drm/fourcc: Add DRM_FORMAT_R[124]

Introduce fourcc codes for single-channel frame buffer formats with two, four, and sixteen brightness levels, where there is a direct relationship between channel value and brightness. As the number of bits per pixel is less than eight, these rely on proper block handling for the calculation of bits per pixel and pitch. The fill order (the order in which multiple pixels are packed in a byte) is the same order as used for grayscale (2, 4, and 16 levels) images in the PNG specification, Version 1.2. This order is also the recommended and default order (FillOrder = 1) for bilevel and grayscale (16 levels) images in the TIFF 6.0 Specification, and is also used for monochrome images in the PBM file format, monochrome Linux frame buffer logos, and BDF and PSF (Linux kernel) font files.

Geert Uytterhoeven committed 4 years ago

Commit d0931001 parent 8aba4d32 files · +15 −0Browse files

Unified · Split

2 files

drivers/gpu/drm/drm_fourcc.c +6 −0
include/uapi/drm/drm_fourcc.h +9 −0

drivers/gpu/drm/drm_fourcc.c+6−0

@@ -154,6 +154,12 @@ const struct drm_format_info *__drm_format_info(u32 format) · 153 unmodified lines
154	154	{ .format = DRM_FORMAT_C4, .depth = 4, .num_planes = 1,
155	155	.char_per_block = { 1, }, .block_w = { 2, }, .block_h = { 1, }, .hsub = 1, .vsub = 1, .is_color_indexed = true },
156	156	{ .format = DRM_FORMAT_C8, .depth = 8, .num_planes = 1, .cpp = { 1, 0, 0 }, .hsub = 1, .vsub = 1, .is_color_indexed = true },
	157	+ { .format = DRM_FORMAT_R1, .depth = 1, .num_planes = 1,
	158	+ .char_per_block = { 1, }, .block_w = { 8, }, .block_h = { 1, }, .hsub = 1, .vsub = 1 },
	159	+ { .format = DRM_FORMAT_R2, .depth = 2, .num_planes = 1,
	160	+ .char_per_block = { 1, }, .block_w = { 4, }, .block_h = { 1, }, .hsub = 1, .vsub = 1 },
	161	+ { .format = DRM_FORMAT_R4, .depth = 4, .num_planes = 1,
	162	+ .char_per_block = { 1, }, .block_w = { 2, }, .block_h = { 1, }, .hsub = 1, .vsub = 1 },
157	163	{ .format = DRM_FORMAT_R8, .depth = 8, .num_planes = 1, .cpp = { 1, 0, 0 }, .hsub = 1, .vsub = 1 },
158	164	{ .format = DRM_FORMAT_R10, .depth = 10, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1 },
159	165	{ .format = DRM_FORMAT_R12, .depth = 12, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1 },

include/uapi/drm/drm_fourcc.h+9−0

@@ -104,6 +104,15 @@ extern "C" { · 103 unmodified lines
104	104	#define DRM_FORMAT_C4 fourcc_code('C', '4', ' ', ' ') /* [7:0] C0:C1 4:4 two pixels/byte */
105	105	#define DRM_FORMAT_C8 fourcc_code('C', '8', ' ', ' ') /* [7:0] C */
106	106
	107	+/* 1 bpp Red (direct relationship between channel value and brightness) */
	108	+#define DRM_FORMAT_R1 fourcc_code('R', '1', ' ', ' ') /* [7:0] R0:R1:R2:R3:R4:R5:R6:R7 1:1:1:1:1:1:1:1 eight pixels/byte */
	109	+
	110	+/* 2 bpp Red (direct relationship between channel value and brightness) */
	111	+#define DRM_FORMAT_R2 fourcc_code('R', '2', ' ', ' ') /* [7:0] R0:R1:R2:R3 2:2:2:2 four pixels/byte */
	112	+
	113	+/* 4 bpp Red (direct relationship between channel value and brightness) */
	114	+#define DRM_FORMAT_R4 fourcc_code('R', '4', ' ', ' ') /* [7:0] R0:R1 4:4 two pixels/byte */
	115	+
107	116	/* 8 bpp Red (direct relationship between channel value and brightness) */
108	117	#define DRM_FORMAT_R8 fourcc_code('R', '8', ' ', ' ') /* [7:0] R */
109	118