xref: /openbmc/linux/drivers/video/fbdev/core/svgalib.c (revision 2cf1c348)
1 /*
2  * Common utility functions for VGA-based graphics cards.
3  *
4  * Copyright (c) 2006-2007 Ondrej Zajicek <santiago@crfreenet.org>
5  *
6  * This file is subject to the terms and conditions of the GNU General Public
7  * License.  See the file COPYING in the main directory of this archive for
8  * more details.
9  *
10  * Some parts are based on David Boucher's viafb (http://davesdomain.org.uk/viafb/)
11  */
12 
13 #include <linux/module.h>
14 #include <linux/kernel.h>
15 #include <linux/string.h>
16 #include <linux/fb.h>
17 #include <linux/svga.h>
18 #include <asm/types.h>
19 #include <asm/io.h>
20 
21 
22 /* Write a CRT register value spread across multiple registers */
23 void svga_wcrt_multi(void __iomem *regbase, const struct vga_regset *regset, u32 value)
24 {
25 	u8 regval, bitval, bitnum;
26 
27 	while (regset->regnum != VGA_REGSET_END_VAL) {
28 		regval = vga_rcrt(regbase, regset->regnum);
29 		bitnum = regset->lowbit;
30 		while (bitnum <= regset->highbit) {
31 			bitval = 1 << bitnum;
32 			regval = regval & ~bitval;
33 			if (value & 1) regval = regval | bitval;
34 			bitnum ++;
35 			value = value >> 1;
36 		}
37 		vga_wcrt(regbase, regset->regnum, regval);
38 		regset ++;
39 	}
40 }
41 
42 /* Write a sequencer register value spread across multiple registers */
43 void svga_wseq_multi(void __iomem *regbase, const struct vga_regset *regset, u32 value)
44 {
45 	u8 regval, bitval, bitnum;
46 
47 	while (regset->regnum != VGA_REGSET_END_VAL) {
48 		regval = vga_rseq(regbase, regset->regnum);
49 		bitnum = regset->lowbit;
50 		while (bitnum <= regset->highbit) {
51 			bitval = 1 << bitnum;
52 			regval = regval & ~bitval;
53 			if (value & 1) regval = regval | bitval;
54 			bitnum ++;
55 			value = value >> 1;
56 		}
57 		vga_wseq(regbase, regset->regnum, regval);
58 		regset ++;
59 	}
60 }
61 
62 static unsigned int svga_regset_size(const struct vga_regset *regset)
63 {
64 	u8 count = 0;
65 
66 	while (regset->regnum != VGA_REGSET_END_VAL) {
67 		count += regset->highbit - regset->lowbit + 1;
68 		regset ++;
69 	}
70 	return 1 << count;
71 }
72 
73 
74 /* ------------------------------------------------------------------------- */
75 
76 
77 /* Set graphics controller registers to sane values */
78 void svga_set_default_gfx_regs(void __iomem *regbase)
79 {
80 	/* All standard GFX registers (GR00 - GR08) */
81 	vga_wgfx(regbase, VGA_GFX_SR_VALUE, 0x00);
82 	vga_wgfx(regbase, VGA_GFX_SR_ENABLE, 0x00);
83 	vga_wgfx(regbase, VGA_GFX_COMPARE_VALUE, 0x00);
84 	vga_wgfx(regbase, VGA_GFX_DATA_ROTATE, 0x00);
85 	vga_wgfx(regbase, VGA_GFX_PLANE_READ, 0x00);
