From d4f8138354b9ec290de0c7ba527a945c5549e32b Mon Sep 17 00:00:00 2001 From: Ulf Hansson Date: Tue, 13 Oct 2020 14:23:39 +0200 Subject: PM: domains: Add support for PM domain on/off notifiers for genpd A device may have specific HW constraints that must be obeyed to, before its corresponding PM domain (genpd) can be powered off - and vice verse at power on. These constraints can't be managed through the regular runtime PM based deployment for a device, because the access pattern for it, isn't always request based. In other words, using the runtime PM callbacks to deal with the constraints doesn't work for these cases. For these reasons, let's instead add a PM domain power on/off notification mechanism to genpd. To add/remove a notifier for a device, the device must already have been attached to the genpd, which also means that it needs to be a part of the PM domain topology. To add/remove a notifier, let's introduce two genpd specific functions: - dev_pm_genpd_add|remove_notifier() Note that, to further clarify when genpd power on/off notifiers may be used, one can compare with the existing CPU_CLUSTER_PM_ENTER|EXIT notifiers. In the long run, the genpd power on/off notifiers should be able to replace them, but that requires additional genpd based platform support for the current users. Signed-off-by: Ulf Hansson Tested-by: Lina Iyer Signed-off-by: Rafael J. Wysocki --- include/linux/pm_domain.h | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) (limited to 'include/linux/pm_domain.h') diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h index 66f3c5d64d81..db039da0aba2 100644 --- a/include/linux/pm_domain.h +++ b/include/linux/pm_domain.h @@ -68,6 +68,13 @@ enum gpd_status { GENPD_STATE_OFF, /* PM domain is off */ }; +enum genpd_notication { + GENPD_NOTIFY_PRE_OFF = 0, + GENPD_NOTIFY_OFF, + GENPD_NOTIFY_PRE_ON, + GENPD_NOTIFY_ON, +}; + struct dev_power_governor { bool (*power_down_ok)(struct dev_pm_domain *domain); bool (*suspend_ok)(struct device *dev); @@ -112,6 +119,7 @@ struct generic_pm_domain { cpumask_var_t cpus; /* A cpumask of the attached CPUs */ int (*power_off)(struct generic_pm_domain *domain); int (*power_on)(struct generic_pm_domain *domain); + struct raw_notifier_head power_notifiers; /* Power on/off notifiers */ struct opp_table *opp_table; /* OPP table of the genpd */ unsigned int (*opp_to_performance_state)(struct generic_pm_domain *genpd, struct dev_pm_opp *opp); @@ -178,6 +186,7 @@ struct generic_pm_domain_data { struct pm_domain_data base; struct gpd_timing_data td; struct notifier_block nb; + struct notifier_block *power_nb; int cpu; unsigned int performance_state; void *data; @@ -204,6 +213,8 @@ int pm_genpd_init(struct generic_pm_domain *genpd, struct dev_power_governor *gov, bool is_off); int pm_genpd_remove(struct generic_pm_domain *genpd); int dev_pm_genpd_set_performance_state(struct device *dev, unsigned int state); +int dev_pm_genpd_add_notifier(struct device *dev, struct notifier_block *nb); +int dev_pm_genpd_remove_notifier(struct device *dev); extern struct dev_power_governor simple_qos_governor; extern struct dev_power_governor pm_domain_always_on_gov; @@ -251,6 +262,17 @@ static inline int dev_pm_genpd_set_performance_state(struct device *dev, return -ENOTSUPP; } +static inline int dev_pm_genpd_add_notifier(struct device *dev, + struct notifier_block *nb) +{ + return -ENOTSUPP; +} + +static inline int dev_pm_genpd_remove_notifier(struct device *dev) +{ + return -ENOTSUPP; +} + #define simple_qos_governor (*(struct dev_power_governor *)(NULL)) #define pm_domain_always_on_gov (*(struct dev_power_governor *)(NULL)) #endif -- cgit v1.2.3-58-ga151