libcamera: Add debug printouts

Add a few debug printouts that help follow the library intialization
process: what pipeline handlers are registered, what media devices are
created, and which pipeline manager gets matches with the current
system.

The resulting output is the following, on IPU3 devices:
DBG pipeline_handler.cpp:119 Pipeline handler: "PipeHandlerVimc" registered
DBG pipeline_handler.cpp:119 Pipeline handler: "PipelineHandlerIPU3" registered
DBG device_enumerator.cpp:214 New media device: ipu3-imgu created from: /dev/media0
DBG device_enumerator.cpp:214 New media device: ipu3-cio2 created from: /dev/media1
DBG device_enumerator.cpp:255 Succesfull match for media device: ipu3-cio2
DBG device_enumerator.cpp:255 Succesfull match for media device: ipu3-imgu
DBG pipeline_handler.cpp:150 Pipeline handler: "PipelineHandlerIPU3" matched

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>

1 files changed, 4 insertions, 1 deletions

diff --git a/src/libcamera/pipeline_handler.cpp b/src/libcamera/pipeline_handler.cpp
index ee769487..b5a85749 100644
--- a/src/libcamera/pipeline_handler.cpp
+++ b/src/libcamera/pipeline_handler.cpp
@@ -116,6 +116,7 @@ void PipelineHandlerFactory::registerType(const std::string &name,
 		return;
 	}
 
+	LOG(Debug) << "Registered pipeline handler: \"" << name << "\"";
 	factories[name] = factory;
 }
 
@@ -145,8 +146,10 @@ PipelineHandler *PipelineHandlerFactory::create(const std::string &name,
 
 	PipelineHandler *pipe = it->second->create();
 
-	if (pipe->match(enumerator))
+	if (pipe->match(enumerator)) {
+		LOG(Debug) << "Pipeline handler \"" << name << "\" matched";
 		return pipe;
+	}
 
 	delete pipe;
 	return nullptr;