diff --git a/camera/Android.bp b/camera/Android.bp
index 2c01496..6878c20 100644
--- a/camera/Android.bp
+++ b/camera/Android.bp
@@ -119,6 +119,8 @@
         "aidl/android/hardware/camera2/ICameraDeviceCallbacks.aidl",
         "aidl/android/hardware/camera2/ICameraDeviceUser.aidl",
         "aidl/android/hardware/camera2/ICameraOfflineSession.aidl",
+        "aidl/android/hardware/camera2/ICameraInjectionCallback.aidl",
+        "aidl/android/hardware/camera2/ICameraInjectionSession.aidl",
     ],
     path: "aidl",
 }
diff --git a/camera/aidl/android/hardware/ICameraService.aidl b/camera/aidl/android/hardware/ICameraService.aidl
index 459ad15..873d738 100644
--- a/camera/aidl/android/hardware/ICameraService.aidl
+++ b/camera/aidl/android/hardware/ICameraService.aidl
@@ -20,6 +20,8 @@
 import android.hardware.ICameraClient;
 import android.hardware.camera2.ICameraDeviceUser;
 import android.hardware.camera2.ICameraDeviceCallbacks;
+import android.hardware.camera2.ICameraInjectionCallback;
+import android.hardware.camera2.ICameraInjectionSession;
 import android.hardware.camera2.params.VendorTagDescriptor;
 import android.hardware.camera2.params.VendorTagDescriptorCache;
 import android.hardware.camera2.utils.ConcurrentCameraIdCombination;
@@ -161,6 +163,9 @@
     boolean supportsCameraApi(String cameraId, int apiVersion);
     // Determines if a cameraId is a hidden physical camera of a logical multi-camera.
     boolean isHiddenPhysicalCamera(String cameraId);
+    // Inject the external camera to replace the internal camera session.
+    ICameraInjectionSession injectCamera(String packageName, String internalCamId,
+            String externalCamId, in ICameraInjectionCallback CameraInjectionCallback);
 
     void setTorchMode(String cameraId, boolean enabled, IBinder clientBinder);
 
diff --git a/camera/aidl/android/hardware/camera2/ICameraInjectionCallback.aidl b/camera/aidl/android/hardware/camera2/ICameraInjectionCallback.aidl
new file mode 100644
index 0000000..9791352
--- /dev/null
+++ b/camera/aidl/android/hardware/camera2/ICameraInjectionCallback.aidl
@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) 2021 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.
+ */
+
+package android.hardware.camera2;
+
+import android.hardware.camera2.ICameraInjectionSession;
+
+/**
+ * Binder interface used to call back the error state injected by the external camera,
+ * and camera service can be switched back to internal camera when binder signals process death.
+ *
+ * @hide
+ */
+interface ICameraInjectionCallback
+{
+    // Error codes for onInjectionError
+    // To indicate all invalid error codes
+    const int ERROR_INJECTION_INVALID_ERROR = -1;
+    // To indicate the camera injection session has encountered a fatal error, such as injection
+    // init failure, configure failure or injecting failure etc.
+    const int ERROR_INJECTION_SESSION = 0;
+    // To indicate the camera service has encountered a fatal error.
+    const int ERROR_INJECTION_SERVICE = 1;
+    // To indicate the injection camera does not support certain camera functions, such as
+    // unsupport stream format, no capture/record function or no multi-camera function etc.
+    // When this error occurs, the default processing is still in the inject state, and the app is
+    // notified to display an error message and a black screen.
+    const int ERROR_INJECTION_UNSUPPORTED = 2;
+
+    oneway void onInjectionError(int errorCode);
+}
diff --git a/camera/aidl/android/hardware/camera2/ICameraInjectionSession.aidl b/camera/aidl/android/hardware/camera2/ICameraInjectionSession.aidl
new file mode 100644
index 0000000..c31c30b
--- /dev/null
+++ b/camera/aidl/android/hardware/camera2/ICameraInjectionSession.aidl
@@ -0,0 +1,23 @@
+/*
+ * Copyright (C) 2021 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.
+ */
+
+package android.hardware.camera2;
+
+/** @hide */
+interface ICameraInjectionSession
+{
+    oneway void stopInjection();
+}
diff --git a/services/camera/libcameraservice/CameraService.cpp b/services/camera/libcameraservice/CameraService.cpp
index 65f27b1..3e6a7c7 100644
--- a/services/camera/libcameraservice/CameraService.cpp
+++ b/services/camera/libcameraservice/CameraService.cpp
@@ -91,6 +91,8 @@
 using hardware::ICameraServiceListener;
 using hardware::camera::common::V1_0::CameraDeviceStatus;
 using hardware::camera::common::V1_0::TorchModeStatus;
+using hardware::camera2::ICameraInjectionCallback;
+using hardware::camera2::ICameraInjectionSession;
 using hardware::camera2::utils::CameraIdAndSessionConfiguration;
 using hardware::camera2::utils::ConcurrentCameraIdCombination;
 
