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 #define POWER_MODULE_API_VERSION_0_1 HARDWARE_MODULE_API_VERSION(0, 1) 29 #define POWER_MODULE_API_VERSION_0_2 HARDWARE_MODULE_API_VERSION(0, 2) 30 31 /** 32 * The id of this module 33 */ 34 #define POWER_HARDWARE_MODULE_ID "power" 35 36 /* 37 * Power hint identifiers passed to (*powerHint) 38 */ 39 40 typedef enum { 41 POWER_HINT_VSYNC = 0x00000001, 42 POWER_HINT_INTERACTION = 0x00000002, 43 /* DO NOT USE POWER_HINT_VIDEO_ENCODE/_DECODE! They will be removed in 44 * KLP. 45 */ 46 POWER_HINT_VIDEO_ENCODE = 0x00000003, 47 POWER_HINT_VIDEO_DECODE = 0x00000004 48 } power_hint_t; 49 50 /** 51 * Every hardware module must have a data structure named HAL_MODULE_INFO_SYM 52 * and the fields of this data structure must begin with hw_module_t 53 * followed by module specific information. 54 */ 55 typedef struct power_module { 56 struct hw_module_t common; 57 58 /* 59 * (*init)() performs power management setup actions at runtime 60 * startup, such as to set default cpufreq parameters. This is 61 * called only by the Power HAL instance loaded by 62 * PowerManagerService. 63 */ 64 void (*init)(struct power_module *module); 65 66 /* 67 * (*setInteractive)() performs power management actions upon the 68 * system entering interactive state (that is, the system is awake 69 * and ready for interaction, often with UI devices such as 70 * display and touchscreen enabled) or non-interactive state (the 71 * system appears asleep, display usually turned off). The 72 * non-interactive state is usually entered after a period of 73 * inactivity, in order to conserve battery power during 74 * such inactive periods. 75 * 76 * Typical actions are to turn on or off devices and adjust 77 * cpufreq parameters. This function may also call the 78 * appropriate interfaces to allow the kernel to suspend the 79 * system to low-power sleep state when entering non-interactive 80 * state, and to disallow low-power suspend when the system is in 81 * interactive state. When low-power suspend state is allowed, the 82 * kernel may suspend the system whenever no wakelocks are held. 83 * 84 * on is non-zero when the system is transitioning to an 85 * interactive / awake state, and zero when transitioning to a 86 * non-interactive / asleep state. 87 * 88 * This function is called to enter non-interactive state after 89 * turning off the screen (if present), and called to enter 90 * interactive state prior to turning on the screen. 91 */ 92 void (*setInteractive)(struct power_module *module, int on); 93 94 /* 95 * (*powerHint) is called to pass hints on power requirements, which 96 * may result in adjustment of power/performance parameters of the 97 * cpufreq governor and other controls. The possible hints are: 98 * 99 * POWER_HINT_VSYNC 100 * 101 * Foreground app has started or stopped requesting a VSYNC pulse 102 * from SurfaceFlinger. If the app has started requesting VSYNC 103 * then CPU and GPU load is expected soon, and it may be appropriate 104 * to raise speeds of CPU, memory bus, etc. The data parameter is 105 * non-zero to indicate VSYNC pulse is now requested, or zero for 106 * VSYNC pulse no longer requested. 107 * 108 * POWER_HINT_INTERACTION 109 * 110 * User is interacting with the device, for example, touchscreen 111 * events are incoming. CPU and GPU load may be expected soon, 112 * and it may be appropriate to raise speeds of CPU, memory bus, 113 * etc. The data parameter is unused. 114 * 115 * A particular platform may choose to ignore any hint. 116 * 117 * availability: version 0.2 118 * 119 */ 120 void (*powerHint)(struct power_module *module, power_hint_t hint, 121 void *data); 122 } power_module_t; 123 124 125 __END_DECLS 126 127 #endif // ANDROID_INCLUDE_HARDWARE_POWER_H 128