Initial Android Auto External View Systems drivers

Add support for EVS system camera and display drivers.
These build and run but still contain significant placeholder code and
TODO items.

Bug: 32095143
Test:  run against evs_test (submitted in future change set)
Change-Id: I9187e888f03248e5cd43293253dc76a71184c02d
diff --git a/evs/1.0/default/EvsCamera.cpp b/evs/1.0/default/EvsCamera.cpp
new file mode 100644
index 0000000..32d4ed7
--- /dev/null
+++ b/evs/1.0/default/EvsCamera.cpp
@@ -0,0 +1,305 @@
+/*
+ * 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.
+ */
+
+#define LOG_TAG "android.hardware.evs@1.0-service"
+
+#include "EvsCamera.h"
+
+#include <ui/GraphicBufferAllocator.h>
+#include <ui/GraphicBufferMapper.h>
+
+
+namespace android {
+namespace hardware {
+namespace evs {
+namespace V1_0 {
+namespace implementation {
+
+
+// These are the special camera names for which we'll initialize custom test data
+const char EvsCamera::kCameraName_Backup[]    = "backup";
+const char EvsCamera::kCameraName_RightTurn[] = "Right Turn";
+
+
+// TODO(b/31632518):  Need to get notification when our client dies so we can close the camera.
+// As it stands, if the client dies suddently, the buffer may be stranded.
+// As possible work around would be to give the client a HIDL object to exclusively hold
+// and use it's destructor to perform some work in the server side.
+
+EvsCamera::EvsCamera(const char *id) {
+    ALOGD("EvsCamera instantiated");
+
+    mDescription.cameraId = id;
+    mFrameBusy = false;
+    mStreamState = STOPPED;
+
+    // Set up dummy data for testing
+    if (mDescription.cameraId == kCameraName_Backup) {
+        mDescription.hints                  = UsageHint::USAGE_HINT_REVERSE;
+        mDescription.vendorFlags            = 0xFFFFFFFF;   // Arbitrary value
+        mDescription.defaultHorResolution   = 320;          // 1/2 NTSC/VGA
+        mDescription.defaultVerResolution   = 240;          // 1/2 NTSC/VGA
+    }
+    else if (mDescription.cameraId == kCameraName_RightTurn) {
+        // Nothing but the name and the usage hint
+        mDescription.hints                  = UsageHint::USAGE_HINT_RIGHT_TURN;
+    }
+    else {
+        // Leave empty for a minimalist camera description without even a hint
+    }
+}
+
+EvsCamera::~EvsCamera() {
+    ALOGD("EvsCamera being destroyed");
+    std::lock_guard<std::mutex> lock(mAccessLock);
+
+    // Make sure our output stream is cleaned up
+    // (It really should be already)
+    stopVideoStream();
+
+    // Drop the graphics buffer we've been using
+    if (mBuffer) {
+        // Drop the graphics buffer we've been using
+        GraphicBufferAllocator& alloc(GraphicBufferAllocator::get());
+        alloc.free(mBuffer);
+    }
+
+    ALOGD("EvsCamera destroyed");
+}
+
+
+// Methods from ::android::hardware::evs::V1_0::IEvsCamera follow.
+Return<void> EvsCamera::getId(getId_cb id_cb) {
+    ALOGD("getId");
+
+    id_cb(mDescription.cameraId);
+
+    return Void();
+}
+
+
+Return<EvsResult> EvsCamera::setMaxFramesInFlight(uint32_t bufferCount) {
+    ALOGD("setMaxFramesInFlight");
+    std::lock_guard<std::mutex> lock(mAccessLock);
+
+    // TODO:  Update our stored value
+
+    // TODO:  Adjust our buffer count right now if we can.  Otherwise, it'll adjust in doneWithFrame
+
+    // For now we support only one!
+    if (bufferCount != 1) {
+        return EvsResult::BUFFER_NOT_AVAILABLE;
+    }
+
+    return EvsResult::OK;
+}
+
+Return<EvsResult> EvsCamera::startVideoStream(const ::android::sp<IEvsCameraStream>& stream)  {
+    ALOGD("startVideoStream");
+    std::lock_guard<std::mutex> lock(mAccessLock);
+
+    // We only support a single stream at a time
+    if (mStreamState != STOPPED) {
+        ALOGE("ignoring startVideoStream call when a stream is already running.");
+        return EvsResult::STREAM_ALREADY_RUNNING;
+    }
+
+    // Record the user's callback for use when we have a frame ready
+    mStream = stream;
+
+    // Allocate a graphics buffer into which we'll put our test images
+    if (!mBuffer) {
+        mWidth  = (mDescription.defaultHorResolution) ? mDescription.defaultHorResolution : 640;
+        mHeight = (mDescription.defaultVerResolution) ? mDescription.defaultVerResolution : 480;
+        // TODO:  What about stride?  Assume no padding for now...
