linux/include/linux/pm.h
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   1/* SPDX-License-Identifier: GPL-2.0-or-later */
   2/*
   3 *  pm.h - Power management interface
   4 *
   5 *  Copyright (C) 2000 Andrew Henroid
   6 */
   7
   8#ifndef _LINUX_PM_H
   9#define _LINUX_PM_H
  10
  11#include <linux/export.h>
  12#include <linux/list.h>
  13#include <linux/workqueue.h>
  14#include <linux/spinlock.h>
  15#include <linux/wait.h>
  16#include <linux/timer.h>
  17#include <linux/hrtimer.h>
  18#include <linux/completion.h>
  19
  20/*
  21 * Callbacks for platform drivers to implement.
  22 */
  23extern void (*pm_power_off)(void);
  24
  25struct device; /* we have a circular dep with device.h */
  26#ifdef CONFIG_VT_CONSOLE_SLEEP
  27extern void pm_vt_switch_required(struct device *dev, bool required);
  28extern void pm_vt_switch_unregister(struct device *dev);
  29#else
  30static inline void pm_vt_switch_required(struct device *dev, bool required)
  31{
  32}
  33static inline void pm_vt_switch_unregister(struct device *dev)
  34{
  35}
  36#endif /* CONFIG_VT_CONSOLE_SLEEP */
  37
  38#ifdef CONFIG_CXL_SUSPEND
  39bool cxl_mem_active(void);
  40#else
  41static inline bool cxl_mem_active(void)
  42{
  43        return false;
  44}
  45#endif
  46
  47/*
  48 * Device power management
  49 */
  50
  51
  52#ifdef CONFIG_PM
  53extern const char power_group_name[];           /* = "power" */
  54#else
  55#define power_group_name        NULL
  56#endif
  57
  58typedef struct pm_message {
  59        int event;
  60} pm_message_t;
  61
  62/**
  63 * struct dev_pm_ops - device PM callbacks.
  64 *
  65 * @prepare: The principal role of this callback is to prevent new children of
  66 *      the device from being registered after it has returned (the driver's
  67 *      subsystem and generally the rest of the kernel is supposed to prevent
  68 *      new calls to the probe method from being made too once @prepare() has
  69 *      succeeded).  If @prepare() detects a situation it cannot handle (e.g.
  70 *      registration of a child already in progress), it may return -EAGAIN, so
  71 *      that the PM core can execute it once again (e.g. after a new child has
  72 *      been registered) to recover from the race condition.
  73 *      This method is executed for all kinds of suspend transitions and is
  74 *      followed by one of the suspend callbacks: @suspend(), @freeze(), or
  75 *      @poweroff().  If the transition is a suspend to memory or standby (that
  76 *      is, not related to hibernation), the return value of @prepare() may be
  77 *      used to indicate to the PM core to leave the device in runtime suspend
  78 *      if applicable.  Namely, if @prepare() returns a positive number, the PM
  79 *      core will understand that as a declaration that the device appears to be
  80 *      runtime-suspended and it may be left in that state during the entire
  81 *      transition and during the subsequent resume if all of its descendants
  82 *      are left in runtime suspend too.  If that happens, @complete() will be
  83 *      executed directly after @prepare() and it must ensure the proper
  84 *      functioning of the device after the system resume.
  85 *      The PM core executes subsystem-level @prepare() for all devices before
  86 *      starting to invoke suspend callbacks for any of them, so generally
  87 *      devices may be assumed to be functional or to respond to runtime resume
  88 *      requests while @prepare() is being executed.  However, device drivers
  89 *      may NOT assume anything about the availability of user space at that
  90 *      time and it is NOT valid to request firmware from within @prepare()
  91 *      (it's too late to do that).  It also is NOT valid to allocate
  92 *      substantial amounts of memory from @prepare() in the GFP_KERNEL mode.
  93 *      [To work around these limitations, drivers may register suspend and
  94 *      hibernation notifiers to be executed before the freezing of tasks.]
  95 *
  96 * @complete: Undo the changes made by @prepare().  This method is executed for
  97 *      all kinds of resume transitions, following one of the resume callbacks:
  98 *      @resume(), @thaw(), @restore().  Also called if the state transition
  99 *      fails before the driver's suspend callback: @suspend(), @freeze() or
 100 *      @poweroff(), can be executed (e.g. if the suspend callback fails for one
 101 *      of the other devices that the PM core has unsuccessfully attempted to
 102 *      suspend earlier).
 103 *      The PM core executes subsystem-level @complete() after it has executed
 104 *      the appropriate resume callbacks for all devices.  If the corresponding
 105 *      @prepare() at the beginning of the suspend transition returned a
 106 *      positive number and the device was left in runtime suspend (without
 107 *      executing any suspend and resume callbacks for it), @complete() will be
 108 *      the only callback executed for the device during resume.  In that case,
 109 *      @complete() must be prepared to do whatever is necessary to ensure the
 110 *      proper functioning of the device after the system resume.  To this end,
 111 *      @complete() can check the power.direct_complete flag of the device to
 112 *      learn whether (unset) or not (set) the previous suspend and resume
 113 *      callbacks have been executed for it.
 114 *
 115 * @suspend: Executed before putting the system into a sleep state in which the
 116 *      contents of main memory are preserved.  The exact action to perform
 117 *      depends on the device's subsystem (PM domain, device type, class or bus
 118 *      type), but generally the device must be quiescent after subsystem-level
 119 *      @suspend() has returned, so that it doesn't do any I/O or DMA.
