/*
   *  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 16 8-bit pixels, stored in 4 32-bit words
       *  containing
       *    - 16 8-bit chunky pixels on input
       *    - permutated planar data (2 planes per 32-bit word) on output
       */
  
  static void c2p_16x8(u32 d[4])
  {
  	transp4(d, 8, 2);
  	transp4(d, 1, 2);
  	transp4x(d, 16, 2);
  	transp4x(d, 2, 2);
  	transp4(d, 4, 1);
  }
  
  
      /*
       *  Array containing the permutation indices of the planar data after c2p
       */
  
  static const int perm_c2p_16x8[4] = { 1, 3, 0, 2 };
  
  
      /*
       *  Store a full block of iplan2 data after c2p conversion
       */
  
  static inline void store_iplan2(void *dst, u32 bpp, u32 d[4])
  {
  	int i;
  
  	for (i = 0; i < bpp/2; i++, dst += 4)
  		put_unaligned_be32(d[perm_c2p_16x8[i]], dst);
  }
  
  
      /*
       *  Store a partial block of iplan2 data after c2p conversion
       */
  
  static inline void store_iplan2_masked(void *dst, u32 bpp, u32 d[4], u32 mask)
  {
  	int i;
  
  	for (i = 0; i < bpp/2; i++, dst += 4)
  		put_unaligned_be32(comp(d[perm_c2p_16x8[i]],
  					get_unaligned_be32(dst), mask),
  				   dst);
  }
  
  
      /*
       *  c2p_iplan2 - Copy 8-bit chunky image data to an interleaved planar
       *  frame buffer with 2 bytes of interleave
       *  @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)
       *  @src_nextline: Image offset to the next line (in bytes)
       *  @bpp: Bits per pixel of the planar frame buffer (2, 4, or 8)
       */
  
  void c2p_iplan2(void *dst, const void *src, u32 dx, u32 dy, u32 width,
  		u32 height, u32 dst_nextline, u32 src_nextline, u32 bpp)
  {
  	union {
  		u8 pixels[16];
  		u32 words[4];
  	} d;
  	u32 dst_idx, first, last, w;
  	const u8 *c;
  	void *p;
  
  	dst += dy*dst_nextline+(dx & ~15)*bpp;
  	dst_idx = dx % 16;
  	first = 0xffffU >> dst_idx;
  	first |= first << 16;
  	last = 0xffffU ^ (0xffffU >> ((dst_idx+width) % 16));
  	last |= last << 16;
  	while (height--) {
  		c = src;
  		p = dst;
  		w = width;
  		if (dst_idx+width <= 16) {
  			/* Single destination word */
  			first &= last;
  			memset(d.pixels, 0, sizeof(d));
  			memcpy(d.pixels+dst_idx, c, width);
  			c += width;
  			c2p_16x8(d.words);
  			store_iplan2_masked(p, bpp, d.words, first);
  			p += bpp*2;
  		} else {
  			/* Multiple destination words */
  			w = width;
  			/* Leading bits */
  			if (dst_idx) {
  				w = 16 - dst_idx;
  				memset(d.pixels, 0, dst_idx);
  				memcpy(d.pixels+dst_idx, c, w);
  				c += w;
  				c2p_16x8(d.words);
  				store_iplan2_masked(p, bpp, d.words, first);
  				p += bpp*2;
  				w = width-w;
  			}
  			/* Main chunk */
  			while (w >= 16) {
  				memcpy(d.pixels, c, 16);
  				c += 16;
  				c2p_16x8(d.words);
  				store_iplan2(p, bpp, d.words);
  				p += bpp*2;
  				w -= 16;
  			}
  			/* Trailing bits */
  			w %= 16;
  			if (w > 0) {
  				memcpy(d.pixels, c, w);
  				memset(d.pixels+w, 0, 16-w);
  				c2p_16x8(d.words);
  				store_iplan2_masked(p, bpp, d.words, last);
  			}
  		}
  		src += src_nextline;
  		dst += dst_nextline;
  	}
  }
  EXPORT_SYMBOL_GPL(c2p_iplan2);
  
  MODULE_LICENSE("GPL");