/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#include <linux/timer.h>
  31#ifdef CONFIG_PLAT_RK
  32#include <linux/console.h>
  33#endif
  34
  35#include "../base.h"
  36#include "power.h"
  37
  38/*
  39 * The entries in the dpm_list list are in a depth first order, simply
  40 * because children are guaranteed to be discovered after parents, and
  41 * are inserted at the back of the list on discovery.
  42 *
  43 * Since device_pm_add() may be called with a device lock held,
  44 * we must never try to acquire a device lock while holding
  45 * dpm_list_mutex.
  46 */
  47
  48LIST_HEAD(dpm_list);
  49LIST_HEAD(dpm_prepared_list);
  50LIST_HEAD(dpm_suspended_list);
  51LIST_HEAD(dpm_noirq_list);
  52
  53static DEFINE_MUTEX(dpm_list_mtx);
  54static pm_message_t pm_transition;
  55
  56static void dpm_drv_timeout(unsigned long data);
  57struct dpm_drv_wd_data {
  58	struct device *dev;
  59	struct task_struct *tsk;
  60};
  61
  62static int async_error;
  63
  64/**
  65 * device_pm_init - Initialize the PM-related part of a device object.
  66 * @dev: Device object being initialized.
  67 */
  68void device_pm_init(struct device *dev)
  69{
  70	dev->power.is_prepared = false;
  71	dev->power.is_suspended = false;
  72	init_completion(&dev->power.completion);
  73	complete_all(&dev->power.completion);
  74	dev->power.wakeup = NULL;
  75	spin_lock_init(&dev->power.lock);
  76	pm_runtime_init(dev);
  77	INIT_LIST_HEAD(&dev->power.entry);
  78}
  79
  80/**
  81 * device_pm_lock - Lock the list of active devices used by the PM core.
  82 */
  83void device_pm_lock(void)
  84{
  85	mutex_lock(&dpm_list_mtx);
  86}
  87
  88/**
  89 * device_pm_unlock - Unlock the list of active devices used by the PM core.
  90 */
  91void device_pm_unlock(void)
  92{
  93	mutex_unlock(&dpm_list_mtx);
  94}
  95
  96/**
  97 * device_pm_add - Add a device to the PM core's list of active devices.
  98 * @dev: Device to add to the list.
  99 */
 100void device_pm_add(struct device *dev)
 101{
 102	pr_debug("PM: Adding info for %s:%s\n",
 103		 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
 104	mutex_lock(&dpm_list_mtx);
 105	if (dev->parent && dev->parent->power.is_prepared)
 106		dev_warn(dev, "parent %s should not be sleeping\n",
 107			dev_name(dev->parent));
 108	list_add_tail(&dev->power.entry, &dpm_list);
 109	mutex_unlock(&dpm_list_mtx);
 110}
 111
 112/**
 113 * device_pm_remove - Remove a device from the PM core's list of active devices.
 114 * @dev: Device to be removed from the list.
 115 */
 116void device_pm_remove(struct device *dev)
 117{
 118	pr_debug("PM: Removing info for %s:%s\n",
 119		 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
 120	complete_all(&dev->power.completion);
 121	mutex_lock(&dpm_list_mtx);
 122	list_del_init(&dev->power.entry);
 123	mutex_unlock(&dpm_list_mtx);
 124	device_wakeup_disable(dev);
 125	pm_runtime_remove(dev);
 126}
 127
 128/**
 129 * device_pm_move_before - Move device in the PM core's list of active devices.
 130 * @deva: Device to move in dpm_list.
 131 * @devb: Device @deva should come before.
 132 */
 133void device_pm_move_before(struct device *deva, struct device *devb)
 134{
 135	pr_debug("PM: Moving %s:%s before %s:%s\n",
 136		 deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
 137		 devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
 138	/* Delete deva from dpm_list and reinsert before devb. */
 139	list_move_tail(&deva->power.entry, &devb->power.entry);
 140}
 141
 142/**
 143 * device_pm_move_after - Move device in the PM core's list of active devices.
 144 * @deva: Device to move in dpm_list.
 145 * @devb: Device @deva should come after.
 146 */
 147void device_pm_move_after(struct device *deva, struct device *devb)
 148{
 149	pr_debug("PM: Moving %s:%s after %s:%s\n",
 150		 deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
 151		 devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
 152	/* Delete deva from dpm_list and reinsert after devb. */
 153	list_move(&deva->power.entry, &devb->power.entry);
 154}
 155
 156/**
 157 * device_pm_move_last - Move device to end of the PM core's list of devices.
 158 * @dev: Device to move in dpm_list.