 120 *      Subsystem-level @suspend() is executed for all devices after invoking
 121 *      subsystem-level @prepare() for all of them.
 122 *
 123 * @suspend_late: Continue operations started by @suspend().  For a number of
 124 *      devices @suspend_late() may point to the same callback routine as the
 125 *      runtime suspend callback.
 126 *
 127 * @resume: Executed after waking the system up from a sleep state in which the
 128 *      contents of main memory were preserved.  The exact action to perform
 129 *      depends on the device's subsystem, but generally the driver is expected
 130 *      to start working again, responding to hardware events and software
 131 *      requests (the device itself may be left in a low-power state, waiting
 132 *      for a runtime resume to occur).  The state of the device at the time its
 133 *      driver's @resume() callback is run depends on the platform and subsystem
 134 *      the device belongs to.  On most platforms, there are no restrictions on
 135 *      availability of resources like clocks during @resume().
 136 *      Subsystem-level @resume() is executed for all devices after invoking
 137 *      subsystem-level @resume_noirq() for all of them.
 138 *
 139 * @resume_early: Prepare to execute @resume().  For a number of devices
 140 *      @resume_early() may point to the same callback routine as the runtime
 141 *      resume callback.
 142 *
 143 * @freeze: Hibernation-specific, executed before creating a hibernation image.
 144 *      Analogous to @suspend(), but it should not enable the device to signal
 145 *      wakeup events or change its power state.  The majority of subsystems
 146 *      (with the notable exception of the PCI bus type) expect the driver-level
 147 *      @freeze() to save the device settings in memory to be used by @restore()
 148 *      during the subsequent resume from hibernation.
 149 *      Subsystem-level @freeze() is executed for all devices after invoking
 150 *      subsystem-level @prepare() for all of them.
 151 *
 152 * @freeze_late: Continue operations started by @freeze().  Analogous to
 153 *      @suspend_late(), but it should not enable the device to signal wakeup
 154 *      events or change its power state.
 155 *
 156 * @thaw: Hibernation-specific, executed after creating a hibernation image OR
 157 *      if the creation of an image has failed.  Also executed after a failing
 158 *      attempt to restore the contents of main memory from such an image.
 159 *      Undo the changes made by the preceding @freeze(), so the device can be
 160 *      operated in the same way as immediately before the call to @freeze().
 161 *      Subsystem-level @thaw() is executed for all devices after invoking
 162 *      subsystem-level @thaw_noirq() for all of them.  It also may be executed
 163 *      directly after @freeze() in case of a transition error.
 164 *
 165 * @thaw_early: Prepare to execute @thaw().  Undo the changes made by the
 166 *      preceding @freeze_late().
 167 *
 168 * @poweroff: Hibernation-specific, executed after saving a hibernation image.
 169 *      Analogous to @suspend(), but it need not save the device's settings in
 170 *      memory.
 171 *      Subsystem-level @poweroff() is executed for all devices after invoking
 172 *      subsystem-level @prepare() for all of them.
 173 *
 174 * @poweroff_late: Continue operations started by @poweroff().  Analogous to
 175 *      @suspend_late(), but it need not save the device's settings in memory.
 176 *
 177 * @restore: Hibernation-specific, executed after restoring the contents of main
 178 *      memory from a hibernation image, analogous to @resume().
 179 *
 180 * @restore_early: Prepare to execute @restore(), analogous to @resume_early().
 181 *
 182 * @suspend_noirq: Complete the actions started by @suspend().  Carry out any
 183 *      additional operations required for suspending the device that might be
 184 *      racing with its driver's interrupt handler, which is guaranteed not to
 185 *      run while @suspend_noirq() is being executed.
 186 *      It generally is expected that the device will be in a low-power state
 187 *      (appropriate for the target system sleep state) after subsystem-level
 188 *      @suspend_noirq() has returned successfully.  If the device can generate
 189 *      system wakeup signals and is enabled to wake up the system, it should be
 190 *      configured to do so at that time.  However, depending on the platform
 191 *      and device's subsystem, @suspend() or @suspend_late() may be allowed to
 192 *      put the device into the low-power state and configure it to generate
 193 *      wakeup signals, in which case it generally is not necessary to define
 194 *      @suspend_noirq().
 195 *
 196 * @resume_noirq: Prepare for the execution of @resume() by carrying out any
 197 *      operations required for resuming the device that might be racing with
 198 *      its driver's interrupt handler, which is guaranteed not to run while
 199 *      @resume_noirq() is being executed.
 200 *
 201 * @freeze_noirq: Complete the actions started by @freeze().  Carry out any
 202 *      additional operations required for freezing the device that might be
 203 *      racing with its driver's interrupt handler, which is guaranteed not to
 204 *      run while @freeze_noirq() is being executed.
 205 *      The power state of the device should not be changed by either @freeze(),
 206 *      or @freeze_late(), or @freeze_noirq() and it should not be configured to
 207 *      signal system wakeup by any of these callbacks.
 208 *
 209 * @thaw_noirq: Prepare for the execution of @thaw() by carrying out any
 210 *      operations required for thawing the device that might be racing with its
 211 *      driver's interrupt handler, which is guaranteed not to run while
 212 *      @thaw_noirq() is being executed.
 213 *
 214 * @poweroff_noirq: Complete the actions started by @poweroff().  Analogous to
 215 *      @suspend_noirq(), but it need not save the device's settings in memory.
