drivers/video/fbdev/core/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  *      @flags: flags for kmalloc memory allocation
  84  *
  85  *      Allocates memory for a colormap @cmap.  @len is the
  86  *      number of entries in the palette.
  87  *
  88  *      Returns negative errno on error, or zero on success.
  89  *
  90  */
  91
  92 int fb_alloc_cmap_gfp(struct fb_cmap *cmap, int len, int transp, gfp_t flags)
  93 {
  94         int size = len * sizeof(u16);
  95         int ret = -ENOMEM;
  96
  97         if (cmap->len != len) {
  98                 fb_dealloc_cmap(cmap);
  99                 if (!len)
 100                         return 0;
 101
 102                 cmap->red = kmalloc(size, flags);
 103                 if (!cmap->red)
 104                         goto fail;
 105                 cmap->green = kmalloc(size, flags);
 106                 if (!cmap->green)
 107                         goto fail;
 108                 cmap->blue = kmalloc(size, flags);
 109                 if (!cmap->blue)
 110                         goto fail;
 111                 if (transp) {
 112                         cmap->transp = kmalloc(size, flags);
 113                         if (!cmap->transp)
 114                                 goto fail;
 115                 } else {
 116                         cmap->transp = NULL;
 117                 }
 118         }
 119         cmap->start = 0;
 120         cmap->len = len;
 121         ret = fb_copy_cmap(fb_default_cmap(len), cmap);
 122         if (ret)
 123                 goto fail;
 124         return 0;
 125
 126 fail:
 127         fb_dealloc_cmap(cmap);
 128         return ret;
 129 }
 130
 131 int fb_alloc_cmap(struct fb_cmap *cmap, int len, int transp)
 132 {
 133         return fb_alloc_cmap_gfp(cmap, len, transp, GFP_ATOMIC);
 134 }
 135
 136 /**
 137  *      fb_dealloc_cmap - deallocate a colormap
 138  *      @cmap: frame buffer colormap structure
 139  *
 140  *      Deallocates a colormap that was previously allocated with
 141  *      fb_alloc_cmap().
 142  *
 143  */
 144
 145 void fb_dealloc_cmap(struct fb_cmap *cmap)
 146 {
 147         kfree(cmap->red);
 148         kfree(cmap->green);
 149         kfree(cmap->blue);
 150         kfree(cmap->transp);
 151
 152         cmap->red = cmap->green = cmap->blue = cmap->transp = NULL;
 153         cmap->len = 0;
 154 }
 155
 156 /**
 157  *      fb_copy_cmap - copy a colormap
 158  *      @from: frame buffer colormap structure
 159  *      @to: frame buffer colormap structure
 160  *
 161  *      Copy contents of colormap from @from to @to.
 162  */
 163
 164 int fb_copy_cmap(const struct fb_cmap *from, struct fb_cmap *to)
 165 {
 166         unsigned int tooff = 0, fromoff = 0;
 167         size_t size;
 168
 169         if (to->start > from->start)
 170                 fromoff = to->start - from->start;
 171         else
 172                 tooff = from->start - to->start;
 173         if (fromoff >= from->len || tooff >= to->len)
 174                 return -EINVAL;
 175
 176         size = min_t(size_t, to->len - tooff, from->len - fromoff);
 177         if (size == 0)
 178                 return -EINVAL;
 179         size *= sizeof(u16);
 180
 181         memcpy(to->red+tooff, from->red+fromoff, size);
 182         memcpy(to->green+tooff, from->green+fromoff, size);
 183         memcpy(to->blue+tooff, from->blue+fromoff, size);
 184         if (from->transp && to->transp)
 185                 memcpy(to->transp+tooff, from->transp+fromoff, size);
 186         return 0;
 187 }
 188
 189 int fb_cmap_to_user(const struct fb_cmap *from, struct fb_cmap_user *to)
 190 {
 191         unsigned int tooff = 0, fromoff = 0;
 192         size_t size;
 193
 194         if (to->start > from->start)
 195                 fromoff = to->start - from->start;
 196         else
 197                 tooff = from->start - to->start;
 198         if (fromoff >= from->len || tooff >= to->len)
 199                 return -EINVAL;
 200
 201         size = min_t(size_t, to->len - tooff, from->len - fromoff);
 202         if (size == 0)
 203                 return -EINVAL;
 204         size *= sizeof(u16);
 205
 206         if (copy_to_user(to->red+tooff, from->red+fromoff, size))
 207                 return -EFAULT;
 208         if (copy_to_user(to->green+tooff, from->green+fromoff, size))
 209                 return -EFAULT;
 210         if (copy_to_user(to->blue+tooff, from->blue+fromoff, size))
 211                 return -EFAULT;
 212         if (from->transp && to->transp)
 213                 if (copy_to_user(to->transp+tooff, from->transp+fromoff, size))
 214                         return -EFAULT;
 215         return 0;
 216 }
 217
 218 /**
 219  *      fb_set_cmap - set the colormap
 220  *      @cmap: frame buffer colormap structure
 221  *      @info: frame buffer info structure
 222  *
 223  *      Sets the colormap @cmap for a screen of device @info.
