1 /*
2  *  Generic 1-bit or 8-bit source to 1-32 bit destination expansion
3  *  for frame buffer located in system RAM with packed pixels of any depth.
4  *
5  *  Based almost entirely on cfbimgblt.c
6  *
7  *      Copyright (C)  April 2007 Antonino Daplas <adaplas@pol.net>
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 #include <linux/module.h>
14 #include <linux/string.h>
15 #include <linux/fb.h>
16 #include <asm/types.h>
17 
18 #define DEBUG
19 
20 #ifdef DEBUG
21 #define DPRINTK(fmt, args...) printk(KERN_DEBUG "%s: " fmt,__func__,## args)
22 #else
23 #define DPRINTK(fmt, args...)
24 #endif
25 
26 static const u32 cfb_tab8_be[] = {
27     0x00000000,0x000000ff,0x0000ff00,0x0000ffff,
28     0x00ff0000,0x00ff00ff,0x00ffff00,0x00ffffff,
29     0xff000000,0xff0000ff,0xff00ff00,0xff00ffff,
30     0xffff0000,0xffff00ff,0xffffff00,0xffffffff
31 };
32 
33 static const u32 cfb_tab8_le[] = {
34     0x00000000,0xff000000,0x00ff0000,0xffff0000,
35     0x0000ff00,0xff00ff00,0x00ffff00,0xffffff00,
36     0x000000ff,0xff0000ff,0x00ff00ff,0xffff00ff,
37     0x0000ffff,0xff00ffff,0x00ffffff,0xffffffff
38 };
39 
40 static const u32 cfb_tab16_be[] = {
41     0x00000000, 0x0000ffff, 0xffff0000, 0xffffffff
42 };
43 
44 static const u32 cfb_tab16_le[] = {
45     0x00000000, 0xffff0000, 0x0000ffff, 0xffffffff
46 };
47 
48 static const u32 cfb_tab32[] = {
49 	0x00000000, 0xffffffff
50 };
51 
52 static void color_imageblit(const struct fb_image *image, struct fb_info *p,
53 			    void *dst1, u32 start_index, u32 pitch_index)
54 {
55 	/* Draw the penguin */
56 	u32 *dst, *dst2;
57 	u32 color = 0, val, shift;
58 	int i, n, bpp = p->var.bits_per_pixel;
59 	u32 null_bits = 32 - bpp;
60 	u32 *palette = (u32 *) p->pseudo_palette;
61 	const u8 *src = image->data;
62 
63 	dst2 = dst1;
64 	for (i = image->height; i--; ) {
65 		n = image->width;
66 		dst = dst1;
67 		shift = 0;
68 		val = 0;
69 
70 		if (start_index) {
71 			u32 start_mask = ~(FB_SHIFT_HIGH(p, ~(u32)0,
72 							 start_index));
73 			val = *dst & start_mask;
74 			shift = start_index;
75 		}
76 		while (n--) {
77 			if (p->fix.visual == FB_VISUAL_TRUECOLOR ||
78 			    p->fix.visual == FB_VISUAL_DIRECTCOLOR )
79 				color = palette[*src];
80 			else
81 				color = *src;
82 			color <<= FB_LEFT_POS(p, bpp);
83 			val |= FB_SHIFT_HIGH(p, color, shift);
84 			if (shift >= null_bits) {
85 				*dst++ = val;
86 
87 				val = (shift == null_bits) ? 0 :
88 					FB_SHIFT_LOW(p, color, 32 - shift);
89 			}
90 			shift += bpp;
91 			shift &= (32 - 1);
92 			src++;
93 		}
94 		if (shift) {
95 			u32 end_mask = FB_SHIFT_HIGH(p, ~(u32)0, shift);
96 
97 			*dst &= end_mask;
98 			*dst |= val;
99 		}
100 		dst1 += p->fix.line_length;
101 		if (pitch_index) {
102 			dst2 += p->fix.line_length;
103 			dst1 = (u8 *)((long)dst2 & ~(sizeof(u32) - 1));
104 
105 			start_index += pitch_index;
106 			start_index &= 32 - 1;
107 		}
108 	}
109 }
110 
111 static void slow_imageblit(const struct fb_image *image, struct fb_info *p,
112 				  void *dst1, u32 fgcolor, u32 bgcolor,
113 				  u32 start_index, u32 pitch_index)
114 {
115 	u32 shift, color = 0, bpp = p->var.bits_per_pixel;
