drivers/base/power/main.c

   1 /*
   2  * drivers/base/power/main.c - Where the driver meets power management.
   3  *
   4  * Copyright (c) 2003 Patrick Mochel
   5  * Copyright (c) 2003 Open Source Development Lab
   6  *
   7  * This file is released under the GPLv2
   8  *
   9  *
  10  * The driver model core calls device_pm_add() when a device is registered.
  11  * This will initialize the embedded device_pm_info object in the device
  12  * and add it to the list of power-controlled devices. sysfs entries for
  13  * controlling device power management will also be added.
  14  *
  15  * A separate list is used for keeping track of power info, because the power
  16  * domain dependencies may differ from the ancestral dependencies that the
  17  * subsystem list maintains.
  18  */
  19
  20 #include <linux/device.h>
  21 #include <linux/kallsyms.h>
  22 #include <linux/mutex.h>
  23 #include <linux/pm.h>
  24 #include <linux/pm_runtime.h>
  25 #include <linux/resume-trace.h>
  26 #include <linux/interrupt.h>
  27 #include <linux/sched.h>
  28 #include <linux/async.h>
  29 #include <linux/suspend.h>
  30
  31 #include "../base.h"
  32 #include "power.h"
  33
  34 /*
  35  * The entries in the dpm_list list are in a depth first order, simply
  36  * because children are guaranteed to be discovered after parents, and
  37  * are inserted at the back of the list on discovery.
  38  *
  39  * Since device_pm_add() may be called with a device lock held,
  40  * we must never try to acquire a device lock while holding
  41  * dpm_list_mutex.
  42  */
  43
  44 LIST_HEAD(dpm_list);
  45 LIST_HEAD(dpm_prepared_list);
  46 LIST_HEAD(dpm_suspended_list);
  47 LIST_HEAD(dpm_noirq_list);
  48
  49 static DEFINE_MUTEX(dpm_list_mtx);
  50 static pm_message_t pm_transition;
  51
  52 static int async_error;
  53
  54 /**
  55  * device_pm_init - Initialize the PM-related part of a device object.
  56  * @dev: Device object being initialized.
  57  */
  58 void device_pm_init(struct device *dev)
  59 {
  60         dev->power.in_suspend = false;
  61         init_completion(&dev->power.completion);
  62         complete_all(&dev->power.completion);
  63         dev->power.wakeup = NULL;
  64         spin_lock_init(&dev->power.lock);
  65         pm_runtime_init(dev);
  66 }
  67
  68 /**
  69  * device_pm_lock - Lock the list of active devices used by the PM core.
  70  */
  71 void device_pm_lock(void)
  72 {
  73         mutex_lock(&dpm_list_mtx);
  74 }
  75
  76 /**
  77  * device_pm_unlock - Unlock the list of active devices used by the PM core.
  78  */
  79 void device_pm_unlock(void)
  80 {
  81         mutex_unlock(&dpm_list_mtx);
  82 }
  83
  84 /**
  85  * device_pm_add - Add a device to the PM core's list of active devices.
  86  * @dev: Device to add to the list.
  87  */
  88 void device_pm_add(struct device *dev)
  89 {
  90         pr_debug("PM: Adding info for %s:%s\n",
  91                  dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
  92         mutex_lock(&dpm_list_mtx);
  93         if (dev->parent && dev->parent->power.in_suspend)
  94                 dev_warn(dev, "parent %s should not be sleeping\n",
  95                         dev_name(dev->parent));
  96         list_add_tail(&dev->power.entry, &dpm_list);
  97         mutex_unlock(&dpm_list_mtx);
  98 }
  99
 100 /**
 101  * device_pm_remove - Remove a device from the PM core's list of active devices.
 102  * @dev: Device to be removed from the list.
 103  */
 104 void device_pm_remove(struct device *dev)
 105 {
 106         pr_debug("PM: Removing info for %s:%s\n",
 107                  dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
 108         complete_all(&dev->power.completion);
 109         mutex_lock(&dpm_list_mtx);
 110         list_del_init(&dev->power.entry);
 111         mutex_unlock(&dpm_list_mtx);
 112         device_wakeup_disable(dev);
 113         pm_runtime_remove(dev);
 114 }
 115
 116 /**
 117  * device_pm_move_before - Move device in the PM core's list of active devices.
 118  * @deva: Device to move in dpm_list.
 119  * @devb: Device @deva should come before.
 120  */
 121 void device_pm_move_before(struct device *deva, struct device *devb)
 122 {
 123         pr_debug("PM: Moving %s:%s before %s:%s\n",
 124                  deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
 125                  devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
 126         /* Delete deva from dpm_list and reinsert before devb. */
 127         list_move_tail(&deva->power.entry, &devb->power.entry);
 128 }
 129
 130 /**
 131  * device_pm_move_after - Move device in the PM core's list of active devices.
 132  * @deva: Device to move in dpm_list.
 133  * @devb: Device @deva should come after.