86 	vga_wgfx(regbase, VGA_GFX_MODE, 0x00);
87 /*	vga_wgfx(regbase, VGA_GFX_MODE, 0x20); */
88 /*	vga_wgfx(regbase, VGA_GFX_MODE, 0x40); */
89 	vga_wgfx(regbase, VGA_GFX_MISC, 0x05);
90 /*	vga_wgfx(regbase, VGA_GFX_MISC, 0x01); */
91 	vga_wgfx(regbase, VGA_GFX_COMPARE_MASK, 0x0F);
92 	vga_wgfx(regbase, VGA_GFX_BIT_MASK, 0xFF);
93 }
94 
95 /* Set attribute controller registers to sane values */
96 void svga_set_default_atc_regs(void __iomem *regbase)
97 {
98 	u8 count;
99 
100 	vga_r(regbase, 0x3DA);
101 	vga_w(regbase, VGA_ATT_W, 0x00);
102 
103 	/* All standard ATC registers (AR00 - AR14) */
104 	for (count = 0; count <= 0xF; count ++)
105 		svga_wattr(regbase, count, count);
106 
107 	svga_wattr(regbase, VGA_ATC_MODE, 0x01);
108 /*	svga_wattr(regbase, VGA_ATC_MODE, 0x41); */
109 	svga_wattr(regbase, VGA_ATC_OVERSCAN, 0x00);
110 	svga_wattr(regbase, VGA_ATC_PLANE_ENABLE, 0x0F);
111 	svga_wattr(regbase, VGA_ATC_PEL, 0x00);
112 	svga_wattr(regbase, VGA_ATC_COLOR_PAGE, 0x00);
113 
114 	vga_r(regbase, 0x3DA);
115 	vga_w(regbase, VGA_ATT_W, 0x20);
116 }
117 
118 /* Set sequencer registers to sane values */
119 void svga_set_default_seq_regs(void __iomem *regbase)
120 {
121 	/* Standard sequencer registers (SR01 - SR04), SR00 is not set */
122 	vga_wseq(regbase, VGA_SEQ_CLOCK_MODE, VGA_SR01_CHAR_CLK_8DOTS);
123 	vga_wseq(regbase, VGA_SEQ_PLANE_WRITE, VGA_SR02_ALL_PLANES);
124 	vga_wseq(regbase, VGA_SEQ_CHARACTER_MAP, 0x00);
125 /*	vga_wseq(regbase, VGA_SEQ_MEMORY_MODE, VGA_SR04_EXT_MEM | VGA_SR04_SEQ_MODE | VGA_SR04_CHN_4M); */
126 	vga_wseq(regbase, VGA_SEQ_MEMORY_MODE, VGA_SR04_EXT_MEM | VGA_SR04_SEQ_MODE);
127 }
128 
129 /* Set CRTC registers to sane values */
130 void svga_set_default_crt_regs(void __iomem *regbase)
131 {
132 	/* Standard CRT registers CR03 CR08 CR09 CR14 CR17 */
133 	svga_wcrt_mask(regbase, 0x03, 0x80, 0x80);	/* Enable vertical retrace EVRA */
134 	vga_wcrt(regbase, VGA_CRTC_PRESET_ROW, 0);
135 	svga_wcrt_mask(regbase, VGA_CRTC_MAX_SCAN, 0, 0x1F);
136 	vga_wcrt(regbase, VGA_CRTC_UNDERLINE, 0);
137 	vga_wcrt(regbase, VGA_CRTC_MODE, 0xE3);
138 }
139 
140 void svga_set_textmode_vga_regs(void __iomem *regbase)
141 {
142 	/* svga_wseq_mask(regbase, 0x1, 0x00, 0x01); */   /* Switch 8/9 pixel per char */
143 	vga_wseq(regbase, VGA_SEQ_MEMORY_MODE, VGA_SR04_EXT_MEM);
144 	vga_wseq(regbase, VGA_SEQ_PLANE_WRITE, 0x03);
145 
146 	vga_wcrt(regbase, VGA_CRTC_MAX_SCAN, 0x0f); /* 0x4f */
147 	vga_wcrt(regbase, VGA_CRTC_UNDERLINE, 0x1f);
148 	svga_wcrt_mask(regbase, VGA_CRTC_MODE, 0x23, 0x7f);
149 
150 	vga_wcrt(regbase, VGA_CRTC_CURSOR_START, 0x0d);
151 	vga_wcrt(regbase, VGA_CRTC_CURSOR_END, 0x0e);
