diff --git a/api/current.txt b/api/current.txt
index d54b7fd117085..55f3b4751e232 100644
--- a/api/current.txt
+++ b/api/current.txt
@@ -5529,6 +5529,8 @@ package android.app {
     method public void enableCarMode(int);
     method public int getCurrentModeType();
     method public int getNightMode();
+    method public boolean isNightModeLocked();
+    method public boolean isUiModeLocked();
     method public void setNightMode(int);
     field public static java.lang.String ACTION_ENTER_CAR_MODE;
     field public static java.lang.String ACTION_ENTER_DESK_MODE;
diff --git a/api/system-current.txt b/api/system-current.txt
index 2ea5ebb5a2972..c50fe01050bb3 100644
--- a/api/system-current.txt
+++ b/api/system-current.txt
@@ -133,6 +133,7 @@ package android {
     field public static final java.lang.String MODIFY_AUDIO_ROUTING = "android.permission.MODIFY_AUDIO_ROUTING";
     field public static final java.lang.String MODIFY_AUDIO_SETTINGS = "android.permission.MODIFY_AUDIO_SETTINGS";
     field public static final java.lang.String MODIFY_CELL_BROADCASTS = "android.permission.MODIFY_CELL_BROADCASTS";
+    field public static final java.lang.String MODIFY_DAY_NIGHT_MODE = "android.permission.MODIFY_DAY_NIGHT_MODE";
     field public static final java.lang.String MODIFY_NETWORK_ACCOUNTING = "android.permission.MODIFY_NETWORK_ACCOUNTING";
     field public static final java.lang.String MODIFY_PARENTAL_CONTROLS = "android.permission.MODIFY_PARENTAL_CONTROLS";
     field public static final java.lang.String MODIFY_PHONE_STATE = "android.permission.MODIFY_PHONE_STATE";
@@ -5648,6 +5649,8 @@ package android.app {
     method public void enableCarMode(int);
     method public int getCurrentModeType();
     method public int getNightMode();
+    method public boolean isNightModeLocked();
+    method public boolean isUiModeLocked();
     method public void setNightMode(int);
     field public static java.lang.String ACTION_ENTER_CAR_MODE;
     field public static java.lang.String ACTION_ENTER_DESK_MODE;
diff --git a/core/java/android/app/IUiModeManager.aidl b/core/java/android/app/IUiModeManager.aidl
index 7e9873e5f2f27..cae54b6c0611f 100644
--- a/core/java/android/app/IUiModeManager.aidl
+++ b/core/java/android/app/IUiModeManager.aidl
@@ -51,4 +51,14 @@ interface IUiModeManager {
      * 2 for night, and 3 for automatic mode switching.
      */
     int getNightMode();
+
+    /**
+     * Tells if UI mode is locked or not.
+     */
+    boolean isUiModeLocked();
+
+    /**
+     * Tells if Night mode is locked or not.
+     */
+    boolean isNightModeLocked();
 }
diff --git a/core/java/android/app/UiModeManager.java b/core/java/android/app/UiModeManager.java
index 0f6ce1227ca45..44164158c7b47 100644
--- a/core/java/android/app/UiModeManager.java
+++ b/core/java/android/app/UiModeManager.java
@@ -233,4 +233,35 @@ public class UiModeManager {
         }
         return -1;
     }
+
+    /**
+     * @return If UI mode is locked or not. When UI mode is locked, calls to change UI mode
+     *         like {@link #enableCarMode(int)} will silently fail.
+     */
+    public boolean isUiModeLocked() {
+        if (mService != null) {
+            try {
+                return mService.isUiModeLocked();
+            } catch (RemoteException e) {
+                Log.e(TAG, "isUiModeLocked: RemoteException", e);
+            }
+        }
+        return true;
+    }
+
+    /**
+     * @return If Night mode is locked or not. When Night mode is locked, changing Night mode
+     *         is only allowed to privileged system components and normal application's call
+     *         to change Night mode using {@link #setNightMode(int)} will silently fail.
+     */
+    public boolean isNightModeLocked() {
+        if (mService != null) {
+            try {
+                return mService.isNightModeLocked();
+            } catch (RemoteException e) {
+                Log.e(TAG, "isNightModeLocked: RemoteException", e);
+            }
+        }
+        return true;
+    }
 }
diff --git a/core/res/AndroidManifest.xml b/core/res/AndroidManifest.xml
index 2940f6c7fc10e..02d298eddfb27 100644
--- a/core/res/AndroidManifest.xml
+++ b/core/res/AndroidManifest.xml
@@ -2712,6 +2712,13 @@
     <permission android:name="android.permission.DISPATCH_NFC_MESSAGE"
                 android:protectionLevel="signature|privileged" />
 
