Add greyscale Y8 format. The 8-bit greyscale format has been discussed before, and the earlier guidance was to use DRM_FORMAT_R8, as a single-channel 8-bit pixel.
However, adding DRM_FORMAT_Y8 makes sense, we can mark it as 'is_yuv' in the drm_format_info, and this can help the drivers handle e.g. full/limited range. This will distinguish two single-channel formats: R8, which is a RGB format with the same value for all components, and Y8, which is a Y-only YCbCr format, with Cb and Cr being neutral. Acked-by: Dmitry Baryshkov <[email protected]> Reviewed-by: Pekka Paalanen <[email protected]> Reviewed-by: Vishal Sagar <[email protected]> Signed-off-by: Tomi Valkeinen <[email protected]> --- drivers/gpu/drm/drm_fourcc.c | 1 + include/uapi/drm/drm_fourcc.h | 9 +++++++++ 2 files changed, 10 insertions(+) diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c index b22ef86428a1..a39b9d7a5b62 100644 --- a/drivers/gpu/drm/drm_fourcc.c +++ b/drivers/gpu/drm/drm_fourcc.c @@ -275,6 +275,7 @@ const struct drm_format_info *__drm_format_info(u32 format) { .format = DRM_FORMAT_YVU422, .depth = 0, .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 2, .vsub = 1, .is_yuv = true }, { .format = DRM_FORMAT_YUV444, .depth = 0, .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 1, .vsub = 1, .is_yuv = true }, { .format = DRM_FORMAT_YVU444, .depth = 0, .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 1, .vsub = 1, .is_yuv = true }, + { .format = DRM_FORMAT_Y8, .depth = 8, .num_planes = 1, .cpp = { 1, 0, 0 }, .hsub = 1, .vsub = 1, .is_yuv = true }, { .format = DRM_FORMAT_NV12, .depth = 0, .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 2, .vsub = 2, .is_yuv = true }, { .format = DRM_FORMAT_NV21, .depth = 0, .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 2, .vsub = 2, .is_yuv = true }, { .format = DRM_FORMAT_NV16, .depth = 0, .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 2, .vsub = 1, .is_yuv = true }, diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h index 6c786701238e..e4451668499a 100644 --- a/include/uapi/drm/drm_fourcc.h +++ b/include/uapi/drm/drm_fourcc.h @@ -459,6 +459,15 @@ extern "C" { #define DRM_FORMAT_YUV444 fourcc_code('Y', 'U', '2', '4') /* non-subsampled Cb (1) and Cr (2) planes */ #define DRM_FORMAT_YVU444 fourcc_code('Y', 'V', '2', '4') /* non-subsampled Cr (1) and Cb (2) planes */ +/* + * Y-only (greyscale) formats + * + * The Y-only formats are handled similarly to the YCbCr formats in the display + * pipeline, with the Cb and Cr implicitly neutral (0.0 in nominal values). This + * also means that COLOR_RANGE property applies to the Y-only formats. + */ + +#define DRM_FORMAT_Y8 fourcc_code('G', 'R', 'E', 'Y') /* 8-bit Y-only */ /* * Format Modifiers: -- 2.43.0
