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 struct atomic_notifier_head dock_notifier_list;
  55
  56static const struct acpi_device_id dock_device_ids[] = {
  57        {"LNXDOCK", 0},
  58        {"", 0},
  59};
  60MODULE_DEVICE_TABLE(acpi, dock_device_ids);
  61
  62struct dock_station {
  63        acpi_handle handle;
  64        unsigned long last_dock_time;
  65        u32 flags;
  66        spinlock_t dd_lock;
  67        struct mutex hp_lock;
  68        struct list_head dependent_devices;
  69
  70        struct list_head sibling;
  71        struct platform_device *dock_device;
  72};
  73static LIST_HEAD(dock_stations);
  74static int dock_station_count;
  75static DEFINE_MUTEX(hotplug_lock);
  76
  77struct dock_dependent_device {
  78        struct list_head list;
  79        acpi_handle handle;
  80        const struct acpi_dock_ops *hp_ops;
  81        void *hp_context;
  82        unsigned int hp_refcount;
  83        void (*hp_release)(void *);
  84};
  85
  86#define DOCK_DOCKING    0x00000001
  87#define DOCK_UNDOCKING  0x00000002
  88#define DOCK_IS_DOCK    0x00000010
  89#define DOCK_IS_ATA     0x00000020
  90#define DOCK_IS_BAT     0x00000040
  91#define DOCK_EVENT      3
  92#define UNDOCK_EVENT    2
  93
  94/*****************************************************************************
  95 *                         Dock Dependent device functions                   *
  96 *****************************************************************************/
  97/**
  98 * add_dock_dependent_device - associate a device with the dock station
  99 * @ds: The dock station
 100 * @handle: handle of the dependent device
 101 *
 102 * Add the dependent device to the dock's dependent device list.
 103 */
 104static int
 105add_dock_dependent_device(struct dock_station *ds, acpi_handle handle)
 106{
 107        struct dock_dependent_device *dd;
 108
 109        dd = kzalloc(sizeof(*dd), GFP_KERNEL);
 110        if (!dd)
 111                return -ENOMEM;
 112
 113        dd->handle = handle;
 114        INIT_LIST_HEAD(&dd->list);
 115
 116        spin_lock(&ds->dd_lock);
 117        list_add_tail(&dd->list, &ds->dependent_devices);
 118        spin_unlock(&ds->dd_lock);
 119
 120        return 0;
 121}
 122
 123/**
 124 * dock_init_hotplug - Initialize a hotplug device on a docking station.
 125 * @dd: Dock-dependent device.
 126 * @ops: Dock operations to attach to the dependent device.
 127 * @context: Data to pass to the @ops callbacks and @release.
 128 * @init: Optional initialization routine to run after setting up context.
 129 * @release: Optional release routine to run on removal.
 130 */
 131static int dock_init_hotplug(struct dock_dependent_device *dd,
 132                             const struct acpi_dock_ops *ops, void *context,
 133                             void (*init)(void *), void (*release)(void *))
 134{
 135        int ret = 0;
 136
 137        mutex_lock(&hotplug_lock);
 138
 139        if (dd->hp_context) {
 140                ret = -EEXIST;
 141        } else {
 142                dd->hp_refcount = 1;
 143                dd->hp_ops = ops;
 144                dd->hp_context = context;
 145                dd->hp_release = release;
 146        }
 147
 148        if (!WARN_ON(ret) && init)
 149                init(context);
 150
 151        mutex_unlock(&hotplug_lock);
 152        return ret;
 153}
 154
 155/**
 156 * dock_release_hotplug - Decrement hotplug reference counter of dock device.
 157 * @dd: Dock-dependent device.
 158 *
 159 * Decrement the reference counter of @dd and if 0, detach its hotplug
 160 * operations from it, reset its context pointer and run the optional release
 161 * routine if present.