+    <!-- @SystemApi Allows changing day / night mode when system is configured with
+         config_lockDayNightMode set to true. If requesting app does not have permission,
+         it will be ignored.
+        @hide -->
+    <permission android:name="android.permission.MODIFY_DAY_NIGHT_MODE"
+                android:protectionLevel="signature|privileged" />
+
     <!-- The system process is explicitly the only one allowed to launch the
          confirmation UI for full backup/restore -->
     <uses-permission android:name="android.permission.CONFIRM_FULL_BACKUP"/>
diff --git a/core/res/res/values/config.xml b/core/res/res/values/config.xml
index d9e04728badda..caa20dc454a04 100644
--- a/core/res/res/values/config.xml
+++ b/core/res/res/values/config.xml
@@ -716,6 +716,13 @@
 
     <bool name="config_carDockEnablesAccelerometer">true</bool>
 
+    <!--  Control whether to launch Car dock home app when user presses home button or when
+          car dock intent is fired.
+          In mobile device, usually separate home app is expected in car mode, and this should be
+          enabled. But in environments like real car, default home app may be enough, and in that
+          case, this can be disabled (set to false). -->
+    <bool name="config_enableCarDockHomeLaunch">true</bool>
+
     <!-- HDMI behavior -->
 
     <!-- The number of degrees to rotate the display when the device has HDMI connected
@@ -733,6 +740,15 @@
          Any other values will have surprising consequences. -->
     <integer name="config_defaultUiModeType">1</integer>
 
+    <!--  Control whether to lock UI mode to what is selected from config_defaultUiModeType.
+          Once UI mode is locked, applications cannot change it anymore. -->
+    <bool name="config_lockUiMode">false</bool>
+
+    <!--  Control whether to lock day/night mode change from normal application. When it is
+          true, day / night mode change is only allowed to apps with MODIFY_DAY_NIGHT_MODE
+          permission. -->
+    <bool name="config_lockDayNightMode">false</bool>
+
     <!-- Control the default night mode to use when there is no other mode override set.
          One of the following values (see UiModeManager.java):
              0 - MODE_NIGHT_AUTO
diff --git a/core/res/res/values/symbols.xml b/core/res/res/values/symbols.xml
index 3860f68f12925..16c9db1c7f2c2 100644
--- a/core/res/res/values/symbols.xml
+++ b/core/res/res/values/symbols.xml
@@ -1476,11 +1476,14 @@
   <java-symbol type="bool" name="config_carDockEnablesAccelerometer" />
   <java-symbol type="bool" name="config_deskDockEnablesAccelerometer" />
   <java-symbol type="bool" name="config_disableMenuKeyInLockScreen" />
+  <java-symbol type="bool" name="config_enableCarDockHomeLaunch" />
   <java-symbol type="bool" name="config_enableLockBeforeUnlockScreen" />
   <java-symbol type="bool" name="config_enableLockScreenRotation" />
   <java-symbol type="bool" name="config_enableLockScreenTranslucentDecor" />
   <java-symbol type="bool" name="config_enableTranslucentDecor" />
   <java-symbol type="bool" name="config_lidControlsSleep" />
+  <java-symbol type="bool" name="config_lockDayNightMode" />
+  <java-symbol type="bool" name="config_lockUiMode" />
   <java-symbol type="bool" name="config_reverseDefaultRotation" />
   <java-symbol type="bool" name="config_showNavigationBar" />
   <java-symbol type="bool" name="config_supportAutoRotation" />
diff --git a/services/core/java/com/android/server/UiModeManagerService.java b/services/core/java/com/android/server/UiModeManagerService.java
index 0b67ad81b379e..6f713cdfebbe0 100644
--- a/services/core/java/com/android/server/UiModeManagerService.java
+++ b/services/core/java/com/android/server/UiModeManagerService.java
@@ -57,7 +57,6 @@ final class UiModeManagerService extends SystemService {
     private static final boolean LOG = false;
 
