linux/drivers/thermal/thermal_core.h
Javi Merino 6b775e870c thermal: introduce the Power Allocator governor
The power allocator governor is a thermal governor that controls system
and device power allocation to control temperature.  Conceptually, the
implementation divides the sustainable power of a thermal zone among
all the heat sources in that zone.

This governor relies on "power actors", entities that represent heat
sources.  They can report current and maximum power consumption and
can set a given maximum power consumption, usually via a cooling
device.

The governor uses a Proportional Integral Derivative (PID) controller
driven by the temperature of the thermal zone.  The output of the
controller is a power budget that is then allocated to each power
actor that can have bearing on the temperature we are trying to
control.  It decides how much power to give each cooling device based
on the performance they are requesting.  The PID controller ensures
that the total power budget does not exceed the control temperature.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
Signed-off-by: Javi Merino <javi.merino@arm.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2015-05-04 21:27:52 -07:00

127 lines
4.4 KiB
C

/*
* thermal_core.h
*
* Copyright (C) 2012 Intel Corp
* Author: Durgadoss R <durgadoss.r@intel.com>
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*/
#ifndef __THERMAL_CORE_H__
#define __THERMAL_CORE_H__
#include <linux/device.h>
#include <linux/thermal.h>
/* Initial state of a cooling device during binding */
#define THERMAL_NO_TARGET -1UL
/*
* This structure is used to describe the behavior of
* a certain cooling device on a certain trip point
* in a certain thermal zone
*/
struct thermal_instance {
int id;
char name[THERMAL_NAME_LENGTH];
struct thermal_zone_device *tz;
struct thermal_cooling_device *cdev;
int trip;
unsigned long upper; /* Highest cooling state for this trip point */
unsigned long lower; /* Lowest cooling state for this trip point */
unsigned long target; /* expected cooling state */
char attr_name[THERMAL_NAME_LENGTH];
struct device_attribute attr;
char weight_attr_name[THERMAL_NAME_LENGTH];
struct device_attribute weight_attr;
struct list_head tz_node; /* node in tz->thermal_instances */
struct list_head cdev_node; /* node in cdev->thermal_instances */
unsigned int weight; /* The weight of the cooling device */
};
int thermal_register_governor(struct thermal_governor *);
void thermal_unregister_governor(struct thermal_governor *);
#ifdef CONFIG_THERMAL_GOV_STEP_WISE
int thermal_gov_step_wise_register(void);
void thermal_gov_step_wise_unregister(void);
#else
static inline int thermal_gov_step_wise_register(void) { return 0; }
static inline void thermal_gov_step_wise_unregister(void) {}
#endif /* CONFIG_THERMAL_GOV_STEP_WISE */
#ifdef CONFIG_THERMAL_GOV_FAIR_SHARE
int thermal_gov_fair_share_register(void);
void thermal_gov_fair_share_unregister(void);
#else
static inline int thermal_gov_fair_share_register(void) { return 0; }
static inline void thermal_gov_fair_share_unregister(void) {}
#endif /* CONFIG_THERMAL_GOV_FAIR_SHARE */
#ifdef CONFIG_THERMAL_GOV_BANG_BANG
int thermal_gov_bang_bang_register(void);
void thermal_gov_bang_bang_unregister(void);
#else
static inline int thermal_gov_bang_bang_register(void) { return 0; }
static inline void thermal_gov_bang_bang_unregister(void) {}
#endif /* CONFIG_THERMAL_GOV_BANG_BANG */
#ifdef CONFIG_THERMAL_GOV_USER_SPACE
int thermal_gov_user_space_register(void);
void thermal_gov_user_space_unregister(void);
#else
static inline int thermal_gov_user_space_register(void) { return 0; }
static inline void thermal_gov_user_space_unregister(void) {}
#endif /* CONFIG_THERMAL_GOV_USER_SPACE */
#ifdef CONFIG_THERMAL_GOV_POWER_ALLOCATOR
int thermal_gov_power_allocator_register(void);
void thermal_gov_power_allocator_unregister(void);
#else
static inline int thermal_gov_power_allocator_register(void) { return 0; }
static inline void thermal_gov_power_allocator_unregister(void) {}
#endif /* CONFIG_THERMAL_GOV_POWER_ALLOCATOR */
/* device tree support */
#ifdef CONFIG_THERMAL_OF
int of_parse_thermal_zones(void);
void of_thermal_destroy_zones(void);
int of_thermal_get_ntrips(struct thermal_zone_device *);
bool of_thermal_is_trip_valid(struct thermal_zone_device *, int);
const struct thermal_trip *
of_thermal_get_trip_points(struct thermal_zone_device *);
#else
static inline int of_parse_thermal_zones(void) { return 0; }
static inline void of_thermal_destroy_zones(void) { }
static inline int of_thermal_get_ntrips(struct thermal_zone_device *tz)
{
return 0;
}
static inline bool of_thermal_is_trip_valid(struct thermal_zone_device *tz,
int trip)
{
return 0;
}
static inline const struct thermal_trip *
of_thermal_get_trip_points(struct thermal_zone_device *tz)
{
return NULL;
}
#endif
#endif /* __THERMAL_CORE_H__ */