libsuspend: create new library to handle triggering suspend

libsuspend provides functions autosuspend_enable() and
autosuspend_disable() to trigger suspend on a variety of different
kernels.

Change-Id: I5dc28fb51532fa7c514330f1cfde7698d31d734c

libsuspend/Android.mk

@@ -0,0 +1,23 @@
+# Copyright 2012 The Android Open Source Project
+
+LOCAL_PATH:= $(call my-dir)
+
+libsuspend_src_files := \
+	autosuspend.c \
+	autosuspend_autosleep.c \
+	autosuspend_earlysuspend.c \
+	autosuspend_wakeup_count.c \
+
+libsuspend_libraries := \
+	liblog libcutils
+
+include $(CLEAR_VARS)
+
+LOCAL_SRC_FILES := $(libsuspend_src_files)
+LOCAL_MODULE := libsuspend
+LOCAL_MODULE_TAGS := optional
+LOCAL_EXPORT_C_INCLUDE_DIRS := $(LOCAL_PATH)/include
+LOCAL_C_INCLUDES += $(LOCAL_PATH)/include
+LOCAL_SHARED_LIBRARIES := $(libsuspend_libraries)
+#LOCAL_CFLAGS += -DLOG_NDEBUG=0
+include $(BUILD_SHARED_LIBRARY)

libsuspend/autosuspend.c

@@ -0,0 +1,109 @@
+/*
+ * 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 <stdbool.h>
+
+#define LOG_TAG "libsuspend"
+#include <cutils/log.h>
+
+#include <suspend/autosuspend.h>
+
+#include "autosuspend_ops.h"
+
+static struct autosuspend_ops *autosuspend_ops;
+static bool autosuspend_enabled;
+static bool autosuspend_inited;
+
+static int autosuspend_init(void)
+{
+    if (autosuspend_inited) {
+        return 0;
+    }
+
+    autosuspend_inited = true;
+
+    autosuspend_ops = autosuspend_earlysuspend_init();
+    if (autosuspend_ops) {
+        goto out;
+    }
+
+    autosuspend_ops = autosuspend_autosleep_init();
+    if (autosuspend_ops) {
+        goto out;
+    }
+
+    autosuspend_ops = autosuspend_wakeup_count_init();
+    if (autosuspend_ops) {
+        goto out;
+    }
+
+    if (!autosuspend_ops) {
+        ALOGE("failed to initialize autosuspend\n");
+        return -1;
+    }
+
+out:
+    ALOGV("autosuspend initialized\n");
+    return 0;
+}
+
+int autosuspend_enable(void)
+{
+    int ret;
+
+    ret = autosuspend_init();
+    if (ret) {
+        return ret;
+    }
+
+    ALOGV("autosuspend_enable\n");
+
+    if (autosuspend_enabled) {
+        return 0;
+    }
+
+    ret = autosuspend_ops->enable();
+    if (ret) {
+        return ret;
+    }
+
+    autosuspend_enabled = true;
+    return 0;
+}
+
+int autosuspend_disable(void)
+{
+    int ret;
+
+    ret = autosuspend_init();
+    if (ret) {
+        return ret;
+    }
+
+    ALOGV("autosuspend_disable\n");
+
+    if (!autosuspend_enabled) {
+        return 0;
+    }
+
+    ret = autosuspend_ops->disable();
+    if (ret) {
+        return ret;
+    }
+
+    autosuspend_enabled = false;
+    return 0;
+}

