xref: /linux/drivers/video/fbdev/core/fbmon.c (revision 2ba9268dd603d23e17643437b2246acb6844953b)
1 /*
2  * linux/drivers/video/fbmon.c
3  *
4  * Copyright (C) 2002 James Simmons <jsimmons@users.sf.net>
5  *
6  * Credits:
7  *
8  * The EDID Parser is a conglomeration from the following sources:
9  *
10  *   1. SciTech SNAP Graphics Architecture
11  *      Copyright (C) 1991-2002 SciTech Software, Inc. All rights reserved.
12  *
13  *   2. XFree86 4.3.0, interpret_edid.c
14  *      Copyright 1998 by Egbert Eich <Egbert.Eich@Physik.TU-Darmstadt.DE>
15  *
16  *   3. John Fremlin <vii@users.sourceforge.net> and
17  *      Ani Joshi <ajoshi@unixbox.com>
18  *
19  * Generalized Timing Formula is derived from:
20  *
21  *      GTF Spreadsheet by Andy Morrish (1/5/97)
22  *      available at http://www.vesa.org
23  *
24  * This file is subject to the terms and conditions of the GNU General Public
25  * License.  See the file COPYING in the main directory of this archive
26  * for more details.
27  *
28  */
29 #include <linux/fb.h>
30 #include <linux/module.h>
31 #include <linux/pci.h>
32 #include <linux/slab.h>
33 #include <video/edid.h>
34 #include <video/of_videomode.h>
35 #include <video/videomode.h>
36 #ifdef CONFIG_PPC_OF
37 #include <asm/prom.h>
38 #include <asm/pci-bridge.h>
39 #endif
40 #include "../edid.h"
41 
42 /*
43  * EDID parser
44  */
45 
46 #undef DEBUG  /* define this for verbose EDID parsing output */
47 
48 #ifdef DEBUG
49 #define DPRINTK(fmt, args...) printk(fmt,## args)
50 #else
51 #define DPRINTK(fmt, args...)
52 #endif
53 
54 #define FBMON_FIX_HEADER  1
55 #define FBMON_FIX_INPUT   2
56 #define FBMON_FIX_TIMINGS 3
57 
58 #ifdef CONFIG_FB_MODE_HELPERS
59 struct broken_edid {
60 	u8  manufacturer[4];
61 	u32 model;
62 	u32 fix;
63 };
64 
65 static const struct broken_edid brokendb[] = {
66 	/* DEC FR-PCXAV-YZ */
67 	{
68 		.manufacturer = "DEC",
69 		.model        = 0x073a,
70 		.fix          = FBMON_FIX_HEADER,
71 	},
72 	/* ViewSonic PF775a */
73 	{
74 		.manufacturer = "VSC",
75 		.model        = 0x5a44,
76 		.fix          = FBMON_FIX_INPUT,
77 	},
78 	/* Sharp UXGA? */
79 	{
80 		.manufacturer = "SHP",
81 		.model        = 0x138e,
82 		.fix          = FBMON_FIX_TIMINGS,
83 	},
84 };
85 
86 static const unsigned char edid_v1_header[] = { 0x00, 0xff, 0xff, 0xff,
87 	0xff, 0xff, 0xff, 0x00
88 };
89 
90 static void copy_string(unsigned char *c, unsigned char *s)
91 {
92   int i;
93   c = c + 5;
94   for (i = 0; (i < 13 && *c != 0x0A); i++)
95     *(s++) = *(c++);
96   *s = 0;
97   while (i-- && (*--s == 0x20)) *s = 0;
98 }
99 
100 static int edid_is_serial_block(unsigned char *block)
101 {
102 	if ((block[0] == 0x00) && (block[1] == 0x00) &&
103 	    (block[2] == 0x00) && (block[3] == 0xff) &&
104 	    (block[4] == 0x00))
105 		return 1;
106 	else
107 		return 0;
108 }
109 
110 static int edid_is_ascii_block(unsigned char *block)
111 {
112 	if ((block[0] == 0x00) && (block[1] == 0x00) &&
113 	    (block[2] == 0x00) && (block[3] == 0xfe) &&
114 	    (block[4] == 0x00))
115 		return 1;
116 	else
117 		return 0;
118 }
119 
120 static int edid_is_limits_block(unsigned char *block)
121 {
122 	if ((block[0] == 0x00) && (block[1] == 0x00) &&
123 	    (block[2] == 0x00) && (block[3] == 0xfd) &&
124 	    (block[4] == 0x00))
125 		return 1;
126 	else
127 		return 0;
128 }
129 
130 static int edid_is_monitor_block(unsigned char *block)
131 {
132 	if ((block[0] == 0x00) && (block[1] == 0x00) &&
133 	    (block[2] == 0x00) && (block[3] == 0xfc) &&
134 	    (block[4] == 0x00))
135 		return 1;
136 	else
137 		return 0;
138 }
139 
140 static int edid_is_timing_block(unsigned char *block)
141 {
142 	if ((block[0] != 0x00) || (block[1] != 0x00) ||
143 	    (block[2] != 0x00) || (block[4] != 0x00))
144 		return 1;
145 	else
146 		return 0;
147 }
148 
149 static int check_edid(unsigned char *edid)
150 {
151 	unsigned char *block = edid + ID_MANUFACTURER_NAME, manufacturer[4];
152 	unsigned char *b;
153 	u32 model;
154 	int i, fix = 0, ret = 0;
155 
156 	manufacturer[0] = ((block[0] & 0x7c) >> 2) + '@';
157 	manufacturer[1] = ((block[0] & 0x03) << 3) +
158 		((block[1] & 0xe0) >> 5) + '@';
159 	manufacturer[2] = (block[1] & 0x1f) + '@';
160 	manufacturer[3] = 0;
161 	model = block[2] + (block[3] << 8);
162 
163 	for (i = 0; i < ARRAY_SIZE(brokendb); i++) {
164 		if (!strncmp(manufacturer, brokendb[i].manufacturer, 4) &&
165 			brokendb[i].model == model) {
166 			fix = brokendb[i].fix;
167 			break;
168 		}
169 	}
170 
171 	switch (fix) {
172 	case FBMON_FIX_HEADER:
173 		for (i = 0; i < 8; i++) {
174 			if (edid[i] != edid_v1_header[i]) {
175 				ret = fix;
176 				break;
177 			}
178 		}
179 		break;
180 	case FBMON_FIX_INPUT:
181 		b = edid + EDID_STRUCT_DISPLAY;
182 		/* Only if display is GTF capable will
183 		   the input type be reset to analog */
184 		if (b[4] & 0x01 && b[0] & 0x80)
185 			ret = fix;
186 		break;
187 	case FBMON_FIX_TIMINGS:
188 		b = edid + DETAILED_TIMING_DESCRIPTIONS_START;
189 		ret = fix;
190 
191 		for (i = 0; i < 4; i++) {
192 			if (edid_is_limits_block(b)) {
193 				ret = 0;
194 				break;
195 			}
196 
197 			b += DETAILED_TIMING_DESCRIPTION_SIZE;
198 		}
199 
200 		break;
201 	}
202 
203 	if (ret)
204 		printk("fbmon: The EDID Block of "
205 		       "Manufacturer: %s Model: 0x%x is known to "
206 		       "be broken,\n",  manufacturer, model);
207 
208 	return ret;
209 }
210 
211 static void fix_edid(unsigned char *edid, int fix)
212 {
213 	int i;
214 	unsigned char *b, csum = 0;
215 
216 	switch (fix) {
217 	case FBMON_FIX_HEADER:
218 		printk("fbmon: trying a header reconstruct\n");
219 		memcpy(edid, edid_v1_header, 8);
220 		break;
221 	case FBMON_FIX_INPUT:
222 		printk("fbmon: trying to fix input type\n");
