thermal: Added Bang-bang thermal governor (e4dbf98f) · Commits · 戴 / test

drivers/thermal/Kconfig

+10 −0

Original line number	Diff line number	Diff line
		@@ -84,6 +84,16 @@ config THERMAL_GOV_STEP_WISE
		Enable this to manage platform thermals using a simple linear
		governor.

		config THERMAL_GOV_BANG_BANG
		bool "Bang Bang thermal governor"
		default n
		help
		Enable this to manage platform thermals using bang bang governor.

		Say 'Y' here if you want to use two point temperature regulation
		used for fans without throttling. Some fan drivers depend on this
		governor to be enabled (e.g. acerhdf).

		config THERMAL_GOV_USER_SPACE
		bool "User_space thermal governor"
		help

drivers/thermal/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -11,6 +11,7 @@ thermal_sys-$(CONFIG_THERMAL_OF) += of-thermal.o

		# governors
		thermal_sys-$(CONFIG_THERMAL_GOV_FAIR_SHARE) += fair_share.o
		thermal_sys-$(CONFIG_THERMAL_GOV_BANG_BANG) += gov_bang_bang.o
		thermal_sys-$(CONFIG_THERMAL_GOV_STEP_WISE) += step_wise.o
		thermal_sys-$(CONFIG_THERMAL_GOV_USER_SPACE) += user_space.o

drivers/thermal/gov_bang_bang.c

0 → 100644

+131 −0

Original line number	Diff line number	Diff line
		/*
		* gov_bang_bang.c - A simple thermal throttling governor using hysteresis
		*
		* Copyright (C) 2014 Peter Feuerer <peter@piie.net>
		*
		* Based on step_wise.c with following Copyrights:
		* Copyright (C) 2012 Intel Corp
		* Copyright (C) 2012 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.
		*
		* 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.
		*
		*/

		#include <linux/thermal.h>

		#include "thermal_core.h"

		static void thermal_zone_trip_update(struct thermal_zone_device *tz, int trip)
		{
		long trip_temp;
		unsigned long trip_hyst;
		struct thermal_instance *instance;

		tz->ops->get_trip_temp(tz, trip, &trip_temp);
		tz->ops->get_trip_hyst(tz, trip, &trip_hyst);

		dev_dbg(&tz->device, "Trip%d[temp=%ld]:temp=%d:hyst=%ld\n",
		trip, trip_temp, tz->temperature,
		trip_hyst);

		mutex_lock(&tz->lock);

		list_for_each_entry(instance, &tz->thermal_instances, tz_node) {
		if (instance->trip != trip)
		continue;

		/* in case fan is in initial state, switch the fan off */
		if (instance->target == THERMAL_NO_TARGET)
		instance->target = 0;

		/* in case fan is neither on nor off set the fan to active */
		if (instance->target != 0 && instance->target != 1) {
		pr_warn("Thermal instance %s controlled by bang-bang has unexpected state: %ld\n",
		instance->name, instance->target);
		instance->target = 1;
		}

		/*
		* enable fan when temperature exceeds trip_temp and disable
		* the fan in case it falls below trip_temp minus hysteresis
		*/
		if (instance->target == 0 && tz->temperature >= trip_temp)
		instance->target = 1;
		else if (instance->target == 1 &&
		tz->temperature < trip_temp - trip_hyst)
		instance->target = 0;

		dev_dbg(&instance->cdev->device, "target=%d\n",
		(int)instance->target);

		instance->cdev->updated = false; /* cdev needs update */
		}

		mutex_unlock(&tz->lock);
		}

		/**
		* bang_bang_control - controls devices associated with the given zone
		* @tz - thermal_zone_device
		* @trip - the trip point
		*
		* Regulation Logic: a two point regulation, deliver cooling state depending
		* on the previous state shown in this diagram:
		*
		* Fan: OFF ON
		*
		* \|
		* \|
		* trip_temp: +---->+
		* \| \| ^
		* \| \| \|
		* \| \| Temperature
		* (trip_temp - hyst): +<----+
		* \|
		* \|
		* \|
		*
		* * If the fan is not running and temperature exceeds trip_temp, the fan
		* gets turned on.
		* * In case the fan is running, temperature must fall below
		* (trip_temp - hyst) so that the fan gets turned off again.
		*
		*/
		static int bang_bang_control(struct thermal_zone_device *tz, int trip)
		{
		struct thermal_instance *instance;

		thermal_zone_trip_update(tz, trip);

		mutex_lock(&tz->lock);

		list_for_each_entry(instance, &tz->thermal_instances, tz_node)
		thermal_cdev_update(instance->cdev);

		mutex_unlock(&tz->lock);

		return 0;
		}

		static struct thermal_governor thermal_gov_bang_bang = {
		.name = "bang_bang",
		.throttle = bang_bang_control,
		};

		int thermal_gov_bang_bang_register(void)
		{
		return thermal_register_governor(&thermal_gov_bang_bang);
		}

		void thermal_gov_bang_bang_unregister(void)
		{
		thermal_unregister_governor(&thermal_gov_bang_bang);
		}

drivers/thermal/thermal_core.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -1790,6 +1790,10 @@ static int __init thermal_register_governors(void)
		if (result)
		return result;

		result = thermal_gov_bang_bang_register();
		if (result)
		return result;

		return thermal_gov_user_space_register();
		}

		@@ -1797,6 +1801,7 @@ static void thermal_unregister_governors(void)
		{
		thermal_gov_step_wise_unregister();
		thermal_gov_fair_share_unregister();
		thermal_gov_bang_bang_unregister();
		thermal_gov_user_space_unregister();
		}

drivers/thermal/thermal_core.h

+8 −0

Original line number	Diff line number	Diff line
		@@ -69,6 +69,14 @@ 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);

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