tuna: Add Power HAL

* Add Power HAL for Tuna.

* Update cpufreq interactive governor params:
     min_sample_time = 100ms to cover bursts of graphics load
     go_hispeed_load = 40% to handle graphics loads

* Move screen off maximum frequency to generic cpufreq
  scaling_max_freq interface, set when turning screen on/off.

* Move cpufreq init from init.rc to Power HAL.

Change-Id: I12efd9b5fbfe89a487fac926b42ce1fe65980f7a

2 files changed, 149 insertions, 0 deletions

diff --git a/power/Android.mk b/power/Android.mk
new file mode 100644
index 0000000..da60418
--- /dev/null
+++ b/power/Android.mk
@@ -0,0 +1,27 @@
+# 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.
+
+
+LOCAL_PATH := $(call my-dir)
+
+# HAL module implemenation stored in
+# hw/<POWERS_HARDWARE_MODULE_ID>.<ro.hardware>.so
+include $(CLEAR_VARS)
+
+LOCAL_MODULE_PATH := $(TARGET_OUT_SHARED_LIBRARIES)/hw
+LOCAL_SHARED_LIBRARIES := liblog libcutils
+LOCAL_SRC_FILES := power_tuna.c
+LOCAL_MODULE := power.tuna
+LOCAL_MODULE_TAGS := optional
+include $(BUILD_SHARED_LIBRARY)
diff --git a/power/power_tuna.c b/power/power_tuna.c
new file mode 100644
index 0000000..b7d5ac2
--- /dev/null
+++ b/power/power_tuna.c
@@ -0,0 +1,122 @@
+/*
+ * 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 "Tuna PowerHAL"
+#include <utils/Log.h>
+
+#include <hardware/hardware.h>
+#include <hardware/power.h>
+
+/*
+ * Tuna uses 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 sysfs_write(char *path, char *s)
+{
+    char buf[80];
+    int len;
+    int fd = open(path, O_WRONLY);
+
+    if (fd < 0) {
+        strerror_r(errno, buf, sizeof(buf));
+        ALOGE("Error opening %s: %s\n", path, buf);
+        return;
+    }
+
+    len = write(fd, s, strlen(s));
+    if (len < 0) {
+        strerror_r(errno, buf, sizeof(buf));
+        ALOGE("Error writing to %s: %s\n", path, buf);
+    }
+
+    close(fd);
+}
+
+static void tuna_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);
+    }
+
+    /*
+     * cpufreq interactive governor: timer 20ms, min sample 100ms,
+     * hispeed 700MHz at load 40%
+     */
+
+    sysfs_write("/sys/devices/system/cpu/cpufreq/interactive/timer_rate",
+                "20000");
+    sysfs_write("/sys/devices/system/cpu/cpufreq/interactive/min_sample_time",
+                "100000");
+    sysfs_write("/sys/devices/system/cpu/cpufreq/interactive/hispeed_freq",
+                "700000");
+    sysfs_write("/sys/devices/system/cpu/cpufreq/interactive/go_hispeed_load",
+                "40");
+}
+
+static void tuna_power_set_interactive(struct power_module *module, int on)
+{
+    char buf[80];
+    int len;
+
+    /*
+     * Lower maximum frequency when screen is off.  CPU 0 and 1 share a
+     * cpufreq policy.
+     */
+
+    sysfs_write("/sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq",
+                on ? "1200000" : "700000");
+
+    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 = "Tuna Power HAL",
+        .author = "The Android Open Source Project",
+        .methods = &power_module_methods,
+    },
+
+    .init = tuna_power_init,
+    .setInteractive = tuna_power_set_interactive,
+};