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/fb.h>
  17 #include <linux/slab.h>
  18 #include <linux/uaccess.h>
  19
  20 static u16 red2[] __read_mostly = {
  21     0x0000, 0xaaaa
  22 };
  23 static u16 green2[] __read_mostly = {
  24     0x0000, 0xaaaa
  25 };
  26 static u16 blue2[] __read_mostly = {
  27     0x0000, 0xaaaa
  28 };
  29
  30 static u16 red4[] __read_mostly = {
  31     0x0000, 0xaaaa, 0x5555, 0xffff
  32 };
  33 static u16 green4[] __read_mostly = {
  34     0x0000, 0xaaaa, 0x5555, 0xffff
  35 };
  36 static u16 blue4[] __read_mostly = {
  37     0x0000, 0xaaaa, 0x5555, 0xffff
  38 };
  39
  40 static u16 red8[] __read_mostly = {
  41     0x0000, 0x0000, 0x0000, 0x0000, 0xaaaa, 0xaaaa, 0xaaaa, 0xaaaa
  42 };
  43 static u16 green8[] __read_mostly = {
  44     0x0000, 0x0000, 0xaaaa, 0xaaaa, 0x0000, 0x0000, 0x5555, 0xaaaa
  45 };
  46 static u16 blue8[] __read_mostly = {
  47     0x0000, 0xaaaa, 0x0000, 0xaaaa, 0x0000, 0xaaaa, 0x0000, 0xaaaa
  48 };
  49
  50 static u16 red16[] __read_mostly = {
  51     0x0000, 0x0000, 0x0000, 0x0000, 0xaaaa, 0xaaaa, 0xaaaa, 0xaaaa,
  52     0x5555, 0x5555, 0x5555, 0x5555, 0xffff, 0xffff, 0xffff, 0xffff
  53 };
  54 static u16 green16[] __read_mostly = {
  55     0x0000, 0x0000, 0xaaaa, 0xaaaa, 0x0000, 0x0000, 0x5555, 0xaaaa,
  56     0x5555, 0x5555, 0xffff, 0xffff, 0x5555, 0x5555, 0xffff, 0xffff
  57 };
  58 static u16 blue16[] __read_mostly = {
  59     0x0000, 0xaaaa, 0x0000, 0xaaaa, 0x0000, 0xaaaa, 0x0000, 0xaaaa,
  60     0x5555, 0xffff, 0x5555, 0xffff, 0x5555, 0xffff, 0x5555, 0xffff
  61 };
  62
  63 static const struct fb_cmap default_2_colors = {
  64     .len=2, .red=red2, .green=green2, .blue=blue2
  65 };
  66 static const struct fb_cmap default_8_colors = {
  67     .len=8, .red=red8, .green=green8, .blue=blue8
  68 };
  69 static const struct fb_cmap default_4_colors = {
  70     .len=4, .red=red4, .green=green4, .blue=blue4
  71 };
  72 static const struct fb_cmap default_16_colors = {
  73     .len=16, .red=red16, .green=green16, .blue=blue16
  74 };
  75
  76
  77
  78 /**
  79  *      fb_alloc_cmap - allocate a colormap
  80  *      @cmap: frame buffer colormap structure
  81  *      @len: length of @cmap
  82  *      @transp: boolean, 1 if there is transparency, 0 otherwise
  83  *
  84  *      Allocates memory for a colormap @cmap.  @len is the
  85  *      number of entries in the palette.
  86  *
  87  *      Returns negative errno on error, or zero on success.
  88  *
  89  */
  90
  91 int fb_alloc_cmap(struct fb_cmap *cmap, int len, int transp)
  92 {
  93     int size = len*sizeof(u16);
  94
  95     if (cmap->len != len) {
  96         fb_dealloc_cmap(cmap);
  97         if (!len)
  98             return 0;
  99         if (!(cmap->red = kmalloc(size, GFP_ATOMIC)))
 100             goto fail;
 101         if (!(cmap->green = kmalloc(size, GFP_ATOMIC)))
 102             goto fail;
 103         if (!(cmap->blue = kmalloc(size, GFP_ATOMIC)))
 104             goto fail;
 105         if (transp) {
 106             if (!(cmap->transp = kmalloc(size, GFP_ATOMIC)))
 107                 goto fail;
 108         } else
 109             cmap->transp = NULL;
 110     }
 111     cmap->start = 0;
 112     cmap->len = len;
 113     fb_copy_cmap(fb_default_cmap(len), cmap);
 114     return 0;
 115
 116 fail:
 117     fb_dealloc_cmap(cmap);
 118     return -ENOMEM;
 119 }
 120
 121 /**
 122  *      fb_dealloc_cmap - deallocate a colormap
 123  *      @cmap: frame buffer colormap structure
 124  *
 125  *      Deallocates a colormap that was previously allocated with
 126  *      fb_alloc_cmap().