     // Enable launching of applications when entering the dock.
-    private static final boolean ENABLE_LAUNCH_CAR_DOCK_APP = true;
     private static final boolean ENABLE_LAUNCH_DESK_DOCK_APP = true;
 
     final Object mLock = new Object();
@@ -76,6 +75,13 @@ final class UiModeManagerService extends SystemService {
     private boolean mComputedNightMode;
     private int mCarModeEnableFlags;
 
+    // flag set by resource, whether to enable Car dock launch when starting car mode.
+    private boolean mEnableCarDockLaunch = true;
+    // flag set by resource, whether to lock UI mode to the default one or not.
+    private boolean mUiModeLocked = false;
+    // flag set by resource, whether to night mode change for normal all or not.
+    private boolean mNightModeLocked = false;
+
     int mCurUiMode = 0;
     private int mSetUiMode = 0;
     private boolean mHoldingConfiguration = false;
@@ -176,6 +182,10 @@ final class UiModeManagerService extends SystemService {
                 com.android.internal.R.integer.config_carDockKeepsScreenOn) == 1);
         mDeskModeKeepsScreenOn = (res.getInteger(
                 com.android.internal.R.integer.config_deskDockKeepsScreenOn) == 1);
+        mEnableCarDockLaunch = res.getBoolean(
+                com.android.internal.R.bool.config_enableCarDockHomeLaunch);
+        mUiModeLocked = res.getBoolean(com.android.internal.R.bool.config_lockUiMode);
+        mNightModeLocked = res.getBoolean(com.android.internal.R.bool.config_lockDayNightMode);
 
         final PackageManager pm = context.getPackageManager();
         mTelevision = pm.hasSystemFeature(PackageManager.FEATURE_TELEVISION)
@@ -199,6 +209,10 @@ final class UiModeManagerService extends SystemService {
     private final IBinder mService = new IUiModeManager.Stub() {
         @Override
         public void enableCarMode(int flags) {
+            if (isUiModeLocked()) {
+                Slog.e(TAG, "enableCarMode while UI mode is locked");
+                return;
+            }
             final long ident = Binder.clearCallingIdentity();
             try {
                 synchronized (mLock) {
@@ -214,6 +228,10 @@ final class UiModeManagerService extends SystemService {
 
         @Override
         public void disableCarMode(int flags) {
+            if (isUiModeLocked()) {
+                Slog.e(TAG, "disableCarMode while UI mode is locked");
+                return;
+            }
             final long ident = Binder.clearCallingIdentity();
             try {
                 synchronized (mLock) {
@@ -241,6 +259,13 @@ final class UiModeManagerService extends SystemService {
 
         @Override
         public void setNightMode(int mode) {
+            if (isNightModeLocked() &&  (getContext().checkCallingOrSelfPermission(
+                    android.Manifest.permission.MODIFY_DAY_NIGHT_MODE)
+                    != PackageManager.PERMISSION_GRANTED)) {
+                Slog.e(TAG,
+                        "Night mode locked, requires MODIFY_DAY_NIGHT_MODE permission");
+                return;
+            }
             switch (mode) {
                 case UiModeManager.MODE_NIGHT_NO:
                 case UiModeManager.MODE_NIGHT_YES:
@@ -272,6 +297,20 @@ final class UiModeManagerService extends SystemService {
             }
         }
 