@@ -127,6 +129,8 @@
         sCameraSendSystemEventsPermission("android.permission.CAMERA_SEND_SYSTEM_EVENTS");
 static const String16 sCameraOpenCloseListenerPermission(
         "android.permission.CAMERA_OPEN_CLOSE_LISTENER");
+static const String16
+        sCameraInjectExternalCameraPermission("android.permission.CAMERA_INJECT_EXTERNAL_CAMERA");
 
 static constexpr int32_t kVendorClientScore = resource_policy::PERCEPTIBLE_APP_ADJ;
 static constexpr int32_t kVendorClientState = ActivityManager::PROCESS_STATE_PERSISTENT_UI;
@@ -166,6 +170,7 @@
     mUidPolicy->registerSelf();
     mSensorPrivacyPolicy = new SensorPrivacyPolicy(this);
     mSensorPrivacyPolicy->registerSelf();
+    mInjectionStatusListener = new InjectionStatusListener(this);
     mAppOps.setCameraAudioRestriction(mAudioRestriction);
     sp<HidlCameraService> hcs = HidlCameraService::getInstance(this);
     if (hcs->registerAsService() != android::OK) {
@@ -243,6 +248,7 @@
     VendorTagDescriptor::clearGlobalVendorTagDescriptor();
     mUidPolicy->unregisterSelf();
     mSensorPrivacyPolicy->unregisterSelf();
+    mInjectionStatusListener->removeListener();
 }
 
 void CameraService::onNewProviderRegistered() {
@@ -2386,6 +2392,42 @@
     return Status::ok();
 }
 
+Status CameraService::injectCamera(
+        const String16& packageName, const String16& internalCamId,
+        const String16& externalCamId,
+        const sp<ICameraInjectionCallback>& callback,
+        /*out*/
+        sp<hardware::camera2::ICameraInjectionSession>* cameraInjectionSession) {
+    ATRACE_CALL();
+
+    if (!checkCallingPermission(sCameraInjectExternalCameraPermission)) {
+        const int pid = CameraThreadState::getCallingPid();
+        const int uid = CameraThreadState::getCallingUid();
+        ALOGE("Permission Denial: can't inject camera pid=%d, uid=%d", pid, uid);
+        return STATUS_ERROR(ERROR_PERMISSION_DENIED,
+                        "Permission Denial: no permission to inject camera");
+    }
+
+    ALOGV(
+        "%s: Package name = %s, Internal camera ID = %s, External camera ID = "
+        "%s",
+        __FUNCTION__, String8(packageName).string(),
+        String8(internalCamId).string(), String8(externalCamId).string());
+
+    binder::Status ret = binder::Status::ok();
+    // TODO: Implement the injection camera function.
+    // ret = internalInjectCamera(...);
+    // if(!ret.isOk()) {
+    //     mInjectionStatusListener->notifyInjectionError(...);
+    //     return ret;
+    // }
+
+    mInjectionStatusListener->addListener(callback);
+    *cameraInjectionSession = new CameraInjectionSession(this);
+
+    return ret;
+}
+
 void CameraService::removeByClient(const BasicClient* client) {
     Mutex::Autolock lock(mServiceLock);
     for (auto& i : mActiveClientManager.getAll()) {
@@ -3614,6 +3656,66 @@
 }
 