libsuspend/autosuspend_autosleep.c

@@ -0,0 +1,99 @@
+/*
+ * 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 <fcntl.h>
+#include <stddef.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#define LOG_TAG "libsuspend"
+#include <cutils/log.h>
+
+#include "autosuspend_ops.h"
+
+#define SYS_POWER_AUTOSLEEP "/sys/power/autosleep"
+
+static int autosleep_fd;
+static const char *sleep_state = "mem";
+static const char *on_state = "off";
+
+static int autosuspend_autosleep_enable(void)
+{
+    char buf[80];
+    int ret;
+
+    ALOGV("autosuspend_autosleep_enable\n");
+
+    ret = write(autosleep_fd, sleep_state, strlen(sleep_state));
+    if (ret < 0) {
+        strerror_r(errno, buf, sizeof(buf));
+        ALOGE("Error writing to %s: %s\n", SYS_POWER_AUTOSLEEP, buf);
+        goto err;
+    }
+
+    ALOGV("autosuspend_autosleep_enable done\n");
+
+    return 0;
+
+err:
+    return ret;
+}
+
+static int autosuspend_autosleep_disable(void)
+{
+    char buf[80];
+    int ret;
+
+    ALOGV("autosuspend_autosleep_disable\n");
+
+    ret = write(autosleep_fd, on_state, strlen(on_state));
+    if (ret < 0) {
+        strerror_r(errno, buf, sizeof(buf));
+        ALOGE("Error writing to %s: %s\n", SYS_POWER_AUTOSLEEP, buf);
+        goto err;
+    }
+
+    ALOGV("autosuspend_autosleep_disable done\n");
+
+    return 0;
+
+err:
+    return ret;
+}
+
+struct autosuspend_ops autosuspend_autosleep_ops = {
+        .enable = autosuspend_autosleep_enable,
+        .disable = autosuspend_autosleep_disable,
+};
+
+struct autosuspend_ops *autosuspend_autosleep_init(void)
+{
+    int ret;
+    char buf[80];
+
+    autosleep_fd = open(SYS_POWER_AUTOSLEEP, O_WRONLY);
+    if (autosleep_fd < 0) {
+        strerror_r(errno, buf, sizeof(buf));
+        ALOGE("Error opening %s: %s\n", SYS_POWER_AUTOSLEEP, buf);
+        return NULL;
+    }
+
+    ALOGI("Selected autosleep\n");
+    return &autosuspend_autosleep_ops;
+}

libsuspend/autosuspend_earlysuspend.c

@@ -0,0 +1,113 @@
+/*
+ * 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 <fcntl.h>
+#include <stddef.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#define LOG_TAG "libsuspend"
+#include <cutils/log.h>
+
+#include "autosuspend_ops.h"
+
+#define EARLYSUSPEND_SYS_POWER_STATE "/sys/power/state"
+#define EARLYSUSPEND_WAIT_FOR_FB_SLEEP "/sys/power/wait_for_fb_sleep"
+#define EARLYSUSPEND_WAIT_FOR_FB_WAKE "/sys/power/wait_for_fb_wake"
+
+
+static int sPowerStatefd;
+static const char *pwr_state_mem = "mem";
+static const char *pwr_state_on = "on";
+
+static int autosuspend_earlysuspend_enable(void)
+{
+    char buf[80];
+    int ret;
+
+    ALOGV("autosuspend_earlysuspend_enable\n");
+
+    ret = write(sPowerStatefd, pwr_state_mem, strlen(pwr_state_mem));
+    if (ret < 0) {
+        strerror_r(errno, buf, sizeof(buf));
+        ALOGE("Error writing to %s: %s\n", EARLYSUSPEND_SYS_POWER_STATE, buf);
+        goto err;
+    }
+
+    ALOGV("autosuspend_earlysuspend_enable done\n");
+
+    return 0;
+
+err:
+    return ret;
+}
+
+static int autosuspend_earlysuspend_disable(void)
+{
+    char buf[80];
+    int ret;
+
+    ALOGV("autosuspend_earlysuspend_disable\n");
+
+    ret = write(sPowerStatefd, pwr_state_on, strlen(pwr_state_on));
+    if (ret < 0) {
+        strerror_r(errno, buf, sizeof(buf));
+        ALOGE("Error writing to %s: %s\n", EARLYSUSPEND_SYS_POWER_STATE, buf);
+        goto err;
+    }
+
+    ALOGV("autosuspend_earlysuspend_disable done\n");
+
+    return 0;
+
+err:
+    return ret;
+}
+
+struct autosuspend_ops autosuspend_earlysuspend_ops = {
+        .enable = autosuspend_earlysuspend_enable,
+        .disable = autosuspend_earlysuspend_disable,
+};
+
+struct autosuspend_ops *autosuspend_earlysuspend_init(void)
+{
+    char buf[80];
+    int ret;
+
+    ret = access(EARLYSUSPEND_WAIT_FOR_FB_SLEEP, F_OK);
+    if (ret < 0) {
+        return NULL;
+    }
+
+    ret = access(EARLYSUSPEND_WAIT_FOR_FB_WAKE, F_OK);
+    if (ret < 0) {
+        return NULL;
+    }
+
+    sPowerStatefd = open(EARLYSUSPEND_SYS_POWER_STATE, O_RDWR);
+
+    if (sPowerStatefd < 0) {
+        strerror_r(errno, buf, sizeof(buf));
+        ALOGE("Error opening %s: %s\n", EARLYSUSPEND_SYS_POWER_STATE, buf);
+        return NULL;
+    }
+
+    ALOGI("Selected early suspend\n");
+    return &autosuspend_earlysuspend_ops;
+}