 134  */
 135 void device_pm_move_after(struct device *deva, struct device *devb)
 136 {
 137         pr_debug("PM: Moving %s:%s after %s:%s\n",
 138                  deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
 139                  devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
 140         /* Delete deva from dpm_list and reinsert after devb. */
 141         list_move(&deva->power.entry, &devb->power.entry);
 142 }
 143
 144 /**
 145  * device_pm_move_last - Move device to end of the PM core's list of devices.
 146  * @dev: Device to move in dpm_list.
 147  */
 148 void device_pm_move_last(struct device *dev)
 149 {
 150         pr_debug("PM: Moving %s:%s to end of list\n",
 151                  dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
 152         list_move_tail(&dev->power.entry, &dpm_list);
 153 }
 154
 155 static ktime_t initcall_debug_start(struct device *dev)
 156 {
 157         ktime_t calltime = ktime_set(0, 0);
 158
 159         if (initcall_debug) {
 160                 pr_info("calling  %s+ @ %i\n",
 161                                 dev_name(dev), task_pid_nr(current));
 162                 calltime = ktime_get();
 163         }
 164
 165         return calltime;
 166 }
 167
 168 static void initcall_debug_report(struct device *dev, ktime_t calltime,
 169                                   int error)
 170 {
 171         ktime_t delta, rettime;
 172
 173         if (initcall_debug) {
 174                 rettime = ktime_get();
 175                 delta = ktime_sub(rettime, calltime);
 176                 pr_info("call %s+ returned %d after %Ld usecs\n", dev_name(dev),
 177                         error, (unsigned long long)ktime_to_ns(delta) >> 10);
 178         }
 179 }
 180
 181 /**
 182  * dpm_wait - Wait for a PM operation to complete.
 183  * @dev: Device to wait for.
 184  * @async: If unset, wait only if the device's power.async_suspend flag is set.
 185  */
 186 static void dpm_wait(struct device *dev, bool async)
 187 {
 188         if (!dev)
 189                 return;
 190
 191         if (async || (pm_async_enabled && dev->power.async_suspend))
 192                 wait_for_completion(&dev->power.completion);
 193 }
 194
 195 static int dpm_wait_fn(struct device *dev, void *async_ptr)
 196 {
 197         dpm_wait(dev, *((bool *)async_ptr));
 198         return 0;
 199 }
 200
 201 static void dpm_wait_for_children(struct device *dev, bool async)
 202 {
 203        device_for_each_child(dev, &async, dpm_wait_fn);
 204 }
 205
 206 /**
 207  * pm_op - Execute the PM operation appropriate for given PM event.
 208  * @dev: Device to handle.
 209  * @ops: PM operations to choose from.
 210  * @state: PM transition of the system being carried out.
 211  */
 212 static int pm_op(struct device *dev,
 213                  const struct dev_pm_ops *ops,
 214                  pm_message_t state)
 215 {
 216         int error = 0;
 217         ktime_t calltime;
 218
 219         calltime = initcall_debug_start(dev);
 220
 221         switch (state.event) {
 222 #ifdef CONFIG_SUSPEND
 223         case PM_EVENT_SUSPEND:
 224                 if (ops->suspend) {
 225                         error = ops->suspend(dev);
 226                         suspend_report_result(ops->suspend, error);
 227                 }
 228                 break;
 229         case PM_EVENT_RESUME:
 230                 if (ops->resume) {
 231                         error = ops->resume(dev);
 232                         suspend_report_result(ops->resume, error);
 233                 }
 234                 break;
 235 #endif /* CONFIG_SUSPEND */
 236 #ifdef CONFIG_HIBERNATION
 237         case PM_EVENT_FREEZE:
 238         case PM_EVENT_QUIESCE:
 239                 if (ops->freeze) {
 240                         error = ops->freeze(dev);
 241                         suspend_report_result(ops->freeze, error);
 242                 }
 243                 break;
 244         case PM_EVENT_HIBERNATE:
 245                 if (ops->poweroff) {
 246                         error = ops->poweroff(dev);
 247                         suspend_report_result(ops->poweroff, error);
 248                 }
 249                 break;
 250         case PM_EVENT_THAW:
 251         case PM_EVENT_RECOVER:
 252                 if (ops->thaw) {
 253                         error = ops->thaw(dev);
 254                         suspend_report_result(ops->thaw, error);
 255                 }
 256                 break;
 257         case PM_EVENT_RESTORE:
 258                 if (ops->restore) {
 259                         error = ops->restore(dev);
 260                         suspend_report_result(ops->restore, error);
 261                 }
 262                 break;
 263 #endif /* CONFIG_HIBERNATION */
 264         default:
 265                 error = -EINVAL;
 266         }
 267
 268         initcall_debug_report(dev, calltime, error);
 269
 270         return error;
 271 }
 272
 273 /**
 274  * pm_noirq_op - Execute the PM operation appropriate for given PM event.