 162 */
 163static void dock_release_hotplug(struct dock_dependent_device *dd)
 164{
 165        void (*release)(void *) = NULL;
 166        void *context = NULL;
 167
 168        mutex_lock(&hotplug_lock);
 169
 170        if (dd->hp_context && !--dd->hp_refcount) {
 171                dd->hp_ops = NULL;
 172                context = dd->hp_context;
 173                dd->hp_context = NULL;
 174                release = dd->hp_release;
 175                dd->hp_release = NULL;
 176        }
 177
 178        if (release && context)
 179                release(context);
 180
 181        mutex_unlock(&hotplug_lock);
 182}
 183
 184static void dock_hotplug_event(struct dock_dependent_device *dd, u32 event,
 185                               bool uevent)
 186{
 187        acpi_notify_handler cb = NULL;
 188        bool run = false;
 189
 190        mutex_lock(&hotplug_lock);
 191
 192        if (dd->hp_context) {
 193                run = true;
 194                dd->hp_refcount++;
 195                if (dd->hp_ops)
 196                        cb = uevent ? dd->hp_ops->uevent : dd->hp_ops->handler;
 197        }
 198
 199        mutex_unlock(&hotplug_lock);
 200
 201        if (!run)
 202                return;
 203
 204        if (cb)
 205                cb(dd->handle, event, dd->hp_context);
 206
 207        dock_release_hotplug(dd);
 208}
 209
 210/**
 211 * find_dock_dependent_device - get a device dependent on this dock
 212 * @ds: the dock station
 213 * @handle: the acpi_handle of the device we want
 214 *
 215 * iterate over the dependent device list for this dock.  If the
 216 * dependent device matches the handle, return.
 217 */
 218static struct dock_dependent_device *
 219find_dock_dependent_device(struct dock_station *ds, acpi_handle handle)
 220{
 221        struct dock_dependent_device *dd;
 222
 223        spin_lock(&ds->dd_lock);
 224        list_for_each_entry(dd, &ds->dependent_devices, list) {
 225                if (handle == dd->handle) {
 226                        spin_unlock(&ds->dd_lock);
 227                        return dd;
 228                }
 229        }
 230        spin_unlock(&ds->dd_lock);
 231        return NULL;
 232}
 233
 234/*****************************************************************************
 235 *                         Dock functions                                    *
 236 *****************************************************************************/
 237/**
 238 * is_dock - see if a device is a dock station
 239 * @handle: acpi handle of the device
 240 *
 241 * If an acpi object has a _DCK method, then it is by definition a dock
 242 * station, so return true.
 243 */
 244static int is_dock(acpi_handle handle)
 245{
 246        acpi_status status;
 247        acpi_handle tmp;
 248
 249        status = acpi_get_handle(handle, "_DCK", &tmp);
 250        if (ACPI_FAILURE(status))
 251                return 0;
 252        return 1;
 253}
 254
 255static int is_ejectable(acpi_handle handle)
 256{
 257        acpi_status status;
 258        acpi_handle tmp;
 259
 260        status = acpi_get_handle(handle, "_EJ0", &tmp);
 261        if (ACPI_FAILURE(status))
 262                return 0;
 263        return 1;
 264}
 265
 266static int is_ata(acpi_handle handle)
 267{
 268        acpi_handle tmp;
 269
 270        if ((ACPI_SUCCESS(acpi_get_handle(handle, "_GTF", &tmp))) ||
 271           (ACPI_SUCCESS(acpi_get_handle(handle, "_GTM", &tmp))) ||
 272           (ACPI_SUCCESS(acpi_get_handle(handle, "_STM", &tmp))) ||
 273           (ACPI_SUCCESS(acpi_get_handle(handle, "_SDD", &tmp))))
 274                return 1;
 275
 276        return 0;
 277}
 278
 279static int is_battery(acpi_handle handle)
 280{
 281        struct acpi_device_info *info;
 282        int ret = 1;
 283
 284        if (!ACPI_SUCCESS(acpi_get_object_info(handle, &info)))
 285                return 0;
 286        if (!(info->valid & ACPI_VALID_HID))
 287                ret = 0;
 288        else
 289                ret = !strcmp("PNP0C0A", info->hardware_id.string);
 290
 291        kfree(info);
 292        return ret;
 293}
 294
 295static int is_ejectable_bay(acpi_handle handle)
 296{
 297        acpi_handle phandle;
 298
 299        if (!is_ejectable(handle))
 300                return 0;
 301        if (is_battery(handle) || is_ata(handle))
 302                return 1;
 303        if (!acpi_get_parent(handle, &phandle) && is_ata(phandle))
 304                return 1;
 305        return 0;
 306}
 307
 308/**
 309 * is_dock_device - see if a device is on a dock station
 310 * @handle: acpi handle of the device
 311 *
 312 * If this device is either the dock station itself,
 313 * or is a device dependent on the dock station, then it
 314 * is a dock device
 315 */
 316int is_dock_device(acpi_handle handle)
 317{
 318        struct dock_station *dock_station;
 319
 320        if (!dock_station_count)
 321                return 0;
 322
 323        if (is_dock(handle))
 324                return 1;
 325
 326        list_for_each_entry(dock_station, &dock_stations, sibling)
 327                if (find_dock_dependent_device(dock_station, handle))
 328                        return 1;
 329
 330        return 0;
 331}
 332EXPORT_SYMBOL_GPL(is_dock_device);
 333
 334/**
 335 * dock_present - see if the dock station is present.
