Move EVS HAL under automotive folder

Test:  Build locally
Change-Id: I76aa7eb52497169d0edcb6d756e0a7ca31bb0b46
diff --git a/automotive/evs/1.0/default/EvsDisplay.cpp b/automotive/evs/1.0/default/EvsDisplay.cpp
new file mode 100644
index 0000000..a1a76d0
--- /dev/null
+++ b/automotive/evs/1.0/default/EvsDisplay.cpp
@@ -0,0 +1,308 @@
+/*
+ * 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.automotive.evs@1.0-service"
+
+#include "EvsDisplay.h"
+
+#include <ui/GraphicBufferAllocator.h>
+#include <ui/GraphicBufferMapper.h>
+
+
+namespace android {
+namespace hardware {
+namespace automotive {
+namespace evs {
+namespace V1_0 {
+namespace implementation {
+
+
+// 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.
+
+
+EvsDisplay::EvsDisplay() {
+    ALOGD("EvsDisplay instantiated");
+
+    // Set up our self description
+    // NOTE:  These are arbitrary values chosen for testing
+    mInfo.displayId             = "Mock Display";
+    mInfo.vendorFlags           = 3870;
+    mInfo.defaultHorResolution  = 320;
+    mInfo.defaultVerResolution  = 240;
+}
+
+
+EvsDisplay::~EvsDisplay() {
+    ALOGD("EvsDisplay being destroyed");
+    std::lock_guard<std::mutex> lock(mAccessLock);
+
+    // Report if we're going away while a buffer is outstanding
+    if (mFrameBusy) {
+        ALOGE("EvsDisplay going down while client is holding a buffer");
+    }
+
+    // Make sure we release our frame buffer
+    if (mBuffer.memHandle) {
+        // Drop the graphics buffer we've been using
+        GraphicBufferAllocator& alloc(GraphicBufferAllocator::get());
+        alloc.free(mBuffer.memHandle);
+        mBuffer.memHandle = nullptr;
+    }
+    ALOGD("EvsDisplay destroyed");
+}
+
+
+/**
+ * Returns basic information about the EVS display provided by the system.
+ * See the description of the DisplayDesc structure below for details.
+ */
+Return<void> EvsDisplay::getDisplayInfo(getDisplayInfo_cb _hidl_cb)  {
+    ALOGD("getDisplayInfo");
+
+    // Send back our self description
+    _hidl_cb(mInfo);
+    return Void();
+}
+
+
+/**
+ * Clients may set the display state to express their desired state.
+ * The HAL implementation must gracefully accept a request for any state
+ * while in any other state, although the response may be to ignore the request.
+ * The display is defined to start in the NOT_VISIBLE state upon initialization.
+ * The client is then expected to request the VISIBLE_ON_NEXT_FRAME state, and
+ * then begin providing video.  When the display is no longer required, the client
+ * is expected to request the NOT_VISIBLE state after passing the last video frame.
+ */
+Return<EvsResult> EvsDisplay::setDisplayState(DisplayState state) {
+    ALOGD("setDisplayState");
+    std::lock_guard<std::mutex> lock(mAccessLock);
+
+    // Ensure we recognize the requested state so we don't go off the rails
+    if (state < DisplayState::NUM_STATES) {
+        // Record the requested state
+        mRequestedState = state;
+        return EvsResult::OK;
+    }
+    else {
+        // Turn off the display if asked for an unrecognized state
+        mRequestedState = DisplayState::NOT_VISIBLE;
+        return EvsResult::INVALID_ARG;
+    }
+}
+
+
+/**
+ * The HAL implementation should report the actual current state, which might
+ * transiently differ from the most recently requested state.  Note, however, that
+ * the logic responsible for changing display states should generally live above
+ * the device layer, making it undesirable for the HAL implementation to
+ * spontaneously change display states.