152 	vga_wcrt(regbase, VGA_CRTC_CURSOR_HI, 0x00);
153 	vga_wcrt(regbase, VGA_CRTC_CURSOR_LO, 0x00);
154 
155 	vga_wgfx(regbase, VGA_GFX_MODE, 0x10); /* Odd/even memory mode */
156 	vga_wgfx(regbase, VGA_GFX_MISC, 0x0E); /* Misc graphics register - text mode enable */
157 	vga_wgfx(regbase, VGA_GFX_COMPARE_MASK, 0x00);
158 
159 	vga_r(regbase, 0x3DA);
160 	vga_w(regbase, VGA_ATT_W, 0x00);
161 
162 	svga_wattr(regbase, 0x10, 0x0C);			/* Attribute Mode Control Register - text mode, blinking and line graphics */
163 	svga_wattr(regbase, 0x13, 0x08);			/* Horizontal Pixel Panning Register  */
164 
165 	vga_r(regbase, 0x3DA);
166 	vga_w(regbase, VGA_ATT_W, 0x20);
167 }
168 
169 #if 0
170 void svga_dump_var(struct fb_var_screeninfo *var, int node)
171 {
172 	pr_debug("fb%d: var.vmode         : 0x%X\n", node, var->vmode);
173 	pr_debug("fb%d: var.xres          : %d\n", node, var->xres);
174 	pr_debug("fb%d: var.yres          : %d\n", node, var->yres);
175 	pr_debug("fb%d: var.bits_per_pixel: %d\n", node, var->bits_per_pixel);
176 	pr_debug("fb%d: var.xres_virtual  : %d\n", node, var->xres_virtual);
177 	pr_debug("fb%d: var.yres_virtual  : %d\n", node, var->yres_virtual);
178 	pr_debug("fb%d: var.left_margin   : %d\n", node, var->left_margin);
179 	pr_debug("fb%d: var.right_margin  : %d\n", node, var->right_margin);
180 	pr_debug("fb%d: var.upper_margin  : %d\n", node, var->upper_margin);
181 	pr_debug("fb%d: var.lower_margin  : %d\n", node, var->lower_margin);
182 	pr_debug("fb%d: var.hsync_len     : %d\n", node, var->hsync_len);
183 	pr_debug("fb%d: var.vsync_len     : %d\n", node, var->vsync_len);
184 	pr_debug("fb%d: var.sync          : 0x%X\n", node, var->sync);
185 	pr_debug("fb%d: var.pixclock      : %d\n\n", node, var->pixclock);
186 }
187 #endif  /*  0  */
188 
189 
190 /* ------------------------------------------------------------------------- */
191 
192 
193 void svga_settile(struct fb_info *info, struct fb_tilemap *map)
194 {
195 	const u8 *font = map->data;
196 	u8 __iomem *fb = (u8 __iomem *)info->screen_base;
197 	int i, c;
198 
199 	if ((map->width != 8) || (map->height != 16) ||
200 	    (map->depth != 1) || (map->length != 256)) {
201 		fb_err(info, "unsupported font parameters: width %d, height %d, depth %d, length %d\n",
202 		       map->width, map->height, map->depth, map->length);
203 		return;
204 	}
205 
206 	fb += 2;
207 	for (c = 0; c < map->length; c++) {
208 		for (i = 0; i < map->height; i++) {
209 			fb_writeb(font[i], fb + i * 4);
210 //			fb[i * 4] = font[i];
211 		}
212 		fb += 128;
213 		font += map->height;
214 	}
215 }
216 
217 /* Copy area in text (tileblit) mode */
218 void svga_tilecopy(struct fb_info *info, struct fb_tilearea *area)