 336 * @ds: the dock station
 337 *
 338 * execute the _STA method.  note that present does not
 339 * imply that we are docked.
 340 */
 341static int dock_present(struct dock_station *ds)
 342{
 343        unsigned long long sta;
 344        acpi_status status;
 345
 346        if (ds) {
 347                status = acpi_evaluate_integer(ds->handle, "_STA", NULL, &sta);
 348                if (ACPI_SUCCESS(status) && sta)
 349                        return 1;
 350        }
 351        return 0;
 352}
 353
 354/**
 355 * dock_create_acpi_device - add new devices to acpi
 356 * @handle - handle of the device to add
 357 *
 358 *  This function will create a new acpi_device for the given
 359 *  handle if one does not exist already.  This should cause
 360 *  acpi to scan for drivers for the given devices, and call
 361 *  matching driver's add routine.
 362 *
 363 *  Returns a pointer to the acpi_device corresponding to the handle.
 364 */
 365static struct acpi_device * dock_create_acpi_device(acpi_handle handle)
 366{
 367        struct acpi_device *device;
 368        int ret;
 369
 370        if (acpi_bus_get_device(handle, &device)) {
 371                /*
 372                 * no device created for this object,
 373                 * so we should create one.
 374                 */
 375                ret = acpi_bus_scan(handle);
 376                if (ret)
 377                        pr_debug("error adding bus, %x\n", -ret);
 378
 379                acpi_bus_get_device(handle, &device);
 380        }
 381        return device;
 382}
 383
 384/**
 385 * dock_remove_acpi_device - remove the acpi_device struct from acpi
 386 * @handle - the handle of the device to remove
 387 *
 388 *  Tell acpi to remove the acpi_device.  This should cause any loaded
 389 *  driver to have it's remove routine called.
 390 */
 391static void dock_remove_acpi_device(acpi_handle handle)
 392{
 393        struct acpi_device *device;
 394
 395        if (!acpi_bus_get_device(handle, &device))
 396                acpi_bus_trim(device);
 397}
 398
 399/**
 400 * hotplug_dock_devices - insert or remove devices on the dock station
 401 * @ds: the dock station
 402 * @event: either bus check or eject request
 403 *
 404 * Some devices on the dock station need to have drivers called
 405 * to perform hotplug operations after a dock event has occurred.
 406 * Traverse the list of dock devices that have registered a
 407 * hotplug handler, and call the handler.
 408 */
 409static void hotplug_dock_devices(struct dock_station *ds, u32 event)
 410{
 411        struct dock_dependent_device *dd;
 412
 413        mutex_lock(&ds->hp_lock);
 414
 415        /*
 416         * First call driver specific hotplug functions
 417         */
 418        list_for_each_entry(dd, &ds->dependent_devices, list)
 419                dock_hotplug_event(dd, event, false);
 420
 421        /*
 422         * Now make sure that an acpi_device is created for each
 423         * dependent device, or removed if this is an eject request.
 424         * This will cause acpi_drivers to be stopped/started if they
 425         * exist
 426         */
 427        list_for_each_entry(dd, &ds->dependent_devices, list) {
 428                if (event == ACPI_NOTIFY_EJECT_REQUEST)
 429                        dock_remove_acpi_device(dd->handle);
 430                else
 431                        dock_create_acpi_device(dd->handle);
 432        }
 433        mutex_unlock(&ds->hp_lock);
 434}
 435
 436static void dock_event(struct dock_station *ds, u32 event, int num)
 437{
 438        struct device *dev = &ds->dock_device->dev;
 439        char event_string[13];
 440        char *envp[] = { event_string, NULL };
 441        struct dock_dependent_device *dd;
 442
 443        if (num == UNDOCK_EVENT)
 444                sprintf(event_string, "EVENT=undock");
 445        else
 446                sprintf(event_string, "EVENT=dock");
 447
 448        /*
 449         * Indicate that the status of the dock station has
 450         * changed.
 451         */
 452        if (num == DOCK_EVENT)
 453                kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp);
 454
 455        list_for_each_entry(dd, &ds->dependent_devices, list)
 456                dock_hotplug_event(dd, event, true);
 457
 458        if (num != DOCK_EVENT)
 459                kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp);
 460}
 461
 462/**
 463 * eject_dock - respond to a dock eject request
 464 * @ds: the dock station
 465 *
 466 * This is called after _DCK is called, to execute the dock station's
 467 * _EJ0 method.
