/*
* pm.h - Power management interface
*
* Copyright (C) 2000 Andrew Henroid
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef _LINUX_PM_H
#define _LINUX_PM_H
#include <linux/list.h>
/*
* Callbacks for platform drivers to implement.
*/
extern void (*pm_idle)(void);
extern void (*pm_power_off)(void);
extern void (*pm_power_off_prepare)(void);
/*
* Device power management
*/
struct device;
typedef struct pm_message {
int event;
} pm_message_t;
/**
* struct pm_ops - device PM callbacks
*
* Several driver power state transitions are externally visible, affecting
* the state of pending I/O queues and (for drivers that touch hardware)
* interrupts, wakeups, DMA, and other hardware state. There may also be
* internal transitions to various low power modes, which are transparent
* to the rest of the driver stack (such as a driver that's ON gating off
* clocks which are not in active use).
*
* The externally visible transitions are handled with the help of the following
* callbacks included in this structure:
*
* @prepare: Prepare the device for the upcoming transition, but do NOT change
* its hardware state. Prevent new children of the device from being
* registered after @prepare() returns (the driver's subsystem and
* generally the rest of the kernel is supposed to prevent new calls to the
* probe method from being made too once @prepare() has succeeded). If
* @prepare() detects a situation it cannot handle (e.g. registration of a
* child already in progress), it may return -EAGAIN, so that the PM core
* can execute it once again (e.g. after the new child has been registered)
* to recover from the race condition. This method is executed for all
* kinds of suspend transitions and is followed by one of the suspend
* callbacks: @suspend(), @freeze(), or @poweroff().
* The PM core executes @prepare() for all devices before starting to
* execute suspend callbacks for any of them, so drivers may assume all of
* the other devices to be present and functional while @prepare() is being
* executed. In particular, it is safe to make GFP_KERNEL memory
* allocations from within @prepare(). However, drivers may NOT assume
* anything about the availability of the user space at that time and it
* is not correct to request firmware from within @prepare() (it's too
* late to do that). [To work around this limitation, drivers may
* register suspend and hibernation notifiers that are executed before the
* freezing of tasks.]
*
* @complete: Undo the changes made by @prepare(). This method is executed for
* all kinds of resume transitions, following one of the resume callbacks:
* @resume(), @thaw(), @restore(). Also called if the state transition
* fails before the driver's suspend callback (@suspend(), @freeze(),
* @poweroff()) can be executed (e.g. if the suspend callback fails for one
* of the other devices that the PM core has unsuccessfully attempted to
* suspend earlier).
* The PM core executes @complete() after it has executed the appropriate
* resume callback for all devices.
*
* @suspend: Executed before putting the system into a sleep state in which the
* contents of main memory are preserved. Quiesce the device, put it into
* a low power state appropriate for the upcoming system state (such as
* PCI_D3hot), and enable wakeup events as appropriate.
*
* @resume: Executed after waking the system up from a sleep state in which the
* contents of main memory were preserved. Put the device into the
* appropriate state, according to the information saved in memory by the
* preceding @suspend(). The driver starts working again, responding to
* hardware events and software requests. The hardware may have gone
* through a power-off reset, or it may have maintained state from the
* previous suspend() which the driver may rely on while resuming. On most
* platforms, there are no restrictions on availability of resources like
* clocks during @resume().
*
* @freeze: Hibernation-specific, executed before creating a hibernation image.
* Quiesce operations so that a consistent image can be created, but do NOT
* otherwise put the device into a low power device state and do NOT emit
* system wakeup events. Save in main memory the device settings to be
* used by @restore() during the subsequent resume from hibernation or by
* the subsequent @thaw(), if the creation of the image or the restoration
* of main memory contents from it fails.
*
* @thaw: Hibernation-specific, executed after creating a hibernation image OR
* if the creation of the image fails. Also executed after a failing
* attempt to restore the contents of main memory from such an image.
* Undo the changes made by the preceding @freeze(), so the device can be
* operated in the same way as immediately before the call to @freeze().
*
* @poweroff: Hibernation-specific, executed after saving a hibernation image.
* Quiesce the device, put it into a low power state appropriate for the
* upcoming system state (such as PCI_D3hot), and enable wakeup events as
* appropriate.
*
* @restore: Hibernation-specific, executed after restoring the contents of main
* memory from a hibernation image. Driver starts working again,
* responding to hardware events and software requests. Drivers may NOT
* make ANY assumptions about the hardware state right prior to @restore().
* On most platforms, there are no restrictions on availability of
* resources like clocks during @restore().
*
* All of the above callbacks, except for @complete(), return error codes.
* However, the error codes returned by the resume operations, @resume(),
* @thaw(), and @restore(), do not cause the PM core to abort the resume
* transition during which they are returned. The error codes returned in
* that cases are only printed by the PM core to the system logs for debugging
* purposes. Still, it is recommended that drivers only return error codes
* from their resume methods in case of an unrecoverable failure (i.e. when the
* device being handled refuses to resume and becomes unusable) to allow us to
* modify the PM core in the future, so that it can avoid attempting to handle
* devices that failed to resume and their children.
