drivers/video/cfbimgblt.c

   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/config.h>
  33 #include <linux/module.h>
  34 #include <linux/string.h>
  35 #include <linux/fb.h>
  36 #include <asm/types.h>
  37
  38 #define DEBUG
  39
  40 #ifdef DEBUG
  41 #define DPRINTK(fmt, args...) printk(KERN_DEBUG "%s: " fmt,__FUNCTION__,## args)
  42 #else
  43 #define DPRINTK(fmt, args...)
  44 #endif
  45
  46 static u32 cfb_tab8[] = {
  47 #if defined(__BIG_ENDIAN)
  48     0x00000000,0x000000ff,0x0000ff00,0x0000ffff,
  49     0x00ff0000,0x00ff00ff,0x00ffff00,0x00ffffff,
  50     0xff000000,0xff0000ff,0xff00ff00,0xff00ffff,
  51     0xffff0000,0xffff00ff,0xffffff00,0xffffffff
  52 #elif defined(__LITTLE_ENDIAN)
  53     0x00000000,0xff000000,0x00ff0000,0xffff0000,
  54     0x0000ff00,0xff00ff00,0x00ffff00,0xffffff00,
  55     0x000000ff,0xff0000ff,0x00ff00ff,0xffff00ff,
  56     0x0000ffff,0xff00ffff,0x00ffffff,0xffffffff
  57 #else
  58 #error FIXME: No endianness??
  59 #endif
  60 };
  61
  62 static u32 cfb_tab16[] = {
  63 #if defined(__BIG_ENDIAN)
  64     0x00000000, 0x0000ffff, 0xffff0000, 0xffffffff
  65 #elif defined(__LITTLE_ENDIAN)
  66     0x00000000, 0xffff0000, 0x0000ffff, 0xffffffff
  67 #else
  68 #error FIXME: No endianness??
  69 #endif
  70 };
  71
  72 static u32 cfb_tab32[] = {
  73         0x00000000, 0xffffffff
  74 };
  75
  76 #if BITS_PER_LONG == 32
  77 #define FB_WRITEL fb_writel
  78 #define FB_READL  fb_readl
  79 #else
  80 #define FB_WRITEL fb_writeq
  81 #define FB_READL  fb_readq
  82 #endif
  83
  84 #if defined (__BIG_ENDIAN)
  85 #define LEFT_POS(bpp)          (BITS_PER_LONG - bpp)
  86 #define NEXT_POS(pos, bpp)     ((pos) -= (bpp))
  87 #define SHIFT_HIGH(val, bits)  ((val) >> (bits))
  88 #define SHIFT_LOW(val, bits)   ((val) << (bits))
  89 #else
  90 #define LEFT_POS(bpp)          (0)
  91 #define NEXT_POS(pos, bpp)     ((pos) += (bpp))
  92 #define SHIFT_HIGH(val, bits)  ((val) << (bits))
  93 #define SHIFT_LOW(val, bits)   ((val) >> (bits))
  94 #endif
  95
  96 static inline void color_imageblit(struct fb_image *image, struct fb_info *p,
  97                                    u8 *dst1, unsigned long start_index,
  98                                    unsigned long pitch_index)
  99 {
 100         /* Draw the penguin */
 101         unsigned long *dst, *dst2, color = 0, val, shift;
 102         int i, n, bpp = p->var.bits_per_pixel;
 103         unsigned long null_bits = BITS_PER_LONG - bpp;
 104         u32 *palette = (u32 *) p->pseudo_palette;
 105         u8 *src = image->data;
 106
 107         dst2 = (unsigned long *) dst1;
 108         for (i = image->height; i--; ) {
 109                 n = image->width;
 110                 dst = (unsigned long *) dst1;
 111                 shift = 0;
 112                 val = 0;
 113
 114                 if (start_index) {
 115                         unsigned long start_mask = ~(SHIFT_HIGH(~0UL,
 116                                                                 start_index));
 117                         val = FB_READL(dst) & start_mask;
 118                         shift = start_index;
 119                 }
 120                 while (n--) {
 121                         if (p->fix.visual == FB_VISUAL_TRUECOLOR ||
 122                             p->fix.visual == FB_VISUAL_DIRECTCOLOR )
 123                                 color = palette[*src];
 124                         else
 125                                 color = *src;
 126                         color <<= LEFT_POS(bpp);
 127                         val |= SHIFT_HIGH(color, shift);
 128                         if (shift >= null_bits) {
 129                                 FB_WRITEL(val, dst++);
 130
 131                                 val = (shift == null_bits) ? 0 :
 132                                         SHIFT_LOW(color,BITS_PER_LONG - shift);
 133                         }
 134                         shift += bpp;
 135                         shift &= (BITS_PER_LONG - 1);
 136                         src++;
 137                 }
 138                 if (shift) {
 139                         unsigned long  end_mask = SHIFT_HIGH(~0UL, shift);
