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
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 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
fb_alloc_cmap(struct fb_cmap * cmap,int len,int transp)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
fb_dealloc_cmap(struct fb_cmap * cmap)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
fb_copy_cmap(const struct fb_cmap * from,struct fb_cmap * to)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
fb_cmap_to_user(const struct fb_cmap * from,struct fb_cmap_user * to)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
fb_set_cmap(struct fb_cmap * cmap,struct fb_info * info)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
fb_set_user_cmap(struct fb_cmap_user * cmap,struct fb_info * info)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
fb_default_cmap(int len)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
fb_invert_cmaps(void)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);
365
