1 /*
2 * Fast C2P (Chunky-to-Planar) Conversion
3 *
4 * Copyright (C) 2003-2008 Geert Uytterhoeven
5 *
6 * This file is subject to the terms and conditions of the GNU General Public
7 * License. See the file COPYING in the main directory of this archive
8 * for more details.
9 */
10
11 #include <linux/module.h>
12 #include <linux/string.h>
13
14 #include <asm/unaligned.h>
15
16 #include "c2p.h"
17 #include "c2p_core.h"
18
19
20 /*
21 * Perform a full C2P step on 16 8-bit pixels, stored in 4 32-bit words
22 * containing
23 * - 16 8-bit chunky pixels on input
24 * - permutated planar data (2 planes per 32-bit word) on output
25 */
26
27 static void c2p_16x8(u32 d[4])
28 {
29 transp4(d, 8, 2);
30 transp4(d, 1, 2);
31 transp4x(d, 16, 2);
32 transp4x(d, 2, 2);
33 transp4(d, 4, 1);
34 }
35
36
37 /*
38 * Array containing the permutation indices of the planar data after c2p
39 */
40
41 static const int perm_c2p_16x8[4] = { 1, 3, 0, 2 };
42
43
44 /*
45 * Store a full block of iplan2 data after c2p conversion
46 */
47
48 static inline void store_iplan2(void *dst, u32 bpp, u32 d[4])
49 {
50 int i;
51
52 for (i = 0; i < bpp/2; i++, dst += 4)
53 put_unaligned_be32(d[perm_c2p_16x8[i]], dst);
54 }
55
56
57 /*
58 * Store a partial block of iplan2 data after c2p conversion
59 */
60
61 static inline void store_iplan2_masked(void *dst, u32 bpp, u32 d[4], u32 mask)
62 {
63 int i;
64
65 for (i = 0; i < bpp/2; i++, dst += 4)
66 put_unaligned_be32(comp(d[perm_c2p_16x8[i]],
67 get_unaligned_be32(dst), mask),
68 dst);
69 }
70
71
72 /*
73 * c2p_iplan2 - Copy 8-bit chunky image data to an interleaved planar
74 * frame buffer with 2 bytes of interleave
75 * @dst: Starting address of the planar frame buffer
76 * @dx: Horizontal destination offset (in pixels)
77 * @dy: Vertical destination offset (in pixels)
78 * @width: Image width (in pixels)
79 * @height: Image height (in pixels)
80 * @dst_nextline: Frame buffer offset to the next line (in bytes)
81 * @src_nextline: Image offset to the next line (in bytes)
82 * @bpp: Bits per pixel of the planar frame buffer (2, 4, or 8)
83 */
84
85 void c2p_iplan2(void *dst, const void *src, u32 dx, u32 dy, u32 width,
86 u32 height, u32 dst_nextline, u32 src_nextline, u32 bpp)
87 {
88 union {
89 u8 pixels[16];
90 u32 words[4];
91 } d;
92 u32 dst_idx, first, last, w;
93 const u8 *c;
94 void *p;
95
96 dst += dy*dst_nextline+(dx & ~15)*bpp;
97 dst_idx = dx % 16;
98 first = 0xffffU >> dst_idx;
99 first |= first << 16;
100 last = 0xffffU ^ (0xffffU >> ((dst_idx+width) % 16));
101 last |= last << 16;
102 while (height--) {
103 c = src;
104 p = dst;
105 w = width;
106 if (dst_idx+width <= 16) {
107 /* Single destination word */
108 first &= last;
109 memset(d.pixels, 0, sizeof(d));
110 memcpy(d.pixels+dst_idx, c, width);
111 c += width;
112 c2p_16x8(d.words);
113 store_iplan2_masked(p, bpp, d.words, first);
114 p += bpp*2;
115 } else {
116 /* Multiple destination words */
117 w = width;
118 /* Leading bits */
119 if (dst_idx) {
120 w = 16 - dst_idx;
121 memset(d.pixels, 0, dst_idx);
122 memcpy(d.pixels+dst_idx, c, w);
123 c += w;
124 c2p_16x8(d.words);
125 store_iplan2_masked(p, bpp, d.words, first);
126 p += bpp*2;
127 w = width-w;
128 }
129 /* Main chunk */
130 while (w >= 16) {
131 memcpy(d.pixels, c, 16);
132 c += 16;
133 c2p_16x8(d.words);
134 store_iplan2(p, bpp, d.words);
135 p += bpp*2;
136 w -= 16;
137 }
138 /* Trailing bits */
139 w %= 16;
140 if (w > 0) {
141 memcpy(d.pixels, c, w);
142 memset(d.pixels+w, 0, 16-w);
143 c2p_16x8(d.words);
144 store_iplan2_masked(p, bpp, d.words, last);
145 }
146 }
147 src += src_nextline;
148 dst += dst_nextline;
149 }
150 }
151 EXPORT_SYMBOL_GPL(c2p_iplan2);
152
153 MODULE_LICENSE("GPL");