 275  * @dev: Device to handle.
 276  * @ops: PM operations to choose from.
 277  * @state: PM transition of the system being carried out.
 278  *
 279  * The driver of @dev will not receive interrupts while this function is being
 280  * executed.
 281  */
 282 static int pm_noirq_op(struct device *dev,
 283                         const struct dev_pm_ops *ops,
 284                         pm_message_t state)
 285 {
 286         int error = 0;
 287         ktime_t calltime = ktime_set(0, 0), delta, rettime;
 288
 289         if (initcall_debug) {
 290                 pr_info("calling  %s+ @ %i, parent: %s\n",
 291                                 dev_name(dev), task_pid_nr(current),
 292                                 dev->parent ? dev_name(dev->parent) : "none");
 293                 calltime = ktime_get();
 294         }
 295
 296         switch (state.event) {
 297 #ifdef CONFIG_SUSPEND
 298         case PM_EVENT_SUSPEND:
 299                 if (ops->suspend_noirq) {
 300                         error = ops->suspend_noirq(dev);
 301                         suspend_report_result(ops->suspend_noirq, error);
 302                 }
 303                 break;
 304         case PM_EVENT_RESUME:
 305                 if (ops->resume_noirq) {
 306                         error = ops->resume_noirq(dev);
 307                         suspend_report_result(ops->resume_noirq, error);
 308                 }
 309                 break;
 310 #endif /* CONFIG_SUSPEND */
 311 #ifdef CONFIG_HIBERNATION
 312         case PM_EVENT_FREEZE:
 313         case PM_EVENT_QUIESCE:
 314                 if (ops->freeze_noirq) {
 315                         error = ops->freeze_noirq(dev);
 316                         suspend_report_result(ops->freeze_noirq, error);
 317                 }
 318                 break;
 319         case PM_EVENT_HIBERNATE:
 320                 if (ops->poweroff_noirq) {
 321                         error = ops->poweroff_noirq(dev);
 322                         suspend_report_result(ops->poweroff_noirq, error);
 323                 }
 324                 break;
 325         case PM_EVENT_THAW:
 326         case PM_EVENT_RECOVER:
 327                 if (ops->thaw_noirq) {
 328                         error = ops->thaw_noirq(dev);
 329                         suspend_report_result(ops->thaw_noirq, error);
 330                 }
 331                 break;
 332         case PM_EVENT_RESTORE:
 333                 if (ops->restore_noirq) {
 334                         error = ops->restore_noirq(dev);
 335                         suspend_report_result(ops->restore_noirq, error);
 336                 }
 337                 break;
 338 #endif /* CONFIG_HIBERNATION */
 339         default:
 340                 error = -EINVAL;
 341         }
 342
 343         if (initcall_debug) {
 344                 rettime = ktime_get();
 345                 delta = ktime_sub(rettime, calltime);
 346                 printk("initcall %s_i+ returned %d after %Ld usecs\n",
 347                         dev_name(dev), error,
 348                         (unsigned long long)ktime_to_ns(delta) >> 10);
 349         }
 350
 351         return error;
 352 }
 353
 354 static char *pm_verb(int event)
 355 {
 356         switch (event) {
 357         case PM_EVENT_SUSPEND:
 358                 return "suspend";
 359         case PM_EVENT_RESUME:
 360                 return "resume";
 361         case PM_EVENT_FREEZE:
 362                 return "freeze";
 363         case PM_EVENT_QUIESCE:
 364                 return "quiesce";
 365         case PM_EVENT_HIBERNATE:
 366                 return "hibernate";
 367         case PM_EVENT_THAW:
 368                 return "thaw";
 369         case PM_EVENT_RESTORE:
 370                 return "restore";
 371         case PM_EVENT_RECOVER:
 372                 return "recover";
 373         default:
 374                 return "(unknown PM event)";
 375         }
 376 }
 377
 378 static void pm_dev_dbg(struct device *dev, pm_message_t state, char *info)
 379 {
 380         dev_dbg(dev, "%s%s%s\n", info, pm_verb(state.event),
 381                 ((state.event & PM_EVENT_SLEEP) && device_may_wakeup(dev)) ?
 382                 ", may wakeup" : "");
 383 }
 384
 385 static void pm_dev_err(struct device *dev, pm_message_t state, char *info,
 386                         int error)
 387 {
 388         printk(KERN_ERR "PM: Device %s failed to %s%s: error %d\n",
 389                 dev_name(dev), pm_verb(state.event), info, error);
 390 }
 391
 392 static void dpm_show_time(ktime_t starttime, pm_message_t state, char *info)
 393 {
 394         ktime_t calltime;
 395         u64 usecs64;
 396         int usecs;
 397
 398         calltime = ktime_get();
 399         usecs64 = ktime_to_ns(ktime_sub(calltime, starttime));
 400         do_div(usecs64, NSEC_PER_USEC);
 401         usecs = usecs64;
 402         if (usecs == 0)
 403                 usecs = 1;
 404         pr_info("PM: %s%s%s of devices complete after %ld.%03ld msecs\n",
 405                 info ?: "", info ? " " : "", pm_verb(state.event),
 406                 usecs / USEC_PER_MSEC, usecs % USEC_PER_MSEC);
 407 }
 408
 409 /*------------------------- Resume routines -------------------------*/
 410
 411 /**
 412  * device_resume_noirq - Execute an "early resume" callback for given device.
