libcamera: pipeline: Add FrameBuffer handlers

Extend the pipeline handlers to support the FrameBuffer API with three
new methods to handle allocation, importing and freeing of buffers. The
new methods will replace allocateBuffers() and freeBuffers().

The FrameBuffer API will use the methods on a stream level and either
allocate or import buffers for each active stream controlled from the
Camera class and an upcoming FrameBufferAllocator helper. With this new
API the implementation in pipeline handlers can be made simpler as all
streams don't need to be handled in allocateBuffers().

Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

1 files changed, 32 insertions, 0 deletions

diff --git a/src/libcamera/pipeline/ipu3/ipu3.cpp b/src/libcamera/pipeline/ipu3/ipu3.cpp
index 7c4539d4..b73f0f07 100644
--- a/src/libcamera/pipeline/ipu3/ipu3.cpp
+++ b/src/libcamera/pipeline/ipu3/ipu3.cpp
@@ -210,6 +210,11 @@ public:
 		const StreamRoles &roles) override;
 	int configure(Camera *camera, CameraConfiguration *config) override;
 
+	int exportFrameBuffers(Camera *camera, Stream *stream,
+			       std::vector<std::unique_ptr<FrameBuffer>> *buffers) override;
+	int importFrameBuffers(Camera *camera, Stream *stream) override;
+	void freeFrameBuffers(Camera *camera, Stream *stream) override;
+
 	int allocateBuffers(Camera *camera,
 			    const std::set<Stream *> &streams) override;
 	int freeBuffers(Camera *camera,
@@ -616,6 +621,33 @@ int PipelineHandlerIPU3::configure(Camera *camera, CameraConfiguration *c)
 	return 0;
 }
 
+int PipelineHandlerIPU3::exportFrameBuffers(Camera *camera, Stream *stream,
+					    std::vector<std::unique_ptr<FrameBuffer>> *buffers)
+{
+	IPU3Stream *ipu3stream = static_cast<IPU3Stream *>(stream);
+	V4L2VideoDevice *video = ipu3stream->device_->dev;
+	unsigned int count = stream->configuration().bufferCount;
+
+	return video->exportBuffers(count, buffers);
+}
+
+int PipelineHandlerIPU3::importFrameBuffers(Camera *camera, Stream *stream)
+{
+	IPU3Stream *ipu3stream = static_cast<IPU3Stream *>(stream);
+	V4L2VideoDevice *video = ipu3stream->device_->dev;
+	unsigned int count = stream->configuration().bufferCount;
+
+	return video->importBuffers(count);
+}
+
+void PipelineHandlerIPU3::freeFrameBuffers(Camera *camera, Stream *stream)
+{
+	IPU3Stream *ipu3stream = static_cast<IPU3Stream *>(stream);
+	V4L2VideoDevice *video = ipu3stream->device_->dev;
+
+	video->releaseBuffers();
+}
+
 /**
  * \todo Clarify if 'viewfinder' and 'stat' nodes have to be set up and
  * started even if not in use. As of now, if not properly configured and