| /* | |
| * devfreq: Generic Dynamic Voltage and Frequency Scaling (DVFS) Framework | |
| * for Non-CPU Devices. | |
| * | |
| * Copyright (C) 2011 Samsung Electronics | |
| * MyungJoo Ham <myungjoo.ham@samsung.com> | |
| * | |
| * This program is free software; you can redistribute it and/or modify | |
| * it under the terms of the GNU General Public License version 2 as | |
| * published by the Free Software Foundation. | |
| */ | |
| #ifndef __LINUX_DEVFREQ_H__ | |
| #define __LINUX_DEVFREQ_H__ | |
| #include <linux/device.h> | |
| #include <linux/notifier.h> | |
| #include <linux/opp.h> | |
| #define DEVFREQ_NAME_LEN 16 | |
| struct devfreq; | |
| /** | |
| * 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. | |
| * @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, which is used by governors. | |
| * @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. | |
| */ | |
| struct devfreq_dev_profile { | |
| unsigned long initial_freq; | |
| unsigned int polling_ms; | |
| int (*target)(struct device *dev, unsigned long *freq, u32 flags); | |
| int (*get_dev_status)(struct device *dev, | |
| struct devfreq_dev_status *stat); | |
| void (*exit)(struct device *dev); | |
| }; | |
| /** | |
| * struct devfreq_governor - Devfreq policy governor | |
| * @name Governor's name | |
| * @get_target_freq Returns desired operating frequency for the device. | |
| * Basically, get_target_freq will run | |
| * devfreq_dev_profile.get_dev_status() to get the | |
| * status of the device (load = busy_time / total_time). | |
| * If no_central_polling is set, this callback is called | |
| * only with update_devfreq() notified by OPP. | |
| * @init Called when the devfreq is being attached to a device | |
| * @exit Called when the devfreq is being removed from a | |
| * device. Governor should stop any internal routines | |
| * before return because related data may be | |
| * freed after exit(). | |
| * @no_central_polling Do not use devfreq's central polling mechanism. | |
| * When this is set, devfreq will not call | |
| * get_target_freq with devfreq_monitor(). However, | |
| * devfreq will call get_target_freq with | |
| * devfreq_update() notified by OPP framework. | |
| * | |
| * Note that the callbacks are called with devfreq->lock locked by devfreq. | |
| */ | |
| struct devfreq_governor { | |
| const char name[DEVFREQ_NAME_LEN]; | |
| int (*get_target_freq)(struct devfreq *this, unsigned long *freq); | |
| int (*init)(struct devfreq *this); | |
| void (*exit)(struct devfreq *this); | |
| const bool no_central_polling; | |
| }; | |
| /** | |
| * 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. | |
| * @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. | |
| * @polling_jiffies interval in jiffies. | |
| * @previous_freq previously configured frequency value. | |
| * @next_polling the number of remaining jiffies to poll with | |
| * "devfreq_monitor" executions to reevaluate | |
| * frequency/voltage of the device. Set by | |
| * profile's polling_ms interval. | |
| * @data Private data of the governor. The devfreq framework does not | |
| * touch this. | |
| * @being_removed a flag to mark that this object is being removed in | |
| * order to prevent trying to remove the object multiple times. | |
| * @min_freq Limit minimum frequency requested by user (0: none) | |
| * @max_freq Limit maximum frequency requested by user (0: none) | |
| * | |
| * This structure stores the devfreq information for a give 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 notifier_block nb; | |
| unsigned long polling_jiffies; | |
| unsigned long previous_freq; | |
| unsigned int next_polling; | |
| void *data; /* private data for governors */ | |
| bool being_removed; | |
| unsigned long min_freq; | |
| unsigned long max_freq; | |
| }; | |
| #if defined(CONFIG_PM_DEVFREQ) | |
| extern struct devfreq *devfreq_add_device(struct device *dev, | |
| struct devfreq_dev_profile *profile, | |
| const struct devfreq_governor *governor, | |
| void *data); | |
| extern int devfreq_remove_device(struct devfreq *devfreq); | |
| /* Helper functions for devfreq user device driver with OPP. */ | |
| extern struct opp *devfreq_recommended_opp(struct device *dev, | |
| unsigned long *freq, u32 flags); | |
| extern int devfreq_register_opp_notifier(struct device *dev, | |
| struct devfreq *devfreq); | |
| extern int devfreq_unregister_opp_notifier(struct device *dev, | |
| struct devfreq *devfreq); | |
| #ifdef CONFIG_DEVFREQ_GOV_POWERSAVE | |
| extern const struct devfreq_governor devfreq_powersave; | |
| #endif | |
| #ifdef CONFIG_DEVFREQ_GOV_PERFORMANCE | |
| extern const struct devfreq_governor devfreq_performance; | |
| #endif | |
| #ifdef CONFIG_DEVFREQ_GOV_USERSPACE | |
| extern const struct devfreq_governor devfreq_userspace; | |
| #endif | |
| #ifdef CONFIG_DEVFREQ_GOV_SIMPLE_ONDEMAND | |
| extern const struct devfreq_governor devfreq_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 | |
| #else /* !CONFIG_PM_DEVFREQ */ | |
| static struct devfreq *devfreq_add_device(struct device *dev, | |
| struct devfreq_dev_profile *profile, | |
| struct devfreq_governor *governor, | |
| void *data) | |
| { | |
| return NULL; | |
| } | |
| static int devfreq_remove_device(struct devfreq *devfreq) | |
| { | |
| return 0; | |
| } | |
| static struct opp *devfreq_recommended_opp(struct device *dev, | |
| unsigned long *freq, u32 flags) | |
| { | |
| return -EINVAL; | |
| } | |
| static int devfreq_register_opp_notifier(struct device *dev, | |
| struct devfreq *devfreq) | |
| { | |
| return -EINVAL; | |
| } | |
| static int devfreq_unregister_opp_notifier(struct device *dev, | |
| struct devfreq *devfreq) | |
| { | |
| return -EINVAL; | |
| } | |
| #define devfreq_powersave NULL | |
| #define devfreq_performance NULL | |
| #define devfreq_userspace NULL | |
| #define devfreq_simple_ondemand NULL | |
| #endif /* CONFIG_PM_DEVFREQ */ | |
| #endif /* __LINUX_DEVFREQ_H__ */ |