cbc9ef0287
On some systems there are CPU cores located in the same power domains as I/O devices. Then, power can only be removed from the domain if all I/O devices in it are not in use and the CPU core is idle. Add preliminary support for that to the generic PM domains framework. First, the platform is expected to provide a cpuidle driver with one extra state designated for use with the generic PM domains code. This state should be initially disabled and its exit_latency value should be set to whatever time is needed to bring up the CPU core itself after restoring power to it, not including the domain's power on latency. Its .enter() callback should point to a procedure that will remove power from the domain containing the CPU core at the end of the CPU power transition. The remaining characteristics of the extra cpuidle state, referred to as the "domain" cpuidle state below, (e.g. power usage, target residency) should be populated in accordance with the properties of the hardware. Next, the platform should execute genpd_attach_cpuidle() on the PM domain containing the CPU core. That will cause the generic PM domains framework to treat that domain in a special way such that: * When all devices in the domain have been suspended and it is about to be turned off, the states of the devices will be saved, but power will not be removed from the domain. Instead, the "domain" cpuidle state will be enabled so that power can be removed from the domain when the CPU core is idle and the state has been chosen as the target by the cpuidle governor. * When the first I/O device in the domain is resumed and __pm_genpd_poweron(() is called for the first time after power has been removed from the domain, the "domain" cpuidle state will be disabled to avoid subsequent surprise power removals via cpuidle. The effective exit_latency value of the "domain" cpuidle state depends on the time needed to bring up the CPU core itself after restoring power to it as well as on the power on latency of the domain containing the CPU core. Thus the "domain" cpuidle state's exit_latency has to be recomputed every time the domain's power on latency is updated, which may happen every time power is restored to the domain, if the measured power on latency is greater than the latency stored in the corresponding generic_pm_domain structure. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Reviewed-by: Kevin Hilman <khilman@ti.com>
260 lines
7.9 KiB
C
260 lines
7.9 KiB
C
/*
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* pm_domain.h - Definitions and headers related to device power domains.
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*
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* Copyright (C) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Renesas Electronics Corp.
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*
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* This file is released under the GPLv2.
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*/
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#ifndef _LINUX_PM_DOMAIN_H
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#define _LINUX_PM_DOMAIN_H
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#include <linux/device.h>
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#include <linux/mutex.h>
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#include <linux/pm.h>
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#include <linux/err.h>
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#include <linux/of.h>
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#include <linux/notifier.h>
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#include <linux/cpuidle.h>
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enum gpd_status {
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GPD_STATE_ACTIVE = 0, /* PM domain is active */
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GPD_STATE_WAIT_MASTER, /* PM domain's master is being waited for */
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GPD_STATE_BUSY, /* Something is happening to the PM domain */
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GPD_STATE_REPEAT, /* Power off in progress, to be repeated */
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GPD_STATE_POWER_OFF, /* PM domain is off */
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};
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struct dev_power_governor {
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bool (*power_down_ok)(struct dev_pm_domain *domain);
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bool (*stop_ok)(struct device *dev);
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};
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struct gpd_dev_ops {
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int (*start)(struct device *dev);
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int (*stop)(struct device *dev);
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int (*save_state)(struct device *dev);
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int (*restore_state)(struct device *dev);
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int (*suspend)(struct device *dev);
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int (*suspend_late)(struct device *dev);
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int (*resume_early)(struct device *dev);
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int (*resume)(struct device *dev);
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int (*freeze)(struct device *dev);
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int (*freeze_late)(struct device *dev);
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int (*thaw_early)(struct device *dev);
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int (*thaw)(struct device *dev);
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bool (*active_wakeup)(struct device *dev);
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};
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struct gpd_cpu_data {
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unsigned int saved_exit_latency;
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struct cpuidle_state *idle_state;
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};
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struct generic_pm_domain {
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struct dev_pm_domain domain; /* PM domain operations */
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struct list_head gpd_list_node; /* Node in the global PM domains list */
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struct list_head master_links; /* Links with PM domain as a master */
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struct list_head slave_links; /* Links with PM domain as a slave */
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struct list_head dev_list; /* List of devices */
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struct mutex lock;
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struct dev_power_governor *gov;
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struct work_struct power_off_work;
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char *name;
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unsigned int in_progress; /* Number of devices being suspended now */
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atomic_t sd_count; /* Number of subdomains with power "on" */
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enum gpd_status status; /* Current state of the domain */
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wait_queue_head_t status_wait_queue;
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struct task_struct *poweroff_task; /* Powering off task */
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unsigned int resume_count; /* Number of devices being resumed */
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unsigned int device_count; /* Number of devices */
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unsigned int suspended_count; /* System suspend device counter */
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unsigned int prepared_count; /* Suspend counter of prepared devices */
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bool suspend_power_off; /* Power status before system suspend */
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bool dev_irq_safe; /* Device callbacks are IRQ-safe */
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int (*power_off)(struct generic_pm_domain *domain);
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s64 power_off_latency_ns;
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int (*power_on)(struct generic_pm_domain *domain);
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s64 power_on_latency_ns;
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struct gpd_dev_ops dev_ops;
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s64 max_off_time_ns; /* Maximum allowed "suspended" time. */
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bool max_off_time_changed;
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bool cached_power_down_ok;
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struct device_node *of_node; /* Node in device tree */
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struct gpd_cpu_data *cpu_data;
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};
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static inline struct generic_pm_domain *pd_to_genpd(struct dev_pm_domain *pd)
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{
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return container_of(pd, struct generic_pm_domain, domain);
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}
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struct gpd_link {
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struct generic_pm_domain *master;
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struct list_head master_node;
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struct generic_pm_domain *slave;
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struct list_head slave_node;
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};
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struct gpd_timing_data {
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s64 stop_latency_ns;
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s64 start_latency_ns;
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s64 save_state_latency_ns;
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s64 restore_state_latency_ns;
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s64 effective_constraint_ns;
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bool constraint_changed;
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bool cached_stop_ok;
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};
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struct generic_pm_domain_data {
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struct pm_domain_data base;
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struct gpd_dev_ops ops;
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struct gpd_timing_data td;
