[PATCH RESEND v2 07/32] drm/blend: Get a rotation name from it's bitfield

Louis Chauvet
2025-10-29T14:37:04Z

Having the rotation/reflection name from its value can be useful for
debugging purpose. Extract the rotation property table and implement
drm_get_rotation_name.

Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
drivers/gpu/drm/drm_blend.c | 35 ++++++++++++++++++++++++++---------
include/drm/drm_blend.h | 2 ++
2 files changed, 28 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/drm_blend.c b/drivers/gpu/drm/drm_blend.c
index 6852d73c931c..bc7c05e20242 100644
--- a/drivers/gpu/drm/drm_blend.c
+++ b/drivers/gpu/drm/drm_blend.c
@@ -241,6 +241,31 @@ int drm_plane_create_alpha_property(struct drm_plane *plane)
}
EXPORT_SYMBOL(drm_plane_create_alpha_property);

+static const struct drm_prop_enum_list rotation_props[] = {
+ { __builtin_ffs(DRM_MODE_ROTATE_0) - 1, "rotate-0" },
+ { __builtin_ffs(DRM_MODE_ROTATE_90) - 1, "rotate-90" },
+ { __builtin_ffs(DRM_MODE_ROTATE_180) - 1, "rotate-180" },
+ { __builtin_ffs(DRM_MODE_ROTATE_270) - 1, "rotate-270" },
+ { __builtin_ffs(DRM_MODE_REFLECT_X) - 1, "reflect-x" },
+ { __builtin_ffs(DRM_MODE_REFLECT_Y) - 1, "reflect-y" },
+};
+
+/**
+ * drm_get_rotation_name - Return the name of a rotation
+ * @rotation: The rotation mask (DRM_MODE_ROTATE_* | DRM_MODE_REFLECT_*)
+ *
+ * Returns: the name of the rotation type (unknown) if rotation is not
+ * a known rotation/reflection
+ */
+const char *drm_get_rotation_name(unsigned int rotation)
+{
+ if (rotation < ARRAY_SIZE(rotation_props))
+ return rotation_props[rotation].name;
+
+ return "(unknown)";
+}
+EXPORT_SYMBOL(drm_get_rotation_name);
+
/**
* drm_plane_create_rotation_property - create a new rotation property
* @plane: drm plane
@@ -279,14 +304,6 @@ int drm_plane_create_rotation_property(struct drm_plane *plane,
unsigned int rotation,
unsigned int supported_rotations)
{
- static const struct drm_prop_enum_list props[] = {
- { __builtin_ffs(DRM_MODE_ROTATE_0) - 1, "rotate-0" },
- { __builtin_ffs(DRM_MODE_ROTATE_90) - 1, "rotate-90" },
- { __builtin_ffs(DRM_MODE_ROTATE_180) - 1, "rotate-180" },
- { __builtin_ffs(DRM_MODE_ROTATE_270) - 1, "rotate-270" },
- { __builtin_ffs(DRM_MODE_REFLECT_X) - 1, "reflect-x" },
- { __builtin_ffs(DRM_MODE_REFLECT_Y) - 1, "reflect-y" },
- };
struct drm_property *prop;

WARN_ON((supported_rotations & DRM_MODE_ROTATE_MASK) == 0);
@@ -294,7 +311,7 @@ int drm_plane_create_rotation_property(struct drm_plane *plane,
WARN_ON(rotation & ~supported_rotations);

prop = drm_property_create_bitmask(plane->dev, 0, "rotation",
- props, ARRAY_SIZE(props),
+ rotation_props, ARRAY_SIZE(rotation_props),
supported_rotations);
if (!prop)
return -ENOMEM;
diff --git a/include/drm/drm_blend.h b/include/drm/drm_blend.h
index 88bdfec3bd88..381d1f8d815b 100644
--- a/include/drm/drm_blend.h
+++ b/include/drm/drm_blend.h
@@ -42,6 +42,8 @@ static inline bool drm_rotation_90_or_270(unsigned int rotation)

#define DRM_BLEND_ALPHA_OPAQUE 0xffff

+const char *drm_get_rotation_name(unsigned int rotation);
+
int drm_plane_create_alpha_property(struct drm_plane *plane);
int drm_plane_create_rotation_property(struct drm_plane *plane,
unsigned int rotation,

--
2.51.0