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_gfp(struct fb_cmap *cmap, int len, int transp, gfp_t flags)
  92 {
  93         int size = len * sizeof(u16);
  94         int ret = -ENOMEM;
  95
  96         if (cmap->len != len) {
  97                 fb_dealloc_cmap(cmap);
  98                 if (!len)
  99                         return 0;
 100
 101                 cmap->red = kmalloc(size, flags);
 102                 if (!cmap->red)
 103                         goto fail;
 104                 cmap->green = kmalloc(size, flags);
 105                 if (!cmap->green)
 106                         goto fail;
 107                 cmap->blue = kmalloc(size, flags);
 108                 if (!cmap->blue)
 109                         goto fail;
 110                 if (transp) {
 111                         cmap->transp = kmalloc(size, flags);
 112                         if (!cmap->transp)
 113                                 goto fail;
 114                 } else {
 115                         cmap->transp = NULL;
 116                 }
 117         }
 118         cmap->start = 0;
 119         cmap->len = len;
 120         ret = fb_copy_cmap(fb_default_cmap(len), cmap);
 121         if (ret)
 122                 goto fail;
 123         return 0;
 124
 125 fail:
 126         fb_dealloc_cmap(cmap);
 127         return ret;
 128 }
 129
 130 int fb_alloc_cmap(struct fb_cmap *cmap, int len, int transp)
 131 {
 132         return fb_alloc_cmap_gfp(cmap, len, transp, GFP_ATOMIC);
 133 }
 134
 135 /**
 136  *      fb_dealloc_cmap - deallocate a colormap
 137  *      @cmap: frame buffer colormap structure
 138  *
 139  *      Deallocates a colormap that was previously allocated with
 140  *      fb_alloc_cmap().
 141  *
 142  */
 143
 144 void fb_dealloc_cmap(struct fb_cmap *cmap)
 145 {
 146         kfree(cmap->red);
 147         kfree(cmap->green);
 148         kfree(cmap->blue);
 149         kfree(cmap->transp);
 150
 151         cmap->red = cmap->green = cmap->blue = cmap->transp = NULL;
 152         cmap->len = 0;
 153 }
 154
 155 /**
 156  *      fb_copy_cmap - copy a colormap
 157  *      @from: frame buffer colormap structure
 158  *      @to: frame buffer colormap structure
 159  *
 160  *      Copy contents of colormap from @from to @to.
 161  */
 162
 163 int fb_copy_cmap(const struct fb_cmap *from, struct fb_cmap *to)
 164 {
 165         int tooff = 0, fromoff = 0;
 166         int size;
 167
 168         if (to->start > from->start)
 169                 fromoff = to->start - from->start;
 170         else
 171                 tooff = from->start - to->start;
 172         size = to->len - tooff;
 173         if (size > (int) (from->len - fromoff))
 174                 size = from->len - fromoff;
 175         if (size <= 0)
 176                 return -EINVAL;
 177         size *= sizeof(u16);
 178
 179         memcpy(to->red+tooff, from->red+fromoff, size);
 180         memcpy(to->green+tooff, from->green+fromoff, size);
 181         memcpy(to->blue+tooff, from->blue+fromoff, size);
 182         if (from->transp && to->transp)
 183                 memcpy(to->transp+tooff, from->transp+fromoff, size);
 184         return 0;
 185 }
 186
 187 int fb_cmap_to_user(const struct fb_cmap *from, struct fb_cmap_user *to)
 188 {
 189         int tooff = 0, fromoff = 0;
 190         int size;
 191
 192         if (to->start > from->start)
 193                 fromoff = to->start - from->start;
 194         else
 195                 tooff = from->start - to->start;
 196         size = to->len - tooff;
 197         if (size > (int) (from->len - fromoff))
 198                 size = from->len - fromoff;
 199         if (size <= 0)
 200                 return -EINVAL;
 201         size *= sizeof(u16);
 202
 203         if (copy_to_user(to->red+tooff, from->red+fromoff, size))
 204                 return -EFAULT;
 205         if (copy_to_user(to->green+tooff, from->green+fromoff, size))
 206                 return -EFAULT;
 207         if (copy_to_user(to->blue+tooff, from->blue+fromoff, size))
 208                 return -EFAULT;
 209         if (from->transp && to->transp)
 210                 if (copy_to_user(to->transp+tooff, from->transp+fromoff, size))
 211                         return -EFAULT;
 212         return 0;
 213 }
 214
 215 /**
 216  *      fb_set_cmap - set the colormap
 217  *      @cmap: frame buffer colormap structure
 218  *      @info: frame buffer info structure
 219  *
 220  *      Sets the colormap @cmap for a screen of device @info.
 221  *
 222  *      Returns negative errno on error, or zero on success.