 216 *
 217 * @restore_noirq: Prepare for the execution of @restore() by carrying out any
 218 *      operations required for thawing the device that might be racing with its
 219 *      driver's interrupt handler, which is guaranteed not to run while
 220 *      @restore_noirq() is being executed.  Analogous to @resume_noirq().
 221 *
 222 * @runtime_suspend: Prepare the device for a condition in which it won't be
 223 *      able to communicate with the CPU(s) and RAM due to power management.
 224 *      This need not mean that the device should be put into a low-power state.
 225 *      For example, if the device is behind a link which is about to be turned
 226 *      off, the device may remain at full power.  If the device does go to low
 227 *      power and is capable of generating runtime wakeup events, remote wakeup
 228 *      (i.e., a hardware mechanism allowing the device to request a change of
 229 *      its power state via an interrupt) should be enabled for it.
 230 *
 231 * @runtime_resume: Put the device into the fully active state in response to a
 232 *      wakeup event generated by hardware or at the request of software.  If
 233 *      necessary, put the device into the full-power state and restore its
 234 *      registers, so that it is fully operational.
 235 *
 236 * @runtime_idle: Device appears to be inactive and it might be put into a
 237 *      low-power state if all of the necessary conditions are satisfied.
 238 *      Check these conditions, and return 0 if it's appropriate to let the PM
 239 *      core queue a suspend request for the device.
 240 *
 241 * Several device power state transitions are externally visible, affecting
 242 * the state of pending I/O queues and (for drivers that touch hardware)
 243 * interrupts, wakeups, DMA, and other hardware state.  There may also be
 244 * internal transitions to various low-power modes which are transparent
 245 * to the rest of the driver stack (such as a driver that's ON gating off
 246 * clocks which are not in active use).
 247 *
 248 * The externally visible transitions are handled with the help of callbacks
 249 * included in this structure in such a way that, typically, two levels of
 250 * callbacks are involved.  First, the PM core executes callbacks provided by PM
 251 * domains, device types, classes and bus types.  They are the subsystem-level
 252 * callbacks expected to execute callbacks provided by device drivers, although
 253 * they may choose not to do that.  If the driver callbacks are executed, they
 254 * have to collaborate with the subsystem-level callbacks to achieve the goals
 255 * appropriate for the given system transition, given transition phase and the
 256 * subsystem the device belongs to.
 257 *
 258 * All of the above callbacks, except for @complete(), return error codes.
 259 * However, the error codes returned by @resume(), @thaw(), @restore(),
 260 * @resume_noirq(), @thaw_noirq(), and @restore_noirq(), do not cause the PM
 261 * core to abort the resume transition during which they are returned.  The
 262 * error codes returned in those cases are only printed to the system logs for
 263 * debugging purposes.  Still, it is recommended that drivers only return error
 264 * codes from their resume methods in case of an unrecoverable failure (i.e.
 265 * when the device being handled refuses to resume and becomes unusable) to
 266 * allow the PM core to be modified in the future, so that it can avoid
 267 * attempting to handle devices that failed to resume and their children.
 268 *
 269 * It is allowed to unregister devices while the above callbacks are being
 270 * executed.  However, a callback routine MUST NOT try to unregister the device
 271 * it was called for, although it may unregister children of that device (for
 272 * example, if it detects that a child was unplugged while the system was
 273 * asleep).
 274 *
 275 * There also are callbacks related to runtime power management of devices.
 276 * Again, as a rule these callbacks are executed by the PM core for subsystems
 277 * (PM domains, device types, classes and bus types) and the subsystem-level
 278 * callbacks are expected to invoke the driver callbacks.  Moreover, the exact
 279 * actions to be performed by a device driver's callbacks generally depend on
 280 * the platform and subsystem the device belongs to.
 281 *
 282 * Refer to Documentation/power/runtime_pm.rst for more information about the
 283 * role of the @runtime_suspend(), @runtime_resume() and @runtime_idle()
 284 * callbacks in device runtime power management.