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struct notifier_block nb;
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struct mutex lock;
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bool need_restore;
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bool always_on;
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};
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#ifdef CONFIG_PM_GENERIC_DOMAINS
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static inline struct generic_pm_domain_data *to_gpd_data(struct pm_domain_data *pdd)
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{
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return container_of(pdd, struct generic_pm_domain_data, base);
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}
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static inline struct generic_pm_domain_data *dev_gpd_data(struct device *dev)
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{
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return to_gpd_data(dev->power.subsys_data->domain_data);
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}
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extern struct dev_power_governor simple_qos_governor;
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extern struct generic_pm_domain *dev_to_genpd(struct device *dev);
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extern int __pm_genpd_add_device(struct generic_pm_domain *genpd,
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struct device *dev,
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struct gpd_timing_data *td);
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extern int __pm_genpd_of_add_device(struct device_node *genpd_node,
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struct device *dev,
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struct gpd_timing_data *td);
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static inline int pm_genpd_add_device(struct generic_pm_domain *genpd,
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struct device *dev)
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{
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return __pm_genpd_add_device(genpd, dev, NULL);
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}
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static inline int pm_genpd_of_add_device(struct device_node *genpd_node,
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struct device *dev)
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{
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return __pm_genpd_of_add_device(genpd_node, dev, NULL);
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}
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extern int pm_genpd_remove_device(struct generic_pm_domain *genpd,
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struct device *dev);
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extern void pm_genpd_dev_always_on(struct device *dev, bool val);
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extern void pm_genpd_dev_need_restore(struct device *dev, bool val);
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extern int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
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struct generic_pm_domain *new_subdomain);
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extern int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd,
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struct generic_pm_domain *target);
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extern int pm_genpd_add_callbacks(struct device *dev,
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struct gpd_dev_ops *ops,
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struct gpd_timing_data *td);
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extern int __pm_genpd_remove_callbacks(struct device *dev, bool clear_td);
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extern int genpd_attach_cpuidle(struct generic_pm_domain *genpd, int state);
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extern int genpd_detach_cpuidle(struct generic_pm_domain *genpd);
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extern void pm_genpd_init(struct generic_pm_domain *genpd,
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struct dev_power_governor *gov, bool is_off);
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extern int pm_genpd_poweron(struct generic_pm_domain *genpd);
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extern bool default_stop_ok(struct device *dev);
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extern struct dev_power_governor pm_domain_always_on_gov;
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#else
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static inline struct generic_pm_domain_data *dev_gpd_data(struct device *dev)
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{
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return ERR_PTR(-ENOSYS);
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}
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static inline struct generic_pm_domain *dev_to_genpd(struct device *dev)
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{
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return ERR_PTR(-ENOSYS);
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}
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static inline int __pm_genpd_add_device(struct generic_pm_domain *genpd,
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struct device *dev,
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struct gpd_timing_data *td)
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{
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return -ENOSYS;
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}
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static inline int pm_genpd_add_device(struct generic_pm_domain *genpd,
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struct device *dev)
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{
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return -ENOSYS;
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}
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static inline int pm_genpd_remove_device(struct generic_pm_domain *genpd,
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struct device *dev)
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{
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return -ENOSYS;
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}
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static inline void pm_genpd_dev_always_on(struct device *dev, bool val) {}
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static inline void pm_genpd_dev_need_restore(struct device *dev, bool val) {}
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static inline int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
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struct generic_pm_domain *new_sd)
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{
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return -ENOSYS;
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}
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static inline int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd,
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struct generic_pm_domain *target)
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{
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return -ENOSYS;
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}
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static inline int pm_genpd_add_callbacks(struct device *dev,
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struct gpd_dev_ops *ops,
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struct gpd_timing_data *td)
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{
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return -ENOSYS;
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}
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static inline int __pm_genpd_remove_callbacks(struct device *dev, bool clear_td)
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{
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return -ENOSYS;
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}
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static inline int genpd_attach_cpuidle(struct generic_pm_domain *genpd, int st)
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{
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return -ENOSYS;
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}
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static inline int genpd_detach_cpuidle(struct generic_pm_domain *genpd)
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{
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return -ENOSYS;
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}
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static inline void pm_genpd_init(struct generic_pm_domain *genpd,
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struct dev_power_governor *gov, bool is_off)
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{
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}
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static inline int pm_genpd_poweron(struct generic_pm_domain *genpd)
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{
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return -ENOSYS;
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}
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static inline bool default_stop_ok(struct device *dev)
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{
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return false;
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}
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#define simple_qos_governor NULL
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#define pm_domain_always_on_gov NULL
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#endif
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static inline int pm_genpd_remove_callbacks(struct device *dev)
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{
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return __pm_genpd_remove_callbacks(dev, true);
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}
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#ifdef CONFIG_PM_GENERIC_DOMAINS_RUNTIME
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extern void genpd_queue_power_off_work(struct generic_pm_domain *genpd);
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extern void pm_genpd_poweroff_unused(void);
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#else
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static inline void genpd_queue_power_off_work(struct generic_pm_domain *gpd) {}
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static inline void pm_genpd_poweroff_unused(void) {}
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#endif
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#endif /* _LINUX_PM_DOMAIN_H */
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