From fc5cbf0c94b6f7fd62fdddff892207290510945d Mon Sep 17 00:00:00 2001 From: Axel Haslam Date: Mon, 15 Feb 2016 11:10:51 +0100 Subject: PM / Domains: Support for multiple states Some hardware (eg. OMAP), has the ability to enter different low power modes for a given power domain. This allows for more fine grained control over the power state of the platform. As a typical example, some registers of the hardware may be implemented with retention flip-flops and be able to retain their state at lower voltages allowing for faster on/off latencies and an increased window of opportunity to enter an intermediate low power state other than "off" When trying to set a power domain to off, the genpd governor will choose the deepest state that will respect the qos constraints of all the devices and sub-domains on the power domain. The state chosen by the governor is saved in the "state_idx" field of the generic_pm_domain structure and shall be used by the power_off and power_on callbacks to perform the necessary actions to set the power domain into (and out of) the state indicated by state_idx. States must be declared in ascending order from shallowest to deepest, deepest meaning the state which takes longer to enter and exit. For platforms that don't declare any states, a single a single "off" state is used. Once all platforms are converted to use the state array, the legacy on/off latencies will be removed. [ Lina: Modified genpd state initialization and remove use of save_state_latency_ns in genpd timing data ] Suggested-by: Kevin Hilman Signed-off-by: Lina Iyer Signed-off-by: Axel Haslam Acked-by: Ulf Hansson Signed-off-by: Rafael J. Wysocki --- include/linux/pm_domain.h | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'include/linux/pm_domain.h') diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h index db21d3995f7e..1726c4ac6529 100644 --- a/include/linux/pm_domain.h +++ b/include/linux/pm_domain.h @@ -19,6 +19,8 @@ /* Defines used for the flags field in the struct generic_pm_domain */ #define GENPD_FLAG_PM_CLK (1U << 0) /* PM domain uses PM clk */ +#define GENPD_MAX_NUM_STATES 8 /* Number of possible low power states */ + enum gpd_status { GPD_STATE_ACTIVE = 0, /* PM domain is active */ GPD_STATE_POWER_OFF, /* PM domain is off */ @@ -37,6 +39,11 @@ struct gpd_dev_ops { bool (*active_wakeup)(struct device *dev); }; +struct genpd_power_state { + s64 power_off_latency_ns; + s64 power_on_latency_ns; +}; + struct generic_pm_domain { struct dev_pm_domain domain; /* PM domain operations */ struct list_head gpd_list_node; /* Node in the global PM domains list */ @@ -66,6 +73,10 @@ struct generic_pm_domain { void (*detach_dev)(struct generic_pm_domain *domain, struct device *dev); unsigned int flags; /* Bit field of configs for genpd */ + struct genpd_power_state states[GENPD_MAX_NUM_STATES]; + unsigned int state_count; /* number of states */ + unsigned int state_idx; /* state that genpd will go to when off */ + }; static inline struct generic_pm_domain *pd_to_genpd(struct dev_pm_domain *pd) -- cgit