power.h revision c82792c0a4135c1a5de4e4f0ca47318fa5dd7e14
1/* 2 * Copyright (C) 2012 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17#ifndef ANDROID_INCLUDE_HARDWARE_POWER_H 18#define ANDROID_INCLUDE_HARDWARE_POWER_H 19 20#include <stdint.h> 21#include <sys/cdefs.h> 22#include <sys/types.h> 23 24#include <hardware/hardware.h> 25 26__BEGIN_DECLS 27 28/** 29 * The id of this module 30 */ 31#define POWER_HARDWARE_MODULE_ID "power" 32 33/** 34 * Every hardware module must have a data structure named HAL_MODULE_INFO_SYM 35 * and the fields of this data structure must begin with hw_module_t 36 * followed by module specific information. 37 */ 38typedef struct power_module { 39 struct hw_module_t common; 40 41 /* 42 * (*init)() performs power management setup actions at runtime 43 * startup, such as to set default cpufreq parameters. 44 */ 45 void (*init)(struct power_module *module); 46 47 /* 48 * (*setInteractive)() performs power management actions upon the 49 * system entering interactive state (that is, the system is awake 50 * and ready for interaction, often with UI devices such as 51 * display and touchscreen enabled) or non-interactive state (the 52 * system appears asleep, display usually turned off). The 53 * non-interactive state is usually entered after a period of 54 * inactivity, in order to conserve battery power during 55 * such inactive periods. 56 * 57 * Typical actions are to turn on or off devices and adjust 58 * cpufreq parameters. This function may also call the 59 * appropriate interfaces to allow the kernel to suspend the 60 * system to low-power sleep state when entering non-interactive 61 * state, and to disallow low-power suspend when the system is in 62 * interactive state. When low-power suspend state is allowed, the 63 * kernel may suspend the system whenever no wakelocks are held. 64 * 65 * on is non-zero when the system is transitioning to an 66 * interactive / awake state, and zero when transitioning to a 67 * non-interactive / asleep state. 68 * 69 * This function is called to enter non-interactive state after 70 * turning off the screen (if present), and called to enter 71 * interactive state prior to turning on the screen. 72 */ 73 void (*setInteractive)(struct power_module *module, int on); 74} power_module_t; 75 76 77__END_DECLS 78 79#endif // ANDROID_INCLUDE_HARDWARE_POWER_H 80