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.is_prepared = false;
  61         dev->power.is_suspended = false;
  62         init_completion(&dev->power.completion);
  63         complete_all(&dev->power.completion);
  64         dev->power.wakeup = NULL;
  65         spin_lock_init(&dev->power.lock);
  66         pm_runtime_init(dev);
  67         INIT_LIST_HEAD(&dev->power.entry);
  68 }
  69
  70 /**
  71  * device_pm_lock - Lock the list of active devices used by the PM core.
  72  */
  73 void device_pm_lock(void)
  74 {
  75         mutex_lock(&dpm_list_mtx);
  76 }
  77
  78 /**
  79  * device_pm_unlock - Unlock the list of active devices used by the PM core.
  80  */
  81 void device_pm_unlock(void)
  82 {
  83         mutex_unlock(&dpm_list_mtx);
  84 }
  85
  86 /**
  87  * device_pm_add - Add a device to the PM core's list of active devices.
  88  * @dev: Device to add to the list.
  89  */
  90 void device_pm_add(struct device *dev)
  91 {
  92         pr_debug("PM: Adding info for %s:%s\n",
  93                  dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
  94         mutex_lock(&dpm_list_mtx);
  95         if (dev->parent && dev->parent->power.is_prepared)
  96                 dev_warn(dev, "parent %s should not be sleeping\n",
  97                         dev_name(dev->parent));
  98         list_add_tail(&dev->power.entry, &dpm_list);
  99         mutex_unlock(&dpm_list_mtx);
 100 }
 101
 102 /**
 103  * device_pm_remove - Remove a device from the PM core's list of active devices.
 104  * @dev: Device to be removed from the list.
 105  */
 106 void device_pm_remove(struct device *dev)
 107 {
 108         pr_debug("PM: Removing info for %s:%s\n",
 109                  dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
 110         complete_all(&dev->power.completion);
 111         mutex_lock(&dpm_list_mtx);
 112         list_del_init(&dev->power.entry);
 113         mutex_unlock(&dpm_list_mtx);
 114         device_wakeup_disable(dev);
 115         pm_runtime_remove(dev);
 116 }
 117
 118 /**
 119  * device_pm_move_before - Move device in the PM core's list of active devices.
 120  * @deva: Device to move in dpm_list.
 121  * @devb: Device @deva should come before.
 122  */
 123 void device_pm_move_before(struct device *deva, struct device *devb)
 124 {
 125         pr_debug("PM: Moving %s:%s before %s:%s\n",
 126                  deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
 127                  devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
 128         /* Delete deva from dpm_list and reinsert before devb. */
 129         list_move_tail(&deva->power.entry, &devb->power.entry);
 130 }
 131
 132 /**
 133  * device_pm_move_after - Move device in the PM core's list of active devices.
 134  * @deva: Device to move in dpm_list.
 135  * @devb: Device @deva should come after.
 136  */
 137 void device_pm_move_after(struct device *deva, struct device *devb)
 138 {
 139         pr_debug("PM: Moving %s:%s after %s:%s\n",
 140                  deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
 141                  devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
 142         /* Delete deva from dpm_list and reinsert after devb. */
 143         list_move(&deva->power.entry, &devb->power.entry);
 144 }
 145
 146 /**
 147  * device_pm_move_last - Move device to end of the PM core's list of devices.
 148  * @dev: Device to move in dpm_list.
 149  */
 150 void device_pm_move_last(struct device *dev)
 151 {
 152         pr_debug("PM: Moving %s:%s to end of list\n",
 153                  dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
 154         list_move_tail(&dev->power.entry, &dpm_list);
 155 }
 156
 157 static ktime_t initcall_debug_start(struct device *dev)
 158 {
 159         ktime_t calltime = ktime_set(0, 0);
 160
 161         if (initcall_debug) {
 162                 pr_info("calling  %s+ @ %i\n",
 163                                 dev_name(dev), task_pid_nr(current));
 164                 calltime = ktime_get();
 165         }
 166
 167         return calltime;
 168 }
 169
 170 static void initcall_debug_report(struct device *dev, ktime_t calltime,
 171                                   int error)
 172 {
 173         ktime_t delta, rettime;
 174
 175         if (initcall_debug) {
 176                 rettime = ktime_get();
 177                 delta = ktime_sub(rettime, calltime);
 178                 pr_info("call %s+ returned %d after %Ld usecs\n", dev_name(dev),
 179                         error, (unsigned long long)ktime_to_ns(delta) >> 10);
 180         }
 181 }
 182
 183 /**
 184  * dpm_wait - Wait for a PM operation to complete.
