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
19#include <asm/uaccess.h>
20
21static u16 red2[] __read_mostly = {
22    0x0000, 0xaaaa
23};
24static u16 green2[] __read_mostly = {
25    0x0000, 0xaaaa
26};
27static u16 blue2[] __read_mostly = {
28    0x0000, 0xaaaa
29};
30
31static u16 red4[] __read_mostly = {
32    0x0000, 0xaaaa, 0x5555, 0xffff
33};
34static u16 green4[] __read_mostly = {
35    0x0000, 0xaaaa, 0x5555, 0xffff
36};
37static u16 blue4[] __read_mostly = {
38    0x0000, 0xaaaa, 0x5555, 0xffff
39};
40
41static u16 red8[] __read_mostly = {
42    0x0000, 0x0000, 0x0000, 0x0000, 0xaaaa, 0xaaaa, 0xaaaa, 0xaaaa
43};
44static u16 green8[] __read_mostly = {
45    0x0000, 0x0000, 0xaaaa, 0xaaaa, 0x0000, 0x0000, 0x5555, 0xaaaa
46};
47static u16 blue8[] __read_mostly = {
48    0x0000, 0xaaaa, 0x0000, 0xaaaa, 0x0000, 0xaaaa, 0x0000, 0xaaaa
49};
50
51static u16 red16[] __read_mostly = {
52    0x0000, 0x0000, 0x0000, 0x0000, 0xaaaa, 0xaaaa, 0xaaaa, 0xaaaa,
53    0x5555, 0x5555, 0x5555, 0x5555, 0xffff, 0xffff, 0xffff, 0xffff
54};
55static u16 green16[] __read_mostly = {
56    0x0000, 0x0000, 0xaaaa, 0xaaaa, 0x0000, 0x0000, 0x5555, 0xaaaa,
57    0x5555, 0x5555, 0xffff, 0xffff, 0x5555, 0x5555, 0xffff, 0xffff
58};
59static u16 blue16[] __read_mostly = {
60    0x0000, 0xaaaa, 0x0000, 0xaaaa, 0x0000, 0xaaaa, 0x0000, 0xaaaa,
61    0x5555, 0xffff, 0x5555, 0xffff, 0x5555, 0xffff, 0x5555, 0xffff
62};
63
64static const struct fb_cmap default_2_colors = {
65    .len=2, .red=red2, .green=green2, .blue=blue2
66};
67static const struct fb_cmap default_8_colors = {
68    .len=8, .red=red8, .green=green8, .blue=blue8
69};
70static const struct fb_cmap default_4_colors = {
71    .len=4, .red=red4, .green=green4, .blue=blue4
72};
73static const struct fb_cmap default_16_colors = {
74    .len=16, .red=red16, .green=green16, .blue=blue16
75};
76
77
78
79/**
80 *	fb_alloc_cmap - allocate a colormap
81 *	@cmap: frame buffer colormap structure
82 *	@len: length of @cmap
83 *	@transp: boolean, 1 if there is transparency, 0 otherwise
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(struct fb_cmap *cmap, int len, int transp)
93{
94    int size = len*sizeof(u16);
95
96    if (cmap->len != len) {
97	fb_dealloc_cmap(cmap);
98	if (!len)
99	    return 0;
100	if (!(cmap->red = kmalloc(size, GFP_ATOMIC)))
101	    goto fail;
102	if (!(cmap->green = kmalloc(size, GFP_ATOMIC)))
103	    goto fail;
104	if (!(cmap->blue = kmalloc(size, GFP_ATOMIC)))
105	    goto fail;
106	if (transp) {
107	    if (!(cmap->transp = kmalloc(size, GFP_ATOMIC)))
108		goto fail;
109	} else
110	    cmap->transp = NULL;
111    }
112    cmap->start = 0;
113    cmap->len = len;
114    fb_copy_cmap(fb_default_cmap(len), cmap);
115    return 0;
116
117fail:
118    fb_dealloc_cmap(cmap);
119    return -ENOMEM;
120}
121
122/**
123 *      fb_dealloc_cmap - deallocate a colormap
124 *      @cmap: frame buffer colormap structure
125 *
126 *      Deallocates a colormap that was previously allocated with
127 *      fb_alloc_cmap().
128 *
129 */
130
131void fb_dealloc_cmap(struct fb_cmap *cmap)
132{
133	kfree(cmap->red);
134	kfree(cmap->green);
135	kfree(cmap->blue);
136	kfree(cmap->transp);
137
138	cmap->red = cmap->green = cmap->blue = cmap->transp = NULL;
139	cmap->len = 0;
140}
141
142/**
143 *	fb_copy_cmap - copy a colormap
144 *	@from: frame buffer colormap structure
145 *	@to: frame buffer colormap structure
146 *
147 *	Copy contents of colormap from @from to @to.
