xref: /linux/drivers/gpu/drm/drm_format_internal.h (revision fcab107abe1ab5be9dbe874baa722372da8f4f73)
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 
9 /*
10  * Each pixel-format conversion helper takes a raw pixel in a
11  * specific input format and returns a raw pixel in a specific
12  * output format. All pixels are in little-endian byte order.
13  *
14  * Function names are
15  *
16  *   drm_pixel_<input>_to_<output>_<algorithm>()
17  *
18  * where <input> and <output> refer to pixel formats. The
19  * <algorithm> is optional and hints to the method used for the
20  * conversion. Helpers with no algorithm given apply pixel-bit
21  * shifting.
22  *
23  * The argument type is u32. We expect this to be wide enough to
24  * hold all conversion input from 32-bit RGB to any output format.
25  * The Linux kernel should avoid format conversion for anything
26  * but XRGB8888 input data. Converting from other format can still
27  * be acceptable in some cases.
28  *
29  * The return type is u32. It is wide enough to hold all conversion
30  * output from XRGB8888. For output formats wider than 32 bit, a
31  * return type of u64 would be acceptable.
32  */
33 
34 /*
35  * Conversions from XRGB8888
36  */
37 
38 static inline u32 drm_pixel_xrgb8888_to_r8_bt601(u32 pix)
39 {
40 	u32 r = (pix & 0x00ff0000) >> 16;
41 	u32 g = (pix & 0x0000ff00) >> 8;
42 	u32 b =  pix & 0x000000ff;
43 
44 	/* ITU-R BT.601: Y = 0.299 R + 0.587 G + 0.114 B */
45 	return (3 * r + 6 * g + b) / 10;
46 }
47 
48 static inline u32 drm_pixel_xrgb8888_to_rgb332(u32 pix)
49 {
50 	return ((pix & 0x00e00000) >> 16) |
51 	       ((pix & 0x0000e000) >> 11) |
52 	       ((pix & 0x000000c0) >> 6);
53 }
54 
55 static inline u32 drm_pixel_xrgb8888_to_rgb565(u32 pix)
56 {
57 	return ((pix & 0x00f80000) >> 8) |
58 	       ((pix & 0x0000fc00) >> 5) |
59 	       ((pix & 0x000000f8) >> 3);
60 }
61 
62 static inline u32 drm_pixel_xrgb8888_to_rgbx5551(u32 pix)
63 {
64 	return ((pix & 0x00f80000) >> 8) |
65 	       ((pix & 0x0000f800) >> 5) |
66 	       ((pix & 0x000000f8) >> 2);
67 }
68 
69 static inline u32 drm_pixel_xrgb8888_to_rgba5551(u32 pix)
70 {
71 	return drm_pixel_xrgb8888_to_rgbx5551(pix) |
72 	       BIT(0); /* set alpha bit */
73 }
74 
75 static inline u32 drm_pixel_xrgb8888_to_xrgb1555(u32 pix)
76 {
77 	return ((pix & 0x00f80000) >> 9) |
78 	       ((pix & 0x0000f800) >> 6) |
79 	       ((pix & 0x000000f8) >> 3);
80 }
81 
82 static inline u32 drm_pixel_xrgb8888_to_argb1555(u32 pix)
83 {
84 	return BIT(15) | /* set alpha bit */
85 	       drm_pixel_xrgb8888_to_xrgb1555(pix);
86 }
87 
88 static inline u32 drm_pixel_xrgb8888_to_rgb888(u32 pix)
89 {
90 	return pix & GENMASK(23, 0);
91 }
92 
93 static inline u32 drm_pixel_xrgb8888_to_bgr888(u32 pix)
94 {
95 	return ((pix & 0x00ff0000) >> 16) |
96 	       ((pix & 0x0000ff00)) |
97 	       ((pix & 0x000000ff) << 16);
98 }
99 
100 static inline u32 drm_pixel_xrgb8888_to_argb8888(u32 pix)
101 {
102 	return GENMASK(31, 24) | /* fill alpha bits */
103 	       pix;
104 }
105 
106 static inline u32 drm_pixel_xrgb8888_to_xbgr8888(u32 pix)
107 {
108 	return ((pix & 0xff000000)) | /* also copy filler bits */
109 	       ((pix & 0x00ff0000) >> 16) |
110 	       ((pix & 0x0000ff00)) |
111 	       ((pix & 0x000000ff) << 16);
112 }
113 
114 static inline u32 drm_pixel_xrgb8888_to_abgr8888(u32 pix)
115 {
116 	return GENMASK(31, 24) | /* fill alpha bits */
117 	       drm_pixel_xrgb8888_to_xbgr8888(pix);
118 }
119 
120 static inline u32 drm_pixel_xrgb8888_to_xrgb2101010(u32 pix)
121 {
122 	pix = ((pix & 0x000000ff) << 2) |
123 	      ((pix & 0x0000ff00) << 4) |
124 	      ((pix & 0x00ff0000) << 6);
125 	return pix | ((pix >> 8) & 0x00300c03);
126 }
127 
128 static inline u32 drm_pixel_xrgb8888_to_argb2101010(u32 pix)
129 {
130 	return GENMASK(31, 30) | /* set alpha bits */
131 	       drm_pixel_xrgb8888_to_xrgb2101010(pix);
132 }
133 
134 static inline u32 drm_pixel_xrgb8888_to_xbgr2101010(u32 pix)
135 {
136 	pix = ((pix & 0x00ff0000) >> 14) |
137 	      ((pix & 0x0000ff00) << 4) |
138 	      ((pix & 0x000000ff) << 22);
139 	return pix | ((pix >> 8) & 0x00300c03);
140 }
141 
142 static inline u32 drm_pixel_xrgb8888_to_abgr2101010(u32 pix)
143 {
144 	return GENMASK(31, 30) | /* set alpha bits */
145 	       drm_pixel_xrgb8888_to_xbgr2101010(pix);
146 }
147 
148 /*
149  * Conversion from ARGB8888
150  */
151 
152 static inline u32 drm_pixel_argb8888_to_argb4444(u32 pix)
153 {
154 	return ((pix & 0xf0000000) >> 16) |
155 	       ((pix & 0x00f00000) >> 12) |
156 	       ((pix & 0x0000f000) >> 8) |
157 	       ((pix & 0x000000f0) >> 4);
158 }
159 
160 #endif
161