1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _FB_DRAW_H
3#define _FB_DRAW_H
4
5#include <asm/types.h>
6#include <linux/fb.h>
7#include <linux/bug.h>
8
9 /*
10 * Compose two values, using a bitmask as decision value
11 * This is equivalent to (a & mask) | (b & ~mask)
12 */
13
14static inline unsigned long
15comp(unsigned long a, unsigned long b, unsigned long mask)
16{
17 return ((a ^ b) & mask) ^ b;
18}
19
20 /*
21 * Create a pattern with the given pixel's color
22 */
23
24#if BITS_PER_LONG == 64
25static inline unsigned long
26pixel_to_pat( u32 bpp, u32 pixel)
27{
28 switch (bpp) {
29 case 1:
30 return 0xfffffffffffffffful*pixel;
31 case 2:
32 return 0x5555555555555555ul*pixel;
33 case 4:
34 return 0x1111111111111111ul*pixel;
35 case 8:
36 return 0x0101010101010101ul*pixel;
37 case 12:
38 return 0x1001001001001001ul*pixel;
39 case 16:
40 return 0x0001000100010001ul*pixel;
41 case 24:
42 return 0x0001000001000001ul*pixel;
43 case 32:
44 return 0x0000000100000001ul*pixel;
45 default:
46 WARN(1, "pixel_to_pat(): unsupported pixelformat %d\n", bpp);
47 return 0;
48 }
49}
50#else
51static inline unsigned long
52pixel_to_pat( u32 bpp, u32 pixel)
53{
54 switch (bpp) {
55 case 1:
56 return 0xfffffffful*pixel;
57 case 2:
58 return 0x55555555ul*pixel;
59 case 4:
60 return 0x11111111ul*pixel;
61 case 8:
62 return 0x01010101ul*pixel;
63 case 12:
64 return 0x01001001ul*pixel;
65 case 16:
66 return 0x00010001ul*pixel;
67 case 24:
68 return 0x01000001ul*pixel;
69 case 32:
70 return 0x00000001ul*pixel;
71 default:
72 WARN(1, "pixel_to_pat(): unsupported pixelformat %d\n", bpp);
73 return 0;
74 }
75}
76#endif
77
78#ifdef CONFIG_FB_CFB_REV_PIXELS_IN_BYTE
79#if BITS_PER_LONG == 64
80#define REV_PIXELS_MASK1 0x5555555555555555ul
81#define REV_PIXELS_MASK2 0x3333333333333333ul
82#define REV_PIXELS_MASK4 0x0f0f0f0f0f0f0f0ful
83#else
84#define REV_PIXELS_MASK1 0x55555555ul
85#define REV_PIXELS_MASK2 0x33333333ul
86#define REV_PIXELS_MASK4 0x0f0f0f0ful
87#endif
88
89static inline unsigned long fb_rev_pixels_in_long(unsigned long val,
90 u32 bswapmask)
91{
92 if (bswapmask & 1)
93 val = comp(a: val >> 1, b: val << 1, REV_PIXELS_MASK1);
94 if (bswapmask & 2)
95 val = comp(a: val >> 2, b: val << 2, REV_PIXELS_MASK2);
96 if (bswapmask & 3)
97 val = comp(a: val >> 4, b: val << 4, REV_PIXELS_MASK4);
98 return val;
99}
100
101static inline u32 fb_shifted_pixels_mask_u32(struct fb_info *p, u32 index,
102 u32 bswapmask)
103{
104 u32 mask;
105
106 if (!bswapmask) {
107 mask = FB_SHIFT_HIGH(p, ~(u32)0, index);
108 } else {
109 mask = 0xff << FB_LEFT_POS(p, 8);
110 mask = FB_SHIFT_LOW(p, mask, index & (bswapmask)) & mask;
111 mask = FB_SHIFT_HIGH(p, mask, index & ~(bswapmask));
112#if defined(__i386__) || defined(__x86_64__)
113 /* Shift argument is limited to 0 - 31 on x86 based CPU's */
114 if(index + bswapmask < 32)
115#endif
116 mask |= FB_SHIFT_HIGH(p, ~(u32)0,
117 (index + bswapmask) & ~(bswapmask));
118 }
119 return mask;
120}
121
122static inline unsigned long fb_shifted_pixels_mask_long(struct fb_info *p,
123 u32 index,
124 u32 bswapmask)
125{
126 unsigned long mask;
127
128 if (!bswapmask) {
129 mask = FB_SHIFT_HIGH(p, ~0UL, index);
130 } else {
131 mask = 0xff << FB_LEFT_POS(p, 8);
132 mask = FB_SHIFT_LOW(p, mask, index & (bswapmask)) & mask;
133 mask = FB_SHIFT_HIGH(p, mask, index & ~(bswapmask));
134#if defined(__i386__) || defined(__x86_64__)
135 /* Shift argument is limited to 0 - 31 on x86 based CPU's */
136 if(index + bswapmask < BITS_PER_LONG)
137#endif
138 mask |= FB_SHIFT_HIGH(p, ~0UL,
139 (index + bswapmask) & ~(bswapmask));
140 }
141 return mask;
142}
143
144
145static inline u32 fb_compute_bswapmask(struct fb_info *info)
146{
147 u32 bswapmask = 0;
148 unsigned bpp = info->var.bits_per_pixel;
149
150 if ((bpp < 8) && (info->var.nonstd & FB_NONSTD_REV_PIX_IN_B)) {
151 /*
152 * Reversed order of pixel layout in bytes
153 * works only for 1, 2 and 4 bpp
154 */
155 bswapmask = 7 - bpp + 1;
156 }
157 return bswapmask;
158}
159
160#else /* CONFIG_FB_CFB_REV_PIXELS_IN_BYTE */
161
162static inline unsigned long fb_rev_pixels_in_long(unsigned long val,
163 u32 bswapmask)
164{
165 return val;
166}
167
168#define fb_shifted_pixels_mask_u32(p, i, b) FB_SHIFT_HIGH((p), ~(u32)0, (i))
169#define fb_shifted_pixels_mask_long(p, i, b) FB_SHIFT_HIGH((p), ~0UL, (i))
170#define fb_compute_bswapmask(...) 0
171
172#endif /* CONFIG_FB_CFB_REV_PIXELS_IN_BYTE */
173
174#define cpu_to_le_long _cpu_to_le_long(BITS_PER_LONG)
175#define _cpu_to_le_long(x) __cpu_to_le_long(x)
176#define __cpu_to_le_long(x) cpu_to_le##x
177
178#define le_long_to_cpu _le_long_to_cpu(BITS_PER_LONG)
179#define _le_long_to_cpu(x) __le_long_to_cpu(x)
180#define __le_long_to_cpu(x) le##x##_to_cpu
181
182static inline unsigned long rolx(unsigned long word, unsigned int shift, unsigned int x)
183{
184 return (word << shift) | (word >> (x - shift));
185}
186
187#endif /* FB_DRAW_H */
188

source code of linux/drivers/video/fbdev/core/fb_draw.h