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   1 /*
   2  *  linux/drivers/video/fbcmap.c -- Colormap handling for frame buffer devices
   3  *
   4  *      Created 15 Jun 1997 by Geert Uytterhoeven
   5  *
   6  *      2001 - Documented with DocBook
   7  *      - Brad Douglas <brad@neruo.com>
   8  *
   9  *  This file is subject to the terms and conditions of the GNU General Public
  10  *  License.  See the file COPYING in the main directory of this archive for
  11  *  more details.
  12  */
  13
  14 #include <linux/string.h>
  15 #include <linux/module.h>
  16 #include <linux/tty.h>
  17 #include <linux/fb.h>
  18 #include <linux/slab.h>
  19
  20 #include <asm/uaccess.h>
  21
  22 static u16 red2[] = {
  23     0x0000, 0xaaaa
  24 };
  25 static u16 green2[] = {
  26     0x0000, 0xaaaa
  27 };
  28 static u16 blue2[] = {
  29     0x0000, 0xaaaa
  30 };
  31
  32 static u16 red4[] = {
  33     0x0000, 0xaaaa, 0x5555, 0xffff
  34 };
  35 static u16 green4[] = {
  36     0x0000, 0xaaaa, 0x5555, 0xffff
  37 };
  38 static u16 blue4[] = {
  39     0x0000, 0xaaaa, 0x5555, 0xffff
  40 };
  41
  42 static u16 red8[] = {
  43     0x0000, 0x0000, 0x0000, 0x0000, 0xaaaa, 0xaaaa, 0xaaaa, 0xaaaa
  44 };
  45 static u16 green8[] = {
  46     0x0000, 0x0000, 0xaaaa, 0xaaaa, 0x0000, 0x0000, 0x5555, 0xaaaa
  47 };
  48 static u16 blue8[] = {
  49     0x0000, 0xaaaa, 0x0000, 0xaaaa, 0x0000, 0xaaaa, 0x0000, 0xaaaa
  50 };
  51
  52 static u16 red16[] = {
  53     0x0000, 0x0000, 0x0000, 0x0000, 0xaaaa, 0xaaaa, 0xaaaa, 0xaaaa,
  54     0x5555, 0x5555, 0x5555, 0x5555, 0xffff, 0xffff, 0xffff, 0xffff
  55 };
  56 static u16 green16[] = {
  57     0x0000, 0x0000, 0xaaaa, 0xaaaa, 0x0000, 0x0000, 0x5555, 0xaaaa,
  58     0x5555, 0x5555, 0xffff, 0xffff, 0x5555, 0x5555, 0xffff, 0xffff
  59 };
  60 static u16 blue16[] = {
  61     0x0000, 0xaaaa, 0x0000, 0xaaaa, 0x0000, 0xaaaa, 0x0000, 0xaaaa,
  62     0x5555, 0xffff, 0x5555, 0xffff, 0x5555, 0xffff, 0x5555, 0xffff
  63 };
  64
  65 static struct fb_cmap default_2_colors = {
  66     0, 2, red2, green2, blue2, NULL
  67 };
  68 static struct fb_cmap default_8_colors = {
  69     0, 8, red8, green8, blue8, NULL
  70 };
  71 static struct fb_cmap default_4_colors = {
  72     0, 4, red4, green4, blue4, NULL
  73 };
  74 static struct fb_cmap default_16_colors = {
  75     0, 16, red16, green16, blue16, NULL
  76 };
  77
  78
  79 /**
  80  *      fb_alloc_cmap - allocate a colormap
  81  *      @cmap: frame buffer colormap structure
  82  *      @len: length of @cmap
  83  *      @transp: boolean, 1 if there is transparency, 0 otherwise
  84  *
  85  *      Allocates memory for a colormap @cmap.  @len is the
  86  *      number of entries in the palette.
  87  *
  88  *      Returns -1 errno on error, or zero on success.
  89  *
  90  */
  91
  92 int fb_alloc_cmap(struct fb_cmap *cmap, int len, int transp)
  93 {
  94     int size = len*sizeof(u16);
  95
  96     if (cmap->len != len) {
  97         fb_dealloc_cmap(cmap);
  98         if (!len)
  99             return 0;
 100         if (!(cmap->red = kmalloc(size, GFP_ATOMIC)))
 101             goto fail;
 102         if (!(cmap->green = kmalloc(size, GFP_ATOMIC)))
 103             goto fail;
 104         if (!(cmap->blue = kmalloc(size, GFP_ATOMIC)))
 105             goto fail;
 106         if (transp) {
 107             if (!(cmap->transp = kmalloc(size, GFP_ATOMIC)))
 108                 goto fail;
 109         } else
 110             cmap->transp = NULL;
 111     }
 112     cmap->start = 0;
 113     cmap->len = len;
 114     fb_copy_cmap(fb_default_cmap(len), cmap);
 115     return 0;
 116
 117 fail:
 118     fb_dealloc_cmap(cmap);
 119     return -1;
 120 }
 121
 122 /**
 123  *      fb_dealloc_cmap - deallocate a colormap
 124  *      @cmap: frame buffer colormap structure
 125  *
 126  *      Deallocates a colormap that was previously allocated with
 127  *      fb_alloc_cmap().
