include/linux/pm.h

   1 /*
   2  *  pm.h - Power management interface
   3  *
   4  *  Copyright (C) 2000 Andrew Henroid
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation; either version 2 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program; if not, write to the Free Software
  18  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21 #ifndef _LINUX_PM_H
  22 #define _LINUX_PM_H
  23
  24 #include <linux/list.h>
  25 #include <asm/atomic.h>
  26 #include <asm/errno.h>
  27
  28 /*
  29  * Power management requests... these are passed to pm_send_all() and friends.
  30  *
  31  * these functions are old and deprecated, see below.
  32  */
  33 typedef int __bitwise pm_request_t;
  34
  35 #define PM_SUSPEND      ((__force pm_request_t) 1)      /* enter D1-D3 */
  36 #define PM_RESUME       ((__force pm_request_t) 2)      /* enter D0 */
  37
  38
  39 /*
  40  * Device types... these are passed to pm_register
  41  */
  42 typedef int __bitwise pm_dev_t;
  43
  44 #define PM_UNKNOWN_DEV  ((__force pm_dev_t) 0)  /* generic */
  45 #define PM_SYS_DEV      ((__force pm_dev_t) 1)  /* system device (fan, KB controller, ...) */
  46 #define PM_PCI_DEV      ((__force pm_dev_t) 2)  /* PCI device */
  47 #define PM_USB_DEV      ((__force pm_dev_t) 3)  /* USB device */
  48 #define PM_SCSI_DEV     ((__force pm_dev_t) 4)  /* SCSI device */
  49 #define PM_ISA_DEV      ((__force pm_dev_t) 5)  /* ISA device */
  50 #define PM_MTD_DEV      ((__force pm_dev_t) 6)  /* Memory Technology Device */
  51
  52 /*
  53  * System device hardware ID (PnP) values
  54  */
  55 enum
  56 {
  57         PM_SYS_UNKNOWN = 0x00000000, /* generic */
  58         PM_SYS_KBC =     0x41d00303, /* keyboard controller */
  59         PM_SYS_COM =     0x41d00500, /* serial port */
  60         PM_SYS_IRDA =    0x41d00510, /* IRDA controller */
  61         PM_SYS_FDC =     0x41d00700, /* floppy controller */
  62         PM_SYS_VGA =     0x41d00900, /* VGA controller */
  63         PM_SYS_PCMCIA =  0x41d00e00, /* PCMCIA controller */
  64 };
  65
  66 /*
  67  * Device identifier
  68  */
  69 #define PM_PCI_ID(dev) ((dev)->bus->number << 16 | (dev)->devfn)
  70
  71 /*
  72  * Request handler callback
  73  */
  74 struct pm_dev;
  75
  76 typedef int (*pm_callback)(struct pm_dev *dev, pm_request_t rqst, void *data);
  77
  78 /*
  79  * Dynamic device information
  80  */
  81 struct pm_dev
  82 {
  83         pm_dev_t         type;
  84         unsigned long    id;
  85         pm_callback      callback;
  86         void            *data;
  87
  88         unsigned long    flags;
  89         unsigned long    state;
  90         unsigned long    prev_state;
  91
  92         struct list_head entry;
  93 };
  94
  95 /* Functions above this comment are list-based old-style power
  96  * management. Please avoid using them.  */
  97
  98 /*
  99  * Callbacks for platform drivers to implement.
 100  */
 101 extern void (*pm_idle)(void);
 102 extern void (*pm_power_off)(void);
 103 extern void (*pm_power_off_prepare)(void);
 104
 105 /*
 106  * Device power management
 107  */
 108
 109 struct device;
 110
 111 typedef struct pm_message {
 112         int event;
 113 } pm_message_t;
 114
 115 /**
 116  * struct pm_ops - device PM callbacks
 117  *
 118  * Several driver power state transitions are externally visible, affecting
 119  * the state of pending I/O queues and (for drivers that touch hardware)
 120  * interrupts, wakeups, DMA, and other hardware state.  There may also be
 121  * internal transitions to various low power modes, which are transparent
 122  * to the rest of the driver stack (such as a driver that's ON gating off
 123  * clocks which are not in active use).