 140
 141                         FB_WRITEL((FB_READL(dst) & end_mask) | val, dst);
 142                 }
 143                 dst1 += p->fix.line_length;
 144                 if (pitch_index) {
 145                         dst2 += p->fix.line_length;
 146                         dst1 = (char *) dst2;
 147                         (unsigned long) dst1 &= ~(sizeof(unsigned long) - 1);
 148
 149                         start_index += pitch_index;
 150                         start_index &= BITS_PER_LONG - 1;
 151                 }
 152         }
 153 }
 154
 155 static inline void slow_imageblit(struct fb_image *image, struct fb_info *p,
 156                                   u8 *dst1, unsigned long fgcolor,
 157                                   unsigned long bgcolor,
 158                                   unsigned long start_index,
 159                                   unsigned long pitch_index)
 160 {
 161         unsigned long shift, color = 0, bpp = p->var.bits_per_pixel;
 162         unsigned long *dst, *dst2, val, pitch = p->fix.line_length;
 163         unsigned long null_bits = BITS_PER_LONG - bpp;
 164         unsigned long spitch = (image->width+7)/8;
 165         u8 *src = image->data, *s;
 166         unsigned long i, j, l;
 167
 168         dst2 = (unsigned long *) dst1;
 169
 170         for (i = image->height; i--; ) {
 171                 shift = val = 0;
 172                 l = 8;
 173                 j = image->width;
 174                 dst = (unsigned long *) dst1;
 175                 s = src;
 176
 177                 /* write leading bits */
 178                 if (start_index) {
 179                         unsigned long start_mask = ~(SHIFT_HIGH(~0UL,
 180                                                                 start_index));
 181                         val = FB_READL(dst) & start_mask;
 182                         shift = start_index;
 183                 }
 184
 185                 while (j--) {
 186                         l--;
 187                         color = (*s & (1 << l)) ? fgcolor : bgcolor;
 188                         color <<= LEFT_POS(bpp);
 189                         val |= SHIFT_HIGH(color, shift);
 190
 191                         /* Did the bitshift spill bits to the next long? */
 192                         if (shift >= null_bits) {
 193                                 FB_WRITEL(val, dst++);
 194                                 val = (shift == null_bits) ? 0 :
 195                                          SHIFT_LOW(color,BITS_PER_LONG - shift);
 196                         }
 197                         shift += bpp;
 198                         shift &= (BITS_PER_LONG - 1);
 199                         if (!l) { l = 8; s++; };
 200                 }
 201
 202                 /* write trailing bits */
 203                 if (shift) {
 204                         unsigned long end_mask = SHIFT_HIGH(~0UL, shift);
 205
 206                         FB_WRITEL((FB_READL(dst) & end_mask) | val, dst);
 207                 }
 208
 209                 dst1 += pitch;
 210                 src += spitch;
 211                 if (pitch_index) {
 212                         dst2 += pitch;
 213                         dst1 = (char *) dst2;
 214                         (unsigned long) dst1 &= ~(sizeof(unsigned long) - 1);
 215
 216                         start_index += pitch_index;
 217                         start_index &= BITS_PER_LONG - 1;
 218                 }
 219
 220         }
 221 }
 222
 223 /*
 224  * fast_imageblit - optimized monochrome color expansion
 225  *
 226  * Only if:  bits_per_pixel == 8, 16, or 32
 227  *           image->width is divisible by pixel/dword (ppw);
 228  *           fix->line_legth is divisible by 4;
 229  *           beginning and end of a scanline is dword aligned
 230  */
 231 static inline void fast_imageblit(struct fb_image *image, struct fb_info *p,
 232                                   u8 *dst1, unsigned long fgcolor,
 233                                   unsigned long bgcolor)
 234 {
 235         unsigned long fgx = fgcolor, bgx = bgcolor, bpp = p->var.bits_per_pixel;
 236         unsigned long ppw = BITS_PER_LONG/bpp, spitch = (image->width + 7)/8;