 // ----------------------------------------------------------------------------
+//                  InjectionStatusListener
+// ----------------------------------------------------------------------------
+
+void CameraService::InjectionStatusListener::addListener(
+        const sp<ICameraInjectionCallback>& callback) {
+    Mutex::Autolock lock(mListenerLock);
+    if (mCameraInjectionCallback) return;
+    status_t res = IInterface::asBinder(callback)->linkToDeath(this);
+    if (res == OK) {
+        mCameraInjectionCallback = callback;
+    }
+}
+
+void CameraService::InjectionStatusListener::removeListener() {
+    Mutex::Autolock lock(mListenerLock);
+    if (mCameraInjectionCallback == nullptr) {
+        ALOGW("InjectionStatusListener: mCameraInjectionCallback == nullptr");
+        return;
+    }
+    IInterface::asBinder(mCameraInjectionCallback)->unlinkToDeath(this);
+    mCameraInjectionCallback = nullptr;
+}
+
+void CameraService::InjectionStatusListener::notifyInjectionError(
+        int errorCode) {
+    Mutex::Autolock lock(mListenerLock);
+    if (mCameraInjectionCallback == nullptr) {
+        ALOGW("InjectionStatusListener: mCameraInjectionCallback == nullptr");
+        return;
+    }
+    mCameraInjectionCallback->onInjectionError(errorCode);
+}
+
+void CameraService::InjectionStatusListener::binderDied(
+        const wp<IBinder>& /*who*/) {
+    Mutex::Autolock lock(mListenerLock);
+    ALOGV("InjectionStatusListener: ICameraInjectionCallback has died");
+    auto parent = mParent.promote();
+    if (parent != nullptr) {
+        parent->stopInjectionImpl();
+    }
+}
+
+// ----------------------------------------------------------------------------
+//                  CameraInjectionSession
+// ----------------------------------------------------------------------------
+
+binder::Status CameraService::CameraInjectionSession::stopInjection() {
+    Mutex::Autolock lock(mInjectionSessionLock);
+    auto parent = mParent.promote();
+    if (parent == nullptr) {
+        ALOGE("CameraInjectionSession: Parent is gone");
+        return STATUS_ERROR(ICameraInjectionCallback::ERROR_INJECTION_SERVICE,
+                "Camera service encountered error");
+    }
+    parent->stopInjectionImpl();
+    return binder::Status::ok();
+}
+
+// ----------------------------------------------------------------------------
 
 static const int kDumpLockRetries = 50;
 static const int kDumpLockSleep = 60000;
@@ -4273,4 +4375,10 @@
     return mode;
 }
 
+void CameraService::stopInjectionImpl() {
+    mInjectionStatusListener->removeListener();
+
+    // TODO: Implement the stop injection function.
+}
+
 }; // namespace android
diff --git a/services/camera/libcameraservice/CameraService.h b/services/camera/libcameraservice/CameraService.h
index b436cec..10e1748 100644
--- a/services/camera/libcameraservice/CameraService.h
+++ b/services/camera/libcameraservice/CameraService.h
@@ -20,6 +20,8 @@
 #include <android/hardware/BnCameraService.h>
 #include <android/hardware/BnSensorPrivacyListener.h>
 #include <android/hardware/ICameraServiceListener.h>
+#include <android/hardware/camera2/BnCameraInjectionSession.h>
+#include <android/hardware/camera2/ICameraInjectionCallback.h>
 
 #include <cutils/multiuser.h>
 #include <utils/Vector.h>
@@ -180,6 +182,13 @@
             /*out*/
             bool *isSupported);
 
+    virtual binder::Status injectCamera(
+            const String16& packageName, const String16& internalCamId,
+            const String16& externalCamId,
+            const sp<hardware::camera2::ICameraInjectionCallback>& callback,
+            /*out*/
+            sp<hardware::camera2::ICameraInjectionSession>* cameraInjectionSession);
+
     // Extra permissions checks
     virtual status_t    onTransact(uint32_t code, const Parcel& data,
                                    Parcel* reply, uint32_t flags);
@@ -1147,6 +1156,46 @@
 
     // Current camera mute mode
     bool mOverrideCameraMuteMode = false;
+
+    /**
+     * A listener class that implements the IBinder::DeathRecipient interface
+     * for use to call back the error state injected by the external camera, and
+     * camera service can kill the injection when binder signals process death.
+     */
+    class InjectionStatusListener : public virtual IBinder::DeathRecipient {
+        public:
+            InjectionStatusListener(sp<CameraService> parent) : mParent(parent) {}
+
+            void addListener(const sp<hardware::camera2::ICameraInjectionCallback>& callback);
+            void removeListener();
+            void notifyInjectionError(int errorCode);
+
+            // IBinder::DeathRecipient implementation
+            virtual void binderDied(const wp<IBinder>& who);
+
+        private:
+            Mutex mListenerLock;
+            wp<CameraService> mParent;
+            sp<hardware::camera2::ICameraInjectionCallback> mCameraInjectionCallback;
+    };
+
+    sp<InjectionStatusListener> mInjectionStatusListener;
+
+    /**
+     * A class that implements the hardware::camera2::BnCameraInjectionSession interface
+     */
+    class CameraInjectionSession : public hardware::camera2::BnCameraInjectionSession {
+        public:
+            CameraInjectionSession(sp<CameraService> parent) : mParent(parent) {}
+            virtual ~CameraInjectionSession() {}
+            binder::Status stopInjection() override;
+
+        private:
+            Mutex mInjectionSessionLock;
+            wp<CameraService> mParent;
+    };
+
+    void stopInjectionImpl();
 };
 
 } // namespace android