 285 */
 286struct dev_pm_ops {
 287        int (*prepare)(struct device *dev);
 288        void (*complete)(struct device *dev);
 289        int (*suspend)(struct device *dev);
 290        int (*resume)(struct device *dev);
 291        int (*freeze)(struct device *dev);
 292        int (*thaw)(struct device *dev);
 293        int (*poweroff)(struct device *dev);
 294        int (*restore)(struct device *dev);
 295        int (*suspend_late)(struct device *dev);
 296        int (*resume_early)(struct device *dev);
 297        int (*freeze_late)(struct device *dev);
 298        int (*thaw_early)(struct device *dev);
 299        int (*poweroff_late)(struct device *dev);
 300        int (*restore_early)(struct device *dev);
 301        int (*suspend_noirq)(struct device *dev);
 302        int (*resume_noirq)(struct device *dev);
 303        int (*freeze_noirq)(struct device *dev);
 304        int (*thaw_noirq)(struct device *dev);
 305        int (*poweroff_noirq)(struct device *dev);
 306        int (*restore_noirq)(struct device *dev);
 307        int (*runtime_suspend)(struct device *dev);
 308        int (*runtime_resume)(struct device *dev);
 309        int (*runtime_idle)(struct device *dev);
 310};
 311
 312#define SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
 313        .suspend = pm_sleep_ptr(suspend_fn), \
 314        .resume = pm_sleep_ptr(resume_fn), \
 315        .freeze = pm_sleep_ptr(suspend_fn), \
 316        .thaw = pm_sleep_ptr(resume_fn), \
 317        .poweroff = pm_sleep_ptr(suspend_fn), \
 318        .restore = pm_sleep_ptr(resume_fn),
 319
 320#define LATE_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
 321        .suspend_late = pm_sleep_ptr(suspend_fn), \
 322        .resume_early = pm_sleep_ptr(resume_fn), \
 323        .freeze_late = pm_sleep_ptr(suspend_fn), \
 324        .thaw_early = pm_sleep_ptr(resume_fn), \
 325        .poweroff_late = pm_sleep_ptr(suspend_fn), \
 326        .restore_early = pm_sleep_ptr(resume_fn),
 327
 328#define NOIRQ_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
 329        .suspend_noirq = pm_sleep_ptr(suspend_fn), \
 330        .resume_noirq = pm_sleep_ptr(resume_fn), \
 331        .freeze_noirq = pm_sleep_ptr(suspend_fn), \
 332        .thaw_noirq = pm_sleep_ptr(resume_fn), \
 333        .poweroff_noirq = pm_sleep_ptr(suspend_fn), \
 334        .restore_noirq = pm_sleep_ptr(resume_fn),
 335
 336#define RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn) \
 337        .runtime_suspend = suspend_fn, \
 338        .runtime_resume = resume_fn, \
 339        .runtime_idle = idle_fn,
 340
 341#ifdef CONFIG_PM_SLEEP
 342#define SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
 343        SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn)
 344#else
 345#define SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn)
 346#endif
 347
 348#ifdef CONFIG_PM_SLEEP
 349#define SET_LATE_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
 350        LATE_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn)
 351#else
 352#define SET_LATE_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn)
 353#endif
 354
 355#ifdef CONFIG_PM_SLEEP
 356#define SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
 357        NOIRQ_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn)
 358#else
 359#define SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn)
 360#endif
 361
 362#ifdef CONFIG_PM
 363#define SET_RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn) \
 364        RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn)
 365#else
 366#define SET_RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn)
 367#endif
 368
 369#define _DEFINE_DEV_PM_OPS(name, \
 370                           suspend_fn, resume_fn, \
 371                           runtime_suspend_fn, runtime_resume_fn, idle_fn) \
 372const struct dev_pm_ops name = { \
 373        SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
 374        RUNTIME_PM_OPS(runtime_suspend_fn, runtime_resume_fn, idle_fn) \
 375}
 376
 377#ifdef CONFIG_PM
 378#define _EXPORT_DEV_PM_OPS(name, suspend_fn, resume_fn, runtime_suspend_fn, \
 379                           runtime_resume_fn, idle_fn, sec, ns)         \
 380        _DEFINE_DEV_PM_OPS(name, suspend_fn, resume_fn, runtime_suspend_fn, \
 381                           runtime_resume_fn, idle_fn); \
 382        __EXPORT_SYMBOL(name, sec, ns)
 383#else
 384#define _EXPORT_DEV_PM_OPS(name, suspend_fn, resume_fn, runtime_suspend_fn, \
 385                           runtime_resume_fn, idle_fn, sec, ns) \
 386static __maybe_unused _DEFINE_DEV_PM_OPS(__static_##name, suspend_fn, \
 387                                         resume_fn, runtime_suspend_fn, \
 388                                         runtime_resume_fn, idle_fn)
 389#endif
 390
 391/*
 392 * Use this if you want to use the same suspend and resume callbacks for suspend
 393 * to RAM and hibernation.
 394 *
 395 * If the underlying dev_pm_ops struct symbol has to be exported, use
 396 * EXPORT_SIMPLE_DEV_PM_OPS() or EXPORT_GPL_SIMPLE_DEV_PM_OPS() instead.
 397 */
 398#define DEFINE_SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn) \
 399        _DEFINE_DEV_PM_OPS(name, suspend_fn, resume_fn, NULL, NULL, NULL)
 400
 401#define EXPORT_SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn) \
 402        _EXPORT_DEV_PM_OPS(name, suspend_fn, resume_fn, NULL, NULL, NULL, "", "")
 403#define EXPORT_GPL_SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn) \
 404        _EXPORT_DEV_PM_OPS(name, suspend_fn, resume_fn, NULL, NULL, NULL, "_gpl", "")
 405#define EXPORT_NS_SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn, ns)    \
 406        _EXPORT_DEV_PM_OPS(name, suspend_fn, resume_fn, NULL, NULL, NULL, "", #ns)
 407#define EXPORT_NS_GPL_SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn, ns)        \
 408        _EXPORT_DEV_PM_OPS(name, suspend_fn, resume_fn, NULL, NULL, NULL, "_gpl", #ns)
 409
 410/* Deprecated. Use DEFINE_SIMPLE_DEV_PM_OPS() instead. */
 411#define SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn) \
 412const struct dev_pm_ops __maybe_unused name = { \
 413        SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
 414}
 415
 416/*
 417 * Use this for defining a set of PM operations to be used in all situations
 418 * (system suspend, hibernation or runtime PM).