 127  *
 128  */
 129
 130 void fb_dealloc_cmap(struct fb_cmap *cmap)
 131 {
 132         kfree(cmap->red);
 133         kfree(cmap->green);
 134         kfree(cmap->blue);
 135         kfree(cmap->transp);
 136
 137         cmap->red = cmap->green = cmap->blue = cmap->transp = NULL;
 138         cmap->len = 0;
 139 }
 140
 141 /**
 142  *      fb_copy_cmap - copy a colormap
 143  *      @from: frame buffer colormap structure
 144  *      @to: frame buffer colormap structure
 145  *
 146  *      Copy contents of colormap from @from to @to.
 147  */
 148
 149 int fb_copy_cmap(const struct fb_cmap *from, struct fb_cmap *to)
 150 {
 151         int tooff = 0, fromoff = 0;
 152         int size;
 153
 154         if (to->start > from->start)
 155                 fromoff = to->start - from->start;
 156         else
 157                 tooff = from->start - to->start;
 158         size = to->len - tooff;
 159         if (size > (int) (from->len - fromoff))
 160                 size = from->len - fromoff;
 161         if (size <= 0)
 162                 return -EINVAL;
 163         size *= sizeof(u16);
 164
 165         memcpy(to->red+tooff, from->red+fromoff, size);
 166         memcpy(to->green+tooff, from->green+fromoff, size);
 167         memcpy(to->blue+tooff, from->blue+fromoff, size);
 168         if (from->transp && to->transp)
 169                 memcpy(to->transp+tooff, from->transp+fromoff, size);
 170         return 0;
 171 }
 172
 173 int fb_cmap_to_user(const struct fb_cmap *from, struct fb_cmap_user *to)
 174 {
 175         int tooff = 0, fromoff = 0;
 176         int size;
 177
 178         if (to->start > from->start)
 179                 fromoff = to->start - from->start;
 180         else
 181                 tooff = from->start - to->start;
 182         size = to->len - tooff;
 183         if (size > (int) (from->len - fromoff))
 184                 size = from->len - fromoff;
 185         if (size <= 0)
 186                 return -EINVAL;
 187         size *= sizeof(u16);
 188
 189         if (copy_to_user(to->red+tooff, from->red+fromoff, size))
 190                 return -EFAULT;
 191         if (copy_to_user(to->green+tooff, from->green+fromoff, size))
 192                 return -EFAULT;
 193         if (copy_to_user(to->blue+tooff, from->blue+fromoff, size))
 194                 return -EFAULT;
 195         if (from->transp && to->transp)
 196                 if (copy_to_user(to->transp+tooff, from->transp+fromoff, size))
 197                         return -EFAULT;
 198         return 0;
 199 }
 200
 201 /**
 202  *      fb_set_cmap - set the colormap
 203  *      @cmap: frame buffer colormap structure
 204  *      @info: frame buffer info structure
 205  *
 206  *      Sets the colormap @cmap for a screen of device @info.
 207  *
 208  *      Returns negative errno on error, or zero on success.
