On Tue October 2 2012 16:27:29 Tomasz Stanislawski wrote:
This patch adds extension to V4L2 api. It allow to export a mmap buffer as file descriptor. New ioctl VIDIOC_EXPBUF is added. It takes a buffer offset used by mmap and return a file descriptor on success.
Signed-off-by: Tomasz Stanislawski t.stanislaws@samsung.com Signed-off-by: Kyungmin Park kyungmin.park@samsung.com
drivers/media/video/v4l2-compat-ioctl32.c | 1 + drivers/media/video/v4l2-dev.c | 1 + drivers/media/video/v4l2-ioctl.c | 10 ++++++++++ include/linux/videodev2.h | 28 ++++++++++++++++++++++++++++ include/media/v4l2-ioctl.h | 2 ++ 5 files changed, 42 insertions(+)
diff --git a/drivers/media/video/v4l2-compat-ioctl32.c b/drivers/media/video/v4l2-compat-ioctl32.c index f0b5aba..8788000 100644 --- a/drivers/media/video/v4l2-compat-ioctl32.c +++ b/drivers/media/video/v4l2-compat-ioctl32.c @@ -971,6 +971,7 @@ long v4l2_compat_ioctl32(struct file *file, unsigned int cmd, unsigned long arg) case VIDIOC_S_FBUF32: case VIDIOC_OVERLAY32: case VIDIOC_QBUF32:
- case VIDIOC_EXPBUF: case VIDIOC_DQBUF32: case VIDIOC_STREAMON32: case VIDIOC_STREAMOFF32:
diff --git a/drivers/media/video/v4l2-dev.c b/drivers/media/video/v4l2-dev.c index 07aeafc..c43127c 100644 --- a/drivers/media/video/v4l2-dev.c +++ b/drivers/media/video/v4l2-dev.c @@ -638,6 +638,7 @@ static void determine_valid_ioctls(struct video_device *vdev) SET_VALID_IOCTL(ops, VIDIOC_REQBUFS, vidioc_reqbufs); SET_VALID_IOCTL(ops, VIDIOC_QUERYBUF, vidioc_querybuf); SET_VALID_IOCTL(ops, VIDIOC_QBUF, vidioc_qbuf);
- SET_VALID_IOCTL(ops, VIDIOC_EXPBUF, vidioc_expbuf); SET_VALID_IOCTL(ops, VIDIOC_DQBUF, vidioc_dqbuf); SET_VALID_IOCTL(ops, VIDIOC_OVERLAY, vidioc_overlay); SET_VALID_IOCTL(ops, VIDIOC_G_FBUF, vidioc_g_fbuf);
diff --git a/drivers/media/video/v4l2-ioctl.c b/drivers/media/video/v4l2-ioctl.c index dffd3c9..f3ec8c0 100644 --- a/drivers/media/video/v4l2-ioctl.c +++ b/drivers/media/video/v4l2-ioctl.c @@ -458,6 +458,15 @@ static void v4l_print_buffer(const void *arg, bool write_only) tc->type, tc->flags, tc->frames, *(__u32 *)tc->userbits); } +static void v4l_print_exportbuffer(const void *arg, bool write_only) +{
- const struct v4l2_exportbuffer *p = arg;
- pr_cont("fd=%d, type=%s, index=%u, plane=%u, flags=0x%08x\n",
p->fd, prt_names(p->type, v4l2_type_names),p->index, p->plane, p->flags);+}
static void v4l_print_create_buffers(const void *arg, bool write_only) { const struct v4l2_create_buffers *p = arg; @@ -1947,6 +1956,7 @@ static struct v4l2_ioctl_info v4l2_ioctls[] = { IOCTL_INFO_STD(VIDIOC_S_FBUF, vidioc_s_fbuf, v4l_print_framebuffer, INFO_FL_PRIO), IOCTL_INFO_STD(VIDIOC_OVERLAY, vidioc_overlay, v4l_print_u32, INFO_FL_PRIO), IOCTL_INFO_FNC(VIDIOC_QBUF, v4l_qbuf, v4l_print_buffer, INFO_FL_QUEUE),
- IOCTL_INFO_STD(VIDIOC_EXPBUF, vidioc_expbuf, v4l_print_exportbuffer, 0),
This needs the INFO_FL_QUEUE flag, that way this call is serialized with the other queuing ioctls.
You can also add INFO_FL_CLEAR(v4l2_expbuf, flags). This assumes a field order in the struct as given in my comment below. The FL_CLEAR flag will zero all fields after 'flags'.
IOCTL_INFO_FNC(VIDIOC_DQBUF, v4l_dqbuf, v4l_print_buffer, INFO_FL_QUEUE), IOCTL_INFO_FNC(VIDIOC_STREAMON, v4l_streamon, v4l_print_buftype, INFO_FL_PRIO | INFO_FL_QUEUE), IOCTL_INFO_FNC(VIDIOC_STREAMOFF, v4l_streamoff, v4l_print_buftype, INFO_FL_PRIO | INFO_FL_QUEUE), diff --git a/include/linux/videodev2.h b/include/linux/videodev2.h index e04a73e..f429b6a 100644 --- a/include/linux/videodev2.h +++ b/include/linux/videodev2.h @@ -688,6 +688,33 @@ 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
- @fd: file descriptor associated with DMABUF (set by driver)
- @flags: flags for newly created file, currently only O_CLOEXEC is
supported, refer to manual of open syscall for more details
- @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
- 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 {
- __s32 fd;
- __u32 flags;
- __u32 type; /* enum v4l2_buf_type */
- __u32 index;
- __u32 plane;
As suggested in my comments in the previous patch, I think it is a more natural order to have the type/index/plane fields first in this struct.
Actually, I think that flags should also come before fd:
struct v4l2_exportbuffer { __u32 type; /* enum v4l2_buf_type */ __u32 index; __u32 plane; __u32 flags; __s32 fd; __u32 reserved[11]; };
- __u32 reserved[11];
+};
/*
- O V E R L A Y P R E V I E W
*/ @@ -2558,6 +2585,7 @@ 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) diff --git a/include/media/v4l2-ioctl.h b/include/media/v4l2-ioctl.h index e614c9c..38fb139 100644 --- a/include/media/v4l2-ioctl.h +++ b/include/media/v4l2-ioctl.h @@ -119,6 +119,8 @@ struct v4l2_ioctl_ops { int (*vidioc_reqbufs) (struct file *file, void *fh, struct v4l2_requestbuffers *b); int (*vidioc_querybuf)(struct file *file, void *fh, struct v4l2_buffer *b); int (*vidioc_qbuf) (struct file *file, void *fh, struct v4l2_buffer *b);
- int (*vidioc_expbuf) (struct file *file, void *fh,
struct v4l2_exportbuffer *e);int (*vidioc_create_bufs)(struct file *file, void *fh, struct v4l2_create_buffers *b);