 419 * NOTE: In general, system suspend callbacks, .suspend() and .resume(), should
 420 * be different from the corresponding runtime PM callbacks, .runtime_suspend(),
 421 * and .runtime_resume(), because .runtime_suspend() always works on an already
 422 * quiescent device, while .suspend() should assume that the device may be doing
 423 * something when it is called (it should ensure that the device will be
 424 * quiescent after it has returned).  Therefore it's better to point the "late"
 425 * suspend and "early" resume callback pointers, .suspend_late() and
 426 * .resume_early(), to the same routines as .runtime_suspend() and
 427 * .runtime_resume(), respectively (and analogously for hibernation).
 428 *
 429 * Deprecated. You most likely don't want this macro. Use
 430 * DEFINE_RUNTIME_DEV_PM_OPS() instead.
 431 */
 432#define UNIVERSAL_DEV_PM_OPS(name, suspend_fn, resume_fn, idle_fn) \
 433const struct dev_pm_ops __maybe_unused name = { \
 434        SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
 435        SET_RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn) \
 436}
 437
 438#define pm_ptr(_ptr) PTR_IF(IS_ENABLED(CONFIG_PM), (_ptr))
 439#define pm_sleep_ptr(_ptr) PTR_IF(IS_ENABLED(CONFIG_PM_SLEEP), (_ptr))
 440
 441/*
 442 * PM_EVENT_ messages
 443 *
 444 * The following PM_EVENT_ messages are defined for the internal use of the PM
 445 * core, in order to provide a mechanism allowing the high level suspend and
 446 * hibernation code to convey the necessary information to the device PM core
 447 * code:
 448 *
 449 * ON           No transition.
 450 *
 451 * FREEZE       System is going to hibernate, call ->prepare() and ->freeze()
 452 *              for all devices.
 453 *
 454 * SUSPEND      System is going to suspend, call ->prepare() and ->suspend()
 455 *              for all devices.
 456 *
 457 * HIBERNATE    Hibernation image has been saved, call ->prepare() and
 458 *              ->poweroff() for all devices.
 459 *
 460 * QUIESCE      Contents of main memory are going to be restored from a (loaded)
 461 *              hibernation image, call ->prepare() and ->freeze() for all
 462 *              devices.
 463 *
 464 * RESUME       System is resuming, call ->resume() and ->complete() for all
 465 *              devices.
 466 *
 467 * THAW         Hibernation image has been created, call ->thaw() and
 468 *              ->complete() for all devices.
 469 *
 470 * RESTORE      Contents of main memory have been restored from a hibernation
 471 *              image, call ->restore() and ->complete() for all devices.
 472 *
 473 * RECOVER      Creation of a hibernation image or restoration of the main
 474 *              memory contents from a hibernation image has failed, call
 475 *              ->thaw() and ->complete() for all devices.
 476 *
 477 * The following PM_EVENT_ messages are defined for internal use by
 478 * kernel subsystems.  They are never issued by the PM core.
 479 *
 480 * USER_SUSPEND         Manual selective suspend was issued by userspace.
 481 *
 482 * USER_RESUME          Manual selective resume was issued by userspace.
 483 *
 484 * REMOTE_WAKEUP        Remote-wakeup request was received from the device.
 485 *
 486 * AUTO_SUSPEND         Automatic (device idle) runtime suspend was
 487 *                      initiated by the subsystem.
 488 *
 489 * AUTO_RESUME          Automatic (device needed) runtime resume was
 490 *                      requested by a driver.
 491 */
 492
 493#define PM_EVENT_INVALID        (-1)
 494#define PM_EVENT_ON             0x0000
 495#define PM_EVENT_FREEZE         0x0001
 496#define PM_EVENT_SUSPEND        0x0002
 497#define PM_EVENT_HIBERNATE      0x0004
 498#define PM_EVENT_QUIESCE        0x0008
 499#define PM_EVENT_RESUME         0x0010
 500#define PM_EVENT_THAW           0x0020
 501#define PM_EVENT_RESTORE        0x0040
 502#define PM_EVENT_RECOVER        0x0080
 503#define PM_EVENT_USER           0x0100
 504#define PM_EVENT_REMOTE         0x0200
 505#define PM_EVENT_AUTO           0x0400
 506
 507#define PM_EVENT_SLEEP          (PM_EVENT_SUSPEND | PM_EVENT_HIBERNATE)
 508#define PM_EVENT_USER_SUSPEND   (PM_EVENT_USER | PM_EVENT_SUSPEND)
 509#define PM_EVENT_USER_RESUME    (PM_EVENT_USER | PM_EVENT_RESUME)
 510#define PM_EVENT_REMOTE_RESUME  (PM_EVENT_REMOTE | PM_EVENT_RESUME)
 511#define PM_EVENT_AUTO_SUSPEND   (PM_EVENT_AUTO | PM_EVENT_SUSPEND)
 512#define PM_EVENT_AUTO_RESUME    (PM_EVENT_AUTO | PM_EVENT_RESUME)
 513
 514#define PMSG_INVALID    ((struct pm_message){ .event = PM_EVENT_INVALID, })
 515#define PMSG_ON         ((struct pm_message){ .event = PM_EVENT_ON, })
 516#define PMSG_FREEZE     ((struct pm_message){ .event = PM_EVENT_FREEZE, })
 517#define PMSG_QUIESCE    ((struct pm_message){ .event = PM_EVENT_QUIESCE, })
 518#define PMSG_SUSPEND    ((struct pm_message){ .event = PM_EVENT_SUSPEND, })
 519#define PMSG_HIBERNATE  ((struct pm_message){ .event = PM_EVENT_HIBERNATE, })
 520#define PMSG_RESUME     ((struct pm_message){ .event = PM_EVENT_RESUME, })
 521#define PMSG_THAW       ((struct pm_message){ .event = PM_EVENT_THAW, })
 522#define PMSG_RESTORE    ((struct pm_message){ .event = PM_EVENT_RESTORE, })
 523#define PMSG_RECOVER    ((struct pm_message){ .event = PM_EVENT_RECOVER, })
 524#define PMSG_USER_SUSPEND       ((struct pm_message) \
 525                                        { .event = PM_EVENT_USER_SUSPEND, })
 526#define PMSG_USER_RESUME        ((struct pm_message) \
 527                                        { .event = PM_EVENT_USER_RESUME, })
 528#define PMSG_REMOTE_RESUME      ((struct pm_message) \
 529                                        { .event = PM_EVENT_REMOTE_RESUME, })
 530#define PMSG_AUTO_SUSPEND       ((struct pm_message) \
 531                                        { .event = PM_EVENT_AUTO_SUSPEND, })
 532#define PMSG_AUTO_RESUME        ((struct pm_message) \
 533                                        { .event = PM_EVENT_AUTO_RESUME, })
 534
 535#define PMSG_IS_AUTO(msg)       (((msg).event & PM_EVENT_AUTO) != 0)
 536
 537/*
 538 * Device run-time power management status.
