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/tty.h>
17#include <linux/fb.h>
18#include <linux/slab.h>
19
20#include <asm/uaccess.h>
21
22static u16 red2[] = {
23    0x0000, 0xaaaa
24};
25static u16 green2[] = {
26    0x0000, 0xaaaa
27};
28static u16 blue2[] = {
29    0x0000, 0xaaaa
30};
31
32static u16 red4[] = {
33    0x0000, 0xaaaa, 0x5555, 0xffff
34};
35static u16 green4[] = {
36    0x0000, 0xaaaa, 0x5555, 0xffff
37};
38static u16 blue4[] = {
39    0x0000, 0xaaaa, 0x5555, 0xffff
40};
41
42static u16 red8[] = {
43    0x0000, 0x0000, 0x0000, 0x0000, 0xaaaa, 0xaaaa, 0xaaaa, 0xaaaa
44};
45static u16 green8[] = {
46    0x0000, 0x0000, 0xaaaa, 0xaaaa, 0x0000, 0x0000, 0x5555, 0xaaaa
47};
48static u16 blue8[] = {
49    0x0000, 0xaaaa, 0x0000, 0xaaaa, 0x0000, 0xaaaa, 0x0000, 0xaaaa
50};
51
52static u16 red16[] = {
53    0x0000, 0x0000, 0x0000, 0x0000, 0xaaaa, 0xaaaa, 0xaaaa, 0xaaaa,
54    0x5555, 0x5555, 0x5555, 0x5555, 0xffff, 0xffff, 0xffff, 0xffff
55};
56static u16 green16[] = {
57    0x0000, 0x0000, 0xaaaa, 0xaaaa, 0x0000, 0x0000, 0x5555, 0xaaaa,
58    0x5555, 0x5555, 0xffff, 0xffff, 0x5555, 0x5555, 0xffff, 0xffff
59};
60static u16 blue16[] = {
61    0x0000, 0xaaaa, 0x0000, 0xaaaa, 0x0000, 0xaaaa, 0x0000, 0xaaaa,
62    0x5555, 0xffff, 0x5555, 0xffff, 0x5555, 0xffff, 0x5555, 0xffff
63};
64
65static struct fb_cmap default_2_colors = {
66    0, 2, red2, green2, blue2, NULL
67};
68static struct fb_cmap default_8_colors = {
69    0, 8, red8, green8, blue8, NULL
70};
71static struct fb_cmap default_4_colors = {
72    0, 4, red4, green4, blue4, NULL
73};
74static struct fb_cmap default_16_colors = {
75    0, 16, red16, green16, blue16, NULL
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 -1 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	if (cmap->red)
98	    kfree(cmap->red);
99	if (cmap->green)
100	    kfree(cmap->green);
101	if (cmap->blue)
102	    kfree(cmap->blue);
103	if (cmap->transp)
104	    kfree(cmap->transp);
105	cmap->red = cmap->green = cmap->blue = cmap->transp = NULL;
106	cmap->len = 0;
107	if (!len)
108	    return 0;
109	if (!(cmap->red = kmalloc(size, GFP_ATOMIC)))
110	    return -1;
111	if (!(cmap->green = kmalloc(size, GFP_ATOMIC)))
112	    return -1;
113	if (!(cmap->blue = kmalloc(size, GFP_ATOMIC)))
114	    return -1;
115	if (transp) {
116	    if (!(cmap->transp = kmalloc(size, GFP_ATOMIC)))
117		return -1;
118	} else
119	    cmap->transp = NULL;
120    }
121    cmap->start = 0;
122    cmap->len = len;
123    fb_copy_cmap(fb_default_cmap(len), cmap, 0);
124    return 0;
125}
126
127
128/**
129 *	fb_copy_cmap - copy a colormap
130 *	@from: frame buffer colormap structure
131 *	@to: frame buffer colormap structure
132 *	@fsfromto: determine copy method
133 *
134 *	Copy contents of colormap from @from to @to.
