[PATCH v5 1/3] media: videodev2: Add flag to unconditionnaly enumerate pixels formats

[Benjamin Gaignard]

When the index field is ORed with V4L2_FMT_FLAG_ENUM_ALL the driver
will ignore any configuration and enumerate all the possible formats.
Drivers which do not support this flag yet always return an EINVAL
error code.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard at collabora.com>
---
changes in version 5:
- Reset the proposal to follow Hans's advices
- Add new flag to be used with index field.

 .../userspace-api/media/v4l/vidioc-enum-fmt.rst      | 12 +++++++++++-
 .../userspace-api/media/videodev2.h.rst.exceptions   |  1 +
 include/uapi/linux/videodev2.h                       |  3 +++
 3 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/Documentation/userspace-api/media/v4l/vidioc-enum-fmt.rst b/Documentation/userspace-api/media/v4l/vidioc-enum-fmt.rst
index 3adb3d205531..12e1e65e6a71 100644
--- a/Documentation/userspace-api/media/v4l/vidioc-enum-fmt.rst
+++ b/Documentation/userspace-api/media/v4l/vidioc-enum-fmt.rst
@@ -85,7 +85,11 @@ the ``mbus_code`` field is handled differently:
     * - __u32
       - ``index``
       - Number of the format in the enumeration, set by the application.
-	This is in no way related to the ``pixelformat`` field.
+        This is in no way related to the ``pixelformat`` field. When the
+        index is ORed with V4L2_FMT_FLAG_ENUM_ALL the driver will ignore
+        any configuration and enumerate all the possible formats. Drivers
+        which do not support this flag yet always return an ``EINVAL``
+        error code.
     * - __u32
       - ``type``
       - Type of the data stream, set by the application. Only these types
@@ -234,6 +238,12 @@ the ``mbus_code`` field is handled differently:
 	valid. The buffer consists of ``height`` lines, each having ``width``
 	Data Units of data and the offset (in bytes) between the beginning of
 	each two consecutive lines is ``bytesperline``.
+    * - ``V4L2_FMT_FLAG_ENUM_ALL``
+      - 0x80000000
+      - When the applications ORs ``index`` with ``V4L2_FMT_FLAG_ENUM_ALL`` flag
+        the driver enumerates all the possible pixel formats without taking care
+        of any already set configuration. Drivers which do not support this flag
+        yet always return ``EINVAL``.
 
 Return Value
 ============
diff --git a/Documentation/userspace-api/media/videodev2.h.rst.exceptions b/Documentation/userspace-api/media/videodev2.h.rst.exceptions
index bdc628e8c1d6..8dc10a500fc6 100644
--- a/Documentation/userspace-api/media/videodev2.h.rst.exceptions
+++ b/Documentation/userspace-api/media/videodev2.h.rst.exceptions
@@ -216,6 +216,7 @@ replace define V4L2_FMT_FLAG_CSC_YCBCR_ENC fmtdesc-flags
 replace define V4L2_FMT_FLAG_CSC_HSV_ENC fmtdesc-flags
 replace define V4L2_FMT_FLAG_CSC_QUANTIZATION fmtdesc-flags
 replace define V4L2_FMT_FLAG_META_LINE_BASED fmtdesc-flags
+replace define V4L2_FMT_FLAG_ENUM_ALL fmtdesc-flags
 
 # V4L2 timecode types
 replace define V4L2_TC_TYPE_24FPS timecode-type
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index 4e91362da6da..3d11f91273a1 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -904,6 +904,9 @@ struct v4l2_fmtdesc {
 #define V4L2_FMT_FLAG_CSC_QUANTIZATION		0x0100
 #define V4L2_FMT_FLAG_META_LINE_BASED		0x0200
 
+/*  Format description flag, to be ORed with the index */
+#define V4L2_FMT_FLAG_ENUM_ALL			0x80000000
+
 	/* Frame Size and frame rate enumeration */
 /*
  *	F R A M E   S I Z E   E N U M E R A T I O N
-- 
2.43.0