 468 */
 469static void eject_dock(struct dock_station *ds)
 470{
 471        struct acpi_object_list arg_list;
 472        union acpi_object arg;
 473        acpi_status status;
 474        acpi_handle tmp;
 475
 476        /* all dock devices should have _EJ0, but check anyway */
 477        status = acpi_get_handle(ds->handle, "_EJ0", &tmp);
 478        if (ACPI_FAILURE(status)) {
 479                pr_debug("No _EJ0 support for dock device\n");
 480                return;
 481        }
 482
 483        arg_list.count = 1;
 484        arg_list.pointer = &arg;
 485        arg.type = ACPI_TYPE_INTEGER;
 486        arg.integer.value = 1;
 487
 488        status = acpi_evaluate_object(ds->handle, "_EJ0", &arg_list, NULL);
 489        if (ACPI_FAILURE(status))
 490                pr_debug("Failed to evaluate _EJ0!\n");
 491}
 492
 493/**
 494 * handle_dock - handle a dock event
 495 * @ds: the dock station
 496 * @dock: to dock, or undock - that is the question
 497 *
 498 * Execute the _DCK method in response to an acpi event
 499 */
 500static void handle_dock(struct dock_station *ds, int dock)
 501{
 502        acpi_status status;
 503        struct acpi_object_list arg_list;
 504        union acpi_object arg;
 505        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 506
 507        acpi_handle_info(ds->handle, "%s\n", dock ? "docking" : "undocking");
 508
 509        /* _DCK method has one argument */
 510        arg_list.count = 1;
 511        arg_list.pointer = &arg;
 512        arg.type = ACPI_TYPE_INTEGER;
 513        arg.integer.value = dock;
 514        status = acpi_evaluate_object(ds->handle, "_DCK", &arg_list, &buffer);
 515        if (ACPI_FAILURE(status) && status != AE_NOT_FOUND)
 516                acpi_handle_err(ds->handle, "Failed to execute _DCK (0x%x)\n",
 517                                status);
 518
 519        kfree(buffer.pointer);
 520}
 521
 522static inline void dock(struct dock_station *ds)
 523{
 524        handle_dock(ds, 1);
 525}
 526
 527static inline void undock(struct dock_station *ds)
 528{
 529        handle_dock(ds, 0);
 530}
 531
 532static inline void begin_dock(struct dock_station *ds)
 533{
 534        ds->flags |= DOCK_DOCKING;
 535}
 536
 537static inline void complete_dock(struct dock_station *ds)
 538{
 539        ds->flags &= ~(DOCK_DOCKING);
 540        ds->last_dock_time = jiffies;
 541}
 542
 543static inline void begin_undock(struct dock_station *ds)
 544{
 545        ds->flags |= DOCK_UNDOCKING;
 546}
 547
 548static inline void complete_undock(struct dock_station *ds)
 549{
 550        ds->flags &= ~(DOCK_UNDOCKING);
 551}
 552
 553static void dock_lock(struct dock_station *ds, int lock)
 554{
 555        struct acpi_object_list arg_list;
 556        union acpi_object arg;
 557        acpi_status status;
 558
 559        arg_list.count = 1;
 560        arg_list.pointer = &arg;
 561        arg.type = ACPI_TYPE_INTEGER;
 562        arg.integer.value = !!lock;
 563        status = acpi_evaluate_object(ds->handle, "_LCK", &arg_list, NULL);
 564        if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 565                if (lock)
 566                        acpi_handle_warn(ds->handle,
 567                                "Locking device failed (0x%x)\n", status);
 568                else
 569                        acpi_handle_warn(ds->handle,
 570                                "Unlocking device failed (0x%x)\n", status);
 571        }
 572}
 573
 574/**
 575 * dock_in_progress - see if we are in the middle of handling a dock event
 576 * @ds: the dock station
 577 *
 578 * Sometimes while docking, false dock events can be sent to the driver
 579 * because good connections aren't made or some other reason.  Ignore these
 580 * if we are in the middle of doing something.
 581 */
 582static int dock_in_progress(struct dock_station *ds)
 583{
 584        if ((ds->flags & DOCK_DOCKING) ||
 585            time_before(jiffies, (ds->last_dock_time + HZ)))
 586                return 1;
 587        return 0;
 588}
 589
 590/**
 591 * register_dock_notifier - add yourself to the dock notifier list
 592 * @nb: the callers notifier block
 593 *
 594 * If a driver wishes to be notified about dock events, they can
 595 * use this function to put a notifier block on the dock notifier list.