+        mStride = 4* mWidth;    // Special cased to assume 4 byte pixels with no padding for now
+
+        ALOGD("Allocating buffer for camera frame");
+        GraphicBufferAllocator &alloc(GraphicBufferAllocator::get());
+        status_t result = alloc.allocate(mWidth, mHeight,
+                                         HAL_PIXEL_FORMAT_RGBA_8888, 1, GRALLOC_USAGE_HW_TEXTURE,
+                                         &mBuffer, &mStride, 0, "EvsCamera");
+        if (result != NO_ERROR) {
+            ALOGE("Error %d allocating %d x %d graphics buffer", result, mWidth, mHeight);
+            return EvsResult::BUFFER_NOT_AVAILABLE;
+        }
+        if (!mBuffer) {
+            ALOGE("We didn't get a buffer handle back from the allocator");
+            return EvsResult::BUFFER_NOT_AVAILABLE;
+        }
+    }
+
+    // Start the frame generation thread
+    mStreamState = RUNNING;
+    mCaptureThread = std::thread([this](){GenerateFrames();});
+
+    return EvsResult::OK;
+}
+
+Return<EvsResult> EvsCamera::doneWithFrame(uint32_t frameId, const hidl_handle& bufferHandle)  {
+    ALOGD("doneWithFrame");
+    std::lock_guard<std::mutex> lock(mAccessLock);
+
+    if (!bufferHandle)
+    {
+        ALOGE("ignoring doneWithFrame called with invalid handle");
+        return EvsResult::INVALID_ARG;
+    }
+
+    // TODO:  Track which frames we've delivered and validate this is one of them
+
+    // Mark the frame buffer as available for a new frame
+    mFrameBusy = false;
+
+    // TODO:  If we currently have too many buffers, drop this one
+
+    return EvsResult::OK;
+}
+
+Return<void> EvsCamera::stopVideoStream()  {
+    ALOGD("stopVideoStream");
+
+    bool waitForJoin = false;
+    // Lock scope
+    {
+        std::lock_guard <std::mutex> lock(mAccessLock);
+
+        if (mStreamState == RUNNING) {
+            // Tell the GenerateFrames loop we want it to stop
+            mStreamState = STOPPING;
+
+            // Note that we asked the thread to stop and should wait for it do so
+            waitForJoin = true;
+        }
+    }
+
+    if (waitForJoin) {
+        // Block outside the mutex until the "stop" flag has been acknowledged
+        // NOTE:  We won't send any more frames, but the client might still get one already in flight
+        ALOGD("Waiting for stream thread to end...");
+        mCaptureThread.join();
+
+        // Lock scope
+        {
+            std::lock_guard <std::mutex> lock(mAccessLock);
+            mStreamState = STOPPED;
+        }
+    }
+
+    return Void();
+}
+
+Return<int32_t> EvsCamera::getExtendedInfo(uint32_t opaqueIdentifier)  {
+    ALOGD("getExtendedInfo");
+    std::lock_guard<std::mutex> lock(mAccessLock);
+
+    // For any single digit value, return the index itself as a test value
+    if (opaqueIdentifier <= 9) {
+        return opaqueIdentifier;
+    }
+
+    // Return zero by default as required by the spec
+    return 0;
+}
+
+Return<EvsResult> EvsCamera::setExtendedInfo(uint32_t /*opaqueIdentifier*/, int32_t /*opaqueValue*/)  {
+    ALOGD("setExtendedInfo");
+    std::lock_guard<std::mutex> lock(mAccessLock);
+
+    // We don't store any device specific information in this implementation
+    return EvsResult::INVALID_ARG;
+}
+
+
+void EvsCamera::GenerateFrames() {
+    ALOGD("Frame generate loop started");
+
+    uint32_t frameNumber;
+
+    while (true) {
+        bool timeForFrame = false;
+        // Lock scope
+        {
+            std::lock_guard<std::mutex> lock(mAccessLock);
+
+            // Tick the frame counter -- rollover is tolerated
+            frameNumber = mFrameId++;
+
+            if (mStreamState != RUNNING) {
+                // Break out of our main thread loop
+                break;
+            }
+
+            if (mFrameBusy) {
+                // Can't do anything right now -- skip this frame
+                ALOGW("Skipped a frame because client hasn't returned a buffer\n");
+            }
+            else {
+                // We're going to make the frame busy
+                mFrameBusy = true;
+                timeForFrame = true;
+            }
+        }
+
+        if (timeForFrame) {
+            // Lock our output buffer for writing
+            uint32_t *pixels = nullptr;
+            GraphicBufferMapper &mapper = GraphicBufferMapper::get();
+            mapper.lock(mBuffer,
+                        GRALLOC_USAGE_SW_WRITE_OFTEN,
+                        android::Rect(mWidth, mHeight),
+                        (void **) &pixels);
+
+            // If we failed to lock the pixel buffer, we're about to crash, but log it first
+            if (!pixels) {
+                ALOGE("Camera failed to gain access to image buffer for writing");
+            }
+
+            // Fill in the test pixels
+            for (unsigned row = 0; row < mHeight; row++) {
+                for (unsigned col = 0; col < mWidth; col++) {
+                    // Index into the row to set the pixel at this column
+                    // (We're making vertical gradient in the green channel, and
+                    // horitzontal gradient in the blue channel)
+                    pixels[col] = 0xFF0000FF | ((row & 0xFF) << 16) | ((col & 0xFF) << 8);
+                }
+                // Point to the next row
+                pixels = pixels + (mStride / sizeof(*pixels));
+            }
+
+            // Release our output buffer
+            mapper.unlock(mBuffer);
+
+            // Issue the (asynchronous) callback to the client
+            mStream->deliverFrame(frameNumber, mBuffer);
+            ALOGD("Delivered %p as frame %d", mBuffer, frameNumber);
+        }
+
+        // We arbitrarily choose to generate frames at 10 fps (1/10 * uSecPerSec)
+        usleep(100000);
+    }
+
+    // If we've been asked to stop, send one last NULL frame to signal the actual end of stream
+    mStream->deliverFrame(frameNumber, nullptr);
+
+    return;
+}
+
+} // namespace implementation
+} // namespace V1_0
+} // namespace evs
+} // namespace hardware
+} // namespace android