 124  *
 125  * The externally visible transitions are handled with the help of the following
 126  * callbacks included in this structure:
 127  *
 128  * @prepare: Prepare the device for the upcoming transition, but do NOT change
 129  *      its hardware state.  Prevent new children of the device from being
 130  *      registered after @prepare() returns (the driver's subsystem and
 131  *      generally the rest of the kernel is supposed to prevent new calls to the
 132  *      probe method from being made too once @prepare() has succeeded).  If
 133  *      @prepare() detects a situation it cannot handle (e.g. registration of a
 134  *      child already in progress), it may return -EAGAIN, so that the PM core
 135  *      can execute it once again (e.g. after the new child has been registered)
 136  *      to recover from the race condition.  This method is executed for all
 137  *      kinds of suspend transitions and is followed by one of the suspend
 138  *      callbacks: @suspend(), @freeze(), or @poweroff().
 139  *      The PM core executes @prepare() for all devices before starting to
 140  *      execute suspend callbacks for any of them, so drivers may assume all of
 141  *      the other devices to be present and functional while @prepare() is being
 142  *      executed.  In particular, it is safe to make GFP_KERNEL memory
 143  *      allocations from within @prepare().  However, drivers may NOT assume
 144  *      anything about the availability of the user space at that time and it
 145  *      is not correct to request firmware from within @prepare() (it's too
 146  *      late to do that).  [To work around this limitation, drivers may
 147  *      register suspend and hibernation notifiers that are executed before the
 148  *      freezing of tasks.]
 149  *
 150  * @complete: Undo the changes made by @prepare().  This method is executed for
 151  *      all kinds of resume transitions, following one of the resume callbacks:
 152  *      @resume(), @thaw(), @restore().  Also called if the state transition
 153  *      fails before the driver's suspend callback (@suspend(), @freeze(),
 154  *      @poweroff()) can be executed (e.g. if the suspend callback fails for one
 155  *      of the other devices that the PM core has unsuccessfully attempted to
 156  *      suspend earlier).
 157  *      The PM core executes @complete() after it has executed the appropriate
 158  *      resume callback for all devices.
 159  *
 160  * @suspend: Executed before putting the system into a sleep state in which the
 161  *      contents of main memory are preserved.  Quiesce the device, put it into
 162  *      a low power state appropriate for the upcoming system state (such as
 163  *      PCI_D3hot), and enable wakeup events as appropriate.
 164  *
 165  * @resume: Executed after waking the system up from a sleep state in which the
 166  *      contents of main memory were preserved.  Put the device into the
 167  *      appropriate state, according to the information saved in memory by the
 168  *      preceding @suspend().  The driver starts working again, responding to
 169  *      hardware events and software requests.  The hardware may have gone
 170  *      through a power-off reset, or it may have maintained state from the
 171  *      previous suspend() which the driver may rely on while resuming.  On most
 172  *      platforms, there are no restrictions on availability of resources like
 173  *      clocks during @resume().
 174  *
 175  * @freeze: Hibernation-specific, executed before creating a hibernation image.
 176  *      Quiesce operations so that a consistent image can be created, but do NOT
 177  *      otherwise put the device into a low power device state and do NOT emit
 178  *      system wakeup events.  Save in main memory the device settings to be
 179  *      used by @restore() during the subsequent resume from hibernation or by
 180  *      the subsequent @thaw(), if the creation of the image or the restoration
 181  *      of main memory contents from it fails.
 182  *
 183  * @thaw: Hibernation-specific, executed after creating a hibernation image OR
 184  *      if the creation of the image fails.  Also executed after a failing
 185  *      attempt to restore the contents of main memory from such an image.
 186  *      Undo the changes made by the preceding @freeze(), so the device can be
 187  *      operated in the same way as immediately before the call to @freeze().
 188  *
 189  * @poweroff: Hibernation-specific, executed after saving a hibernation image.
 190  *      Quiesce the device, put it into a low power state appropriate for the
 191  *      upcoming system state (such as PCI_D3hot), and enable wakeup events as
 192  *      appropriate.
 193  *
 194  * @restore: Hibernation-specific, executed after restoring the contents of main
 195  *      memory from a hibernation image.  Driver starts working again,
 196  *      responding to hardware events and software requests.  Drivers may NOT
 197  *      make ANY assumptions about the hardware state right prior to @restore().
 198  *      On most platforms, there are no restrictions on availability of
 199  *      resources like clocks during @restore().
 200  *
 201  * All of the above callbacks, except for @complete(), return error codes.