+        @Override
+        public boolean isUiModeLocked() {
+            synchronized (mLock) {
+                return mUiModeLocked;
+            }
+        }
+
+        @Override
+        public boolean isNightModeLocked() {
+            synchronized (mLock) {
+                return mNightModeLocked;
+            }
+        }
+
         @Override
         protected void dump(FileDescriptor fd, PrintWriter pw, String[] args) {
             if (getContext().checkCallingOrSelfPermission(android.Manifest.permission.DUMP)
@@ -293,10 +332,13 @@ final class UiModeManagerService extends SystemService {
             pw.print("  mDockState="); pw.print(mDockState);
                     pw.print(" mLastBroadcastState="); pw.println(mLastBroadcastState);
             pw.print("  mNightMode="); pw.print(mNightMode);
+                    pw.print(" mNightModeLocked="); pw.print(mNightModeLocked);
                     pw.print(" mCarModeEnabled="); pw.print(mCarModeEnabled);
                     pw.print(" mComputedNightMode="); pw.print(mComputedNightMode);
-                    pw.print(" mCarModeEnableFlags="); pw.println(mCarModeEnableFlags);
+                    pw.print(" mCarModeEnableFlags="); pw.print(mCarModeEnableFlags);
+                    pw.print(" mEnableCarDockLaunch="); pw.println(mEnableCarDockLaunch);
             pw.print("  mCurUiMode=0x"); pw.print(Integer.toHexString(mCurUiMode));
+                    pw.print(" mUiModeLocked="); pw.print(mUiModeLocked);
                     pw.print(" mSetUiMode=0x"); pw.println(Integer.toHexString(mSetUiMode));
             pw.print("  mHoldingConfiguration="); pw.print(mHoldingConfiguration);
                     pw.print(" mSystemReady="); pw.println(mSystemReady);
@@ -356,7 +398,9 @@ final class UiModeManagerService extends SystemService {
 
     private void updateConfigurationLocked() {
         int uiMode = mDefaultUiModeType;
-        if (mTelevision) {
+        if (mUiModeLocked) {
+            // no-op, keeps default one
+        } else if (mTelevision) {
             uiMode = Configuration.UI_MODE_TYPE_TELEVISION;
         } else if (mWatch) {
             uiMode = Configuration.UI_MODE_TYPE_WATCH;
@@ -460,7 +504,7 @@ final class UiModeManagerService extends SystemService {
         } else {
             String category = null;
             if (mCarModeEnabled) {
-                if (ENABLE_LAUNCH_CAR_DOCK_APP
+                if (mEnableCarDockLaunch
                         && (enableFlags & UiModeManager.ENABLE_CAR_MODE_GO_CAR_HOME) != 0) {
                     category = Intent.CATEGORY_CAR_DOCK;
                 }
@@ -503,7 +547,7 @@ final class UiModeManagerService extends SystemService {
         if (UiModeManager.ACTION_ENTER_CAR_MODE.equals(action)) {
             // Only launch car home when car mode is enabled and the caller
             // has asked us to switch to it.
-            if (ENABLE_LAUNCH_CAR_DOCK_APP
+            if (mEnableCarDockLaunch
                     && (enableFlags & UiModeManager.ENABLE_CAR_MODE_GO_CAR_HOME) != 0) {
                 category = Intent.CATEGORY_CAR_DOCK;
             }
diff --git a/services/core/java/com/android/server/policy/PhoneWindowManager.java b/services/core/java/com/android/server/policy/PhoneWindowManager.java
index 639753a13b167..fbdb55ab73688 100644
--- a/services/core/java/com/android/server/policy/PhoneWindowManager.java
+++ b/services/core/java/com/android/server/policy/PhoneWindowManager.java
@@ -159,8 +159,7 @@ public class PhoneWindowManager implements WindowManagerPolicy {
     static final boolean SHOW_PROCESSES_ON_ALT_MENU = false;
 