219 {
220 	int dx, dy;
221 	/*  colstride is halved in this function because u16 are used */
222 	int colstride = 1 << (info->fix.type_aux & FB_AUX_TEXT_SVGA_MASK);
223 	int rowstride = colstride * (info->var.xres_virtual / 8);
224 	u16 __iomem *fb = (u16 __iomem *) info->screen_base;
225 	u16 __iomem *src, *dst;
226 
227 	if ((area->sy > area->dy) ||
228 	    ((area->sy == area->dy) && (area->sx > area->dx))) {
229 		src = fb + area->sx * colstride + area->sy * rowstride;
230 		dst = fb + area->dx * colstride + area->dy * rowstride;
231 	    } else {
232 		src = fb + (area->sx + area->width - 1) * colstride
233 			 + (area->sy + area->height - 1) * rowstride;
234 		dst = fb + (area->dx + area->width - 1) * colstride
235 			 + (area->dy + area->height - 1) * rowstride;
236 
237 		colstride = -colstride;
238 		rowstride = -rowstride;
239 	    }
240 
241 	for (dy = 0; dy < area->height; dy++) {
242 		u16 __iomem *src2 = src;
243 		u16 __iomem *dst2 = dst;
244 		for (dx = 0; dx < area->width; dx++) {
245 			fb_writew(fb_readw(src2), dst2);
246 //			*dst2 = *src2;
247 			src2 += colstride;
248 			dst2 += colstride;
249 		}
250 		src += rowstride;
251 		dst += rowstride;
252 	}
253 }
254 
255 /* Fill area in text (tileblit) mode */
256 void svga_tilefill(struct fb_info *info, struct fb_tilerect *rect)
257 {
258 	int dx, dy;
259 	int colstride = 2 << (info->fix.type_aux & FB_AUX_TEXT_SVGA_MASK);
260 	int rowstride = colstride * (info->var.xres_virtual / 8);
261 	int attr = (0x0F & rect->bg) << 4 | (0x0F & rect->fg);
262 	u8 __iomem *fb = (u8 __iomem *)info->screen_base;
263 	fb += rect->sx * colstride + rect->sy * rowstride;
264 
265 	for (dy = 0; dy < rect->height; dy++) {
266 		u8 __iomem *fb2 = fb;
267 		for (dx = 0; dx < rect->width; dx++) {
268 			fb_writeb(rect->index, fb2);
269 			fb_writeb(attr, fb2 + 1);
270 			fb2 += colstride;
271 		}
272 		fb += rowstride;
273 	}
274 }
275 
276 /* Write text in text (tileblit) mode */
277 void svga_tileblit(struct fb_info *info, struct fb_tileblit *blit)
278 {
279 	int dx, dy, i;
280 	int colstride = 2 << (info->fix.type_aux & FB_AUX_TEXT_SVGA_MASK);
281 	int rowstride = colstride * (info->var.xres_virtual / 8);
282 	int attr = (0x0F & blit->bg) << 4 | (0x0F & blit->fg);
283 	u8 __iomem *fb = (u8 __iomem *)info->screen_base;
284 	fb += blit->sx * colstride + blit->sy * rowstride;
285 
286 	i=0;
287 	for (dy=0; dy < blit->height; dy ++) {
288 		u8 __iomem *fb2 = fb;
289 		for (dx = 0; dx < blit->width; dx ++) {
290 			fb_writeb(blit->indices[i], fb2);
291 			fb_writeb(attr, fb2 + 1);
292 			fb2 += colstride;
293 			i ++;
294 			if (i == blit->length) return;