 202  * However, the error codes returned by the resume operations, @resume(),
 203  * @thaw(), and @restore(), do not cause the PM core to abort the resume
 204  * transition during which they are returned.  The error codes returned in
 205  * that cases are only printed by the PM core to the system logs for debugging
 206  * purposes.  Still, it is recommended that drivers only return error codes
 207  * from their resume methods in case of an unrecoverable failure (i.e. when the
 208  * device being handled refuses to resume and becomes unusable) to allow us to
 209  * modify the PM core in the future, so that it can avoid attempting to handle
 210  * devices that failed to resume and their children.
 211  *
 212  * It is allowed to unregister devices while the above callbacks are being
 213  * executed.  However, it is not allowed to unregister a device from within any
 214  * of its own callbacks.
 215  */
 216
 217 struct pm_ops {
 218         int (*prepare)(struct device *dev);
 219         void (*complete)(struct device *dev);
 220         int (*suspend)(struct device *dev);
 221         int (*resume)(struct device *dev);
 222         int (*freeze)(struct device *dev);
 223         int (*thaw)(struct device *dev);
 224         int (*poweroff)(struct device *dev);
 225         int (*restore)(struct device *dev);
 226 };
 227
 228 /**
 229  * struct pm_ext_ops - extended device PM callbacks
 230  *
 231  * Some devices require certain operations related to suspend and hibernation
 232  * to be carried out with interrupts disabled.  Thus, 'struct pm_ext_ops' below
 233  * is defined, adding callbacks to be executed with interrupts disabled to
 234  * 'struct pm_ops'.
 235  *
 236  * The following callbacks included in 'struct pm_ext_ops' are executed with
 237  * the nonboot CPUs switched off and with interrupts disabled on the only
 238  * functional CPU.  They also are executed with the PM core list of devices
 239  * locked, so they must NOT unregister any devices.
 240  *
 241  * @suspend_noirq: Complete the operations of ->suspend() by carrying out any
 242  *      actions required for suspending the device that need interrupts to be
 243  *      disabled
 244  *
 245  * @resume_noirq: Prepare for the execution of ->resume() by carrying out any
 246  *      actions required for resuming the device that need interrupts to be
 247  *      disabled
 248  *
 249  * @freeze_noirq: Complete the operations of ->freeze() by carrying out any
 250  *      actions required for freezing the device that need interrupts to be
 251  *      disabled
 252  *
 253  * @thaw_noirq: Prepare for the execution of ->thaw() by carrying out any
 254  *      actions required for thawing the device that need interrupts to be
 255  *      disabled
 256  *
 257  * @poweroff_noirq: Complete the operations of ->poweroff() by carrying out any
 258  *      actions required for handling the device that need interrupts to be
 259  *      disabled
 260  *
 261  * @restore_noirq: Prepare for the execution of ->restore() by carrying out any
 262  *      actions required for restoring the operations of the device that need
 263  *      interrupts to be disabled
 264  *
 265  * All of the above callbacks return error codes, but the error codes returned
 266  * by the resume operations, @resume_noirq(), @thaw_noirq(), and
 267  * @restore_noirq(), do not cause the PM core to abort the resume transition
 268  * during which they are returned.  The error codes returned in that cases are
 269  * only printed by the PM core to the system logs for debugging purposes.
 270  * Still, as stated above, it is recommended that drivers only return error
 271  * codes from their resume methods if the device being handled fails to resume
 272  * and is not usable any more.
 273  */
 274
 275 struct pm_ext_ops {
 276         struct pm_ops base;
 277         int (*suspend_noirq)(struct device *dev);
 278         int (*resume_noirq)(struct device *dev);
 279         int (*freeze_noirq)(struct device *dev);
 280         int (*thaw_noirq)(struct device *dev);
 281         int (*poweroff_noirq)(struct device *dev);
 282         int (*restore_noirq)(struct device *dev);
 283 };
 284
 285 /**
 286  * PM_EVENT_ messages
 287  *
 288  * The following PM_EVENT_ messages are defined for the internal use of the PM
 289  * core, in order to provide a mechanism allowing the high level suspend and
 290  * hibernation code to convey the necessary information to the device PM core
 291  * code:
 292  *
 293  * ON           No transition.
 294  *
 295  * FREEZE       System is going to hibernate, call ->prepare() and ->freeze()
 296  *              for all devices.
 297  *
 298  * SUSPEND      System is going to suspend, call ->prepare() and ->suspend()
 299  *              for all devices.