 185  * @dev: Device to wait for.
 186  * @async: If unset, wait only if the device's power.async_suspend flag is set.
 187  */
 188 static void dpm_wait(struct device *dev, bool async)
 189 {
 190         if (!dev)
 191                 return;
 192
 193         if (async || (pm_async_enabled && dev->power.async_suspend))
 194                 wait_for_completion(&dev->power.completion);
 195 }
 196
 197 static int dpm_wait_fn(struct device *dev, void *async_ptr)
 198 {
 199         dpm_wait(dev, *((bool *)async_ptr));
 200         return 0;
 201 }
 202
 203 static void dpm_wait_for_children(struct device *dev, bool async)
 204 {
 205        device_for_each_child(dev, &async, dpm_wait_fn);
 206 }
 207
 208 /**
 209  * pm_op - Execute the PM operation appropriate for given PM event.
 210  * @dev: Device to handle.
 211  * @ops: PM operations to choose from.
 212  * @state: PM transition of the system being carried out.
 213  */
 214 static int pm_op(struct device *dev,
 215                  const struct dev_pm_ops *ops,
 216                  pm_message_t state)
 217 {
 218         int error = 0;
 219         ktime_t calltime;
 220
 221         calltime = initcall_debug_start(dev);
 222
 223         switch (state.event) {
 224 #ifdef CONFIG_SUSPEND
 225         case PM_EVENT_SUSPEND:
 226                 if (ops->suspend) {
 227                         error = ops->suspend(dev);
 228                         suspend_report_result(ops->suspend, error);
 229                 }
 230                 break;
 231         case PM_EVENT_RESUME:
 232                 if (ops->resume) {
 233                         error = ops->resume(dev);
 234                         suspend_report_result(ops->resume, error);
 235                 }
 236                 break;
 237 #endif /* CONFIG_SUSPEND */
 238 #ifdef CONFIG_HIBERNATE_CALLBACKS
 239         case PM_EVENT_FREEZE:
 240         case PM_EVENT_QUIESCE:
 241                 if (ops->freeze) {
 242                         error = ops->freeze(dev);
 243                         suspend_report_result(ops->freeze, error);
 244                 }
 245                 break;
 246         case PM_EVENT_HIBERNATE:
 247                 if (ops->poweroff) {
 248                         error = ops->poweroff(dev);
 249                         suspend_report_result(ops->poweroff, error);
 250                 }
 251                 break;
 252         case PM_EVENT_THAW:
 253         case PM_EVENT_RECOVER:
 254                 if (ops->thaw) {
 255                         error = ops->thaw(dev);
 256                         suspend_report_result(ops->thaw, error);
 257                 }
 258                 break;
 259         case PM_EVENT_RESTORE:
 260                 if (ops->restore) {
 261                         error = ops->restore(dev);
 262                         suspend_report_result(ops->restore, error);
 263                 }
 264                 break;
 265 #endif /* CONFIG_HIBERNATE_CALLBACKS */
 266         default:
 267                 error = -EINVAL;
 268         }
 269
 270         initcall_debug_report(dev, calltime, error);
 271
 272         return error;
 273 }
 274
 275 /**
 276  * pm_noirq_op - Execute the PM operation appropriate for given PM event.
 277  * @dev: Device to handle.
 278  * @ops: PM operations to choose from.
 279  * @state: PM transition of the system being carried out.
 280  *
 281  * The driver of @dev will not receive interrupts while this function is being
 282  * executed.