295 		}
296 		fb += rowstride;
297 	}
298 
299 }
300 
301 /* Set cursor in text (tileblit) mode */
302 void svga_tilecursor(void __iomem *regbase, struct fb_info *info, struct fb_tilecursor *cursor)
303 {
304 	u8 cs = 0x0d;
305 	u8 ce = 0x0e;
306 	u16 pos =  cursor->sx + (info->var.xoffset /  8)
307 		+ (cursor->sy + (info->var.yoffset / 16))
308 		   * (info->var.xres_virtual / 8);
309 
310 	if (! cursor -> mode)
311 		return;
312 
313 	svga_wcrt_mask(regbase, 0x0A, 0x20, 0x20); /* disable cursor */
314 
315 	if (cursor -> shape == FB_TILE_CURSOR_NONE)
316 		return;
317 
318 	switch (cursor -> shape) {
319 	case FB_TILE_CURSOR_UNDERLINE:
320 		cs = 0x0d;
321 		break;
322 	case FB_TILE_CURSOR_LOWER_THIRD:
323 		cs = 0x09;
324 		break;
325 	case FB_TILE_CURSOR_LOWER_HALF:
326 		cs = 0x07;
327 		break;
328 	case FB_TILE_CURSOR_TWO_THIRDS:
329 		cs = 0x05;
330 		break;
331 	case FB_TILE_CURSOR_BLOCK:
332 		cs = 0x01;
333 		break;
334 	}
335 
336 	/* set cursor position */
337 	vga_wcrt(regbase, 0x0E, pos >> 8);
338 	vga_wcrt(regbase, 0x0F, pos & 0xFF);
339 
340 	vga_wcrt(regbase, 0x0B, ce); /* set cursor end */
341 	vga_wcrt(regbase, 0x0A, cs); /* set cursor start and enable it */
342 }
343 
344 int svga_get_tilemax(struct fb_info *info)
345 {
346 	return 256;
347 }
348 
349 /* Get capabilities of accelerator based on the mode */
350 
351 void svga_get_caps(struct fb_info *info, struct fb_blit_caps *caps,
352 		   struct fb_var_screeninfo *var)
353 {
354 	if (var->bits_per_pixel == 0) {
355 		/* can only support 256 8x16 bitmap */
356 		caps->x = 1 << (8 - 1);
357 		caps->y = 1 << (16 - 1);
358 		caps->len = 256;
359 	} else {
360 		caps->x = (var->bits_per_pixel == 4) ? 1 << (8 - 1) : ~(u32)0;
361 		caps->y = ~(u32)0;
362 		caps->len = ~(u32)0;
363 	}
364 }
365 EXPORT_SYMBOL(svga_get_caps);
366 
367 /* ------------------------------------------------------------------------- */
368 
369 
370 /*
371  *  Compute PLL settings (M, N, R)
372  *  F_VCO = (F_BASE * M) / N
373  *  F_OUT = F_VCO / (2^R)
374  */
375 
376 static inline u32 abs_diff(u32 a, u32 b)
377 {
378 	return (a > b) ? (a - b) : (b - a);
379 }
380 
381 int svga_compute_pll(const struct svga_pll *pll, u32 f_wanted, u16 *m, u16 *n, u16 *r, int node)
382 {
383 	u16 am, an, ar;
384 	u32 f_vco, f_current, delta_current, delta_best;
385 
386 	pr_debug("fb%d: ideal frequency: %d kHz\n", node, (unsigned int) f_wanted);
387 
388 	ar = pll->r_max;
389 	f_vco = f_wanted << ar;
390 
391 	/* overflow check */
392 	if ((f_vco >> ar) != f_wanted)
393 		return -EINVAL;
394 
395 	/* It is usually better to have greater VCO clock
396 	   because of better frequency stability.