 413  * @dev: Device to handle.
 414  * @state: PM transition of the system being carried out.
 415  *
 416  * The driver of @dev will not receive interrupts while this function is being
 417  * executed.
 418  */
 419 static int device_resume_noirq(struct device *dev, pm_message_t state)
 420 {
 421         int error = 0;
 422
 423         TRACE_DEVICE(dev);
 424         TRACE_RESUME(0);
 425
 426         if (dev->pwr_domain) {
 427                 pm_dev_dbg(dev, state, "EARLY power domain ");
 428                 pm_noirq_op(dev, &dev->pwr_domain->ops, state);
 429         }
 430
 431         if (dev->type && dev->type->pm) {
 432                 pm_dev_dbg(dev, state, "EARLY type ");
 433                 error = pm_noirq_op(dev, dev->type->pm, state);
 434         } else if (dev->class && dev->class->pm) {
 435                 pm_dev_dbg(dev, state, "EARLY class ");
 436                 error = pm_noirq_op(dev, dev->class->pm, state);
 437         } else if (dev->bus && dev->bus->pm) {
 438                 pm_dev_dbg(dev, state, "EARLY ");
 439                 error = pm_noirq_op(dev, dev->bus->pm, state);
 440         }
 441
 442         TRACE_RESUME(error);
 443         return error;
 444 }
 445
 446 /**
 447  * dpm_resume_noirq - Execute "early resume" callbacks for non-sysdev devices.
 448  * @state: PM transition of the system being carried out.
 449  *
 450  * Call the "noirq" resume handlers for all devices marked as DPM_OFF_IRQ and
 451  * enable device drivers to receive interrupts.
 452  */
 453 void dpm_resume_noirq(pm_message_t state)
 454 {
 455         ktime_t starttime = ktime_get();
 456
 457         mutex_lock(&dpm_list_mtx);
 458         while (!list_empty(&dpm_noirq_list)) {
 459                 struct device *dev = to_device(dpm_noirq_list.next);
 460                 int error;
 461
 462                 get_device(dev);
 463                 list_move_tail(&dev->power.entry, &dpm_suspended_list);
 464                 mutex_unlock(&dpm_list_mtx);
 465
 466                 error = device_resume_noirq(dev, state);
 467                 if (error)
 468                         pm_dev_err(dev, state, " early", error);
 469
 470                 mutex_lock(&dpm_list_mtx);
 471                 put_device(dev);
 472         }
 473         mutex_unlock(&dpm_list_mtx);
 474         dpm_show_time(starttime, state, "early");
 475         resume_device_irqs();
 476 }
 477 EXPORT_SYMBOL_GPL(dpm_resume_noirq);
 478
 479 /**
 480  * legacy_resume - Execute a legacy (bus or class) resume callback for device.
 481  * @dev: Device to resume.
 482  * @cb: Resume callback to execute.
 483  */
 484 static int legacy_resume(struct device *dev, int (*cb)(struct device *dev))
 485 {
 486         int error;
 487         ktime_t calltime;
 488
 489         calltime = initcall_debug_start(dev);
 490
 491         error = cb(dev);
 492         suspend_report_result(cb, error);
 493
 494         initcall_debug_report(dev, calltime, error);
 495
 496         return error;
 497 }
 498
 499 /**
 500  * device_resume - Execute "resume" callbacks for given device.
 501  * @dev: Device to handle.
 502  * @state: PM transition of the system being carried out.
 503  * @async: If true, the device is being resumed asynchronously.
