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