[RFC v5 12/15] media: uapi: Documentation: Use luma formats with CFA pattern control

Sakari Ailus
2025-02-03T08:59:53Z

Document that the luma-only, greyscale formats (Y10 etc.) are used also
for non-greyscale images with the CFA pattern specified by the
V4L2_CID_COLOUR_PATTERN control.

The advantage of this approach is that there is little (or none at all)
work needed to be able to capture such images with existing CSI-2 receiver
drivers as many already support greyscale formats when compared to new
CFA-agnostic pixelformats.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
---
Documentation/userspace-api/media/v4l/pixfmt-yuv-luma.rst | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/Documentation/userspace-api/media/v4l/pixfmt-yuv-luma.rst b/Documentation/userspace-api/media/v4l/pixfmt-yuv-luma.rst
index 74df19be91f6..ae4e431b5fd9 100644
--- a/Documentation/userspace-api/media/v4l/pixfmt-yuv-luma.rst
+++ b/Documentation/userspace-api/media/v4l/pixfmt-yuv-luma.rst
@@ -9,6 +9,11 @@ Luma-Only Formats
This family of formats only store the luma component of a Y'CbCr image. They
are often referred to as greyscale formats.

+These pixel formats are also used on :term:`MC-centric` devices when the CFA
+pattern is specified by the :ref:`V4L2_CID_COLOUR_PATTERN
+<image-source-control-colour-pattern>` control in the image source, typically a
+camera sensor.
+
.. note::

- In all the tables that follow, bit 7 is the most significant bit in a byte.
--
2.39.5