223 		b = edid + EDID_STRUCT_DISPLAY;
224 		b[0] &= ~0x80;
225 		edid[127] += 0x80;
226 		break;
227 	case FBMON_FIX_TIMINGS:
228 		printk("fbmon: trying to fix monitor timings\n");
229 		b = edid + DETAILED_TIMING_DESCRIPTIONS_START;
230 		for (i = 0; i < 4; i++) {
231 			if (!(edid_is_serial_block(b) ||
232 			      edid_is_ascii_block(b) ||
233 			      edid_is_monitor_block(b) ||
234 			      edid_is_timing_block(b))) {
235 				b[0] = 0x00;
236 				b[1] = 0x00;
237 				b[2] = 0x00;
238 				b[3] = 0xfd;
239 				b[4] = 0x00;
240 				b[5] = 60;   /* vfmin */
241 				b[6] = 60;   /* vfmax */
242 				b[7] = 30;   /* hfmin */
243 				b[8] = 75;   /* hfmax */
244 				b[9] = 17;   /* pixclock - 170 MHz*/
245 				b[10] = 0;   /* GTF */
246 				break;
247 			}
248 
249 			b += DETAILED_TIMING_DESCRIPTION_SIZE;
250 		}
251 
252 		for (i = 0; i < EDID_LENGTH - 1; i++)
253 			csum += edid[i];
254 
255 		edid[127] = 256 - csum;
256 		break;
257 	}
258 }
259 
260 static int edid_checksum(unsigned char *edid)
261 {
262 	unsigned char csum = 0, all_null = 0;
263 	int i, err = 0, fix = check_edid(edid);
264 
265 	if (fix)
266 		fix_edid(edid, fix);
267 
268 	for (i = 0; i < EDID_LENGTH; i++) {
269 		csum += edid[i];
270 		all_null |= edid[i];
271 	}
272 
273 	if (csum == 0x00 && all_null) {
274 		/* checksum passed, everything's good */
275 		err = 1;
276 	}
277 
278 	return err;
279 }
280 
281 static int edid_check_header(unsigned char *edid)
282 {
283 	int i, err = 1, fix = check_edid(edid);
284 
285 	if (fix)
286 		fix_edid(edid, fix);
287 
288 	for (i = 0; i < 8; i++) {
289 		if (edid[i] != edid_v1_header[i])
290 			err = 0;
291 	}
292 
293 	return err;
294 }
295 
296 static void parse_vendor_block(unsigned char *block, struct fb_monspecs *specs)
297 {
298 	specs->manufacturer[0] = ((block[0] & 0x7c) >> 2) + '@';
299 	specs->manufacturer[1] = ((block[0] & 0x03) << 3) +
300 		((block[1] & 0xe0) >> 5) + '@';
301 	specs->manufacturer[2] = (block[1] & 0x1f) + '@';
302 	specs->manufacturer[3] = 0;
303 	specs->model = block[2] + (block[3] << 8);
304 	specs->serial = block[4] + (block[5] << 8) +
305 	       (block[6] << 16) + (block[7] << 24);
306 	specs->year = block[9] + 1990;
307 	specs->week = block[8];
308 	DPRINTK("   Manufacturer: %s\n", specs->manufacturer);
309 	DPRINTK("   Model: %x\n", specs->model);
310 	DPRINTK("   Serial#: %u\n", specs->serial);
311 	DPRINTK("   Year: %u Week %u\n", specs->year, specs->week);
312 }
313 
314 static void get_dpms_capabilities(unsigned char flags,
315 				  struct fb_monspecs *specs)
316 {
317 	specs->dpms = 0;
318 	if (flags & DPMS_ACTIVE_OFF)
319 		specs->dpms |= FB_DPMS_ACTIVE_OFF;
320 	if (flags & DPMS_SUSPEND)
321 		specs->dpms |= FB_DPMS_SUSPEND;
322 	if (flags & DPMS_STANDBY)
323 		specs->dpms |= FB_DPMS_STANDBY;
324 	DPRINTK("      DPMS: Active %s, Suspend %s, Standby %s\n",
325 	       (flags & DPMS_ACTIVE_OFF) ? "yes" : "no",
326 	       (flags & DPMS_SUSPEND)    ? "yes" : "no",
327 	       (flags & DPMS_STANDBY)    ? "yes" : "no");
328 }
329 
330 static void get_chroma(unsigned char *block, struct fb_monspecs *specs)
331 {
332 	int tmp;
333 
334 	DPRINTK("      Chroma\n");
335 	/* Chromaticity data */
336 	tmp = ((block[5] & (3 << 6)) >> 6) | (block[0x7] << 2);
337 	tmp *= 1000;
338 	tmp += 512;
339 	specs->chroma.redx = tmp/1024;
340 	DPRINTK("         RedX:     0.%03d ", specs->chroma.redx);
341 
342 	tmp = ((block[5] & (3 << 4)) >> 4) | (block[0x8] << 2);
343 	tmp *= 1000;
344 	tmp += 512;
345 	specs->chroma.redy = tmp/1024;
346 	DPRINTK("RedY:     0.%03d\n", specs->chroma.redy);
347 
348 	tmp = ((block[5] & (3 << 2)) >> 2) | (block[0x9] << 2);
349 	tmp *= 1000;
350 	tmp += 512;
351 	specs->chroma.greenx = tmp/1024;
352 	DPRINTK("         GreenX:   0.%03d ", specs->chroma.greenx);
353 
354 	tmp = (block[5] & 3) | (block[0xa] << 2);
355 	tmp *= 1000;
356 	tmp += 512;
357 	specs->chroma.greeny = tmp/1024;
358 	DPRINTK("GreenY:   0.%03d\n", specs->chroma.greeny);
359 
360 	tmp = ((block[6] & (3 << 6)) >> 6) | (block[0xb] << 2);
361 	tmp *= 1000;
362 	tmp += 512;
363 	specs->chroma.bluex = tmp/1024;
364 	DPRINTK("         BlueX:    0.%03d ", specs->chroma.bluex);
365 
366 	tmp = ((block[6] & (3 << 4)) >> 4) | (block[0xc] << 2);
367 	tmp *= 1000;
368 	tmp += 512;
369 	specs->chroma.bluey = tmp/1024;
370 	DPRINTK("BlueY:    0.%03d\n", specs->chroma.bluey);
371 
372 	tmp = ((block[6] & (3 << 2)) >> 2) | (block[0xd] << 2);
373 	tmp *= 1000;
374 	tmp += 512;
375 	specs->chroma.whitex = tmp/1024;
376 	DPRINTK("         WhiteX:   0.%03d ", specs->chroma.whitex);
377 
378 	tmp = (block[6] & 3) | (block[0xe] << 2);
379 	tmp *= 1000;
380 	tmp += 512;
381 	specs->chroma.whitey = tmp/1024;
382 	DPRINTK("WhiteY:   0.%03d\n", specs->chroma.whitey);
383 }
384 
385 static void calc_mode_timings(int xres, int yres, int refresh,
386 			      struct fb_videomode *mode)
387 {
388 	struct fb_var_screeninfo *var;
389 
390 	var = kzalloc(sizeof(struct fb_var_screeninfo), GFP_KERNEL);
391 
392 	if (var) {
393 		var->xres = xres;
394 		var->yres = yres;
395 		fb_get_mode(FB_VSYNCTIMINGS | FB_IGNOREMON,
396 			    refresh, var, NULL);
397 		mode->xres = xres;
398 		mode->yres = yres;
399 		mode->pixclock = var->pixclock;
400 		mode->refresh = refresh;
401 		mode->left_margin = var->left_margin;
402 		mode->right_margin = var->right_margin;
403 		mode->upper_margin = var->upper_margin;
404 		mode->lower_margin = var->lower_margin;
405 		mode->hsync_len = var->hsync_len;
406 		mode->vsync_len = var->vsync_len;
407 		mode->vmode = 0;
408 		mode->sync = 0;
409 		kfree(var);
410 	}
411 }
412 
413 static int get_est_timing(unsigned char *block, struct fb_videomode *mode)
414 {
415 	int num = 0;
416 	unsigned char c;
417 
418 	c = block[0];
419 	if (c&0x80) {
