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drm/fourcc: Add DRM_FORMAT_D[1248]

As Rn covers single-channel formats with a direct relationship between channel value and brightness, and Cn can be any colors, there are currently no fourcc codes to describe single-channel formats with an inverse relationship between channel value and brightness. Introduce fourcc codes for a single-channel frame buffer format with two, four, sixteen, or 256 brightness ("darkness") levels, where there is an inverse relationship between channel value and brightness. As the number of bits per pixel may be less than eight, some of these formats 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 b92db7e1 parent d0931002 files · +19 −0Browse files

Unified · Split

2 files
  1. drivers/gpu/drm/drm_fourcc.c +7 −0
  2. include/uapi/drm/drm_fourcc.h +12 −0
drivers/gpu/drm/drm_fourcc.c+7−0
@@ -154,6 +154,13 @@ const struct drm_format_info *__drm_format_info(u32 format) · 153 unmodified lines
154 { .format = DRM_FORMAT_C4, .depth = 4, .num_planes = 1,154 { .format = DRM_FORMAT_C4, .depth = 4, .num_planes = 1,
155 .char_per_block = { 1, }, .block_w = { 2, }, .block_h = { 1, }, .hsub = 1, .vsub = 1, .is_color_indexed = true },155 .char_per_block = { 1, }, .block_w = { 2, }, .block_h = { 1, }, .hsub = 1, .vsub = 1, .is_color_indexed = true },
156 { .format = DRM_FORMAT_C8, .depth = 8, .num_planes = 1, .cpp = { 1, 0, 0 }, .hsub = 1, .vsub = 1, .is_color_indexed = true },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_D1, .depth = 1, .num_planes = 1,
158 .char_per_block = { 1, }, .block_w = { 8, }, .block_h = { 1, }, .hsub = 1, .vsub = 1 },
159 { .format = DRM_FORMAT_D2, .depth = 2, .num_planes = 1,
160 .char_per_block = { 1, }, .block_w = { 4, }, .block_h = { 1, }, .hsub = 1, .vsub = 1 },
161 { .format = DRM_FORMAT_D4, .depth = 4, .num_planes = 1,
162 .char_per_block = { 1, }, .block_w = { 2, }, .block_h = { 1, }, .hsub = 1, .vsub = 1 },
163 { .format = DRM_FORMAT_D8, .depth = 8, .num_planes = 1, .cpp = { 1, 0, 0 }, .hsub = 1, .vsub = 1 },
157 { .format = DRM_FORMAT_R1, .depth = 1, .num_planes = 1,164 { .format = DRM_FORMAT_R1, .depth = 1, .num_planes = 1,
158 .char_per_block = { 1, }, .block_w = { 8, }, .block_h = { 1, }, .hsub = 1, .vsub = 1 },165 .char_per_block = { 1, }, .block_w = { 8, }, .block_h = { 1, }, .hsub = 1, .vsub = 1 },
159 { .format = DRM_FORMAT_R2, .depth = 2, .num_planes = 1,166 { .format = DRM_FORMAT_R2, .depth = 2, .num_planes = 1,
include/uapi/drm/drm_fourcc.h+12−0
@@ -104,6 +104,18 @@ extern "C" { · 103 unmodified lines
104#define DRM_FORMAT_C4 fourcc_code('C', '4', ' ', ' ') /* [7:0] C0:C1 4:4 two pixels/byte */104#define DRM_FORMAT_C4 fourcc_code('C', '4', ' ', ' ') /* [7:0] C0:C1 4:4 two pixels/byte */
105#define DRM_FORMAT_C8 fourcc_code('C', '8', ' ', ' ') /* [7:0] C */105#define DRM_FORMAT_C8 fourcc_code('C', '8', ' ', ' ') /* [7:0] C */
106 106
107/* 1 bpp Darkness (inverse relationship between channel value and brightness) */
108#define DRM_FORMAT_D1 fourcc_code('D', '1', ' ', ' ') /* [7:0] D0:D1:D2:D3:D4:D5:D6:D7 1:1:1:1:1:1:1:1 eight pixels/byte */
109
110/* 2 bpp Darkness (inverse relationship between channel value and brightness) */
111#define DRM_FORMAT_D2 fourcc_code('D', '2', ' ', ' ') /* [7:0] D0:D1:D2:D3 2:2:2:2 four pixels/byte */
112
113/* 4 bpp Darkness (inverse relationship between channel value and brightness) */
114#define DRM_FORMAT_D4 fourcc_code('D', '4', ' ', ' ') /* [7:0] D0:D1 4:4 two pixels/byte */
115
116/* 8 bpp Darkness (inverse relationship between channel value and brightness) */
117#define DRM_FORMAT_D8 fourcc_code('D', '8', ' ', ' ') /* [7:0] D */
118
107/* 1 bpp Red (direct relationship between channel value and brightness) */119/* 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 */120#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 */
109 121