pipeline: vimc: Allocate mock IPA buffers

VIMC is a virtual test driver that doesn't have statistics or
parameters buffers that are typically passed from a pipeline
handler to its platform IPA. To increase the test coverage going
forward, we can at least mimick the typical interaction of how
a pipeline handler and IPA interact, and use it to increase the
test coverage.

Hence, create simple (single plane) dmabuf-backed FrameBuffers,
which can act as mock IPA buffers and can be memory mapped (mmap)
to VIMC IPA. To create these buffers, temporarily hijack the output
video node and configure it with a V4L2DeviceFormat. Buffers then
can be exported from the output video node using
V4L2VideoDevice::exportBuffers(). These buffers will be mimicked as
IPA buffers in subsequent commits.

Signed-off-by: Umang Jain <umang.jain@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>

1 files changed, 23 insertions, 0 deletions

diff --git a/src/libcamera/pipeline/vimc/vimc.cpp b/src/libcamera/pipeline/vimc/vimc.cpp
index 4c92729d..90e0d558 100644
--- a/src/libcamera/pipeline/vimc/vimc.cpp
+++ b/src/libcamera/pipeline/vimc/vimc.cpp
@@ -50,6 +50,7 @@ public:
 	}
 
 	int init();
+	int allocateMockIPABuffers();
 	void bufferReady(FrameBuffer *buffer);
 
 	MediaDevice *media_;
@@ -61,6 +62,7 @@ public:
 	Stream stream_;
 
 	std::unique_ptr<ipa::vimc::IPAProxyVimc> ipa_;
+	std::vector<std::unique_ptr<FrameBuffer>> mockIPABufs_;
 };
 
 class VimcCameraConfiguration : public CameraConfiguration
@@ -500,6 +502,12 @@ int VimcCameraData::init()
 	if (raw_->open())
 		return -ENODEV;
 
+	ret = allocateMockIPABuffers();
+	if (ret < 0) {
+		LOG(VIMC, Warning) << "Cannot allocate mock IPA buffers";
+		return ret;
+	}
+
 	/* Initialise the supported controls. */
 	const ControlInfoMap &controls = sensor_->controls();
 	ControlInfoMap::Map ctrls;
@@ -548,6 +556,21 @@ void VimcCameraData::bufferReady(FrameBuffer *buffer)
 	pipe_->completeRequest(request);
 }
 
+int VimcCameraData::allocateMockIPABuffers()
+{
+	constexpr unsigned int kBufCount = 2;
+
+	V4L2DeviceFormat format;
+	format.fourcc = video_->toV4L2PixelFormat(formats::BGR888);
+	format.size = Size (160, 120);
+
+	int ret = video_->setFormat(&format);
+	if (ret < 0)
+		return ret;
+
+	return video_->exportBuffers(kBufCount, &mockIPABufs_);
+}
+
 REGISTER_PIPELINE_HANDLER(PipelineHandlerVimc)
 
 } /* namespace libcamera */