420 		calc_mode_timings(720, 400, 70, &mode[num]);
421 		mode[num++].flag = FB_MODE_IS_CALCULATED;
422 		DPRINTK("      720x400@70Hz\n");
423 	}
424 	if (c&0x40) {
425 		calc_mode_timings(720, 400, 88, &mode[num]);
426 		mode[num++].flag = FB_MODE_IS_CALCULATED;
427 		DPRINTK("      720x400@88Hz\n");
428 	}
429 	if (c&0x20) {
430 		mode[num++] = vesa_modes[3];
431 		DPRINTK("      640x480@60Hz\n");
432 	}
433 	if (c&0x10) {
434 		calc_mode_timings(640, 480, 67, &mode[num]);
435 		mode[num++].flag = FB_MODE_IS_CALCULATED;
436 		DPRINTK("      640x480@67Hz\n");
437 	}
438 	if (c&0x08) {
439 		mode[num++] = vesa_modes[4];
440 		DPRINTK("      640x480@72Hz\n");
441 	}
442 	if (c&0x04) {
443 		mode[num++] = vesa_modes[5];
444 		DPRINTK("      640x480@75Hz\n");
445 	}
446 	if (c&0x02) {
447 		mode[num++] = vesa_modes[7];
448 		DPRINTK("      800x600@56Hz\n");
449 	}
450 	if (c&0x01) {
451 		mode[num++] = vesa_modes[8];
452 		DPRINTK("      800x600@60Hz\n");
453 	}
454 
455 	c = block[1];
456 	if (c&0x80) {
457 		mode[num++] = vesa_modes[9];
458 		DPRINTK("      800x600@72Hz\n");
459 	}
460 	if (c&0x40) {
461 		mode[num++] = vesa_modes[10];
462 		DPRINTK("      800x600@75Hz\n");
463 	}
464 	if (c&0x20) {
465 		calc_mode_timings(832, 624, 75, &mode[num]);
466 		mode[num++].flag = FB_MODE_IS_CALCULATED;
467 		DPRINTK("      832x624@75Hz\n");
468 	}
469 	if (c&0x10) {
470 		mode[num++] = vesa_modes[12];
471 		DPRINTK("      1024x768@87Hz Interlaced\n");
472 	}
473 	if (c&0x08) {
474 		mode[num++] = vesa_modes[13];
475 		DPRINTK("      1024x768@60Hz\n");
476 	}
477 	if (c&0x04) {
478 		mode[num++] = vesa_modes[14];
479 		DPRINTK("      1024x768@70Hz\n");
480 	}
481 	if (c&0x02) {
482 		mode[num++] = vesa_modes[15];
483 		DPRINTK("      1024x768@75Hz\n");
484 	}
485 	if (c&0x01) {
486 		mode[num++] = vesa_modes[21];
487 		DPRINTK("      1280x1024@75Hz\n");
488 	}
489 	c = block[2];
490 	if (c&0x80) {
491 		mode[num++] = vesa_modes[17];
492 		DPRINTK("      1152x870@75Hz\n");
493 	}
494 	DPRINTK("      Manufacturer's mask: %x\n",c&0x7F);
495 	return num;
496 }
497 
498 static int get_std_timing(unsigned char *block, struct fb_videomode *mode,
499 			  int ver, int rev, const struct fb_monspecs *specs)
500 {
501 	int i;
502 
503 	for (i = 0; i < DMT_SIZE; i++) {
504 		u32 std_2byte_code = block[0] << 8 | block[1];
505 		if (std_2byte_code == dmt_modes[i].std_2byte_code)
506 			break;
507 	}
508 
509 	if (i < DMT_SIZE && dmt_modes[i].mode) {
510 		/* DMT mode found */
511 		*mode = *dmt_modes[i].mode;
512 		mode->flag |= FB_MODE_IS_STANDARD;
513 		DPRINTK("        DMT id=%d\n", dmt_modes[i].dmt_id);
514 
515 	} else {
516 		int xres, yres = 0, refresh, ratio;
517 
518 		xres = (block[0] + 31) * 8;
519 		if (xres <= 256)
520 			return 0;
521 
522 		ratio = (block[1] & 0xc0) >> 6;
523 		switch (ratio) {
524 		case 0:
525 			/* in EDID 1.3 the meaning of 0 changed to 16:10 (prior 1:1) */
526 			if (ver < 1 || (ver == 1 && rev < 3))
527 				yres = xres;
528 			else
529 				yres = (xres * 10)/16;
530 			break;
531 		case 1:
532 			yres = (xres * 3)/4;
533 			break;
534 		case 2:
535 			yres = (xres * 4)/5;
536 			break;
537 		case 3:
538 			yres = (xres * 9)/16;
539 			break;
540 		}
541 		refresh = (block[1] & 0x3f) + 60;
542 		DPRINTK("      %dx%d@%dHz\n", xres, yres, refresh);
543 
544 		calc_mode_timings(xres, yres, refresh, mode);
545 	}
546 
547 	/* Check the mode we got is within valid spec of the monitor */
548 	if (specs && specs->dclkmax
549 	    && PICOS2KHZ(mode->pixclock) * 1000 > specs->dclkmax) {
550 		DPRINTK("        mode exceed max DCLK\n");
551 		return 0;
552 	}
553 
554 	return 1;
555 }
556 
557 static int get_dst_timing(unsigned char *block, struct fb_videomode *mode,
558 			  int ver, int rev, const struct fb_monspecs *specs)
559 {
560 	int j, num = 0;
561 
562 	for (j = 0; j < 6; j++, block += STD_TIMING_DESCRIPTION_SIZE)
563 		num += get_std_timing(block, &mode[num], ver, rev, specs);
564 
565 	return num;
566 }
567 
568 static void get_detailed_timing(unsigned char *block,
569 				struct fb_videomode *mode)
570 {
571 	mode->xres = H_ACTIVE;
572 	mode->yres = V_ACTIVE;
573 	mode->pixclock = PIXEL_CLOCK;
574 	mode->pixclock /= 1000;
575 	mode->pixclock = KHZ2PICOS(mode->pixclock);
576 	mode->right_margin = H_SYNC_OFFSET;
577 	mode->left_margin = (H_ACTIVE + H_BLANKING) -
578 		(H_ACTIVE + H_SYNC_OFFSET + H_SYNC_WIDTH);
579 	mode->upper_margin = V_BLANKING - V_SYNC_OFFSET -
580 		V_SYNC_WIDTH;
581 	mode->lower_margin = V_SYNC_OFFSET;
582 	mode->hsync_len = H_SYNC_WIDTH;
583 	mode->vsync_len = V_SYNC_WIDTH;
584 	if (HSYNC_POSITIVE)
585 		mode->sync |= FB_SYNC_HOR_HIGH_ACT;
586 	if (VSYNC_POSITIVE)
587 		mode->sync |= FB_SYNC_VERT_HIGH_ACT;
588 	mode->refresh = PIXEL_CLOCK/((H_ACTIVE + H_BLANKING) *
589 				     (V_ACTIVE + V_BLANKING));
590 	if (INTERLACED) {
591 		mode->yres *= 2;
592 		mode->upper_margin *= 2;
593 		mode->lower_margin *= 2;
594 		mode->vsync_len *= 2;
595 		mode->vmode |= FB_VMODE_INTERLACED;
596 	}
597 	mode->flag = FB_MODE_IS_DETAILED;
598 
599 	DPRINTK("      %d MHz ",  PIXEL_CLOCK/1000000);
600 	DPRINTK("%d %d %d %d ", H_ACTIVE, H_ACTIVE + H_SYNC_OFFSET,
601 	       H_ACTIVE + H_SYNC_OFFSET + H_SYNC_WIDTH, H_ACTIVE + H_BLANKING);
602 	DPRINTK("%d %d %d %d ", V_ACTIVE, V_ACTIVE + V_SYNC_OFFSET,
603 	       V_ACTIVE + V_SYNC_OFFSET + V_SYNC_WIDTH, V_ACTIVE + V_BLANKING);
604 	DPRINTK("%sHSync %sVSync\n\n", (HSYNC_POSITIVE) ? "+" : "-",
605 	       (VSYNC_POSITIVE) ? "+" : "-");
606 }
607 
608 /**
609  * fb_create_modedb - create video mode database
610  * @edid: EDID data
611  * @dbsize: database size
612  *
613  * RETURNS: struct fb_videomode, @dbsize contains length of database
614  *
615  * DESCRIPTION:
