[PATCH v2 1/4] v4l: Add metadata buffer type and format

[Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>]

The metadata buffer type is used to transfer metadata between userspace
and kernelspace through a V4L2 buffers queue. It comes with a new
metadata capture capability and format description.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Tested-by: Guennadi Liakhovetski <guennadi.liakhovetski@intel.com>
---
Changes since v1:

- Rebased on top of the DocBook to reST conversion

 Documentation/media/uapi/v4l/buffer.rst          |  8 +++
 Documentation/media/uapi/v4l/dev-meta.rst        | 69 ++++++++++++++++++++++++
 Documentation/media/uapi/v4l/devices.rst         |  1 +
 Documentation/media/uapi/v4l/vidioc-querycap.rst | 14 +++--
 Documentation/media/videodev2.h.rst.exceptions   |  2 +
 drivers/media/v4l2-core/v4l2-compat-ioctl32.c    | 19 +++++++
 drivers/media/v4l2-core/v4l2-dev.c               | 16 +++---
 drivers/media/v4l2-core/v4l2-ioctl.c             | 41 ++++++++++++++
 drivers/media/v4l2-core/videobuf2-v4l2.c         |  3 ++
 include/media/v4l2-ioctl.h                       | 17 ++++++
 include/uapi/linux/videodev2.h                   | 14 +++++
 11 files changed, 195 insertions(+), 9 deletions(-)
 create mode 100644 Documentation/media/uapi/v4l/dev-meta.rst

diff --git a/Documentation/media/uapi/v4l/buffer.rst b/Documentation/media/uapi/v4l/buffer.rst
index 5deb4a46f992..b5177cc63b86 100644
--- a/Documentation/media/uapi/v4l/buffer.rst
+++ b/Documentation/media/uapi/v4l/buffer.rst
@@ -499,6 +499,14 @@ enum v4l2_buf_type
        -  Buffer for Software Defined Radio (SDR) output stream, see
 	  :ref:`sdr`.
 
+    -  .. row 13
+
+       -  ``V4L2_BUF_TYPE_META_CAPTURE``
+
+       -  13
+
+       -  Buffer for metadata capture, see :ref:`metadata`.
+
 
 
 .. _buffer-flags:
diff --git a/Documentation/media/uapi/v4l/dev-meta.rst b/Documentation/media/uapi/v4l/dev-meta.rst
new file mode 100644
index 000000000000..252ed05b4841
--- /dev/null
+++ b/Documentation/media/uapi/v4l/dev-meta.rst
@@ -0,0 +1,69 @@
+.. -*- coding: utf-8; mode: rst -*-
+
+.. _metadata:
+
+******************
+Metadata Interface
+******************
+
+Metadata refers to any non-image data that supplements video frames with
+additional information. This may include statistics computed over the image
+or frame capture parameters supplied by the image source. This interface is
+intended for transfer of metadata to userspace and control of that operation.
+
+The metadata interface is implemented on video capture device nodes. The device
+can be dedicated to metadata or can implement both video and metadata capture
+as specified in its reported capabilities.
+
+.. note::
+
+    This is an :ref:`experimental` interface and may
+    change in the future.
+
+Querying Capabilities
+=====================
+
+Device nodes supporting the metadata interface set the ``V4L2_CAP_META_CAPTURE``
+flag in the ``device_caps`` field of the
+:ref:`v4l2_capability <v4l2-capability>` structure returned by the
+:ref:`VIDIOC_QUERYCAP` ioctl. That flag means the device can capture
+metadata to memory.
+
+At least one of the read/write or streaming I/O methods must be supported.
+
+
+Data Format Negotiation
+=======================
+
+The metadata device uses the :ref:`format` ioctls to select the capture format.
+The metadata buffer content format is bound to that selected format. In addition
+to the basic :ref:`format` ioctls, the :ref:`VIDIOC_ENUM_FMT` ioctl must be
+supported as well.
+
+To use the :ref:`format` ioctls applications set the ``type`` of the
+:ref:`v4l2_format <v4l2-format>` structure to ``V4L2_BUF_TYPE_META_CAPTURE``
+and use the :ref:`v4l2_meta_format <v4l2-meta-format>` ``meta`` member of the
+``fmt`` union as needed per the desired operation. The :ref:`v4l2-meta-format`
+structure contains two fields, ``dataformat`` is set by applications to the V4L2
+FourCC code of the desired format, and ``buffersize`` set by drivers to the
+maximum buffer size (in bytes) required for data transfer.
+
+.. _v4l2-meta-format:
+.. flat-table:: struct v4l2_meta_format
+    :header-rows:  0
+    :stub-columns: 0
+    :widths:       1 1 2
+
+    * - __u32
+      - ``dataformat``
+      - The data format, set by the application. This is a little endian
+        :ref:`four character code <v4l2-fourcc>`. V4L2 defines metadata formats
+        in :ref:`meta-formats`.
+    * - __u32
+      - ``buffersize``
+      - Maximum buffer size in bytes required for data. The value is set by the
+        driver.
+    * - __u8
+      - ``reserved[24]``
+      - This array is reserved for future extensions. Drivers and applications
+        must set it to zero.
diff --git a/Documentation/media/uapi/v4l/devices.rst b/Documentation/media/uapi/v4l/devices.rst
index aed0ce11d1f8..961e7fb62063 100644
--- a/Documentation/media/uapi/v4l/devices.rst
+++ b/Documentation/media/uapi/v4l/devices.rst
@@ -24,3 +24,4 @@ Interfaces
     dev-sdr
     dev-event
     dev-subdev
+    dev-meta
diff --git a/Documentation/media/uapi/v4l/vidioc-querycap.rst b/Documentation/media/uapi/v4l/vidioc-querycap.rst
index b10fed313f99..734fae6fc5e4 100644
--- a/Documentation/media/uapi/v4l/vidioc-querycap.rst
+++ b/Documentation/media/uapi/v4l/vidioc-querycap.rst
@@ -387,6 +387,14 @@ specification the ioctl returns an ``EINVAL`` error code.
 
