[libcamera-devel] [PATCH v5 07/19] libcamera: v4l2_subdevice: Create device from entity name

[Jacopo Mondi]

Add a static method to V4L2Subdevice class to create a V4L2Subdevice
instance from a media entity name.

Signed-off-by: Jacopo Mondi <jacopo at jmondi.org>
---
 src/libcamera/include/v4l2_subdevice.h |  5 +++++
 src/libcamera/v4l2_subdevice.cpp       | 22 ++++++++++++++++++++++
 2 files changed, 27 insertions(+)

diff --git a/src/libcamera/include/v4l2_subdevice.h b/src/libcamera/include/v4l2_subdevice.h
index f42cccabda94..0067109931d1 100644
--- a/src/libcamera/include/v4l2_subdevice.h
+++ b/src/libcamera/include/v4l2_subdevice.h
@@ -18,6 +18,8 @@
 
 namespace libcamera {
 
+class MediaDevice;
+
 struct V4L2SubdeviceFormat {
 	uint32_t mbus_code;
 	uint32_t width;
@@ -29,6 +31,9 @@ struct V4L2SubdeviceFormat {
 class V4L2Subdevice : protected Loggable
 {
 public:
+	static V4L2Subdevice *fromEntityName(const MediaDevice *media,
+					     const std::string &name);
+
 	explicit V4L2Subdevice(const MediaEntity *entity);
 	V4L2Subdevice(const V4L2Subdevice &) = delete;
 	V4L2Subdevice &operator=(const V4L2Subdevice &) = delete;
diff --git a/src/libcamera/v4l2_subdevice.cpp b/src/libcamera/v4l2_subdevice.cpp
index 10925f9fe497..e28857c9aeb1 100644
--- a/src/libcamera/v4l2_subdevice.cpp
+++ b/src/libcamera/v4l2_subdevice.cpp
@@ -16,6 +16,7 @@
 
 #include "geometry.h"
 #include "log.h"
+#include "media_device.h"
 #include "media_object.h"
 #include "v4l2_subdevice.h"
 
@@ -101,6 +102,27 @@ const std::string V4L2SubdeviceFormat::toString() const
  * any device left open will be closed, and any resources released.
  */
 
+/**
+ * \brief Create a new video subdevice instance from entity with \a name in
+ * media device \a media
+ * \param[in] media The media device where the entity is registered
+ * \param[in] name The media entity name
+ *
+ * Releasing memory of the newly created instance is responsibility of the
+ * caller of this function.
+ *
+ * \return A newly created V4L2Subdevice on success, nullptr otherwise
+ */
+V4L2Subdevice *V4L2Subdevice::fromEntityName(const MediaDevice *media,
+					     const std::string &name)
+{
+	MediaEntity *entity = media->getEntityByName(name);
+	if (!entity)
+		return nullptr;
+
+	return new V4L2Subdevice(entity);
+}
+
 /**
  * \brief Create a V4L2 subdevice from a MediaEntity using its device node
  * path
-- 
2.21.0