[Intel-gfx] [PATCH v2 3/3] drm: Add BT.2020 constant luminance enum value for the COLOR_ENCODING property

[Ville Syrjala]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

BT.2020 specifies two YCbCr<->RGB conversion formulas. The more
traditional non-constant luminance and a more complicate constant
luminance one. Add an enum value for the constant luminance variant
as well in case someone has hardware supporting it.

v2: Reduce the enum name to fit within the 31 character uapi limit

Cc: Harry Wentland <harry.wentland at amd.com>
Cc: Daniel Vetter <daniel at ffwll.ch>
Cc: Daniel Stone <daniel at fooishbar.org>
Cc: Russell King - ARM Linux <linux at armlinux.org.uk>
Cc: Ilia Mirkin <imirkin at alum.mit.edu>
Cc: Hans Verkuil <hverkuil at xs4all.nl>
CC: Uma Shankar <uma.shankar at intel.com>
Cc: Shashank Sharma <shashank.sharma at intel.com>
Cc: Jyri Sarha <jsarha at ti.com>
Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
Acked-by: Harry Wentland <harry.wentland at amd.com> #v1
---
 drivers/gpu/drm/drm_color_mgmt.c | 1 +
 include/drm/drm_color_mgmt.h     | 3 ++-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_color_mgmt.c b/drivers/gpu/drm/drm_color_mgmt.c
index 4ff064623836..cc28c32399af 100644
--- a/drivers/gpu/drm/drm_color_mgmt.c
+++ b/drivers/gpu/drm/drm_color_mgmt.c
@@ -358,6 +358,7 @@ static const char * const color_encoding_name[] = {
 	[DRM_COLOR_YCBCR_BT601] = "ITU-R BT.601 YCbCr",
 	[DRM_COLOR_YCBCR_BT709] = "ITU-R BT.709 YCbCr",
 	[DRM_COLOR_YCBCR_BT2020] = "ITU-R BT.2020 YCbCr",
+	[DRM_COLOR_YCBCR_BT2020_CONST] = "ITU-R BT.2020 YCbCr const",
 };
 
 static const char * const color_range_name[] = {
diff --git a/include/drm/drm_color_mgmt.h b/include/drm/drm_color_mgmt.h
index b3b6d302ca8c..175943c87d5b 100644
--- a/include/drm/drm_color_mgmt.h
+++ b/include/drm/drm_color_mgmt.h
@@ -41,7 +41,8 @@ int drm_mode_crtc_set_gamma_size(struct drm_crtc *crtc,
 enum drm_color_encoding {
 	DRM_COLOR_YCBCR_BT601,
 	DRM_COLOR_YCBCR_BT709,
-	DRM_COLOR_YCBCR_BT2020,
+	DRM_COLOR_YCBCR_BT2020, /* non-constant luminance */
+	DRM_COLOR_YCBCR_BT2020_CONST, /* constant luminance */
 	DRM_COLOR_ENCODING_MAX,
 };
 
-- 
2.13.6