diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/libcamera/v4l2_subdevice.cpp | 50 |
1 files changed, 49 insertions, 1 deletions
diff --git a/src/libcamera/v4l2_subdevice.cpp b/src/libcamera/v4l2_subdevice.cpp index 37960b76..a1672b23 100644 --- a/src/libcamera/v4l2_subdevice.cpp +++ b/src/libcamera/v4l2_subdevice.cpp @@ -134,6 +134,30 @@ const std::map<uint32_t, V4L2SubdeviceFormatInfo> formatInfoMap = { } /* namespace */ /** + * \struct V4L2SubdeviceCapability + * \brief struct v4l2_subdev_capability object wrapper and helpers + * + * The V4L2SubdeviceCapability structure manages the information returned by the + * VIDIOC_SUBDEV_QUERYCAP ioctl. + */ + +/** + * \fn V4L2SubdeviceCapability::isReadOnly() + * \brief Retrieve if a subdevice is registered as read-only + * + * A V4L2 subdevice is registered as read-only if V4L2_SUBDEV_CAP_RO_SUBDEV + * is listed as part of its capabilities. + * + * \return True if the subdevice is registered as read-only, false otherwise + */ + +/** + * \fn V4L2SubdeviceCapability::hasStreams() + * \brief Retrieve if a subdevice supports the V4L2 streams API + * \return True if the subdevice supports the streams API, false otherwise + */ + +/** * \struct V4L2SubdeviceFormat * \brief The V4L2 sub-device image format and sizes * @@ -284,7 +308,25 @@ V4L2Subdevice::~V4L2Subdevice() */ int V4L2Subdevice::open() { - return V4L2Device::open(O_RDWR); + int ret = V4L2Device::open(O_RDWR); + if (ret) + return ret; + + /* + * Try to query the subdev capabilities. The VIDIOC_SUBDEV_QUERYCAP API + * was introduced in kernel v5.8, ENOTTY errors must be ignored to + * support older kernels. + */ + caps_ = {}; + ret = ioctl(VIDIOC_SUBDEV_QUERYCAP, &caps_); + if (ret < 0 && errno != ENOTTY) { + ret = -errno; + LOG(V4L2, Error) + << "Unable to query capabilities: " << strerror(-ret); + return ret; + } + + return 0; } /** @@ -528,6 +570,12 @@ const std::string &V4L2Subdevice::model() } /** + * \fn V4L2Subdevice::caps() + * \brief Retrieve the subdevice V4L2 capabilities + * \return The subdevice V4L2 capabilities + */ + +/** * \brief Create a new video subdevice instance from \a entity in media device * \a media * \param[in] media The media device where the entity is registered |