 283  */
 284 static int pm_noirq_op(struct device *dev,
 285                         const struct dev_pm_ops *ops,
 286                         pm_message_t state)
 287 {
 288         int error = 0;
 289         ktime_t calltime = ktime_set(0, 0), delta, rettime;
 290
 291         if (initcall_debug) {
 292                 pr_info("calling  %s+ @ %i, parent: %s\n",
 293                                 dev_name(dev), task_pid_nr(current),
 294                                 dev->parent ? dev_name(dev->parent) : "none");
 295                 calltime = ktime_get();
 296         }
 297
 298         switch (state.event) {
 299 #ifdef CONFIG_SUSPEND
 300         case PM_EVENT_SUSPEND:
 301                 if (ops->suspend_noirq) {
 302                         error = ops->suspend_noirq(dev);
 303                         suspend_report_result(ops->suspend_noirq, error);
 304                 }
 305                 break;
 306         case PM_EVENT_RESUME:
 307                 if (ops->resume_noirq) {
 308                         error = ops->resume_noirq(dev);
 309                         suspend_report_result(ops->resume_noirq, error);
 310                 }
 311                 break;
 312 #endif /* CONFIG_SUSPEND */
 313 #ifdef CONFIG_HIBERNATE_CALLBACKS
 314         case PM_EVENT_FREEZE:
 315         case PM_EVENT_QUIESCE:
 316                 if (ops->freeze_noirq) {
 317                         error = ops->freeze_noirq(dev);
 318                         suspend_report_result(ops->freeze_noirq, error);
 319                 }
 320                 break;
 321         case PM_EVENT_HIBERNATE:
 322                 if (ops->poweroff_noirq) {
 323                         error = ops->poweroff_noirq(dev);
 324                         suspend_report_result(ops->poweroff_noirq, error);
 325                 }
 326                 break;
 327         case PM_EVENT_THAW:
 328         case PM_EVENT_RECOVER:
 329                 if (ops->thaw_noirq) {
 330                         error = ops->thaw_noirq(dev);
 331                         suspend_report_result(ops->thaw_noirq, error);
 332                 }
 333                 break;
 334         case PM_EVENT_RESTORE:
 335                 if (ops->restore_noirq) {
 336                         error = ops->restore_noirq(dev);
 337                         suspend_report_result(ops->restore_noirq, error);
 338                 }
 339                 break;
 340 #endif /* CONFIG_HIBERNATE_CALLBACKS */
 341         default:
 342                 error = -EINVAL;
 343         }
 344
 345         if (initcall_debug) {
 346                 rettime = ktime_get();
 347                 delta = ktime_sub(rettime, calltime);
 348                 printk("initcall %s_i+ returned %d after %Ld usecs\n",
 349                         dev_name(dev), error,
 350                         (unsigned long long)ktime_to_ns(delta) >> 10);
 351         }
 352
 353         return error;
 354 }
 355
 356 static char *pm_verb(int event)
 357 {
 358         switch (event) {
 359         case PM_EVENT_SUSPEND:
 360                 return "suspend";
 361         case PM_EVENT_RESUME:
 362                 return "resume";
 363         case PM_EVENT_FREEZE:
 364                 return "freeze";
 365         case PM_EVENT_QUIESCE:
 366                 return "quiesce";
 367         case PM_EVENT_HIBERNATE:
 368                 return "hibernate";
 369         case PM_EVENT_THAW:
 370                 return "thaw";
 371         case PM_EVENT_RESTORE:
 372                 return "restore";
 373         case PM_EVENT_RECOVER:
 374                 return "recover";
 375         default:
 376                 return "(unknown PM event)";
 377         }
 378 }
 379
 380 static void pm_dev_dbg(struct device *dev, pm_message_t state, char *info)
 381 {
 382         dev_dbg(dev, "%s%s%s\n", info, pm_verb(state.event),
 383                 ((state.event & PM_EVENT_SLEEP) && device_may_wakeup(dev)) ?
 384                 ", may wakeup" : "");
 385 }
 386
 387 static void pm_dev_err(struct device *dev, pm_message_t state, char *info,
 388                         int error)
 389 {
 390         printk(KERN_ERR "PM: Device %s failed to %s%s: error %d\n",
 391                 dev_name(dev), pm_verb(state.event), info, error);
 392 }
 393
 394 static void dpm_show_time(ktime_t starttime, pm_message_t state, char *info)
 395 {
 396         ktime_t calltime;
 397         u64 usecs64;
 398         int usecs;
 399
 400         calltime = ktime_get();
 401         usecs64 = ktime_to_ns(ktime_sub(calltime, starttime));
 402         do_div(usecs64, NSEC_PER_USEC);
 403         usecs = usecs64;
 404         if (usecs == 0)
 405                 usecs = 1;
 406         pr_info("PM: %s%s%s of devices complete after %ld.%03ld msecs\n",
 407                 info ?: "", info ? " " : "", pm_verb(state.event),
 408                 usecs / USEC_PER_MSEC, usecs % USEC_PER_MSEC);
 409 }
 410
 411 /*------------------------- Resume routines -------------------------*/
 412
 413 /**
 414  * device_resume_noirq - Execute an "early resume" callback for given device.
