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/export.h> 12 #include <linux/module.h> 13 #include <linux/string.h> 14 15 #include <linux/unaligned.h> 16 17 #include "c2p.h" 18 #include "c2p_core.h" 19 20 21 /* 22 * Perform a full C2P step on 16 8-bit pixels, stored in 4 32-bit words 23 * containing 24 * - 16 8-bit chunky pixels on input 25 * - permutated planar data (2 planes per 32-bit word) on output 26 */ 27 28 static void c2p_16x8(u32 d[4]) 29 { 30 transp4(d, 8, 2); 31 transp4(d, 1, 2); 32 transp4x(d, 16, 2); 33 transp4x(d, 2, 2); 34 transp4(d, 4, 1); 35 } 36 37 38 /* 39 * Array containing the permutation indices of the planar data after c2p 40 */ 41 42 static const int perm_c2p_16x8[4] = { 1, 3, 0, 2 }; 43 44 45 /* 46 * Store a full block of iplan2 data after c2p conversion 47 */ 48 49 static inline void store_iplan2(void *dst, u32 bpp, u32 d[4]) 50 { 51 int i; 52 53 for (i = 0; i < bpp/2; i++, dst += 4) 54 put_unaligned_be32(d[perm_c2p_16x8[i]], dst); 55 } 56 57 58 /* 59 * Store a partial block of iplan2 data after c2p conversion 60 */ 61 62 static inline void store_iplan2_masked(void *dst, u32 bpp, u32 d[4], u32 mask) 63 { 64 int i; 65 66 for (i = 0; i < bpp/2; i++, dst += 4) 67 put_unaligned_be32(comp(d[perm_c2p_16x8[i]], 68 get_unaligned_be32(dst), mask), 69 dst); 70 } 71 72 73 /* 74 * c2p_iplan2 - Copy 8-bit chunky image data to an interleaved planar 75 * frame buffer with 2 bytes of interleave 76 * @dst: Starting address of the planar frame buffer 77 * @dx: Horizontal destination offset (in pixels) 78 * @dy: Vertical destination offset (in pixels) 79 * @width: Image width (in pixels) 80 * @height: Image height (in pixels) 81 * @dst_nextline: Frame buffer offset to the next line (in bytes) 82 * @src_nextline: Image offset to the next line (in bytes) 83 * @bpp: Bits per pixel of the planar frame buffer (2, 4, or 8) 84 */ 85 86 void c2p_iplan2(void *dst, const void *src, u32 dx, u32 dy, u32 width, 87 u32 height, u32 dst_nextline, u32 src_nextline, u32 bpp) 88 { 89 union { 90 u8 pixels[16]; 91 u32 words[4]; 92 } d; 93 u32 dst_idx, first, last, w; 94 const u8 *c; 95 void *p; 96 97 dst += dy*dst_nextline+(dx & ~15)*bpp; 98 dst_idx = dx % 16; 99 first = 0xffffU >> dst_idx; 100 first |= first << 16; 101 last = 0xffffU ^ (0xffffU >> ((dst_idx+width) % 16)); 102 last |= last << 16; 103 while (height--) { 104 c = src; 105 p = dst; 106 w = width; 107 if (dst_idx+width <= 16) { 108 /* Single destination word */ 109 first &= last; 110 memset(d.pixels, 0, sizeof(d)); 111 memcpy(d.pixels+dst_idx, c, width); 112 c += width; 113 c2p_16x8(d.words); 114 store_iplan2_masked(p, bpp, d.words, first); 115 p += bpp*2; 116 } else { 117 /* Multiple destination words */ 118 w = width; 119 /* Leading bits */ 120 if (dst_idx) { 121 w = 16 - dst_idx; 122 memset(d.pixels, 0, dst_idx); 123 memcpy(d.pixels+dst_idx, c, w); 124 c += w; 125 c2p_16x8(d.words); 126 store_iplan2_masked(p, bpp, d.words, first); 127 p += bpp*2; 128 w = width-w; 129 } 130 /* Main chunk */ 131 while (w >= 16) { 132 memcpy(d.pixels, c, 16); 133 c += 16; 134 c2p_16x8(d.words); 135 store_iplan2(p, bpp, d.words); 136 p += bpp*2; 137 w -= 16; 138 } 139 /* Trailing bits */ 140 w %= 16; 141 if (w > 0) { 142 memcpy(d.pixels, c, w); 143 memset(d.pixels+w, 0, 16-w); 144 c2p_16x8(d.words); 145 store_iplan2_masked(p, bpp, d.words, last); 146 } 147 } 148 src += src_nextline; 149 dst += dst_nextline; 150 } 151 } 152 EXPORT_SYMBOL_GPL(c2p_iplan2); 153 154 MODULE_LICENSE("GPL"); 155