/* SPDX-License-Identifier: GPL-2.0-only */ /* * devfreq: Generic Dynamic Voltage and Frequency Scaling (DVFS) Framework * for Non-CPU Devices. * * Copyright (C) 2011 Samsung Electronics * MyungJoo Ham <[email protected]> */ #ifndef __LINUX_DEVFREQ_H__ #define __LINUX_DEVFREQ_H__ #include <linux/device.h> #include <linux/notifier.h> #include <linux/pm_opp.h> #include <linux/pm_qos.h> /* DEVFREQ governor name */ #define DEVFREQ_GOV_SIMPLE_ONDEMAND … #define DEVFREQ_GOV_PERFORMANCE … #define DEVFREQ_GOV_POWERSAVE … #define DEVFREQ_GOV_USERSPACE … #define DEVFREQ_GOV_PASSIVE … /* DEVFREQ notifier interface */ #define DEVFREQ_TRANSITION_NOTIFIER … /* Transition notifiers of DEVFREQ_TRANSITION_NOTIFIER */ #define DEVFREQ_PRECHANGE … #define DEVFREQ_POSTCHANGE … /* DEVFREQ work timers */ enum devfreq_timer { … }; struct devfreq; struct devfreq_governor; struct devfreq_cpu_data; struct thermal_cooling_device; /** * struct devfreq_dev_status - Data given from devfreq user device to * governors. Represents the performance * statistics. * @total_time: The total time represented by this instance of * devfreq_dev_status * @busy_time: The time that the device was working among the * total_time. * @current_frequency: The operating frequency. * @private_data: An entry not specified by the devfreq framework. * A device and a specific governor may have their * own protocol with private_data. However, because * this is governor-specific, a governor using this * will be only compatible with devices aware of it. */ struct devfreq_dev_status { … }; /* * The resulting frequency should be at most this. (this bound is the * least upper bound; thus, the resulting freq should be lower or same) * If the flag is not set, the resulting frequency should be at most the * bound (greatest lower bound) */ #define DEVFREQ_FLAG_LEAST_UPPER_BOUND … /** * struct devfreq_dev_profile - Devfreq's user device profile * @initial_freq: The operating frequency when devfreq_add_device() is * called. * @polling_ms: The polling interval in ms. 0 disables polling. * @timer: Timer type is either deferrable or delayed timer. * @target: The device should set its operating frequency at * freq or lowest-upper-than-freq value. If freq is * higher than any operable frequency, set maximum. * Before returning, target function should set * freq at the current frequency. * The "flags" parameter's possible values are * explained above with "DEVFREQ_FLAG_*" macros. * @get_dev_status: The device should provide the current performance * status to devfreq. Governors are recommended not to * use this directly. Instead, governors are recommended * to use devfreq_update_stats() along with * devfreq.last_status. * @get_cur_freq: The device should provide the current frequency * at which it is operating. * @exit: An optional callback that is called when devfreq * is removing the devfreq object due to error or * from devfreq_remove_device() call. If the user * has registered devfreq->nb at a notifier-head, * this is the time to unregister it. * @freq_table: Optional list of frequencies to support statistics * and freq_table must be generated in ascending order. * @max_state: The size of freq_table. * * @is_cooling_device: A self-explanatory boolean giving the device a * cooling effect property. */ struct devfreq_dev_profile { … }; /** * struct devfreq_stats - Statistics of devfreq device behavior * @total_trans: Number of devfreq transitions. * @trans_table: Statistics of devfreq transitions. * @time_in_state: Statistics of devfreq states. * @last_update: The last time stats were updated. */ struct devfreq_stats { … }; /** * struct devfreq - Device devfreq structure * @node: list node - contains the devices with devfreq that have been * registered. * @lock: a mutex to protect accessing devfreq. * @dev: device registered by devfreq class. dev.parent is the device * using devfreq. * @profile: device-specific devfreq profile * @governor: method how to choose frequency based on the usage. * @opp_table: Reference