V4L2 HALv3 initial check in

Decent outline of an initial HALv3. Still a lot to be filled in.
Adapted from the reference implementation in libhardware.

BUG: 29006356
TEST: Ran simple test program. Connects to the HAL and then
  fails because there are no cameras (expected behavior right now).

Change-Id: I11c7e00dca1bbb6ade6b5a0f55fedac3d2d01695
diff --git a/modules/camera/3_4/Stream.h b/modules/camera/3_4/Stream.h
new file mode 100644
index 0000000..2187f2b
--- /dev/null
+++ b/modules/camera/3_4/Stream.h
@@ -0,0 +1,85 @@
+/*
+ * 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.
+ */
+
+// Modified from hardware/libhardware/modules/camera/Stream.h
+
+#ifndef STREAM_H_
+#define STREAM_H_
+
+#include <hardware/camera3.h>
+#include <hardware/gralloc.h>
+#include <system/graphics.h>
+#include <utils/Mutex.h>
+
+namespace default_camera_hal {
+// Stream represents a single input or output stream for a camera device.
+class Stream {
+    public:
+        Stream(int id, camera3_stream_t *s);
+        ~Stream();
+
+        // validate that astream's parameters match this stream's parameters
+        bool isValidReuseStream(int id, camera3_stream_t *s);
+
+        // Register buffers with hardware
+        int registerBuffers(const camera3_stream_buffer_set_t *buf_set);
+
+        void setUsage(uint32_t usage);
+        void setMaxBuffers(uint32_t max_buffers);
+
+        int getType();
+        bool isInputType();
+        bool isOutputType();
+        bool isRegistered();
+        const char* typeToString(int type);
+        const char* formatToString(int format);
+        void dump(int fd);
+
+        // This stream is being reused. Used in stream configuration passes
+        bool mReuse;
+
+    private:
+        // Clean up buffer state. must be called with mLock held.
+        void unregisterBuffers_L();
+
+        // The camera device id this stream belongs to
+        const int mId;
+        // Handle to framework's stream, used as a cookie for buffers
+        camera3_stream_t *mStream;
+        // Stream type: CAMERA3_STREAM_* (see <hardware/camera3.h>)
+        const int mType;
+        // Width in pixels of the buffers in this stream
+        const uint32_t mWidth;
+        // Height in pixels of the buffers in this stream
+        const uint32_t mHeight;
+        // Gralloc format: HAL_PIXEL_FORMAT_* (see <system/graphics.h>)
+        const int mFormat;
+        // Gralloc usage mask : GRALLOC_USAGE_* (see <hardware/gralloc.h>)
+        uint32_t mUsage;
+        // Max simultaneous in-flight buffers for this stream
+        uint32_t mMaxBuffers;
+        // Buffers have been registered for this stream and are ready
+        bool mRegistered;
+        // Array of handles to buffers currently in use by the stream
+        buffer_handle_t **mBuffers;
+        // Number of buffers in mBuffers
+        unsigned int mNumBuffers;
+        // Lock protecting the Stream object for modifications
+        android::Mutex mLock;
+};
+} // namespace default_camera_hal
+
+#endif // STREAM_H_