@@ -30,6 +30,7 @@ public:
int setControls(ControlList *ctrls);
const std::string &deviceNode() const { return deviceNode_; }
+ std::string devicePath() const;
protected:
V4L2Device(const std::string &deviceNode);
@@ -9,6 +9,7 @@
#include <fcntl.h>
#include <iomanip>
+#include <limits.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/syscall.h>
@@ -350,6 +351,29 @@ int V4L2Device::setControls(ControlList *ctrls)
return ret;
}
+/**
+ * \brief Retrieve the device path
+ *
+ * The device path describes the device backing the V4L2 device.
+ *
+ * \todo When switching to C++17 use std::filesystem:: in the implementation.
+ * \todo Query udev for this information as the path created for vdev here
+ * migh not be correct.
+ *
+ * \return The device path
+ */
+std::string V4L2Device::devicePath() const
+{
+ std::string vdev = basename(deviceNode_.c_str());
+ std::string sysfs = "/sys/class/video4linux/" + vdev + "/device";
+
+ char path[PATH_MAX];
+ if (!realpath(sysfs.c_str(), path))
+ LOG(V4L2, Fatal) << "Can not resolve path for " << deviceNode_;
+
+ return path;
+}
+
/**
* \brief Perform an IOCTL system call on the device node
* \param[in] request The IOCTL request code
Add a method to lookup a V4L2 devices path in sysfs. Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> --- include/libcamera/internal/v4l2_device.h | 1 + src/libcamera/v4l2_device.cpp | 24 ++++++++++++++++++++++++ 2 files changed, 25 insertions(+)