| /* 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 <myungjoo.ham@samsung.com> |
| */ |
| |
| #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 "simple_ondemand" |
| #define DEVFREQ_GOV_PERFORMANCE "performance" |
| #define DEVFREQ_GOV_POWERSAVE "powersave" |
| #define DEVFREQ_GOV_USERSPACE "userspace" |
| #define DEVFREQ_GOV_PASSIVE "passive" |
| |
| /* DEVFREQ notifier interface */ |
| #define DEVFREQ_TRANSITION_NOTIFIER (0) |
| |
| /* Transition notifiers of DEVFREQ_TRANSITION_NOTIFIER */ |
| #define DEVFREQ_PRECHANGE (0) |
| #define DEVFREQ_POSTCHANGE (1) |
| |
| /* DEVFREQ work timers */ |
| enum devfreq_timer { |
| DEVFREQ_TIMER_DEFERRABLE = 0, |
| DEVFREQ_TIMER_DELAYED, |
| DEVFREQ_TIMER_NUM, |
| }; |
| |
| struct devfreq; |
| struct devfreq_governor; |
| 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 { |
| /* both since the last measure */ |
| unsigned long total_time; |
| unsigned long busy_time; |
| unsigned long current_frequency; |
| void *private_data; |
| }; |
| |
| /* |
| * 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 0x1 |
| |
| /** |
| * 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 { |
| unsigned long initial_freq; |
| unsigned int polling_ms; |
| enum devfreq_timer timer; |
| bool is_cooling_device; |
| |
| int (*target)(struct device *dev, unsigned long *freq, u32 flags); |
| int (*get_dev_status)(struct device *dev, |
| struct devfreq_dev_status *stat); |
| int (*get_cur_freq)(struct device *dev, unsigned long *freq); |
| void (*exit)(struct device *dev); |
| |
| unsigned long *freq_table; |
| unsigned int max_state; |
| }; |
| |
| /** |
| * 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 { |
| unsigned int total_trans; |
| unsigned int *trans_table; |
| u64 *time_in_state; |
| u64 last_update; |
| }; |
| |
| /** |
| * 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. |
| * @previous_freq: previously configured frequency value. |
| * @last_status: devfreq user device info, performance statistics |
| * @data: Private data of the governor. The devfreq framework does not |
| * touch this. |
| * @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 list_head node; |
| |
| struct mutex lock; |
| struct device dev; |
| struct devfreq_dev_profile *profile; |
| const struct devfreq_governor *governor; |
| struct opp_table *opp_table; |
| struct notifier_block nb; |
| struct delayed_work work; |
| |
| unsigned long previous_freq; |
| struct devfreq_dev_status last_status; |
| |
| void *data; /* private data for governors */ |
| |
| struct dev_pm_qos_request user_min_freq_req; |
| struct dev_pm_qos_request user_max_freq_req; |
| unsigned long scaling_min_freq; |
| unsigned long scaling_max_freq; |
| bool stop_polling; |
| |
| unsigned long suspend_freq; |
| unsigned long resume_freq; |
| atomic_t suspend_count; |
| |
| /* information for device frequency transitions */ |
| struct devfreq_stats stats; |
| |
| struct srcu_notifier_head transition_notifier_list; |
| |
| /* Pointer to the cooling device if used for thermal mitigation */ |
| struct thermal_cooling_device *cdev; |
| |
| struct notifier_block nb_min; |
| struct notifier_block nb_max; |
| }; |
| |
| struct devfreq_freqs { |
| unsigned long old; |
| unsigned long new; |
| }; |
| |
| #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); |
| |
| #if IS_ENABLED(CONFIG_DEVFREQ_GOV_SIMPLE_ONDEMAND) |
| /** |
| * 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 { |
| unsigned int upthreshold; |
| unsigned int downdifferential; |
| }; |
| #endif |
| |
| #if IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE) |
| /** |
| * 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. |
| * @this: the devfreq instance of own device. |
| * @nb: the notifier block for DEVFREQ_TRANSITION_NOTIFIER list |
| * |
| * 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 { |
| /* Should set the devfreq instance of parent device */ |
| struct devfreq *parent; |
| |
| /* Optional callback to decide the next frequency of passvice device */ |
| int (*get_target_freq)(struct devfreq *this, unsigned long *freq); |
| |
| /* For passive governor's internal use. Don't need to set them */ |
| struct devfreq *this; |
| struct notifier_block nb; |
| }; |
| #endif |
| |
| #else /* !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__ */ |