[libcamera-devel] [PATCH v3 1/8] libcamera: v4l2_subdevice: Store media entity

[Jacopo Mondi]

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.

Use the deviceName() in error messages where appropriate, as the entity
name is sometimes more informative than the device node path.

Signed-off-by: Jacopo Mondi <jacopo at jmondi.org>
---
 src/libcamera/include/v4l2_subdevice.h |  8 +++++---
 src/libcamera/v4l2_subdevice.cpp       | 17 ++++++++++++-----
 2 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/src/libcamera/include/v4l2_subdevice.h b/src/libcamera/include/v4l2_subdevice.h
index 82fa6685ab52..eac699a06109 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 b436f73cc75f..56ecf3851cb0 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;
 	}
@@ -147,6 +147,13 @@ void V4L2Subdevice::close()
  * \return The subdevice's device node system path
  */
 
+/**
+ * \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
@@ -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 " << deviceName() << ": " << 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 " << deviceName() << ": "
 			<< strerror(-ret);
 		return ret;
 	}
-- 
2.20.1