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_gfp - 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
fb_alloc_cmap_gfp(struct fb_cmap * cmap,int len,int transp,gfp_t flags)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 = kzalloc(size, flags);
105 if (!cmap->red)
106 goto fail;
107 cmap->green = kzalloc(size, flags);
108 if (!cmap->green)
109 goto fail;
110 cmap->blue = kzalloc(size, flags);
111 if (!cmap->blue)
112 goto fail;
113 if (transp) {
114 cmap->transp = kzalloc(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
fb_alloc_cmap(struct fb_cmap * cmap,int len,int transp)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
fb_dealloc_cmap(struct fb_cmap * cmap)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
fb_copy_cmap(const struct fb_cmap * from,struct fb_cmap * to)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
fb_cmap_to_user(const struct fb_cmap * from,struct fb_cmap_user * to)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
fb_set_cmap(struct fb_cmap * cmap,struct fb_info * info)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
fb_set_user_cmap(struct fb_cmap_user * cmap,struct fb_info * info)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
fb_default_cmap(int len)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
fb_invert_cmaps(void)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