     -  .. row 23
 
+       -  ``V4L2_CAP_META_CAPTURE``
+
+       -  0x00800000
+
+       -  The device supports the :ref:`metadata` capture interface.
+
+    -  .. row 24
+
        -  ``V4L2_CAP_READWRITE``
 
        -  0x01000000
@@ -394,7 +402,7 @@ specification the ioctl returns an ``EINVAL`` error code.
        -  The device supports the :ref:`read() <rw>` and/or
 	  :ref:`write() <rw>` I/O methods.
 
-    -  .. row 24
+    -  .. row 25
 
        -  ``V4L2_CAP_ASYNCIO``
 
@@ -402,7 +410,7 @@ specification the ioctl returns an ``EINVAL`` error code.
 
        -  The device supports the :ref:`asynchronous <async>` I/O methods.
 
-    -  .. row 25
+    -  .. row 26
 
        -  ``V4L2_CAP_STREAMING``
 
@@ -410,7 +418,7 @@ specification the ioctl returns an ``EINVAL`` error code.
 
        -  The device supports the :ref:`streaming <mmap>` I/O method.
 
-    -  .. row 26
+    -  .. row 27
 
        -  ``V4L2_CAP_DEVICE_CAPS``
 
diff --git a/Documentation/media/videodev2.h.rst.exceptions b/Documentation/media/videodev2.h.rst.exceptions
index 9bb9a6cc39d8..d1275725d367 100644
--- a/Documentation/media/videodev2.h.rst.exceptions
+++ b/Documentation/media/videodev2.h.rst.exceptions
@@ -27,6 +27,7 @@ replace symbol V4L2_FIELD_SEQ_TB v4l2-field
 replace symbol V4L2_FIELD_TOP v4l2-field
 
