drivers/video/fbcmap.c

   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                 return -EINVAL;
 227         for (i = 0; i < cmap->len; i++) {
 228                 hred = *red++;
 229                 hgreen = *green++;
 230                 hblue = *blue++;
 231                 if (transp)
 232                         htransp = *transp++;
 233                 if (info->fbops->fb_setcolreg(start++,
 234                                               hred, hgreen, hblue, htransp,
 235                                               info))
 236                         break;
 237         }
 238         return 0;
 239 }
 240
 241 int fb_set_user_cmap(struct fb_cmap_user *cmap, struct fb_info *info)
 242 {
 243         int i, start;
 244         u16 __user *red, *green, *blue, *transp;
 245         u_int hred, hgreen, hblue, htransp = 0xffff;
 246
 247         red = cmap->red;
 248         green = cmap->green;
 249         blue = cmap->blue;
 250         transp = cmap->transp;
 251         start = cmap->start;
 252
 253         if (start < 0 || !info->fbops->fb_setcolreg)
 254                 return -EINVAL;
 255         for (i = 0; i < cmap->len; i++, red++, blue++, green++) {
 256                 if (get_user(hred, red) ||
 257                     get_user(hgreen, green) ||
 258                     get_user(hblue, blue) ||
 259                     (transp && get_user(htransp, transp)))
 260                         return -EFAULT;
 261                 if (info->fbops->fb_setcolreg(start++,
 262                                               hred, hgreen, hblue, htransp,
 263                                               info))
 264                         return 0;
 265                 if (transp)
 266                         transp++;
 267         }
 268         return 0;
 269 }
 270
 271 /**
 272  *      fb_default_cmap - get default colormap
 273  *      @len: size of palette for a depth
 274  *
 275  *      Gets the default colormap for a specific screen depth.  @len
 276  *      is the size of the palette for a particular screen depth.
 277  *
 278  *      Returns pointer to a frame buffer colormap structure.
 279  *
 280  */
 281
 282 struct fb_cmap *fb_default_cmap(int len)
 283 {
 284     if (len <= 2)
 285         return &default_2_colors;
 286     if (len <= 4)
 287         return &default_4_colors;
 288     if (len <= 8)
 289         return &default_8_colors;
 290     return &default_16_colors;
 291 }
 292
 293
 294 /**
 295  *      fb_invert_cmaps - invert all defaults colormaps
 296  *
 297  *      Invert all default colormaps.
 298  *
 299  */
 300
 301 void fb_invert_cmaps(void)
 302 {
 303     u_int i;
 304
 305     for (i = 0; i < 2; i++) {
 306         red2[i] = ~red2[i];
 307         green2[i] = ~green2[i];
 308         blue2[i] = ~blue2[i];
 309     }
 310     for (i = 0; i < 4; i++) {
 311         red4[i] = ~red4[i];
 312         green4[i] = ~green4[i];
 313         blue4[i] = ~blue4[i];
 314     }
 315     for (i = 0; i < 8; i++) {
 316         red8[i] = ~red8[i];
 317         green8[i] = ~green8[i];
 318         blue8[i] = ~blue8[i];
 319     }
 320     for (i = 0; i < 16; i++) {
 321         red16[i] = ~red16[i];
 322         green16[i] = ~green16[i];
 323         blue16[i] = ~blue16[i];
 324     }
 325 }
 326
 327
 328     /*
 329      *  Visible symbols for modules
 330      */
 331
 332 EXPORT_SYMBOL(fb_alloc_cmap);
 333 EXPORT_SYMBOL(fb_dealloc_cmap);
 334 EXPORT_SYMBOL(fb_copy_cmap);
 335 EXPORT_SYMBOL(fb_set_cmap);
 336 EXPORT_SYMBOL(fb_default_cmap);
 337 EXPORT_SYMBOL(fb_invert_cmaps);