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path: root/src/v4l2/v4l2_camera_proxy.h
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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>
2020-06-25v4l2: V4L2CameraProxy: Take V4L2CameraFile as argument for intercepted callsPaul Elder
Prepare for using the V4L2CameraFile as a container for file-specific information in the V4L2 compatibility layer by making it a required argument for all V4L2CameraProxy calls that are directed from V4L2CompatManager, which are intercepted via LD_PRELOAD. Change V4L2CameraFile accordingly. Also change V4L2CompatManager accordingly. Instead of keeping a map of file descriptors to V4L2CameraProxy instances, we keep a map of V4L2CameraFile instances to V4L2CameraProxy instances. When the proxy methods are called, feed the file as a parameter. The dup function is also modified, in that it is removed from V4L2CameraProxy, and is handled completely in V4L2CompatManager, as a map from file descriptors to V4L2CameraFile instances. Signed-off-by: Paul Elder <paul.elder@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2020-06-19v4l2: v4l2_compat: Intercept open64, openat64, and mmap64Paul Elder
Some applications (eg. Firefox, Google Chrome, Skype) use open64, openat64, and mmap64 instead of their non-64 versions that we currently intercept. Intercept these calls as well. _LARGEFILE64_SOURCE needs to be set so that the 64-bit symbols are available and not synonymous to the non-64-bit versions on 64-bit systems. Also, since we set _FILE_OFFSET_BITS to 32 to force the various open and mmap symbols that we export to not be the 64-bit versions, our dlsym to get the original open and mmap calls will not automatically be converted to their 64-bit versions. Since we intercept both 32-bit and 64-bit versions of open and mmap, we should be using the 64-bit version to service both. Fetch the 64-bit versions of openat and mmap directly. musl defines the 64-bit symbols as macros that are equivalent to the non-64-bit symbols, so we put compile guards that check if the 64-bit symbols are defined. Signed-off-by: Paul Elder <paul.elder@ideasonboard.com> Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> Tested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> # Compile with musl Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@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>
2020-03-18libcamera: 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>
2020-01-12v4l2: 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>
2020-01-08v4l2: camera_proxy: Break out try_fmtJacopo Mondi
Calling vidioc_s_fmt() calls vidioc_try_fmt() duplicating prinouts. Breakout try format procedure and call it from both functions. Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>
2020-01-07v4l2: camera_proxy: Rationalize arguments to format helpersLaurent Pinchart
To clarify code, adopt the following rules for format helpers: - All variables representing V4L2 pixel formats shall use uint32_t - All variables representing DRM pixel formats shall use PixelFormat - Functions returning positive values only shall not have a signed return type 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>