linux/drivers/video/cfbimgblt.c
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   1/*
   2 *  Generic BitBLT function for frame buffer with packed pixels of any depth.
   3 *
   4 *      Copyright (C)  June 1999 James Simmons
   5 *
   6 *  This file is subject to the terms and conditions of the GNU General Public
   7 *  License.  See the file COPYING in the main directory of this archive for
   8 *  more details.
   9 *
  10 * NOTES:
  11 *
  12 *    This function copys a image from system memory to video memory. The
  13 *  image can be a bitmap where each 0 represents the background color and
  14 *  each 1 represents the foreground color. Great for font handling. It can
  15 *  also be a color image. This is determined by image_depth. The color image
  16 *  must be laid out exactly in the same format as the framebuffer. Yes I know
  17 *  their are cards with hardware that coverts images of various depths to the
  18 *  framebuffer depth. But not every card has this. All images must be rounded
  19 *  up to the nearest byte. For example a bitmap 12 bits wide must be two 
  20 *  bytes width. 
  21 *
  22 *  Tony: 
  23 *  Incorporate mask tables similar to fbcon-cfb*.c in 2.4 API.  This speeds 
  24 *  up the code significantly.
  25 *  
  26 *  Code for depths not multiples of BITS_PER_LONG is still kludgy, which is
  27 *  still processed a bit at a time.   
  28 *
  29 *  Also need to add code to deal with cards endians that are different than
  30 *  the native cpu endians. I also need to deal with MSB position in the word.
  31 */
  32#include <linux/module.h>
  33#include <linux/string.h>
  34#include <linux/fb.h>
  35#include <asm/types.h>
  36#include "fb_draw.h"
  37
  38#define DEBUG
  39
  40#ifdef DEBUG
  41#define DPRINTK(fmt, args...) printk(KERN_DEBUG "%s: " fmt,__func__,## args)
  42#else
  43#define DPRINTK(fmt, args...)
  44#endif
  45
  46static const u32 cfb_tab8_be[] = {
  47    0x00000000,0x000000ff,0x0000ff00,0x0000ffff,
  48    0x00ff0000,0x00ff00ff,0x00ffff00,0x00ffffff,
  49    0xff000000,0xff0000ff,0xff00ff00,0xff00ffff,
  50    0xffff0000,0xffff00ff,0xffffff00,0xffffffff
  51};
  52
  53static const u32 cfb_tab8_le[] = {
  54    0x00000000,0xff000000,0x00ff0000,0xffff0000,
  55    0x0000ff00,0xff00ff00,0x00ffff00,0xffffff00,
  56    0x000000ff,0xff0000ff,0x00ff00ff,0xffff00ff,
  57    0x0000ffff,0xff00ffff,0x00ffffff,0xffffffff
  58};
  59
  60static const u32 cfb_tab16_be[] = {
  61    0x00000000, 0x0000ffff, 0xffff0000, 0xffffffff
  62};
  63
  64static const u32 cfb_tab16_le[] = {
  65    0x00000000, 0xffff0000, 0x0000ffff, 0xffffffff
  66};
  67
  68static const u32 cfb_tab32[] = {
  69        0x00000000, 0xffffffff
  70};
  71
  72#define FB_WRITEL fb_writel
  73#define FB_READL  fb_readl
  74
  75static inline void color_imageblit(const struct fb_image *image, 
  76                                   struct fb_info *p, u8 __iomem *dst1, 
  77                                   u32 start_index,
  78                                   u32 pitch_index)
  79{
  80        /* Draw the penguin */
  81        u32 __iomem *dst, *dst2;
  82        u32 color = 0, val, shift;
  83        int i, n, bpp = p->var.bits_per_pixel;
  84        u32 null_bits = 32 - bpp;
  85        u32 *palette = (u32 *) p->pseudo_palette;
  86        const u8 *src = image->data;
  87        u32 bswapmask = fb_compute_bswapmask(p);
  88
  89        dst2 = (u32 __iomem *) dst1;
  90        for (i = image->height; i--; ) {
  91                n = image->width;
  92                dst = (u32 __iomem *) dst1;
  93                shift = 0;
  94                val = 0;
  95                
  96                if (start_index) {
  97                        u32 start_mask = ~fb_shifted_pixels_mask_u32(p,
  98                                                start_index, bswapmask);
  99                        val = FB_READL(dst) & start_mask;
 100                        shift = start_index;
 101                }
 102                while (n--) {
 103                        if (p->fix.visual == FB_VISUAL_TRUECOLOR ||
 104                            p->fix.visual == FB_VISUAL_DIRECTCOLOR )
 105                                color = palette[*src];
 106                        else
