[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>
This commit is contained in:
Tomasz Stanislawski
2012-06-14 11:32:23 -03:00
committed by Mauro Carvalho Chehab
parent c60520fa50
commit b799d09a15
5 changed files with 42 additions and 0 deletions

View File

@@ -694,6 +694,33 @@ struct v4l2_buffer {
#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 @@ struct v4l2_create_buffers {
#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)