116 	u32 *dst, *dst2;
117 	u32 val, pitch = p->fix.line_length;
118 	u32 null_bits = 32 - bpp;
119 	u32 spitch = (image->width+7)/8;
120 	const u8 *src = image->data, *s;
121 	u32 i, j, l;
122 
123 	dst2 = dst1;
124 	fgcolor <<= FB_LEFT_POS(p, bpp);
125 	bgcolor <<= FB_LEFT_POS(p, bpp);
126 
127 	for (i = image->height; i--; ) {
128 		shift = val = 0;
129 		l = 8;
130 		j = image->width;
131 		dst = dst1;
132 		s = src;
133 
134 		/* write leading bits */
135 		if (start_index) {
136 			u32 start_mask = ~(FB_SHIFT_HIGH(p, ~(u32)0,
137 							 start_index));
138 			val = *dst & start_mask;
139 			shift = start_index;
140 		}
141 
142 		while (j--) {
143 			l--;
144 			color = (*s & (1 << l)) ? fgcolor : bgcolor;
145 			val |= FB_SHIFT_HIGH(p, color, shift);
146 
147 			/* Did the bitshift spill bits to the next long? */
148 			if (shift >= null_bits) {
149 				*dst++ = val;
150 				val = (shift == null_bits) ? 0 :
151 					FB_SHIFT_LOW(p, color, 32 - shift);
152 			}
153 			shift += bpp;
154 			shift &= (32 - 1);
155 			if (!l) { l = 8; s++; }
156 		}
157 
158 		/* write trailing bits */
159  		if (shift) {
160 			u32 end_mask = FB_SHIFT_HIGH(p, ~(u32)0, shift);
161 
162 			*dst &= end_mask;
163 			*dst |= val;
164 		}
165 
166 		dst1 += pitch;
167 		src += spitch;
168 		if (pitch_index) {
169 			dst2 += pitch;
170 			dst1 = (u8 *)((long)dst2 & ~(sizeof(u32) - 1));
171 			start_index += pitch_index;
172 			start_index &= 32 - 1;
173 		}
174 
175 	}
176 }
177 
178 /*
179  * fast_imageblit - optimized monochrome color expansion
180  *
181  * Only if:  bits_per_pixel == 8, 16, or 32
182  *           image->width is divisible by pixel/dword (ppw);
183  *           fix->line_legth is divisible by 4;
184  *           beginning and end of a scanline is dword aligned
185  */
186 static void fast_imageblit(const struct fb_image *image, struct fb_info *p,
187 				  void *dst1, u32 fgcolor, u32 bgcolor)
188 {
189 	u32 fgx = fgcolor, bgx = bgcolor, bpp = p->var.bits_per_pixel;
190 	u32 ppw = 32/bpp, spitch = (image->width + 7)/8;
191 	u32 bit_mask, eorx, shift;
192 	const u8 *s = image->data, *src;
193 	u32 *dst;
194 	const u32 *tab;
195 	size_t tablen;
196 	u32 colortab[16];
197 	int i, j, k;
198 
199 	switch (bpp) {
200 	case 8:
201 		tab = fb_be_math(p) ? cfb_tab8_be : cfb_tab8_le;
202 		tablen = 16;
203 		break;
204 	case 16:
205 		tab = fb_be_math(p) ? cfb_tab16_be : cfb_tab16_le;
206 		tablen = 4;
207 		break;
208 	case 32:
209 		tab = cfb_tab32;
210 		tablen = 2;
211 		break;
212 	default:
213 		return;
214 	}
215 
216 	for (i = ppw-1; i--; ) {
217 		fgx <<= bpp;
218 		bgx <<= bpp;
219 		fgx |= fgcolor;
220 		bgx |= bgcolor;
221 	}
222 
223 	bit_mask = (1 << ppw) - 1;
224 	eorx = fgx ^ bgx;
225 	k = image->width/ppw;
226 
227 	for (i = 0; i < tablen; ++i)
228 		colortab[i] = (tab[i] & eorx) ^ bgx;
229 
230 	for (i = image->height; i--; ) {
231 		dst = dst1;
232 		shift = 8;
233 		src = s;
234 
235 		/*
236 		 * Manually unroll the per-line copying loop for better
237 		 * performance. This works until we processed the last
238 		 * completely filled source byte (inclusive).
