[PATCH v3 4/5] media: v4l2-ctrl: Add jpeg enc exif mode control

[Xia Jiang]

Add jpeg enc CID definition for exif mode control.

Signed-off-by: Xia Jiang <xia.jiang@xxxxxxxxxxxx>
---
v3: new add patch for V4L2_CID_JPEG_ENABLE_EXIF
---
 Documentation/media/uapi/v4l/ext-ctrls-jpeg.rst | 10 ++++++++++
 drivers/media/v4l2-core/v4l2-ctrls.c            |  1 +
 include/uapi/linux/v4l2-controls.h              |  2 ++
 3 files changed, 13 insertions(+)

diff --git a/Documentation/media/uapi/v4l/ext-ctrls-jpeg.rst b/Documentation/media/uapi/v4l/ext-ctrls-jpeg.rst
index 60ce3f949319..d44a539e2eb4 100644
--- a/Documentation/media/uapi/v4l/ext-ctrls-jpeg.rst
+++ b/Documentation/media/uapi/v4l/ext-ctrls-jpeg.rst
@@ -109,5 +109,15 @@ JPEG Control IDs
 
 
 
+``V4L2_CID_JPEG_ENABLE_EXIF (integer)``
+    ``V4L2_CID_JPEG_ENABLE_EXIF (integer)`` control determines JPEG
+    encoder mode. Its value of 0 means JPEG mode, 1 means EXIF mode. If
+    EXIF mode is enabled, the JPEG encoder will not write out SOI marker
+    (start from 0xffd8) but write out from DQT marker(start from
+    0xffdb). Software program can fill the EXIF content above the DQT
+    marker to finish one EXIF JPEG.
+
+
+
 For more details about JPEG specification, refer to :ref:`itu-t81`,
 :ref:`jfif`, :ref:`w3c-jpeg-jfif`.
diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
index 371537dd8cd3..c96c10480ebd 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls.c
@@ -1025,6 +1025,7 @@ const char *v4l2_ctrl_get_name(u32 id)
 	case V4L2_CID_JPEG_RESTART_INTERVAL:	return "Restart Interval";
 	case V4L2_CID_JPEG_COMPRESSION_QUALITY:	return "Compression Quality";
 	case V4L2_CID_JPEG_ACTIVE_MARKER:	return "Active Markers";
+	case V4L2_CID_JPEG_ENABLE_EXIF:		return "Enable Exif";
 
 	/* Image source controls */
 	/* Keep the order of the 'case's the same as in v4l2-controls.h! */
diff --git a/include/uapi/linux/v4l2-controls.h b/include/uapi/linux/v4l2-controls.h
index a2669b79b294..da619f43de65 100644
--- a/include/uapi/linux/v4l2-controls.h
+++ b/include/uapi/linux/v4l2-controls.h
@@ -1022,6 +1022,8 @@ enum v4l2_jpeg_chroma_subsampling {
 #define	V4L2_JPEG_ACTIVE_MARKER_DQT		(1 << 17)
 #define	V4L2_JPEG_ACTIVE_MARKER_DHT		(1 << 18)
 
+#define	V4L2_CID_JPEG_ENABLE_EXIF		(V4L2_CID_JPEG_CLASS_BASE + 5)
+
 
 /* Image source controls */
 #define V4L2_CID_IMAGE_SOURCE_CLASS_BASE	(V4L2_CTRL_CLASS_IMAGE_SOURCE | 0x900)
-- 
2.18.0