 539 *
 540 * These status labels are used internally by the PM core to indicate the
 541 * current status of a device with respect to the PM core operations.  They do
 542 * not reflect the actual power state of the device or its status as seen by the
 543 * driver.
 544 *
 545 * RPM_ACTIVE           Device is fully operational.  Indicates that the device
 546 *                      bus type's ->runtime_resume() callback has completed
 547 *                      successfully.
 548 *
 549 * RPM_SUSPENDED        Device bus type's ->runtime_suspend() callback has
 550 *                      completed successfully.  The device is regarded as
 551 *                      suspended.
 552 *
 553 * RPM_RESUMING         Device bus type's ->runtime_resume() callback is being
 554 *                      executed.
 555 *
 556 * RPM_SUSPENDING       Device bus type's ->runtime_suspend() callback is being
 557 *                      executed.
 558 */
 559
 560enum rpm_status {
 561        RPM_INVALID = -1,
 562        RPM_ACTIVE = 0,
 563        RPM_RESUMING,
 564        RPM_SUSPENDED,
 565        RPM_SUSPENDING,
 566};
 567
 568/*
 569 * Device run-time power management request types.
 570 *
 571 * RPM_REQ_NONE         Do nothing.
 572 *
 573 * RPM_REQ_IDLE         Run the device bus type's ->runtime_idle() callback
 574 *
 575 * RPM_REQ_SUSPEND      Run the device bus type's ->runtime_suspend() callback
 576 *
 577 * RPM_REQ_AUTOSUSPEND  Same as RPM_REQ_SUSPEND, but not until the device has
 578 *                      been inactive for as long as power.autosuspend_delay
 579 *
 580 * RPM_REQ_RESUME       Run the device bus type's ->runtime_resume() callback
 581 */
 582
 583enum rpm_request {
 584        RPM_REQ_NONE = 0,
 585        RPM_REQ_IDLE,
 586        RPM_REQ_SUSPEND,
 587        RPM_REQ_AUTOSUSPEND,
 588        RPM_REQ_RESUME,
 589};
 590
 591struct wakeup_source;
 592struct wake_irq;
 593struct pm_domain_data;
 594
 595struct pm_subsys_data {
 596        spinlock_t lock;
 597        unsigned int refcount;
 598#ifdef CONFIG_PM_CLK
 599        unsigned int clock_op_might_sleep;
 600        struct mutex clock_mutex;
 601        struct list_head clock_list;
 602#endif
 603#ifdef CONFIG_PM_GENERIC_DOMAINS
 604        struct pm_domain_data *domain_data;
 605#endif
 606};
 607
 608/*
 609 * Driver flags to control system suspend/resume behavior.
 610 *
 611 * These flags can be set by device drivers at the probe time.  They need not be
 612 * cleared by the drivers as the driver core will take care of that.
 613 *
 614 * NO_DIRECT_COMPLETE: Do not apply direct-complete optimization to the device.
 615 * SMART_PREPARE: Take the driver ->prepare callback return value into account.
 616 * SMART_SUSPEND: Avoid resuming the device from runtime suspend.
 617 * MAY_SKIP_RESUME: Allow driver "noirq" and "early" callbacks to be skipped.
 618 *
 619 * See Documentation/driver-api/pm/devices.rst for details.