616  * This function builds a mode database using the contents of the EDID
617  * data
618  */
619 static struct fb_videomode *fb_create_modedb(unsigned char *edid, int *dbsize,
620 					     const struct fb_monspecs *specs)
621 {
622 	struct fb_videomode *mode, *m;
623 	unsigned char *block;
624 	int num = 0, i, first = 1;
625 	int ver, rev;
626 
627 	mode = kzalloc(50 * sizeof(struct fb_videomode), GFP_KERNEL);
628 	if (mode == NULL)
629 		return NULL;
630 
631 	if (edid == NULL || !edid_checksum(edid) ||
632 	    !edid_check_header(edid)) {
633 		kfree(mode);
634 		return NULL;
635 	}
636 
637 	ver = edid[EDID_STRUCT_VERSION];
638 	rev = edid[EDID_STRUCT_REVISION];
639 
640 	*dbsize = 0;
641 
642 	DPRINTK("   Detailed Timings\n");
643 	block = edid + DETAILED_TIMING_DESCRIPTIONS_START;
644 	for (i = 0; i < 4; i++, block+= DETAILED_TIMING_DESCRIPTION_SIZE) {
645 		if (!(block[0] == 0x00 && block[1] == 0x00)) {
646 			get_detailed_timing(block, &mode[num]);
647 			if (first) {
648 			        mode[num].flag |= FB_MODE_IS_FIRST;
649 				first = 0;
650 			}
651 			num++;
652 		}
653 	}
654 
655 	DPRINTK("   Supported VESA Modes\n");
656 	block = edid + ESTABLISHED_TIMING_1;
657 	num += get_est_timing(block, &mode[num]);
658 
659 	DPRINTK("   Standard Timings\n");
660 	block = edid + STD_TIMING_DESCRIPTIONS_START;
661 	for (i = 0; i < STD_TIMING; i++, block += STD_TIMING_DESCRIPTION_SIZE)
662 		num += get_std_timing(block, &mode[num], ver, rev, specs);
663 
664 	block = edid + DETAILED_TIMING_DESCRIPTIONS_START;
665 	for (i = 0; i < 4; i++, block+= DETAILED_TIMING_DESCRIPTION_SIZE) {
666 		if (block[0] == 0x00 && block[1] == 0x00 && block[3] == 0xfa)
667 			num += get_dst_timing(block + 5, &mode[num],
668 					      ver, rev, specs);
669 	}
670 
671 	/* Yikes, EDID data is totally useless */
672 	if (!num) {
673 		kfree(mode);
674 		return NULL;
675 	}
676 
677 	*dbsize = num;
678 	m = kmalloc(num * sizeof(struct fb_videomode), GFP_KERNEL);
679 	if (!m)
680 		return mode;
681 	memmove(m, mode, num * sizeof(struct fb_videomode));
682 	kfree(mode);
683 	return m;
684 }
685 
686 /**
687  * fb_destroy_modedb - destroys mode database
688  * @modedb: mode database to destroy
689  *
690  * DESCRIPTION:
691  * Destroy mode database created by fb_create_modedb
692  */
693 void fb_destroy_modedb(struct fb_videomode *modedb)
694 {
695 	kfree(modedb);
696 }
697 
698 static int fb_get_monitor_limits(unsigned char *edid, struct fb_monspecs *specs)
699 {
700 	int i, retval = 1;
701 	unsigned char *block;
702 
703 	block = edid + DETAILED_TIMING_DESCRIPTIONS_START;
704 
705 	DPRINTK("      Monitor Operating Limits: ");
706 
707 	for (i = 0; i < 4; i++, block += DETAILED_TIMING_DESCRIPTION_SIZE) {
708 		if (edid_is_limits_block(block)) {
709 			specs->hfmin = H_MIN_RATE * 1000;
710 			specs->hfmax = H_MAX_RATE * 1000;
711 			specs->vfmin = V_MIN_RATE;
712 			specs->vfmax = V_MAX_RATE;
713 			specs->dclkmax = MAX_PIXEL_CLOCK * 1000000;
714 			specs->gtf = (GTF_SUPPORT) ? 1 : 0;
715 			retval = 0;
716 			DPRINTK("From EDID\n");
717 			break;
718 		}
719 	}
720 
721 	/* estimate monitor limits based on modes supported */
722 	if (retval) {
723 		struct fb_videomode *modes, *mode;
724 		int num_modes, hz, hscan, pixclock;
725 		int vtotal, htotal;
726 
727 		modes = fb_create_modedb(edid, &num_modes, specs);
728 		if (!modes) {
729 			DPRINTK("None Available\n");
730 			return 1;
731 		}
732 
733 		retval = 0;
734 		for (i = 0; i < num_modes; i++) {
735 			mode = &modes[i];
736 			pixclock = PICOS2KHZ(modes[i].pixclock) * 1000;
737 			htotal = mode->xres + mode->right_margin + mode->hsync_len
738 				+ mode->left_margin;
739 			vtotal = mode->yres + mode->lower_margin + mode->vsync_len
740 				+ mode->upper_margin;
741 
742 			if (mode->vmode & FB_VMODE_INTERLACED)
743 				vtotal /= 2;
744 
745 			if (mode->vmode & FB_VMODE_DOUBLE)
746 				vtotal *= 2;
747 
748 			hscan = (pixclock + htotal / 2) / htotal;
749 			hscan = (hscan + 500) / 1000 * 1000;
750 			hz = (hscan + vtotal / 2) / vtotal;
751 
752 			if (specs->dclkmax == 0 || specs->dclkmax < pixclock)
753 				specs->dclkmax = pixclock;
754 
755 			if (specs->dclkmin == 0 || specs->dclkmin > pixclock)
756 				specs->dclkmin = pixclock;
757 
758 			if (specs->hfmax == 0 || specs->hfmax < hscan)
759 				specs->hfmax = hscan;
760 
761 			if (specs->hfmin == 0 || specs->hfmin > hscan)
762 				specs->hfmin = hscan;
763 
764 			if (specs->vfmax == 0 || specs->vfmax < hz)
765 				specs->vfmax = hz;
766 
767 			if (specs->vfmin == 0 || specs->vfmin > hz)
768 				specs->vfmin = hz;
769 		}
770 		DPRINTK("Extrapolated\n");
771 		fb_destroy_modedb(modes);
772 	}
773 	DPRINTK("           H: %d-%dKHz V: %d-%dHz DCLK: %dMHz\n",
774 		specs->hfmin/1000, specs->hfmax/1000, specs->vfmin,
775 		specs->vfmax, specs->dclkmax/1000000);
776 	return retval;
777 }
778 
779 static void get_monspecs(unsigned char *edid, struct fb_monspecs *specs)
780 {
781 	unsigned char c, *block;
782 
783 	block = edid + EDID_STRUCT_DISPLAY;
784 
785 	fb_get_monitor_limits(edid, specs);
786 
787 	c = block[0] & 0x80;
788 	specs->input = 0;
789 	if (c) {
790 		specs->input |= FB_DISP_DDI;
791 		DPRINTK("      Digital Display Input");
792 	} else {
793 		DPRINTK("      Analog Display Input: Input Voltage - ");
794 		switch ((block[0] & 0x60) >> 5) {
795 		case 0:
796 			DPRINTK("0.700V/0.300V");
797 			specs->input |= FB_DISP_ANA_700_300;
798 			break;
799 		case 1:
800 			DPRINTK("0.714V/0.286V");
801 			specs->input |= FB_DISP_ANA_714_286;
802 			break;
803 		case 2:
804 			DPRINTK("1.000V/0.400V");
805 			specs->input |= FB_DISP_ANA_1000_400;
806 			break;
807 		case 3:
808 			DPRINTK("0.700V/0.000V");
809 			specs->input |= FB_DISP_ANA_700_000;
810 			break;
811 		}
812 	}
813 	DPRINTK("\n      Sync: ");