 237         unsigned long bit_mask, end_mask, eorx, shift;
 238         char *s = image->data, *src;
 239         unsigned long *dst;
 240         u32 *tab = NULL;
 241         int i, j, k;
 242
 243         switch (bpp) {
 244         case 8:
 245                 tab = cfb_tab8;
 246                 break;
 247         case 16:
 248                 tab = cfb_tab16;
 249                 break;
 250         case 32:
 251                 tab = cfb_tab32;
 252                 break;
 253         }
 254
 255         for (i = ppw-1; i--; ) {
 256                 fgx <<= bpp;
 257                 bgx <<= bpp;
 258                 fgx |= fgcolor;
 259                 bgx |= bgcolor;
 260         }
 261
 262         bit_mask = (1 << ppw) - 1;
 263         eorx = fgx ^ bgx;
 264         k = image->width/ppw;
 265
 266         for (i = image->height; i--; ) {
 267                 dst = (unsigned long *) dst1, shift = 8; src = s;
 268
 269                 for (j = k; j--; ) {
 270                         shift -= ppw;
 271                         end_mask = tab[(*src >> shift) & bit_mask];
 272                         FB_WRITEL((end_mask & eorx)^bgx, dst++);
 273                         if (!shift) { shift = 8; src++; }
 274                 }
 275                 dst1 += p->fix.line_length;
 276                 s += spitch;
 277         }
 278 }
 279
 280 void cfb_imageblit(struct fb_info *p, struct fb_image *image)
 281 {
 282         unsigned long fgcolor, bgcolor, start_index, bitstart, pitch_index = 0;
 283         unsigned long bpl = sizeof(unsigned long), bpp = p->var.bits_per_pixel;
 284         int x2, y2, vxres, vyres;
 285         u8 *dst1;
 286
 287         vxres = p->var.xres_virtual;
 288         vyres = p->var.yres_virtual;
 289         /*
 290          * We could use hardware clipping but on many cards you get around
 291          * hardware clipping by writing to framebuffer directly like we are
 292          * doing here.
 293          */
 294         if (image->dx > vxres || image->dy > vyres)
 295                 return;
 296
 297         x2 = image->dx + image->width;
 298         y2 = image->dy + image->height;
 299         image->dx = image->dx > 0 ? image->dx : 0;
 300         image->dy = image->dy > 0 ? image->dy : 0;
 301         x2 = x2 < vxres ? x2 : vxres;
 302         y2 = y2 < vyres ? y2 : vyres;
 303         image->width  = x2 - image->dx;
 304         image->height = y2 - image->dy;
 305
 306         bitstart = (image->dy * p->fix.line_length * 8) + (image->dx * bpp);
 307         start_index = bitstart & (BITS_PER_LONG - 1);
 308         pitch_index = (p->fix.line_length & (bpl - 1)) * 8;
 309
 310         bitstart /= 8;
 311         bitstart &= ~(bpl - 1);
 312         dst1 = p->screen_base + bitstart;
 313
 314         if (p->fbops->fb_sync)
 315                 p->fbops->fb_sync(p);
 316
 317         if (image->depth == 1) {
 318                 if (p->fix.visual == FB_VISUAL_TRUECOLOR ||
 319                     p->fix.visual == FB_VISUAL_DIRECTCOLOR) {
 320                         fgcolor = ((u32*)(p->pseudo_palette))[image->fg_color];
 321                         bgcolor = ((u32*)(p->pseudo_palette))[image->bg_color];
 322                 } else {
 323                         fgcolor = image->fg_color;
 324                         bgcolor = image->bg_color;
 325                 }
 326
 327                 if (BITS_PER_LONG % bpp == 0 && !start_index && !pitch_index &&
 328                     ((image->width & (BITS_PER_LONG/bpp-1)) == 0) &&
 329                     bpp >= 8 && bpp <= 32)
 330                         fast_imageblit(image, p, dst1, fgcolor, bgcolor);
 331                 else
 332                         slow_imageblit(image, p, dst1, fgcolor, bgcolor, start_index, pitch_index);
 333         }
 334         else if (image->depth == bpp)
 335                 color_imageblit(image, p, dst1, start_index, pitch_index);
 336 }
 337
 338 EXPORT_SYMBOL(cfb_imageblit);
 339
 340 MODULE_AUTHOR("James Simmons <jsimmons@users.sf.net>");
 341 MODULE_DESCRIPTION("Generic software accelerated imaging drawing");
 342 MODULE_LICENSE("GPL");
 343