From: Hans Verkuil <hans.verkuil@xxxxxxxxx>
Add support for 'tags' to struct v4l2_buffer. These can be used
by m2m devices so userspace can set a tag for an output buffer and
this value will then be copied to the capture buffer(s).
This tag can be used to refer to capture buffers, something that
is needed by stateless HW codecs.
The new V4L2_BUF_CAP_SUPPORTS_TAGS capability indicates whether
or not tags are supported.
Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
---
include/uapi/linux/videodev2.h | 38 +++++++++++++++++++++++++++++++++-
1 file changed, 37 insertions(+), 1 deletion(-)
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index c8e8ff810190..ec1fef2a9445 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -879,6 +879,7 @@ struct v4l2_requestbuffers {
#define V4L2_BUF_CAP_SUPPORTS_USERPTR (1 << 1)
#define V4L2_BUF_CAP_SUPPORTS_DMABUF (1 << 2)
#define V4L2_BUF_CAP_SUPPORTS_REQUESTS (1 << 3)
+#define V4L2_BUF_CAP_SUPPORTS_TAGS (1 << 4)
/**
* struct v4l2_plane - plane info for multi-planar buffers
@@ -912,6 +913,11 @@ struct v4l2_plane {
__u32 reserved[11];
};
+struct v4l2_buffer_tag {
+ __u32 low;
+ __u32 high;
+};
+
/**
* struct v4l2_buffer - video buffer info
* @index: id number of the buffer
@@ -950,7 +956,10 @@ struct v4l2_buffer {
__u32 flags;
__u32 field;
struct timeval timestamp;
- struct v4l2_timecode timecode;
+ union {
+ struct v4l2_timecode timecode;
+ struct v4l2_buffer_tag tag;
+ };
__u32 sequence;
/* memory location */
@@ -988,6 +997,8 @@ struct v4l2_buffer {
#define V4L2_BUF_FLAG_IN_REQUEST 0x00000080
/* timecode field is valid */
#define V4L2_BUF_FLAG_TIMECODE 0x00000100
+/* tag field is valid */
+#define V4L2_BUF_FLAG_TAG 0x00000200
/* Buffer is prepared for queuing */
#define V4L2_BUF_FLAG_PREPARED 0x00000400
/* Cache handling flags */
@@ -1007,6 +1018,31 @@ struct v4l2_buffer {
/* request_fd is valid */
#define V4L2_BUF_FLAG_REQUEST_FD 0x00800000
+static inline void v4l2_buffer_set_tag(struct v4l2_buffer *buf, __u64 tag)
+{
+ buf->tag.high = tag >> 32;
+ buf->tag.low = tag & 0xffffffffULL;
+ buf->flags |= V4L2_BUF_FLAG_TAG;
+}
+
+static inline void v4l2_buffer_set_tag_ptr(struct v4l2_buffer *buf,
+ const void *tag)
+{
+ v4l2_buffer_set_tag(buf, (uintptr_t)tag);
+}
+
+static inline __u64 v4l2_buffer_get_tag(const struct v4l2_buffer *buf)
+{
+ if (!(buf->flags & V4L2_BUF_FLAG_TAG))
+ return 0;
+ return (((__u64)buf->tag.high) << 32) | (__u64)buf->tag.low;
+}
+
+static inline void *v4l2_buffer_get_tag_ptr(const struct v4l2_buffer *buf)
+{
+ return (void *)(uintptr_t)v4l2_buffer_get_tag(buf);
+}
+
/**
* struct v4l2_exportbuffer - export of video buffer as DMABUF file descriptor
*
--
2.19.1