814 	c = block[0] & 0x10;
815 	if (c)
816 		DPRINTK("      Configurable signal level\n");
817 	c = block[0] & 0x0f;
818 	specs->signal = 0;
819 	if (c & 0x10) {
820 		DPRINTK("Blank to Blank ");
821 		specs->signal |= FB_SIGNAL_BLANK_BLANK;
822 	}
823 	if (c & 0x08) {
824 		DPRINTK("Separate ");
825 		specs->signal |= FB_SIGNAL_SEPARATE;
826 	}
827 	if (c & 0x04) {
828 		DPRINTK("Composite ");
829 		specs->signal |= FB_SIGNAL_COMPOSITE;
830 	}
831 	if (c & 0x02) {
832 		DPRINTK("Sync on Green ");
833 		specs->signal |= FB_SIGNAL_SYNC_ON_GREEN;
834 	}
835 	if (c & 0x01) {
836 		DPRINTK("Serration on ");
837 		specs->signal |= FB_SIGNAL_SERRATION_ON;
838 	}
839 	DPRINTK("\n");
840 	specs->max_x = block[1];
841 	specs->max_y = block[2];
842 	DPRINTK("      Max H-size in cm: ");
843 	if (specs->max_x)
844 		DPRINTK("%d\n", specs->max_x);
845 	else
846 		DPRINTK("variable\n");
847 	DPRINTK("      Max V-size in cm: ");
848 	if (specs->max_y)
849 		DPRINTK("%d\n", specs->max_y);
850 	else
851 		DPRINTK("variable\n");
852 
853 	c = block[3];
854 	specs->gamma = c+100;
855 	DPRINTK("      Gamma: ");
856 	DPRINTK("%d.%d\n", specs->gamma/100, specs->gamma % 100);
857 
858 	get_dpms_capabilities(block[4], specs);
859 
860 	switch ((block[4] & 0x18) >> 3) {
861 	case 0:
862 		DPRINTK("      Monochrome/Grayscale\n");
863 		specs->input |= FB_DISP_MONO;
864 		break;
865 	case 1:
866 		DPRINTK("      RGB Color Display\n");
867 		specs->input |= FB_DISP_RGB;
868 		break;
869 	case 2:
870 		DPRINTK("      Non-RGB Multicolor Display\n");
871 		specs->input |= FB_DISP_MULTI;
872 		break;
873 	default:
874 		DPRINTK("      Unknown\n");
875 		specs->input |= FB_DISP_UNKNOWN;
876 		break;
877 	}
878 
879 	get_chroma(block, specs);
880 
881 	specs->misc = 0;
882 	c = block[4] & 0x7;
883 	if (c & 0x04) {
884 		DPRINTK("      Default color format is primary\n");
885 		specs->misc |= FB_MISC_PRIM_COLOR;
886 	}
887 	if (c & 0x02) {
888 		DPRINTK("      First DETAILED Timing is preferred\n");
889 		specs->misc |= FB_MISC_1ST_DETAIL;
890 	}
891 	if (c & 0x01) {
892 		printk("      Display is GTF capable\n");
893 		specs->gtf = 1;
894 	}
895 }
896 
897 int fb_parse_edid(unsigned char *edid, struct fb_var_screeninfo *var)
898 {
899 	int i;
900 	unsigned char *block;
901 
902 	if (edid == NULL || var == NULL)
903 		return 1;
904 
905 	if (!(edid_checksum(edid)))
906 		return 1;
907 
908 	if (!(edid_check_header(edid)))
909 		return 1;
910 
911 	block = edid + DETAILED_TIMING_DESCRIPTIONS_START;
912 
913 	for (i = 0; i < 4; i++, block += DETAILED_TIMING_DESCRIPTION_SIZE) {
914 		if (edid_is_timing_block(block)) {
915 			var->xres = var->xres_virtual = H_ACTIVE;
916 			var->yres = var->yres_virtual = V_ACTIVE;
917 			var->height = var->width = 0;
918 			var->right_margin = H_SYNC_OFFSET;
919 			var->left_margin = (H_ACTIVE + H_BLANKING) -
920 				(H_ACTIVE + H_SYNC_OFFSET + H_SYNC_WIDTH);
921 			var->upper_margin = V_BLANKING - V_SYNC_OFFSET -
922 				V_SYNC_WIDTH;
923 			var->lower_margin = V_SYNC_OFFSET;
924 			var->hsync_len = H_SYNC_WIDTH;
925 			var->vsync_len = V_SYNC_WIDTH;
926 			var->pixclock = PIXEL_CLOCK;
927 			var->pixclock /= 1000;
928 			var->pixclock = KHZ2PICOS(var->pixclock);
929 
930 			if (HSYNC_POSITIVE)
931 				var->sync |= FB_SYNC_HOR_HIGH_ACT;
932 			if (VSYNC_POSITIVE)
933 				var->sync |= FB_SYNC_VERT_HIGH_ACT;
934 			return 0;
935 		}
936 	}
937 	return 1;
938 }
939 
940 void fb_edid_to_monspecs(unsigned char *edid, struct fb_monspecs *specs)
941 {
942 	unsigned char *block;
943 	int i, found = 0;
944 
945 	if (edid == NULL)
946 		return;
947 
948 	if (!(edid_checksum(edid)))
949 		return;
950 
951 	if (!(edid_check_header(edid)))
952 		return;
953 
954 	memset(specs, 0, sizeof(struct fb_monspecs));
955 
956 	specs->version = edid[EDID_STRUCT_VERSION];
957 	specs->revision = edid[EDID_STRUCT_REVISION];
958 
959 	DPRINTK("========================================\n");
960 	DPRINTK("Display Information (EDID)\n");
961 	DPRINTK("========================================\n");
962 	DPRINTK("   EDID Version %d.%d\n", (int) specs->version,
963 	       (int) specs->revision);
964 
965 	parse_vendor_block(edid + ID_MANUFACTURER_NAME, specs);
966 
967 	block = edid + DETAILED_TIMING_DESCRIPTIONS_START;
968 	for (i = 0; i < 4; i++, block += DETAILED_TIMING_DESCRIPTION_SIZE) {
969 		if (edid_is_serial_block(block)) {
970 			copy_string(block, specs->serial_no);
971 			DPRINTK("   Serial Number: %s\n", specs->serial_no);
972 		} else if (edid_is_ascii_block(block)) {
973 			copy_string(block, specs->ascii);
974 			DPRINTK("   ASCII Block: %s\n", specs->ascii);
975 		} else if (edid_is_monitor_block(block)) {
976 			copy_string(block, specs->monitor);
977 			DPRINTK("   Monitor Name: %s\n", specs->monitor);
978 		}
979 	}
980 
981 	DPRINTK("   Display Characteristics:\n");
982 	get_monspecs(edid, specs);
983 
984 	specs->modedb = fb_create_modedb(edid, &specs->modedb_len, specs);
985 
986 	/*
987 	 * Workaround for buggy EDIDs that sets that the first
988 	 * detailed timing is preferred but has not detailed
989 	 * timing specified
990 	 */
991 	for (i = 0; i < specs->modedb_len; i++) {
992 		if (specs->modedb[i].flag & FB_MODE_IS_DETAILED) {
993 			found = 1;
994 			break;
995 		}
996 	}
997 
998 	if (!found)
999 		specs->misc &= ~FB_MISC_1ST_DETAIL;
1000 
1001 	DPRINTK("========================================\n");
1002 }
1003 
1004 /**
1005  * fb_edid_add_monspecs() - add monitor video modes from E-EDID data
1006  * @edid:	128 byte array with an E-EDID block
1007  * @spacs:	monitor specs to be extended
1008  */
1009 void fb_edid_add_monspecs(unsigned char *edid, struct fb_monspecs *specs)
1010 {
1011 	unsigned char *block;
1012 	struct fb_videomode *m;