 620 */
 621#define DPM_FLAG_NO_DIRECT_COMPLETE     BIT(0)
 622#define DPM_FLAG_SMART_PREPARE          BIT(1)
 623#define DPM_FLAG_SMART_SUSPEND          BIT(2)
 624#define DPM_FLAG_MAY_SKIP_RESUME        BIT(3)
 625
 626struct dev_pm_info {
 627        pm_message_t            power_state;
 628        unsigned int            can_wakeup:1;
 629        unsigned int            async_suspend:1;
 630        bool                    in_dpm_list:1;  /* Owned by the PM core */
 631        bool                    is_prepared:1;  /* Owned by the PM core */
 632        bool                    is_suspended:1; /* Ditto */
 633        bool                    is_noirq_suspended:1;
 634        bool                    is_late_suspended:1;
 635        bool                    no_pm:1;
 636        bool                    early_init:1;   /* Owned by the PM core */
 637        bool                    direct_complete:1;      /* Owned by the PM core */
 638        u32                     driver_flags;
 639        spinlock_t              lock;
 640#ifdef CONFIG_PM_SLEEP
 641        struct list_head        entry;
 642        struct completion       completion;
 643        struct wakeup_source    *wakeup;
 644        bool                    wakeup_path:1;
 645        bool                    syscore:1;
 646        bool                    no_pm_callbacks:1;      /* Owned by the PM core */
 647        unsigned int            must_resume:1;  /* Owned by the PM core */
 648        unsigned int            may_skip_resume:1;      /* Set by subsystems */
 649#else
 650        unsigned int            should_wakeup:1;
 651#endif
 652#ifdef CONFIG_PM
 653        struct hrtimer          suspend_timer;
 654        u64                     timer_expires;
 655        struct work_struct      work;
 656        wait_queue_head_t       wait_queue;
 657        struct wake_irq         *wakeirq;
 658        atomic_t                usage_count;
 659        atomic_t                child_count;
 660        unsigned int            disable_depth:3;
 661        unsigned int            idle_notification:1;
 662        unsigned int            request_pending:1;
 663        unsigned int            deferred_resume:1;
 664        unsigned int            needs_force_resume:1;
 665        unsigned int            runtime_auto:1;
 666        bool                    ignore_children:1;
 667        unsigned int            no_callbacks:1;
 668        unsigned int            irq_safe:1;
 669        unsigned int            use_autosuspend:1;
 670        unsigned int            timer_autosuspends:1;
 671        unsigned int            memalloc_noio:1;
 672        unsigned int            links_count;
 673        enum rpm_request        request;
 674        enum rpm_status         runtime_status;
 675        enum rpm_status         last_status;
 676        int                     runtime_error;
 677        int                     autosuspend_delay;
 678        u64                     last_busy;
 679        u64                     active_time;
 680        u64                     suspended_time;
 681        u64                     accounting_timestamp;
 682#endif
 683        struct pm_subsys_data   *subsys_data;  /* Owned by the subsystem. */
 684        void (*set_latency_tolerance)(struct device *, s32);
 685        struct dev_pm_qos       *qos;
 686};
 687
 688extern int dev_pm_get_subsys_data(struct device *dev);
 689extern void dev_pm_put_subsys_data(struct device *dev);
 690
 691/**
 692 * struct dev_pm_domain - power management domain representation.
 693 *
 694 * @ops: Power management operations associated with this domain.
 695 * @start: Called when a user needs to start the device via the domain.
 696 * @detach: Called when removing a device from the domain.
 697 * @activate: Called before executing probe routines for bus types and drivers.
 698 * @sync: Called after successful driver probe.
 699 * @dismiss: Called after unsuccessful driver probe and after driver removal.
 700 *
 701 * Power domains provide callbacks that are executed during system suspend,
 702 * hibernation, system resume and during runtime PM transitions instead of
 703 * subsystem-level and driver-level callbacks.
 704 */
 705struct dev_pm_domain {
 706        struct dev_pm_ops       ops;
 707        int (*start)(struct device *dev);
 708        void (*detach)(struct device *dev, bool power_off);
 709        int (*activate)(struct device *dev);
 710        void (*sync)(struct device *dev);
 711        void (*dismiss)(struct device *dev);
 712};
 713
 714/*
 715 * The PM_EVENT_ messages are also used by drivers implementing the legacy
 716 * suspend framework, based on the ->suspend() and ->resume() callbacks common
 717 * for suspend and hibernation transitions, according to the rules below.
 718 */
 719
 720/* Necessary, because several drivers use PM_EVENT_PRETHAW */
 721#define PM_EVENT_PRETHAW PM_EVENT_QUIESCE
 722
 723/*
 724 * One transition is triggered by resume(), after a suspend() call; the
 725 * message is implicit:
 726 *
 727 * ON           Driver starts working again, responding to hardware events
 728 *              and software requests.  The hardware may have gone through
 729 *              a power-off reset, or it may have maintained state from the
 730 *              previous suspend() which the driver will rely on while
 731 *              resuming.  On most platforms, there are no restrictions on
 732 *              availability of resources like clocks during resume().
 733 *
 734 * Other transitions are triggered by messages sent using suspend().  All
 735 * these transitions quiesce the driver, so that I/O queues are inactive.
 736 * That commonly entails turning off IRQs and DMA; there may be rules
 737 * about how to quiesce that are specific to the bus or the device's type.
 738 * (For example, network drivers mark the link state.)  Other details may
 739 * differ according to the message:
 740 *
 741 * SUSPEND      Quiesce, enter a low power device state appropriate for
 742 *              the upcoming system state (such as PCI_D3hot), and enable
 743 *              wakeup events as appropriate.
 744 *
 745 * HIBERNATE    Enter a low power device state appropriate for the hibernation
 746 *              state (eg. ACPI S4) and enable wakeup events as appropriate.
 747 *
 748 * FREEZE       Quiesce operations so that a consistent image can be saved;
 749 *              but do NOT otherwise enter a low power device state, and do
 750 *              NOT emit system wakeup events.
 751 *
 752 * PRETHAW      Quiesce as if for FREEZE; additionally, prepare for restoring
 753 *              the system from a snapshot taken after an earlier FREEZE.