libsuspend/autosuspend_ops.h

@@ -0,0 +1,29 @@
+/*
+ * 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 _LIBSUSPEND_AUTOSUSPEND_OPS_H_
+#define _LIBSUSPEND_AUTOSUSPEND_OPS_H_
+
+struct autosuspend_ops {
+    int (*enable)(void);
+    int (*disable)(void);
+};
+
+struct autosuspend_ops *autosuspend_autosleep_init(void);
+struct autosuspend_ops *autosuspend_earlysuspend_init(void);
+struct autosuspend_ops *autosuspend_wakeup_count_init(void);
+
+#endif

libsuspend/autosuspend_wakeup_count.c

@@ -0,0 +1,182 @@
+/*
+ * 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 <fcntl.h>
+#include <pthread.h>
+#include <semaphore.h>
+#include <stddef.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#define LOG_TAG "libsuspend"
+#include <cutils/log.h>
+
+#include "autosuspend_ops.h"
+
+#define SYS_POWER_STATE "/sys/power/state"
+#define SYS_POWER_WAKEUP_COUNT "/sys/power/wakeup_count"
+
+static int state_fd;
+static int wakeup_count_fd;
+static pthread_t suspend_thread;
+static sem_t suspend_lockout;
+static const char *sleep_state = "mem";
+
+static void *suspend_thread_func(void *arg)
+{
+    char buf[80];
+    char wakeup_count[20];
+    int wakeup_count_len;
+    int ret;
+
+    while (1) {
+        usleep(100000);
+        ALOGV("%s: read wakeup_count\n", __func__);
+        lseek(wakeup_count_fd, 0, SEEK_SET);
+        wakeup_count_len = read(wakeup_count_fd, wakeup_count, sizeof(wakeup_count));
+        if (wakeup_count_len < 0) {
+            strerror_r(errno, buf, sizeof(buf));
+            ALOGE("Error reading from %s: %s\n", SYS_POWER_WAKEUP_COUNT, buf);
+            wakeup_count_len = 0;
+            continue;
+        }
+        if (!wakeup_count_len) {
+            ALOGE("Empty wakeup count\n");
+            continue;
+        }
+
+        ALOGV("%s: wait\n", __func__);
+        ret = sem_wait(&suspend_lockout);
+        if (ret < 0) {
+            strerror_r(errno, buf, sizeof(buf));
+            ALOGE("Error waiting on semaphore: %s\n", buf);
+            continue;
+        }
+
+        ALOGV("%s: write %*s to wakeup_count\n", __func__, wakeup_count_len, wakeup_count);
+        ret = write(wakeup_count_fd, wakeup_count, wakeup_count_len);
+        if (ret < 0) {
+            strerror_r(errno, buf, sizeof(buf));
+            ALOGE("Error writing to %s: %s\n", SYS_POWER_WAKEUP_COUNT, buf);
+        } else {
+            ALOGV("%s: write %s to %s\n", __func__, sleep_state, SYS_POWER_STATE);
+            ret = write(state_fd, sleep_state, strlen(sleep_state));
+            if (ret < 0) {
+                strerror_r(errno, buf, sizeof(buf));
+                ALOGE("Error writing to %s: %s\n", SYS_POWER_STATE, buf);
+            }
+        }
+
+        ALOGV("%s: release sem\n", __func__);
+        ret = sem_post(&suspend_lockout);
+        if (ret < 0) {
+            strerror_r(errno, buf, sizeof(buf));
+            ALOGE("Error releasing semaphore: %s\n", buf);
+        }
+    }
+    return NULL;
+}
+
