diff options
| -rw-r--r-- | src/libcamera/include/v4l2_device.h | 1 | ||||
| -rw-r--r-- | src/libcamera/v4l2_device.cpp | 26 |
2 files changed, 27 insertions, 0 deletions
diff --git a/src/libcamera/include/v4l2_device.h b/src/libcamera/include/v4l2_device.h index e7e9829c..75a52c33 100644 --- a/src/libcamera/include/v4l2_device.h +++ b/src/libcamera/include/v4l2_device.h @@ -35,6 +35,7 @@ protected: ~V4L2Device(); int open(unsigned int flags); + int setFd(int fd); int ioctl(unsigned long request, void *argp); diff --git a/src/libcamera/v4l2_device.cpp b/src/libcamera/v4l2_device.cpp index 9a00566a..f8954661 100644 --- a/src/libcamera/v4l2_device.cpp +++ b/src/libcamera/v4l2_device.cpp @@ -89,6 +89,32 @@ int V4L2Device::open(unsigned int flags) } /** + * \brief Set the file descriptor of a V4L2 device + * \param[in] fd The file descriptor handle + * + * This method allows a device to provide an already opened file descriptor + * referring to the V4L2 device node, instead of opening it with open(). This + * can be used for V4L2 M2M devices where a single video device node is used for + * both the output and capture devices, or when receiving an open file + * descriptor in a context that doesn't have permission to open the device node + * itself. + * + * This method and the open() method are mutually exclusive, only one of the two + * shall be used for a V4L2Device instance. + * + * \return 0 on success or a negative error code otherwise + */ +int V4L2Device::setFd(int fd) +{ + if (isOpen()) + return -EBUSY; + + fd_ = fd; + + return 0; +} + +/** * \brief Close the device node * * Reset the file descriptor to -1 |