ds);
 646                                 break;
 647                         }
 648                         hotplug_dock_devices(ds, event);
 649                         complete_dock(ds);
 650                         dock_event(ds, event, DOCK_EVENT);
 651                         acpi_evaluate_lck(ds->handle, 1);
 652                         acpi_update_all_gpes();
 653                         break;
 654                 }
 655                 if (dock_present(ds) || dock_in_progress(ds))
 656                         break;
 657                 /* This is a surprise removal */
 658                 surprise_removal = 1;
 659                 event = ACPI_NOTIFY_EJECT_REQUEST;
 660                 /* Fall back */
 661         case ACPI_NOTIFY_EJECT_REQUEST:
 662                 begin_undock(ds);
 663                 if ((immediate_undock && !(ds->flags & DOCK_IS_ATA))
 664                    || surprise_removal)
 665                         handle_eject_request(ds, event);
 666                 else
 667                         dock_event(ds, event, UNDOCK_EVENT);
 668                 break;
 669         default:
 670                 acpi_handle_err(handle, "Unknown dock event %d\n", event);
 671         }
 672 }
 673
 674 struct dock_data {
 675         struct dock_station *ds;
 676         u32 event;
 677 };
 678
 679 static void acpi_dock_deferred_cb(void *context)
 680 {
 681         struct dock_data *data = context;
 682
 683         acpi_scan_lock_acquire();
 684         dock_notify(data->ds, data->event);
 685         acpi_scan_lock_release();
 686         kfree(data);
 687 }
 688
 689 static void dock_notify_handler(acpi_handle handle, u32 event, void *data)
 690 {
 691         struct dock_data *dd;
 692
 693         if (event != ACPI_NOTIFY_BUS_CHECK && event != ACPI_NOTIFY_DEVICE_CHECK
 694            && event != ACPI_NOTIFY_EJECT_REQUEST)
 695                 return;
 696
 697         dd = kmalloc(sizeof(*dd), GFP_KERNEL);
 698         if (dd) {
 699                 acpi_status status;
 700
 701                 dd->ds = data;
 702                 dd->event = event;
 703                 status = acpi_os_hotplug_execute(acpi_dock_deferred_cb, dd);
 704                 if (ACPI_FAILURE(status))
 705                         kfree(dd);
 706         }
 707 }
 708
 709 /**
 710  * find_dock_devices - find devices on the dock station
 711  * @handle: the handle of the device we are examining
 712  * @lvl: unused
 713  * @context: the dock station private data
 714  * @rv: unused
 715  *
 716  * This function is called by acpi_walk_namespace.  It will
 717  * check to see if an object has an _EJD method.  If it does, then it
 718  * will see if it is dependent on the dock station.
 719  */
 720 static acpi_status __init find_dock_devices(acpi_handle handle, u32 lvl,
 721                                             void *context, void **rv)
 722 {
 723         struct dock_station *ds = context;
 724         acpi_handle ejd = NULL;
 725
 726         acpi_bus_get_ejd(handle, &ejd);
 727         if (ejd == ds->handle)
 728                 add_dock_dependent_device(ds, handle);
 729
 730         return AE_OK;
 731 }
 732
 733 /*
 734  * show_docked - read method for "docked" file in sysfs
 735  */
 736 static ssize_t show_docked(struct device *dev,
 737                            struct device_attribute *attr, char *buf)
 738 {
 739         struct acpi_device *tmp;
 740
 741         struct dock_station *dock_station = dev->platform_data;
 742
 743         if (!acpi_bus_get_device(dock_station->handle, &tmp))
 744                 return snprintf(buf, PAGE_SIZE, "1\n");
 745         return snprintf(buf, PAGE_SIZE, "0\n");
 746 }
 747 static DEVICE_ATTR(docked, S_IRUGO, show_docked, NULL);
 748
 749 /*
 750  * show_flags - read method for flags file in sysfs
 751  */
 752 static ssize_t show_flags(struct device *dev,
 753                           struct device_attribute *attr, char *buf)
 754 {
 755         struct dock_station *dock_station = dev->platform_data;
 756         return snprintf(buf, PAGE_SIZE, "%d\n", dock_station->flags);
 757
 758 }
 759 static DEVICE_ATTR(flags, S_IRUGO, show_flags, NULL);
 760
 761 /*
 762  * write_undock - write method for "undock" file in sysfs
 763  */
 764 static ssize_t write_undock(struct device *dev, struct device_attribute *attr,
 765                            const char *buf, size_t count)
 766 {
 767         int ret;
 768         struct dock_station *dock_station = dev->platform_data;
 769
 770         if (!count)
 771                 return -EINVAL;
 772
 773         acpi_scan_lock_acquire();
 774         begin_undock(dock_station);
 775         ret = handle_eject_request(dock_station, ACPI_NOTIFY_EJECT_REQUEST);
 776         acpi_scan_lock_release();
 777         return ret ? ret: count;
 778 }
 779 static DEVICE_ATTR(undock, S_IWUSR, NULL, write_undock);
 780
 781 /*
 782  * show_dock_uid - read method for "uid" file in sysfs
 783  */
 784 static ssize_t show_dock_uid(struct device *dev,
 785                              struct device_attribute *attr, char *buf)
 786 {
 787         unsigned long long lbuf;
 788         struct dock_station *dock_station = dev->platform_data;
 789         acpi_status status = acpi_evaluate_integer(dock_station->handle,