 415  * @dev: Device to handle.
 416  * @state: PM transition of the system being carried out.
 417  *
 418  * The driver of @dev will not receive interrupts while this function is being
 419  * executed.
 420  */
 421 static int device_resume_noirq(struct device *dev, pm_message_t state)
 422 {
 423         int error = 0;
 424
 425         TRACE_DEVICE(dev);
 426         TRACE_RESUME(0);
 427
 428         if (dev->pwr_domain) {
 429                 pm_dev_dbg(dev, state, "EARLY power domain ");
 430                 error = pm_noirq_op(dev, &dev->pwr_domain->ops, state);
 431         } else 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         /*
 516          * This is a fib.  But we'll allow new children to be added below
 517          * a resumed device, even if the device hasn't been completed yet.
 518          */
 519         dev->power.is_prepared = false;
 520
 521         if (!dev->power.is_suspended)
 522                 goto Unlock;
 523
 524         if (dev->pwr_domain) {
 525                 pm_dev_dbg(dev, state, "power domain ");
 526                 error = pm_op(dev, &dev->pwr_domain->ops, state);
 527                 goto End;
 528         }
 529
 530         if (dev->type && dev->type->pm) {
 531                 pm_dev_dbg(dev, state, "type ");
 532                 error = pm_op(dev, dev->type->pm, state);
 533                 goto End;
 534         }
 535
 536         if (dev->class) {
 537                 if (dev->class->pm) {
 538                         pm_dev_dbg(dev, state, "class ");
 539                         error = pm_op(dev, dev->class->pm, state);
 540                         goto End;
 541                 } else if (dev->class->resume) {
 542                         pm_dev_dbg(dev, state, "legacy class ");
 543                         error = legacy_resume(dev, dev->class->resume);
 544                         goto End;
 545                 }
 546         }
 547
 548         if (dev->bus) {
 549                 if (dev->bus->pm) {
 550                         pm_dev_dbg(dev, state, "");
 551                         error = pm_op(dev, dev->bus->pm, state);
 552                 } else if (dev->bus->resume) {
 553                         pm_dev_dbg(dev, state, "legacy ");
 554                         error = legacy_resume(dev, dev->bus->resume);
 555                 }
 556         }
 557
 558  End:
 559         dev->power.is_suspended = false;
 560
 561  Unlock:
 562         device_unlock(dev);
 563         complete_all(&dev->power.completion);
 564
 565         TRACE_RESUME(error);
 566         return error;
 567 }
 568
 569 static void async_resume(void *data, async_cookie_t cookie)
 570 {
 571         struct device *dev = (struct device *)data;
 572         int error;
 573
 574         error = device_resume(dev, pm_transition, true);
 575         if (error)
 576                 pm_dev_err(dev, pm_transition, " async", error);
 577         put_device(dev);
 578 }
 579
 580 static bool is_async(struct device *dev)
 581 {
 582         return dev->power.async_suspend && pm_async_enabled
 583                 && !pm_trace_is_enabled();
 584 }
 585
 586 /**
 587  * dpm_resume - Execute "resume" callbacks for non-sysdev devices.
 588  * @state: PM transition of the system being carried out.
 589  *
 590  * Execute the appropriate "resume" callback for all devices whose status
 591  * indicates that they are suspended.
 592  */
 593 void dpm_resume(pm_message_t state)
 594 {
 595         struct device *dev;
 596         ktime_t starttime = ktime_get();
 597
 598         might_sleep();
 599
 600         mutex_lock(&dpm_list_mtx);
 601         pm_transition = state;
 602         async_error = 0;
 603
 604         list_for_each_entry(dev, &dpm_suspended_list, power.entry) {
 605                 INIT_COMPLETION(dev->power.completion);
 606                 if (is_async(dev)) {
 607                         get_device(dev);
 608                         async_schedule(async_resume, dev);
 609                 }
 610         }
 611
 612         while (!list_empty(&dpm_suspended_list)) {
 613                 dev = to_device(dpm_suspended_list.next);
 614                 get_device(dev);
 615                 if (!is_async(dev)) {
 616                         int error;
 617
 618                         mutex_unlock(&dpm_list_mtx);
 619
 620                         error = device_resume(dev, state, false);
 621                         if (error)
 622                                 pm_dev_err(dev, state, "", error);
 623
 624                         mutex_lock(&dpm_list_mtx);
 625                 }
 626                 if (!list_empty(&dev->power.entry))
 627                         list_move_tail(&dev->power.entry, &dpm_prepared_list);
 628                 put_device(dev);
 629         }
 630         mutex_unlock(&dpm_list_mtx);
 631         async_synchronize_full();
 632         dpm_show_time(starttime, state, NULL);
 633 }
 634
 635 /**
 636  * device_complete - Complete a PM transition for given device.
