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