 504  */
 505 static int device_resume(struct device *dev, pm_message_t state, bool async)
 506 {
 507         int error = 0;
 508
 509         TRACE_DEVICE(dev);
 510         TRACE_RESUME(0);
 511
 512         dpm_wait(dev->parent, async);
 513         device_lock(dev);
 514
 515         dev->power.in_suspend = false;
 516
 517         if (dev->pwr_domain) {
 518                 pm_dev_dbg(dev, state, "power domain ");
 519                 pm_op(dev, &dev->pwr_domain->ops, state);
 520         }
 521
 522         if (dev->type && dev->type->pm) {
 523                 pm_dev_dbg(dev, state, "type ");
 524                 error = pm_op(dev, dev->type->pm, state);
 525                 goto End;
 526         }
 527
 528         if (dev->class) {
 529                 if (dev->class->pm) {
 530                         pm_dev_dbg(dev, state, "class ");
 531                         error = pm_op(dev, dev->class->pm, state);
 532                         goto End;
 533                 } else if (dev->class->resume) {
 534                         pm_dev_dbg(dev, state, "legacy class ");
 535                         error = legacy_resume(dev, dev->class->resume);
 536                         goto End;
 537                 }
 538         }
 539
 540         if (dev->bus) {
 541                 if (dev->bus->pm) {
 542                         pm_dev_dbg(dev, state, "");
 543                         error = pm_op(dev, dev->bus->pm, state);
 544                 } else if (dev->bus->resume) {
 545                         pm_dev_dbg(dev, state, "legacy ");
 546                         error = legacy_resume(dev, dev->bus->resume);
 547                 }
 548         }
 549
 550  End:
 551         device_unlock(dev);
 552         complete_all(&dev->power.completion);
 553
 554         TRACE_RESUME(error);
 555         return error;
 556 }
 557
 558 static void async_resume(void *data, async_cookie_t cookie)
 559 {
 560         struct device *dev = (struct device *)data;
 561         int error;
 562
 563         error = device_resume(dev, pm_transition, true);
 564         if (error)
 565                 pm_dev_err(dev, pm_transition, " async", error);
 566         put_device(dev);
 567 }
 568
 569 static bool is_async(struct device *dev)
 570 {
 571         return dev->power.async_suspend && pm_async_enabled
 572                 && !pm_trace_is_enabled();
 573 }
 574
 575 /**
 576  * dpm_resume - Execute "resume" callbacks for non-sysdev devices.
 577  * @state: PM transition of the system being carried out.
 578  *
 579  * Execute the appropriate "resume" callback for all devices whose status
 580  * indicates that they are suspended.
 581  */
 582 static void dpm_resume(pm_message_t state)
 583 {
 584         struct device *dev;
 585         ktime_t starttime = ktime_get();
 586
 587         mutex_lock(&dpm_list_mtx);
 588         pm_transition = state;
 589         async_error = 0;
 590
 591         list_for_each_entry(dev, &dpm_suspended_list, power.entry) {
 592                 INIT_COMPLETION(dev->power.completion);
 593                 if (is_async(dev)) {
 594                         get_device(dev);
 595                         async_schedule(async_resume, dev);
 596                 }
 597         }
 598
 599         while (!list_empty(&dpm_suspended_list)) {
 600                 dev = to_device(dpm_suspended_list.next);
 601                 get_device(dev);
 602                 if (!is_async(dev)) {
 603                         int error;
 604
 605                         mutex_unlock(&dpm_list_mtx);
 606
 607                         error = device_resume(dev, state, false);
 608                         if (error)
 609                                 pm_dev_err(dev, state, "", error);
 610
 611                         mutex_lock(&dpm_list_mtx);
 612                 }
 613                 if (!list_empty(&dev->power.entry))
 614                         list_move_tail(&dev->power.entry, &dpm_prepared_list);
 615                 put_device(dev);
 616         }
 617         mutex_unlock(&dpm_list_mtx);
 618         async_synchronize_full();
 619         dpm_show_time(starttime, state, NULL);
 620 }
 621
 622 /**
 623  * device_complete - Complete a PM transition for given device.
 624  * @dev: Device to handle.
 625  * @state: PM transition of the system being carried out.
 626  */
 627 static void device_complete(struct device *dev, pm_message_t state)
 628 {
 629         device_lock(dev);
 630
 631         if (dev->pwr_domain && dev->pwr_domain->ops.complete) {
 632                 pm_dev_dbg(dev, state, "completing power domain ");
 633                 dev->pwr_domain->ops.complete(dev);
 634         }
 635
 636         if (dev->type && dev->type->pm) {
 637                 pm_dev_dbg(dev, state, "completing type ");
 638                 if (dev->type->pm->complete)
 639                         dev->type->pm->complete(dev);
 640         } else if (dev->class && dev->class->pm) {
 641                 pm_dev_dbg(dev, state, "completing class ");
 642                 if (dev->class->pm->complete)
 643                         dev->class->pm->complete(dev);
 644         } else if (dev->bus && dev->bus->pm) {
 645                 pm_dev_dbg(dev, state, "completing ");
 646                 if (dev->bus->pm->complete)
 647                         dev->bus->pm->complete(dev);
 648         }
 649
 650         device_unlock(dev);
 651 }
 652
 653 /**
 654  * dpm_complete - Complete a PM transition for all non-sysdev devices.
 655  * @state: PM transition of the system being carried out.
 656  *
 657  * Execute the ->complete() callbacks for all devices whose PM status is not
 658  * DPM_ON (this allows new devices to be registered).