135 *
136 *	@fsfromto accepts the following integer parameters:
137 *	0: memcpy function
138 *	1: copy_from_user() function to copy from userspace
139 *	2: copy_to_user() function to copy to userspace
140 *
141 */
142
143void fb_copy_cmap(struct fb_cmap *from, struct fb_cmap *to, int fsfromto)
144{
145    int size;
146    int tooff = 0, fromoff = 0;
147
148    if (to->start > from->start)
149	fromoff = to->start-from->start;
150    else
151	tooff = from->start-to->start;
152    size = to->len-tooff;
153    if (size > from->len-fromoff)
154	size = from->len-fromoff;
155    if (size < 0)
156	return;
157    size *= sizeof(u16);
158
159    switch (fsfromto) {
160    case 0:
161	memcpy(to->red+tooff, from->red+fromoff, size);
162	memcpy(to->green+tooff, from->green+fromoff, size);
163	memcpy(to->blue+tooff, from->blue+fromoff, size);
164	if (from->transp && to->transp)
165	    memcpy(to->transp+tooff, from->transp+fromoff, size);
166        break;
167    case 1:
168	copy_from_user(to->red+tooff, from->red+fromoff, size);
169	copy_from_user(to->green+tooff, from->green+fromoff, size);
170	copy_from_user(to->blue+tooff, from->blue+fromoff, size);
171	if (from->transp && to->transp)
172            copy_from_user(to->transp+tooff, from->transp+fromoff, size);
173	break;
174    case 2:
175	copy_to_user(to->red+tooff, from->red+fromoff, size);
176	copy_to_user(to->green+tooff, from->green+fromoff, size);
177	copy_to_user(to->blue+tooff, from->blue+fromoff, size);
178	if (from->transp && to->transp)
179	    copy_to_user(to->transp+tooff, from->transp+fromoff, size);
180	break;
181    }
182}
183
184
185/**
186 *	fb_get_cmap - get a colormap
187 *	@cmap: frame buffer colormap
188 *	@kspc: boolean, 0 copy local, 1 put_user() function
189 *	@getcolreg: pointer to a function to get a color register
190 *	@info: frame buffer info structure
191 *
192 *	Get a colormap @cmap for a screen of device @info.
193 *
194 *	Returns negative errno on error, or zero on success.
195 *
196 */
197
198int fb_get_cmap(struct fb_cmap *cmap, int kspc,
199    	    	int (*getcolreg)(u_int, u_int *, u_int *, u_int *, u_int *,
200				 struct fb_info *),
201		struct fb_info *info)
202{
203    int i, start;
204    u16 *red, *green, *blue, *transp;
205    u_int hred, hgreen, hblue, htransp;
206
207    red = cmap->red;
208    green = cmap->green;
209    blue = cmap->blue;
210    transp = cmap->transp;
211    start = cmap->start;
212    if (start < 0)
213	return -EINVAL;
214    for (i = 0; i < cmap->len; i++) {
215	if (getcolreg(start++, &hred, &hgreen, &hblue, &htransp, info))
216	    return 0;
217	if (kspc) {
218	    *red = hred;
219	    *green = hgreen;
220	    *blue = hblue;
221	    if (transp)
222		*transp = htransp;
223	} else {
224	    put_user(hred, red);
225	    put_user(hgreen, green);
226	    put_user(hblue, blue);
227	    if (transp)
228		put_user(htransp, transp);
229	}
230	red++;
231	green++;
232	blue++;
233	if (transp)
234	    transp++;
235    }
236    return 0;
237}
238
239
240/**
241 *	fb_set_cmap - set the colormap
242 *	@cmap: frame buffer colormap structure
243 *	@kspc: boolean, 0 copy local, 1 get_user() function
244 *	@info: frame buffer info structure
245 *
246 *	Sets the colormap @cmap for a screen of device @info.
247 *
248 *	Returns negative errno on error, or zero on success.
249 *
250 */
251
252int fb_set_cmap(struct fb_cmap *cmap, int kspc,
253    	    	int (*setcolreg)(u_int, u_int, u_int, u_int, u_int,
254				 struct fb_info *),
255		struct fb_info *info)
256{
257    int i, start;
258    u16 *red, *green, *blue, *transp;
259    u_int hred, hgreen, hblue, htransp;
260
261    red = cmap->red;
262    green = cmap->green;
263    blue = cmap->blue;
264    transp = cmap->transp;
265    start = cmap->start;
266
267    if (start < 0)
268	return -EINVAL;
269    for (i = 0; i < cmap->len; i++) {
270	if (kspc) {
271	    hred = *red;
272	    hgreen = *green;
273	    hblue = *blue;
274	    htransp = transp ? *transp : 0;
275	} else {
276	    get_user(hred, red);
277	    get_user(hgreen, green);
278	    get_user(hblue, blue);
279	    if (transp)
280		get_user(htransp, transp);
281	    else
282		htransp = 0;
283	}
284	red++;
285	green++;
286	blue++;
287	if (transp)
288	    transp++;
289	if (setcolreg(start++, hred, hgreen, hblue, htransp, info))
290	    return 0;
291    }
292    return 0;
293}
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
307struct 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 < 2; i++) {
331	red2[i] = ~red2[i];
332	green2[i] = ~green2[i];
333	blue2[i] = ~blue2[i];
334    }
335    for (i = 0; i < 4; i++) {
336	red4[i] = ~red4[i];
337	green4[i] = ~green4[i];
338	blue4[i] = ~blue4[i];
339    }
340    for (i = 0; i < 8; i++) {
341	red8[i] = ~red8[i];
342	green8[i] = ~green8[i];
343	blue8[i] = ~blue8[i];
344    }
345    for (i = 0; i < 16; 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_copy_cmap);
359EXPORT_SYMBOL(fb_get_cmap);
360EXPORT_SYMBOL(fb_set_cmap);
361EXPORT_SYMBOL(fb_default_cmap);
362EXPORT_SYMBOL(fb_invert_cmaps);
363