libcamera: v4l2_subdevice: Store media entity

Store the media entity backing the V4L2Subdevice and add a deviceName()
method to retrieve the human readable name of the subdevice, which is
created using the name of the associated media entity.

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

2 files changed, 17 insertions, 8 deletions

diff --git a/src/libcamera/include/v4l2_subdevice.h b/src/libcamera/include/v4l2_subdevice.h
index 82fa6685..eac699a0 100644
--- a/src/libcamera/include/v4l2_subdevice.h
+++ b/src/libcamera/include/v4l2_subdevice.h
@@ -9,9 +9,10 @@
 
 #include <string>
 
+#include "media_object.h"
+
 namespace libcamera {
 
-class MediaEntity;
 struct Rectangle;
 
 struct V4L2SubdeviceFormat {
@@ -31,7 +32,8 @@ public:
 	bool isOpen() const;
 	void close();
 
-	std::string deviceNode() const { return deviceNode_; }
+	std::string deviceNode() const { return entity_->deviceNode(); }
+	std::string deviceName() const { return entity_->name(); }
 
 	int setCrop(unsigned int pad, Rectangle *rect);
 	int setCompose(unsigned int pad, Rectangle *rect);
@@ -43,7 +45,7 @@ private:
 	int setSelection(unsigned int pad, unsigned int target,
 			 Rectangle *rect);
 
-	std::string deviceNode_;
+	const MediaEntity *entity_;
 	int fd_;
 };
 
diff --git a/src/libcamera/v4l2_subdevice.cpp b/src/libcamera/v4l2_subdevice.cpp
index d47001d4..143f281a 100644
--- a/src/libcamera/v4l2_subdevice.cpp
+++ b/src/libcamera/v4l2_subdevice.cpp
@@ -88,7 +88,7 @@ LOG_DEFINE_CATEGORY(V4L2Subdev)
  * path
  */
 V4L2Subdevice::V4L2Subdevice(const MediaEntity *entity)
-	: deviceNode_(entity->deviceNode()), fd_(-1)
+	: entity_(entity), fd_(-1)
 {
 }
 
@@ -106,11 +106,11 @@ int V4L2Subdevice::open()
 		return -EBUSY;
 	}
 
-	ret = ::open(deviceNode_.c_str(), O_RDWR);
+	ret = ::open(deviceNode().c_str(), O_RDWR);
 	if (ret < 0) {
 		ret = -errno;
 		LOG(V4L2Subdev, Error)
-			<< "Failed to open V4L2 subdevice '" << deviceNode_
+			<< "Failed to open V4L2 subdevice '" << deviceNode()
 			<< "': " << strerror(-ret);
 		return ret;
 	}
@@ -148,6 +148,13 @@ void V4L2Subdevice::close()
  */
 
 /**
+ * \fn V4L2Subdevice::deviceName()
+ * \brief Retrieve the name of the media entity associated with the subdevice
+ *
+ * \return The name of the media entity the subdevice is associated to
+ */
+
+/**
  * \brief Set a crop rectangle on one of the V4L2 subdevice pads
  * \param[in] pad The 0-indexed pad number the rectangle is to be applied to
  * \param[inout] rect The rectangle describing crop target area
@@ -189,7 +196,7 @@ int V4L2Subdevice::getFormat(unsigned int pad, V4L2SubdeviceFormat *format)
 		ret = -errno;
 		LOG(V4L2Subdev, Error)
 			<< "Unable to get format on pad " << pad
-			<< " of " << deviceNode_ << ": " << strerror(-ret);
+			<< " of " << deviceNode() << ": " << strerror(-ret);
 		return ret;
 	}
 
@@ -255,7 +262,7 @@ int V4L2Subdevice::setSelection(unsigned int pad, unsigned int target,
 		ret = -errno;
 		LOG(V4L2Subdev, Error)
 			<< "Unable to set rectangle " << target << " on pad "
-			<< pad << " of " << deviceNode_ << ": "
+			<< pad << " of " << deviceNode() << ": "
 			<< strerror(-ret);
 		return ret;
 	}