Power HAL: Add initial header file and default/legacy implementation

Change-Id: I43a515a8ffe72a9c4e7d5f7470a5e73e76d5e1b1
Signed-off-by: Todd Poynor <toddpoynor@google.com>

1 files changed, 79 insertions, 0 deletions

diff --git a/include/hardware/power.h b/include/hardware/power.h
new file mode 100644
index 0000000..825a74a
--- /dev/null
+++ b/include/hardware/power.h
@@ -0,0 +1,79 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ANDROID_INCLUDE_HARDWARE_POWER_H
+#define ANDROID_INCLUDE_HARDWARE_POWER_H
+
+#include <stdint.h>
+#include <sys/cdefs.h>
+#include <sys/types.h>
+
+#include <hardware/hardware.h>
+
+__BEGIN_DECLS
+
+/**
+ * The id of this module
+ */
+#define POWER_HARDWARE_MODULE_ID "power"
+
+/**
+ * Every hardware module must have a data structure named HAL_MODULE_INFO_SYM
+ * and the fields of this data structure must begin with hw_module_t
+ * followed by module specific information.
+ */
+typedef struct power_module {
+    struct hw_module_t common;
+
+    /*
+     * (*init)() performs power management setup actions at runtime
+     * startup, such as to set default cpufreq parameters.
+     */
+    void (*init)(struct power_module *module);
+
+    /*
+     * (*setInteractive)() performs power management actions upon the
+     * system entering interactive state (that is, the system is awake
+     * and ready for interaction, often with UI devices such as
+     * display and touchscreen enabled) or non-interactive state (the
+     * system appears asleep, display usually turned off).  The
+     * non-interactive state is usually entered after a period of
+     * inactivity, in order to conserve battery power during
+     * such inactive periods.
+     *
+     * Typical actions are to turn on or off devices and adjust
+     * cpufreq parameters.  This function may also call the
+     * appropriate interfaces to allow the kernel to suspend the
+     * system to low-power sleep state when entering non-interactive
+     * state, and to disallow low-power suspend when the system is in
+     * interactive state.  When low-power suspend state is allowed, the
+     * kernel may suspend the system whenever no wakelocks are held.
+     *
+     * on is non-zero when the system is transitioning to an
+     * interactive / awake state, and zero when transitioning to a
+     * non-interactive / asleep state.
+     *
+     * This function is called to enter non-interactive state after
+     * turning off the screen (if present), and called to enter
+     * interactive state prior to turning on the screen.
+     */
+    void (*setInteractive)(struct power_module *module, int on);
+} power_module_t;
+
+
+__END_DECLS
+
+#endif  // ANDROID_INCLUDE_HARDWARE_POWER_H