 223  *
 224  */
 225
 226 int fb_set_cmap(struct fb_cmap *cmap, struct fb_info *info)
 227 {
 228         int i, start, rc = 0;
 229         u16 *red, *green, *blue, *transp;
 230         u_int hred, hgreen, hblue, htransp = 0xffff;
 231
 232         red = cmap->red;
 233         green = cmap->green;
 234         blue = cmap->blue;
 235         transp = cmap->transp;
 236         start = cmap->start;
 237
 238         if (start < 0 || (!info->fbops->fb_setcolreg &&
 239                           !info->fbops->fb_setcmap))
 240                 return -EINVAL;
 241         if (info->fbops->fb_setcmap) {
 242                 rc = info->fbops->fb_setcmap(cmap, info);
 243         } else {
 244                 for (i = 0; i < cmap->len; i++) {
 245                         hred = *red++;
 246                         hgreen = *green++;
 247                         hblue = *blue++;
 248                         if (transp)
 249                                 htransp = *transp++;
 250                         if (info->fbops->fb_setcolreg(start++,
 251                                                       hred, hgreen, hblue,
 252                                                       htransp, info))
 253                                 break;
 254                 }
 255         }
 256         if (rc == 0)
 257                 fb_copy_cmap(cmap, &info->cmap);
 258
 259         return rc;
 260 }
 261
 262 int fb_set_user_cmap(struct fb_cmap_user *cmap, struct fb_info *info)
 263 {
 264         int rc, size = cmap->len * sizeof(u16);
 265         struct fb_cmap umap;
 266
 267         if (size < 0 || size < cmap->len)
 268                 return -E2BIG;
 269
 270         memset(&umap, 0, sizeof(struct fb_cmap));
 271         rc = fb_alloc_cmap_gfp(&umap, cmap->len, cmap->transp != NULL,
 272                                 GFP_KERNEL);
 273         if (rc)
 274                 return rc;
 275         if (copy_from_user(umap.red, cmap->red, size) ||
 276             copy_from_user(umap.green, cmap->green, size) ||
 277             copy_from_user(umap.blue, cmap->blue, size) ||
 278             (cmap->transp && copy_from_user(umap.transp, cmap->transp, size))) {
 279                 rc = -EFAULT;
 280                 goto out;
 281         }
 282         umap.start = cmap->start;
 283         if (!lock_fb_info(info)) {
 284                 rc = -ENODEV;
 285                 goto out;
 286         }
 287         if (cmap->start < 0 || (!info->fbops->fb_setcolreg &&
 288                                 !info->fbops->fb_setcmap)) {
 289                 rc = -EINVAL;
 290                 goto out1;
 291         }
 292         rc = fb_set_cmap(&umap, info);
 293 out1:
 294         unlock_fb_info(info);
 295 out:
 296         fb_dealloc_cmap(&umap);
 297         return rc;
 298 }
 299
 300 /**
 301  *      fb_default_cmap - get default colormap
 302  *      @len: size of palette for a depth
 303  *
 304  *      Gets the default colormap for a specific screen depth.  @len
 305  *      is the size of the palette for a particular screen depth.
 306  *
 307  *      Returns pointer to a frame buffer colormap structure.
 308  *
 309  */
 310
 311 const struct fb_cmap *fb_default_cmap(int len)
 312 {
 313     if (len <= 2)
 314         return &default_2_colors;
 315     if (len <= 4)
 316         return &default_4_colors;
 317     if (len <= 8)
 318         return &default_8_colors;
 319     return &default_16_colors;
 320 }
 321
 322
 323 /**
 324  *      fb_invert_cmaps - invert all defaults colormaps
 325  *
 326  *      Invert all default colormaps.
 327  *
 328  */
 329
 330 void fb_invert_cmaps(void)
 331 {
 332     u_int i;
 333
 334     for (i = 0; i < ARRAY_SIZE(red2); i++) {
 335         red2[i] = ~red2[i];
 336         green2[i] = ~green2[i];
 337         blue2[i] = ~blue2[i];
 338     }
 339     for (i = 0; i < ARRAY_SIZE(red4); i++) {
 340         red4[i] = ~red4[i];
 341         green4[i] = ~green4[i];
 342         blue4[i] = ~blue4[i];
 343     }
 344     for (i = 0; i < ARRAY_SIZE(red8); i++) {
 345         red8[i] = ~red8[i];
 346         green8[i] = ~green8[i];
 347         blue8[i] = ~blue8[i];
 348     }
 349     for (i = 0; i < ARRAY_SIZE(red16); i++) {
 350         red16[i] = ~red16[i];
 351         green16[i] = ~green16[i];
 352         blue16[i] = ~blue16[i];
 353     }
 354 }
 355
 356
 357     /*
 358      *  Visible symbols for modules
 359      */
 360
 361 EXPORT_SYMBOL(fb_alloc_cmap);
 362 EXPORT_SYMBOL(fb_dealloc_cmap);
 363 EXPORT_SYMBOL(fb_copy_cmap);
 364 EXPORT_SYMBOL(fb_set_cmap);
 365 EXPORT_SYMBOL(fb_default_cmap);
 366 EXPORT_SYMBOL(fb_invert_cmaps);