linux/drivers/acpi/dock.c
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   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
  42ACPI_MODULE_NAME("dock");
  43MODULE_AUTHOR("Kristen Carlson Accardi");
  44MODULE_DESCRIPTION(ACPI_DOCK_DRIVER_DESCRIPTION);
  45MODULE_LICENSE("GPL");
  46
  47static bool immediate_undock = 1;
  48module_param(immediate_undock, bool, 0644);
  49MODULE_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
  54static const struct acpi_device_id dock_device_ids[] = {
  55        {"LNXDOCK", 0},
  56        {"", 0},
  57};
  58MODULE_DEVICE_TABLE(acpi, dock_device_ids);
  59
  60struct 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};
  69static LIST_HEAD(dock_stations);
  70static int dock_station_count;
  71static DEFINE_MUTEX(hotplug_lock);
  72
  73struct 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
  90enum 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 */
 106static int __init
 107add_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
 122static 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 */
 140static 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 */
 169static 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
 185static 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 */
 229static struct dock_dependent_device *
 230find_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 *****************************************************************************/
 244static 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 */
 261static 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 */
 277int 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}
 293EXPORT_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 */
 302static 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 */
 324static 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 */
 347static 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 */
 359static 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 */
 385static 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
 406static 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 */
 439static 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
 461static inline void dock(struct dock_station *ds)
 462{
 463        handle_dock(ds, 1);
 464}
 465
 466static inline void undock(struct dock_station *ds)
 467{
 468        handle_dock(ds, 0);
 469}
 470
 471static inline void begin_dock(struct dock_station *ds)
 472{
 473        ds->flags |= DOCK_DOCKING;
 474}
 475
 476static inline void complete_dock(struct dock_station *ds)
 477{
 478        ds->flags &= ~(DOCK_DOCKING);
 479        ds->last_dock_time = jiffies;
 480}
 481
 482static inline void begin_undock(struct dock_station *ds)
 483{
 484        ds->flags |= DOCK_UNDOCKING;
 485}
 486
 487static 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 */
 500static 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 */
 520int 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}
 551EXPORT_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 */
 557void 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}
 571EXPORT_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 */
 579static 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 */
 614static 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
 674struct dock_data {
 675        struct dock_station *ds;
 676        u32 event;
 677};
 678
 679static 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
 689static 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 */
 720static 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 */
 736static 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}
 747static DEVICE_ATTR(docked, S_IRUGO, show_docked, NULL);
 748
 749/*
 750 * show_flags - read method for flags file in sysfs
 751 */
 752static 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}
 759static DEVICE_ATTR(flags, S_IRUGO, show_flags, NULL);
 760
 761/*
 762 * write_undock - write method for "undock" file in sysfs
 763 */
 764static 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}
 779static DEVICE_ATTR(undock, S_IWUSR, NULL, write_undock);
 780
 781/*
 782 * show_dock_uid - read method for "uid" file in sysfs
 783 */
 784static 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}
 796static DEVICE_ATTR(uid, S_IRUGO, show_dock_uid, NULL);
 797
 798static 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}
 815static DEVICE_ATTR(type, S_IRUGO, show_dock_type, NULL);
 816
 817static 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
 826static 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 */
 837static 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
 893err_rmgroup:
 894        remove_dock_dependent_devices(dock_station);
 895        sysfs_remove_group(&dd->dev.kobj, &dock_attribute_group);
 896err_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 */
 911static acpi_status __init
 912find_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
 920void __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}
 937
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