 596 * this notifier call chain will be called after a dock event, but
 597 * before hotplugging any new devices.
 598 */
 599int register_dock_notifier(struct notifier_block *nb)
 600{
 601        if (!dock_station_count)
 602                return -ENODEV;
 603
 604        return atomic_notifier_chain_register(&dock_notifier_list, nb);
 605}
 606EXPORT_SYMBOL_GPL(register_dock_notifier);
 607
 608/**
 609 * unregister_dock_notifier - remove yourself from the dock notifier list
 610 * @nb: the callers notifier block
 611 */
 612void unregister_dock_notifier(struct notifier_block *nb)
 613{
 614        if (!dock_station_count)
 615                return;
 616
 617        atomic_notifier_chain_unregister(&dock_notifier_list, nb);
 618}
 619EXPORT_SYMBOL_GPL(unregister_dock_notifier);
 620
 621/**
 622 * register_hotplug_dock_device - register a hotplug function
 623 * @handle: the handle of the device
 624 * @ops: handlers to call after docking
 625 * @context: device specific data
 626 * @init: Optional initialization routine to run after registration
 627 * @release: Optional release routine to run on unregistration
 628 *
 629 * If a driver would like to perform a hotplug operation after a dock
 630 * event, they can register an acpi_notifiy_handler to be called by
 631 * the dock driver after _DCK is executed.
 632 */
 633int register_hotplug_dock_device(acpi_handle handle,
 634                                 const struct acpi_dock_ops *ops, void *context,
 635                                 void (*init)(void *), void (*release)(void *))
 636{
 637        struct dock_dependent_device *dd;
 638        struct dock_station *dock_station;
 639        int ret = -EINVAL;
 640
 641        if (WARN_ON(!context))
 642                return -EINVAL;
 643
 644        if (!dock_station_count)
 645                return -ENODEV;
 646
 647        /*
 648         * make sure this handle is for a device dependent on the dock,
 649         * this would include the dock station itself
 650         */
 651        list_for_each_entry(dock_station, &dock_stations, sibling) {
 652                /*
 653                 * An ATA bay can be in a dock and itself can be ejected
 654                 * separately, so there are two 'dock stations' which need the
 655                 * ops
 656                 */
 657                dd = find_dock_dependent_device(dock_station, handle);
 658                if (dd && !dock_init_hotplug(dd, ops, context, init, release))
 659                        ret = 0;
 660        }
 661
 662        return ret;
 663}
 664EXPORT_SYMBOL_GPL(register_hotplug_dock_device);
 665
 666/**
 667 * unregister_hotplug_dock_device - remove yourself from the hotplug list
 668 * @handle: the acpi handle of the device
 669 */
 670void unregister_hotplug_dock_device(acpi_handle handle)
 671{
 672        struct dock_dependent_device *dd;
 673        struct dock_station *dock_station;
 674
 675        if (!dock_station_count)
 676                return;
 677
 678        list_for_each_entry(dock_station, &dock_stations, sibling) {
 679                dd = find_dock_dependent_device(dock_station, handle);
 680                if (dd)
 681                        dock_release_hotplug(dd);
 682        }
 683}
 684EXPORT_SYMBOL_GPL(unregister_hotplug_dock_device);
 685
 686/**
 687 * handle_eject_request - handle an undock request checking for error conditions
 688 *
 689 * Check to make sure the dock device is still present, then undock and
 690 * hotremove all the devices that may need removing.
 691 */
 692static int handle_eject_request(struct dock_station *ds, u32 event)
 693{
 694        if (dock_in_progress(ds))
 695                return -EBUSY;
 696
 697        /*
 698         * here we need to generate the undock
 699         * event prior to actually doing the undock
 700         * so that the device struct still exists.
 701         * Also, even send the dock event if the
 702         * device is not present anymore
 703         */
 704        dock_event(ds, event, UNDOCK_EVENT);
 705
 706        hotplug_dock_devices(ds, ACPI_NOTIFY_EJECT_REQUEST);
 707        undock(ds);
 708        dock_lock(ds, 0);
 709        eject_dock(ds);
 710        if (dock_present(ds)) {
 711                acpi_handle_err(ds->handle, "Unable to undock!\n");
 712                return -EBUSY;
 713        }
 714        complete_undock(ds);
 715        return 0;
 716}
 717
 718/**
 719 * dock_notify - act upon an acpi dock notification
 720 * @handle: the dock station handle
 721 * @event: the acpi event
 722 * @data: our driver data struct
 723 *
 724 * If we are notified to dock, then check to see if the dock is
 725 * present and then dock.  Notify all drivers of the dock event,
 726 * and then hotplug and devices that may need hotplugging.