 159 */
 160void device_pm_move_last(struct device *dev)
 161{
 162	pr_debug("PM: Moving %s:%s to end of list\n",
 163		 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
 164	list_move_tail(&dev->power.entry, &dpm_list);
 165}
 166
 167static ktime_t initcall_debug_start(struct device *dev)
 168{
 169	ktime_t calltime = ktime_set(0, 0);
 170
 171	if (initcall_debug) {
 172		pr_info("calling  %s+ @ %i\n",
 173				dev_name(dev), task_pid_nr(current));
 174		calltime = ktime_get();
 175	}
 176
 177	return calltime;
 178}
 179
 180static void initcall_debug_report(struct device *dev, ktime_t calltime,
 181				  int error)
 182{
 183	ktime_t delta, rettime;
 184
 185	if (initcall_debug) {
 186		rettime = ktime_get();
 187		delta = ktime_sub(rettime, calltime);
 188		pr_info("call %s+ returned %d after %Ld usecs\n", dev_name(dev),
 189			error, (unsigned long long)ktime_to_ns(delta) >> 10);
 190	}
 191}
 192
 193/**
 194 * dpm_wait - Wait for a PM operation to complete.
 195 * @dev: Device to wait for.
 196 * @async: If unset, wait only if the device's power.async_suspend flag is set.
 197 */
 198static void dpm_wait(struct device *dev, bool async)
 199{
 200	if (!dev)
 201		return;
 202
 203	if (async || (pm_async_enabled && dev->power.async_suspend))
 204		wait_for_completion(&dev->power.completion);
 205}
 206
 207static int dpm_wait_fn(struct device *dev, void *async_ptr)
 208{
 209	dpm_wait(dev, *((bool *)async_ptr));
 210	return 0;
 211}
 212
 213static void dpm_wait_for_children(struct device *dev, bool async)
 214{
 215       device_for_each_child(dev, &async, dpm_wait_fn);
 216}
 217
 218/**
 219 * pm_op - Execute the PM operation appropriate for given PM event.
 220 * @dev: Device to handle.
 221 * @ops: PM operations to choose from.
 222 * @state: PM transition of the system being carried out.
 223 */
 224static int pm_op(struct device *dev,
 225		 const struct dev_pm_ops *ops,
 226		 pm_message_t state)
 227{
 228	int error = 0;
 229	ktime_t calltime;
 230
 231	calltime = initcall_debug_start(dev);
 232
 233	switch (state.event) {
 234#ifdef CONFIG_SUSPEND
 235	case PM_EVENT_SUSPEND:
 236		if (ops->suspend) {
 237			error = ops->suspend(dev);
 238			suspend_report_result(ops->suspend, error);
 239		}
 240		break;
 241	case PM_EVENT_RESUME:
 242		if (ops->resume) {
 243			error = ops->resume(dev);
 244			suspend_report_result(ops->resume, error);
 245		}
 246		break;
 247#endif /* CONFIG_SUSPEND */
 248#ifdef CONFIG_HIBERNATE_CALLBACKS
 249	case PM_EVENT_FREEZE:
 250	case PM_EVENT_QUIESCE:
 251		if (ops->freeze) {
 252			error = ops->freeze(dev);
 253			suspend_report_result(ops->freeze, error);
 254		}
 255		break;
 256	case PM_EVENT_HIBERNATE:
 257		if (ops->poweroff) {
 258			error = ops->poweroff(dev);
 259			suspend_report_result(ops->poweroff, error);
 260		}
 261		break;
 262	case PM_EVENT_THAW:
 263	case PM_EVENT_RECOVER:
 264		if (ops->thaw) {
 265			error = ops->thaw(dev);
 266			suspend_report_result(ops->thaw, error);
 267		}
 268		break;
 269	case PM_EVENT_RESTORE:
 270		if (ops->restore) {
 271			error = ops->restore(dev);
 272			suspend_report_result(ops->restore, error);
 273		}
 274		break;
 275#endif /* CONFIG_HIBERNATE_CALLBACKS */
 276	default:
 277		error = -EINVAL;
 278	}
 279
 280	initcall_debug_report(dev, calltime, error);
 281
 282	return error;
 283}
 284
 285/**
 286 * pm_noirq_op - Execute the PM operation appropriate for given PM event.
 287 * @dev: Device to handle.
 288 * @ops: PM operations to choose from.
 289 * @state: PM transition of the system being carried out.
 290 *
 291 * The driver of @dev will not receive interrupts while this function is being
 292 * executed.