 637  * @dev: Device to handle.
 638  * @state: PM transition of the system being carried out.
 639  */
 640 static void device_complete(struct device *dev, pm_message_t state)
 641 {
 642         device_lock(dev);
 643
 644         if (dev->pwr_domain) {
 645                 pm_dev_dbg(dev, state, "completing power domain ");
 646                 if (dev->pwr_domain->ops.complete)
 647                         dev->pwr_domain->ops.complete(dev);
 648         } else if (dev->type && dev->type->pm) {
 649                 pm_dev_dbg(dev, state, "completing type ");
 650                 if (dev->type->pm->complete)
 651                         dev->type->pm->complete(dev);
 652         } else if (dev->class && dev->class->pm) {
 653                 pm_dev_dbg(dev, state, "completing class ");
 654                 if (dev->class->pm->complete)
 655                         dev->class->pm->complete(dev);
 656         } else if (dev->bus && dev->bus->pm) {
 657                 pm_dev_dbg(dev, state, "completing ");
 658                 if (dev->bus->pm->complete)
 659                         dev->bus->pm->complete(dev);
 660         }
 661
 662         device_unlock(dev);
 663 }
 664
 665 /**
 666  * dpm_complete - Complete a PM transition for all non-sysdev devices.
 667  * @state: PM transition of the system being carried out.
 668  *
 669  * Execute the ->complete() callbacks for all devices whose PM status is not
 670  * DPM_ON (this allows new devices to be registered).
 671  */
 672 void dpm_complete(pm_message_t state)
 673 {
 674         struct list_head list;
 675
 676         might_sleep();
 677
 678         INIT_LIST_HEAD(&list);
 679         mutex_lock(&dpm_list_mtx);
 680         while (!list_empty(&dpm_prepared_list)) {
 681                 struct device *dev = to_device(dpm_prepared_list.prev);
 682
 683                 get_device(dev);
 684                 dev->power.is_prepared = false;
 685                 list_move(&dev->power.entry, &list);
 686                 mutex_unlock(&dpm_list_mtx);
 687
 688                 device_complete(dev, state);
 689
 690                 mutex_lock(&dpm_list_mtx);
 691                 put_device(dev);
 692         }
 693         list_splice(&list, &dpm_list);
 694         mutex_unlock(&dpm_list_mtx);
 695 }
 696
 697 /**
 698  * dpm_resume_end - Execute "resume" callbacks and complete system transition.
 699  * @state: PM transition of the system being carried out.
 700  *
 701  * Execute "resume" callbacks for all devices and complete the PM transition of
 702  * the system.
 703  */
 704 void dpm_resume_end(pm_message_t state)
 705 {
 706         dpm_resume(state);
 707         dpm_complete(state);
 708 }
 709 EXPORT_SYMBOL_GPL(dpm_resume_end);
 710
 711
 712 /*------------------------- Suspend routines -------------------------*/
 713
 714 /**
 715  * resume_event - Return a "resume" message for given "suspend" sleep state.
 716  * @sleep_state: PM message representing a sleep state.
 717  *
 718  * Return a PM message representing the resume event corresponding to given
 719  * sleep state.
 720  */
 721 static pm_message_t resume_event(pm_message_t sleep_state)
 722 {
 723         switch (sleep_state.event) {
 724         case PM_EVENT_SUSPEND:
 725                 return PMSG_RESUME;
 726         case PM_EVENT_FREEZE:
 727         case PM_EVENT_QUIESCE:
 728                 return PMSG_RECOVER;
 729         case PM_EVENT_HIBERNATE:
 730                 return PMSG_RESTORE;
 731         }
 732         return PMSG_ON;
 733 }
 734
 735 /**
 736  * device_suspend_noirq - Execute a "late suspend" callback for given device.
 737  * @dev: Device to handle.