1013 	int num = 0, i;
1014 	u8 svd[64], edt[(128 - 4) / DETAILED_TIMING_DESCRIPTION_SIZE];
1015 	u8 pos = 4, svd_n = 0;
1016 
1017 	if (!edid)
1018 		return;
1019 
1020 	if (!edid_checksum(edid))
1021 		return;
1022 
1023 	if (edid[0] != 0x2 ||
1024 	    edid[2] < 4 || edid[2] > 128 - DETAILED_TIMING_DESCRIPTION_SIZE)
1025 		return;
1026 
1027 	DPRINTK("  Short Video Descriptors\n");
1028 
1029 	while (pos < edid[2]) {
1030 		u8 len = edid[pos] & 0x1f, type = (edid[pos] >> 5) & 7;
1031 		pr_debug("Data block %u of %u bytes\n", type, len);
1032 		if (type == 2) {
1033 			for (i = pos; i < pos + len; i++) {
1034 				u8 idx = edid[pos + i] & 0x7f;
1035 				svd[svd_n++] = idx;
1036 				pr_debug("N%sative mode #%d\n",
1037 					 edid[pos + i] & 0x80 ? "" : "on-n", idx);
1038 			}
1039 		} else if (type == 3 && len >= 3) {
1040 			/* Check Vendor Specific Data Block.  For HDMI,
1041 			   it is always 00-0C-03 for HDMI Licensing, LLC. */
1042 			if (edid[pos + 1] == 3 && edid[pos + 2] == 0xc &&
1043 			    edid[pos + 3] == 0)
1044 				specs->misc |= FB_MISC_HDMI;
1045 		}
1046 		pos += len + 1;
1047 	}
1048 
1049 	block = edid + edid[2];
1050 
1051 	DPRINTK("  Extended Detailed Timings\n");
1052 
1053 	for (i = 0; i < (128 - edid[2]) / DETAILED_TIMING_DESCRIPTION_SIZE;
1054 	     i++, block += DETAILED_TIMING_DESCRIPTION_SIZE)
1055 		if (PIXEL_CLOCK)
1056 			edt[num++] = block - edid;
1057 
1058 	/* Yikes, EDID data is totally useless */
1059 	if (!(num + svd_n))
1060 		return;
1061 
1062 	m = kzalloc((specs->modedb_len + num + svd_n) *
1063 		       sizeof(struct fb_videomode), GFP_KERNEL);
1064 
1065 	if (!m)
1066 		return;
1067 
1068 	memcpy(m, specs->modedb, specs->modedb_len * sizeof(struct fb_videomode));
1069 
1070 	for (i = specs->modedb_len; i < specs->modedb_len + num; i++) {
1071 		get_detailed_timing(edid + edt[i - specs->modedb_len], &m[i]);
1072 		if (i == specs->modedb_len)
1073 			m[i].flag |= FB_MODE_IS_FIRST;
1074 		pr_debug("Adding %ux%u@%u\n", m[i].xres, m[i].yres, m[i].refresh);
1075 	}
1076 
1077 	for (i = specs->modedb_len + num; i < specs->modedb_len + num + svd_n; i++) {
1078 		int idx = svd[i - specs->modedb_len - num];
1079 		if (!idx || idx > 63) {
1080 			pr_warning("Reserved SVD code %d\n", idx);
1081 		} else if (idx > ARRAY_SIZE(cea_modes) || !cea_modes[idx].xres) {
1082 			pr_warning("Unimplemented SVD code %d\n", idx);
1083 		} else {
1084 			memcpy(&m[i], cea_modes + idx, sizeof(m[i]));
1085 			pr_debug("Adding SVD #%d: %ux%u@%u\n", idx,
1086 				 m[i].xres, m[i].yres, m[i].refresh);
1087 		}
1088 	}
1089 
1090 	kfree(specs->modedb);
1091 	specs->modedb = m;
1092 	specs->modedb_len = specs->modedb_len + num + svd_n;
1093 }
1094 
1095 /*
1096  * VESA Generalized Timing Formula (GTF)
1097  */
1098 
1099 #define FLYBACK                     550
1100 #define V_FRONTPORCH                1
1101 #define H_OFFSET                    40
1102 #define H_SCALEFACTOR               20
1103 #define H_BLANKSCALE                128
1104 #define H_GRADIENT                  600
1105 #define C_VAL                       30
1106 #define M_VAL                       300
1107 
1108 struct __fb_timings {
1109 	u32 dclk;
1110 	u32 hfreq;
1111 	u32 vfreq;
1112 	u32 hactive;
1113 	u32 vactive;
1114 	u32 hblank;
1115 	u32 vblank;
1116 	u32 htotal;
1117 	u32 vtotal;
1118 };
1119 
1120 /**
1121  * fb_get_vblank - get vertical blank time
1122  * @hfreq: horizontal freq
1123  *
1124  * DESCRIPTION:
1125  * vblank = right_margin + vsync_len + left_margin
1126  *
1127  *    given: right_margin = 1 (V_FRONTPORCH)
1128  *           vsync_len    = 3
1129  *           flyback      = 550
1130  *
1131  *                          flyback * hfreq
1132  *           left_margin  = --------------- - vsync_len
1133  *                           1000000
1134  */
1135 static u32 fb_get_vblank(u32 hfreq)
1136 {
1137 	u32 vblank;
1138 
1139 	vblank = (hfreq * FLYBACK)/1000;
1140 	vblank = (vblank + 500)/1000;
1141 	return (vblank + V_FRONTPORCH);
1142 }
1143 
1144 /**
1145  * fb_get_hblank_by_freq - get horizontal blank time given hfreq
1146  * @hfreq: horizontal freq
1147  * @xres: horizontal resolution in pixels
1148  *
1149  * DESCRIPTION:
1150  *
1151  *           xres * duty_cycle
1152  * hblank = ------------------
1153  *           100 - duty_cycle
1154  *
1155  * duty cycle = percent of htotal assigned to inactive display
1156  * duty cycle = C - (M/Hfreq)
1157  *
1158  * where: C = ((offset - scale factor) * blank_scale)
1159  *            -------------------------------------- + scale factor
1160  *                        256
1161  *        M = blank_scale * gradient
1162  *
1163  */
1164 static u32 fb_get_hblank_by_hfreq(u32 hfreq, u32 xres)
1165 {
1166 	u32 c_val, m_val, duty_cycle, hblank;
1167 
1168 	c_val = (((H_OFFSET - H_SCALEFACTOR) * H_BLANKSCALE)/256 +
1169 		 H_SCALEFACTOR) * 1000;
1170 	m_val = (H_BLANKSCALE * H_GRADIENT)/256;
1171 	m_val = (m_val * 1000000)/hfreq;
1172 	duty_cycle = c_val - m_val;
1173 	hblank = (xres * duty_cycle)/(100000 - duty_cycle);
1174 	return (hblank);
1175 }
1176 
1177 /**
1178  * fb_get_hblank_by_dclk - get horizontal blank time given pixelclock
1179  * @dclk: pixelclock in Hz
1180  * @xres: horizontal resolution in pixels
1181  *
1182  * DESCRIPTION:
1183  *
1184  *           xres * duty_cycle
1185  * hblank = ------------------
1186  *           100 - duty_cycle
1187  *
1188  * duty cycle = percent of htotal assigned to inactive display
1189  * duty cycle = C - (M * h_period)
1190  *
1191  * where: h_period = SQRT(100 - C + (0.4 * xres * M)/dclk) + C - 100
1192  *                   -----------------------------------------------
1193  *                                    2 * M
1194  *        M = 300;
1195  *        C = 30;
1196 
1197  */
