diff options
| author | Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com> | 2025-04-03 09:45:47 +0200 |
|---|---|---|
| committer | Kieran Bingham <kieran.bingham@ideasonboard.com> | 2025-04-03 09:36:11 +0100 |
| commit | b2eccef711e621748c90fe5bf69ae91d1bd901e8 (patch) | |
| tree | 120b6062178617235efcf8dc57fd884922bc5438 /src | |
| parent | a2a7f4fc2d2a3fa7e5cb1b7d35b369d64f86c2ab (diff) | |
libcamera: v4l2_device: add frame start event helpers
Add helper to check if frame start event are supported by subdevice.
Since kernel does not have interface to query supported events
use subscribe interface.
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> # v3
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> # v5
Signed-off-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Diffstat (limited to 'src')
| -rw-r--r-- | src/libcamera/v4l2_device.cpp | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/src/libcamera/v4l2_device.cpp b/src/libcamera/v4l2_device.cpp index 2f65a43a..0db92c19 100644 --- a/src/libcamera/v4l2_device.cpp +++ b/src/libcamera/v4l2_device.cpp @@ -450,6 +450,28 @@ std::string V4L2Device::devicePath() const } /** + * \brief Check if frame start event is supported + * + * Due to limitations in the kernel API, this function may disable the frame + * start event as a side effect. It should only be called during initialization, + * before enabling the frame start event with setFrameStartEnabled(). + * + * \return True if frame start event is supported, false otherwise + */ +bool V4L2Device::supportsFrameStartEvent() +{ + struct v4l2_event_subscription event{}; + event.type = V4L2_EVENT_FRAME_SYNC; + + int ret = ioctl(VIDIOC_SUBSCRIBE_EVENT, &event); + if (ret) + return false; + + ioctl(VIDIOC_UNSUBSCRIBE_EVENT, &event); + return true; +} + +/** * \brief Enable or disable frame start event notification * \param[in] enable True to enable frame start events, false to disable them * |