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             return -1;
 102         if (!(cmap->green = kmalloc(size, GFP_ATOMIC)))
 103             return -1;
 104         if (!(cmap->blue = kmalloc(size, GFP_ATOMIC)))
 105             return -1;
 106         if (transp) {
 107             if (!(cmap->transp = kmalloc(size, GFP_ATOMIC)))
 108                 return -1;
 109         } else
 110             cmap->transp = NULL;
 111     }
 112     cmap->start = 0;
 113     cmap->len = len;
 114     fb_copy_cmap(fb_default_cmap(len), cmap, 0);
 115     return 0;
 116 }
 117
 118 /**
 119  *      fb_dealloc_cmap - deallocate a colormap
 120  *      @cmap: frame buffer colormap structure
 121  *
 122  *      Deallocates a colormap that was previously allocated with
 123  *      fb_alloc_cmap().
 124  *
 125  */
 126
 127 void fb_dealloc_cmap(struct fb_cmap *cmap)
 128 {
 129         if (cmap->red)
 130                 kfree(cmap->red);
 131         if (cmap->green)
 132                 kfree(cmap->green);
 133         if (cmap->blue)
 134                 kfree(cmap->blue);
 135         if (cmap->transp)
 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  *      @fsfromto: determine copy method
 147  *
 148  *      Copy contents of colormap from @from to @to.
 149  *
 150  *      @fsfromto accepts the following integer parameters:
 151  *      0: memcpy function
 152  *      1: copy_from_user() function to copy from userspace
 153  *      2: copy_to_user() function to copy to userspace
 154  *
 155  */
 156
 157 int fb_copy_cmap(struct fb_cmap *from, struct fb_cmap *to, int fsfromto)
 158 {
 159     int tooff = 0, fromoff = 0;
 160     int size;
 161
 162     if (to->start > from->start)
 163         fromoff = to->start-from->start;
 164     else
 165         tooff = from->start-to->start;
 166     size = to->len-tooff;
 167     if (size > (int) (from->len - fromoff))
 168         size = from->len-fromoff;
 169     if (size <= 0)
 170         return -EINVAL;
 171     size *= sizeof(u16);
 172
 173     switch (fsfromto) {
 174     case 0:
 175         memcpy(to->red+tooff, from->red+fromoff, size);
 176         memcpy(to->green+tooff, from->green+fromoff, size);
 177         memcpy(to->blue+tooff, from->blue+fromoff, size);
 178         if (from->transp && to->transp)
 179             memcpy(to->transp+tooff, from->transp+fromoff, size);
 180         break;
 181     case 1:
 182         if (copy_from_user(to->red+tooff, from->red+fromoff, size))
 183                 return -EFAULT;
 184         if (copy_from_user(to->green+tooff, from->green+fromoff, size))
 185                 return -EFAULT;
 186         if (copy_from_user(to->blue+tooff, from->blue+fromoff, size))
 187                 return -EFAULT;
 188         if (from->transp && to->transp)
 189             if (copy_from_user(to->transp+tooff, from->transp+fromoff, size))
 190                     return -EFAULT;
 191         break;
 192     case 2:
 193         if (copy_to_user(to->red+tooff, from->red+fromoff, size))
 194                 return -EFAULT;
 195         if (copy_to_user(to->green+tooff, from->green+fromoff, size))
 196                 return -EFAULT;
 197         if (copy_to_user(to->blue+tooff, from->blue+fromoff, size))
 198                 return -EFAULT;
 199         if (from->transp && to->transp)
 200                 if (copy_to_user(to->transp+tooff, from->transp+fromoff, size))
 201                         return -EFAULT;
 202         break;
 203     }
 204     return 0;
 205 }
 206
 207 /**
 208  *      fb_set_cmap - set the colormap
 209  *      @cmap: frame buffer colormap structure
 210  *      @kspc: boolean, 0 copy local, 1 get_user() function
 211  *      @info: frame buffer info structure
 212  *
 213  *      Sets the colormap @cmap for a screen of device @info.
 214  *
 215  *      Returns negative errno on error, or zero on success.
 216  *
 217  */
 218
 219 int fb_set_cmap(struct fb_cmap *cmap, int kspc, struct fb_info *info)
 220 {
 221     int i, start;
 222     u16 *red, *green, *blue, *transp;
 223     u_int hred, hgreen, hblue, htransp;
 224
 225     red = cmap->red;
 226     green = cmap->green;
 227     blue = cmap->blue;
 228     transp = cmap->transp;
 229     start = cmap->start;
 230
 231     if (start < 0 || !info->fbops->fb_setcolreg)
 232         return -EINVAL;
 233     for (i = 0; i < cmap->len; i++) {
 234         if (kspc) {
 235             hred = *red;
 236             hgreen = *green;
 237             hblue = *blue;
 238             htransp = transp ? *transp : 0xffff;
 239         } else {
 240             get_user(hred, red);
 241             get_user(hgreen, green);
 242             get_user(hblue, blue);
 243             if (transp)
 244                 get_user(htransp, transp);
 245             else
 246                 htransp = 0xffff;
 247         }
 248         red++;
 249         green++;
 250         blue++;
 251         if (transp)
 252             transp++;
 253         if (info->fbops->fb_setcolreg(start++, hred, hgreen, hblue, htransp, info))
 254             return 0;
 255     }
 256     return 0;
 257 }
 258
 259
 260 /**
 261  *      fb_default_cmap - get default colormap
 262  *      @len: size of palette for a depth
 263  *
 264  *      Gets the default colormap for a specific screen depth.  @len
 265  *      is the size of the palette for a particular screen depth.
 266  *
 267  *      Returns pointer to a frame buffer colormap structure.
 268  *
 269  */
 270
 271 struct fb_cmap *fb_default_cmap(int len)
 272 {
 273     if (len <= 2)
 274         return &default_2_colors;
 275     if (len <= 4)
 276         return &default_4_colors;
 277     if (len <= 8)
 278         return &default_8_colors;
 279     return &default_16_colors;
 280 }
 281
 282
 283 /**
 284  *      fb_invert_cmaps - invert all defaults colormaps
 285  *
 286  *      Invert all default colormaps.
 287  *
 288  */
 289
 290 void fb_invert_cmaps(void)
 291 {
 292     u_int i;
 293
 294     for (i = 0; i < 2; i++) {
 295         red2[i] = ~red2[i];
 296         green2[i] = ~green2[i];
 297         blue2[i] = ~blue2[i];
 298     }
 299     for (i = 0; i < 4; i++) {
 300         red4[i] = ~red4[i];
 301         green4[i] = ~green4[i];
 302         blue4[i] = ~blue4[i];
 303     }
 304     for (i = 0; i < 8; i++) {
 305         red8[i] = ~red8[i];
 306         green8[i] = ~green8[i];
 307         blue8[i] = ~blue8[i];
 308     }
 309     for (i = 0; i < 16; i++) {
 310         red16[i] = ~red16[i];
 311         green16[i] = ~green16[i];
 312         blue16[i] = ~blue16[i];
 313     }
 314 }
 315
 316
 317     /*
 318      *  Visible symbols for modules
 319      */
 320
 321 EXPORT_SYMBOL(fb_alloc_cmap);
 322 EXPORT_SYMBOL(fb_dealloc_cmap);
 323 EXPORT_SYMBOL(fb_copy_cmap);
 324 EXPORT_SYMBOL(fb_set_cmap);
 325 EXPORT_SYMBOL(fb_default_cmap);
 326 EXPORT_SYMBOL(fb_invert_cmaps);