[libcamera-devel] [PATCH] libcamera: pipeline: simple: Add support for ST's DCMIPP

[Daniel Scally]

The STM32 contains a camera pipeline known as the DCMIPP (Digital
Camera-Memory Interface Pixel Processor) which receives data from a
parallel interface and dumps the post-processed data to memory. The
pipeline is capable of some processing in the form of downscaling
captured data through cropping or skipping the sensor's output.

The simple pipeline handler is quite capable of handling the DCMIPP
given its operation is handled entirely through configuring the pads
of a media graph, so add support for the driver to the pipeline's
supportedDevices array.

Signed-off-by: Daniel Scally <dan.scally at ideasonboard.com>
---
Support for the dcmipp has been tested on an stm32mp135f-dk with a gc2145
camera sensor. Note that the dcmipp driver **is not** in mainline at the moment,
and nor is the gc2145's driver. @Hugues, @Alain, is there a plan to move those
drivers upstream?

A few changes to ST's kernel were needed to fix some format propagation problems
and some missing controls for the GC2145 for this to work. Those can be found in
my tree linked below [1], along with some fixes to the CSI-2 to Parallel bridge
driver which _is_ upstream and which I posted to linux-media [2].

[1] https://github.com/djrscally/linux/tree/v5.15-stm32mp
[2] https://lore.kernel.org/linux-media/20230502103547.150918-1-dan.scally@ideasonboard.com/T/#t

 src/libcamera/pipeline/simple/simple.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/libcamera/pipeline/simple/simple.cpp b/src/libcamera/pipeline/simple/simple.cpp
index e1f8b989..01516bc3 100644
--- a/src/libcamera/pipeline/simple/simple.cpp
+++ b/src/libcamera/pipeline/simple/simple.cpp
@@ -194,6 +194,7 @@ static const SimplePipelineInfo supportedDevices[] = {
 	{ "mxc-isi", {} },
 	{ "qcom-camss", {} },
 	{ "sun6i-csi", {} },
+	{ "dcmipp", {} },
 };
 
 } /* namespace */
-- 
2.34.1