*
* It is allowed to unregister devices while the above callbacks are being
* executed. However, it is not allowed to unregister a device from within any
* of its own callbacks.
*/
struct pm_ops {
int (*prepare)(struct device *dev);
void (*complete)(struct device *dev);
int (*suspend)(struct device *dev);
int (*resume)(struct device *dev);
int (*freeze)(struct device *dev);
int (*thaw)(struct device *dev);
int (*poweroff)(struct device *dev);
int (*restore)(struct device *dev);
};
/**
* struct pm_ext_ops - extended device PM callbacks
*
* Some devices require certain operations related to suspend and hibernation
* to be carried out with interrupts disabled. Thus, 'struct pm_ext_ops' below
* is defined, adding callbacks to be executed with interrupts disabled to
* 'struct pm_ops'.
*
* The following callbacks included in 'struct pm_ext_ops' are executed with
* the nonboot CPUs switched off and with interrupts disabled on the only
* functional CPU. They also are executed with the PM core list of devices
* locked, so they must NOT unregister any devices.
*
* @suspend_noirq: Complete the operations of ->suspend() by carrying out any
* actions required for suspending the device that need interrupts to be
* disabled
*
* @resume_noirq: Prepare for the execution of ->resume() by carrying out any
* actions required for resuming the device that need interrupts to be
* disabled
*
* @freeze_noirq: Complete the operations of ->freeze() by carrying out any
* actions required for freezing the device that need interrupts to be
* disabled
*
* @thaw_noirq: Prepare for the execution of ->thaw() by carrying out any
* actions required for thawing the device that need interrupts to be
* disabled
*
* @poweroff_noirq: Complete the operations of ->poweroff() by carrying out any
* actions required for handling the device that need interrupts to be
* disabled
*
* @restore_noirq: Prepare for the execution of ->restore() by carrying out any
* actions required for restoring the operations of the device that need
* interrupts to be disabled
*
* All of the above callbacks return error codes, but the error codes returned
* by the resume operations, @resume_noirq(), @thaw_noirq(), and
* @restore_noirq(), do not cause the PM core to abort the resume transition
* during which they are returned. The error codes returned in that cases are
* only printed by the PM core to the system logs for debugging purposes.
* Still, as stated above, it is recommended that drivers only return error
* codes from their resume methods if the device being handled fails to resume
* and is not usable any more.
*/
struct pm_ext_ops {
struct pm_ops base;
int (*suspend_noirq)(struct device *dev);
int (*resume_noirq)(struct device *dev);
int (*freeze_noirq)(struct device *dev);
int (*thaw_noirq)(struct device *dev);
int (*poweroff_noirq)(struct device *dev);
int (*restore_noirq)(struct device *dev);
};
/**
* PM_EVENT_ messages
*
* The following PM_EVENT_ messages are defined for the internal use of the PM
* core, in order to provide a mechanism allowing the high level suspend and
* hibernation code to convey the necessary information to the device PM core
* code:
*
* ON No transition.
*
* FREEZE System is going to hibernate, call ->prepare() and ->freeze()
* for all devices.
*
* SUSPEND System is going to suspend, call ->prepare() and ->suspend()
* for all devices.
*
* HIBERNATE Hibernation image has been saved, call ->prepare() and
* ->poweroff() for all devices.
*
* QUIESCE Contents of main memory are going to be restored from a (loaded)
* hibernation image, call ->prepare() and ->freeze() for all
* devices.
*
* RESUME System is resuming, call ->resume() and ->complete() for all
* devices.
*
* THAW Hibernation image has been created, call ->thaw() and
* ->complete() for all devices.
*
* RESTORE Contents of main memory have been restored from a hibernation
* image, call ->restore() and ->complete() for all devices.
*
* RECOVER Creation of a hibernation image or restoration of the main
* memory contents from a hibernation image has failed, call
* ->thaw() and ->complete() for all devices.
*/
#define PM_EVENT_ON 0x0000
#define PM_EVENT_FREEZE 0x0001
#define PM_EVENT_SUSPEND 0x0002
#define PM_EVENT_HIBERNATE 0x0004
#define PM_EVENT_QUIESCE 0x0008
#define PM_EVENT_RESUME 0x0010
#define PM_EVENT_THAW 0x0020
#define PM_EVENT_RESTORE 0x0040
#define PM_EVENT_RECOVER 0x0080
#define PM_EVENT_SLEEP (PM_EVENT_SUSPEND | PM_EVENT_HIBERNATE)
#define PMSG_FREEZE ((struct pm_message){ .event = PM_EVENT_FREEZE, })
#define PMSG_QUIESCE ((struct pm_message){ .event = PM_EVENT_QUIESCE, })
#define PMSG_SUSPEND ((struct pm_message){ .event = PM_EVENT_SUSPEND, })
#define PMSG_HIBERNATE ((struct pm_message){ .event = PM_EVENT_HIBERNATE, })
#define PMSG_RESUME ((struct pm_message){ .event = PM_EVENT_RESUME, })
#define PMSG_THAW ((struct pm_message){ .event = PM_EVENT_THAW, })
#define PMSG_RESTORE ((struct pm_message){ .event = PM_EVENT_RESTORE, })
#define PMSG_RECOVER ((struct pm_message){ .event = PM_EVENT_RECOVER, })
#define PMSG_ON ((struct pm_message){ .event = PM_EVENT_ON, })
/**
* Device power management states
*
* These state labels are used internally by the PM core to indicate the current
* status of a device with respect to the PM core operations.
