diff options
Diffstat (limited to 'include/linux/pm.h')
| -rw-r--r-- | include/linux/pm.h | 62 |
1 files changed, 47 insertions, 15 deletions
diff --git a/include/linux/pm.h b/include/linux/pm.h index 87545e0f0b58..b2c4fde4e994 100644 --- a/include/linux/pm.h +++ b/include/linux/pm.h @@ -110,37 +110,67 @@ typedef int __bitwise suspend_state_t; #define PM_SUSPEND_MAX ((__force suspend_state_t) 4) /** - * struct pm_ops - Callbacks for managing platform dependent suspend states. - * @valid: Callback to determine whether the given state can be entered. - * Valid states are advertised in /sys/power/state but can still - * be rejected by prepare or enter if the conditions aren't right. - * There is a %pm_valid_only_mem function available that can be assigned - * to this if you only implement mem sleep. + * struct pm_ops - Callbacks for managing platform dependent system sleep + * states. * - * @prepare: Prepare the platform for the given suspend state. Can return a - * negative error code if necessary. + * @valid: Callback to determine if given system sleep state is supported by + * the platform. + * Valid (ie. supported) states are advertised in /sys/power/state. Note + * that it still may be impossible to enter given system sleep state if the + * conditions aren't right. + * There is the %pm_valid_only_mem function available that can be assigned + * to this if the platform only supports mem sleep. * - * @enter: Enter the given suspend state, must be assigned. Can return a - * negative error code if necessary. + * @set_target: Tell the platform which system sleep state is going to be + * entered. + * @set_target() is executed right prior to suspending devices. The + * information conveyed to the platform code by @set_target() should be + * disregarded by the platform as soon as @finish() is executed and if + * @prepare() fails. If @set_target() fails (ie. returns nonzero), + * @prepare(), @enter() and @finish() will not be called by the PM core. + * This callback is optional. However, if it is implemented, the argument + * passed to @prepare(), @enter() and @finish() is meaningless and should + * be ignored. * - * @finish: Called when the system has left the given state and all devices - * are resumed. The return value is ignored. + * @prepare: Prepare the platform for entering the system sleep state indicated + * by @set_target() or represented by the argument if @set_target() is not + * implemented. + * @prepare() is called right after devices have been suspended (ie. the + * appropriate .suspend() method has been executed for each device) and + * before the nonboot CPUs are disabled (it is executed with IRQs enabled). + * This callback is optional. It returns 0 on success or a negative + * error code otherwise, in which case the system cannot enter the desired + * sleep state (@enter() and @finish() will not be called in that case). + * + * @enter: Enter the system sleep state indicated by @set_target() or + * represented by the argument if @set_target() is not implemented. + * This callback is mandatory. It returns 0 on success or a negative + * error code otherwise, in which case the system cannot enter the desired + * sleep state. + * + * @finish: Called when the system has just left a sleep state, right after + * the nonboot CPUs have been enabled and before devices are resumed (it is + * executed with IRQs enabled). If @set_target() is not implemented, the + * argument represents the sleep state being left. + * This callback is optional, but should be implemented by the platforms + * that implement @prepare(). If implemented, it is always called after + * @enter() (even if @enter() fails). */ struct pm_ops { int (*valid)(suspend_state_t state); + int (*set_target)(suspend_state_t state); int (*prepare)(suspend_state_t state); int (*enter)(suspend_state_t state); int (*finish)(suspend_state_t state); }; +extern struct pm_ops *pm_ops; + /** * pm_set_ops - set platform dependent power management ops * @pm_ops: The new power management operations to set. */ extern void pm_set_ops(struct pm_ops *pm_ops); -extern struct pm_ops *pm_ops; -extern int pm_suspend(suspend_state_t state); - extern int pm_valid_only_mem(suspend_state_t state); /** @@ -161,6 +191,8 @@ extern void arch_suspend_disable_irqs(void); */ extern void arch_suspend_enable_irqs(void); +extern int pm_suspend(suspend_state_t state); + /* * Device power management */ |