 107                                color = *src;
 108                        color <<= FB_LEFT_POS(p, bpp);
 109                        val |= FB_SHIFT_HIGH(p, color, shift ^ bswapmask);
 110                        if (shift >= null_bits) {
 111                                FB_WRITEL(val, dst++);
 112        
 113                                val = (shift == null_bits) ? 0 : 
 114                                        FB_SHIFT_LOW(p, color, 32 - shift);
 115                        }
 116                        shift += bpp;
 117                        shift &= (32 - 1);
 118                        src++;
 119                }
 120                if (shift) {
 121                        u32 end_mask = fb_shifted_pixels_mask_u32(p, shift,
 122                                                bswapmask);
 123
 124                        FB_WRITEL((FB_READL(dst) & end_mask) | val, dst);
 125                }
 126                dst1 += p->fix.line_length;
 127                if (pitch_index) {
 128                        dst2 += p->fix.line_length;
 129                        dst1 = (u8 __iomem *)((long __force)dst2 & ~(sizeof(u32) - 1));
 130
 131                        start_index += pitch_index;
 132                        start_index &= 32 - 1;
 133                }
 134        }
 135}
 136
 137static inline void slow_imageblit(const struct fb_image *image, struct fb_info *p, 
 138                                  u8 __iomem *dst1, u32 fgcolor,
 139                                  u32 bgcolor, 
 140                                  u32 start_index,
 141                                  u32 pitch_index)
 142{
 143        u32 shift, color = 0, bpp = p->var.bits_per_pixel;
 144        u32 __iomem *dst, *dst2;
 145        u32 val, pitch = p->fix.line_length;
 146        u32 null_bits = 32 - bpp;
 147        u32 spitch = (image->width+7)/8;
 148        const u8 *src = image->data, *s;
 149        u32 i, j, l;
 150        u32 bswapmask = fb_compute_bswapmask(p);
 151
 152        dst2 = (u32 __iomem *) dst1;
 153        fgcolor <<= FB_LEFT_POS(p, bpp);
 154        bgcolor <<= FB_LEFT_POS(p, bpp);
 155
 156        for (i = image->height; i--; ) {
 157                shift = val = 0;
 158                l = 8;
 159                j = image->width;
 160                dst = (u32 __iomem *) dst1;
 161                s = src;
 162
 163                /* write leading bits */
 164                if (start_index) {
 165                        u32 start_mask = ~fb_shifted_pixels_mask_u32(p,
 166                                                start_index, bswapmask);
 167                        val = FB_READL(dst) & start_mask;
 168                        shift = start_index;
 169                }
 170
 171                while (j--) {
 172                        l--;
 173                        color = (*s & (1 << l)) ? fgcolor : bgcolor;
 174                        val |= FB_SHIFT_HIGH(p, color, shift ^ bswapmask);
 175                        
 176                        /* Did the bitshift spill bits to the next long? */
 177                        if (shift >= null_bits) {
 178                                FB_WRITEL(val, dst++);
 179                                val = (shift == null_bits) ? 0 :
 180                                        FB_SHIFT_LOW(p, color, 32 - shift);
 181                        }
 182                        shift += bpp;
 183                        shift &= (32 - 1);
 184                        if (!l) { l = 8; s++; };
 185                }
 186
 187                /* write trailing bits */
 188                if (shift) {
 189                        u32 end_mask = fb_shifted_pixels_mask_u32(p, shift,
 190                                                bswapmask);
 191
 192                        FB_WRITEL((FB_READL(dst) & end_mask) | val, dst);
 193                }
 194                
 195                dst1 += pitch;
 196                src += spitch;  
 197                if (pitch_index) {
 198                        dst2 += pitch;
 199                        dst1 = (u8 __iomem *)((long __force)dst2 & ~(sizeof(u32) - 1));
 200                        start_index += pitch_index;
 201                        start_index &= 32 - 1;
 202                }
 203                
 204        }
 205}
 206