 300  *
 301  * HIBERNATE    Hibernation image has been saved, call ->prepare() and
 302  *              ->poweroff() for all devices.
 303  *
 304  * QUIESCE      Contents of main memory are going to be restored from a (loaded)
 305  *              hibernation image, call ->prepare() and ->freeze() for all
 306  *              devices.
 307  *
 308  * RESUME       System is resuming, call ->resume() and ->complete() for all
 309  *              devices.
 310  *
 311  * THAW         Hibernation image has been created, call ->thaw() and
 312  *              ->complete() for all devices.
 313  *
 314  * RESTORE      Contents of main memory have been restored from a hibernation
 315  *              image, call ->restore() and ->complete() for all devices.
 316  *
 317  * RECOVER      Creation of a hibernation image or restoration of the main
 318  *              memory contents from a hibernation image has failed, call
 319  *              ->thaw() and ->complete() for all devices.
 320  */
 321
 322 #define PM_EVENT_ON             0x0000
 323 #define PM_EVENT_FREEZE         0x0001
 324 #define PM_EVENT_SUSPEND        0x0002
 325 #define PM_EVENT_HIBERNATE      0x0004
 326 #define PM_EVENT_QUIESCE        0x0008
 327 #define PM_EVENT_RESUME         0x0010
 328 #define PM_EVENT_THAW           0x0020
 329 #define PM_EVENT_RESTORE        0x0040
 330 #define PM_EVENT_RECOVER        0x0080
 331
 332 #define PM_EVENT_SLEEP  (PM_EVENT_SUSPEND | PM_EVENT_HIBERNATE)
 333
 334 #define PMSG_FREEZE     ((struct pm_message){ .event = PM_EVENT_FREEZE, })
 335 #define PMSG_QUIESCE    ((struct pm_message){ .event = PM_EVENT_QUIESCE, })
 336 #define PMSG_SUSPEND    ((struct pm_message){ .event = PM_EVENT_SUSPEND, })
 337 #define PMSG_HIBERNATE  ((struct pm_message){ .event = PM_EVENT_HIBERNATE, })
 338 #define PMSG_RESUME     ((struct pm_message){ .event = PM_EVENT_RESUME, })
 339 #define PMSG_THAW       ((struct pm_message){ .event = PM_EVENT_THAW, })
 340 #define PMSG_RESTORE    ((struct pm_message){ .event = PM_EVENT_RESTORE, })
 341 #define PMSG_RECOVER    ((struct pm_message){ .event = PM_EVENT_RECOVER, })
 342 #define PMSG_ON         ((struct pm_message){ .event = PM_EVENT_ON, })
 343
 344 /**
 345  * Device power management states
 346  *
 347  * These state labels are used internally by the PM core to indicate the current
 348  * status of a device with respect to the PM core operations.
 349  *
 350  * DPM_ON               Device is regarded as operational.  Set this way
 351  *                      initially and when ->complete() is about to be called.
 352  *                      Also set when ->prepare() fails.
 353  *
 354  * DPM_PREPARING        Device is going to be prepared for a PM transition.  Set
 355  *                      when ->prepare() is about to be called.
 356  *
 357  * DPM_RESUMING         Device is going to be resumed.  Set when ->resume(),
 358  *                      ->thaw(), or ->restore() is about to be called.
 359  *
 360  * DPM_SUSPENDING       Device has been prepared for a power transition.  Set
 361  *                      when ->prepare() has just succeeded.
 362  *
 363  * DPM_OFF              Device is regarded as inactive.  Set immediately after
 364  *                      ->suspend(), ->freeze(), or ->poweroff() has succeeded.
 365  *                      Also set when ->resume()_noirq, ->thaw_noirq(), or
 366  *                      ->restore_noirq() is about to be called.
 367  *
 368  * DPM_OFF_IRQ          Device is in a "deep sleep".  Set immediately after
 369  *                      ->suspend_noirq(), ->freeze_noirq(), or
 370  *                      ->poweroff_noirq() has just succeeded.