 293 */
 294static int pm_noirq_op(struct device *dev,
 295			const struct dev_pm_ops *ops,
 296			pm_message_t state)
 297{
 298	int error = 0;
 299	ktime_t calltime = ktime_set(0, 0), delta, rettime;
 300
 301	if (initcall_debug) {
 302		pr_info("calling  %s+ @ %i, parent: %s\n",
 303				dev_name(dev), task_pid_nr(current),
 304				dev->parent ? dev_name(dev->parent) : "none");
 305		calltime = ktime_get();
 306	}
 307
 308	switch (state.event) {
 309#ifdef CONFIG_SUSPEND
 310	case PM_EVENT_SUSPEND:
 311		if (ops->suspend_noirq) {
 312			error = ops->suspend_noirq(dev);
 313			suspend_report_result(ops->suspend_noirq, error);
 314		}
 315		break;
 316	case PM_EVENT_RESUME:
 317		if (ops->resume_noirq) {
 318			error = ops->resume_noirq(dev);
 319			suspend_report_result(ops->resume_noirq, error);
 320		}
 321		break;
 322#endif /* CONFIG_SUSPEND */
 323#ifdef CONFIG_HIBERNATE_CALLBACKS
 324	case PM_EVENT_FREEZE:
 325	case PM_EVENT_QUIESCE:
 326		if (ops->freeze_noirq) {
 327			error = ops->freeze_noirq(dev);
 328			suspend_report_result(ops->freeze_noirq, error);
 329		}
 330		break;
 331	case PM_EVENT_HIBERNATE:
 332		if (ops->poweroff_noirq) {
 333			error = ops->poweroff_noirq(dev);
 334			suspend_report_result(ops->poweroff_noirq, error);
 335		}
 336		break;
 337	case PM_EVENT_THAW:
 338	case PM_EVENT_RECOVER:
 339		if (ops->thaw_noirq) {
 340			error = ops->thaw_noirq(dev);
 341			suspend_report_result(ops->thaw_noirq, error);
 342		}
 343		break;
 344	case PM_EVENT_RESTORE:
 345		if (ops->restore_noirq) {
 346			error = ops->restore_noirq(dev);
 347			suspend_report_result(ops->restore_noirq, error);
 348		}
 349		break;
 350#endif /* CONFIG_HIBERNATE_CALLBACKS */
 351	default:
 352		error = -EINVAL;
 353	}
 354
 355	if (initcall_debug) {
 356		rettime = ktime_get();
 357		delta = ktime_sub(rettime, calltime);
 358		printk("initcall %s_i+ returned %d after %Ld usecs\n",
 359			dev_name(dev), error,
 360			(unsigned long long)ktime_to_ns(delta) >> 10);
 361	}
 362
 363	return error;
 364}
 365
 366static char *pm_verb(int event)
 367{
 368	switch (event) {
 369	case PM_EVENT_SUSPEND:
 370		return "suspend";
 371	case PM_EVENT_RESUME:
 372		return "resume";
 373	case PM_EVENT_FREEZE:
 374		return "freeze";
 375	case PM_EVENT_QUIESCE:
 376		return "quiesce";
 377	case PM_EVENT_HIBERNATE:
 378		return "hibernate";
 379	case PM_EVENT_THAW:
 380		return "thaw";
 381	case PM_EVENT_RESTORE:
 382		return "restore";
 383	case PM_EVENT_RECOVER:
 384		return "recover";
 385	default:
 386		return "(unknown PM event)";
 387	}
 388}
 389
 390static void pm_dev_dbg(struct device *dev, pm_message_t state, char *info)
 391{
 392	dev_dbg(dev, "%s%s%s\n", info, pm_verb(state.event),
 393		((state.event & PM_EVENT_SLEEP) && device_may_wakeup(dev)) ?
 394		", may wakeup" : "");
 395}
 396
 397static void pm_dev_err(struct device *dev, pm_message_t state, char *info,
 398			int error)
 399{
 400	printk(KERN_ERR "PM: Device %s failed to %s%s: error %d\n",
 401		dev_name(dev), pm_verb(state.event), info, error);
 402}
 403
 404static void dpm_show_time(ktime_t starttime, pm_message_t state, char *info)
 405{
 406	ktime_t calltime;
 407	u64 usecs64;
 408	int usecs;
 409
 410	calltime = ktime_get();
 411	usecs64 = ktime_to_ns(ktime_sub(calltime, starttime));
 412	do_div(usecs64, NSEC_PER_USEC);
 413	usecs = usecs64;
 414	if (usecs == 0)
 415		usecs = 1;
 416	pr_info("PM: %s%s%s of devices complete after %ld.%03ld msecs\n",
 417		info ?: "", info ? " " : "", pm_verb(state.event),
 418		usecs / USEC_PER_MSEC, usecs % USEC_PER_MSEC);
 419}
 420
 421/*------------------------- Resume routines -------------------------*/
 422
 423/**
 424 * device_resume_noirq - Execute an "early resume" callback for given device.
 425 * @dev: Device to handle.
 426 * @state: PM transition of the system being carried out.
 427 *
 428 * The driver of @dev will not receive interrupts while this function is being
 429 * executed.
