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@xxxxxxxxxxx>
Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
---
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(-)
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);
--
1.7.5.4
--
To unsubscribe from this list: send the line "unsubscribe linux-media" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