 # Documented enum v4l2_buf_type
+replace symbol V4L2_BUF_TYPE_META_CAPTURE v4l2-buf-type
 replace symbol V4L2_BUF_TYPE_SDR_CAPTURE v4l2-buf-type
 replace symbol V4L2_BUF_TYPE_SDR_OUTPUT v4l2-buf-type
 replace symbol V4L2_BUF_TYPE_SLICED_VBI_CAPTURE v4l2-buf-type
@@ -148,6 +149,7 @@ replace define V4L2_CAP_MODULATOR device-capabilities
 replace define V4L2_CAP_SDR_CAPTURE device-capabilities
 replace define V4L2_CAP_EXT_PIX_FORMAT device-capabilities
 replace define V4L2_CAP_SDR_OUTPUT device-capabilities
+replace define V4L2_CAP_META_CAPTURE device-capabilities
 replace define V4L2_CAP_READWRITE device-capabilities
 replace define V4L2_CAP_ASYNCIO device-capabilities
 replace define V4L2_CAP_STREAMING device-capabilities
diff --git a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
index bacecbd68a6d..da2d836e8887 100644
--- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
+++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
@@ -161,6 +161,20 @@ static inline int put_v4l2_sdr_format(struct v4l2_sdr_format *kp, struct v4l2_sd
 	return 0;
 }
 
+static inline int get_v4l2_meta_format(struct v4l2_meta_format *kp, struct v4l2_meta_format __user *up)
+{
+	if (copy_from_user(kp, up, sizeof(struct v4l2_meta_format)))
+		return -EFAULT;
+	return 0;
+}
+
+static inline int put_v4l2_meta_format(struct v4l2_meta_format *kp, struct v4l2_meta_format __user *up)
+{
+	if (copy_to_user(up, kp, sizeof(struct v4l2_meta_format)))
+		return -EFAULT;
+	return 0;
+}
+
 struct v4l2_format32 {
 	__u32	type;	/* enum v4l2_buf_type */
 	union {
@@ -170,6 +184,7 @@ struct v4l2_format32 {
 		struct v4l2_vbi_format	vbi;
 		struct v4l2_sliced_vbi_format	sliced;
 		struct v4l2_sdr_format	sdr;
+		struct v4l2_meta_format	meta;
 		__u8	raw_data[200];        /* user-defined */
 	} fmt;
 };
@@ -216,6 +231,8 @@ static int __get_v4l2_format32(struct v4l2_format *kp, struct v4l2_format32 __us
 	case V4L2_BUF_TYPE_SDR_CAPTURE:
 	case V4L2_BUF_TYPE_SDR_OUTPUT:
 		return get_v4l2_sdr_format(&kp->fmt.sdr, &up->fmt.sdr);
+	case V4L2_BUF_TYPE_META_CAPTURE:
+		return get_v4l2_meta_format(&kp->fmt.meta, &up->fmt.meta);
 	default:
 		pr_info("compat_ioctl32: unexpected VIDIOC_FMT type %d\n",
 								kp->type);
@@ -263,6 +280,8 @@ static int __put_v4l2_format32(struct v4l2_format *kp, struct v4l2_format32 __us
 	case V4L2_BUF_TYPE_SDR_CAPTURE:
 	case V4L2_BUF_TYPE_SDR_OUTPUT:
 		return put_v4l2_sdr_format(&kp->fmt.sdr, &up->fmt.sdr);
+	case V4L2_BUF_TYPE_META_CAPTURE:
+		return put_v4l2_meta_format(&kp->fmt.meta, &up->fmt.meta);
 	default:
 		pr_info("compat_ioctl32: unexpected VIDIOC_FMT type %d\n",
 								kp->type);
diff --git a/drivers/media/v4l2-core/v4l2-dev.c b/drivers/media/v4l2-core/v4l2-dev.c
index e6da353b39bc..70af31210cd3 100644
--- a/drivers/media/v4l2-core/v4l2-dev.c
+++ b/drivers/media/v4l2-core/v4l2-dev.c
@@ -574,30 +574,34 @@ static void determine_valid_ioctls(struct video_device *vdev)
 		set_bit(_IOC_NR(VIDIOC_ENUM_FREQ_BANDS), valid_ioctls);
 
