ipa: vimc: Send and retrieve FrameBuffers from IPA

Plumb through VIMC mojo interface to enable buffers passing.
VIMC does not have parameters or statistics buffers but we can
mimick the typical case of passing IPA buffers from pipeline
handler to IPA using mock buffers. The mock IPA buffers are
FrameBuffers which are dmabuf backed (in other words, mmap()able
through MappedFramebuffer inside the IPA).

This commits shows:
- Passing the parameter buffer from the pipeline handler to
  the IPA through functions defined in mojom interface.
- Passing request controls ControlList to the IPA.

Any tests using VIMC will now loop in the IPA paths. Any tests running
in isolated mode will help us to test IPA IPC code paths especially
around (de)serialization of data passing from pipeline handlers to the
IPA. Future IPA interface tests can simply extend the vimc mojom
interface to achieve/test a specific use case as required.

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

1 files changed, 10 insertions, 1 deletions

diff --git a/include/libcamera/ipa/vimc.mojom b/include/libcamera/ipa/vimc.mojom
index 8cb240d3..e3b14e38 100644
--- a/include/libcamera/ipa/vimc.mojom
+++ b/include/libcamera/ipa/vimc.mojom
@@ -29,8 +29,17 @@ interface IPAVimcInterface {
 
 	mapBuffers(array<libcamera.IPABuffer> buffers);
 	unmapBuffers(array<uint32> ids);
+
+	/*
+	 * The vimc driver doesn't use parameters buffers. To maximize coverage
+	 * of unit tests that rely on the VIMC pipeline handler, we still define
+	 * interface functions that mimick how other pipeline handlers typically
+	 * handle parameters at runtime.
+	 */
+	[async] fillParams(uint32 frame, uint32 bufferId);
+	[async] processControls(uint32 frame, libcamera.ControlList controls);
 };
 
 interface IPAVimcEventInterface {
-	dummyEvent(uint32 val);
+	paramsFilled(uint32 bufferId);
 };