 738  * @state: PM transition of the system being carried out.
 739  *
 740  * The driver of @dev will not receive interrupts while this function is being
 741  * executed.
 742  */
 743 static int device_suspend_noirq(struct device *dev, pm_message_t state)
 744 {
 745         int error;
 746
 747         if (dev->pwr_domain) {
 748                 pm_dev_dbg(dev, state, "LATE power domain ");
 749                 error = pm_noirq_op(dev, &dev->pwr_domain->ops, state);
 750                 if (error)
 751                         return error;
 752         } else if (dev->type && dev->type->pm) {
 753                 pm_dev_dbg(dev, state, "LATE type ");
 754                 error = pm_noirq_op(dev, dev->type->pm, state);
 755                 if (error)
 756                         return error;
 757         } else if (dev->class && dev->class->pm) {
 758                 pm_dev_dbg(dev, state, "LATE class ");
 759                 error = pm_noirq_op(dev, dev->class->pm, state);
 760                 if (error)
 761                         return error;
 762         } else if (dev->bus && dev->bus->pm) {
 763                 pm_dev_dbg(dev, state, "LATE ");
 764                 error = pm_noirq_op(dev, dev->bus->pm, state);
 765                 if (error)
 766                         return error;
 767         }
 768
 769         return 0;
 770 }
 771
 772 /**
 773  * dpm_suspend_noirq - Execute "late suspend" callbacks for non-sysdev devices.
 774  * @state: PM transition of the system being carried out.
 775  *
 776  * Prevent device drivers from receiving interrupts and call the "noirq" suspend
 777  * handlers for all non-sysdev devices.
 778  */
 779 int dpm_suspend_noirq(pm_message_t state)
 780 {
 781         ktime_t starttime = ktime_get();
 782         int error = 0;
 783
 784         suspend_device_irqs();
 785         mutex_lock(&dpm_list_mtx);
 786         while (!list_empty(&dpm_suspended_list)) {
 787                 struct device *dev = to_device(dpm_suspended_list.prev);
 788
 789                 get_device(dev);
 790                 mutex_unlock(&dpm_list_mtx);
 791
 792                 error = device_suspend_noirq(dev, state);
 793
 794                 mutex_lock(&dpm_list_mtx);
 795                 if (error) {
 796                         pm_dev_err(dev, state, " late", error);
 797                         put_device(dev);
 798                         break;
 799                 }
 800                 if (!list_empty(&dev->power.entry))
 801                         list_move(&dev->power.entry, &dpm_noirq_list);
 802                 put_device(dev);
 803         }
 804         mutex_unlock(&dpm_list_mtx);
 805         if (error)
 806                 dpm_resume_noirq(resume_event(state));
 807         else
 808                 dpm_show_time(starttime, state, "late");
 809         return error;
 810 }
 811 EXPORT_SYMBOL_GPL(dpm_suspend_noirq);
 812
 813 /**
 814  * legacy_suspend - Execute a legacy (bus or class) suspend callback for device.
 815  * @dev: Device to suspend.
 816  * @state: PM transition of the system being carried out.
 817  * @cb: Suspend callback to execute.
 818  */
 819 static int legacy_suspend(struct device *dev, pm_message_t state,
 820                           int (*cb)(struct device *dev, pm_message_t state))
 821 {
 822         int error;
 823         ktime_t calltime;
 824
 825         calltime = initcall_debug_start(dev);
 826
 827         error = cb(dev, state);
 828         suspend_report_result(cb, error);
 829
 830         initcall_debug_report(dev, calltime, error);
 831
 832         return error;
 833 }
 834
 835 /**
 836  * device_suspend - Execute "suspend" callbacks for given device.
 837  * @dev: Device to handle.
 838  * @state: PM transition of the system being carried out.
 839  * @async: If true, the device is being suspended asynchronously.