 790                                         "_UID", NULL, &lbuf);
 791         if (ACPI_FAILURE(status))
 792             return 0;
 793
 794         return snprintf(buf, PAGE_SIZE, "%llx\n", lbuf);
 795 }
 796 static DEVICE_ATTR(uid, S_IRUGO, show_dock_uid, NULL);
 797
 798 static ssize_t show_dock_type(struct device *dev,
 799                 struct device_attribute *attr, char *buf)
 800 {
 801         struct dock_station *dock_station = dev->platform_data;
 802         char *type;
 803
 804         if (dock_station->flags & DOCK_IS_DOCK)
 805                 type = "dock_station";
 806         else if (dock_station->flags & DOCK_IS_ATA)
 807                 type = "ata_bay";
 808         else if (dock_station->flags & DOCK_IS_BAT)
 809                 type = "battery_bay";
 810         else
 811                 type = "unknown";
 812
 813         return snprintf(buf, PAGE_SIZE, "%s\n", type);
 814 }
 815 static DEVICE_ATTR(type, S_IRUGO, show_dock_type, NULL);
 816
 817 static struct attribute *dock_attributes[] = {
 818         &dev_attr_docked.attr,
 819         &dev_attr_flags.attr,
 820         &dev_attr_undock.attr,
 821         &dev_attr_uid.attr,
 822         &dev_attr_type.attr,
 823         NULL
 824 };
 825
 826 static struct attribute_group dock_attribute_group = {
 827         .attrs = dock_attributes
 828 };
 829
 830 /**
 831  * dock_add - add a new dock station
 832  * @handle: the dock station handle
 833  *
 834  * allocated and initialize a new dock station device.  Find all devices
 835  * that are on the dock station, and register for dock event notifications.
 836  */
 837 static int __init dock_add(acpi_handle handle)
 838 {
 839         struct dock_station *dock_station, ds = { NULL, };
 840         struct platform_device *dd;
 841         acpi_status status;
 842         int ret;
 843
 844         dd = platform_device_register_data(NULL, "dock", dock_station_count,
 845                                            &ds, sizeof(ds));
 846         if (IS_ERR(dd))
 847                 return PTR_ERR(dd);
 848
 849         dock_station = dd->dev.platform_data;
 850
 851         dock_station->handle = handle;
 852         dock_station->dock_device = dd;
 853         dock_station->last_dock_time = jiffies - HZ;
 854
 855         INIT_LIST_HEAD(&dock_station->sibling);
 856         INIT_LIST_HEAD(&dock_station->dependent_devices);
 857
 858         /* we want the dock device to send uevents */
 859         dev_set_uevent_suppress(&dd->dev, 0);
 860
 861         if (acpi_dock_match(handle))
 862                 dock_station->flags |= DOCK_IS_DOCK;
 863         if (acpi_ata_match(handle))
 864                 dock_station->flags |= DOCK_IS_ATA;
 865         if (is_battery(handle))
 866                 dock_station->flags |= DOCK_IS_BAT;
 867
 868         ret = sysfs_create_group(&dd->dev.kobj, &dock_attribute_group);
 869         if (ret)
 870                 goto err_unregister;
 871
 872         /* Find dependent devices */
 873         acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 874                             ACPI_UINT32_MAX, find_dock_devices, NULL,
 875                             dock_station, NULL);
 876
 877         /* add the dock station as a device dependent on itself */
 878         ret = add_dock_dependent_device(dock_station, handle);
 879         if (ret)
 880                 goto err_rmgroup;
 881
 882         status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
 883                                              dock_notify_handler, dock_station);
 884         if (ACPI_FAILURE(status)) {
 885                 ret = -ENODEV;
 886                 goto err_rmgroup;
 887         }
 888
 889         dock_station_count++;
 890         list_add(&dock_station->sibling, &dock_stations);
 891         return 0;
 892
 893 err_rmgroup:
 894         remove_dock_dependent_devices(dock_station);
 895         sysfs_remove_group(&dd->dev.kobj, &dock_attribute_group);
 896 err_unregister:
 897         platform_device_unregister(dd);
 898         acpi_handle_err(handle, "%s encountered error %d\n", __func__, ret);
 899         return ret;
 900 }
 901
 902 /**
 903  * find_dock_and_bay - look for dock stations and bays
 904  * @handle: acpi handle of a device
 905  * @lvl: unused
 906  * @context: unused
 907  * @rv: unused
 908  *
 909  * This is called by acpi_walk_namespace to look for dock stations and bays.
 910  */
 911 static acpi_status __init
 912 find_dock_and_bay(acpi_handle handle, u32 lvl, void *context, void **rv)
 913 {
 914         if (acpi_dock_match(handle) || is_ejectable_bay(handle))
 915                 dock_add(handle);
 916
 917         return AE_OK;
 918 }
 919
 920 void __init acpi_dock_init(void)
 921 {
 922         if (acpi_disabled)
 923                 return;
 924
 925         /* look for dock stations and bays */
 926         acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 927                 ACPI_UINT32_MAX, find_dock_and_bay, NULL, NULL, NULL);
 928
 929         if (!dock_station_count) {
 930                 pr_info(PREFIX "No dock devices found.\n");
 931                 return;
 932         }
 933
 934         pr_info(PREFIX "%s: %d docks/bays found\n",
 935                 ACPI_DOCK_DRIVER_DESCRIPTION, dock_station_count);
 936 }