[libcamera-devel] [PATCH 1/6] libcamera: v4l2_device: Add setFd()

[Kieran Bingham]

Provide a means for V4L2 device instances to set the fd_ explicitly.
This allows for V4L2Devices to operate when they must use an external open() call.

Signed-off-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
---
 src/libcamera/include/v4l2_device.h |  1 +
 src/libcamera/v4l2_device.cpp       | 19 +++++++++++++++++++
 2 files changed, 20 insertions(+)

diff --git a/src/libcamera/include/v4l2_device.h b/src/libcamera/include/v4l2_device.h
index e7e9829cb05f..7c3af5f6ebe0 100644
--- a/src/libcamera/include/v4l2_device.h
+++ b/src/libcamera/include/v4l2_device.h
@@ -39,6 +39,7 @@ protected:
 	int ioctl(unsigned long request, void *argp);
 
 	int fd() { return fd_; }
+	int setFd(int fd);
 
 private:
 	void listControls();
diff --git a/src/libcamera/v4l2_device.cpp b/src/libcamera/v4l2_device.cpp
index 9a00566a532b..120f68e49d7a 100644
--- a/src/libcamera/v4l2_device.cpp
+++ b/src/libcamera/v4l2_device.cpp
@@ -308,6 +308,25 @@ int V4L2Device::ioctl(unsigned long request, void *argp)
  * \return The V4L2 device file descriptor, -1 if the device node is not open
  */
 
+/**
+ * \brief Set the file descriptor of a V4L2 device.
+ * \param[in] fd The file descriptor handle
+ *
+ * Allow a device to set the internal file descriptor rather than opening a
+ * device node directly.
+ *
+ * \return 0 on success or a negative error code otherwise
+ */
+int V4L2Device::setFd(int fd)
+{
+	if (fd_ != -1)
+		return -1;
+
+	fd_ = fd;
+
+	return 0;
+}
+
 /*
  * \brief List and store information about all controls supported by the
  * V4L2 device
-- 
2.20.1