1198 static u32 fb_get_hblank_by_dclk(u32 dclk, u32 xres)
1199 {
1200 	u32 duty_cycle, h_period, hblank;
1201 
1202 	dclk /= 1000;
1203 	h_period = 100 - C_VAL;
1204 	h_period *= h_period;
1205 	h_period += (M_VAL * xres * 2 * 1000)/(5 * dclk);
1206 	h_period *= 10000;
1207 
1208 	h_period = int_sqrt(h_period);
1209 	h_period -= (100 - C_VAL) * 100;
1210 	h_period *= 1000;
1211 	h_period /= 2 * M_VAL;
1212 
1213 	duty_cycle = C_VAL * 1000 - (M_VAL * h_period)/100;
1214 	hblank = (xres * duty_cycle)/(100000 - duty_cycle) + 8;
1215 	hblank &= ~15;
1216 	return (hblank);
1217 }
1218 
1219 /**
1220  * fb_get_hfreq - estimate hsync
1221  * @vfreq: vertical refresh rate
1222  * @yres: vertical resolution
1223  *
1224  * DESCRIPTION:
1225  *
1226  *          (yres + front_port) * vfreq * 1000000
1227  * hfreq = -------------------------------------
1228  *          (1000000 - (vfreq * FLYBACK)
1229  *
1230  */
1231 
1232 static u32 fb_get_hfreq(u32 vfreq, u32 yres)
1233 {
1234 	u32 divisor, hfreq;
1235 
1236 	divisor = (1000000 - (vfreq * FLYBACK))/1000;
1237 	hfreq = (yres + V_FRONTPORCH) * vfreq  * 1000;
1238 	return (hfreq/divisor);
1239 }
1240 
1241 static void fb_timings_vfreq(struct __fb_timings *timings)
1242 {
1243 	timings->hfreq = fb_get_hfreq(timings->vfreq, timings->vactive);
1244 	timings->vblank = fb_get_vblank(timings->hfreq);
1245 	timings->vtotal = timings->vactive + timings->vblank;
1246 	timings->hblank = fb_get_hblank_by_hfreq(timings->hfreq,
1247 						 timings->hactive);
1248 	timings->htotal = timings->hactive + timings->hblank;
1249 	timings->dclk = timings->htotal * timings->hfreq;
1250 }
1251 
1252 static void fb_timings_hfreq(struct __fb_timings *timings)
1253 {
1254 	timings->vblank = fb_get_vblank(timings->hfreq);
1255 	timings->vtotal = timings->vactive + timings->vblank;
1256 	timings->vfreq = timings->hfreq/timings->vtotal;
1257 	timings->hblank = fb_get_hblank_by_hfreq(timings->hfreq,
1258 						 timings->hactive);
1259 	timings->htotal = timings->hactive + timings->hblank;
1260 	timings->dclk = timings->htotal * timings->hfreq;
1261 }
1262 
1263 static void fb_timings_dclk(struct __fb_timings *timings)
1264 {
1265 	timings->hblank = fb_get_hblank_by_dclk(timings->dclk,
1266 						timings->hactive);
1267 	timings->htotal = timings->hactive + timings->hblank;
1268 	timings->hfreq = timings->dclk/timings->htotal;
1269 	timings->vblank = fb_get_vblank(timings->hfreq);
1270 	timings->vtotal = timings->vactive + timings->vblank;
1271 	timings->vfreq = timings->hfreq/timings->vtotal;
1272 }
1273 
1274 /*
1275  * fb_get_mode - calculates video mode using VESA GTF
1276  * @flags: if: 0 - maximize vertical refresh rate
1277  *             1 - vrefresh-driven calculation;
1278  *             2 - hscan-driven calculation;
1279  *             3 - pixelclock-driven calculation;
1280  * @val: depending on @flags, ignored, vrefresh, hsync or pixelclock
1281  * @var: pointer to fb_var_screeninfo
1282  * @info: pointer to fb_info
1283  *
1284  * DESCRIPTION:
1285  * Calculates video mode based on monitor specs using VESA GTF.
1286  * The GTF is best for VESA GTF compliant monitors but is
1287  * specifically formulated to work for older monitors as well.
1288  *
1289  * If @flag==0, the function will attempt to maximize the
1290  * refresh rate.  Otherwise, it will calculate timings based on
1291  * the flag and accompanying value.
1292  *
1293  * If FB_IGNOREMON bit is set in @flags, monitor specs will be
1294  * ignored and @var will be filled with the calculated timings.
1295  *
1296  * All calculations are based on the VESA GTF Spreadsheet
1297  * available at VESA's public ftp (http://www.vesa.org).
1298  *
1299  * NOTES:
1300  * The timings generated by the GTF will be different from VESA
1301  * DMT.  It might be a good idea to keep a table of standard
1302  * VESA modes as well.  The GTF may also not work for some displays,
1303  * such as, and especially, analog TV.
1304  *
1305  * REQUIRES:
1306  * A valid info->monspecs, otherwise 'safe numbers' will be used.
1307  */
1308 int fb_get_mode(int flags, u32 val, struct fb_var_screeninfo *var, struct fb_info *info)
1309 {
1310 	struct __fb_timings *timings;
1311 	u32 interlace = 1, dscan = 1;
1312 	u32 hfmin, hfmax, vfmin, vfmax, dclkmin, dclkmax, err = 0;
1313 
1314 
1315 	timings = kzalloc(sizeof(struct __fb_timings), GFP_KERNEL);
1316 
1317 	if (!timings)
1318 		return -ENOMEM;
1319 
1320 	/*
1321 	 * If monspecs are invalid, use values that are enough
1322 	 * for 640x480@60
1323 	 */
1324 	if (!info || !info->monspecs.hfmax || !info->monspecs.vfmax ||
1325 	    !info->monspecs.dclkmax ||
1326 	    info->monspecs.hfmax < info->monspecs.hfmin ||
1327 	    info->monspecs.vfmax < info->monspecs.vfmin ||
1328 	    info->monspecs.dclkmax < info->monspecs.dclkmin) {
1329 		hfmin = 29000; hfmax = 30000;
1330 		vfmin = 60; vfmax = 60;
1331 		dclkmin = 0; dclkmax = 25000000;
1332 	} else {
1333 		hfmin = info->monspecs.hfmin;
1334 		hfmax = info->monspecs.hfmax;
1335 		vfmin = info->monspecs.vfmin;
1336 		vfmax = info->monspecs.vfmax;
1337 		dclkmin = info->monspecs.dclkmin;
1338 		dclkmax = info->monspecs.dclkmax;
1339 	}
1340 
1341 	timings->hactive = var->xres;
1342 	timings->vactive = var->yres;
1343 	if (var->vmode & FB_VMODE_INTERLACED) {
1344 		timings->vactive /= 2;
1345 		interlace = 2;
1346 	}
1347 	if (var->vmode & FB_VMODE_DOUBLE) {
1348 		timings->vactive *= 2;
1349 		dscan = 2;
1350 	}
1351 
1352 	switch (flags & ~FB_IGNOREMON) {
1353 	case FB_MAXTIMINGS: /* maximize refresh rate */
1354 		timings->hfreq = hfmax;
1355 		fb_timings_hfreq(timings);
1356 		if (timings->vfreq > vfmax) {
1357 			timings->vfreq = vfmax;
1358 			fb_timings_vfreq(timings);
1359 		}
1360 		if (timings->dclk > dclkmax) {