 371  */
 372
 373 enum dpm_state {
 374         DPM_INVALID,
 375         DPM_ON,
 376         DPM_PREPARING,
 377         DPM_RESUMING,
 378         DPM_SUSPENDING,
 379         DPM_OFF,
 380         DPM_OFF_IRQ,
 381 };
 382
 383 struct dev_pm_info {
 384         pm_message_t            power_state;
 385         unsigned                can_wakeup:1;
 386         unsigned                should_wakeup:1;
 387         enum dpm_state          status;         /* Owned by the PM core */
 388 #ifdef  CONFIG_PM_SLEEP
 389         struct list_head        entry;
 390 #endif
 391 };
 392
 393 /*
 394  * The PM_EVENT_ messages are also used by drivers implementing the legacy
 395  * suspend framework, based on the ->suspend() and ->resume() callbacks common
 396  * for suspend and hibernation transitions, according to the rules below.
 397  */
 398
 399 /* Necessary, because several drivers use PM_EVENT_PRETHAW */
 400 #define PM_EVENT_PRETHAW PM_EVENT_QUIESCE
 401
 402 /*
 403  * One transition is triggered by resume(), after a suspend() call; the
 404  * message is implicit:
 405  *
 406  * ON           Driver starts working again, responding to hardware events
 407  *              and software requests.  The hardware may have gone through
 408  *              a power-off reset, or it may have maintained state from the
 409  *              previous suspend() which the driver will rely on while
 410  *              resuming.  On most platforms, there are no restrictions on
 411  *              availability of resources like clocks during resume().
 412  *
 413  * Other transitions are triggered by messages sent using suspend().  All
 414  * these transitions quiesce the driver, so that I/O queues are inactive.
 415  * That commonly entails turning off IRQs and DMA; there may be rules
 416  * about how to quiesce that are specific to the bus or the device's type.
 417  * (For example, network drivers mark the link state.)  Other details may
 418  * differ according to the message:
 419  *
 420  * SUSPEND      Quiesce, enter a low power device state appropriate for
 421  *              the upcoming system state (such as PCI_D3hot), and enable
 422  *              wakeup events as appropriate.
 423  *
 424  * HIBERNATE    Enter a low power device state appropriate for the hibernation
 425  *              state (eg. ACPI S4) and enable wakeup events as appropriate.
 426  *
 427  * FREEZE       Quiesce operations so that a consistent image can be saved;
 428  *              but do NOT otherwise enter a low power device state, and do
 429  *              NOT emit system wakeup events.
 430  *
 431  * PRETHAW      Quiesce as if for FREEZE; additionally, prepare for restoring
 432  *              the system from a snapshot taken after an earlier FREEZE.
 433  *              Some drivers will need to reset their hardware state instead
 434  *              of preserving it, to ensure that it's never mistaken for the
 435  *              state which that earlier snapshot had set up.
 436  *
 437  * A minimally power-aware driver treats all messages as SUSPEND, fully
 438  * reinitializes its device during resume() -- whether or not it was reset
 439  * during the suspend/resume cycle -- and can't issue wakeup events.
 440  *
 441  * More power-aware drivers may also use low power states at runtime as
 442  * well as during system sleep states like PM_SUSPEND_STANDBY.  They may
 443  * be able to use wakeup events to exit from runtime low-power states,
 444  * or from system low-power states such as standby or suspend-to-RAM.
 445  */
 446
 447 #ifdef CONFIG_PM_SLEEP
 448 extern void device_pm_lock(void);
 449 extern void device_power_up(pm_message_t state);
 450 extern void device_resume(pm_message_t state);
 451
 452 extern void device_pm_unlock(void);
 453 extern int device_power_down(pm_message_t state);
 454 extern int device_suspend(pm_message_t state);
 455 extern int device_prepare_suspend(pm_message_t state);
 456
 457 extern void __suspend_report_result(const char *function, void *fn, int ret);
 458
 459 #define suspend_report_result(fn, ret)                                  \
 460         do {                                                            \
 461                 __suspend_report_result(__FUNCTION__, fn, ret);         \
 462         } while (0)
 463
 464 #else /* !CONFIG_PM_SLEEP */
 465
 466 static inline int device_suspend(pm_message_t state)
 467 {
 468         return 0;
 469 }
 470
 471 #define suspend_report_result(fn, ret)          do {} while (0)
 472
 473 #endif /* !CONFIG_PM_SLEEP */
 474
 475 /*
 476  * Global Power Management flags
 477  * Used to keep APM and ACPI from both being active
 478  */
 479 extern unsigned int     pm_flags;
 480
 481 #define PM_APM  1
 482 #define PM_ACPI 2
 483
 484 #endif /* _LINUX_PM_H */