 659  */
 660 static void dpm_complete(pm_message_t state)
 661 {
 662         struct list_head list;
 663
 664         INIT_LIST_HEAD(&list);
 665         mutex_lock(&dpm_list_mtx);
 666         while (!list_empty(&dpm_prepared_list)) {
 667                 struct device *dev = to_device(dpm_prepared_list.prev);
 668
 669                 get_device(dev);
 670                 dev->power.in_suspend = false;
 671                 list_move(&dev->power.entry, &list);
 672                 mutex_unlock(&dpm_list_mtx);
 673
 674                 device_complete(dev, state);
 675
 676                 mutex_lock(&dpm_list_mtx);
 677                 put_device(dev);
 678         }
 679         list_splice(&list, &dpm_list);
 680         mutex_unlock(&dpm_list_mtx);
 681 }
 682
 683 /**
 684  * dpm_resume_end - Execute "resume" callbacks and complete system transition.
 685  * @state: PM transition of the system being carried out.
 686  *
 687  * Execute "resume" callbacks for all devices and complete the PM transition of
 688  * the system.
 689  */
 690 void dpm_resume_end(pm_message_t state)
 691 {
 692         might_sleep();
 693         dpm_resume(state);
 694         dpm_complete(state);
 695 }
 696 EXPORT_SYMBOL_GPL(dpm_resume_end);
 697
 698
 699 /*------------------------- Suspend routines -------------------------*/
 700
 701 /**
 702  * resume_event - Return a "resume" message for given "suspend" sleep state.
 703  * @sleep_state: PM message representing a sleep state.
 704  *
 705  * Return a PM message representing the resume event corresponding to given
 706  * sleep state.
 707  */
 708 static pm_message_t resume_event(pm_message_t sleep_state)
 709 {
 710         switch (sleep_state.event) {
 711         case PM_EVENT_SUSPEND:
 712                 return PMSG_RESUME;
 713         case PM_EVENT_FREEZE:
 714         case PM_EVENT_QUIESCE:
 715                 return PMSG_RECOVER;
 716         case PM_EVENT_HIBERNATE:
 717                 return PMSG_RESTORE;
 718         }
 719         return PMSG_ON;
 720 }
 721
 722 /**
 723  * device_suspend_noirq - Execute a "late suspend" callback for given device.
 724  * @dev: Device to handle.
 725  * @state: PM transition of the system being carried out.
 726  *
 727  * The driver of @dev will not receive interrupts while this function is being
 728  * executed.
 729  */
 730 static int device_suspend_noirq(struct device *dev, pm_message_t state)
 731 {
 732         int error;
 733
 734         if (dev->type && dev->type->pm) {
 735                 pm_dev_dbg(dev, state, "LATE type ");
 736                 error = pm_noirq_op(dev, dev->type->pm, state);
 737                 if (error)
 738                         return error;
 739         } else if (dev->class && dev->class->pm) {
 740                 pm_dev_dbg(dev, state, "LATE class ");
 741                 error = pm_noirq_op(dev, dev->class->pm, state);
 742                 if (error)
 743                         return error;
 744         } else if (dev->bus && dev->bus->pm) {
 745                 pm_dev_dbg(dev, state, "LATE ");
 746                 error = pm_noirq_op(dev, dev->bus->pm, state);
 747                 if (error)
 748                         return error;
 749         }
 750
 751         if (dev->pwr_domain) {
 752                 pm_dev_dbg(dev, state, "LATE power domain ");
 753                 pm_noirq_op(dev, &dev->pwr_domain->ops, state);
 754         }
 755
 756         return 0;
 757 }
 758
 759 /**
 760  * dpm_suspend_noirq - Execute "late suspend" callbacks for non-sysdev devices.
 761  * @state: PM transition of the system being carried out.
 762  *
 763  * Prevent device drivers from receiving interrupts and call the "noirq" suspend
 764  * handlers for all non-sysdev devices.
 765  */
 766 int dpm_suspend_noirq(pm_message_t state)
 767 {
 768         ktime_t starttime = ktime_get();
 769         int error = 0;
 770
 771         suspend_device_irqs();
 772         mutex_lock(&dpm_list_mtx);
 773         while (!list_empty(&dpm_suspended_list)) {
 774                 struct device *dev = to_device(dpm_suspended_list.prev);
 775
 776                 get_device(dev);
 777                 mutex_unlock(&dpm_list_mtx);
 778
 779                 error = device_suspend_noirq(dev, state);
 780
 781                 mutex_lock(&dpm_list_mtx);
 782                 if (error) {
 783                         pm_dev_err(dev, state, " late", error);
 784                         put_device(dev);
 785                         break;
 786                 }
 787                 if (!list_empty(&dev->power.entry))
 788                         list_move(&dev->power.entry, &dpm_noirq_list);
 789                 put_device(dev);
 790         }
 791         mutex_unlock(&dpm_list_mtx);
 792         if (error)
 793                 dpm_resume_noirq(resume_event(state));
 794         else
 795                 dpm_show_time(starttime, state, "late");
 796         return error;
 797 }
 798 EXPORT_SYMBOL_GPL(dpm_suspend_noirq);
 799
 800 /**
 801  * legacy_suspend - Execute a legacy (bus or class) suspend callback for device.
 802  * @dev: Device to suspend.
