usbcamera: initial implementation of default usb camera HAL

* Basic skeleton of usb camera hal implementation
* Vendor tag is not supported yet
* Further usb camera hal implementation can be filled into UsbCamera.cpp
* Hot plug thread need to be implemented

Change-Id: Ida63b6d640e32192f5b60a280d9d5106d80e523f
diff --git a/modules/usbcamera/UsbCamera.h b/modules/usbcamera/UsbCamera.h
new file mode 100644
index 0000000..fe52ade
--- /dev/null
+++ b/modules/usbcamera/UsbCamera.h
@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) 2015 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.
+ */
+
+#ifndef EXAMPLE_CAMERA_H_
+#define EXAMPLE_CAMERA_H_
+
+#include <system/camera_metadata.h>
+#include "Camera.h"
+
+namespace usb_camera_hal {
+/**
+ * UsbCamera is an example for a specific camera device. The Camera instance contains
+ * a specific camera device (e.g. UsbCamera) holds all specific metadata and logic about
+ * that device.
+ */
+class UsbCamera : public Camera {
+    public:
+        UsbCamera(int id);
+        ~UsbCamera();
+
+    private:
+        // Initialize static camera characteristics for individual device
+        int initStaticInfo();
+        int openDevice();
+        // Initialize whole device (templates/etc) when opened
+        int initDevice();
+        int flushDevice();
+        int closeDevice();
+        int processCaptureBuffer(const camera3_stream_buffer_t *in, camera3_stream_buffer_t *out);
+        // Initialize each template metadata controls
+        int initPreviewTemplate(Metadata m);
+        int initStillTemplate(Metadata m);
+        int initRecordTemplate(Metadata m);
+        int initSnapshotTemplate(Metadata m);
+        int initZslTemplate(Metadata m);
+        int initManualTemplate(Metadata m);
+        // Verify settings are valid for a capture with this device
+        bool isValidCaptureSettings(const camera_metadata_t* settings);
+};
+} // namespace usb_camera_hal
+
+#endif // CAMERA_H_