diff --git a/core/java/android/os/IHardwareService.aidl b/core/java/android/os/IHardwareService.aidl
index aebcb3c049fc6..a6ef64739434b 100755
--- a/core/java/android/os/IHardwareService.aidl
+++ b/core/java/android/os/IHardwareService.aidl
@@ -32,6 +32,9 @@ interface IHardwareService
     // sets the brightness of the backlights (screen, keyboard, button) 0-255
     void setBacklights(int brightness);
 
+    // enables or disables automatic brightness mode
+    void setAutoBrightness(boolean on);
+
     // for the phone
     void setAttentionLight(boolean on);
 }
diff --git a/core/java/android/provider/Settings.java b/core/java/android/provider/Settings.java
index 688f37720541b..0bbd1fc57f209 100644
--- a/core/java/android/provider/Settings.java
+++ b/core/java/android/provider/Settings.java
@@ -1060,6 +1060,12 @@ public final class Settings {
          */
         public static final String SCREEN_BRIGHTNESS = "screen_brightness";
 
+        /**
+         * Control whether to enable automatic brightness mode.
+         * @hide
+         */
+        public static final String SCREEN_BRIGHTNESS_MODE = "screen_brightness_mode";
+
         /**
          * Control whether the process CPU usage meter should be shown.
          */
diff --git a/core/res/res/values/config.xml b/core/res/res/values/config.xml
index abb575c7d9d0c..117e1398e6ea9 100644
--- a/core/res/res/values/config.xml
+++ b/core/res/res/values/config.xml
@@ -81,4 +81,6 @@
         <item>30</item>
     </integer-array>
     
+    <!-- Flag indicating whether the device supports automatic brightness mode. -->
+    <bool name="config_automatic_brightness_available">false</bool>
 </resources>
diff --git a/packages/SettingsProvider/res/values/defaults.xml b/packages/SettingsProvider/res/values/defaults.xml
index 6b2044590e432..d5f1c614192fe 100644
--- a/packages/SettingsProvider/res/values/defaults.xml
+++ b/packages/SettingsProvider/res/values/defaults.xml
@@ -27,6 +27,7 @@
     <bool name="def_accelerometer_rotation">true</bool>
     <!-- Default screen brightness, from 0 to 255.  102 is 40%. -->
     <integer name="def_screen_brightness">102</integer>
+    <bool name="def_screen_brightness_automatic_mode">false</bool>
     <fraction name="def_window_animation_scale">100%</fraction>
     <fraction name="def_window_transition_scale">0%</fraction>
     
diff --git a/packages/SettingsProvider/src/com/android/providers/settings/DatabaseHelper.java b/packages/SettingsProvider/src/com/android/providers/settings/DatabaseHelper.java
index 2524a305b9736..f99eb5859d68d 100644
--- a/packages/SettingsProvider/src/com/android/providers/settings/DatabaseHelper.java
+++ b/packages/SettingsProvider/src/com/android/providers/settings/DatabaseHelper.java
@@ -71,7 +71,7 @@ public class DatabaseHelper extends SQLiteOpenHelper {
     // database gets upgraded properly. At a minimum, please confirm that 'upgradeVersion'
     // is properly propagated through your change.  Not doing so will result in a loss of user
     // settings.
-    private static final int DATABASE_VERSION = 39;
+    private static final int DATABASE_VERSION = 40;
 
     private Context mContext;
 
@@ -465,6 +465,22 @@ public class DatabaseHelper extends SQLiteOpenHelper {
             upgradeVersion = 39;
         }
 
+        if (upgradeVersion == 39) {
+            db.beginTransaction();
+            try {
+                String value =
+                        mContext.getResources().getBoolean(
+                        R.bool.def_screen_brightness_automatic_mode) ? "1" : "0";
+                db.execSQL("INSERT OR IGNORE INTO system(name,value) values('" +
+                        Settings.System.SCREEN_BRIGHTNESS_MODE + "','" + value + "');");
+                db.setTransactionSuccessful();
+            } finally {
+                db.endTransaction();
+            }
+
+            upgradeVersion = 40;
+        }
+
         if (upgradeVersion != currentVersion) {
             Log.w(TAG, "Got stuck trying to upgrade from version " + upgradeVersion
                     + ", must wipe the settings provider");
@@ -701,6 +717,9 @@ public class DatabaseHelper extends SQLiteOpenHelper {
         loadIntegerSetting(stmt, Settings.System.SCREEN_BRIGHTNESS,
                 R.integer.def_screen_brightness);
 
+        loadBooleanSetting(stmt, Settings.System.SCREEN_BRIGHTNESS_MODE,
+                R.bool.def_screen_brightness_automatic_mode);
+
         loadDefaultAnimationSettings(stmt);
 
         loadBooleanSetting(stmt, Settings.System.ACCELEROMETER_ROTATION,
diff --git a/services/java/com/android/server/HardwareService.java b/services/java/com/android/server/HardwareService.java
index 6ac72e0d57c81..01daae344197f 100755
--- a/services/java/com/android/server/HardwareService.java
+++ b/services/java/com/android/server/HardwareService.java
@@ -59,6 +59,8 @@ public class HardwareService extends IHardwareService.Stub {
     private boolean mAttentionLightOn;
     private boolean mPulsing;
 
