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Diffstat (limited to 'include/linux/devfreq.h')
| -rw-r--r-- | include/linux/devfreq.h | 432 |
1 files changed, 432 insertions, 0 deletions
diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h new file mode 100644 index 000000000..fc4c7ad49 --- /dev/null +++ b/include/linux/devfreq.h @@ -0,0 +1,432 @@ +/* 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> + +#define DEVFREQ_NAME_LEN 16 + +/* 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 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. + */ +struct devfreq_dev_profile { + unsigned long initial_freq; + unsigned int polling_ms; + enum devfreq_timer timer; + + 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. + * @governor_name: devfreq governor name for use with this devfreq + * @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: 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 + * @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; + char governor_name[DEVFREQ_NAME_LEN]; + struct notifier_block nb; + struct delayed_work work; + + unsigned long previous_freq; + struct devfreq_dev_status last_status; + + void *data; + void *governor_data; + + 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; + + 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__ */ |