148 */
149
150int fb_copy_cmap(const struct fb_cmap *from, struct fb_cmap *to)
151{
152	int tooff = 0, fromoff = 0;
153	int size;
154
155	if (to->start > from->start)
156		fromoff = to->start - from->start;
157	else
158		tooff = from->start - to->start;
159	size = to->len - tooff;
160	if (size > (int) (from->len - fromoff))
161		size = from->len - fromoff;
162	if (size <= 0)
163		return -EINVAL;
164	size *= sizeof(u16);
165
166	memcpy(to->red+tooff, from->red+fromoff, size);
167	memcpy(to->green+tooff, from->green+fromoff, size);
168	memcpy(to->blue+tooff, from->blue+fromoff, size);
169	if (from->transp && to->transp)
170		memcpy(to->transp+tooff, from->transp+fromoff, size);
171	return 0;
172}
173
174int fb_cmap_to_user(const struct fb_cmap *from, struct fb_cmap_user *to)
175{
176	int tooff = 0, fromoff = 0;
177	int size;
178
179	if (to->start > from->start)
180		fromoff = to->start - from->start;
181	else
182		tooff = from->start - to->start;
183	size = to->len - tooff;
184	if (size > (int) (from->len - fromoff))
185		size = from->len - fromoff;
186	if (size <= 0)
187		return -EINVAL;
188	size *= sizeof(u16);
189
190	if (copy_to_user(to->red+tooff, from->red+fromoff, size))
191		return -EFAULT;
192	if (copy_to_user(to->green+tooff, from->green+fromoff, size))
193		return -EFAULT;
194	if (copy_to_user(to->blue+tooff, from->blue+fromoff, size))
195		return -EFAULT;
196	if (from->transp && to->transp)
197		if (copy_to_user(to->transp+tooff, from->transp+fromoff, size))
198			return -EFAULT;
199	return 0;
200}
201
202/**
203 *	fb_set_cmap - set the colormap
204 *	@cmap: frame buffer colormap structure
205 *	@info: frame buffer info structure
206 *
207 *	Sets the colormap @cmap for a screen of device @info.
208 *
209 *	Returns negative errno on error, or zero on success.
210 *
211 */
212
213int fb_set_cmap(struct fb_cmap *cmap, struct fb_info *info)
214{
215	int i, start, rc = 0;
216	u16 *red, *green, *blue, *transp;
217	u_int hred, hgreen, hblue, htransp = 0xffff;
218
219	red = cmap->red;
220	green = cmap->green;
221	blue = cmap->blue;
222	transp = cmap->transp;
223	start = cmap->start;
224
225	if (start < 0 || (!info->fbops->fb_setcolreg &&
226			  !info->fbops->fb_setcmap))
227		return -EINVAL;
228	if (info->fbops->fb_setcmap) {
229		rc = info->fbops->fb_setcmap(cmap, info);
230	} else {
231		for (i = 0; i < cmap->len; i++) {
232			hred = *red++;
233			hgreen = *green++;
234			hblue = *blue++;
235			if (transp)
236				htransp = *transp++;
237			if (info->fbops->fb_setcolreg(start++,
238						      hred, hgreen, hblue,
239						      htransp, info))
240				break;
241		}
242	}
243	if (rc == 0)
244		fb_copy_cmap(cmap, &info->cmap);
245
246	return rc;
247}
248
249int fb_set_user_cmap(struct fb_cmap_user *cmap, struct fb_info *info)
250{
251	int rc, size = cmap->len * sizeof(u16);
252	struct fb_cmap umap;
253
254	if (cmap->start < 0 || (!info->fbops->fb_setcolreg &&
255			        !info->fbops->fb_setcmap))
256		return -EINVAL;
257
258	memset(&umap, 0, sizeof(struct fb_cmap));
259	rc = fb_alloc_cmap(&umap, cmap->len, cmap->transp != NULL);
260	if (rc)
261		return rc;
262	if (copy_from_user(umap.red, cmap->red, size) ||
263	    copy_from_user(umap.green, cmap->green, size) ||
264	    copy_from_user(umap.blue, cmap->blue, size) ||
265	    (cmap->transp && copy_from_user(umap.transp, cmap->transp, size))) {
266		fb_dealloc_cmap(&umap);
267		return -EFAULT;
268	}
269	umap.start = cmap->start;
270	rc = fb_set_cmap(&umap, info);
271	fb_dealloc_cmap(&umap);
272	return rc;
273}
274
275/**
276 *	fb_default_cmap - get default colormap
277 *	@len: size of palette for a depth
278 *
279 *	Gets the default colormap for a specific screen depth.  @len
280 *	is the size of the palette for a particular screen depth.
281 *
282 *	Returns pointer to a frame buffer colormap structure.
283 *
284 */
285
286const struct fb_cmap *fb_default_cmap(int len)
287{
288    if (len <= 2)
289	return &default_2_colors;
290    if (len <= 4)
291	return &default_4_colors;
292    if (len <= 8)
293	return &default_8_colors;
294    return &default_16_colors;
295}
296
297
298/**
299 *	fb_invert_cmaps - invert all defaults colormaps
300 *
301 *	Invert all default colormaps.
302 *
303 */
304
305void fb_invert_cmaps(void)
306{
307    u_int i;
308
309    for (i = 0; i < ARRAY_SIZE(red2); i++) {
310	red2[i] = ~red2[i];
311	green2[i] = ~green2[i];
312	blue2[i] = ~blue2[i];
313    }
314    for (i = 0; i < ARRAY_SIZE(red4); i++) {
315	red4[i] = ~red4[i];
316	green4[i] = ~green4[i];
317	blue4[i] = ~blue4[i];
318    }
319    for (i = 0; i < ARRAY_SIZE(red8); i++) {
320	red8[i] = ~red8[i];
321	green8[i] = ~green8[i];
322	blue8[i] = ~blue8[i];
323    }
324    for (i = 0; i < ARRAY_SIZE(red16); i++) {
325	red16[i] = ~red16[i];
326	green16[i] = ~green16[i];
327	blue16[i] = ~blue16[i];
328    }
329}
330
331
332    /*
333     *  Visible symbols for modules
334     */
335
336EXPORT_SYMBOL(fb_alloc_cmap);
337EXPORT_SYMBOL(fb_dealloc_cmap);
338EXPORT_SYMBOL(fb_copy_cmap);
339EXPORT_SYMBOL(fb_set_cmap);
340EXPORT_SYMBOL(fb_default_cmap);
341EXPORT_SYMBOL(fb_invert_cmaps);
342