power.h
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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 #define POWER_MODULE_API_VERSION_0_3 HARDWARE_MODULE_API_VERSION(0, 3)
31 
32 /**
33  * The id of this module
34  */
35 #define POWER_HARDWARE_MODULE_ID "power"
36 
37 /*
38  * Power hint identifiers passed to (*powerHint)
39  */
40 
41 typedef enum {
42  POWER_HINT_VSYNC = 0x00000001,
43  POWER_HINT_INTERACTION = 0x00000002,
44  /* DO NOT USE POWER_HINT_VIDEO_ENCODE/_DECODE! They will be removed in
45  * KLP.
46  */
49  POWER_HINT_LOW_POWER = 0x00000005
50 } power_hint_t;
51 
52 typedef enum {
54 } feature_t;
55 
56 /**
57  * Every hardware module must have a data structure named HAL_MODULE_INFO_SYM
58  * and the fields of this data structure must begin with hw_module_t
59  * followed by module specific information.
60  */
61 typedef struct power_module {
63 
64  /*
65  * (*init)() performs power management setup actions at runtime
66  * startup, such as to set default cpufreq parameters. This is
67  * called only by the Power HAL instance loaded by
68  * PowerManagerService.
69  */
70  void (*init)(struct power_module *module);
71 
72  /*
73  * (*setInteractive)() performs power management actions upon the
74  * system entering interactive state (that is, the system is awake
75  * and ready for interaction, often with UI devices such as
76  * display and touchscreen enabled) or non-interactive state (the
77  * system appears asleep, display usually turned off). The
78  * non-interactive state is usually entered after a period of
79  * inactivity, in order to conserve battery power during
80  * such inactive periods.
81  *
82  * Typical actions are to turn on or off devices and adjust
83  * cpufreq parameters. This function may also call the
84  * appropriate interfaces to allow the kernel to suspend the
85  * system to low-power sleep state when entering non-interactive
86  * state, and to disallow low-power suspend when the system is in
87  * interactive state. When low-power suspend state is allowed, the
88  * kernel may suspend the system whenever no wakelocks are held.
89  *
90  * on is non-zero when the system is transitioning to an
91  * interactive / awake state, and zero when transitioning to a
92  * non-interactive / asleep state.
93  *
94  * This function is called to enter non-interactive state after
95  * turning off the screen (if present), and called to enter
96  * interactive state prior to turning on the screen.
97  */
98  void (*setInteractive)(struct power_module *module, int on);
99 
100  /*
101  * (*powerHint) is called to pass hints on power requirements, which
102  * may result in adjustment of power/performance parameters of the
103  * cpufreq governor and other controls. The possible hints are:
104  *
105  * POWER_HINT_VSYNC
106  *
107  * Foreground app has started or stopped requesting a VSYNC pulse
108  * from SurfaceFlinger. If the app has started requesting VSYNC
109  * then CPU and GPU load is expected soon, and it may be appropriate
110  * to raise speeds of CPU, memory bus, etc. The data parameter is
111  * non-zero to indicate VSYNC pulse is now requested, or zero for
112  * VSYNC pulse no longer requested.
113  *
114  * POWER_HINT_INTERACTION
115  *
116  * User is interacting with the device, for example, touchscreen
117  * events are incoming. CPU and GPU load may be expected soon,
118  * and it may be appropriate to raise speeds of CPU, memory bus,
119  * etc. The data parameter is unused.
120  *
121  * POWER_HINT_LOW_POWER
122  *
123  * Low power mode is activated or deactivated. Low power mode
124  * is intended to save battery at the cost of performance. The data
125  * parameter is non-zero when low power mode is activated, and zero
126  * when deactivated.
127  *
128  * A particular platform may choose to ignore any hint.
129  *
130  * availability: version 0.2
131  *
132  */
133  void (*powerHint)(struct power_module *module, power_hint_t hint,
134  void *data);
135 
136  /*
137  * (*setFeature) is called to turn on or off a particular feature
138  * depending on the state parameter. The possible features are:
139  *
140  * FEATURE_DOUBLE_TAP_TO_WAKE
141  *
142  * Enabling/Disabling this feature will allow/disallow the system
143  * to wake up by tapping the screen twice.
144  *
145  * availability: version 0.3
146  *
147  */
148  void (*setFeature)(struct power_module *module, feature_t feature, int state);
149 
151 
152 
153 __END_DECLS
154 
155 #endif // ANDROID_INCLUDE_HARDWARE_POWER_H
feature_t
Definition: power.h:52
void(* powerHint)(struct power_module *module, power_hint_t hint, void *data)
Definition: power.h:133
void(* setInteractive)(struct power_module *module, int on)
Definition: power.h:98
void(* setFeature)(struct power_module *module, feature_t feature, int state)
Definition: power.h:148
void(* init)(struct power_module *module)
Definition: power.h:70
struct power_module power_module_t
power_hint_t
Definition: power.h:41
struct hw_module_t common
Definition: power.h:62