 803  * @state: PM transition of the system being carried out.
 804  * @cb: Suspend callback to execute.
 805  */
 806 static int legacy_suspend(struct device *dev, pm_message_t state,
 807                           int (*cb)(struct device *dev, pm_message_t state))
 808 {
 809         int error;
 810         ktime_t calltime;
 811
 812         calltime = initcall_debug_start(dev);
 813
 814         error = cb(dev, state);
 815         suspend_report_result(cb, error);
 816
 817         initcall_debug_report(dev, calltime, error);
 818
 819         return error;
 820 }
 821
 822 /**
 823  * device_suspend - Execute "suspend" callbacks for given device.
 824  * @dev: Device to handle.
 825  * @state: PM transition of the system being carried out.
 826  * @async: If true, the device is being suspended asynchronously.
 827  */
 828 static int __device_suspend(struct device *dev, pm_message_t state, bool async)
 829 {
 830         int error = 0;
 831
 832         dpm_wait_for_children(dev, async);
 833         device_lock(dev);
 834
 835         if (async_error)
 836                 goto End;
 837
 838         if (pm_wakeup_pending()) {
 839                 async_error = -EBUSY;
 840                 goto End;
 841         }
 842
 843         if (dev->type && dev->type->pm) {
 844                 pm_dev_dbg(dev, state, "type ");
 845                 error = pm_op(dev, dev->type->pm, state);
 846                 goto Domain;
 847         }
 848
 849         if (dev->class) {
 850                 if (dev->class->pm) {
 851                         pm_dev_dbg(dev, state, "class ");
 852                         error = pm_op(dev, dev->class->pm, state);
 853                         goto Domain;
 854                 } else if (dev->class->suspend) {
 855                         pm_dev_dbg(dev, state, "legacy class ");
 856                         error = legacy_suspend(dev, state, dev->class->suspend);
 857                         goto Domain;
 858                 }
 859         }
 860
 861         if (dev->bus) {
 862                 if (dev->bus->pm) {
 863                         pm_dev_dbg(dev, state, "");
 864                         error = pm_op(dev, dev->bus->pm, state);
 865                 } else if (dev->bus->suspend) {
 866                         pm_dev_dbg(dev, state, "legacy ");
 867                         error = legacy_suspend(dev, state, dev->bus->suspend);
 868                 }
 869         }
 870
 871  Domain:
 872         if (!error && dev->pwr_domain) {
 873                 pm_dev_dbg(dev, state, "power domain ");
 874                 pm_op(dev, &dev->pwr_domain->ops, state);
 875         }
 876
 877  End:
 878         device_unlock(dev);
 879         complete_all(&dev->power.completion);
 880
 881         if (error)
 882                 async_error = error;
 883
 884         return error;
 885 }
 886
 887 static void async_suspend(void *data, async_cookie_t cookie)
 888 {
 889         struct device *dev = (struct device *)data;
 890         int error;
 891
 892         error = __device_suspend(dev, pm_transition, true);
 893         if (error)
 894                 pm_dev_err(dev, pm_transition, " async", error);
 895
 896         put_device(dev);
 897 }
 898
 899 static int device_suspend(struct device *dev)
 900 {
 901         INIT_COMPLETION(dev->power.completion);
 902
 903         if (pm_async_enabled && dev->power.async_suspend) {
 904                 get_device(dev);
 905                 async_schedule(async_suspend, dev);
 906                 return 0;
 907         }
 908
 909         return __device_suspend(dev, pm_transition, false);
 910 }
 911
 912 /**
 913  * dpm_suspend - Execute "suspend" callbacks for all non-sysdev devices.
 914  * @state: PM transition of the system being carried out.
 915  */
 916 static int dpm_suspend(pm_message_t state)
 917 {
 918         ktime_t starttime = ktime_get();
 919         int error = 0;
 920
 921         mutex_lock(&dpm_list_mtx);
 922         pm_transition = state;
 923         async_error = 0;
 924         while (!list_empty(&dpm_prepared_list)) {
 925                 struct device *dev = to_device(dpm_prepared_list.prev);
 926
 927                 get_device(dev);
 928                 mutex_unlock(&dpm_list_mtx);
 929
 930                 error = device_suspend(dev);
 931
 932                 mutex_lock(&dpm_list_mtx);
 933                 if (error) {
 934                         pm_dev_err(dev, state, "", error);
 935                         put_device(dev);
 936                         break;
 937                 }
 938                 if (!list_empty(&dev->power.entry))
 939                         list_move(&dev->power.entry, &dpm_suspended_list);
 940                 put_device(dev);
 941                 if (async_error)
 942                         break;
 943         }
 944         mutex_unlock(&dpm_list_mtx);
 945         async_synchronize_full();
 946         if (!error)
 947                 error = async_error;
 948         if (!error)
 949                 dpm_show_time(starttime, state, NULL);
 950         return error;
 951 }
 952
 953 /**
 954  * device_prepare - Prepare a device for system power transition.
