linux/drivers/video/fbcmap.c
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   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
  20static u16 red2[] __read_mostly = {
  21    0x0000, 0xaaaa
  22};
  23static u16 green2[] __read_mostly = {
  24    0x0000, 0xaaaa
  25};
  26static u16 blue2[] __read_mostly = {
  27    0x0000, 0xaaaa
  28};
  29
  30static u16 red4[] __read_mostly = {
  31    0x0000, 0xaaaa, 0x5555, 0xffff
  32};
  33static u16 green4[] __read_mostly = {
  34    0x0000, 0xaaaa, 0x5555, 0xffff
  35};
  36static u16 blue4[] __read_mostly = {
  37    0x0000, 0xaaaa, 0x5555, 0xffff
  38};
  39
  40static u16 red8[] __read_mostly = {
  41    0x0000, 0x0000, 0x0000, 0x0000, 0xaaaa, 0xaaaa, 0xaaaa, 0xaaaa
  42};
  43static u16 green8[] __read_mostly = {
  44    0x0000, 0x0000, 0xaaaa, 0xaaaa, 0x0000, 0x0000, 0x5555, 0xaaaa
  45};
  46static u16 blue8[] __read_mostly = {
  47    0x0000, 0xaaaa, 0x0000, 0xaaaa, 0x0000, 0xaaaa, 0x0000, 0xaaaa
  48};
  49
  50static u16 red16[] __read_mostly = {
  51    0x0000, 0x0000, 0x0000, 0x0000, 0xaaaa, 0xaaaa, 0xaaaa, 0xaaaa,
  52    0x5555, 0x5555, 0x5555, 0x5555, 0xffff, 0xffff, 0xffff, 0xffff
  53};
  54static u16 green16[] __read_mostly = {
  55    0x0000, 0x0000, 0xaaaa, 0xaaaa, 0x0000, 0x0000, 0x5555, 0xaaaa,
  56    0x5555, 0x5555, 0xffff, 0xffff, 0x5555, 0x5555, 0xffff, 0xffff
  57};
  58static u16 blue16[] __read_mostly = {
  59    0x0000, 0xaaaa, 0x0000, 0xaaaa, 0x0000, 0xaaaa, 0x0000, 0xaaaa,
  60    0x5555, 0xffff, 0x5555, 0xffff, 0x5555, 0xffff, 0x5555, 0xffff
  61};
  62
  63static const struct fb_cmap default_2_colors = {
  64    .len=2, .red=red2, .green=green2, .blue=blue2
  65};
  66static const struct fb_cmap default_8_colors = {
  67    .len=8, .red=red8, .green=green8, .blue=blue8
  68};
  69static const struct fb_cmap default_4_colors = {
  70    .len=4, .red=red4, .green=green4, .blue=blue4
  71};
  72static 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
  92int 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
 126fail:
 127        fb_dealloc_cmap(cmap);
 128        return ret;
 129}
 130
 131int 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
 145void 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
 164int fb_copy_cmap(const struct fb_cmap *from, struct fb_cmap *to)
 165{
 166        int tooff = 0, fromoff = 0;
 167        int size;
 168
 169        if (to->start > from->start)
 170                fromoff = to->start - from->start;
 171        else
 172                tooff = from->start - to->start;
 173        size = to->len - tooff;
 174        if (size > (int) (from->len - fromoff))
 175                size = from->len - fromoff;
 176        if (size <= 0)
 177                return -EINVAL;
 178        size *= sizeof(u16);
 179
 180        memcpy(to->red+tooff, from->red+fromoff, size);
 181        memcpy(to->green+tooff, from->green+fromoff, size);
 182        memcpy(to->blue+tooff, from->blue+fromoff, size);
 183        if (from->transp && to->transp)
 184                memcpy(to->transp+tooff, from->transp+fromoff, size);
 185        return 0;
 186}
 187
 188int fb_cmap_to_user(const struct fb_cmap *from, struct fb_cmap_user *to)
 189{
 190        int tooff = 0, fromoff = 0;
 191        int size;
 192
 193        if (to->start > from->start)
 194                fromoff = to->start - from->start;
 195        else
 196                tooff = from->start - to->start;
 197        size = to->len - tooff;
 198        if (size > (int) (from->len - fromoff))
 199                size = from->len - fromoff;
 200        if (size <= 0)
 201                return -EINVAL;
 202        size *= sizeof(u16);
 203
 204        if (copy_to_user(to->red+tooff, from->red+fromoff, size))
 205                return -EFAULT;
 206        if (copy_to_user(to->green+tooff, from->green+fromoff, size))
 207                return -EFAULT;
 208        if (copy_to_user(to->blue+tooff, from->blue+fromoff, size))
 209                return -EFAULT;
 210        if (from->transp && to->transp)
 211                if (copy_to_user(to->transp+tooff, from->transp+fromoff, size))
 212                        return -EFAULT;
 213        return 0;
 214}
 215
 216/**
 217 *      fb_set_cmap - set the colormap
 218 *      @cmap: frame buffer colormap structure
 219 *      @info: frame buffer info structure
 220 *
 221 *      Sets the colormap @cmap for a screen of device @info.