239 		 */
240 		switch (ppw) {
241 		case 4: /* 8 bpp */
242 			for (j = k; j >= 2; j -= 2, ++src) {
243 				*dst++ = colortab[(*src >> 4) & bit_mask];
244 				*dst++ = colortab[(*src >> 0) & bit_mask];
245 			}
246 			break;
247 		case 2: /* 16 bpp */
248 			for (j = k; j >= 4; j -= 4, ++src) {
249 				*dst++ = colortab[(*src >> 6) & bit_mask];
250 				*dst++ = colortab[(*src >> 4) & bit_mask];
251 				*dst++ = colortab[(*src >> 2) & bit_mask];
252 				*dst++ = colortab[(*src >> 0) & bit_mask];
253 			}
254 			break;
255 		case 1: /* 32 bpp */
256 			for (j = k; j >= 8; j -= 8, ++src) {
257 				*dst++ = colortab[(*src >> 7) & bit_mask];
258 				*dst++ = colortab[(*src >> 6) & bit_mask];
259 				*dst++ = colortab[(*src >> 5) & bit_mask];
260 				*dst++ = colortab[(*src >> 4) & bit_mask];
261 				*dst++ = colortab[(*src >> 3) & bit_mask];
262 				*dst++ = colortab[(*src >> 2) & bit_mask];
263 				*dst++ = colortab[(*src >> 1) & bit_mask];
264 				*dst++ = colortab[(*src >> 0) & bit_mask];
265 			}
266 			break;
267 		}
268 
269 		/*
270 		 * For image widths that are not a multiple of 8, there
271 		 * are trailing pixels left on the current line. Print
272 		 * them as well.
273 		 */
274 		for (; j--; ) {
275 			shift -= ppw;
276 			*dst++ = colortab[(*src >> shift) & bit_mask];
277 			if (!shift) {
278 				shift = 8;
279 				++src;
280 			}
281 		}
282 
283 		dst1 += p->fix.line_length;
284 		s += spitch;
285 	}
286 }
287 
288 void sys_imageblit(struct fb_info *p, const struct fb_image *image)
289 {
290 	u32 fgcolor, bgcolor, start_index, bitstart, pitch_index = 0;
291 	u32 bpl = sizeof(u32), bpp = p->var.bits_per_pixel;
292 	u32 width = image->width;
293 	u32 dx = image->dx, dy = image->dy;
294 	void *dst1;
295 
296 	if (p->state != FBINFO_STATE_RUNNING)
297 		return;
298 
299 	bitstart = (dy * p->fix.line_length * 8) + (dx * bpp);
300 	start_index = bitstart & (32 - 1);
301 	pitch_index = (p->fix.line_length & (bpl - 1)) * 8;
302 
303 	bitstart /= 8;
304 	bitstart &= ~(bpl - 1);
305 	dst1 = (void __force *)p->screen_base + bitstart;
306 
307 	if (p->fbops->fb_sync)
308 		p->fbops->fb_sync(p);
309 
310 	if (image->depth == 1) {
311 		if (p->fix.visual == FB_VISUAL_TRUECOLOR ||
312 		    p->fix.visual == FB_VISUAL_DIRECTCOLOR) {
313 			fgcolor = ((u32*)(p->pseudo_palette))[image->fg_color];
314 			bgcolor = ((u32*)(p->pseudo_palette))[image->bg_color];
315 		} else {
316 			fgcolor = image->fg_color;
317 			bgcolor = image->bg_color;
318 		}
319 
320 		if (32 % bpp == 0 && !start_index && !pitch_index &&
321 		    ((width & (32/bpp-1)) == 0) &&
322 		    bpp >= 8 && bpp <= 32)
323 			fast_imageblit(image, p, dst1, fgcolor, bgcolor);
324 		else
325 			slow_imageblit(image, p, dst1, fgcolor, bgcolor,
326 					start_index, pitch_index);
327 	} else
328 		color_imageblit(image, p, dst1, start_index, pitch_index);
329 }
330 
331 EXPORT_SYMBOL(sys_imageblit);
332 
333 MODULE_AUTHOR("Antonino Daplas <adaplas@pol.net>");
334 MODULE_DESCRIPTION("1-bit/8-bit to 1-32 bit color expansion (sys-to-sys)");
335 MODULE_LICENSE("GPL");
336 
337