Hi Sakari,
On 03.02.2025 10:58, Sakari Ailus wrote:
Add a bitmask control (V4L2_CID_COLOUR_PATTERN_FLIP) to tell whether
flipping results in a change in the sensor's colour pattern, separately
horizontally and vertically. The information is essential for raw formats
when using generic raw mbus codes.
Is this control really necessary? Are there cases when V4L2_CID_HFLIP
or/and V4L2_CID_VFLIP is enabled and the CFA pattern does not change?
Could a raw sensor driver be capable of reporting the
V4L2_CID_COLOUR_PATTERN based on current values of the HFLIP/VFLIP? I'm
not sure I understood all the aspects of patch #7 (V4L2_CID_COLOUR_PATTERN).
Regards,
Mirela
Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
---
.../media/v4l/ext-ctrls-image-source.rst | 8 ++++++++
drivers/media/v4l2-core/v4l2-ctrls-defs.c | 2 ++
include/uapi/linux/v4l2-controls.h | 15 +++++++++++++++
3 files changed, 25 insertions(+)
diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-image-source.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-image-source.rst
index fca729512b6f..ecfa38c118e3 100644
--- a/Documentation/userspace-api/media/v4l/ext-ctrls-image-source.rst
+++ b/Documentation/userspace-api/media/v4l/ext-ctrls-image-source.rst
@@ -102,3 +102,11 @@ Image Source Control IDs
This control may only be used on a V4L2 sub-device.
This is a read-only control.
+
+``V4L2_CID_COLOUR_PATTERN_FLIP (bitmask)``
+ Whether the horizontal or vertical flipping controls (V4L2_CID_HFLIP and
+ V4L2_CID_VFLIP) have an effect on the pixel order of the output colour
+ pattern. Macros ``V4L2_COLOUR_PATTERN_FLIP_HORIZONTAL`` and
+ ``V4L2_COLOUR_PATTERN_FLIP_VERTICAL`` define bitmasks for both bits. If
+ either horizontal or vertical bit is set, the readout pattern order is that
+ of the reversed readout.
diff --git a/drivers/media/v4l2-core/v4l2-ctrls-defs.c b/drivers/media/v4l2-core/v4l2-ctrls-defs.c
index 5b6a4a94f18f..3f0704a982b8 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls-defs.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls-defs.c
@@ -1156,6 +1156,7 @@ const char *v4l2_ctrl_get_name(u32 id)
case V4L2_CID_TEST_PATTERN_GREENB: return "Green (Blue) Pixel Value";
case V4L2_CID_NOTIFY_GAINS: return "Notify Gains";
case V4L2_CID_COLOUR_PATTERN: return "Colour Pattern";
+ case V4L2_CID_COLOUR_PATTERN_FLIP: return "Colour Pattern Flip";
/* Image processing controls */
/* Keep the order of the 'case's the same as in v4l2-controls.h! */
@@ -1474,6 +1475,7 @@ void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
*max = 0xffff;
break;
case V4L2_CID_FLASH_FAULT:
+ case V4L2_CID_COLOUR_PATTERN_FLIP:
case V4L2_CID_JPEG_ACTIVE_MARKER:
case V4L2_CID_3A_LOCK:
case V4L2_CID_AUTO_FOCUS_STATUS:
diff --git a/include/uapi/linux/v4l2-controls.h b/include/uapi/linux/v4l2-controls.h
index 8e761c38b995..fd6465e9a743 100644
--- a/include/uapi/linux/v4l2-controls.h
+++ b/include/uapi/linux/v4l2-controls.h
@@ -1215,11 +1215,26 @@ enum v4l2_jpeg_chroma_subsampling {
#define V4L2_CID_NOTIFY_GAINS (V4L2_CID_IMAGE_SOURCE_CLASS_BASE + 9)
#define V4L2_CID_COLOUR_PATTERN (V4L2_CID_IMAGE_SOURCE_CLASS_BASE + 10)
+/*
+ * CFA pattern start shall be aligned with the number of patterns for colour
+ * components. Patterns shall be calculable based on flipping when it affects
+ * the pattern the following way:
+ *
+ * flipped_pattern = native_pattern ^
+ * ((hflip ? V4L2_COLOUR_PATTERN_FLIP_HORIZONTAL : 0) |
+ * (vflip ? V4L2_COLOUR_PATTERN_FLIP_VERTICAL : 0))
+ *
+ * where hflip and vflip are the values of V4L2_CID_HFLIP and V4L2_CID_VFLIP
+ * controls, respectively.
+ */
#define V4L2_COLOUR_PATTERN_GRBG 0
#define V4L2_COLOUR_PATTERN_RGGB 1
#define V4L2_COLOUR_PATTERN_BGGR 2
#define V4L2_COLOUR_PATTERN_GBRG 3
+#define V4L2_CID_COLOUR_PATTERN_FLIP (V4L2_CID_IMAGE_SOURCE_CLASS_BASE + 11)
+#define V4L2_COLOUR_PATTERN_FLIP_HORIZONTAL (1U << 0)
+#define V4L2_COLOUR_PATTERN_FLIP_VERTICAL (1U << 1)
/* Image processing controls */
--
2.39.5