397 	   So first try r_max, then r smaller. */
398 	while ((ar > pll->r_min) && (f_vco > pll->f_vco_max)) {
399 		ar--;
400 		f_vco = f_vco >> 1;
401 	}
402 
403 	/* VCO bounds check */
404 	if ((f_vco < pll->f_vco_min) || (f_vco > pll->f_vco_max))
405 		return -EINVAL;
406 
407 	delta_best = 0xFFFFFFFF;
408 	*m = 0;
409 	*n = 0;
410 	*r = ar;
411 
412 	am = pll->m_min;
413 	an = pll->n_min;
414 
415 	while ((am <= pll->m_max) && (an <= pll->n_max)) {
416 		f_current = (pll->f_base * am) / an;
417 		delta_current = abs_diff (f_current, f_vco);
418 
419 		if (delta_current < delta_best) {
420 			delta_best = delta_current;
421 			*m = am;
422 			*n = an;
423 		}
424 
425 		if (f_current <= f_vco) {
426 			am ++;
427 		} else {
428 			an ++;
429 		}
430 	}
431 
432 	f_current = (pll->f_base * *m) / *n;
433 	pr_debug("fb%d: found frequency: %d kHz (VCO %d kHz)\n", node, (int) (f_current >> ar), (int) f_current);
434 	pr_debug("fb%d: m = %d n = %d r = %d\n", node, (unsigned int) *m, (unsigned int) *n, (unsigned int) *r);
435 	return 0;
436 }
437 
438 
439 /* ------------------------------------------------------------------------- */
440 
441 
442 /* Check CRT timing values */
443 int svga_check_timings(const struct svga_timing_regs *tm, struct fb_var_screeninfo *var, int node)
444 {
445 	u32 value;
446 
447 	var->xres         = (var->xres+7)&~7;
448 	var->left_margin  = (var->left_margin+7)&~7;
449 	var->right_margin = (var->right_margin+7)&~7;
450 	var->hsync_len    = (var->hsync_len+7)&~7;
451 
452 	/* Check horizontal total */
453 	value = var->xres + var->left_margin + var->right_margin + var->hsync_len;
454 	if (((value / 8) - 5) >= svga_regset_size (tm->h_total_regs))
455 		return -EINVAL;
456 
457 	/* Check horizontal display and blank start */
458 	value = var->xres;
459 	if (((value / 8) - 1) >= svga_regset_size (tm->h_display_regs))
460 		return -EINVAL;
461 	if (((value / 8) - 1) >= svga_regset_size (tm->h_blank_start_regs))
462 		return -EINVAL;
463 
464 	/* Check horizontal sync start */
465 	value = var->xres + var->right_margin;
466 	if (((value / 8) - 1) >= svga_regset_size (tm->h_sync_start_regs))
467 		return -EINVAL;
468 
469 	/* Check horizontal blank end (or length) */
470 	value = var->left_margin + var->right_margin + var->hsync_len;
471 	if ((value == 0) || ((value / 8) >= svga_regset_size (tm->h_blank_end_regs)))
472 		return -EINVAL;
473 
474 	/* Check horizontal sync end (or length) */
475 	value = var->hsync_len;
476 	if ((value == 0) || ((value / 8) >= svga_regset_size (tm->h_sync_end_regs)))
477 		return -EINVAL;
478 
479 	/* Check vertical total */
480 	value = var->yres + var->upper_margin + var->lower_margin + var->vsync_len;
481 	if ((value - 1) >= svga_regset_size(tm->v_total_regs))
482 		return -EINVAL;
483 
484 	/* Check vertical display and blank start */
485 	value = var->yres;
486 	if ((value - 1) >= svga_regset_size(tm->v_display_regs))
487 		return -EINVAL;
488 	if ((value - 1) >= svga_regset_size(tm->v_blank_start_regs))
489 		return -EINVAL;
490 
491 	/* Check vertical sync start */
492 	value = var->yres + var->lower_margin;
493 	if ((value - 1) >= svga_regset_size(tm->v_sync_start_regs))
494 		return -EINVAL;
495 
