[media] v4l: add buffer exporting via dmabuf
This patch adds extension to V4L2 api. A new ioctl VIDIOC_EXPBUF is added. The
ioctl is used to export an mmap buffer as a DMABUF file descriptor.
Signed-off-by: Tomasz Stanislawski <t.stanislaws@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Tested-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index 91ac83b..3cf3e94 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -694,6 +694,33 @@
#define V4L2_BUF_FLAG_NO_CACHE_INVALIDATE 0x0800
#define V4L2_BUF_FLAG_NO_CACHE_CLEAN 0x1000
+/**
+ * struct v4l2_exportbuffer - export of video buffer as DMABUF file descriptor
+ *
+ * @index: id number of the buffer
+ * @type: enum v4l2_buf_type; buffer type (type == *_MPLANE for
+ * multiplanar buffers);
+ * @plane: index of the plane to be exported, 0 for single plane queues
+ * @flags: flags for newly created file, currently only O_CLOEXEC is
+ * supported, refer to manual of open syscall for more details
+ * @fd: file descriptor associated with DMABUF (set by driver)
+ *
+ * Contains data used for exporting a video buffer as DMABUF file descriptor.
+ * The buffer is identified by a 'cookie' returned by VIDIOC_QUERYBUF
+ * (identical to the cookie used to mmap() the buffer to userspace). All
+ * reserved fields must be set to zero. The field reserved0 is expected to
+ * become a structure 'type' allowing an alternative layout of the structure
+ * content. Therefore this field should not be used for any other extensions.
+ */
+struct v4l2_exportbuffer {
+ __u32 type; /* enum v4l2_buf_type */
+ __u32 index;
+ __u32 plane;
+ __u32 flags;
+ __s32 fd;
+ __u32 reserved[11];
+};
+
/*
* O V E R L A Y P R E V I E W
*/
@@ -1895,6 +1922,7 @@
#define VIDIOC_S_FBUF _IOW('V', 11, struct v4l2_framebuffer)
#define VIDIOC_OVERLAY _IOW('V', 14, int)
#define VIDIOC_QBUF _IOWR('V', 15, struct v4l2_buffer)
+#define VIDIOC_EXPBUF _IOWR('V', 16, struct v4l2_exportbuffer)
#define VIDIOC_DQBUF _IOWR('V', 17, struct v4l2_buffer)
#define VIDIOC_STREAMON _IOW('V', 18, int)
#define VIDIOC_STREAMOFF _IOW('V', 19, int)