 727 */
 728static void dock_notify(acpi_handle handle, u32 event, void *data)
 729{
 730        struct dock_station *ds = data;
 731        struct acpi_device *tmp;
 732        int surprise_removal = 0;
 733
 734        /*
 735         * According to acpi spec 3.0a, if a DEVICE_CHECK notification
 736         * is sent and _DCK is present, it is assumed to mean an undock
 737         * request.
 738         */
 739        if ((ds->flags & DOCK_IS_DOCK) && event == ACPI_NOTIFY_DEVICE_CHECK)
 740                event = ACPI_NOTIFY_EJECT_REQUEST;
 741
 742        /*
 743         * dock station: BUS_CHECK - docked or surprise removal
 744         *               DEVICE_CHECK - undocked
 745         * other device: BUS_CHECK/DEVICE_CHECK - added or surprise removal
 746         *
 747         * To simplify event handling, dock dependent device handler always
 748         * get ACPI_NOTIFY_BUS_CHECK/ACPI_NOTIFY_DEVICE_CHECK for add and
 749         * ACPI_NOTIFY_EJECT_REQUEST for removal
 750         */
 751        switch (event) {
 752        case ACPI_NOTIFY_BUS_CHECK:
 753        case ACPI_NOTIFY_DEVICE_CHECK:
 754                if (!dock_in_progress(ds) && acpi_bus_get_device(ds->handle,
 755                   &tmp)) {
 756                        begin_dock(ds);
 757                        dock(ds);
 758                        if (!dock_present(ds)) {
 759                                acpi_handle_err(handle, "Unable to dock!\n");
 760                                complete_dock(ds);
 761                                break;
 762                        }
 763                        atomic_notifier_call_chain(&dock_notifier_list,
 764                                                   event, NULL);
 765                        hotplug_dock_devices(ds, event);
 766                        complete_dock(ds);
 767                        dock_event(ds, event, DOCK_EVENT);
 768                        dock_lock(ds, 1);
 769                        acpi_update_all_gpes();
 770                        break;
 771                }
 772                if (dock_present(ds) || dock_in_progress(ds))
 773                        break;
 774                /* This is a surprise removal */
 775                surprise_removal = 1;
 776                event = ACPI_NOTIFY_EJECT_REQUEST;
 777                /* Fall back */
 778        case ACPI_NOTIFY_EJECT_REQUEST:
 779                begin_undock(ds);
 780                if ((immediate_undock && !(ds->flags & DOCK_IS_ATA))
 781                   || surprise_removal)
 782                        handle_eject_request(ds, event);
 783                else
 784                        dock_event(ds, event, UNDOCK_EVENT);
 785                break;
 786        default:
 787                acpi_handle_err(handle, "Unknown dock event %d\n", event);
 788        }
 789}
 790
 791struct dock_data {
 792        acpi_handle handle;
 793        unsigned long event;
 794        struct dock_station *ds;
 795};
 796
 797static void acpi_dock_deferred_cb(void *context)
 798{
 799        struct dock_data *data = context;
 800
 801        acpi_scan_lock_acquire();
 802        dock_notify(data->handle, data->event, data->ds);
 803        acpi_scan_lock_release();
 804        kfree(data);
 805}
 806
 807static int acpi_dock_notifier_call(struct notifier_block *this,
 808        unsigned long event, void *data)
 809{
 810        struct dock_station *dock_station;
 811        acpi_handle handle = data;
 812
 813        if (event != ACPI_NOTIFY_BUS_CHECK && event != ACPI_NOTIFY_DEVICE_CHECK
 814           && event != ACPI_NOTIFY_EJECT_REQUEST)
 815                return 0;
 816
 817        acpi_scan_lock_acquire();
 818
 819        list_for_each_entry(dock_station, &dock_stations, sibling) {
 820                if (dock_station->handle == handle) {
 821                        struct dock_data *dd;
 822                        acpi_status status;
 823
 824                        dd = kmalloc(sizeof(*dd), GFP_KERNEL);
 825                        if (!dd)
 826                                break;
 827
 828                        dd->handle = handle;
 829                        dd->event = event;
 830                        dd->ds = dock_station;
 831                        status = acpi_os_hotplug_execute(acpi_dock_deferred_cb,
 832                                                         dd);
 833                        if (ACPI_FAILURE(status))
 834                                kfree(dd);
 835
 836                        break;
 837                }
 838        }
 839
 840        acpi_scan_lock_release();
 841        return 0;
 842}
 843
 844static struct notifier_block dock_acpi_notifier = {
 845        .notifier_call = acpi_dock_notifier_call,
 846};
 847
 848/**
 849 * find_dock_devices - find devices on the dock station
 850 * @handle: the handle of the device we are examining
 851 * @lvl: unused
 852 * @context: the dock station private data
 853 * @rv: unused
 854 *
 855 * This function is called by acpi_walk_namespace.  It will
 856 * check to see if an object has an _EJD method.  If it does, then it
 857 * will see if it is dependent on the dock station.
