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authorGeert Uytterhoeven <geert@linux-m68k.org>2009-01-04 11:58:20 +0100
committerGeert Uytterhoeven <geert@linux-m68k.org>2009-01-12 20:56:31 +0100
commit2cd1de0a0ff1d3da08ff1f1437cf4a44deae6a00 (patch)
treed384dea3a349ee2f2f897e242882cbbb7e56a705 /drivers/video/c2p_core.h
parent1f034456c140a8677d0ff3a9bdb3c4b620aae2cb (diff)
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fbdev: c2p - Extract common c2p core to c2p_core.h
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Diffstat (limited to 'drivers/video/c2p_core.h')
-rw-r--r--drivers/video/c2p_core.h106
1 files changed, 106 insertions, 0 deletions
diff --git a/drivers/video/c2p_core.h b/drivers/video/c2p_core.h
new file mode 100644
index 000000000000..3573cf723e43
--- /dev/null
+++ b/drivers/video/c2p_core.h
@@ -0,0 +1,106 @@
+/*
+ * Fast C2P (Chunky-to-Planar) Conversion
+ *
+ * Copyright (C) 2003-2008 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.
+ */
+
+
+ /*
+ * Basic transpose step
+ */
+
+static inline void _transp(u32 d[], unsigned int i1, unsigned int i2,
+ unsigned int shift, u32 mask)
+{
+ u32 t = (d[i1] ^ (d[i2] >> shift)) & mask;
+
+ d[i1] ^= t;
+ d[i2] ^= t << shift;
+}
+
+
+extern void c2p_unsupported(void);
+
+static inline u32 get_mask(unsigned int n)
+{
+ switch (n) {
+ case 1:
+ return 0x55555555;
+
+ case 2:
+ return 0x33333333;
+
+ case 4:
+ return 0x0f0f0f0f;
+
+ case 8:
+ return 0x00ff00ff;
+
+ case 16:
+ return 0x0000ffff;
+ }
+
+ c2p_unsupported();
+ return 0;
+}
+
+
+ /*
+ * Transpose operations on 8 32-bit words
+ */
+
+static inline void transp8(u32 d[], unsigned int n, unsigned int m)
+{
+ u32 mask = get_mask(n);
+
+ switch (m) {
+ case 1:
+ /* First n x 1 block */
+ _transp(d, 0, 1, n, mask);
+ /* Second n x 1 block */
+ _transp(d, 2, 3, n, mask);
+ /* Third n x 1 block */
+ _transp(d, 4, 5, n, mask);
+ /* Fourth n x 1 block */
+ _transp(d, 6, 7, n, mask);
+ return;
+
+ case 2:
+ /* First n x 2 block */
+ _transp(d, 0, 2, n, mask);
+ _transp(d, 1, 3, n, mask);
+ /* Second n x 2 block */
+ _transp(d, 4, 6, n, mask);
+ _transp(d, 5, 7, n, mask);
+ return;
+
+ case 4:
+ /* Single n x 4 block */
+ _transp(d, 0, 4, n, mask);
+ _transp(d, 1, 5, n, mask);
+ _transp(d, 2, 6, n, mask);
+ _transp(d, 3, 7, n, mask);
+ return;
+ }
+
+ c2p_unsupported();
+}
+
+
+ /*
+ * Compose two values, using a bitmask as decision value
+ * This is equivalent to (a & mask) | (b & ~mask)
+ */
+
+static inline u32 comp(u32 a, u32 b, u32 mask)
+{
+ return ((a ^ b) & mask) ^ b;
+}