Initial HIDL vehicle HAL

Bug: b/31803520
Test: writing a test client in upcoming CLs

Change-Id: I050ab2d764f4550c5d0417c892d05d95472c9b7f
diff --git a/vehicle/2.0/IVehicleCallback.hal b/vehicle/2.0/IVehicleCallback.hal
new file mode 100644
index 0000000..1e9034f
--- /dev/null
+++ b/vehicle/2.0/IVehicleCallback.hal
@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2016 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.vehicle@2.0;
+
+interface IVehicleCallback {
+
+    /*
+     * Event callback happens whenever a variable that the API user has
+     * subscribed to needs to be reported. This may be based purely on
+     * threshold and frequency (a regular subscription, see subscribe call's
+     * arguments) or when the IVehicle#set method was called and the actual
+     * change needs to be reported.
+     *
+     * These callbacks are chunked.
+     *
+     * @param values that has been updated.
+     */
+    onPropertyEvent(vec<VehiclePropValue> propValues);
+
+    /*
+     * This method gets called if the client was susbscribed to a property using
+     * SubscribeFlags::SET_CALL flag and IVehicle#set(...) method was called.
+     *
+     * These events must be delivered to subscriber immediately without any
+     * batching.
+     *
+     * @param value Value that was set by a client.
+     */
+    onPropertySet(VehiclePropValue propValue);
+
+    /*
+     * Called by HAL server when error condition has occurred.
+     *
+     * @param errorCode - any value from StatusCode enum.
+     * @parm property - a property where error has happened. If this is
+     * a generic error, this value should be VehicleProperty::INVALID.
+     * @param operation Represent the operation where the error has happened.
+     */
+    onError(StatusCode errorCode,
+            VehicleProperty propId,
+            VehiclePropertyOperation operation);
+};