 858 */
 859static acpi_status
 860find_dock_devices(acpi_handle handle, u32 lvl, void *context, void **rv)
 861{
 862        acpi_status status;
 863        acpi_handle tmp, parent;
 864        struct dock_station *ds = context;
 865
 866        status = acpi_bus_get_ejd(handle, &tmp);
 867        if (ACPI_FAILURE(status)) {
 868                /* try the parent device as well */
 869                status = acpi_get_parent(handle, &parent);
 870                if (ACPI_FAILURE(status))
 871                        goto fdd_out;
 872                /* see if parent is dependent on dock */
 873                status = acpi_bus_get_ejd(parent, &tmp);
 874                if (ACPI_FAILURE(status))
 875                        goto fdd_out;
 876        }
 877
 878        if (tmp == ds->handle)
 879                add_dock_dependent_device(ds, handle);
 880
 881fdd_out:
 882        return AE_OK;
 883}
 884
 885/*
 886 * show_docked - read method for "docked" file in sysfs
 887 */
 888static ssize_t show_docked(struct device *dev,
 889                           struct device_attribute *attr, char *buf)
 890{
 891        struct acpi_device *tmp;
 892
 893        struct dock_station *dock_station = dev->platform_data;
 894
 895        if (!acpi_bus_get_device(dock_station->handle, &tmp))
 896                return snprintf(buf, PAGE_SIZE, "1\n");
 897        return snprintf(buf, PAGE_SIZE, "0\n");
 898}
 899static DEVICE_ATTR(docked, S_IRUGO, show_docked, NULL);
 900
 901/*
 902 * show_flags - read method for flags file in sysfs
 903 */
 904static ssize_t show_flags(struct device *dev,
 905                          struct device_attribute *attr, char *buf)
 906{
 907        struct dock_station *dock_station = dev->platform_data;
 908        return snprintf(buf, PAGE_SIZE, "%d\n", dock_station->flags);
 909
 910}
 911static DEVICE_ATTR(flags, S_IRUGO, show_flags, NULL);
 912
 913/*
 914 * write_undock - write method for "undock" file in sysfs
 915 */
 916static ssize_t write_undock(struct device *dev, struct device_attribute *attr,
 917                           const char *buf, size_t count)
 918{
 919        int ret;
 920        struct dock_station *dock_station = dev->platform_data;
 921
 922        if (!count)
 923                return -EINVAL;
 924
 925        acpi_scan_lock_acquire();
 926        begin_undock(dock_station);
 927        ret = handle_eject_request(dock_station, ACPI_NOTIFY_EJECT_REQUEST);
 928        acpi_scan_lock_release();
 929        return ret ? ret: count;
 930}
 931static DEVICE_ATTR(undock, S_IWUSR, NULL, write_undock);
 932
 933/*
 934 * show_dock_uid - read method for "uid" file in sysfs
 935 */
 936static ssize_t show_dock_uid(struct device *dev,
 937                             struct device_attribute *attr, char *buf)
 938{
 939        unsigned long long lbuf;
 940        struct dock_station *dock_station = dev->platform_data;
 941        acpi_status status = acpi_evaluate_integer(dock_station->handle,
 942                                        "_UID", NULL, &lbuf);
 943        if (ACPI_FAILURE(status))
 944            return 0;
 945
 946        return snprintf(buf, PAGE_SIZE, "%llx\n", lbuf);
 947}
 948static DEVICE_ATTR(uid, S_IRUGO, show_dock_uid, NULL);
 949
 950static ssize_t show_dock_type(struct device *dev,
 951                struct device_attribute *attr, char *buf)
 952{
 953        struct dock_station *dock_station = dev->platform_data;
 954        char *type;
 955
 956        if (dock_station->flags & DOCK_IS_DOCK)
 957                type = "dock_station";
 958        else if (dock_station->flags & DOCK_IS_ATA)
 959                type = "ata_bay";
 960        else if (dock_station->flags & DOCK_IS_BAT)
 961                type = "battery_bay";
 962        else
 963                type = "unknown";
 964
 965        return snprintf(buf, PAGE_SIZE, "%s\n", type);
 966}
 967static DEVICE_ATTR(type, S_IRUGO, show_dock_type, NULL);
 968
 969static struct attribute *dock_attributes[] = {
 970        &dev_attr_docked.attr,
 971        &dev_attr_flags.attr,
 972        &dev_attr_undock.attr,
 973        &dev_attr_uid.attr,
 974        &dev_attr_type.attr,
 975        NULL
 976};
 977
 978static struct attribute_group dock_attribute_group = {
 979        .attrs = dock_attributes
 980};
 981
 982/**
 983 * dock_add - add a new dock station
 984 * @handle: the dock station handle
 985 *
 986 * allocated and initialize a new dock station device.  Find all devices
 987 * that are on the dock station, and register for dock event notifications.