to OPP table of dev.parent, if one exists. * @nb: notifier block used to notify devfreq object that it should * reevaluate operable frequencies. Devfreq users may use * devfreq.nb to the corresponding register notifier call chain. * @work: delayed work for load monitoring. * @freq_table: current frequency table used by the devfreq driver. * @max_state: count of entry present in the frequency table. * @previous_freq: previously configured frequency value. * @last_status: devfreq user device info, performance statistics * @data: devfreq driver pass to governors, governor should not change it. * @governor_data: private data for governors, devfreq core doesn't touch it. * @user_min_freq_req: PM QoS minimum frequency request from user (via sysfs) * @user_max_freq_req: PM QoS maximum frequency request from user (via sysfs) * @scaling_min_freq: Limit minimum frequency requested by OPP interface * @scaling_max_freq: Limit maximum frequency requested by OPP interface * @stop_polling: devfreq polling status of a device. * @suspend_freq: frequency of a device set during suspend phase. * @resume_freq: frequency of a device set in resume phase. * @suspend_count: suspend requests counter for a device. * @stats: Statistics of devfreq device behavior * @transition_notifier_list: list head of DEVFREQ_TRANSITION_NOTIFIER notifier * @cdev: Cooling device pointer if the devfreq has cooling property * @nb_min: Notifier block for DEV_PM_QOS_MIN_FREQUENCY * @nb_max: Notifier block for DEV_PM_QOS_MAX_FREQUENCY * * This structure stores the devfreq information for a given device. * * Note that when a governor accesses entries in struct devfreq in its * functions except for the context of callbacks defined in struct * devfreq_governor, the governor should protect its access with the * struct mutex lock in struct devfreq. A governor may use this mutex * to protect its own private data in ``void *data`` as well. */ struct devfreq { … }; struct devfreq_freqs { … }; #if defined(CONFIG_PM_DEVFREQ) struct devfreq *devfreq_add_device(struct device *dev, struct devfreq_dev_profile *profile, const char *governor_name, void *data); int devfreq_remove_device(struct devfreq *devfreq); struct devfreq *devm_devfreq_add_device(struct device *dev, struct devfreq_dev_profile *profile, const char *governor_name, void *data); void devm_devfreq_remove_device(struct device *dev, struct devfreq *devfreq); /* Supposed to be called by PM callbacks */ int devfreq_suspend_device(struct devfreq *devfreq); int devfreq_resume_device(struct devfreq *devfreq); void devfreq_suspend(void); void devfreq_resume(void); /* update_devfreq() - Reevaluate the device and configure frequency */ int update_devfreq(struct devfreq *devfreq); /* Helper functions for devfreq user device driver with OPP. */ struct dev_pm_opp *devfreq_recommended_opp(struct device *dev, unsigned long *freq, u32 flags); int devfreq_register_opp_notifier(struct device *dev, struct devfreq *devfreq); int devfreq_unregister_opp_notifier(struct device *dev, struct devfreq *devfreq); int devm_devfreq_register_opp_notifier(struct device *dev, struct devfreq *devfreq); void devm_devfreq_unregister_opp_notifier(struct device *dev, struct devfreq *devfreq); int devfreq_register_notifier(struct devfreq *devfreq, struct notifier_block *nb, unsigned int list); int devfreq_unregister_notifier(struct devfreq *devfreq, struct notifier_block *nb, unsigned int list); int devm_devfreq_register_notifier(struct device *dev, struct devfreq *devfreq, struct notifier_block *nb, unsigned int list); void devm_devfreq_unregister_notifier(struct device *dev, struct devfreq *devfreq, struct notifier_block *nb, unsigned int list); struct devfreq *devfreq_get_devfreq_by_node(struct device_node *node); struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev, const char *phandle_name, int index); #endif /* CONFIG_PM_DEVFREQ */ /** * struct devfreq_simple_ondemand_data - ``void *data`` fed to struct devfreq * and devfreq_add_device * @upthreshold: If the