 	if (is_vid) {
-		/* video specific ioctls */
+		/* video and metadata specific ioctls */
 		if ((is_rx && (ops->vidioc_enum_fmt_vid_cap ||
 			       ops->vidioc_enum_fmt_vid_cap_mplane ||
-			       ops->vidioc_enum_fmt_vid_overlay)) ||
+			       ops->vidioc_enum_fmt_vid_overlay ||
+			       ops->vidioc_enum_fmt_meta_cap)) ||
 		    (is_tx && (ops->vidioc_enum_fmt_vid_out ||
 			       ops->vidioc_enum_fmt_vid_out_mplane)))
 			set_bit(_IOC_NR(VIDIOC_ENUM_FMT), valid_ioctls);
 		if ((is_rx && (ops->vidioc_g_fmt_vid_cap ||
 			       ops->vidioc_g_fmt_vid_cap_mplane ||
-			       ops->vidioc_g_fmt_vid_overlay)) ||
+			       ops->vidioc_g_fmt_vid_overlay ||
+			       ops->vidioc_g_fmt_meta_cap)) ||
 		    (is_tx && (ops->vidioc_g_fmt_vid_out ||
 			       ops->vidioc_g_fmt_vid_out_mplane ||
 			       ops->vidioc_g_fmt_vid_out_overlay)))
 			 set_bit(_IOC_NR(VIDIOC_G_FMT), valid_ioctls);
 		if ((is_rx && (ops->vidioc_s_fmt_vid_cap ||
 			       ops->vidioc_s_fmt_vid_cap_mplane ||
-			       ops->vidioc_s_fmt_vid_overlay)) ||
+			       ops->vidioc_s_fmt_vid_overlay ||
+			       ops->vidioc_s_fmt_meta_cap)) ||
 		    (is_tx && (ops->vidioc_s_fmt_vid_out ||
 			       ops->vidioc_s_fmt_vid_out_mplane ||
 			       ops->vidioc_s_fmt_vid_out_overlay)))
 			 set_bit(_IOC_NR(VIDIOC_S_FMT), valid_ioctls);
 		if ((is_rx && (ops->vidioc_try_fmt_vid_cap ||
 			       ops->vidioc_try_fmt_vid_cap_mplane ||
-			       ops->vidioc_try_fmt_vid_overlay)) ||
+			       ops->vidioc_try_fmt_vid_overlay ||
+			       ops->vidioc_try_fmt_meta_cap)) ||
 		    (is_tx && (ops->vidioc_try_fmt_vid_out ||
 			       ops->vidioc_try_fmt_vid_out_mplane ||
 			       ops->vidioc_try_fmt_vid_out_overlay)))
@@ -663,7 +667,7 @@ static void determine_valid_ioctls(struct video_device *vdev)
 	}
 
 	if (is_vid || is_vbi || is_sdr) {
-		/* ioctls valid for video, vbi or sdr */
+		/* ioctls valid for video, metadata, vbi or sdr */
 		SET_VALID_IOCTL(ops, VIDIOC_REQBUFS, vidioc_reqbufs);
 		SET_VALID_IOCTL(ops, VIDIOC_QUERYBUF, vidioc_querybuf);
 		SET_VALID_IOCTL(ops, VIDIOC_QBUF, vidioc_qbuf);
diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
index 51a0fa144392..0afa07bfea35 100644
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -37,6 +37,13 @@
 	memset((u8 *)(p) + offsetof(typeof(*(p)), field) + sizeof((p)->field), \
 	0, sizeof(*(p)) - offsetof(typeof(*(p)), field) - sizeof((p)->field))
 
+/* Zero out the end of the struct pointed to by p.  Everything including and
+ * after thee specified field is cleared.
+ */
+#define CLEAR_FROM_FIELD(p, field) \
+	memset((u8 *)(p) + offsetof(typeof(*(p)), field), \
+	0, sizeof(*(p)) - offsetof(typeof(*(p)), field))
+
 #define is_valid_ioctl(vfd, cmd) test_bit(_IOC_NR(cmd), (vfd)->valid_ioctls)
 
 struct std_descr {
@@ -155,6 +162,7 @@ const char *v4l2_type_names[] = {
 	[V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE] = "vid-out-mplane",
 	[V4L2_BUF_TYPE_SDR_CAPTURE]        = "sdr-cap",
 	[V4L2_BUF_TYPE_SDR_OUTPUT]         = "sdr-out",
+	[V4L2_BUF_TYPE_META_CAPTURE]       = "meta-cap",
 };
 EXPORT_SYMBOL(v4l2_type_names);
 