 430 */
 431static int device_resume_noirq(struct device *dev, pm_message_t state)
 432{
 433	int error = 0;
 434
 435	TRACE_DEVICE(dev);
 436	TRACE_RESUME(0);
 437
 438	if (dev->pwr_domain) {
 439		pm_dev_dbg(dev, state, "EARLY power domain ");
 440		error = pm_noirq_op(dev, &dev->pwr_domain->ops, state);
 441	} else if (dev->type && dev->type->pm) {
 442		pm_dev_dbg(dev, state, "EARLY type ");
 443		error = pm_noirq_op(dev, dev->type->pm, state);
 444	} else if (dev->class && dev->class->pm) {
 445		pm_dev_dbg(dev, state, "EARLY class ");
 446		error = pm_noirq_op(dev, dev->class->pm, state);
 447	} else if (dev->bus && dev->bus->pm) {
 448		pm_dev_dbg(dev, state, "EARLY ");
 449		error = pm_noirq_op(dev, dev->bus->pm, state);
 450	}
 451
 452	TRACE_RESUME(error);
 453	return error;
 454}
 455
 456/**
 457 * dpm_resume_noirq - Execute "early resume" callbacks for non-sysdev devices.
 458 * @state: PM transition of the system being carried out.
 459 *
 460 * Call the "noirq" resume handlers for all devices marked as DPM_OFF_IRQ and
 461 * enable device drivers to receive interrupts.
 462 */
 463void dpm_resume_noirq(pm_message_t state)
 464{
 465	ktime_t starttime = ktime_get();
 466
 467	mutex_lock(&dpm_list_mtx);
 468	while (!list_empty(&dpm_noirq_list)) {
 469		struct device *dev = to_device(dpm_noirq_list.next);
 470		int error;
 471
 472		get_device(dev);
 473		list_move_tail(&dev->power.entry, &dpm_suspended_list);
 474		mutex_unlock(&dpm_list_mtx);
 475
 476		error = device_resume_noirq(dev, state);
 477		if (error)
 478			pm_dev_err(dev, state, " early", error);
 479
 480		mutex_lock(&dpm_list_mtx);
 481		put_device(dev);
 482	}
 483	mutex_unlock(&dpm_list_mtx);
 484	dpm_show_time(starttime, state, "early");
 485	resume_device_irqs();
 486}
 487EXPORT_SYMBOL_GPL(dpm_resume_noirq);
 488
 489/**
 490 * legacy_resume - Execute a legacy (bus or class) resume callback for device.
 491 * @dev: Device to resume.
 492 * @cb: Resume callback to execute.
 493 */
 494static int legacy_resume(struct device *dev, int (*cb)(struct device *dev))
 495{
 496	int error;
 497	ktime_t calltime;
 498
 499	calltime = initcall_debug_start(dev);
 500
 501	error = cb(dev);
 502	suspend_report_result(cb, error);
 503
 504	initcall_debug_report(dev, calltime, error);
 505
 506	return error;
 507}
 508
 509/**
 510 * device_resume - Execute "resume" callbacks for given device.
 511 * @dev: Device to handle.
 512 * @state: PM transition of the system being carried out.
 513 * @async: If true, the device is being resumed asynchronously.
 514 */
 515static int device_resume(struct device *dev, pm_message_t state, bool async)
 516{
 517	int error = 0;
 518
 519	TRACE_DEVICE(dev);
 520	TRACE_RESUME(0);
 521
 522	dpm_wait(dev->parent, async);
 523	device_lock(dev);
 524
 525	/*
 526	 * This is a fib.  But we'll allow new children to be added below
 527	 * a resumed device, even if the device hasn't been completed yet.
 528	 */
 529	dev->power.is_prepared = false;
 530
 531	if (!dev->power.is_suspended)
 532		goto Unlock;
 533
 534	if (dev->pwr_domain) {
 535		pm_dev_dbg(dev, state, "power domain ");
 536		error = pm_op(dev, &dev->pwr_domain->ops, state);
 537		goto End;
 538	}
 539
 540	if (dev->type && dev->type->pm) {
 541		pm_dev_dbg(dev, state, "type ");
 542		error = pm_op(dev, dev->type->pm, state);
 543		goto End;
 544	}
 545
 546	if (dev->class) {
 547		if (dev->class->pm) {
 548			pm_dev_dbg(dev, state, "class ");
 549			error = pm_op(dev, dev->class->pm, state);
 550			goto End;
 551		} else if (dev->class->resume) {
 552			pm_dev_dbg(dev, state, "legacy class ");
 553			error = legacy_resume(dev, dev->class->resume);
 554			goto End;
 555		}
 556	}
 557
 558	if (dev->bus) {
 559		if (dev->bus->pm) {
 560			pm_dev_dbg(dev, state, "");
 561			error = pm_op(dev, dev->bus->pm, state);
 562		} else if (dev->bus->resume) {
 563			pm_dev_dbg(dev, state, "legacy ");
 564			error = legacy_resume(dev, dev->bus->resume);
 565		}
 566	}
 567
 568 End:
 569	dev->power.is_suspended = false;
 570
 571 Unlock:
 572	device_unlock(dev);
 573	complete_all(&dev->power.completion);
 574
 575	TRACE_RESUME(error);
 576	return error;
 577}
 578
 579static void async_resume(void *data, async_cookie_t cookie)
 580{
 581	struct device *dev = (struct device *)data;
 582	int error;
 583
 584	error = device_resume(dev, pm_transition, true);
 585	if (error)
 586		pm_dev_err(dev, pm_transition, " async", error);
 587	put_device(dev);
 588}
 589
 590static bool is_async(struct device *dev)
 591{
 592	return dev->power.async_suspend && pm_async_enabled
 593		&& !pm_trace_is_enabled();
 594}
 595
 596/**
 597 *	dpm_drv_timeout - Driver suspend / resume watchdog handler
 598 *	@data: struct device which timed out
 599 *
 600 * 	Called when a driver has timed out suspending or resuming.