496 	/* Check vertical blank end (or length) */
497 	value = var->upper_margin + var->lower_margin + var->vsync_len;
498 	if ((value == 0) || (value >= svga_regset_size (tm->v_blank_end_regs)))
499 		return -EINVAL;
500 
501 	/* Check vertical sync end  (or length) */
502 	value = var->vsync_len;
503 	if ((value == 0) || (value >= svga_regset_size (tm->v_sync_end_regs)))
504 		return -EINVAL;
505 
506 	return 0;
507 }
508 
509 /* Set CRT timing registers */
510 void svga_set_timings(void __iomem *regbase, const struct svga_timing_regs *tm,
511 		      struct fb_var_screeninfo *var,
512 		      u32 hmul, u32 hdiv, u32 vmul, u32 vdiv, u32 hborder, int node)
513 {
514 	u8 regval;
515 	u32 value;
516 
517 	value = var->xres + var->left_margin + var->right_margin + var->hsync_len;
518 	value = (value * hmul) / hdiv;
519 	pr_debug("fb%d: horizontal total      : %d\n", node, value);
520 	svga_wcrt_multi(regbase, tm->h_total_regs, (value / 8) - 5);
521 
522 	value = var->xres;
523 	value = (value * hmul) / hdiv;
524 	pr_debug("fb%d: horizontal display    : %d\n", node, value);
525 	svga_wcrt_multi(regbase, tm->h_display_regs, (value / 8) - 1);
526 
527 	value = var->xres;
528 	value = (value * hmul) / hdiv;
529 	pr_debug("fb%d: horizontal blank start: %d\n", node, value);
530 	svga_wcrt_multi(regbase, tm->h_blank_start_regs, (value / 8) - 1 + hborder);
531 
532 	value = var->xres + var->left_margin + var->right_margin + var->hsync_len;
533 	value = (value * hmul) / hdiv;
534 	pr_debug("fb%d: horizontal blank end  : %d\n", node, value);
535 	svga_wcrt_multi(regbase, tm->h_blank_end_regs, (value / 8) - 1 - hborder);
536 
537 	value = var->xres + var->right_margin;
538 	value = (value * hmul) / hdiv;
539 	pr_debug("fb%d: horizontal sync start : %d\n", node, value);
540 	svga_wcrt_multi(regbase, tm->h_sync_start_regs, (value / 8));
541 
542 	value = var->xres + var->right_margin + var->hsync_len;
543 	value = (value * hmul) / hdiv;
544 	pr_debug("fb%d: horizontal sync end   : %d\n", node, value);
545 	svga_wcrt_multi(regbase, tm->h_sync_end_regs, (value / 8));
546 
547 	value = var->yres + var->upper_margin + var->lower_margin + var->vsync_len;
548 	value = (value * vmul) / vdiv;
549 	pr_debug("fb%d: vertical total        : %d\n", node, value);
550 	svga_wcrt_multi(regbase, tm->v_total_regs, value - 2);
551 
552 	value = var->yres;
553 	value = (value * vmul) / vdiv;
554 	pr_debug("fb%d: vertical display      : %d\n", node, value);
555 	svga_wcrt_multi(regbase, tm->v_display_regs, value - 1);
556 
557 	value = var->yres;
558 	value = (value * vmul) / vdiv;
559 	pr_debug("fb%d: vertical blank start  : %d\n", node, value);
560 	svga_wcrt_multi(regbase, tm->v_blank_start_regs, value);
561 
562 	value = var->yres + var->upper_margin + var->lower_margin + var->vsync_len;
563 	value = (value * vmul) / vdiv;
564 	pr_debug("fb%d: vertical blank end    : %d\n", node, value);
565 	svga_wcrt_multi(regbase, tm->v_blank_end_regs, value - 2);
566 
567 	value = var->yres + var->lower_margin;
568 	value = (value * vmul) / vdiv;
569 	pr_debug("fb%d: vertical sync start   : %d\n", node, value);
570 	svga_wcrt_multi(regbase, tm->v_sync_start_regs, value);
571 
572 	value = var->yres + var->lower_margin + var->vsync_len;