+ */
+Return<DisplayState> EvsDisplay::getDisplayState()  {
+    ALOGD("getDisplayState");
+    std::lock_guard<std::mutex> lock(mAccessLock);
+
+    // At the moment, we treat the requested state as immediately active
+    DisplayState currentState = mRequestedState;
+
+    return currentState;
+}
+
+
+/**
+ * This call returns a handle to a frame buffer associated with the display.
+ * This buffer may be locked and written to by software and/or GL.  This buffer
+ * must be returned via a call to returnTargetBufferForDisplay() even if the
+ * display is no longer visible.
+ */
+// TODO: We need to know if/when our client dies so we can get the buffer back! (blocked b/31632518)
+Return<void> EvsDisplay::getTargetBuffer(getTargetBuffer_cb _hidl_cb)  {
+    ALOGD("getTargetBuffer");
+    std::lock_guard<std::mutex> lock(mAccessLock);
+
+    // If we don't already have a buffer, allocate one now
+    if (!mBuffer.memHandle) {
+        // Assemble the buffer description we'll use for our render target
+        mBuffer.width       = mInfo.defaultHorResolution;
+        mBuffer.height      = mInfo.defaultVerResolution;
+        mBuffer.format      = HAL_PIXEL_FORMAT_RGBA_8888;
+        mBuffer.usage       = GRALLOC_USAGE_HW_RENDER | GRALLOC_USAGE_HW_COMPOSER;
+        mBuffer.bufferId    = 0x3870;  // Arbitrary magic number for self recognition
+
+        buffer_handle_t handle = nullptr;
+        GraphicBufferAllocator& alloc(GraphicBufferAllocator::get());
+        status_t result = alloc.allocate(mBuffer.width, mBuffer.height,
+                                         mBuffer.format, 1, mBuffer.usage,
+                                         mBuffer.usage, &handle,
+                                         &mBuffer.stride,
+                                         0, "EvsDisplay");
+        if (result != NO_ERROR) {
+            ALOGE("Error %d allocating %d x %d graphics buffer",
+                  result, mBuffer.width, mBuffer.height);
+            BufferDesc nullBuff = {};
+            _hidl_cb(nullBuff);
+            return Void();
+        }
+        if (!handle) {
+            ALOGE("We didn't get a buffer handle back from the allocator");
+            BufferDesc nullBuff = {};
+            _hidl_cb(nullBuff);
+            return Void();
+        }
+
+        mBuffer.memHandle = handle;
+        mFrameBusy = false;
+        ALOGD("Allocated new buffer %p with stride %u",
+              mBuffer.memHandle.getNativeHandle(), mBuffer.stride);
+    }
+
+    // Do we have a frame available?
+    if (mFrameBusy) {
+        // This means either we have a 2nd client trying to compete for buffers
+        // (an unsupported mode of operation) or else the client hasn't returned
+        // a previously issued buffer yet (they're behaving badly).
+        // NOTE:  We have to make the callback even if we have nothing to provide
+        ALOGE("getTargetBuffer called while no buffers available.");
+        BufferDesc nullBuff = {};
+        _hidl_cb(nullBuff);
+        return Void();
+    } else {
+        // Mark our buffer as busy
+        mFrameBusy = true;
+
+        // Send the buffer to the client
+        ALOGD("Providing display buffer handle %p as id %d",
+              mBuffer.memHandle.getNativeHandle(), mBuffer.bufferId);
+        _hidl_cb(mBuffer);
+        return Void();
+    }
+}
+
+
+/**
+ * This call tells the display that the buffer is ready for display.
+ * The buffer is no longer valid for use by the client after this call.