 601 * 	There's not much we can do here to recover so
 602 * 	BUG() out for a crash-dump
 603 *
 604 */
 605static void dpm_drv_timeout(unsigned long data)
 606{
 607	struct dpm_drv_wd_data *wd_data = (void *)data;
 608	struct device *dev = wd_data->dev;
 609	struct task_struct *tsk = wd_data->tsk;
 610
 611	printk(KERN_EMERG "**** DPM device timeout: %s (%s)\n", dev_name(dev),
 612	       (dev->driver ? dev->driver->name : "no driver"));
 613
 614#ifdef CONFIG_PLAT_RK
 615	resume_console();
 616#endif
 617	printk(KERN_EMERG "dpm suspend stack:\n");
 618	show_stack(tsk, NULL);
 619
 620	BUG();
 621}
 622
 623/**
 624 * dpm_resume - Execute "resume" callbacks for non-sysdev devices.
 625 * @state: PM transition of the system being carried out.
 626 *
 627 * Execute the appropriate "resume" callback for all devices whose status
 628 * indicates that they are suspended.
 629 */
 630void dpm_resume(pm_message_t state)
 631{
 632	struct device *dev;
 633	ktime_t starttime = ktime_get();
 634
 635	might_sleep();
 636
 637	mutex_lock(&dpm_list_mtx);
 638	pm_transition = state;
 639	async_error = 0;
 640
 641	list_for_each_entry(dev, &dpm_suspended_list, power.entry) {
 642		INIT_COMPLETION(dev->power.completion);
 643		if (is_async(dev)) {
 644			get_device(dev);
 645			async_schedule(async_resume, dev);
 646		}
 647	}
 648
 649	while (!list_empty(&dpm_suspended_list)) {
 650		dev = to_device(dpm_suspended_list.next);
 651		get_device(dev);
 652		if (!is_async(dev)) {
 653			int error;
 654
 655			mutex_unlock(&dpm_list_mtx);
 656
 657			error = device_resume(dev, state, false);
 658			if (error)
 659				pm_dev_err(dev, state, "", error);
 660
 661			mutex_lock(&dpm_list_mtx);
 662		}
 663		if (!list_empty(&dev->power.entry))
 664			list_move_tail(&dev->power.entry, &dpm_prepared_list);
 665		put_device(dev);
 666	}
 667	mutex_unlock(&dpm_list_mtx);
 668	async_synchronize_full();
 669	dpm_show_time(starttime, state, NULL);
 670}
 671
 672/**
 673 * device_complete - Complete a PM transition for given device.
 674 * @dev: Device to handle.
 675 * @state: PM transition of the system being carried out.
 676 */
 677static void device_complete(struct device *dev, pm_message_t state)
 678{
 679	device_lock(dev);
 680
 681	if (dev->pwr_domain) {
 682		pm_dev_dbg(dev, state, "completing power domain ");
 683		if (dev->pwr_domain->ops.complete)
 684			dev->pwr_domain->ops.complete(dev);
 685	} else if (dev->type && dev->type->pm) {
 686		pm_dev_dbg(dev, state, "completing type ");
 687		if (dev->type->pm->complete)
 688			dev->type->pm->complete(dev);
 689	} else if (dev->class && dev->class->pm) {
 690		pm_dev_dbg(dev, state, "completing class ");
 691		if (dev->class->pm->complete)
 692			dev->class->pm->complete(dev);
 693	} else if (dev->bus && dev->bus->pm) {
 694		pm_dev_dbg(dev, state, "completing ");
 695		if (dev->bus->pm->complete)
 696			dev->bus->pm->complete(dev);
 697	}
 698
 699	device_unlock(dev);
 700}
 701
 702/**
 703 * dpm_complete - Complete a PM transition for all non-sysdev devices.
 704 * @state: PM transition of the system being carried out.
 705 *
 706 * Execute the ->complete() callbacks for all devices whose PM status is not
 707 * DPM_ON (this allows new devices to be registered).
 708 */
 709void dpm_complete(pm_message_t state)
 710{
 711	struct list_head list;
 712
 713	might_sleep();
 714
 715	INIT_LIST_HEAD(&list);
 716	mutex_lock(&dpm_list_mtx);
 717	while (!list_empty(&dpm_prepared_list)) {
 718		struct device *dev = to_device(dpm_prepared_list.prev);
 719
 720		get_device(dev);
 721		dev->power.is_prepared = false;
 722		list_move(&dev->power.entry, &list);
 723		mutex_unlock(&dpm_list_mtx);
 724
 725		device_complete(dev, state);
 726
 727		mutex_lock(&dpm_list_mtx);
 728		put_device(dev);
 729	}
 730	list_splice(&list, &dpm_list);
 731	mutex_unlock(&dpm_list_mtx);
 732}
 733
 734/**
 735 * dpm_resume_end - Execute "resume" callbacks and complete system transition.