 209  *
 210  */
 211
 212 int fb_set_cmap(struct fb_cmap *cmap, struct fb_info *info)
 213 {
 214         int i, start, rc = 0;
 215         u16 *red, *green, *blue, *transp;
 216         u_int hred, hgreen, hblue, htransp = 0xffff;
 217
 218         red = cmap->red;
 219         green = cmap->green;
 220         blue = cmap->blue;
 221         transp = cmap->transp;
 222         start = cmap->start;
 223
 224         if (start < 0 || (!info->fbops->fb_setcolreg &&
 225                           !info->fbops->fb_setcmap))
 226                 return -EINVAL;
 227         if (info->fbops->fb_setcmap) {
 228                 rc = info->fbops->fb_setcmap(cmap, info);
 229         } else {
 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,
 238                                                       htransp, info))
 239                                 break;
 240                 }
 241         }
 242         if (rc == 0)
 243                 fb_copy_cmap(cmap, &info->cmap);
 244
 245         return rc;
 246 }
 247
 248 int fb_set_user_cmap(struct fb_cmap_user *cmap, struct fb_info *info)
 249 {
 250         int rc, size = cmap->len * sizeof(u16);
 251         struct fb_cmap umap;
 252
 253         memset(&umap, 0, sizeof(struct fb_cmap));
 254         rc = fb_alloc_cmap(&umap, cmap->len, cmap->transp != NULL);
 255         if (rc)
 256                 return rc;
 257         if (copy_from_user(umap.red, cmap->red, size) ||
 258             copy_from_user(umap.green, cmap->green, size) ||
 259             copy_from_user(umap.blue, cmap->blue, size) ||
 260             (cmap->transp && copy_from_user(umap.transp, cmap->transp, size))) {
 261                 rc = -EFAULT;
 262                 goto out;
 263         }
 264         umap.start = cmap->start;
 265         if (!lock_fb_info(info)) {
 266                 rc = -ENODEV;
 267                 goto out;
 268         }
 269         if (cmap->start < 0 || (!info->fbops->fb_setcolreg &&
 270                                 !info->fbops->fb_setcmap)) {
 271                 rc = -EINVAL;
 272                 goto out1;
 273         }
 274         rc = fb_set_cmap(&umap, info);
 275 out1:
 276         unlock_fb_info(info);
 277 out:
 278         fb_dealloc_cmap(&umap);
 279         return rc;
 280 }
 281
 282 /**
 283  *      fb_default_cmap - get default colormap
 284  *      @len: size of palette for a depth
 285  *
 286  *      Gets the default colormap for a specific screen depth.  @len
 287  *      is the size of the palette for a particular screen depth.
 288  *
 289  *      Returns pointer to a frame buffer colormap structure.
 290  *
 291  */
 292
 293 const struct fb_cmap *fb_default_cmap(int len)
 294 {
 295     if (len <= 2)
 296         return &default_2_colors;
 297     if (len <= 4)
 298         return &default_4_colors;
 299     if (len <= 8)
 300         return &default_8_colors;
 301     return &default_16_colors;
 302 }
 303
 304
 305 /**
 306  *      fb_invert_cmaps - invert all defaults colormaps
 307  *
 308  *      Invert all default colormaps.
 309  *
 310  */
 311
 312 void fb_invert_cmaps(void)
 313 {
 314     u_int i;
 315
 316     for (i = 0; i < ARRAY_SIZE(red2); i++) {
 317         red2[i] = ~red2[i];
 318         green2[i] = ~green2[i];
 319         blue2[i] = ~blue2[i];
 320     }
 321     for (i = 0; i < ARRAY_SIZE(red4); i++) {
 322         red4[i] = ~red4[i];
 323         green4[i] = ~green4[i];
 324         blue4[i] = ~blue4[i];
 325     }
 326     for (i = 0; i < ARRAY_SIZE(red8); i++) {
 327         red8[i] = ~red8[i];
 328         green8[i] = ~green8[i];
 329         blue8[i] = ~blue8[i];
 330     }
 331     for (i = 0; i < ARRAY_SIZE(red16); i++) {
 332         red16[i] = ~red16[i];
 333         green16[i] = ~green16[i];
 334         blue16[i] = ~blue16[i];
 335     }
 336 }
 337
 338
 339     /*
 340      *  Visible symbols for modules
 341      */
 342
 343 EXPORT_SYMBOL(fb_alloc_cmap);
 344 EXPORT_SYMBOL(fb_dealloc_cmap);
 345 EXPORT_SYMBOL(fb_copy_cmap);
 346 EXPORT_SYMBOL(fb_set_cmap);
 347 EXPORT_SYMBOL(fb_default_cmap);
 348 EXPORT_SYMBOL(fb_invert_cmaps);