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
289	rc = fb_set_cmap(&umap, info);
290	unlock_fb_info(info);
291out:
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
307const 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
326void 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
357EXPORT_SYMBOL(fb_alloc_cmap);
358EXPORT_SYMBOL(fb_dealloc_cmap);
359EXPORT_SYMBOL(fb_copy_cmap);
360EXPORT_SYMBOL(fb_set_cmap);
361EXPORT_SYMBOL(fb_default_cmap);
362EXPORT_SYMBOL(fb_invert_cmaps);
363