 736 * @state: PM transition of the system being carried out.
 737 *
 738 * Execute "resume" callbacks for all devices and complete the PM transition of
 739 * the system.
 740 */
 741void dpm_resume_end(pm_message_t state)
 742{
 743	dpm_resume(state);
 744	dpm_complete(state);
 745}
 746EXPORT_SYMBOL_GPL(dpm_resume_end);
 747
 748
 749/*------------------------- Suspend routines -------------------------*/
 750
 751/**
 752 * resume_event - Return a "resume" message for given "suspend" sleep state.
 753 * @sleep_state: PM message representing a sleep state.
 754 *
 755 * Return a PM message representing the resume event corresponding to given
 756 * sleep state.
 757 */
 758static pm_message_t resume_event(pm_message_t sleep_state)
 759{
 760	switch (sleep_state.event) {
 761	case PM_EVENT_SUSPEND:
 762		return PMSG_RESUME;
 763	case PM_EVENT_FREEZE:
 764	case PM_EVENT_QUIESCE:
 765		return PMSG_RECOVER;
 766	case PM_EVENT_HIBERNATE:
 767		return PMSG_RESTORE;
 768	}
 769	return PMSG_ON;
 770}
 771
 772/**
 773 * device_suspend_noirq - Execute a "late suspend" callback for given device.
 774 * @dev: Device to handle.
 775 * @state: PM transition of the system being carried out.
 776 *
 777 * The driver of @dev will not receive interrupts while this function is being
 778 * executed.
 779 */
 780static int device_suspend_noirq(struct device *dev, pm_message_t state)
 781{
 782	int error;
 783
 784	if (dev->pwr_domain) {
 785		pm_dev_dbg(dev, state, "LATE power domain ");
 786		error = pm_noirq_op(dev, &dev->pwr_domain->ops, state);
 787		if (error)
 788			return error;
 789	} else if (dev->type && dev->type->pm) {
 790		pm_dev_dbg(dev, state, "LATE type ");
 791		error = pm_noirq_op(dev, dev->type->pm, state);
 792		if (error)
 793			return error;
 794	} else if (dev->class && dev->class->pm) {
 795		pm_dev_dbg(dev, state, "LATE class ");
 796		error = pm_noirq_op(dev, dev->class->pm, state);
 797		if (error)
 798			return error;
 799	} else if (dev->bus && dev->bus->pm) {
 800		pm_dev_dbg(dev, state, "LATE ");
 801		error = pm_noirq_op(dev, dev->bus->pm, state);
 802		if (error)
 803			return error;
 804	}
 805
 806	return 0;
 807}
 808
 809/**
 810 * dpm_suspend_noirq - Execute "late suspend" callbacks for non-sysdev devices.
 811 * @state: PM transition of the system being carried out.
 812 *
 813 * Prevent device drivers from receiving interrupts and call the "noirq" suspend
 814 * handlers for all non-sysdev devices.
 815 */
 816int dpm_suspend_noirq(pm_message_t state)
 817{
 818	ktime_t starttime = ktime_get();
 819	int error = 0;
 820
 821	suspend_device_irqs();
 822	mutex_lock(&dpm_list_mtx);
 823	while (!list_empty(&dpm_suspended_list)) {
 824		struct device *dev = to_device(dpm_suspended_list.prev);
 825
 826		get_device(dev);
 827		mutex_unlock(&dpm_list_mtx);
 828
 829		error = device_suspend_noirq(dev, state);
 830
 831		mutex_lock(&dpm_list_mtx);
 832		if (error) {
 833			pm_dev_err(dev, state, " late", error);
 834			put_device(dev);
 835			break;
 836		}
 837		if (!list_empty(&dev->power.entry))
 838			list_move(&dev->power.entry, &dpm_noirq_list);
 839		put_device(dev);
 840	}
 841	mutex_unlock(&dpm_list_mtx);
 842	if (error)
 843		dpm_resume_noirq(resume_event(state));
 844	else
 845		dpm_show_time(starttime, state, "late");
 846	return error;
 847}
 848EXPORT_SYMBOL_GPL(dpm_suspend_noirq);
 849
 850/**
 851 * legacy_suspend - Execute a legacy (bus or class) suspend callback for device.
 852 * @dev: Device to suspend.
 853 * @state: PM transition of the system being carried out.
 854 * @cb: Suspend callback to execute.