 222 *
 223 *      Returns negative errno on error, or zero on success.
 224 *
 225 */
 226
 227int fb_set_cmap(struct fb_cmap *cmap, struct fb_info *info)
 228{
 229        int i, start, rc = 0;
 230        u16 *red, *green, *blue, *transp;
 231        u_int hred, hgreen, hblue, htransp = 0xffff;
 232
 233        red = cmap->red;
 234        green = cmap->green;
 235        blue = cmap->blue;
 236        transp = cmap->transp;
 237        start = cmap->start;
 238
 239        if (start < 0 || (!info->fbops->fb_setcolreg &&
 240                          !info->fbops->fb_setcmap))
 241                return -EINVAL;
 242        if (info->fbops->fb_setcmap) {
 243                rc = info->fbops->fb_setcmap(cmap, info);
 244        } else {
 245                for (i = 0; i < cmap->len; i++) {
 246                        hred = *red++;
 247                        hgreen = *green++;
 248                        hblue = *blue++;
 249                        if (transp)
 250                                htransp = *transp++;
 251                        if (info->fbops->fb_setcolreg(start++,
 252                                                      hred, hgreen, hblue,
 253                                                      htransp, info))
 254                                break;
 255                }
 256        }
 257        if (rc == 0)
 258                fb_copy_cmap(cmap, &info->cmap);
 259
 260        return rc;
 261}
 262
 263int fb_set_user_cmap(struct fb_cmap_user *cmap, struct fb_info *info)
 264{
 265        int rc, size = cmap->len * sizeof(u16);
 266        struct fb_cmap umap;
 267
 268        if (size < 0 || size < cmap->len)
 269                return -E2BIG;
 270
 271        memset(&umap, 0, sizeof(struct fb_cmap));
 272        rc = fb_alloc_cmap_gfp(&umap, cmap->len, cmap->transp != NULL,
 273                                GFP_KERNEL);
 274        if (rc)
 275                return rc;
 276        if (copy_from_user(umap.red, cmap->red, size) ||
 277            copy_from_user(umap.green, cmap->green, size) ||
 278            copy_from_user(umap.blue, cmap->blue, size) ||
 279            (cmap->transp && copy_from_user(umap.transp, cmap->transp, size))) {
 280                rc = -EFAULT;
 281                goto out;
 282        }
 283        umap.start = cmap->start;
 284        if (!lock_fb_info(info)) {
 285                rc = -ENODEV;
 286                goto out;
 287        }
 288        if (cmap->start < 0 || (!info->fbops->fb_setcolreg &&
 289                                !info->fbops->fb_setcmap)) {
 290                rc = -EINVAL;
 291                goto out1;
 292        }
 293        rc = fb_set_cmap(&umap, info);
 294out1:
 295        unlock_fb_info(info);
 296out:
 297        fb_dealloc_cmap(&umap);
 298        return rc;
 299}
 300
 301/**
 302 *      fb_default_cmap - get default colormap
 303 *      @len: size of palette for a depth
 304 *
 305 *      Gets the default colormap for a specific screen depth.  @len
 306 *      is the size of the palette for a particular screen depth.
 307 *
 308 *      Returns pointer to a frame buffer colormap structure.
 309 *
 310 */
 311
 312const struct fb_cmap *fb_default_cmap(int len)
 313{
 314    if (len <= 2)
 315        return &default_2_colors;
 316    if (len <= 4)
 317        return &default_4_colors;
 318    if (len <= 8)
 319        return &default_8_colors;
 320    return &default_16_colors;
 321}
 322
 323
 324/**
 325 *      fb_invert_cmaps - invert all defaults colormaps
 326 *
 327 *      Invert all default colormaps.
 328 *
 329 */
 330
 331void fb_invert_cmaps(void)
 332{
 333    u_int i;
 334
 335    for (i = 0; i < ARRAY_SIZE(red2); i++) {
 336        red2[i] = ~red2[i];
 337        green2[i] = ~green2[i];
 338        blue2[i] = ~blue2[i];
 339    }
 340    for (i = 0; i < ARRAY_SIZE(red4); i++) {
 341        red4[i] = ~red4[i];
 342        green4[i] = ~green4[i];
 343        blue4[i] = ~blue4[i];
 344    }
 345    for (i = 0; i < ARRAY_SIZE(red8); i++) {
 346        red8[i] = ~red8[i];
 347        green8[i] = ~green8[i];
 348        blue8[i] = ~blue8[i];
 349    }
 350    for (i = 0; i < ARRAY_SIZE(red16); i++) {
 351        red16[i] = ~red16[i];
 352        green16[i] = ~green16[i];
 353        blue16[i] = ~blue16[i];
 354    }
 355}
 356
 357
 358    /*
 359     *  Visible symbols for modules
 360     */
 361
 362EXPORT_SYMBOL(fb_alloc_cmap);
 363EXPORT_SYMBOL(fb_dealloc_cmap);
 364EXPORT_SYMBOL(fb_copy_cmap);
 365EXPORT_SYMBOL(fb_set_cmap);
 366EXPORT_SYMBOL(fb_default_cmap);
 367EXPORT_SYMBOL(fb_invert_cmaps);
 368
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