1 files changed, 229 insertions, 0 deletions

diff --git a/drivers/video/c2p.c b/drivers/video/c2p.c
new file mode 100644
index 000000000000..5c30bbd33054
--- /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;
+    }
+}
+