 855 */
 856static int legacy_suspend(struct device *dev, pm_message_t state,
 857			  int (*cb)(struct device *dev, pm_message_t state))
 858{
 859	int error;
 860	ktime_t calltime;
 861
 862	calltime = initcall_debug_start(dev);
 863
 864	error = cb(dev, state);
 865	suspend_report_result(cb, error);
 866
 867	initcall_debug_report(dev, calltime, error);
 868
 869	return error;
 870}
 871
 872/**
 873 * device_suspend - Execute "suspend" callbacks for given device.
 874 * @dev: Device to handle.
 875 * @state: PM transition of the system being carried out.
 876 * @async: If true, the device is being suspended asynchronously.
 877 */
 878static int __device_suspend(struct device *dev, pm_message_t state, bool async)
 879{
 880	int error = 0;
 881	struct timer_list timer;
 882	struct dpm_drv_wd_data data;
 883
 884	dpm_wait_for_children(dev, async);
 885
 886	data.dev = dev;
 887	data.tsk = get_current();
 888	init_timer_on_stack(&timer);
 889	timer.expires = jiffies + HZ * 12;
 890	timer.function = dpm_drv_timeout;
 891	timer.data = (unsigned long)&data;
 892	add_timer(&timer);
 893
 894	device_lock(dev);
 895
 896	if (async_error)
 897		goto Unlock;
 898
 899	if (pm_wakeup_pending()) {
 900		async_error = -EBUSY;
 901		goto Unlock;
 902	}
 903
 904	if (dev->pwr_domain) {
 905		pm_dev_dbg(dev, state, "power domain ");
 906		error = pm_op(dev, &dev->pwr_domain->ops, state);
 907		goto End;
 908	}
 909
 910	if (dev->type && dev->type->pm) {
 911		pm_dev_dbg(dev, state, "type ");
 912		error = pm_op(dev, dev->type->pm, state);
 913		goto End;
 914	}
 915
 916	if (dev->class) {
 917		if (dev->class->pm) {
 918			pm_dev_dbg(dev, state, "class ");
 919			error = pm_op(dev, dev->class->pm, state);
 920			goto End;
 921		} else if (dev->class->suspend) {
 922			pm_dev_dbg(dev, state, "legacy class ");
 923			error = legacy_suspend(dev, state, dev->class->suspend);
 924			goto End;
 925		}
 926	}
 927
 928	if (dev->bus) {
 929		if (dev->bus->pm) {
 930			pm_dev_dbg(dev, state, "");
 931			error = pm_op(dev, dev->bus->pm, state);
 932		} else if (dev->bus->suspend) {
 933			pm_dev_dbg(dev, state, "legacy ");
 934			error = legacy_suspend(dev, state, dev->bus->suspend);
 935		}
 936	}
 937
 938 End:
 939	dev->power.is_suspended = !error;
 940
 941 Unlock:
 942	device_unlock(dev);
 943
 944	del_timer_sync(&timer);
 945	destroy_timer_on_stack(&timer);
 946
 947	complete_all(&dev->power.completion);
 948
 949	if (error)
 950		async_error = error;
 951
 952	return error;
 953}
 954
 955static void async_suspend(void *data, async_cookie_t cookie)
 956{
 957	struct device *dev = (struct device *)data;
 958	int error;
 959
 960	error = __device_suspend(dev, pm_transition, true);
 961	if (error)
 962		pm_dev_err(dev, pm_transition, " async", error);
 963
 964	put_device(dev);
 965}
 966
 967static int device_suspend(struct device *dev)
 968{
 969	INIT_COMPLETION(dev->power.completion);
 970
 971	if (pm_async_enabled && dev->power.async_suspend) {
 972		get_device(dev);
 973		async_schedule(async_suspend, dev);
 974		return 0;
 975	}
 976
 977	return __device_suspend(dev, pm_transition, false);
 978}
 979
 980/**
 981 * dpm_suspend - Execute "suspend" callbacks for all non-sysdev devices.
 982 * @state: PM transition of the system being carried out.
 983 */
 984int dpm_suspend(pm_message_t state)
 985{
 986	ktime_t starttime = ktime_get();
 987	int error = 0;
 988
 989	might_sleep();
 990
 991	mutex_lock(&dpm_list_mtx);
 992	pm_transition = state;
 993	async_error = 0;
 994	while (!list_empty(&dpm_prepared_list)) {
 995		struct device *dev = to_device(dpm_prepared_list.prev);
 996
 997		get_device(dev);
 998		mutex_unlock(&dpm_list_mtx);
 999
1000		error = device_suspend(dev);
1001
1002		mutex_lock(&dpm_list_mtx);
1003		if (error) {
1004			pm_dev_err(dev, state, "", error);
1005			put_device(dev);
1006			break;
1007		}
1008		if (!list_empty(&dev->power.entry))
1009			list_move(&dev->power.entry, &dpm_suspended_list);
1010		put_device(dev);
1011		if (async_error)
1012			break;
1013	}
1014	mutex_unlock(&dpm_list_mtx);
1015	async_synchronize_full();
1016	if (!error)
1017		error = async_error;
1018	if (!error)
1019		dpm_show_time(starttime, state, NULL);
1020	return error;
1021}
1022
1023/**
1024 * device_prepare - Prepare a device for system power transition.
