aboutsummaryrefslogtreecommitdiff
path: root/drivers/video/fbdev/c2p_planar.c
blob: ec7ac8526f060b8c4cc6cad632b5dd673b2fd3e8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
/*
 *  Fast C2P (Chunky-to-Planar) Conversion
 *
 *  Copyright (C) 2003-2008 Geert Uytterhoeven
 *
 *  This file is subject to the terms and conditions of the GNU General Public
 *  License. See the file COPYING in the main directory of this archive
 *  for more details.
 */

#include <linux/module.h>
#include <linux/string.h>

#include <asm/unaligned.h>

#include "c2p.h"
#include "c2p_core.h"


    /*
     *  Perform a full C2P step on 32 8-bit pixels, stored in 8 32-bit words
     *  containing
     *    - 32 8-bit chunky pixels on input
     *    - permutated planar data (1 plane per 32-bit word) on output
     */

static void c2p_32x8(u32 d[8])
{
	transp8(d, 16, 4);
	transp8(d, 8, 2);
	transp8(d, 4, 1);
	transp8(d, 2, 4);
	transp8(d, 1, 2);
}


    /*
     *  Array containing the permutation indices of the planar data after c2p
     */

static const int perm_c2p_32x8[8] = { 7, 5, 3, 1, 6, 4, 2, 0 };


    /*
     *  Store a full block of planar data after c2p conversion
     */

static inline void store_planar(void *dst, u32 dst_inc, u32 bpp, u32 d[8])
{
	int i;

	for (i = 0; i < bpp; i++, dst += dst_inc)
		put_unaligned_be32(d[perm_c2p_32x8[i]], dst);
}


    /*
     *  Store a partial block of planar data after c2p conversion
     */

static inline void store_planar_masked(void *dst, u32 dst_inc, u32 bpp,
				       u32 d[8], u32 mask)
{
	int i;

	for (i = 0; i < bpp; i++, dst += dst_inc)
		put_unaligned_be32(comp(d[perm_c2p_32x8[i]],
					get_unaligned_be32(dst), mask),
				   dst);
}


    /*
     *  c2p_planar - Copy 8-bit chunky image data to a planar frame buffer
     *  @dst: Starting address of the planar frame buffer
     *  @dx: Horizontal destination offset (in pixels)
     *  @dy: Vertical destination offset (in pixels)
     *  @width: Image width (in pixels)
     *  @height: Image height (in pixels)
     *  @dst_nextline: Frame buffer offset to the next line (in bytes)
     *  @dst_nextplane: Frame buffer offset to the next plane (in bytes)
     *  @src_nextline: Image offset to the next line (in bytes)
     *  @bpp: Bits per pixel of the planar frame buffer (1-8)
     */

void c2p_planar(void *dst, const void *src, u32 dx, u32 dy, u32 width,
		u32 height, u32 dst_nextline, u32 dst_nextplane,
		u32 src_nextline, u32 bpp)
{
	union {
		u8 pixels[32];
		u32 words[8];
	} d;
	u32 dst_idx, first, last, w;
	const u8 *c;
	void *p;

	dst += dy*dst_nextline+(dx & ~31);
	dst_idx = dx % 32;
	first = 0xffffffffU >> dst_idx;
	last = ~(0xffffffffU >> ((dst_idx+width) % 32));
	while (height--) {
		c = src;
		p = dst;
		w = width;
		if (dst_idx+width <= 32) {
			/* Single destination word */
			first &= last;
			memset(d.pixels, 0, sizeof(d));
			memcpy(d.pixels+dst_idx, c, width);
			c += width;
			c2p_32x8(d.words);
			store_planar_masked(p, dst_nextplane, bpp, d.words,
					    first);
			p += 4;
		} else {
			/* Multiple destination words */
			w = width;
			/* Leading bits */
			if (dst_idx) {
				w = 32 - dst_idx;
				memset(d.pixels, 0, dst_idx);
				memcpy(d.pixels+dst_idx, c, w);
				c += w;
				c2p_32x8(d.words);
				store_planar_masked(p, dst_nextplane, bpp,
						    d.words, first);
				p += 4;
				w = width-w;
			}
			/* Main chunk */
			while (w >= 32) {
				memcpy(d.pixels, c, 32);
				c += 32;
				c2p_32x8(d.words);
				store_planar(p, dst_nextplane, bpp, d.words);
				p += 4;
				w -= 32;
			}
			/* Trailing bits */
			w %= 32;
			if (w > 0) {
				memcpy(d.pixels, c, w);
				memset(d.pixels+w, 0, 32-w);
				c2p_32x8(d.words);
				store_planar_masked(p, dst_nextplane, bpp,
						    d.words, last);
			}
		}
		src += src_nextline;
		dst += dst_nextline;
	}
}
EXPORT_SYMBOL_GPL(c2p_planar);

MODULE_LICENSE("GPL");