+    private boolean mAutoBrightnessAvailable;
+
     private class Vibration implements IBinder.DeathRecipient {
         private final IBinder mToken;
         private final long    mTimeout;
@@ -129,6 +131,9 @@ public class HardwareService extends IHardwareService.Stub {
         IntentFilter filter = new IntentFilter();
         filter.addAction(Intent.ACTION_SCREEN_OFF);
         context.registerReceiver(mIntentReceiver, filter);
+
+        mAutoBrightnessAvailable = context.getResources().getBoolean(
+                com.android.internal.R.bool.config_automatic_brightness_available);
     }
 
     protected void finalize() throws Throwable {
@@ -302,6 +307,20 @@ public class HardwareService extends IHardwareService.Stub {
         setLight_native(mNativePointer, light, color, mode, onMS, offMS);
     }
 
+    public void setAutoBrightness(boolean on) {
+        if (mContext.checkCallingOrSelfPermission(android.Manifest.permission.HARDWARE_TEST)
+                != PackageManager.PERMISSION_GRANTED) {
+            throw new SecurityException("Requires HARDWARE_TEST permission");
+        }
+        setAutoBrightness_UNCHECKED(on);
+    }
+
+    void setAutoBrightness_UNCHECKED(boolean on) {
+        if (mAutoBrightnessAvailable) {
+            setAutoBrightness_native(mNativePointer, on);
+        }
+    }
+
     public void setAttentionLight(boolean on) {
         // Not worthy of a permission.  We shouldn't have a flashlight permission.
         synchronized (this) {
@@ -502,6 +521,7 @@ public class HardwareService extends IHardwareService.Stub {
     private static native int init_native();
     private static native void finalize_native(int ptr);
 
+    private static native void setAutoBrightness_native(int ptr, boolean automatic);
     private static native void setLight_native(int ptr, int light, int color, int mode,
             int onMS, int offMS);
 
diff --git a/services/java/com/android/server/PowerManagerService.java b/services/java/com/android/server/PowerManagerService.java
index ba65f01ef6862..e64a1def0f36c 100644
--- a/services/java/com/android/server/PowerManagerService.java
+++ b/services/java/com/android/server/PowerManagerService.java
@@ -52,6 +52,7 @@ import android.util.Log;
 import android.view.WindowManagerPolicy;
 import static android.provider.Settings.System.DIM_SCREEN;
 import static android.provider.Settings.System.SCREEN_BRIGHTNESS;
+import static android.provider.Settings.System.SCREEN_BRIGHTNESS_MODE;
 import static android.provider.Settings.System.SCREEN_OFF_TIMEOUT;
 import static android.provider.Settings.System.STAY_ON_WHILE_PLUGGED_IN;
 
@@ -442,7 +443,11 @@ class PowerManagerService extends IPowerManager.Stub
 
         // turn everything on
         setPowerState(ALL_BRIGHT);
-        
+
+        // set auto brightness mode to user setting
+        boolean brightnessMode = Settings.System.getInt(resolver, SCREEN_BRIGHTNESS_MODE, 1) != 0;
+        mHardware.setAutoBrightness_UNCHECKED(brightnessMode);
+
         synchronized (mHandlerThread) {
             mInitComplete = true;
             mHandlerThread.notifyAll();
diff --git a/services/jni/com_android_server_HardwareService.cpp b/services/jni/com_android_server_HardwareService.cpp
index 22d4bd8766e89..a17e29fbf60d5 100644
--- a/services/jni/com_android_server_HardwareService.cpp
+++ b/services/jni/com_android_server_HardwareService.cpp
@@ -100,6 +100,18 @@ static void finalize_native(JNIEnv *env, jobject clazz, int ptr)
     free(devices);
 }
 
+static void setAutoBrightness_native(JNIEnv *env, jobject clazz, int ptr,
+        jboolean automatic)
+{
+    Devices* devices = (Devices*)ptr;
+
+    if (devices->lights[LIGHT_INDEX_BACKLIGHT] == NULL) {
+        return;
+    }
+
+    devices->lights[LIGHT_INDEX_BACKLIGHT]->set_als_mode(automatic ? 0 : 1);
+}
+
 static void setLight_native(JNIEnv *env, jobject clazz, int ptr,
         int light, int colorARGB, int flashMode, int onMS, int offMS)
 {
@@ -134,6 +146,7 @@ static void vibratorOff(JNIEnv *env, jobject clazz)
 static JNINativeMethod method_table[] = {
     { "init_native", "()I", (void*)init_native },
     { "finalize_native", "(I)V", (void*)finalize_native },
+    { "setAutoBrightness_native", "(IZ)V", (void*)setAutoBrightness_native },
     { "setLight_native", "(IIIIII)V", (void*)setLight_native },
     { "vibratorOn", "(J)V", (void*)vibratorOn },
     { "vibratorOff", "()V", (void*)vibratorOff }