libcamera: converter: Utilise shared MediaDevice pointers

With the upcoming addition of V4L2 requests support, the converters need
to keep a handle to the corresponding media device.

Prepare for that by changing the constructor parameter from a raw
pointer to a shared pointer.

Signed-off-by: Stefan Klug <stefan.klug@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Isaac Scott <isaac.scott@ideasonboard.com>

include/libcamera/internal/converter.h

@@ -46,7 +46,7 @@ public:
 		Up,
 	};
 
-	Converter(MediaDevice *media, Features features = Feature::None);
+	Converter(std::shared_ptr<MediaDevice> media, Features features = Feature::None);
 	virtual ~Converter();
 
 	virtual int loadConfiguration(const std::string &filename) = 0;
@@ -107,7 +107,7 @@ public:
 
 	const std::vector<std::string> &compatibles() const { return compatibles_; }
 
-	static std::unique_ptr<Converter> create(MediaDevice *media);
+	static std::unique_ptr<Converter> create(std::shared_ptr<MediaDevice> media);
 	static std::vector<ConverterFactoryBase *> &factories();
 	static std::vector<std::string> names();
 
@@ -116,7 +116,8 @@ private:
 
 	static void registerType(ConverterFactoryBase *factory);
 
-	virtual std::unique_ptr<Converter> createInstance(MediaDevice *media) const = 0;
+	virtual std::unique_ptr<Converter>
+	createInstance(std::shared_ptr<MediaDevice> media) const = 0;
 
 	std::string name_;
 	std::vector<std::string> compatibles_;
@@ -131,7 +132,7 @@ public:
 	{
 	}
 
-	std::unique_ptr<Converter> createInstance(MediaDevice *media) const override
+	std::unique_ptr<Converter> createInstance(std::shared_ptr<MediaDevice> media) const override
 	{
 		return std::make_unique<_Converter>(media);
 	}

include/libcamera/internal/converter/converter_v4l2_m2m.h

@@ -36,7 +36,7 @@ class V4L2M2MDevice;
 class V4L2M2MConverter : public Converter
 {
 public:
-	V4L2M2MConverter(MediaDevice *media);
+	V4L2M2MConverter(std::shared_ptr<MediaDevice> media);
 
 	int loadConfiguration([[maybe_unused]] const std::string &filename) override { return 0; }
 	bool isValid() const override { return m2m_ != nullptr; }

src/libcamera/converter.cpp

@@ -8,6 +8,7 @@
 #include "libcamera/internal/converter.h"
 
 #include <algorithm>
+#include <memory>
 
 #include <libcamera/base/log.h>
 
@@ -68,7 +69,7 @@ LOG_DEFINE_CATEGORY(Converter)
  * This searches for the entity implementing the data streaming function in the
  * media graph entities and use its device node as the converter device node.
  */
-Converter::Converter(MediaDevice *media, Features features)
+Converter::Converter(std::shared_ptr<MediaDevice> media, Features features)
 {
 	const std::vector<MediaEntity *> &entities = media->entities();
 	auto it = std::find_if(entities.begin(), entities.end(),
@@ -332,7 +333,7 @@ ConverterFactoryBase::ConverterFactoryBase(const std::string name, std::initiali
  * \return A new instance of the converter subclass corresponding to the media
  * device, or null if the media device driver name doesn't match anything
  */
-std::unique_ptr<Converter> ConverterFactoryBase::create(MediaDevice *media)
+std::unique_ptr<Converter> ConverterFactoryBase::create(std::shared_ptr<MediaDevice> media)
 {
 	const std::vector<ConverterFactoryBase *> &factories =
 		ConverterFactoryBase::factories();

src/libcamera/converter/converter_v4l2_m2m.cpp

@@ -10,6 +10,7 @@
 
 #include <algorithm>
 #include <limits.h>
+#include <memory>
 #include <set>
 
 #include <libcamera/base/log.h>
@@ -261,8 +262,7 @@ void V4L2M2MConverter::V4L2M2MStream::captureBufferReady(FrameBuffer *buffer)
  * \brief Construct a V4L2M2MConverter instance
  * \param[in] media The media device implementing the converter
  */
-
-V4L2M2MConverter::V4L2M2MConverter(MediaDevice *media)
+V4L2M2MConverter::V4L2M2MConverter(std::shared_ptr<MediaDevice> media)
 	: Converter(media)
 {
 	if (deviceNode().empty())

src/libcamera/pipeline/rkisp1/rkisp1.cpp

@@ -1445,7 +1445,7 @@ bool PipelineHandlerRkISP1::match(DeviceEnumerator *enumerator)
 
 	std::shared_ptr<MediaDevice> dwpMediaDevice = enumerator->search(dwp);
 	if (dwpMediaDevice) {
-		dewarper_ = std::make_unique<V4L2M2MConverter>(dwpMediaDevice.get());
+		dewarper_ = std::make_unique<V4L2M2MConverter>(dwpMediaDevice);
 		if (dewarper_->isValid()) {
 			dewarper_->outputBufferReady.connect(
 				this, &PipelineHandlerRkISP1::dewarpBufferReady);

src/libcamera/pipeline/simple/simple.cpp

@@ -415,7 +415,7 @@ public:
 
 	V4L2VideoDevice *video(const MediaEntity *entity);
 	V4L2Subdevice *subdev(const MediaEntity *entity);
-	MediaDevice *converter() { return converter_.get(); }
+	std::shared_ptr<MediaDevice> converter() { return converter_; }
 	bool swIspEnabled() const { return swIspEnabled_; }
 
 protected:
@@ -588,7 +588,7 @@ int SimpleCameraData::init()
 	int ret;
 
 	/* Open the converter, if any. */
-	MediaDevice *converter = pipe->converter();
+	std::shared_ptr<MediaDevice> converter = pipe->converter();
 	if (converter) {
 		converter_ = ConverterFactoryBase::create(converter);
 		if (!converter_) {