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

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

4 files changed, 185 insertions, 1 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
diff --git a/modules/Android.mk b/modules/Android.mk
index c4c66da..b8b83ba 100644
--- a/modules/Android.mk
+++ b/modules/Android.mk
@@ -1,2 +1,2 @@
-hardware_modules := gralloc hwcomposer audio nfc local_time
+hardware_modules := gralloc hwcomposer audio nfc local_time power
 include $(call all-named-subdir-makefiles,$(hardware_modules))
diff --git a/modules/power/Android.mk b/modules/power/Android.mk
new file mode 100644
index 0000000..50ab221
--- /dev/null
+++ b/modules/power/Android.mk
@@ -0,0 +1,25 @@
+# Copyright (C) 2011 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.
+
+LOCAL_PATH := $(call my-dir)
+
+include $(CLEAR_VARS)
+
+LOCAL_MODULE := power.default
+LOCAL_MODULE_PATH := $(TARGET_OUT_SHARED_LIBRARIES)/hw
+LOCAL_SRC_FILES := power.c
+LOCAL_SHARED_LIBRARIES := liblog
+LOCAL_MODULE_TAGS := optional
+
+include $(BUILD_SHARED_LIBRARY)
diff --git a/modules/power/power.c b/modules/power/power.c
new file mode 100644
index 0000000..ef3fe94
--- /dev/null
+++ b/modules/power/power.c
@@ -0,0 +1,80 @@
+/*
+ * 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.
+ */
+#include <errno.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+#define LOG_TAG "Legacy PowerHAL"
+#include <utils/Log.h>
+
+#include <hardware/hardware.h>
+#include <hardware/power.h>
+
+/*
+ * This module implements the legacy interface for requesting early
+ * suspend and late resume
+ */
+
+#define LEGACY_SYS_POWER_STATE "/sys/power/state"
+
+static int sPowerStatefd;
+static const char *pwr_states[] = { "mem", "on" };
+
+static void power_init(struct power_module *module)
+{
+    char buf[80];
+
+    sPowerStatefd = open(LEGACY_SYS_POWER_STATE, O_RDWR);
+
+    if (sPowerStatefd < 0) {
+        strerror_r(errno, buf, sizeof(buf));
+        ALOGE("Error opening %s: %s\n", LEGACY_SYS_POWER_STATE, buf);
+    }
+}
+
+static void power_set_interactive(struct power_module *module, int on)
+{
+    char buf[80];
+    int len;
+
+    len = write(sPowerStatefd, pwr_states[!!on], strlen(pwr_states[!!on]));
+    if (len < 0) {
+        strerror_r(errno, buf, sizeof(buf));
+        ALOGE("Error writing to %s: %s\n", LEGACY_SYS_POWER_STATE, buf);
+    }
+}
+
+
+static struct hw_module_methods_t power_module_methods = {
+    .open = NULL,
+};
+
+struct power_module HAL_MODULE_INFO_SYM = {
+    .common = {
+        .tag = HARDWARE_MODULE_TAG,
+        .version_major = 1,
+        .version_minor = 0,
+        .id = POWER_HARDWARE_MODULE_ID,
+        .name = "Default Power HAL",
+        .author = "The Android Open Source Project",
+        .methods = &power_module_methods,
+    },
+
+    .init = power_init,
+    .setInteractive = power_set_interactive,
+};