1/* SPDX-License-Identifier: GPL-2.0 or MIT */
2
3#ifndef DRM_FORMAT_INTERNAL_H
4#define DRM_FORMAT_INTERNAL_H
5
6#include <linux/bits.h>
7#include <linux/types.h>
8#include <linux/swab.h>
9
10/*
11 * Each pixel-format conversion helper takes a raw pixel in a
12 * specific input format and returns a raw pixel in a specific
13 * output format. All pixels are in little-endian byte order.
14 *
15 * Function names are
16 *
17 * drm_pixel_<input>_to_<output>_<algorithm>()
18 *
19 * where <input> and <output> refer to pixel formats. The
20 * <algorithm> is optional and hints to the method used for the
21 * conversion. Helpers with no algorithm given apply pixel-bit
22 * shifting.
23 *
24 * The argument type is u32. We expect this to be wide enough to
25 * hold all conversion input from 32-bit RGB to any output format.
26 * The Linux kernel should avoid format conversion for anything
27 * but XRGB8888 input data. Converting from other format can still
28 * be acceptable in some cases.
29 *
30 * The return type is u32. It is wide enough to hold all conversion
31 * output from XRGB8888. For output formats wider than 32 bit, a
32 * return type of u64 would be acceptable.
33 */
34
35/*
36 * Conversions from XRGB8888
37 */
38
39static inline u32 drm_pixel_xrgb8888_to_r8_bt601(u32 pix)
40{
41 u32 r = (pix & 0x00ff0000) >> 16;
42 u32 g = (pix & 0x0000ff00) >> 8;
43 u32 b = pix & 0x000000ff;
44
45 /* ITU-R BT.601: Y = 0.299 R + 0.587 G + 0.114 B */
46 return (77 * r + 150 * g + 29 * b) / 256;
47}
48
49static inline u32 drm_pixel_xrgb8888_to_rgb332(u32 pix)
50{
51 return ((pix & 0x00e00000) >> 16) |
52 ((pix & 0x0000e000) >> 11) |
53 ((pix & 0x000000c0) >> 6);
54}
55
56static inline u32 drm_pixel_xrgb8888_to_rgb565(u32 pix)
57{
58 return ((pix & 0x00f80000) >> 8) |
59 ((pix & 0x0000fc00) >> 5) |
60 ((pix & 0x000000f8) >> 3);
61}
62
63static inline u32 drm_pixel_xrgb8888_to_rgb565be(u32 pix)
64{
65 return swab16(drm_pixel_xrgb8888_to_rgb565(pix));
66}
67
68static inline u32 drm_pixel_xrgb8888_to_rgbx5551(u32 pix)
69{
70 return ((pix & 0x00f80000) >> 8) |
71 ((pix & 0x0000f800) >> 5) |
72 ((pix & 0x000000f8) >> 2);
73}
74
75static inline u32 drm_pixel_xrgb8888_to_rgba5551(u32 pix)
76{
77 return drm_pixel_xrgb8888_to_rgbx5551(pix) |
78 BIT(0); /* set alpha bit */
79}
80
81static inline u32 drm_pixel_xrgb8888_to_xrgb1555(u32 pix)
82{
83 return ((pix & 0x00f80000) >> 9) |
84 ((pix & 0x0000f800) >> 6) |
85 ((pix & 0x000000f8) >> 3);
86}
87
88static inline u32 drm_pixel_xrgb8888_to_argb1555(u32 pix)
89{
90 return BIT(15) | /* set alpha bit */
91 drm_pixel_xrgb8888_to_xrgb1555(pix);
92}
93
94static inline u32 drm_pixel_xrgb8888_to_rgb888(u32 pix)
95{
96 return pix & GENMASK(23, 0);
97}
98
99static inline u32 drm_pixel_xrgb8888_to_bgr888(u32 pix)
100{
101 return ((pix & 0x00ff0000) >> 16) |
102 ((pix & 0x0000ff00)) |
103 ((pix & 0x000000ff) << 16);
104}
105
106static inline u32 drm_pixel_xrgb8888_to_argb8888(u32 pix)
107{
108 return GENMASK(31, 24) | /* fill alpha bits */
109 pix;
110}
111
112static inline u32 drm_pixel_xrgb8888_to_xbgr8888(u32 pix)
113{
114 return ((pix & 0xff000000)) | /* also copy filler bits */
115 ((pix & 0x00ff0000) >> 16) |
116 ((pix & 0x0000ff00)) |
117 ((pix & 0x000000ff) << 16);
118}
119
120static inline u32 drm_pixel_xrgb8888_to_bgrx8888(u32 pix)
121{
122 return ((pix & 0xff000000) >> 24) | /* also copy filler bits */
123 ((pix & 0x00ff0000) >> 8) |
124 ((pix & 0x0000ff00) << 8) |
125 ((pix & 0x000000ff) << 24);
126}
127
128static inline u32 drm_pixel_xrgb8888_to_abgr8888(u32 pix)
129{
130 return GENMASK(31, 24) | /* fill alpha bits */
131 drm_pixel_xrgb8888_to_xbgr8888(pix);
132}
133
134static inline u32 drm_pixel_xrgb8888_to_xrgb2101010(u32 pix)
135{
136 pix = ((pix & 0x000000ff) << 2) |
137 ((pix & 0x0000ff00) << 4) |
138 ((pix & 0x00ff0000) << 6);
139 return pix | ((pix >> 8) & 0x00300c03);
140}
141
142static inline u32 drm_pixel_xrgb8888_to_argb2101010(u32 pix)
143{
144 return GENMASK(31, 30) | /* set alpha bits */
145 drm_pixel_xrgb8888_to_xrgb2101010(pix);
146}
147
148static inline u32 drm_pixel_xrgb8888_to_xbgr2101010(u32 pix)
149{
150 pix = ((pix & 0x00ff0000) >> 14) |
151 ((pix & 0x0000ff00) << 4) |
152 ((pix & 0x000000ff) << 22);
153 return pix | ((pix >> 8) & 0x00300c03);
154}
155
156static inline u32 drm_pixel_xrgb8888_to_abgr2101010(u32 pix)
157{
158 return GENMASK(31, 30) | /* set alpha bits */
159 drm_pixel_xrgb8888_to_xbgr2101010(pix);
160}
161
162/*
163 * Conversion from ARGB8888
164 */
165
166static inline u32 drm_pixel_argb8888_to_argb4444(u32 pix)
167{
168 return ((pix & 0xf0000000) >> 16) |
169 ((pix & 0x00f00000) >> 12) |
170 ((pix & 0x0000f000) >> 8) |
171 ((pix & 0x000000f0) >> 4);
172}
173
174#endif
175

source code of linux/drivers/gpu/drm/drm_format_internal.h