android: hal: Add Camera3 HAL

Add libcamera Android Camera HALv3 implementation.

The initial camera HAL implementation supports the LIMITED hardware
level and uses statically defined metadata and camera characteristics.

Add a build option named 'android' and adjust the build system to
selectively compile the Android camera HAL and link it against the
required Android libraries.

Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>

1 files changed, 194 insertions, 0 deletions

diff --git a/src/android/camera_proxy.cpp b/src/android/camera_proxy.cpp
new file mode 100644
index 00000000..f0cacac8
--- /dev/null
+++ b/src/android/camera_proxy.cpp
@@ -0,0 +1,194 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2019, Google Inc.
+ *
+ * camera_proxy.cpp - Proxy to camera devices
+ */
+
+#include "camera_proxy.h"
+
+#include <system/camera_metadata.h>
+
+#include "log.h"
+#include "message.h"
+#include "utils.h"
+
+#include "camera_device.h"
+#include "thread_rpc.h"
+
+using namespace libcamera;
+
+LOG_DECLARE_CATEGORY(HAL);
+
+/*
+ * \class CameraProxy
+ *
+ * The CameraProxy wraps a CameraDevice and implements the camera3_device_t
+ * API, bridging calls received from the camera framework to the CameraDevice.
+ *
+ * Bridging operation calls between the framework and the CameraDevice is
+ * required as the two run in two different threads and certain operations,
+ * such as queueing a new capture request to the camera, shall be called in
+ * the thread that dispatches events. Other operations do not require any
+ * bridging and resolve to direct function calls on the CameraDevice instance
+ * instead.
+ */
+
+static int hal_dev_initialize(const struct camera3_device *dev,
+			      const camera3_callback_ops_t *callback_ops)
+{
+	if (!dev)
+		return -EINVAL;
+
+	CameraProxy *proxy = reinterpret_cast<CameraProxy *>(dev->priv);
+	proxy->initialize(callback_ops);
+
+	return 0;
+}
+
+static int hal_dev_configure_streams(const struct camera3_device *dev,
+				     camera3_stream_configuration_t *stream_list)
+{
+	if (!dev)
+		return -EINVAL;
+
+	CameraProxy *proxy = reinterpret_cast<CameraProxy *>(dev->priv);
+	return proxy->configureStreams(stream_list);
+}
+
+static const camera_metadata_t *
+hal_dev_construct_default_request_settings(const struct camera3_device *dev,
+					   int type)
+{
+	if (!dev)
+		return nullptr;
+
+	CameraProxy *proxy = reinterpret_cast<CameraProxy *>(dev->priv);
+	return proxy->constructDefaultRequestSettings(type);
+}
+
+static int hal_dev_process_capture_request(const struct camera3_device *dev,
+					   camera3_capture_request_t *request)
+{
+	if (!dev)
+		return -EINVAL;
+
+	CameraProxy *proxy = reinterpret_cast<CameraProxy *>(dev->priv);
+	return proxy->processCaptureRequest(request);
+}
+
+static void hal_dev_dump(const struct camera3_device *dev, int fd)
+{
+}
+
+static int hal_dev_flush(const struct camera3_device *dev)
+{
+	return 0;
+}
+
+static int hal_dev_close(hw_device_t *hw_device)
+{
+	if (!hw_device)
+		return -EINVAL;
+
+	camera3_device_t *dev = reinterpret_cast<camera3_device_t *>(hw_device);
+	CameraProxy *proxy = reinterpret_cast<CameraProxy *>(dev->priv);
+
+	proxy->close();
+
+	return 0;
+}
+
+static camera3_device_ops hal_dev_ops = {
+	.initialize = hal_dev_initialize,
+	.configure_streams = hal_dev_configure_streams,
+	.register_stream_buffers = nullptr,
+	.construct_default_request_settings = hal_dev_construct_default_request_settings,
+	.process_capture_request = hal_dev_process_capture_request,
+	.get_metadata_vendor_tag_ops = nullptr,
+	.dump = hal_dev_dump,
+	.flush = hal_dev_flush,
+	.reserved = { nullptr },
+};
+
+CameraProxy::CameraProxy(unsigned int id, std::shared_ptr<Camera> camera)
+	: id_(id)
+{
+	cameraDevice_ = new CameraDevice(id, camera);
+}
+
+CameraProxy::~CameraProxy()
+{
+	delete cameraDevice_;
+}
+
+int CameraProxy::open(const hw_module_t *hardwareModule)
+{
+	int ret = cameraDevice_->open();
+	if (ret)
+		return ret;
+
+	/* Initialize the hw_device_t in the instance camera3_module_t. */
+	camera3Device_.common.tag = HARDWARE_DEVICE_TAG;
+	camera3Device_.common.version = CAMERA_DEVICE_API_VERSION_3_3;
+	camera3Device_.common.module = (hw_module_t *)hardwareModule;
+	camera3Device_.common.close = hal_dev_close;
+
+	/*
+	 * The camera device operations. These actually implement
+	 * the Android Camera HALv3 interface.
+	 */
+	camera3Device_.ops = &hal_dev_ops;
+	camera3Device_.priv = this;
+
+	return 0;
+}
+
+void CameraProxy::close()
+{
+	ThreadRpc rpcRequest;
+	rpcRequest.tag = ThreadRpc::Close;
+
+	threadRpcCall(rpcRequest);
+}
+
+void CameraProxy::initialize(const camera3_callback_ops_t *callbacks)
+{
+	cameraDevice_->setCallbacks(callbacks);
+}
+
+const camera_metadata_t *CameraProxy::getStaticMetadata()
+{
+	return cameraDevice_->getStaticMetadata();
+}
+
+const camera_metadata_t *CameraProxy::constructDefaultRequestSettings(int type)
+{
+	return cameraDevice_->constructDefaultRequestSettings(type);
+}
+
+int CameraProxy::configureStreams(camera3_stream_configuration_t *stream_list)
+{
+	return cameraDevice_->configureStreams(stream_list);
+}
+
+int CameraProxy::processCaptureRequest(camera3_capture_request_t *request)
+{
+	ThreadRpc rpcRequest;
+	rpcRequest.tag = ThreadRpc::ProcessCaptureRequest;
+	rpcRequest.request = request;
+
+	threadRpcCall(rpcRequest);
+
+	return 0;
+}
+
+void CameraProxy::threadRpcCall(ThreadRpc &rpcRequest)
+{
+	std::unique_ptr<ThreadRpcMessage> message =
+				utils::make_unique<ThreadRpcMessage>();
+	message->rpc = &rpcRequest;
+
+	cameraDevice_->postMessage(std::move(message));
+	rpcRequest.waitDelivery();
+}