 840  */
 841 static int __device_suspend(struct device *dev, pm_message_t state, bool async)
 842 {
 843         int error = 0;
 844
 845         dpm_wait_for_children(dev, async);
 846         device_lock(dev);
 847
 848         if (async_error)
 849                 goto Unlock;
 850
 851         if (pm_wakeup_pending()) {
 852                 async_error = -EBUSY;
 853                 goto Unlock;
 854         }
 855
 856         if (dev->pwr_domain) {
 857                 pm_dev_dbg(dev, state, "power domain ");
 858                 error = pm_op(dev, &dev->pwr_domain->ops, state);
 859                 goto End;
 860         }
 861
 862         if (dev->type && dev->type->pm) {
 863                 pm_dev_dbg(dev, state, "type ");
 864                 error = pm_op(dev, dev->type->pm, state);
 865                 goto End;
 866         }
 867
 868         if (dev->class) {
 869                 if (dev->class->pm) {
 870                         pm_dev_dbg(dev, state, "class ");
 871                         error = pm_op(dev, dev->class->pm, state);
 872                         goto End;
 873                 } else if (dev->class->suspend) {
 874                         pm_dev_dbg(dev, state, "legacy class ");
 875                         error = legacy_suspend(dev, state, dev->class->suspend);
 876                         goto End;
 877                 }
 878         }
 879
 880         if (dev->bus) {
 881                 if (dev->bus->pm) {
 882                         pm_dev_dbg(dev, state, "");
 883                         error = pm_op(dev, dev->bus->pm, state);
 884                 } else if (dev->bus->suspend) {
 885                         pm_dev_dbg(dev, state, "legacy ");
 886                         error = legacy_suspend(dev, state, dev->bus->suspend);
 887                 }
 888         }
 889
 890  End:
 891         dev->power.is_suspended = !error;
 892
 893  Unlock:
 894         device_unlock(dev);
 895         complete_all(&dev->power.completion);
 896
 897         if (error)
 898                 async_error = error;
 899
 900         return error;
 901 }
 902
 903 static void async_suspend(void *data, async_cookie_t cookie)
 904 {
 905         struct device *dev = (struct device *)data;
 906         int error;
 907
 908         error = __device_suspend(dev, pm_transition, true);
 909         if (error)
 910                 pm_dev_err(dev, pm_transition, " async", error);
 911
 912         put_device(dev);
 913 }
 914
 915 static int device_suspend(struct device *dev)
 916 {
 917         INIT_COMPLETION(dev->power.completion);
 918
 919         if (pm_async_enabled && dev->power.async_suspend) {
 920                 get_device(dev);
 921                 async_schedule(async_suspend, dev);
 922                 return 0;
 923         }
 924
 925         return __device_suspend(dev, pm_transition, false);
 926 }
 927
 928 /**
 929  * dpm_suspend - Execute "suspend" callbacks for all non-sysdev devices.
 930  * @state: PM transition of the system being carried out.
 931  */
 932 int dpm_suspend(pm_message_t state)
 933 {
 934         ktime_t starttime = ktime_get();
 935         int error = 0;
 936
 937         might_sleep();
 938
 939         mutex_lock(&dpm_list_mtx);
 940         pm_transition = state;
 941         async_error = 0;
 942         while (!list_empty(&dpm_prepared_list)) {
 943                 struct device *dev = to_device(dpm_prepared_list.prev);
 944
 945                 get_device(dev);
 946                 mutex_unlock(&dpm_list_mtx);
 947
 948                 error = device_suspend(dev);
 949
 950                 mutex_lock(&dpm_list_mtx);
 951                 if (error) {
 952                         pm_dev_err(dev, state, "", error);
 953                         put_device(dev);
 954                         break;
 955                 }
 956                 if (!list_empty(&dev->power.entry))
 957                         list_move(&dev->power.entry, &dpm_suspended_list);
 958                 put_device(dev);
 959                 if (async_error)
 960                         break;
 961         }
 962         mutex_unlock(&dpm_list_mtx);
 963         async_synchronize_full();
 964         if (!error)
 965                 error = async_error;
 966         if (!error)
 967                 dpm_show_time(starttime, state, NULL);
 968         return error;
 969 }
 970
 971 /**
 972  * device_prepare - Prepare a device for system power transition.
 973  * @dev: Device to handle.
 974  * @state: PM transition of the system being carried out.
 975  *
 976  * Execute the ->prepare() callback(s) for given device.  No new children of the
 977  * device may be registered after this function has returned.
