/*
   *  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");