fbcmap.c

  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/export.h>
 15#include <linux/string.h>
 16#include <linux/module.h>
 17#include <linux/fb.h>
 18#include <linux/slab.h>
 19#include <linux/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_gfp - 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 *	@flags: flags for kmalloc memory allocation
 85 *
 86 *	Allocates memory for a colormap @cmap.  @len is the
 87 *	number of entries in the palette.
 88 *
 89 *	Returns negative errno on error, or zero on success.
 90 *
 91 */
 92
 93int fb_alloc_cmap_gfp(struct fb_cmap *cmap, int len, int transp, gfp_t flags)
 94{
 95	int size = len * sizeof(u16);
 96	int ret = -ENOMEM;
 97
 98	flags |= __GFP_NOWARN;
 99
100	if (cmap->len != len) {
101		fb_dealloc_cmap(cmap);
102		if (!len)
103			return 0;
104
105		cmap->red = kzalloc(size, flags);
106		if (!cmap->red)
107			goto fail;
108		cmap->green = kzalloc(size, flags);
109		if (!cmap->green)
110			goto fail;
111		cmap->blue = kzalloc(size, flags);
112		if (!cmap->blue)
113			goto fail;
114		if (transp) {
115			cmap->transp = kzalloc(size, flags);
116			if (!cmap->transp)
117				goto fail;
118		} else {
119			cmap->transp = NULL;
120		}
121	}
122	cmap->start = 0;
123	cmap->len = len;
124	ret = fb_copy_cmap(fb_default_cmap(len), cmap);
125	if (ret)
126		goto fail;
127	return 0;
128
129fail:
130	fb_dealloc_cmap(cmap);
131	return ret;
132}
133
134int fb_alloc_cmap(struct fb_cmap *cmap, int len, int transp)
135{
136	return fb_alloc_cmap_gfp(cmap, len, transp, GFP_ATOMIC);
137}
138
139/**
140 *      fb_dealloc_cmap - deallocate a colormap
141 *      @cmap: frame buffer colormap structure
142 *
143 *      Deallocates a colormap that was previously allocated with
144 *      fb_alloc_cmap().
145 *
146 */
147
148void fb_dealloc_cmap(struct fb_cmap *cmap)
149{
150	kfree(cmap->red);
151	kfree(cmap->green);
152	kfree(cmap->blue);
153	kfree(cmap->transp);
154
155	cmap->red = cmap->green = cmap->blue = cmap->transp = NULL;
156	cmap->len = 0;
157}
158
159/**
160 *	fb_copy_cmap - copy a colormap
161 *	@from: frame buffer colormap structure
162 *	@to: frame buffer colormap structure
163 *
164 *	Copy contents of colormap from @from to @to.
165 */
166
167int fb_copy_cmap(const struct fb_cmap *from, struct fb_cmap *to)
168{
169	unsigned int tooff = 0, fromoff = 0;
170	size_t size;
171
172	if (to->start > from->start)
173		fromoff = to->start - from->start;
174	else
175		tooff = from->start - to->start;
176	if (fromoff >= from->len || tooff >= to->len)
177		return -EINVAL;
178
179	size = min_t(size_t, to->len - tooff, from->len - fromoff);
180	if (size == 0)
181		return -EINVAL;
182	size *= sizeof(u16);
183
184	memcpy(to->red+tooff, from->red+fromoff, size);
185	memcpy(to->green+tooff, from->green+fromoff, size);
186	memcpy(to->blue+tooff, from->blue+fromoff, size);
187	if (from->transp && to->transp)
188		memcpy(to->transp+tooff, from->transp+fromoff, size);
189	return 0;
190}
191
192int fb_cmap_to_user(const struct fb_cmap *from, struct fb_cmap_user *to)
193{
194	unsigned int tooff = 0, fromoff = 0;
195	size_t size;
196
197	if (to->start > from->start)
198		fromoff = to->start - from->start;
199	else
200		tooff = from->start - to->start;
201	if (fromoff >= from->len || tooff >= to->len)
202		return -EINVAL;
203
204	size = min_t(size_t, to->len - tooff, from->len - fromoff);
205	if (size == 0)
206		return -EINVAL;
207	size *= sizeof(u16);
208
209	if (copy_to_user(to->red+tooff, from->red+fromoff, size))
210		return -EFAULT;
211	if (copy_to_user(to->green+tooff, from->green+fromoff, size))
212		return -EFAULT;
213	if (copy_to_user(to->blue+tooff, from->blue+fromoff, size))
214		return -EFAULT;
215	if (from->transp && to->transp)
216		if (copy_to_user(to->transp+tooff, from->transp+fromoff, size))
217			return -EFAULT;
218	return 0;
219}
220
221/**
222 *	fb_set_cmap - set the colormap
223 *	@cmap: frame buffer colormap structure
224 *	@info: frame buffer info structure
225 *
226 *	Sets the colormap @cmap for a screen of device @info.
