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path: root/src/v4l2/v4l2_camera.cpp
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2020-06-25v4l2: v4l2_compat: Support multiple openPaul Elder
Previously, since we acquired the libcamera camera upon open(), it was impossible to support multiple open, as any subsequent opens would return error because the camera would already be acquired. To fix this, we first initialize the camera in the first call to V4L2CameraProxy::open(), just to heat up the stream format cache. We then add ownership by a V4L2CameraFile of a V4L2Camera via the V4L2CameraProxy. All vidioc ioctls prior to reqbufs > 0 (except for s_fmt) are able to access the camera without ownership. A call to reqbufs > 0 (and s_fmt) will take ownership, and the ownership will be released at reqbufs = 0. While ownership is assigned, the eventfd that should be signaled (and cleared) by V4L2Camera and V4L2CameraProxy is set to the V4L2CameraFile that has ownership, and is cleared when the ownership is released. In case close() is called without a reqbufs = 0 first, the ownership is also released on close(). We also use the V4L2CameraFile to contain all the information specific to an open instance of the file. This removes the need to keep track of such information within V4L2CameraProxy via multiple maps from int fd to info. Since V4L2 does not expect reqbufs 0 to ever return error, make V4L2CameraProxy::freeBuffers() return void. Signed-off-by: Paul Elder <paul.elder@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2020-06-17v4l2: v4l2_camera_proxy, v4l2_camera: Check return values of read/writePaul Elder
The return value of the write to the eventfd (to signal POLLIN) from V4L2Camera and the read from the eventfd (to clear POLLIN) from V4L2CameraProxy was ignored. Check the return value, and print an error message. Reported-by: Coverity CID=290743 Reported-by: Coverity CID=290744 Signed-off-by: Paul Elder <paul.elder@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2020-06-08v4l2: v4l2_compat: Add eventfd signaling to support pollingPaul Elder
To support polling, we need to be able to signal when data is available to be read (POLLIN), as well as events (POLLPRI). Add the necessary calls to eventfd to allow signaling POLLIN. We signal POLLIN by writing writing to the eventfd, and clear it by reading from the eventfd, upon VIDIOC_DQBUF. Note that eventfd does not support signaling POLLPRI, so we don't yet support V4L2 events. Signed-off-by: Paul Elder <paul.elder@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2020-05-28v4l2: Relicense V4L2 compatibility layer under LGPLLaurent Pinchart
The V4L2 compatibility layer is licensed under the GPL. It is compiled as a binary separate from libcamera.so, and is loaded into the address space of processes through LD_PRELOAD to intercept calls to the C library. It is our understanding and intent that the GPL license doesn't propagate to the binaries whose calls are intercepted, considering those binaries are not derivative work of the V4L2 compatibility layer and are not designed to be linked to the V4L2 compatibility layer. There is however a possibly grey area if binaries are packaged with a shell script wrapper that loads the V4L2 compatibility layer. This could lead to license-related issues if such packaging is performed by Linux distributions or system integrators. To clarify the intent and lift the doubts, relicense the V4L2 compatibility layer under the LGPL. The V4L2 compatibility layer code itself still benefits from the license protection, while its usage with third-party binaries is clearly allowed as intended. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Acked-by: Jacopo Mondi <jacopo@jmondi.org> Acked-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Acked-by: Paul Elder <paul.elder@ideasonboard.com> Acked-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> Acked-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
2020-05-16libcamera: Move internal headers to include/libcamera/internal/Laurent Pinchart
The libcamera internal headers are located in src/libcamera/include/. The directory is added to the compiler headers search path with a meson include_directories() directive, and internal headers are included with (e.g. for the internal semaphore.h header) #include "semaphore.h" All was well, until libcxx decided to implement the C++20 synchronization library. The __threading_support header gained a #include <semaphore.h> to include the pthread's semaphore support. As include_directories() adds src/libcamera/include/ to the compiler search path with -I, the internal semaphore.h is included instead of the pthread version. Needless to say, the compiler isn't happy. Three options have been considered to fix this issue: - Use -iquote instead of -I. The -iquote option instructs gcc to only consider the header search path for headers included with the "" version. Meson unfortunately doesn't support this option. - Rename the internal semaphore.h header. This was deemed to be the beginning of a long whack-a-mole game, where namespace clashes with system libraries would appear over time (possibly dependent on particular system configurations) and would need to be constantly fixed. - Move the internal headers to another directory to create a unique namespace through path components. This causes lots of churn in all the existing source files through the all project. The first option would be best, but isn't available to us due to missing support in meson. Even if -iquote support was added, we would need to fix the problem before a new version of meson containing the required support would be released. The third option is thus the only practical solution available. Bite the bullet, and do it, moving headers to include/libcamera/internal/. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Acked-by: Jacopo Mondi <jacopo@jmondi.org>