 128  *
 129  */
 130
 131 void fb_dealloc_cmap(struct fb_cmap *cmap)
 132 {
 133         kfree(cmap->red);
 134         kfree(cmap->green);
 135         kfree(cmap->blue);
 136         kfree(cmap->transp);
 137
 138         cmap->red = cmap->green = cmap->blue = cmap->transp = NULL;
 139         cmap->len = 0;
 140 }
 141
 142 /**
 143  *      fb_copy_cmap - copy a colormap
 144  *      @from: frame buffer colormap structure
 145  *      @to: frame buffer colormap structure
 146  *
 147  *      Copy contents of colormap from @from to @to.
 148  */
 149
 150 int fb_copy_cmap(struct fb_cmap *from, struct fb_cmap *to)
 151 {
 152         int tooff = 0, fromoff = 0;
 153         int size;
 154
 155         if (to->start > from->start)
 156                 fromoff = to->start - from->start;
 157         else
 158                 tooff = from->start - to->start;
 159         size = to->len - tooff;
 160         if (size > (int) (from->len - fromoff))
 161                 size = from->len - fromoff;
 162         if (size <= 0)
 163                 return -EINVAL;
 164         size *= sizeof(u16);
 165
 166         memcpy(to->red+tooff, from->red+fromoff, size);
 167         memcpy(to->green+tooff, from->green+fromoff, size);
 168         memcpy(to->blue+tooff, from->blue+fromoff, size);
 169         if (from->transp && to->transp)
 170                 memcpy(to->transp+tooff, from->transp+fromoff, size);
 171         return 0;
 172 }
 173
 174 int fb_cmap_to_user(struct fb_cmap *from, struct fb_cmap_user *to)
 175 {
 176         int tooff = 0, fromoff = 0;
 177         int size;
 178
 179         if (to->start > from->start)
 180                 fromoff = to->start - from->start;
 181         else
 182                 tooff = from->start - to->start;
 183         size = to->len - tooff;
 184         if (size > (int) (from->len - fromoff))
 185                 size = from->len - fromoff;
 186         if (size <= 0)
 187                 return -EINVAL;
 188         size *= sizeof(u16);
 189
 190         if (copy_to_user(to->red+tooff, from->red+fromoff, size))
 191                 return -EFAULT;
 192         if (copy_to_user(to->green+tooff, from->green+fromoff, size))
 193                 return -EFAULT;
 194         if (copy_to_user(to->blue+tooff, from->blue+fromoff, size))
 195                 return -EFAULT;
 196         if (from->transp && to->transp)
 197                 if (copy_to_user(to->transp+tooff, from->transp+fromoff, size))
 198                         return -EFAULT;
 199         return 0;
 200 }
 201
 202 /**
 203  *      fb_set_cmap - set the colormap
 204  *      @cmap: frame buffer colormap structure
 205  *      @info: frame buffer info structure
 206  *
 207  *      Sets the colormap @cmap for a screen of device @info.
 208  *
 209  *      Returns negative errno on error, or zero on success.