227 *
228 *	Returns negative errno on error, or zero on success.
229 *
230 */
231
232int fb_set_cmap(struct fb_cmap *cmap, struct fb_info *info)
233{
234	int i, start, rc = 0;
235	u16 *red, *green, *blue, *transp;
236	u_int hred, hgreen, hblue, htransp = 0xffff;
237
238	red = cmap->red;
239	green = cmap->green;
240	blue = cmap->blue;
241	transp = cmap->transp;
242	start = cmap->start;
243
244	if (start < 0 || (!info->fbops->fb_setcolreg &&
245			  !info->fbops->fb_setcmap))
246		return -EINVAL;
247	if (info->fbops->fb_setcmap) {
248		rc = info->fbops->fb_setcmap(cmap, info);
249	} else {
250		for (i = 0; i < cmap->len; i++) {
251			hred = *red++;
252			hgreen = *green++;
253			hblue = *blue++;
254			if (transp)
255				htransp = *transp++;
256			if (info->fbops->fb_setcolreg(start++,
257						      hred, hgreen, hblue,
258						      htransp, info))
259				break;
260		}
261	}
262	if (rc == 0)
263		fb_copy_cmap(cmap, &info->cmap);
264
265	return rc;
266}
267
268int fb_set_user_cmap(struct fb_cmap_user *cmap, struct fb_info *info)
269{
270	int rc, size = cmap->len * sizeof(u16);
271	struct fb_cmap umap;
272
273	if (size < 0 || size < cmap->len)
274		return -E2BIG;
275
276	memset(&umap, 0, sizeof(struct fb_cmap));
277	rc = fb_alloc_cmap_gfp(&umap, cmap->len, cmap->transp != NULL,
278				GFP_KERNEL);
279	if (rc)
280		return rc;
281	if (copy_from_user(umap.red, cmap->red, size) ||
282	    copy_from_user(umap.green, cmap->green, size) ||
283	    copy_from_user(umap.blue, cmap->blue, size) ||
284	    (cmap->transp && copy_from_user(umap.transp, cmap->transp, size))) {
285		rc = -EFAULT;
286		goto out;
287	}
288	umap.start = cmap->start;
289	lock_fb_info(info);
290	rc = fb_set_cmap(&umap, info);
291	unlock_fb_info(info);
292out:
293	fb_dealloc_cmap(&umap);
294	return rc;
295}
296
297/**
298 *	fb_default_cmap - get default colormap
299 *	@len: size of palette for a depth
300 *
301 *	Gets the default colormap for a specific screen depth.  @len
302 *	is the size of the palette for a particular screen depth.
303 *
304 *	Returns pointer to a frame buffer colormap structure.
305 *
306 */
307
308const struct fb_cmap *fb_default_cmap(int len)
309{
310    if (len <= 2)
311	return &default_2_colors;
312    if (len <= 4)
313	return &default_4_colors;
314    if (len <= 8)
315	return &default_8_colors;
316    return &default_16_colors;
317}
318
319
320/**
321 *	fb_invert_cmaps - invert all defaults colormaps
322 *
323 *	Invert all default colormaps.
324 *
325 */
326
327void fb_invert_cmaps(void)
328{
329    u_int i;
330
331    for (i = 0; i < ARRAY_SIZE(red2); i++) {
332	red2[i] = ~red2[i];
333	green2[i] = ~green2[i];
334	blue2[i] = ~blue2[i];
335    }
336    for (i = 0; i < ARRAY_SIZE(red4); i++) {
337	red4[i] = ~red4[i];
338	green4[i] = ~green4[i];
339	blue4[i] = ~blue4[i];
340    }
341    for (i = 0; i < ARRAY_SIZE(red8); i++) {
342	red8[i] = ~red8[i];
343	green8[i] = ~green8[i];
344	blue8[i] = ~blue8[i];
345    }
346    for (i = 0; i < ARRAY_SIZE(red16); i++) {
347	red16[i] = ~red16[i];
348	green16[i] = ~green16[i];
349	blue16[i] = ~blue16[i];
350    }
351}
352
353
354    /*
355     *  Visible symbols for modules
356     */
357
358EXPORT_SYMBOL(fb_alloc_cmap);
359EXPORT_SYMBOL(fb_dealloc_cmap);
360EXPORT_SYMBOL(fb_copy_cmap);
361EXPORT_SYMBOL(fb_set_cmap);
362EXPORT_SYMBOL(fb_default_cmap);
363EXPORT_SYMBOL(fb_invert_cmaps);