1025 * @dev: Device to handle.
1026 * @state: PM transition of the system being carried out.
1027 *
1028 * Execute the ->prepare() callback(s) for given device.  No new children of the
1029 * device may be registered after this function has returned.
1030 */
1031static int device_prepare(struct device *dev, pm_message_t state)
1032{
1033	int error = 0;
1034
1035	device_lock(dev);
1036
1037	if (dev->pwr_domain) {
1038		pm_dev_dbg(dev, state, "preparing power domain ");
1039		if (dev->pwr_domain->ops.prepare)
1040			error = dev->pwr_domain->ops.prepare(dev);
1041		suspend_report_result(dev->pwr_domain->ops.prepare, error);
1042		if (error)
1043			goto End;
1044	} else if (dev->type && dev->type->pm) {
1045		pm_dev_dbg(dev, state, "preparing type ");
1046		if (dev->type->pm->prepare)
1047			error = dev->type->pm->prepare(dev);
1048		suspend_report_result(dev->type->pm->prepare, error);
1049		if (error)
1050			goto End;
1051	} else if (dev->class && dev->class->pm) {
1052		pm_dev_dbg(dev, state, "preparing class ");
1053		if (dev->class->pm->prepare)
1054			error = dev->class->pm->prepare(dev);
1055		suspend_report_result(dev->class->pm->prepare, error);
1056		if (error)
1057			goto End;
1058	} else if (dev->bus && dev->bus->pm) {
1059		pm_dev_dbg(dev, state, "preparing ");
1060		if (dev->bus->pm->prepare)
1061			error = dev->bus->pm->prepare(dev);
1062		suspend_report_result(dev->bus->pm->prepare, error);
1063	}
1064
1065 End:
1066	device_unlock(dev);
1067
1068	return error;
1069}
1070
1071/**
1072 * dpm_prepare - Prepare all non-sysdev devices for a system PM transition.
1073 * @state: PM transition of the system being carried out.
1074 *
1075 * Execute the ->prepare() callback(s) for all devices.
1076 */
1077int dpm_prepare(pm_message_t state)
1078{
1079	int error = 0;
1080
1081	might_sleep();
1082
1083	mutex_lock(&dpm_list_mtx);
1084	while (!list_empty(&dpm_list)) {
1085		struct device *dev = to_device(dpm_list.next);
1086
1087		get_device(dev);
1088		mutex_unlock(&dpm_list_mtx);
1089
1090		pm_runtime_get_noresume(dev);
1091		if (pm_runtime_barrier(dev) && device_may_wakeup(dev))
1092			pm_wakeup_event(dev, 0);
1093
1094		pm_runtime_put_sync(dev);
1095		error = pm_wakeup_pending() ?
1096				-EBUSY : device_prepare(dev, state);
1097
1098		mutex_lock(&dpm_list_mtx);
1099		if (error) {
1100			if (error == -EAGAIN) {
1101				put_device(dev);
1102				error = 0;
1103				continue;
1104			}
1105			printk(KERN_INFO "PM: Device %s not prepared "
1106				"for power transition: code %d\n",
1107				dev_name(dev), error);
1108			put_device(dev);
1109			break;
1110		}
1111		dev->power.is_prepared = true;
1112		if (!list_empty(&dev->power.entry))
1113			list_move_tail(&dev->power.entry, &dpm_prepared_list);
1114		put_device(dev);
1115	}
1116	mutex_unlock(&dpm_list_mtx);
1117	return error;
1118}
1119
1120/**
1121 * dpm_suspend_start - Prepare devices for PM transition and suspend them.
1122 * @state: PM transition of the system being carried out.
1123 *
1124 * Prepare all non-sysdev devices for system PM transition and execute "suspend"
1125 * callbacks for them.
1126 */
1127int dpm_suspend_start(pm_message_t state)
1128{
1129	int error;
1130
1131	error = dpm_prepare(state);
1132	if (!error)
1133		error = dpm_suspend(state);
1134	return error;
1135}
1136EXPORT_SYMBOL_GPL(dpm_suspend_start);
1137
1138void __suspend_report_result(const char *function, void *fn, int ret)
1139{
1140	if (ret)
1141		printk(KERN_ERR "%s(): %pF returns %d\n", function, fn, ret);
1142}
1143EXPORT_SYMBOL_GPL(__suspend_report_result);
1144
1145/**
1146 * device_pm_wait_for_dev - Wait for suspend/resume of a device to complete.
1147 * @dev: Device to wait for.
1148 * @subordinate: Device that needs to wait for @dev.
1149 */
1150int device_pm_wait_for_dev(struct device *subordinate, struct device *dev)
1151{
1152	dpm_wait(dev, subordinate->power.async_suspend);
1153	return async_error;
1154}
1155EXPORT_SYMBOL_GPL(device_pm_wait_for_dev);