aboutsummaryrefslogtreecommitdiff
path: root/drivers/video/c2p.c
diff options
context:
space:
mode:
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 00000000000..5c30bbd3305
--- /dev/null
+++ b/drivers/video/c2p.c
@@ -0,0 +1,229 @@
+/*
+ * Fast C2P (Chunky-to-Planar) Conversion
+ *
+ * Copyright (C) 2003 Geert Uytterhoeven
+ *
+ * NOTES:
+ * - This code was inspired by Scout's C2P tutorial
+ * - It assumes to run on a big endian system
+ *
+ * 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/string.h>
+#include "c2p.h"
+
+
+ /*
+ * Basic transpose step
+ */
+
+#define _transp(d, i1, i2, shift, mask) \
+ do { \
+ u32 t = (d[i1] ^ (d[i2] >> shift)) & mask; \
+ d[i1] ^= t; \
+ d[i2] ^= t << shift; \
+ } while (0)
+
+static inline u32 get_mask(int n)
+{
+ switch (n) {
+ case 1:
+ return 0x55555555;
+ break;
+
+ case 2:
+ return 0x33333333;
+ break;
+
+ case 4:
+ return 0x0f0f0f0f;
+ break;
+
+ case 8:
+ return 0x00ff00ff;
+ break;
+
+ case 16:
+ return 0x0000ffff;
+ break;
+ }
+ return 0;
+}
+
+#define transp_nx1(d, n) \
+ do { \
+ u32 mask = get_mask(n); \
+ /* First block */ \
+ _transp(d, 0, 1, n, mask); \
+ /* Second block */ \
+ _transp(d, 2, 3, n, mask); \
+ /* Third block */ \
+ _transp(d, 4, 5, n, mask); \
+ /* Fourth block */ \
+ _transp(d, 6, 7, n, mask); \
+ } while (0)
+
+#define transp_nx2(d, n) \
+ do { \
+ u32 mask = get_mask(n); \
+ /* First block */ \
+ _transp(d, 0, 2, n, mask); \
+ _transp(d, 1, 3, n, mask); \
+ /* Second block */ \
+ _transp(d, 4, 6, n, mask); \
+ _transp(d, 5, 7, n, mask); \
+ } while (0)
+
+#define transp_nx4(d, n) \
+ do { \
+ u32 mask = get_mask(n); \
+ _transp(d, 0, 4, n, mask); \
+ _transp(d, 1, 5, n, mask); \
+ _transp(d, 2, 6, n, mask); \
+ _transp(d, 3, 7, n, mask); \
+ } while (0)
+
+#define transp(d, n, m) transp_nx ## m(d, n)
+
+
+ /*
+ * Perform a full C2P step on 32 8-bit pixels, stored in 8 32-bit words
+ * containing
+ * - 32 8-bit chunky pixels on input
+ * - permuted planar data on output
+ */
+
+static void c2p_8bpp(u32 d[8])
+{
+ transp(d, 16, 4);
+ transp(d, 8, 2);
+ transp(d, 4, 1);
+ transp(d, 2, 4);
+ transp(d, 1, 2);
+}
+
+
+ /*
+ * Array containing the permution indices of the planar data after c2p
+ */
+
+static const int perm_c2p_8bpp[8] = { 7, 5, 3, 1, 6, 4, 2, 0 };
+
+
+ /*
+ * Compose two values, using a bitmask as decision value
+ * This is equivalent to (a & mask) | (b & ~mask)
+ */
+
+static inline unsigned long comp(unsigned long a, unsigned long b,
+ unsigned long mask)
+{
+ return ((a ^ b) & mask) ^ b;
+}
+
+
+ /*
+ * Store a full block of planar data after c2p conversion
+ */
+
+static inline void store_planar(char *dst, u32 dst_inc, u32 bpp, u32 d[8])
+{
+ int i;
+
+ for (i = 0; i < bpp; i++, dst += dst_inc)
+ *(u32 *)dst = d[perm_c2p_8bpp[i]];
+}
+
+
+ /*
+ * Store a partial block of planar data after c2p conversion
+ */
+
+static inline void store_planar_masked(char *dst, u32 dst_inc, u32 bpp,
+ u32 d[8], u32 mask)
+{
+ int i;
+
+ for (i = 0; i < bpp; i++, dst += dst_inc)
+ *(u32 *)dst = comp(d[perm_c2p_8bpp[i]], *(u32 *)dst, mask);
+}
+
+
+ /*
+ * c2p - 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(u8 *dst, const u8 *src, u32 dx, u32 dy, u32 width, u32 height,
+ u32 dst_nextline, u32 dst_nextplane, u32 src_nextline, u32 bpp)
+{
+ int dst_idx;
+ u32 d[8], first, last, w;
+ const u8 *c;
+ u8 *p;
+
+ dst += dy*dst_nextline+(dx & ~31);
+ dst_idx = dx % 32;
+ first = ~0UL >> dst_idx;
+ last = ~(~0UL >> ((dst_idx+width) % 32));
+ while (height--) {
+ c = src;
+ p = dst;
+ w = width;
+ if (dst_idx+width <= 32) {
+ /* Single destination word */
+ first &= last;
+ memset(d, 0, sizeof(d));
+ memcpy((u8 *)d+dst_idx, c, width);
+ c += width;
+ c2p_8bpp(d);
+ store_planar_masked(p, dst_nextplane, bpp, d, first);
+ p += 4;
+ } else {
+ /* Multiple destination words */
+ w = width;
+ /* Leading bits */
+ if (dst_idx) {
+ w = 32 - dst_idx;
+ memset(d, 0, dst_idx);
+ memcpy((u8 *)d+dst_idx, c, w);
+ c += w;
+ c2p_8bpp(d);
+ store_planar_masked(p, dst_nextplane, bpp, d, first);
+ p += 4;
+ w = width-w;
+ }
+ /* Main chunk */
+ while (w >= 32) {
+ memcpy(d, c, 32);
+ c += 32;
+ c2p_8bpp(d);
+ store_planar(p, dst_nextplane, bpp, d);
+ p += 4;
+ w -= 32;
+ }
+ /* Trailing bits */
+ w %= 32;
+ if (w > 0) {
+ memcpy(d, c, w);
+ memset((u8 *)d+w, 0, 32-w);
+ c2p_8bpp(d);
+ store_planar_masked(p, dst_nextplane, bpp, d, last);
+ }
+ }
+ src += src_nextline;
+ dst += dst_nextline;
+ }
+}
+