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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/video/c2p.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'drivers/video/c2p.c')
-rw-r--r--drivers/video/c2p.c229
1 files changed, 229 insertions, 0 deletions
diff --git a/drivers/video/c2p.c b/drivers/video/c2p.c
new file mode 100644
index 000000000000..5c30bbd33054
--- /dev/null
+++ b/drivers/video/c2p.c
@@ -0,0 +1,229 @@
1/*
2 * Fast C2P (Chunky-to-Planar) Conversion
3 *
4 * Copyright (C) 2003 Geert Uytterhoeven
5 *
6 * NOTES:
7 * - This code was inspired by Scout's C2P tutorial
8 * - It assumes to run on a big endian system
9 *
10 * This file is subject to the terms and conditions of the GNU General Public
11 * License. See the file COPYING in the main directory of this archive
12 * for more details.
13 */
14
15#include <linux/string.h>
16#include "c2p.h"
17
18
19 /*
20 * Basic transpose step
21 */
22
23#define _transp(d, i1, i2, shift, mask) \
24 do { \
25 u32 t = (d[i1] ^ (d[i2] >> shift)) & mask; \
26 d[i1] ^= t; \
27 d[i2] ^= t << shift; \
28 } while (0)
29
30static inline u32 get_mask(int n)
31{
32 switch (n) {
33 case 1:
34 return 0x55555555;
35 break;
36
37 case 2:
38 return 0x33333333;
39 break;
40
41 case 4:
42 return 0x0f0f0f0f;
43 break;
44
45 case 8:
46 return 0x00ff00ff;
47 break;
48
49 case 16:
50 return 0x0000ffff;
51 break;
52 }
53 return 0;
54}
55
56#define transp_nx1(d, n) \
57 do { \
58 u32 mask = get_mask(n); \
59 /* First block */ \
60 _transp(d, 0, 1, n, mask); \
61 /* Second block */ \
62 _transp(d, 2, 3, n, mask); \
63 /* Third block */ \
64 _transp(d, 4, 5, n, mask); \
65 /* Fourth block */ \
66 _transp(d, 6, 7, n, mask); \
67 } while (0)
68
69#define transp_nx2(d, n) \
70 do { \
71 u32 mask = get_mask(n); \
72 /* First block */ \
73 _transp(d, 0, 2, n, mask); \
74 _transp(d, 1, 3, n, mask); \
75 /* Second block */ \
76 _transp(d, 4, 6, n, mask); \
77 _transp(d, 5, 7, n, mask); \
78 } while (0)
79
80#define transp_nx4(d, n) \
81 do { \
82 u32 mask = get_mask(n); \
83 _transp(d, 0, 4, n, mask); \
84 _transp(d, 1, 5, n, mask); \
85 _transp(d, 2, 6, n, mask); \
86 _transp(d, 3, 7, n, mask); \
87 } while (0)
88
89#define transp(d, n, m) transp_nx ## m(d, n)
90
91
92 /*
93 * Perform a full C2P step on 32 8-bit pixels, stored in 8 32-bit words
94 * containing
95 * - 32 8-bit chunky pixels on input
96 * - permuted planar data on output
97 */
98
99static void c2p_8bpp(u32 d[8])
100{
101 transp(d, 16, 4);
102 transp(d, 8, 2);
103 transp(d, 4, 1);
104 transp(d, 2, 4);
105 transp(d, 1, 2);
106}
107
108
109 /*
110 * Array containing the permution indices of the planar data after c2p
111 */
112
113static const int perm_c2p_8bpp[8] = { 7, 5, 3, 1, 6, 4, 2, 0 };
114
115
116 /*
117 * Compose two values, using a bitmask as decision value
118 * This is equivalent to (a & mask) | (b & ~mask)
119 */
120
121static inline unsigned long comp(unsigned long a, unsigned long b,
122 unsigned long mask)
123{
124 return ((a ^ b) & mask) ^ b;
125}
126
127
128 /*
129 * Store a full block of planar data after c2p conversion
130 */
131
132static inline void store_planar(char *dst, u32 dst_inc, u32 bpp, u32 d[8])
133{
134 int i;
135
136 for (i = 0; i < bpp; i++, dst += dst_inc)
137 *(u32 *)dst = d[perm_c2p_8bpp[i]];
138}
139
140
141 /*
142 * Store a partial block of planar data after c2p conversion
143 */
144
145static inline void store_planar_masked(char *dst, u32 dst_inc, u32 bpp,
146 u32 d[8], u32 mask)
147{
148 int i;
149
150 for (i = 0; i < bpp; i++, dst += dst_inc)
151 *(u32 *)dst = comp(d[perm_c2p_8bpp[i]], *(u32 *)dst, mask);
152}
153
154
155 /*
156 * c2p - Copy 8-bit chunky image data to a planar frame buffer
157 * @dst: Starting address of the planar frame buffer
158 * @dx: Horizontal destination offset (in pixels)
159 * @dy: Vertical destination offset (in pixels)
160 * @width: Image width (in pixels)
161 * @height: Image height (in pixels)
162 * @dst_nextline: Frame buffer offset to the next line (in bytes)
163 * @dst_nextplane: Frame buffer offset to the next plane (in bytes)
164 * @src_nextline: Image offset to the next line (in bytes)
165 * @bpp: Bits per pixel of the planar frame buffer (1-8)
166 */
167
168void c2p(u8 *dst, const u8 *src, u32 dx, u32 dy, u32 width, u32 height,
169 u32 dst_nextline, u32 dst_nextplane, u32 src_nextline, u32 bpp)
170{
171 int dst_idx;
172 u32 d[8], first, last, w;
173 const u8 *c;
174 u8 *p;
175
176 dst += dy*dst_nextline+(dx & ~31);
177 dst_idx = dx % 32;
178 first = ~0UL >> dst_idx;
179 last = ~(~0UL >> ((dst_idx+width) % 32));
180 while (height--) {
181 c = src;
182 p = dst;
183 w = width;
184 if (dst_idx+width <= 32) {
185 /* Single destination word */
186 first &= last;
187 memset(d, 0, sizeof(d));
188 memcpy((u8 *)d+dst_idx, c, width);
189 c += width;
190 c2p_8bpp(d);
191 store_planar_masked(p, dst_nextplane, bpp, d, first);
192 p += 4;
193 } else {
194 /* Multiple destination words */
195 w = width;
196 /* Leading bits */
197 if (dst_idx) {
198 w = 32 - dst_idx;
199 memset(d, 0, dst_idx);
200 memcpy((u8 *)d+dst_idx, c, w);
201 c += w;
202 c2p_8bpp(d);
203 store_planar_masked(p, dst_nextplane, bpp, d, first);
204 p += 4;
205 w = width-w;
206 }
207 /* Main chunk */
208 while (w >= 32) {
209 memcpy(d, c, 32);
210 c += 32;
211 c2p_8bpp(d);
212 store_planar(p, dst_nextplane, bpp, d);
213 p += 4;
214 w -= 32;
215 }
216 /* Trailing bits */
217 w %= 32;
218 if (w > 0) {
219 memcpy(d, c, w);
220 memset((u8 *)d+w, 0, 32-w);
221 c2p_8bpp(d);
222 store_planar_masked(p, dst_nextplane, bpp, d, last);
223 }
224 }
225 src += src_nextline;
226 dst += dst_nextline;
227 }
228}
229