573 	value = (value * vmul) / vdiv;
574 	pr_debug("fb%d: vertical sync end     : %d\n", node, value);
575 	svga_wcrt_multi(regbase, tm->v_sync_end_regs, value);
576 
577 	/* Set horizontal and vertical sync pulse polarity in misc register */
578 
579 	regval = vga_r(regbase, VGA_MIS_R);
580 	if (var->sync & FB_SYNC_HOR_HIGH_ACT) {
581 		pr_debug("fb%d: positive horizontal sync\n", node);
582 		regval = regval & ~0x80;
583 	} else {
584 		pr_debug("fb%d: negative horizontal sync\n", node);
585 		regval = regval | 0x80;
586 	}
587 	if (var->sync & FB_SYNC_VERT_HIGH_ACT) {
588 		pr_debug("fb%d: positive vertical sync\n", node);
589 		regval = regval & ~0x40;
590 	} else {
591 		pr_debug("fb%d: negative vertical sync\n\n", node);
592 		regval = regval | 0x40;
593 	}
594 	vga_w(regbase, VGA_MIS_W, regval);
595 }
596 
597 
598 /* ------------------------------------------------------------------------- */
599 
600 
601 static inline int match_format(const struct svga_fb_format *frm,
602 			       struct fb_var_screeninfo *var)
603 {
604 	int i = 0;
605 	int stored = -EINVAL;
606 
607 	while (frm->bits_per_pixel != SVGA_FORMAT_END_VAL)
608 	{
609 		if ((var->bits_per_pixel == frm->bits_per_pixel) &&
610 		    (var->red.length     <= frm->red.length)     &&
611 		    (var->green.length   <= frm->green.length)   &&
612 		    (var->blue.length    <= frm->blue.length)    &&
613 		    (var->transp.length  <= frm->transp.length)  &&
614 		    (var->nonstd	 == frm->nonstd))
615 			return i;
616 		if (var->bits_per_pixel == frm->bits_per_pixel)
617 			stored = i;
618 		i++;
619 		frm++;
620 	}
621 	return stored;
622 }
623 
624 int svga_match_format(const struct svga_fb_format *frm,
625 		      struct fb_var_screeninfo *var,
626 		      struct fb_fix_screeninfo *fix)
627 {
628 	int i = match_format(frm, var);
629 
630 	if (i >= 0) {
631 		var->bits_per_pixel = frm[i].bits_per_pixel;
632 		var->red            = frm[i].red;
633 		var->green          = frm[i].green;
634 		var->blue           = frm[i].blue;
635 		var->transp         = frm[i].transp;
636 		var->nonstd         = frm[i].nonstd;
637 		if (fix != NULL) {
638 			fix->type      = frm[i].type;
639 			fix->type_aux  = frm[i].type_aux;
640 			fix->visual    = frm[i].visual;
641 			fix->xpanstep  = frm[i].xpanstep;
642 		}
643 	}
644 
645 	return i;
646 }
647 
648 
649 EXPORT_SYMBOL(svga_wcrt_multi);
650 EXPORT_SYMBOL(svga_wseq_multi);
651 
652 EXPORT_SYMBOL(svga_set_default_gfx_regs);
653 EXPORT_SYMBOL(svga_set_default_atc_regs);
654 EXPORT_SYMBOL(svga_set_default_seq_regs);
655 EXPORT_SYMBOL(svga_set_default_crt_regs);
656 EXPORT_SYMBOL(svga_set_textmode_vga_regs);
657 
658 EXPORT_SYMBOL(svga_settile);
659 EXPORT_SYMBOL(svga_tilecopy);
660 EXPORT_SYMBOL(svga_tilefill);
661 EXPORT_SYMBOL(svga_tileblit);
662 EXPORT_SYMBOL(svga_tilecursor);
663 EXPORT_SYMBOL(svga_get_tilemax);
664 
665 EXPORT_SYMBOL(svga_compute_pll);
666 EXPORT_SYMBOL(svga_check_timings);
667 EXPORT_SYMBOL(svga_set_timings);
668 EXPORT_SYMBOL(svga_match_format);
669 
670 MODULE_AUTHOR("Ondrej Zajicek <santiago@crfreenet.org>");
671 MODULE_DESCRIPTION("Common utility functions for VGA-based graphics cards");
672 MODULE_LICENSE("GPL");
673