| Message ID | 1334063447-16824-2-git-send-email-t.stanislaws@samsung.com |
|---|---|
| State | Superseded, archived |
| Headers | show |
Hi Tomasz, Thanks for the patch. On Tuesday 10 April 2012 15:10:35 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> This mostly looks good to me, except for the lack of documentation of course :-) > --- > drivers/media/video/v4l2-compat-ioctl32.c | 1 + > drivers/media/video/v4l2-ioctl.c | 7 +++++++ > include/linux/videodev2.h | 23 +++++++++++++++++++++++ > include/media/v4l2-ioctl.h | 2 ++ > 4 files changed, 33 insertions(+), 0 deletions(-) [snip] > diff --git a/include/linux/videodev2.h b/include/linux/videodev2.h > index 38259bf..627e235 100644 > --- a/include/linux/videodev2.h > +++ b/include/linux/videodev2.h > @@ -680,6 +680,28 @@ 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) > + * @mem_offset: a "cookie" that is passed to mmap() as offset I wouldn't mention mmap() here, as that's unrelated to the DMABUF exporter API. Maybe something like "buffer memory offset as returned by VIDIOC_QUERYBUF in struct v4l2_buffer::m.offset (for single-plane formats) or v4l2_plane::m.offset (for multi-planar formats)" > + * @flags: flags for newly created file, currently only O_CLOEXEC is > + * supported, refer to manual of open syscall for more details > + * > + * Contains data used for exporting a video buffer as DMABUF file > + *descriptor. Uses the same 'cookie' as mmap() syscall. 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 fd; > + __u32 reserved0; > + __u32 mem_offset; > + __u32 flags; > + __u32 reserved[12]; > +};
diff --git a/drivers/media/video/v4l2-compat-ioctl32.c b/drivers/media/video/v4l2-compat-ioctl32.c index 2829d25..f32b291 100644 --- a/drivers/media/video/v4l2-compat-ioctl32.c +++ b/drivers/media/video/v4l2-compat-ioctl32.c @@ -954,6 +954,7 @@ 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-ioctl.c b/drivers/media/video/v4l2-ioctl.c index 5b2ec1f..3ca9d68 100644 --- a/drivers/media/video/v4l2-ioctl.c +++ b/drivers/media/video/v4l2-ioctl.c @@ -207,6 +207,7 @@ static const char *v4l2_ioctls[] = { [_IOC_NR(VIDIOC_S_FBUF)] = "VIDIOC_S_FBUF", [_IOC_NR(VIDIOC_OVERLAY)] = "VIDIOC_OVERLAY", [_IOC_NR(VIDIOC_QBUF)] = "VIDIOC_QBUF", + [_IOC_NR(VIDIOC_EXPBUF)] = "VIDIOC_EXPBUF", [_IOC_NR(VIDIOC_DQBUF)] = "VIDIOC_DQBUF", [_IOC_NR(VIDIOC_STREAMON)] = "VIDIOC_STREAMON", [_IOC_NR(VIDIOC_STREAMOFF)] = "VIDIOC_STREAMOFF", @@ -938,6 +939,12 @@ static long __video_do_ioctl(struct file *file, dbgbuf(cmd, vfd, p); break; } + case VIDIOC_EXPBUF: + { + if (ops->vidioc_expbuf) + ret = ops->vidioc_expbuf(file, fh, arg); + break; + } case VIDIOC_DQBUF: { struct v4l2_buffer *p = arg; diff --git a/include/linux/videodev2.h b/include/linux/videodev2.h index 38259bf..627e235 100644 --- a/include/linux/videodev2.h +++ b/include/linux/videodev2.h @@ -680,6 +680,28 @@ 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) + * @mem_offset: a "cookie" that is passed to mmap() as offset + * @flags: flags for newly created file, currently only O_CLOEXEC is + * supported, refer to manual of open syscall for more details + * + * Contains data used for exporting a video buffer as DMABUF file + * descriptor. Uses the same 'cookie' as mmap() syscall. 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 fd; + __u32 reserved0; + __u32 mem_offset; + __u32 flags; + __u32 reserved[12]; +}; + /* * O V E R L A Y P R E V I E W */ @@ -2327,6 +2349,7 @@ 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 3cb939c..c161ec3 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_dqbuf) (struct file *file, void *fh, struct v4l2_buffer *b); int (*vidioc_create_bufs)(struct file *file, void *fh, struct v4l2_create_buffers *b);