load is over this value, the frequency jumps. * Specify 0 to use the default. Valid value = 0 to 100. * @downdifferential: If the load is under upthreshold - downdifferential, * the governor may consider slowing the frequency down. * Specify 0 to use the default. Valid value = 0 to 100. * downdifferential < upthreshold must hold. * * If the fed devfreq_simple_ondemand_data pointer is NULL to the governor, * the governor uses the default values. */ struct devfreq_simple_ondemand_data { … }; enum devfreq_parent_dev_type { … }; /** * struct devfreq_passive_data - ``void *data`` fed to struct devfreq * and devfreq_add_device * @parent: the devfreq instance of parent device. * @get_target_freq: Optional callback, Returns desired operating frequency * for the device using passive governor. That is called * when passive governor should decide the next frequency * by using the new frequency of parent devfreq device * using governors except for passive governor. * If the devfreq device has the specific method to decide * the next frequency, should use this callback. * @parent_type: the parent type of the device. * @this: the devfreq instance of own device. * @nb: the notifier block for DEVFREQ_TRANSITION_NOTIFIER or * CPUFREQ_TRANSITION_NOTIFIER list. * @cpu_data_list: the list of cpu frequency data for all cpufreq_policy. * * The devfreq_passive_data have to set the devfreq instance of parent * device with governors except for the passive governor. But, don't need to * initialize the 'this' and 'nb' field because the devfreq core will handle * them. */ struct devfreq_passive_data { … }; #if !defined(CONFIG_PM_DEVFREQ) static inline struct devfreq *devfreq_add_device(struct device *dev, struct devfreq_dev_profile *profile, const char *governor_name, void *data) { return ERR_PTR(-ENOSYS); } static inline int devfreq_remove_device(struct devfreq *devfreq) { return 0; } static inline struct devfreq *devm_devfreq_add_device(struct device *dev, struct devfreq_dev_profile *profile, const char *governor_name, void *data) { return ERR_PTR(-ENOSYS); } static inline void devm_devfreq_remove_device(struct device *dev, struct devfreq *devfreq) { } static inline int devfreq_suspend_device(struct devfreq *devfreq) { return 0; } static inline int devfreq_resume_device(struct devfreq *devfreq) { return 0; } static inline void devfreq_suspend(void) {} static inline void devfreq_resume(void) {} static inline struct dev_pm_opp *devfreq_recommended_opp(struct device *dev, unsigned long *freq, u32 flags) { return ERR_PTR(-EINVAL); } static inline int devfreq_register_opp_notifier(struct device *dev, struct devfreq *devfreq) { return -EINVAL; } static inline int devfreq_unregister_opp_notifier(struct device *dev, struct devfreq *devfreq) { return -EINVAL; } static inline int devm_devfreq_register_opp_notifier(struct device *dev, struct devfreq *devfreq) { return -EINVAL; } static inline void devm_devfreq_unregister_opp_notifier(struct device *dev, struct devfreq *devfreq) { } static inline int devfreq_register_notifier(struct devfreq *devfreq, struct notifier_block *nb, unsigned int list) { return 0; } static inline int devfreq_unregister_notifier(struct devfreq *devfreq, struct notifier_block *nb, unsigned int list) { return 0; } static inline int devm_devfreq_register_notifier(struct device *dev, struct devfreq *devfreq, struct notifier_block *nb, unsigned int list) { return 0; } static inline void devm_devfreq_unregister_notifier(struct device *dev, struct devfreq *devfreq, struct notifier_block *nb, unsigned int list) { } static inline struct devfreq *devfreq_get_devfreq_by_node(struct device_node *node) { return ERR_PTR(-ENODEV); } static inline struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev, const char *phandle_name, int index) { return ERR_PTR(-ENODEV); } static inline int devfreq_update_stats(struct devfreq *df) { return -EINVAL; } #endif /* CONFIG_PM_DEVFREQ */ #endif /* __LINUX_DEVFREQ_H__ */
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