@@ -249,6 +257,7 @@ static void v4l_print_format(const void *arg, bool write_only)
 	const struct v4l2_sliced_vbi_format *sliced;
 	const struct v4l2_window *win;
 	const struct v4l2_sdr_format *sdr;
+	const struct v4l2_meta_format *meta;
 	unsigned i;
 
 	pr_cont("type=%s", prt_names(p->type, v4l2_type_names));
@@ -336,6 +345,15 @@ static void v4l_print_format(const void *arg, bool write_only)
 			(sdr->pixelformat >> 16) & 0xff,
 			(sdr->pixelformat >> 24) & 0xff);
 		break;
+	case V4L2_BUF_TYPE_META_CAPTURE:
+		meta = &p->fmt.meta;
+		pr_cont(", dataformat=%c%c%c%c, buffersize=%u\n",
+			(meta->dataformat >>  0) & 0xff,
+			(meta->dataformat >>  8) & 0xff,
+			(meta->dataformat >> 16) & 0xff,
+			(meta->dataformat >> 24) & 0xff,
+			meta->buffersize);
+		break;
 	}
 }
 
@@ -981,6 +999,10 @@ static int check_fmt(struct file *file, enum v4l2_buf_type type)
 		if (is_sdr && is_tx && ops->vidioc_g_fmt_sdr_out)
 			return 0;
 		break;
+	case V4L2_BUF_TYPE_META_CAPTURE:
+		if (is_vid && is_rx && ops->vidioc_g_fmt_meta_cap)
+			return 0;
+		break;
 	default:
 		break;
 	}
@@ -1349,6 +1371,11 @@ static int v4l_enum_fmt(const struct v4l2_ioctl_ops *ops,
 			break;
 		ret = ops->vidioc_enum_fmt_sdr_out(file, fh, arg);
 		break;
+	case V4L2_BUF_TYPE_META_CAPTURE:
+		if (unlikely(!is_rx || !is_vid || !ops->vidioc_enum_fmt_meta_cap))
+			break;
+		ret = ops->vidioc_enum_fmt_meta_cap(file, fh, arg);
+		break;
 	}
 	if (ret == 0)
 		v4l_fill_fmtdesc(p);
@@ -1447,6 +1474,10 @@ static int v4l_g_fmt(const struct v4l2_ioctl_ops *ops,
 		if (unlikely(!is_tx || !is_sdr || !ops->vidioc_g_fmt_sdr_out))
 			break;
 		return ops->vidioc_g_fmt_sdr_out(file, fh, arg);
+	case V4L2_BUF_TYPE_META_CAPTURE:
+		if (unlikely(!is_rx || !is_vid || !ops->vidioc_g_fmt_meta_cap))
+			break;
+		return ops->vidioc_g_fmt_meta_cap(file, fh, arg);
 	}
 	return -EINVAL;
 }
@@ -1534,6 +1565,11 @@ static int v4l_s_fmt(const struct v4l2_ioctl_ops *ops,
 			break;
 		CLEAR_AFTER_FIELD(p, fmt.sdr);
 		return ops->vidioc_s_fmt_sdr_out(file, fh, arg);
+	case V4L2_BUF_TYPE_META_CAPTURE:
+		if (unlikely(!is_rx || !is_vid || !ops->vidioc_s_fmt_meta_cap))
+			break;
+		CLEAR_FROM_FIELD(p, fmt.meta.reserved);
+		return ops->vidioc_s_fmt_meta_cap(file, fh, arg);
 	}
 	return -EINVAL;
 }
@@ -1618,6 +1654,11 @@ static int v4l_try_fmt(const struct v4l2_ioctl_ops *ops,
 			break;
 		CLEAR_AFTER_FIELD(p, fmt.sdr);
 		return ops->vidioc_try_fmt_sdr_out(file, fh, arg);
+	case V4L2_BUF_TYPE_META_CAPTURE:
+		if (unlikely(!is_rx || !is_vid || !ops->vidioc_try_fmt_meta_cap))
+			break;
+		CLEAR_FROM_FIELD(p, fmt.meta.reserved);
+		return ops->vidioc_try_fmt_meta_cap(file, fh, arg);
 	}
 	return -EINVAL;
 }
diff --git a/drivers/media/v4l2-core/videobuf2-v4l2.c b/drivers/media/v4l2-core/videobuf2-v4l2.c
index 9cfbb6e4bc28..7216668d1056 100644