 988 */
 989static int __init dock_add(acpi_handle handle)
 990{
 991        int ret, id;
 992        struct dock_station ds, *dock_station;
 993        struct platform_device *dd;
 994
 995        id = dock_station_count;
 996        memset(&ds, 0, sizeof(ds));
 997        dd = platform_device_register_data(NULL, "dock", id, &ds, sizeof(ds));
 998        if (IS_ERR(dd))
 999                return PTR_ERR(dd);
1000
1001        dock_station = dd->dev.platform_data;
1002
1003        dock_station->handle = handle;
1004        dock_station->dock_device = dd;
1005        dock_station->last_dock_time = jiffies - HZ;
1006
1007        mutex_init(&dock_station->hp_lock);
1008        spin_lock_init(&dock_station->dd_lock);
1009        INIT_LIST_HEAD(&dock_station->sibling);
1010        ATOMIC_INIT_NOTIFIER_HEAD(&dock_notifier_list);
1011        INIT_LIST_HEAD(&dock_station->dependent_devices);
1012
1013        /* we want the dock device to send uevents */
1014        dev_set_uevent_suppress(&dd->dev, 0);
1015
1016        if (is_dock(handle))
1017                dock_station->flags |= DOCK_IS_DOCK;
1018        if (is_ata(handle))
1019                dock_station->flags |= DOCK_IS_ATA;
1020        if (is_battery(handle))
1021                dock_station->flags |= DOCK_IS_BAT;
1022
1023        ret = sysfs_create_group(&dd->dev.kobj, &dock_attribute_group);
1024        if (ret)
1025                goto err_unregister;
1026
1027        /* Find dependent devices */
1028        acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
1029                            ACPI_UINT32_MAX, find_dock_devices, NULL,
1030                            dock_station, NULL);
1031
1032        /* add the dock station as a device dependent on itself */
1033        ret = add_dock_dependent_device(dock_station, handle);
1034        if (ret)
1035                goto err_rmgroup;
1036
1037        dock_station_count++;
1038        list_add(&dock_station->sibling, &dock_stations);
1039        return 0;
1040
1041err_rmgroup:
1042        sysfs_remove_group(&dd->dev.kobj, &dock_attribute_group);
1043err_unregister:
1044        platform_device_unregister(dd);
1045        acpi_handle_err(handle, "%s encountered error %d\n", __func__, ret);
1046        return ret;
1047}
1048
1049/**
1050 * find_dock_and_bay - look for dock stations and bays
1051 * @handle: acpi handle of a device
1052 * @lvl: unused
1053 * @context: unused
1054 * @rv: unused
1055 *
1056 * This is called by acpi_walk_namespace to look for dock stations and bays.
1057 */
1058static __init acpi_status
1059find_dock_and_bay(acpi_handle handle, u32 lvl, void *context, void **rv)
1060{
1061        if (is_dock(handle) || is_ejectable_bay(handle))
1062                dock_add(handle);
1063
1064        return AE_OK;
1065}
1066
1067void __init acpi_dock_init(void)
1068{
1069        if (acpi_disabled)
1070                return;
1071
1072        /* look for dock stations and bays */
1073        acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
1074                ACPI_UINT32_MAX, find_dock_and_bay, NULL, NULL, NULL);
1075
1076        if (!dock_station_count) {
1077                pr_info(PREFIX "No dock devices found.\n");
1078                return;
1079        }
1080
1081        register_acpi_bus_notifier(&dock_acpi_notifier);
1082        pr_info(PREFIX "%s: %d docks/bays found\n",
1083                ACPI_DOCK_DRIVER_DESCRIPTION, dock_station_count);
1084}
1085
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