[libcamera-devel] [PATCH 1/3] pipeline: uvcvideo: Move camera ID generation to UVCCameraData class

[Laurent Pinchart]

Move the camera ID generation to UVCCameraData, and cache the ID in that
class. This will be useful to access the ID in multiple locations, such
as when printing error messages.

Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
---
 src/libcamera/pipeline/uvcvideo/uvcvideo.cpp | 149 ++++++++++---------
 1 file changed, 78 insertions(+), 71 deletions(-)

diff --git a/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp b/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp
index 2ae640a31f68..22b67faf309e 100644
--- a/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp
+++ b/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp
@@ -46,8 +46,15 @@ public:
 			ControlInfoMap::Map *ctrls);
 	void bufferReady(FrameBuffer *buffer);
 
+	const std::string &id() const { return id_; }
+
 	std::unique_ptr<V4L2VideoDevice> video_;
 	Stream stream_;
+
+private:
+	bool generateId();
+
+	std::string id_;
 };
 
 class UVCCameraConfiguration : public CameraConfiguration
@@ -81,8 +88,6 @@ public:
 	bool match(DeviceEnumerator *enumerator) override;
 
 private:
-	std::string generateId(const UVCCameraData *data);
-
 	int processControl(ControlList *controls, unsigned int id,
 			   const ControlValue &value);
 	int processControls(UVCCameraData *data, Request *request);
@@ -384,69 +389,6 @@ int PipelineHandlerUVC::queueRequestDevice(Camera *camera, Request *request)
 	return 0;
 }
 
-std::string PipelineHandlerUVC::generateId(const UVCCameraData *data)
-{
-	const std::string path = data->video_->devicePath();
-
-	/* Create a controller ID from first device described in firmware. */
-	std::string controllerId;
-	std::string searchPath = path;
-	while (true) {
-		std::string::size_type pos = searchPath.rfind('/');
-		if (pos <= 1) {
-			LOG(UVC, Error) << "Can not find controller ID";
-			return {};
-		}
-
-		searchPath = searchPath.substr(0, pos);
-
-		controllerId = sysfs::firmwareNodePath(searchPath);
-		if (!controllerId.empty())
-			break;
-	}
-
-	/*
-	 * Create a USB ID from the device path which has the known format:
-	 *
-	 *	path = bus, "-", ports, ":", config, ".", interface ;
-	 *	bus = number ;
-	 *	ports = port, [ ".", ports ] ;
-	 *	port = number ;
-	 *	config = number ;
-	 *	interface = number ;
-	 *
-	 * Example: 3-2.4:1.0
-	 *
-	 * The bus is not guaranteed to be stable and needs to be stripped from
-	 * the USB ID. The final USB ID is built up of the ports, config and
-	 * interface properties.
-	 *
-	 * Example 2.4:1.0.
-	 */
-	std::string usbId = utils::basename(path.c_str());
-	usbId = usbId.substr(usbId.find('-') + 1);
-
-	/* Creata a device ID from the USB devices vendor and product ID. */
-	std::string deviceId;
-	for (const char *name : { "idVendor", "idProduct" }) {
-		std::ifstream file(path + "/../" + name);
-
-		if (!file.is_open())
-			return {};
-
-		std::string value;
-		std::getline(file, value);
-		file.close();
-
-		if (!deviceId.empty())
-			deviceId += ":";
-
-		deviceId += value;
-	}
-
-	return controllerId + "-" + usbId + "-" + deviceId;
-}
-
 bool PipelineHandlerUVC::match(DeviceEnumerator *enumerator)
 {
 	MediaDevice *media;
@@ -462,12 +404,7 @@ bool PipelineHandlerUVC::match(DeviceEnumerator *enumerator)
 		return false;
 
 	/* Create and register the camera. */
-	std::string id = generateId(data.get());
-	if (id.empty()) {
-		LOG(UVC, Error) << "Failed to generate camera ID";
-		return false;
-	}
-
+	std::string id = data->id();
 	std::set<Stream *> streams{ &data->stream_ };
 	std::shared_ptr<Camera> camera =
 		Camera::create(std::move(data), id, streams);
@@ -502,6 +439,12 @@ int UVCCameraData::init(MediaDevice *media)
 
 	video_->bufferReady.connect(this, &UVCCameraData::bufferReady);
 
+	/* Generate the camera ID. */
+	if (!generateId()) {
+		LOG(UVC, Error) << "Failed to generate camera ID";
+		return -EINVAL;
+	}
+
 	properties_.set(properties::Model, utils::toAscii(media->model()));
 
 	/*
@@ -563,6 +506,70 @@ int UVCCameraData::init(MediaDevice *media)
 	return 0;
 }
 
+bool UVCCameraData::generateId()
+{
+	const std::string path = video_->devicePath();
+
+	/* Create a controller ID from first device described in firmware. */
+	std::string controllerId;
+	std::string searchPath = path;
+	while (true) {
+		std::string::size_type pos = searchPath.rfind('/');
+		if (pos <= 1) {
+			LOG(UVC, Error) << "Can not find controller ID";
+			return false;
+		}
+
+		searchPath = searchPath.substr(0, pos);
+
+		controllerId = sysfs::firmwareNodePath(searchPath);
+		if (!controllerId.empty())
+			break;
+	}
+
+	/*
+	 * Create a USB ID from the device path which has the known format:
+	 *
+	 *	path = bus, "-", ports, ":", config, ".", interface ;
+	 *	bus = number ;
+	 *	ports = port, [ ".", ports ] ;
+	 *	port = number ;
+	 *	config = number ;
+	 *	interface = number ;
+	 *
+	 * Example: 3-2.4:1.0
+	 *
+	 * The bus is not guaranteed to be stable and needs to be stripped from
+	 * the USB ID. The final USB ID is built up of the ports, config and
+	 * interface properties.
+	 *
+	 * Example 2.4:1.0.
+	 */
+	std::string usbId = utils::basename(path.c_str());
+	usbId = usbId.substr(usbId.find('-') + 1);
+
+	/* Creata a device ID from the USB devices vendor and product ID. */
+	std::string deviceId;
+	for (const char *name : { "idVendor", "idProduct" }) {
+		std::ifstream file(path + "/../" + name);
+
+		if (!file.is_open())
+			return false;
+
+		std::string value;
+		std::getline(file, value);
+		file.close();
+
+		if (!deviceId.empty())
+			deviceId += ":";
+
+		deviceId += value;
+	}
+
+	id_ = controllerId + "-" + usbId + "-" + deviceId;
+	return true;
+}
+
 void UVCCameraData::addControl(uint32_t cid, const ControlInfo &v4l2Info,
 			       ControlInfoMap::Map *ctrls)
 {
-- 
Regards,

Laurent Pinchart