/* * 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 dev_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(). * * @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, except for @complete(), return error codes. * However, the error codes returned by the resume operations, @resume(), * @thaw(), @restore(), @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, 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 dev_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); 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. * * The following PM_EVENT_ messages are defined for internal use by * kernel subsystems. They are never issued by the PM core. * * USER_SUSPEND Manual selective suspend was issued by userspace. * * USER_RESUME Manual selective resume was issued by userspace. * * REMOTE_WAKEUP Remote-wakeup request was received from the device. * * AUTO_SUSPEND Automatic (device idle) runtime suspend was * initiated by the subsystem. * * AUTO_RESUME Automatic (device needed) runtime resume was * requested by a driver. */ #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_USER 0x0100 #define PM_EVENT_REMOTE 0x0200 #define PM_EVENT_AUTO 0x0400 #define PM_EVENT_SLEEP (PM_EVENT_SUSPEND | PM_EVENT_HIBERNATE) #define PM_EVENT_USER_SUSPEND (PM_EVENT_USER | PM_EVENT_SUSPEND) #define PM_EVENT_USER_RESUME (PM_EVENT_USER | PM_EVENT_RESUME) #define PM_EVENT_REMOTE_RESUME (PM_EVENT_REMOTE | PM_EVENT_RESUME) #define PM_EVENT_AUTO_SUSPEND (PM_EVENT_AUTO | PM_EVENT_SUSPEND) #define PM_EVENT_AUTO_RESUME (PM_EVENT_AUTO | PM_EVENT_RESUME) #define PMSG_ON ((struct pm_message){ .event = PM_EVENT_ON, }) #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_USER_SUSPEND ((struct pm_message) \ { .event = PM_EVENT_USER_SUSPEND, }) #define PMSG_USER_RESUME ((struct pm_message) \ { .event = PM_EVENT_USER_RESUME, }) #define PMSG_REMOTE_RESUME ((struct pm_message) \ { .event = PM_EVENT_REMOTE_RESUME, }) #define PMSG_AUTO_SUSPEND ((struct pm_message) \ { .event = PM_EVENT_AUTO_SUSPEND, }) #define PMSG_AUTO_RESUME ((struct pm_message) \ { .event = PM_EVENT_AUTO_RESUME, }) /** * 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 int sysdev_resume(void); extern void dpm_resume_noirq(pm_message_t state); extern void dpm_resume_end(pm_message_t state); extern void device_pm_unlock(void); extern int sysdev_suspend(pm_message_t state); extern int dpm_suspend_noirq(pm_message_t state); extern int dpm_suspend_start(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(__func__, fn, ret); \ } while (0) #else /* !CONFIG_PM_SLEEP */ #define device_pm_lock() do {} while (0) #define device_pm_unlock() do {} while (0) static inline int dpm_suspend_start(pm_message_t state) { return 0; } #define suspend_report_result(fn, ret) do {} while (0) #endif /* !CONFIG_PM_SLEEP */ /* How to reorder dpm_list after device_move() */ enum dpm_order { DPM_ORDER_NONE, DPM_ORDER_DEV_AFTER_PARENT, DPM_ORDER_PARENT_BEFORE_DEV, DPM_ORDER_DEV_LAST, }; /* * 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 */