 207/*
 208 * fast_imageblit - optimized monochrome color expansion
 209 *
 210 * Only if:  bits_per_pixel == 8, 16, or 32
 211 *           image->width is divisible by pixel/dword (ppw);
 212 *           fix->line_legth is divisible by 4;
 213 *           beginning and end of a scanline is dword aligned
 214 */
 215static inline void fast_imageblit(const struct fb_image *image, struct fb_info *p, 
 216                                  u8 __iomem *dst1, u32 fgcolor, 
 217                                  u32 bgcolor) 
 218{
 219        u32 fgx = fgcolor, bgx = bgcolor, bpp = p->var.bits_per_pixel;
 220        u32 ppw = 32/bpp, spitch = (image->width + 7)/8;
 221        u32 bit_mask, end_mask, eorx, shift;
 222        const char *s = image->data, *src;
 223        u32 __iomem *dst;
 224        const u32 *tab = NULL;
 225        int i, j, k;
 226
 227        switch (bpp) {
 228        case 8:
 229                tab = fb_be_math(p) ? cfb_tab8_be : cfb_tab8_le;
 230                break;
 231        case 16:
 232                tab = fb_be_math(p) ? cfb_tab16_be : cfb_tab16_le;
 233                break;
 234        case 32:
 235        default:
 236                tab = cfb_tab32;
 237                break;
 238        }
 239
 240        for (i = ppw-1; i--; ) {
 241                fgx <<= bpp;
 242                bgx <<= bpp;
 243                fgx |= fgcolor;
 244                bgx |= bgcolor;
 245        }
 246        
 247        bit_mask = (1 << ppw) - 1;
 248        eorx = fgx ^ bgx;
 249        k = image->width/ppw;
 250
 251        for (i = image->height; i--; ) {
 252                dst = (u32 __iomem *) dst1, shift = 8; src = s;
 253                
 254                for (j = k; j--; ) {
 255                        shift -= ppw;
 256                        end_mask = tab[(*src >> shift) & bit_mask];
 257                        FB_WRITEL((end_mask & eorx)^bgx, dst++);
 258                        if (!shift) { shift = 8; src++; }               
 259                }
 260                dst1 += p->fix.line_length;
 261                s += spitch;
 262        }
 263}       
 264        
 265void cfb_imageblit(struct fb_info *p, const struct fb_image *image)
 266{
 267        u32 fgcolor, bgcolor, start_index, bitstart, pitch_index = 0;
 268        u32 bpl = sizeof(u32), bpp = p->var.bits_per_pixel;
 269        u32 width = image->width;
 270        u32 dx = image->dx, dy = image->dy;
 271        u8 __iomem *dst1;
 272
 273        if (p->state != FBINFO_STATE_RUNNING)
 274                return;
 275
 276        bitstart = (dy * p->fix.line_length * 8) + (dx * bpp);
 277        start_index = bitstart & (32 - 1);
 278        pitch_index = (p->fix.line_length & (bpl - 1)) * 8;
 279
 280        bitstart /= 8;
 281        bitstart &= ~(bpl - 1);
 282        dst1 = p->screen_base + bitstart;
 283
 284        if (p->fbops->fb_sync)
 285                p->fbops->fb_sync(p);
 286
 287        if (image->depth == 1) {
 288                if (p->fix.visual == FB_VISUAL_TRUECOLOR ||
 289                    p->fix.visual == FB_VISUAL_DIRECTCOLOR) {
 290                        fgcolor = ((u32*)(p->pseudo_palette))[image->fg_color];
 291                        bgcolor = ((u32*)(p->pseudo_palette))[image->bg_color];
 292                } else {
 293                        fgcolor = image->fg_color;
 294                        bgcolor = image->bg_color;
 295                }       
 296                
 297                if (32 % bpp == 0 && !start_index && !pitch_index && 
 298                    ((width & (32/bpp-1)) == 0) &&
 299                    bpp >= 8 && bpp <= 32)                      
 300                        fast_imageblit(image, p, dst1, fgcolor, bgcolor);
 301                else 
 302                        slow_imageblit(image, p, dst1, fgcolor, bgcolor,
 303                                        start_index, pitch_index);
 304        } else
 305                color_imageblit(image, p, dst1, start_index, pitch_index);
 306}
 307
 308EXPORT_SYMBOL(cfb_imageblit);
 309
 310MODULE_AUTHOR("James Simmons <jsimmons@users.sf.net>");
 311MODULE_DESCRIPTION("Generic software accelerated imaging drawing");
 312MODULE_LICENSE("GPL");
 313
 314
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