+static int autosuspend_wakeup_count_enable(void)
+{
+    char buf[80];
+    int ret;
+
+    ALOGV("autosuspend_wakeup_count_enable\n");
+
+    ret = sem_post(&suspend_lockout);
+
+    if (ret < 0) {
+        strerror_r(errno, buf, sizeof(buf));
+        ALOGE("Error changing semaphore: %s\n", buf);
+    }
+
+    ALOGV("autosuspend_wakeup_count_enable done\n");
+
+    return ret;
+}
+
+static int autosuspend_wakeup_count_disable(void)
+{
+    char buf[80];
+    int ret;
+
+    ALOGV("autosuspend_wakeup_count_disable\n");
+
+    ret = sem_wait(&suspend_lockout);
+
+    if (ret < 0) {
+        strerror_r(errno, buf, sizeof(buf));
+        ALOGE("Error changing semaphore: %s\n", buf);
+    }
+
+    ALOGV("autosuspend_wakeup_count_disable done\n");
+
+    return ret;
+}
+
+struct autosuspend_ops autosuspend_wakeup_count_ops = {
+        .enable = autosuspend_wakeup_count_enable,
+        .disable = autosuspend_wakeup_count_disable,
+};
+
+struct autosuspend_ops *autosuspend_wakeup_count_init(void)
+{
+    int ret;
+    char buf[80];
+
+    state_fd = open(SYS_POWER_STATE, O_RDWR);
+    if (state_fd < 0) {
+        strerror_r(errno, buf, sizeof(buf));
+        ALOGE("Error opening %s: %s\n", SYS_POWER_STATE, buf);
+        goto err_open_state;
+    }
+
+    wakeup_count_fd = open(SYS_POWER_WAKEUP_COUNT, O_RDWR);
+    if (wakeup_count_fd < 0) {
+        strerror_r(errno, buf, sizeof(buf));
+        ALOGE("Error opening %s: %s\n", SYS_POWER_WAKEUP_COUNT, buf);
+        goto err_open_wakeup_count;
+    }
+
+    ret = sem_init(&suspend_lockout, 0, 0);
+    if (ret < 0) {
+        strerror_r(errno, buf, sizeof(buf));
+        ALOGE("Error creating semaphore: %s\n", buf);
+        goto err_sem_init;
+    }
+    ret = pthread_create(&suspend_thread, NULL, suspend_thread_func, NULL);
+    if (ret) {
+        strerror_r(ret, buf, sizeof(buf));
+        ALOGE("Error creating thread: %s\n", buf);
+        goto err_pthread_create;
+    }
+
+    ALOGI("Selected wakeup count\n");
+    return &autosuspend_wakeup_count_ops;
+
+err_pthread_create:
+    sem_destroy(&suspend_lockout);
+err_sem_init:
+    close(wakeup_count_fd);
+err_open_wakeup_count:
+    close(state_fd);
+err_open_state:
+    return NULL;
+}

libsuspend/include/suspend/autosuspend.h

@@ -0,0 +1,48 @@
+/*
+ * 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 _LIBSUSPEND_AUTOSUSPEND_H_
+#define _LIBSUSPEND_AUTOSUSPEND_H_
+
+#include <sys/cdefs.h>
+
+__BEGIN_DECLS
+
+/*
+ * autosuspend_enable
+ *
+ * Turn on autosuspend in the kernel, allowing it to enter suspend if no
+ * wakelocks/wakeup_sources are held.
+ *
+ *
+ *
+ * Returns 0 on success, -1 if autosuspend was not enabled.
+ */
+int autosuspend_enable(void);
+
+/*
+ * autosuspend_disable
+ *
+ * Turn off autosuspend in the kernel, preventing suspend and synchronizing
+ * with any in-progress resume.
+ *
+ * Returns 0 on success, -1 if autosuspend was not disabled.
+ */
+int autosuspend_disable(void);
+
+__END_DECLS
+
+#endif