 978  */
 979 static int device_prepare(struct device *dev, pm_message_t state)
 980 {
 981         int error = 0;
 982
 983         device_lock(dev);
 984
 985         if (dev->pwr_domain) {
 986                 pm_dev_dbg(dev, state, "preparing power domain ");
 987                 if (dev->pwr_domain->ops.prepare)
 988                         error = dev->pwr_domain->ops.prepare(dev);
 989                 suspend_report_result(dev->pwr_domain->ops.prepare, error);
 990                 if (error)
 991                         goto End;
 992         } else if (dev->type && dev->type->pm) {
 993                 pm_dev_dbg(dev, state, "preparing type ");
 994                 if (dev->type->pm->prepare)
 995                         error = dev->type->pm->prepare(dev);
 996                 suspend_report_result(dev->type->pm->prepare, error);
 997                 if (error)
 998                         goto End;
 999         } else if (dev->class && dev->class->pm) {
1000                 pm_dev_dbg(dev, state, "preparing class ");
1001                 if (dev->class->pm->prepare)
1002                         error = dev->class->pm->prepare(dev);
1003                 suspend_report_result(dev->class->pm->prepare, error);
1004                 if (error)
1005                         goto End;
1006         } else if (dev->bus && dev->bus->pm) {
1007                 pm_dev_dbg(dev, state, "preparing ");
1008                 if (dev->bus->pm->prepare)
1009                         error = dev->bus->pm->prepare(dev);
1010                 suspend_report_result(dev->bus->pm->prepare, error);
1011         }
1012
1013  End:
1014         device_unlock(dev);
1015
1016         return error;
1017 }
1018
1019 /**
1020  * dpm_prepare - Prepare all non-sysdev devices for a system PM transition.
1021  * @state: PM transition of the system being carried out.
1022  *
1023  * Execute the ->prepare() callback(s) for all devices.
1024  */
1025 int dpm_prepare(pm_message_t state)
1026 {
1027         int error = 0;
1028
1029         might_sleep();
1030
1031         mutex_lock(&dpm_list_mtx);
1032         while (!list_empty(&dpm_list)) {
1033                 struct device *dev = to_device(dpm_list.next);
1034
1035                 get_device(dev);
1036                 mutex_unlock(&dpm_list_mtx);
1037
1038                 pm_runtime_get_noresume(dev);
1039                 if (pm_runtime_barrier(dev) && device_may_wakeup(dev))
1040                         pm_wakeup_event(dev, 0);
1041
1042                 pm_runtime_put_sync(dev);
1043                 error = pm_wakeup_pending() ?
1044                                 -EBUSY : device_prepare(dev, state);
1045
1046                 mutex_lock(&dpm_list_mtx);
1047                 if (error) {
1048                         if (error == -EAGAIN) {
1049                                 put_device(dev);
1050                                 error = 0;
1051                                 continue;
1052                         }
1053                         printk(KERN_INFO "PM: Device %s not prepared "
1054                                 "for power transition: code %d\n",
1055                                 dev_name(dev), error);
1056                         put_device(dev);
1057                         break;
1058                 }
1059                 dev->power.is_prepared = true;
1060                 if (!list_empty(&dev->power.entry))
1061                         list_move_tail(&dev->power.entry, &dpm_prepared_list);
1062                 put_device(dev);
1063         }
1064         mutex_unlock(&dpm_list_mtx);
1065         return error;
1066 }
1067
1068 /**
1069  * dpm_suspend_start - Prepare devices for PM transition and suspend them.
1070  * @state: PM transition of the system being carried out.
1071  *
1072  * Prepare all non-sysdev devices for system PM transition and execute "suspend"
1073  * callbacks for them.
1074  */
1075 int dpm_suspend_start(pm_message_t state)
1076 {
1077         int error;
1078
1079         error = dpm_prepare(state);
1080         if (!error)
1081                 error = dpm_suspend(state);
1082         return error;
1083 }
1084 EXPORT_SYMBOL_GPL(dpm_suspend_start);
1085
1086 void __suspend_report_result(const char *function, void *fn, int ret)
1087 {
1088         if (ret)
1089                 printk(KERN_ERR "%s(): %pF returns %d\n", function, fn, ret);
1090 }
1091 EXPORT_SYMBOL_GPL(__suspend_report_result);
1092
1093 /**
1094  * device_pm_wait_for_dev - Wait for suspend/resume of a device to complete.
1095  * @dev: Device to wait for.
1096  * @subordinate: Device that needs to wait for @dev.
1097  */
1098 int device_pm_wait_for_dev(struct device *subordinate, struct device *dev)
1099 {
1100         dpm_wait(dev, subordinate->power.async_suspend);
1101         return async_error;
1102 }
1103 EXPORT_SYMBOL_GPL(device_pm_wait_for_dev);