2020-03-18libcamera: framebuffer_allocator: Lift camera restrictions on allocatorLaurent Pinchart
The Camera class currently requires the allocator to have no allocated buffer before the camera is reconfigured, and the allocator to be destroyed before the camera is released. There's no basis for these restrictions anymore, remove them. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
2020-03-18libcamera: PixelFormat: Mark all function arguments of type PixelFormat as ↵Niklas Söderlund
const reference PixelFormat was previously an alias for unsigned int but is now a class. Make all functions taking PixelFormat do so as a const reference. Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2020-01-14libcamera: Switch from utils::make_unique to std::make_uniqueLaurent Pinchart
Now that we're using C++-14, drop utils::make_unique for std::make_unique. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
2020-01-12libcamera: camera: Remove the prepared stateNiklas Söderlund
With the FrameBuffer rework completed there is no reason to keep the camera prepared state around as buffer allocations are now decoupled from the camera state. Remove the camera state simplifying the API. Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2020-01-12libcamera: Switch to FrameBuffer interfaceNiklas Söderlund
Switch to the FrameBuffer interface where all buffers are treated as external buffers and are allocated outside the camera. Applications allocating buffers using libcamera are switched to use the FrameBufferAllocator helper. Follow-up changes to this one will finalize the transition to the new FrameBuffer interface by removing code that is left unused after this change. Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2020-01-12libcamera: buffer: Move captured metadata to FrameMetadataNiklas Söderlund
Move the metadata retrieved when dequeuing a V4L2 buffer into a FrameMetadata object. This is done as a step to migrate to the FrameBuffer interface as the functions added to Buffer around FrameMetadata match the ones in FrameBuffer. Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2020-01-12libcamera: request: In addBuffer() do not fetch stream from BufferNiklas Söderlund
In the FrameBuffer interface the stream will not be available from the buffer object as the buffer might be allocated externally. The application needs to explicitly state which stream the buffer is being added for to the request. Extend the addBuffer() function to get this information explicitly from the caller. Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> Reviewed-by: Jacopo Mondi <jacopo@jmondi.org> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2020-01-12libcamera: buffer: Switch from Plane to FrameBuffer::PlaneNiklas Söderlund
It is not libcamera's responsibility to handle memory mappings. Switch from the soon to be removed Plane class which deals with memory mappings to FrameBuffer::Plane which just describes it. This makes the transition to the full FrameBuffer easier. As the full FrameBuffer interface has not yet spread to all parts of libcamera core it is hard to create efficient caching of memory mappings in the qcam application. This will be fixed in a later patch, for now the dmabuf is mapped and unmapped each time it is seen by the application. Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> Reviewed-by: Jacopo Mondi <jacopo@jmondi.org> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2020-01-12v4l2: camera: Handle memory mapping of buffers directlyNiklas Söderlund
In the upcoming FrameBuffer API the memory mapping of buffers will be left to the user of the FrameBuffer objects. Prepare the V4L2 compatibility layer to this upcoming change to ease conversion to the new API. Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2020-01-12v4l2: Rename FrameMetadata to V4L2FrameMetadataNiklas Söderlund
With the upcoming FrameBuffer API a new library wide FrameMetadata object will be added which will replace the specific implementation in the V4L2 compatibility layer. Avoid name collisions while the new FrameBuffer API is added by renaming the V4L2 compatibility layer specific implementation until it can be replaced with the library wide implementation. Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2020-01-07v4l2: Use Object::invokeMethod() return valueLaurent Pinchart
Now that Object::invokeMethod() supports returning a value, use it and drop the return value method argument. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
2020-01-03v4l2: v4l2_compat: Add V4L2 compatibility layerPaul Elder
Add libcamera V4L2 compatibility layer. This initial implementation supports the minimal set of V4L2 operations, which allows getting, setting, and enumerating formats, and streaming frames from a video device. Some data about the wrapped V4L2 video device are hardcoded. Add a build option named 'v4l2' and adjust the build system to selectively compile the V4L2 compatibility layer. For now we match the V4L2 device node to a libcamera camera based on a devnum that a pipeline handler may optionally map to a libcamera camera. Signed-off-by: Paul Elder <paul.elder@ideasonboard.com> Reviewed-by: Jacopo Mondi <jacopo@jmondi.org> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>