--- a/drivers/media/v4l2-core/videobuf2-v4l2.c
+++ b/drivers/media/v4l2-core/videobuf2-v4l2.c
@@ -575,6 +575,9 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
 	case V4L2_BUF_TYPE_SDR_OUTPUT:
 		requested_sizes[0] = f->fmt.sdr.buffersize;
 		break;
+	case V4L2_BUF_TYPE_META_CAPTURE:
+		requested_sizes[0] = f->fmt.meta.buffersize;
+		break;
 	default:
 		return -EINVAL;
 	}
diff --git a/include/media/v4l2-ioctl.h b/include/media/v4l2-ioctl.h
index 8b1d19bc9b0e..a32dcf78d4a3 100644
--- a/include/media/v4l2-ioctl.h
+++ b/include/media/v4l2-ioctl.h
@@ -43,6 +43,9 @@ struct v4l2_fh;
  * @vidioc_enum_fmt_sdr_out: pointer to the function that implements
  *	:ref:`VIDIOC_ENUM_FMT <vidioc_enum_fmt>` ioctl logic
  *	for Software Defined Radio output
+ * @vidioc_enum_fmt_meta_cap: pointer to the function that implements
+ *	:ref:`VIDIOC_ENUM_FMT <vidioc_enum_fmt>` ioctl logic
+ *	for metadata capture
  * @vidioc_g_fmt_vid_cap: pointer to the function that implements
  *	:ref:`VIDIOC_G_FMT <vidioc_g_fmt>` ioctl logic for video capture
  *	in single plane mode
@@ -73,6 +76,8 @@ struct v4l2_fh;
  * @vidioc_g_fmt_sdr_out: pointer to the function that implements
  *	:ref:`VIDIOC_G_FMT <vidioc_g_fmt>` ioctl logic for Software Defined
  *	Radio output
+ * @vidioc_g_fmt_meta_cap: pointer to the function that implements
+ *	:ref:`VIDIOC_G_FMT <vidioc_g_fmt>` ioctl logic for metadata capture
  * @vidioc_s_fmt_vid_cap: pointer to the function that implements
  *	:ref:`VIDIOC_S_FMT <vidioc_g_fmt>` ioctl logic for video capture
  *	in single plane mode
@@ -103,6 +108,8 @@ struct v4l2_fh;
  * @vidioc_s_fmt_sdr_out: pointer to the function that implements
  *	:ref:`VIDIOC_S_FMT <vidioc_g_fmt>` ioctl logic for Software Defined
  *	Radio output
+ * @vidioc_s_fmt_meta_cap: pointer to the function that implements
+ *	:ref:`VIDIOC_S_FMT <vidioc_g_fmt>` ioctl logic for metadata capture
  * @vidioc_try_fmt_vid_cap: pointer to the function that implements
  *	:ref:`VIDIOC_TRY_FMT <vidioc_g_fmt>` ioctl logic for video capture
  *	in single plane mode
@@ -135,6 +142,8 @@ struct v4l2_fh;
  * @vidioc_try_fmt_sdr_out: pointer to the function that implements
  *	:ref:`VIDIOC_TRY_FMT <vidioc_g_fmt>` ioctl logic for Software Defined
  *	Radio output
+ * @vidioc_try_fmt_meta_cap: pointer to the function that implements
+ *	:ref:`VIDIOC_TRY_FMT <vidioc_g_fmt>` ioctl logic for metadata capture
  * @vidioc_reqbufs: pointer to the function that implements
  *	:ref:`VIDIOC_REQBUFS <vidioc_reqbufs>` ioctl
  * @vidioc_querybuf: pointer to the function that implements
@@ -304,6 +313,8 @@ struct v4l2_ioctl_ops {
 					    struct v4l2_fmtdesc *f);
 	int (*vidioc_enum_fmt_sdr_out)     (struct file *file, void *fh,
 					    struct v4l2_fmtdesc *f);
+	int (*vidioc_enum_fmt_meta_cap)    (struct file *file, void *fh,
+					    struct v4l2_fmtdesc *f);
 
