Add an optional platform_suspend_ops callback: target_state, and a helper function globally visible to get this called: platform_suspend_target_state().
This is useful for platform specific drivers that may need to take a slightly different suspend/resume path based on the system's suspend/resume state being entered. Although this callback is optional and documented as such, it requires a platform_suspend_ops::begin callback to be implemented in order to provide an accurate suspend/resume state within the driver that implements this platform_suspend_ops. An enumeration: platform_target_state is defined which currently defines the standard ACPI_S[1-4] states and can be extended with platform specific suspend states. Signed-off-by: Florian Fainelli <[email protected]> --- include/linux/suspend.h | 25 +++++++++++++++++++++++++ kernel/power/suspend.c | 15 +++++++++++++++ 2 files changed, 40 insertions(+) diff --git a/include/linux/suspend.h b/include/linux/suspend.h index 0b1cf32edfd7..6e6cc0778816 100644 --- a/include/linux/suspend.h +++ b/include/linux/suspend.h @@ -50,6 +50,16 @@ enum suspend_stat_step { SUSPEND_RESUME }; +enum platform_target_state { + PLATFORM_STATE_UNKNOWN = -1, + PLATFORM_STATE_WORKING = 0, + PLATFORM_STATE_ACPI_S1, + PLATFORM_STATE_ACPI_S2, + PLATFORM_STATE_ACPI_S3, + PLATFORM_STATE_ACPI_S4, + /* Add platform specific states here */ +}; + struct suspend_stats { int success; int fail; @@ -172,6 +182,15 @@ static inline void dpm_save_failed_step(enum suspend_stat_step step) * Called by the PM core if the suspending of devices fails. * This callback is optional and should only be implemented by platforms * which require special recovery actions in that situation. + * + * @target_state: Returns the suspend state the suspend_ops will be entering. + * Called by device drivers that need to know the platform specific suspend + * state the system is about to enter. + * This callback is optional and should only be implemented by platforms + * which require special handling of power management states within + * drivers. It does require @begin to be implemented to provide the suspend + * state. Return value is platform_suspend_ops specific, and may be a 1:1 + * mapping to suspend_state_t when relevant. */ struct platform_suspend_ops { int (*valid)(suspend_state_t state); @@ -184,6 +203,7 @@ struct platform_suspend_ops { bool (*suspend_again)(void); void (*end)(void); void (*recover)(void); + enum platform_target_state (*target_state)(void); }; struct platform_freeze_ops { @@ -202,6 +222,7 @@ struct platform_freeze_ops { */ extern void suspend_set_ops(const struct platform_suspend_ops *ops); extern int suspend_valid_only_mem(suspend_state_t state); +extern enum platform_target_state platform_suspend_target_state(void); extern unsigned int pm_suspend_global_flags; @@ -281,6 +302,10 @@ static inline bool pm_resume_via_firmware(void) { return false; } static inline void suspend_set_ops(const struct platform_suspend_ops *ops) {} static inline int pm_suspend(suspend_state_t state) { return -ENOSYS; } +static inline int platform_suspend_target_state(void) +{ + return PLATFORM_STATE_UNKNOWN; +} static inline bool idle_should_freeze(void) { return false; } static inline void __init pm_states_init(void) {} static inline void freeze_set_ops(const struct platform_freeze_ops *ops) {} diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c index 3ecf275d7e44..cd1b62f23b0e 100644 --- a/kernel/power/suspend.c +++ b/kernel/power/suspend.c @@ -202,6 +202,21 @@ void suspend_set_ops(const struct platform_suspend_ops *ops) EXPORT_SYMBOL_GPL(suspend_set_ops); /** + * platform_suspend_target_state - Return the platform specific suspend state. + * a begin() callback is necessary in order to fill this information correctly + * for callers. + */ +enum platform_target_state platform_suspend_target_state(void) +{ + if (!suspend_ops || !suspend_ops->target_state || + (suspend_ops->target_state && !suspend_ops->begin)) + return -ENOTSUPP; + + return suspend_ops->target_state(); +} +EXPORT_SYMBOL_GPL(platform_suspend_target_state); + +/** * suspend_valid_only_mem - Generic memory-only valid callback. * * Platform drivers that implement mem suspend only and only need to check for -- 2.9.3