*
* DPM_ON Device is regarded as operational. Set this way
* initially and when ->complete() is about to be called.
* Also set when ->prepare() fails.
*
* DPM_PREPARING Device is going to be prepared for a PM transition. Set
* when ->prepare() is about to be called.
*
* DPM_RESUMING Device is going to be resumed. Set when ->resume(),
* ->thaw(), or ->restore() is about to be called.
*
* DPM_SUSPENDING Device has been prepared for a power transition. Set
* when ->prepare() has just succeeded.
*
* DPM_OFF Device is regarded as inactive. Set immediately after
* ->suspend(), ->freeze(), or ->poweroff() has succeeded.
* Also set when ->resume()_noirq, ->thaw_noirq(), or
* ->restore_noirq() is about to be called.
*
* DPM_OFF_IRQ Device is in a "deep sleep". Set immediately after
* ->suspend_noirq(), ->freeze_noirq(), or
* ->poweroff_noirq() has just succeeded.
*/
enum dpm_state {
DPM_INVALID,
DPM_ON,
DPM_PREPARING,
DPM_RESUMING,
DPM_SUSPENDING,
DPM_OFF,
DPM_OFF_IRQ,
};
struct dev_pm_info {
pm_message_t power_state;
unsigned can_wakeup:1;
unsigned should_wakeup:1;
enum dpm_state status; /* Owned by the PM core */
#ifdef CONFIG_PM_SLEEP
struct list_head entry;
#endif
};
/*
* The PM_EVENT_ messages are also used by drivers implementing the legacy
* suspend framework, based on the ->suspend() and ->resume() callbacks common
* for suspend and hibernation transitions, according to the rules below.
*/
/* Necessary, because several drivers use PM_EVENT_PRETHAW */
#define PM_EVENT_PRETHAW PM_EVENT_QUIESCE
/*
* One transition is triggered by resume(), after a suspend() call; the
* message is implicit:
*
* ON Driver starts working again, responding to hardware events
* and software requests. The hardware may have gone through
* a power-off reset, or it may have maintained state from the
* previous suspend() which the driver will rely on while
* resuming. On most platforms, there are no restrictions on
* availability of resources like clocks during resume().
*
* Other transitions are triggered by messages sent using suspend(). All
* these transitions quiesce the driver, so that I/O queues are inactive.
* That commonly entails turning off IRQs and DMA; there may be rules
* about how to quiesce that are specific to the bus or the device's type.
* (For example, network drivers mark the link state.) Other details may
* differ according to the message:
*
* SUSPEND Quiesce, enter a low power device state appropriate for
* the upcoming system state (such as PCI_D3hot), and enable
* wakeup events as appropriate.
*
* HIBERNATE Enter a low power device state appropriate for the hibernation
* state (eg. ACPI S4) and enable wakeup events as appropriate.
*
* FREEZE Quiesce operations so that a consistent image can be saved;
* but do NOT otherwise enter a low power device state, and do
* NOT emit system wakeup events.
*
* PRETHAW Quiesce as if for FREEZE; additionally, prepare for restoring
* the system from a snapshot taken after an earlier FREEZE.
* Some drivers will need to reset their hardware state instead
* of preserving it, to ensure that it's never mistaken for the
* state which that earlier snapshot had set up.
*
* A minimally power-aware driver treats all messages as SUSPEND, fully
* reinitializes its device during resume() -- whether or not it was reset
* during the suspend/resume cycle -- and can't issue wakeup events.
*
* More power-aware drivers may also use low power states at runtime as
* well as during system sleep states like PM_SUSPEND_STANDBY. They may
* be able to use wakeup events to exit from runtime low-power states,
* or from system low-power states such as standby or suspend-to-RAM.
*/
#ifdef CONFIG_PM_SLEEP
extern void device_pm_lock(void);
extern void device_power_up(pm_message_t state);
extern void device_resume(pm_message_t state);
extern void device_pm_unlock(void);
extern int device_power_down(pm_message_t state);
extern int device_suspend(pm_message_t state);
extern int device_prepare_suspend(pm_message_t state);
extern void __suspend_report_result(const char *function, void *fn, int ret);
#define suspend_report_result(fn, ret) \
do { \
__suspend_report_result(__FUNCTION__, fn, ret); \
} while (0)
#else /* !CONFIG_PM_SLEEP */
static inline int device_suspend(pm_message_t state)
{
return 0;
}
#define suspend_report_result(fn, ret) do {} while (0)
#endif /* !CONFIG_PM_SLEEP */
/*
* Global Power Management flags
* Used to keep APM and ACPI from both being active
*/
extern unsigned int pm_flags;
#define PM_APM 1
#define PM_ACPI 2
#endif /* _LINUX_PM_H */