 955  * @dev: Device to handle.
 956  * @state: PM transition of the system being carried out.
 957  *
 958  * Execute the ->prepare() callback(s) for given device.  No new children of the
 959  * device may be registered after this function has returned.
 960  */
 961 static int device_prepare(struct device *dev, pm_message_t state)
 962 {
 963         int error = 0;
 964
 965         device_lock(dev);
 966
 967         if (dev->type && dev->type->pm) {
 968                 pm_dev_dbg(dev, state, "preparing type ");
 969                 if (dev->type->pm->prepare)
 970                         error = dev->type->pm->prepare(dev);
 971                 suspend_report_result(dev->type->pm->prepare, error);
 972                 if (error)
 973                         goto End;
 974         } else if (dev->class && dev->class->pm) {
 975                 pm_dev_dbg(dev, state, "preparing class ");
 976                 if (dev->class->pm->prepare)
 977                         error = dev->class->pm->prepare(dev);
 978                 suspend_report_result(dev->class->pm->prepare, error);
 979                 if (error)
 980                         goto End;
 981         } else if (dev->bus && dev->bus->pm) {
 982                 pm_dev_dbg(dev, state, "preparing ");
 983                 if (dev->bus->pm->prepare)
 984                         error = dev->bus->pm->prepare(dev);
 985                 suspend_report_result(dev->bus->pm->prepare, error);
 986                 if (error)
 987                         goto End;
 988         }
 989
 990         if (dev->pwr_domain && dev->pwr_domain->ops.prepare) {
 991                 pm_dev_dbg(dev, state, "preparing power domain ");
 992                 dev->pwr_domain->ops.prepare(dev);
 993         }
 994
 995  End:
 996         device_unlock(dev);
 997
 998         return error;
 999 }
1000
1001 /**
1002  * dpm_prepare - Prepare all non-sysdev devices for a system PM transition.
1003  * @state: PM transition of the system being carried out.
1004  *
1005  * Execute the ->prepare() callback(s) for all devices.
1006  */
1007 static int dpm_prepare(pm_message_t state)
1008 {
1009         int error = 0;
1010
1011         mutex_lock(&dpm_list_mtx);
1012         while (!list_empty(&dpm_list)) {
1013                 struct device *dev = to_device(dpm_list.next);
1014
1015                 get_device(dev);
1016                 mutex_unlock(&dpm_list_mtx);
1017
1018                 pm_runtime_get_noresume(dev);
1019                 if (pm_runtime_barrier(dev) && device_may_wakeup(dev))
1020                         pm_wakeup_event(dev, 0);
1021
1022                 pm_runtime_put_sync(dev);
1023                 error = pm_wakeup_pending() ?
1024                                 -EBUSY : device_prepare(dev, state);
1025
1026                 mutex_lock(&dpm_list_mtx);
1027                 if (error) {
1028                         if (error == -EAGAIN) {
1029                                 put_device(dev);
1030                                 error = 0;
1031                                 continue;
1032                         }
1033                         printk(KERN_INFO "PM: Device %s not prepared "
1034                                 "for power transition: code %d\n",
1035                                 dev_name(dev), error);
1036                         put_device(dev);
1037                         break;
1038                 }
1039                 dev->power.in_suspend = true;
1040                 if (!list_empty(&dev->power.entry))
1041                         list_move_tail(&dev->power.entry, &dpm_prepared_list);
1042                 put_device(dev);
1043         }
1044         mutex_unlock(&dpm_list_mtx);
1045         return error;
1046 }
1047
1048 /**
1049  * dpm_suspend_start - Prepare devices for PM transition and suspend them.
1050  * @state: PM transition of the system being carried out.
1051  *
1052  * Prepare all non-sysdev devices for system PM transition and execute "suspend"
1053  * callbacks for them.
1054  */
1055 int dpm_suspend_start(pm_message_t state)
1056 {
1057         int error;
1058
1059         might_sleep();
1060         error = dpm_prepare(state);
1061         if (!error)
1062                 error = dpm_suspend(state);
1063         return error;
1064 }
1065 EXPORT_SYMBOL_GPL(dpm_suspend_start);
1066
1067 void __suspend_report_result(const char *function, void *fn, int ret)
1068 {
1069         if (ret)
1070                 printk(KERN_ERR "%s(): %pF returns %d\n", function, fn, ret);
1071 }
1072 EXPORT_SYMBOL_GPL(__suspend_report_result);
1073
1074 /**
1075  * device_pm_wait_for_dev - Wait for suspend/resume of a device to complete.
1076  * @dev: Device to wait for.
1077  * @subordinate: Device that needs to wait for @dev.
1078  */
1079 int device_pm_wait_for_dev(struct device *subordinate, struct device *dev)
1080 {
1081         dpm_wait(dev, subordinate->power.async_suspend);
1082         return async_error;
1083 }
1084 EXPORT_SYMBOL_GPL(device_pm_wait_for_dev);