 210  *
 211  */
 212
 213 int fb_set_cmap(struct fb_cmap *cmap, struct fb_info *info)
 214 {
 215         int i, start;
 216         u16 *red, *green, *blue, *transp;
 217         u_int hred, hgreen, hblue, htransp = 0xffff;
 218
 219         red = cmap->red;
 220         green = cmap->green;
 221         blue = cmap->blue;
 222         transp = cmap->transp;
 223         start = cmap->start;
 224
 225         if (start < 0 || (!info->fbops->fb_setcolreg &&
 226                           !info->fbops->fb_setcmap))
 227                 return -EINVAL;
 228         if (info->fbops->fb_setcmap)
 229                 return info->fbops->fb_setcmap(cmap, info);
 230         for (i = 0; i < cmap->len; i++) {
 231                 hred = *red++;
 232                 hgreen = *green++;
 233                 hblue = *blue++;
 234                 if (transp)
 235                         htransp = *transp++;
 236                 if (info->fbops->fb_setcolreg(start++,
 237                                               hred, hgreen, hblue, htransp,
 238                                               info))
 239                         break;
 240         }
 241         return 0;
 242 }
 243
 244 int fb_set_user_cmap(struct fb_cmap_user *cmap, struct fb_info *info)
 245 {
 246         int i, start;
 247         u16 __user *red, *green, *blue, *transp;
 248         u_int hred, hgreen, hblue, htransp = 0xffff;
 249
 250         red = cmap->red;
 251         green = cmap->green;
 252         blue = cmap->blue;
 253         transp = cmap->transp;
 254         start = cmap->start;
 255
 256         if (start < 0 || (!info->fbops->fb_setcolreg &&
 257                           !info->fbops->fb_setcmap))
 258                 return -EINVAL;
 259
 260         /* If we can batch, do it */
 261         if (info->fbops->fb_setcmap && cmap->len > 1) {
 262                 struct fb_cmap umap;
 263                 int size = cmap->len * sizeof(u16);
 264                 int rc;
 265
 266                 memset(&umap, 0, sizeof(struct fb_cmap));
 267                 rc = fb_alloc_cmap(&umap, cmap->len, transp != NULL);
 268                 if (rc)
 269                         return rc;
 270                 if (copy_from_user(umap.red, red, size) ||
 271                     copy_from_user(umap.green, green, size) ||
 272                     copy_from_user(umap.blue, blue, size) ||
 273                     (transp && copy_from_user(umap.transp, transp, size))) {
 274                         rc = -EFAULT;
 275                 }
 276                 umap.start = start;
 277                 if (rc == 0)
 278                         rc = info->fbops->fb_setcmap(&umap, info);
 279                 fb_dealloc_cmap(&umap);
 280                 return rc;
 281         }
 282
 283         for (i = 0; i < cmap->len; i++, red++, blue++, green++) {
 284                 if (get_user(hred, red) ||
 285                     get_user(hgreen, green) ||
 286                     get_user(hblue, blue) ||
 287                     (transp && get_user(htransp, transp)))
 288                         return -EFAULT;
 289                 if (info->fbops->fb_setcolreg(start++,
 290                                               hred, hgreen, hblue, htransp,
 291                                               info))
 292                         return 0;
 293                 if (transp)
 294                         transp++;
 295         }
 296         return 0;
 297 }
 298
 299 /**
 300  *      fb_default_cmap - get default colormap
 301  *      @len: size of palette for a depth
 302  *
 303  *      Gets the default colormap for a specific screen depth.  @len
 304  *      is the size of the palette for a particular screen depth.
 305  *
 306  *      Returns pointer to a frame buffer colormap structure.
 307  *
 308  */
 309
 310 struct fb_cmap *fb_default_cmap(int len)
 311 {
 312     if (len <= 2)
 313         return &default_2_colors;
 314     if (len <= 4)
 315         return &default_4_colors;
 316     if (len <= 8)
 317         return &default_8_colors;
 318     return &default_16_colors;
 319 }
 320
 321
 322 /**
 323  *      fb_invert_cmaps - invert all defaults colormaps
 324  *
 325  *      Invert all default colormaps.
 326  *
 327  */
 328
 329 void fb_invert_cmaps(void)
 330 {
 331     u_int i;
 332
 333     for (i = 0; i < 2; i++) {
 334         red2[i] = ~red2[i];
 335         green2[i] = ~green2[i];
 336         blue2[i] = ~blue2[i];
 337     }
 338     for (i = 0; i < 4; i++) {
 339         red4[i] = ~red4[i];
 340         green4[i] = ~green4[i];
 341         blue4[i] = ~blue4[i];
 342     }
 343     for (i = 0; i < 8; i++) {
 344         red8[i] = ~red8[i];
 345         green8[i] = ~green8[i];
 346         blue8[i] = ~blue8[i];
 347     }
 348     for (i = 0; i < 16; i++) {
 349         red16[i] = ~red16[i];
 350         green16[i] = ~green16[i];
 351         blue16[i] = ~blue16[i];
 352     }
 353 }
 354
 355
 356     /*
 357      *  Visible symbols for modules
 358      */
 359
 360 EXPORT_SYMBOL(fb_alloc_cmap);
 361 EXPORT_SYMBOL(fb_dealloc_cmap);
 362 EXPORT_SYMBOL(fb_copy_cmap);
 363 EXPORT_SYMBOL(fb_set_cmap);
 364 EXPORT_SYMBOL(fb_default_cmap);
 365 EXPORT_SYMBOL(fb_invert_cmaps);