     // Whether to allow dock apps with METADATA_DOCK_HOME to temporarily take over the Home key.
-    // No longer recommended for desk docks; still useful in car docks.
-    static final boolean ENABLE_CAR_DOCK_HOME_CAPTURE = true;
+    // No longer recommended for desk docks;
     static final boolean ENABLE_DESK_DOCK_HOME_CAPTURE = false;
 
     static final int SHORT_PRESS_POWER_NOTHING = 0;
@@ -317,6 +316,10 @@ public class PhoneWindowManager implements WindowManagerPolicy {
     int[] mNavigationBarHeightForRotation = new int[4];
     int[] mNavigationBarWidthForRotation = new int[4];
 
+    // Whether to allow dock apps with METADATA_DOCK_HOME to temporarily take over the Home key.
+    // This is for car dock and this is updated from resource.
+    private boolean mEnableCarDockHomeCapture = true;
+
     boolean mBootMessageNeedsHiding;
     KeyguardServiceDelegate mKeyguardDelegate;
     final Runnable mWindowManagerDrawCallback = new Runnable() {
@@ -1399,6 +1402,8 @@ public class PhoneWindowManager implements WindowManagerPolicy {
         mHomeIntent.addCategory(Intent.CATEGORY_HOME);
         mHomeIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK
                 | Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED);
+        mEnableCarDockHomeCapture = context.getResources().getBoolean(
+                com.android.internal.R.bool.config_enableCarDockHomeLaunch);
         mCarDockIntent =  new Intent(Intent.ACTION_MAIN, null);
         mCarDockIntent.addCategory(Intent.CATEGORY_CAR_DOCK);
         mCarDockIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK
@@ -6402,7 +6407,7 @@ public class PhoneWindowManager implements WindowManagerPolicy {
      * true:
      * <ul>
      *  <li>The device is not in either car mode or desk mode
-     *  <li>The device is in car mode but ENABLE_CAR_DOCK_HOME_CAPTURE is false
+     *  <li>The device is in car mode but mEnableCarDockHomeCapture is false
      *  <li>The device is in desk mode but ENABLE_DESK_DOCK_HOME_CAPTURE is false
      *  <li>The device is in car mode but there's no CAR_DOCK app with METADATA_DOCK_HOME
      *  <li>The device is in desk mode but there's no DESK_DOCK app with METADATA_DOCK_HOME
@@ -6416,7 +6421,7 @@ public class PhoneWindowManager implements WindowManagerPolicy {
         // is, when in car mode you should be taken to car home regardless
         // of whether we are actually in a car dock.
         if (mUiMode == Configuration.UI_MODE_TYPE_CAR) {
-            if (ENABLE_CAR_DOCK_HOME_CAPTURE) {
+            if (mEnableCarDockHomeCapture) {
                 intent = mCarDockIntent;
             }
         } else if (mUiMode == Configuration.UI_MODE_TYPE_DESK) {
@@ -6936,6 +6941,7 @@ public class PhoneWindowManager implements WindowManagerPolicy {
         pw.print(prefix); pw.print("mSupportAutoRotation="); pw.println(mSupportAutoRotation);
         pw.print(prefix); pw.print("mUiMode="); pw.print(mUiMode);
                 pw.print(" mDockMode="); pw.print(mDockMode);
+                pw.print(" mEnableCarDockHomeCapture="); pw.print(mEnableCarDockHomeCapture);
                 pw.print(" mCarDockRotation="); pw.print(mCarDockRotation);
                 pw.print(" mDeskDockRotation="); pw.println(mDeskDockRotation);
         pw.print(prefix); pw.print("mUserRotationMode="); pw.print(mUserRotationMode);