 224  *
 225  *      Returns negative errno on error, or zero on success.
 226  *
 227  */
 228
 229 int fb_set_cmap(struct fb_cmap *cmap, struct fb_info *info)
 230 {
 231         int i, start, rc = 0;
 232         u16 *red, *green, *blue, *transp;
 233         u_int hred, hgreen, hblue, htransp = 0xffff;
 234
 235         red = cmap->red;
 236         green = cmap->green;
 237         blue = cmap->blue;
 238         transp = cmap->transp;
 239         start = cmap->start;
 240
 241         if (start < 0 || (!info->fbops->fb_setcolreg &&
 242                           !info->fbops->fb_setcmap))
 243                 return -EINVAL;
 244         if (info->fbops->fb_setcmap) {
 245                 rc = info->fbops->fb_setcmap(cmap, info);
 246         } else {
 247                 for (i = 0; i < cmap->len; i++) {
 248                         hred = *red++;
 249                         hgreen = *green++;
 250                         hblue = *blue++;
 251                         if (transp)
 252                                 htransp = *transp++;
 253                         if (info->fbops->fb_setcolreg(start++,
 254                                                       hred, hgreen, hblue,
 255                                                       htransp, info))
 256                                 break;
 257                 }
 258         }
 259         if (rc == 0)
 260                 fb_copy_cmap(cmap, &info->cmap);
 261
 262         return rc;
 263 }
 264
 265 int fb_set_user_cmap(struct fb_cmap_user *cmap, struct fb_info *info)
 266 {
 267         int rc, size = cmap->len * sizeof(u16);
 268         struct fb_cmap umap;
 269
 270         if (size < 0 || size < cmap->len)
 271                 return -E2BIG;
 272
 273         memset(&umap, 0, sizeof(struct fb_cmap));
 274         rc = fb_alloc_cmap_gfp(&umap, cmap->len, cmap->transp != NULL,
 275                                 GFP_KERNEL);
 276         if (rc)
 277                 return rc;
 278         if (copy_from_user(umap.red, cmap->red, size) ||
 279             copy_from_user(umap.green, cmap->green, size) ||
 280             copy_from_user(umap.blue, cmap->blue, size) ||
 281             (cmap->transp && copy_from_user(umap.transp, cmap->transp, size))) {
 282                 rc = -EFAULT;
 283                 goto out;
 284         }
 285         umap.start = cmap->start;
 286         if (!lock_fb_info(info)) {
 287                 rc = -ENODEV;
 288                 goto out;
 289         }
 290
 291         rc = fb_set_cmap(&umap, info);
 292         unlock_fb_info(info);
 293 out:
 294         fb_dealloc_cmap(&umap);
 295         return rc;
 296 }
 297
 298 /**
 299  *      fb_default_cmap - get default colormap
 300  *      @len: size of palette for a depth
 301  *
 302  *      Gets the default colormap for a specific screen depth.  @len
 303  *      is the size of the palette for a particular screen depth.
 304  *
 305  *      Returns pointer to a frame buffer colormap structure.
 306  *
 307  */
 308
 309 const struct fb_cmap *fb_default_cmap(int len)
 310 {
 311     if (len <= 2)
 312         return &default_2_colors;
 313     if (len <= 4)
 314         return &default_4_colors;
 315     if (len <= 8)
 316         return &default_8_colors;
 317     return &default_16_colors;
 318 }
 319
 320
 321 /**
 322  *      fb_invert_cmaps - invert all defaults colormaps
 323  *
 324  *      Invert all default colormaps.
 325  *
 326  */
 327
 328 void fb_invert_cmaps(void)
 329 {
 330     u_int i;
 331
 332     for (i = 0; i < ARRAY_SIZE(red2); i++) {
 333         red2[i] = ~red2[i];
 334         green2[i] = ~green2[i];
 335         blue2[i] = ~blue2[i];
 336     }
 337     for (i = 0; i < ARRAY_SIZE(red4); i++) {
 338         red4[i] = ~red4[i];
 339         green4[i] = ~green4[i];
 340         blue4[i] = ~blue4[i];
 341     }
 342     for (i = 0; i < ARRAY_SIZE(red8); i++) {
 343         red8[i] = ~red8[i];
 344         green8[i] = ~green8[i];
 345         blue8[i] = ~blue8[i];
 346     }
 347     for (i = 0; i < ARRAY_SIZE(red16); i++) {
 348         red16[i] = ~red16[i];
 349         green16[i] = ~green16[i];
 350         blue16[i] = ~blue16[i];
 351     }
 352 }
 353
 354
 355     /*
 356      *  Visible symbols for modules
 357      */
 358
 359 EXPORT_SYMBOL(fb_alloc_cmap);
 360 EXPORT_SYMBOL(fb_dealloc_cmap);
 361 EXPORT_SYMBOL(fb_copy_cmap);
 362 EXPORT_SYMBOL(fb_set_cmap);
 363 EXPORT_SYMBOL(fb_default_cmap);
 364 EXPORT_SYMBOL(fb_invert_cmaps);