+ */
+Return<EvsResult> EvsDisplay::returnTargetBufferForDisplay(const BufferDesc& buffer)  {
+    ALOGD("returnTargetBufferForDisplay %p", buffer.memHandle.getNativeHandle());
+    std::lock_guard<std::mutex> lock(mAccessLock);
+
+    // Nobody should call us with a null handle
+    if (!buffer.memHandle.getNativeHandle()) {
+        ALOGE ("returnTargetBufferForDisplay called without a valid buffer handle.\n");
+        return EvsResult::INVALID_ARG;
+    }
+    if (buffer.bufferId != mBuffer.bufferId) {
+        ALOGE ("Got an unrecognized frame returned.\n");
+        return EvsResult::INVALID_ARG;
+    }
+    if (!mFrameBusy) {
+        ALOGE ("A frame was returned with no outstanding frames.\n");
+        return EvsResult::BUFFER_NOT_AVAILABLE;
+    }
+
+    mFrameBusy = false;
+
+    // If we were waiting for a new frame, this is it!
+    if (mRequestedState == DisplayState::VISIBLE_ON_NEXT_FRAME) {
+        mRequestedState = DisplayState::VISIBLE;
+    }
+
+    // Validate we're in an expected state
+    if (mRequestedState != DisplayState::VISIBLE) {
+        // We shouldn't get frames back when we're not visible.
+        ALOGE ("Got an unexpected frame returned while not visible - ignoring.\n");
+    } else {
+        // This is where the buffer would be made visible.
+        // For now we simply validate it has the data we expect in it by reading it back
+
+        // Lock our display buffer for reading
+        uint32_t* pixels = nullptr;
+        GraphicBufferMapper &mapper = GraphicBufferMapper::get();
+        mapper.lock(mBuffer.memHandle,
+                    GRALLOC_USAGE_SW_READ_OFTEN | GRALLOC_USAGE_SW_WRITE_NEVER,
+                    android::Rect(mBuffer.width, mBuffer.height),
+                    (void **)&pixels);
+
+        // If we failed to lock the pixel buffer, we're about to crash, but log it first
+        if (!pixels) {
+            ALOGE("Display failed to gain access to image buffer for reading");
+        }
+
+        // Check the test pixels
+        bool frameLooksGood = true;
+        for (unsigned row = 0; row < mInfo.defaultVerResolution; row++) {
+            for (unsigned col = 0; col < mInfo.defaultHorResolution; col++) {
+                // Index into the row to check the pixel at this column.
+                // We expect 0xFF in the LSB channel, a vertical gradient in the
+                // second channel, a horitzontal gradient in the third channel, and
+                // 0xFF in the MSB.
+                // The exception is the very first 32 bits which is used for the
+                // time varying frame signature to avoid getting fooled by a static image.
+                uint32_t expectedPixel = 0xFF0000FF           | // MSB and LSB
+                                         ((row & 0xFF) <<  8) | // vertical gradient
+                                         ((col & 0xFF) << 16);  // horizontal gradient
+                if ((row | col) == 0) {
+                    // we'll check the "uniqueness" of the frame signature below
+                    continue;
+                }
+                // Walk across this row (we'll step rows below)
+                uint32_t receivedPixel = pixels[col];
+                if (receivedPixel != expectedPixel) {
+                    ALOGE("Pixel check mismatch in frame buffer");
+                    frameLooksGood = false;
+                    break;
+                }
+            }
+
+            if (!frameLooksGood) {
+                break;
+            }
+
+            // Point to the next row (NOTE:  gralloc reports stride in units of pixels)
+            pixels = pixels + mBuffer.stride;
+        }
+
+        // Ensure we don't see the same buffer twice without it being rewritten
+        static uint32_t prevSignature = ~0;
+        uint32_t signature = pixels[0] & 0xFF;
+        if (prevSignature == signature) {
+            frameLooksGood = false;
+            ALOGE("Duplicate, likely stale frame buffer detected");
+        }
+
+
+        // Release our output buffer
+        mapper.unlock(mBuffer.memHandle);
+
+        if (!frameLooksGood) {
+            return EvsResult::UNDERLYING_SERVICE_ERROR;
+        }
+    }
+
+    return EvsResult::OK;
+}
+
+} // namespace implementation
+} // namespace V1_0
+} // namespace evs
+} // namespace automotive
+} // namespace hardware
+} // namespace android