 	/* VIDIOC_G_FMT handlers */
 	int (*vidioc_g_fmt_vid_cap)    (struct file *file, void *fh,
@@ -330,6 +341,8 @@ struct v4l2_ioctl_ops {
 					struct v4l2_format *f);
 	int (*vidioc_g_fmt_sdr_out)    (struct file *file, void *fh,
 					struct v4l2_format *f);
+	int (*vidioc_g_fmt_meta_cap)   (struct file *file, void *fh,
+					struct v4l2_format *f);
 
 	/* VIDIOC_S_FMT handlers */
 	int (*vidioc_s_fmt_vid_cap)    (struct file *file, void *fh,
@@ -356,6 +369,8 @@ struct v4l2_ioctl_ops {
 					struct v4l2_format *f);
 	int (*vidioc_s_fmt_sdr_out)    (struct file *file, void *fh,
 					struct v4l2_format *f);
+	int (*vidioc_s_fmt_meta_cap)   (struct file *file, void *fh,
+					struct v4l2_format *f);
 
 	/* VIDIOC_TRY_FMT handlers */
 	int (*vidioc_try_fmt_vid_cap)    (struct file *file, void *fh,
@@ -382,6 +397,8 @@ struct v4l2_ioctl_ops {
 					  struct v4l2_format *f);
 	int (*vidioc_try_fmt_sdr_out)    (struct file *file, void *fh,
 					  struct v4l2_format *f);
+	int (*vidioc_try_fmt_meta_cap)   (struct file *file, void *fh,
+					  struct v4l2_format *f);
 
 	/* Buffer handlers */
 	int (*vidioc_reqbufs) (struct file *file, void *fh, struct v4l2_requestbuffers *b);
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index 724f43e69d03..d1ac0250a966 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -143,6 +143,7 @@ enum v4l2_buf_type {
 	V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE  = 10,
 	V4L2_BUF_TYPE_SDR_CAPTURE          = 11,
 	V4L2_BUF_TYPE_SDR_OUTPUT           = 12,
+	V4L2_BUF_TYPE_META_CAPTURE         = 13,
 	/* Deprecated, do not use */
 	V4L2_BUF_TYPE_PRIVATE              = 0x80,
 };
@@ -435,6 +436,7 @@ struct v4l2_capability {
 #define V4L2_CAP_SDR_CAPTURE		0x00100000  /* Is a SDR capture device */
 #define V4L2_CAP_EXT_PIX_FORMAT		0x00200000  /* Supports the extended pixel format */
 #define V4L2_CAP_SDR_OUTPUT		0x00400000  /* Is a SDR output device */
+#define V4L2_CAP_META_CAPTURE		0x00800000  /* Is a metadata capture device */
 
 #define V4L2_CAP_READWRITE              0x01000000  /* read/write systemcalls */
 #define V4L2_CAP_ASYNCIO                0x02000000  /* async I/O */
@@ -2002,6 +2004,17 @@ struct v4l2_sdr_format {
 } __attribute__ ((packed));
 
 /**
+ * struct v4l2_meta_format - metadata format definition
+ * @dataformat:		little endian four character code (fourcc)
+ * @buffersize:		maximum size in bytes required for data
+ */
+struct v4l2_meta_format {
+	__u32				dataformat;
+	__u32				buffersize;
+	__u8				reserved[24];
+} __attribute__ ((packed));
+
+/**
  * struct v4l2_format - stream data format
  * @type:	enum v4l2_buf_type; type of the data stream
  * @pix:	definition of an image format
@@ -2020,6 +2033,7 @@ struct v4l2_format {
 		struct v4l2_vbi_format		vbi;     /* V4L2_BUF_TYPE_VBI_CAPTURE */
 		struct v4l2_sliced_vbi_format	sliced;  /* V4L2_BUF_TYPE_SLICED_VBI_CAPTURE */
 		struct v4l2_sdr_format		sdr;     /* V4L2_BUF_TYPE_SDR_CAPTURE */
+		struct v4l2_meta_format		meta;    /* V4L2_BUF_TYPE_META_CAPTURE */
 		__u8	raw_data[200];                   /* user-defined */
 	} fmt;
 };
-- 
Regards,

Laurent Pinchart