 754 *              Some drivers will need to reset their hardware state instead
 755 *              of preserving it, to ensure that it's never mistaken for the
 756 *              state which that earlier snapshot had set up.
 757 *
 758 * A minimally power-aware driver treats all messages as SUSPEND, fully
 759 * reinitializes its device during resume() -- whether or not it was reset
 760 * during the suspend/resume cycle -- and can't issue wakeup events.
 761 *
 762 * More power-aware drivers may also use low power states at runtime as
 763 * well as during system sleep states like PM_SUSPEND_STANDBY.  They may
 764 * be able to use wakeup events to exit from runtime low-power states,
 765 * or from system low-power states such as standby or suspend-to-RAM.
 766 */
 767
 768#ifdef CONFIG_PM_SLEEP
 769extern void device_pm_lock(void);
 770extern void dpm_resume_start(pm_message_t state);
 771extern void dpm_resume_end(pm_message_t state);
 772extern void dpm_resume_noirq(pm_message_t state);
 773extern void dpm_resume_early(pm_message_t state);
 774extern void dpm_resume(pm_message_t state);
 775extern void dpm_complete(pm_message_t state);
 776
 777extern void device_pm_unlock(void);
 778extern int dpm_suspend_end(pm_message_t state);
 779extern int dpm_suspend_start(pm_message_t state);
 780extern int dpm_suspend_noirq(pm_message_t state);
 781extern int dpm_suspend_late(pm_message_t state);
 782extern int dpm_suspend(pm_message_t state);
 783extern int dpm_prepare(pm_message_t state);
 784
 785extern void __suspend_report_result(const char *function, struct device *dev, void *fn, int ret);
 786
 787#define suspend_report_result(dev, fn, ret)                             \
 788        do {                                                            \
 789                __suspend_report_result(__func__, dev, fn, ret);        \
 790        } while (0)
 791
 792extern int device_pm_wait_for_dev(struct device *sub, struct device *dev);
 793extern void dpm_for_each_dev(void *data, void (*fn)(struct device *, void *));
 794
 795extern int pm_generic_prepare(struct device *dev);
 796extern int pm_generic_suspend_late(struct device *dev);
 797extern int pm_generic_suspend_noirq(struct device *dev);
 798extern int pm_generic_suspend(struct device *dev);
 799extern int pm_generic_resume_early(struct device *dev);
 800extern int pm_generic_resume_noirq(struct device *dev);
 801extern int pm_generic_resume(struct device *dev);
 802extern int pm_generic_freeze_noirq(struct device *dev);
 803extern int pm_generic_freeze_late(struct device *dev);
 804extern int pm_generic_freeze(struct device *dev);
 805extern int pm_generic_thaw_noirq(struct device *dev);
 806extern int pm_generic_thaw_early(struct device *dev);
 807extern int pm_generic_thaw(struct device *dev);
 808extern int pm_generic_restore_noirq(struct device *dev);
 809extern int pm_generic_restore_early(struct device *dev);
 810extern int pm_generic_restore(struct device *dev);
 811extern int pm_generic_poweroff_noirq(struct device *dev);
 812extern int pm_generic_poweroff_late(struct device *dev);
 813extern int pm_generic_poweroff(struct device *dev);
 814extern void pm_generic_complete(struct device *dev);
 815
 816extern bool dev_pm_skip_resume(struct device *dev);
 817extern bool dev_pm_skip_suspend(struct device *dev);
 818
 819#else /* !CONFIG_PM_SLEEP */
 820
 821#define device_pm_lock() do {} while (0)
 822#define device_pm_unlock() do {} while (0)
 823
 824static inline int dpm_suspend_start(pm_message_t state)
 825{
 826        return 0;
 827}
 828
 829#define suspend_report_result(dev, fn, ret)     do {} while (0)
 830
 831static inline int device_pm_wait_for_dev(struct device *a, struct device *b)
 832{
 833        return 0;
 834}
 835
 836static inline void dpm_for_each_dev(void *data, void (*fn)(struct device *, void *))
 837{
 838}
 839
 840#define pm_generic_prepare              NULL
 841#define pm_generic_suspend_late         NULL
 842#define pm_generic_suspend_noirq        NULL
 843#define pm_generic_suspend              NULL
 844#define pm_generic_resume_early         NULL
 845#define pm_generic_resume_noirq         NULL
 846#define pm_generic_resume               NULL
 847#define pm_generic_freeze_noirq         NULL
 848#define pm_generic_freeze_late          NULL
 849#define pm_generic_freeze               NULL
 850#define pm_generic_thaw_noirq           NULL
 851#define pm_generic_thaw_early           NULL
 852#define pm_generic_thaw                 NULL
 853#define pm_generic_restore_noirq        NULL
 854#define pm_generic_restore_early        NULL
 855#define pm_generic_restore              NULL
 856#define pm_generic_poweroff_noirq       NULL
 857#define pm_generic_poweroff_late        NULL
 858#define pm_generic_poweroff             NULL
 859#define pm_generic_complete             NULL
 860#endif /* !CONFIG_PM_SLEEP */
 861
 862/* How to reorder dpm_list after device_move() */
 863enum dpm_order {
 864        DPM_ORDER_NONE,
 865        DPM_ORDER_DEV_AFTER_PARENT,
 866        DPM_ORDER_PARENT_BEFORE_DEV,
 867        DPM_ORDER_DEV_LAST,
 868};
 869
 870#endif /* _LINUX_PM_H */
 871