1361 			timings->dclk = dclkmax;
1362 			fb_timings_dclk(timings);
1363 		}
1364 		break;
1365 	case FB_VSYNCTIMINGS: /* vrefresh driven */
1366 		timings->vfreq = val;
1367 		fb_timings_vfreq(timings);
1368 		break;
1369 	case FB_HSYNCTIMINGS: /* hsync driven */
1370 		timings->hfreq = val;
1371 		fb_timings_hfreq(timings);
1372 		break;
1373 	case FB_DCLKTIMINGS: /* pixelclock driven */
1374 		timings->dclk = PICOS2KHZ(val) * 1000;
1375 		fb_timings_dclk(timings);
1376 		break;
1377 	default:
1378 		err = -EINVAL;
1379 
1380 	}
1381 
1382 	if (err || (!(flags & FB_IGNOREMON) &&
1383 	    (timings->vfreq < vfmin || timings->vfreq > vfmax ||
1384 	     timings->hfreq < hfmin || timings->hfreq > hfmax ||
1385 	     timings->dclk < dclkmin || timings->dclk > dclkmax))) {
1386 		err = -EINVAL;
1387 	} else {
1388 		var->pixclock = KHZ2PICOS(timings->dclk/1000);
1389 		var->hsync_len = (timings->htotal * 8)/100;
1390 		var->right_margin = (timings->hblank/2) - var->hsync_len;
1391 		var->left_margin = timings->hblank - var->right_margin -
1392 			var->hsync_len;
1393 		var->vsync_len = (3 * interlace)/dscan;
1394 		var->lower_margin = (1 * interlace)/dscan;
1395 		var->upper_margin = (timings->vblank * interlace)/dscan -
1396 			(var->vsync_len + var->lower_margin);
1397 	}
1398 
1399 	kfree(timings);
1400 	return err;
1401 }
1402 
1403 #ifdef CONFIG_VIDEOMODE_HELPERS
1404 int fb_videomode_from_videomode(const struct videomode *vm,
1405 				struct fb_videomode *fbmode)
1406 {
1407 	unsigned int htotal, vtotal;
1408 
1409 	fbmode->xres = vm->hactive;
1410 	fbmode->left_margin = vm->hback_porch;
1411 	fbmode->right_margin = vm->hfront_porch;
1412 	fbmode->hsync_len = vm->hsync_len;
1413 
1414 	fbmode->yres = vm->vactive;
1415 	fbmode->upper_margin = vm->vback_porch;
1416 	fbmode->lower_margin = vm->vfront_porch;
1417 	fbmode->vsync_len = vm->vsync_len;
1418 
1419 	/* prevent division by zero in KHZ2PICOS macro */
1420 	fbmode->pixclock = vm->pixelclock ?
1421 			KHZ2PICOS(vm->pixelclock / 1000) : 0;
1422 
1423 	fbmode->sync = 0;
1424 	fbmode->vmode = 0;
1425 	if (vm->flags & DISPLAY_FLAGS_HSYNC_HIGH)
1426 		fbmode->sync |= FB_SYNC_HOR_HIGH_ACT;
1427 	if (vm->flags & DISPLAY_FLAGS_VSYNC_HIGH)
1428 		fbmode->sync |= FB_SYNC_VERT_HIGH_ACT;
1429 	if (vm->flags & DISPLAY_FLAGS_INTERLACED)
1430 		fbmode->vmode |= FB_VMODE_INTERLACED;
1431 	if (vm->flags & DISPLAY_FLAGS_DOUBLESCAN)
1432 		fbmode->vmode |= FB_VMODE_DOUBLE;
1433 	fbmode->flag = 0;
1434 
1435 	htotal = vm->hactive + vm->hfront_porch + vm->hback_porch +
1436 		 vm->hsync_len;
1437 	vtotal = vm->vactive + vm->vfront_porch + vm->vback_porch +
1438 		 vm->vsync_len;
1439 	/* prevent division by zero */
1440 	if (htotal && vtotal) {
1441 		fbmode->refresh = vm->pixelclock / (htotal * vtotal);
1442 	/* a mode must have htotal and vtotal != 0 or it is invalid */
1443 	} else {
1444 		fbmode->refresh = 0;
1445 		return -EINVAL;
1446 	}
1447 
1448 	return 0;
1449 }
1450 EXPORT_SYMBOL_GPL(fb_videomode_from_videomode);
1451 
1452 #ifdef CONFIG_OF
1453 static inline void dump_fb_videomode(const struct fb_videomode *m)
1454 {
1455 	pr_debug("fb_videomode = %ux%u@%uHz (%ukHz) %u %u %u %u %u %u %u %u %u\n",
1456 		 m->xres, m->yres, m->refresh, m->pixclock, m->left_margin,
1457 		 m->right_margin, m->upper_margin, m->lower_margin,
1458 		 m->hsync_len, m->vsync_len, m->sync, m->vmode, m->flag);
1459 }
1460 
1461 /**
1462  * of_get_fb_videomode - get a fb_videomode from devicetree
1463  * @np: device_node with the timing specification
1464  * @fb: will be set to the return value
1465  * @index: index into the list of display timings in devicetree
1466  *
1467  * DESCRIPTION:
1468  * This function is expensive and should only be used, if only one mode is to be
1469  * read from DT. To get multiple modes start with of_get_display_timings ond
1470  * work with that instead.
1471  */
1472 int of_get_fb_videomode(struct device_node *np, struct fb_videomode *fb,
1473 			int index)
1474 {
1475 	struct videomode vm;
1476 	int ret;
1477 
1478 	ret = of_get_videomode(np, &vm, index);
1479 	if (ret)
1480 		return ret;
1481 
1482 	fb_videomode_from_videomode(&vm, fb);
1483 
1484 	pr_debug("%s: got %dx%d display mode from %s\n",
1485 		of_node_full_name(np), vm.hactive, vm.vactive, np->name);
1486 	dump_fb_videomode(fb);
1487 
1488 	return 0;
1489 }
1490 EXPORT_SYMBOL_GPL(of_get_fb_videomode);
1491 #endif /* CONFIG_OF */
1492 #endif /* CONFIG_VIDEOMODE_HELPERS */
1493 
1494 #else
1495 int fb_parse_edid(unsigned char *edid, struct fb_var_screeninfo *var)
1496 {
1497 	return 1;
1498 }
1499 void fb_edid_to_monspecs(unsigned char *edid, struct fb_monspecs *specs)
1500 {
1501 	specs = NULL;
1502 }
1503 void fb_edid_add_monspecs(unsigned char *edid, struct fb_monspecs *specs)
1504 {
1505 }
1506 void fb_destroy_modedb(struct fb_videomode *modedb)
1507 {
1508 }
1509 int fb_get_mode(int flags, u32 val, struct fb_var_screeninfo *var,
1510 		struct fb_info *info)
1511 {
1512 	return -EINVAL;
1513 }
1514 #endif /* CONFIG_FB_MODE_HELPERS */
1515 
1516 /*
1517  * fb_validate_mode - validates var against monitor capabilities
1518  * @var: pointer to fb_var_screeninfo
1519  * @info: pointer to fb_info
1520  *
1521  * DESCRIPTION:
1522  * Validates video mode against monitor capabilities specified in
1523  * info->monspecs.
1524  *
1525  * REQUIRES:
1526  * A valid info->monspecs.
1527  */
1528 int fb_validate_mode(const struct fb_var_screeninfo *var, struct fb_info *info)
1529 {
1530 	u32 hfreq, vfreq, htotal, vtotal, pixclock;
1531 	u32 hfmin, hfmax, vfmin, vfmax, dclkmin, dclkmax;
1532 
1533 	/*
1534 	 * If monspecs are invalid, use values that are enough
1535 	 * for 640x480@60
1536 	 */
1537 	if (!info->monspecs.hfmax || !info->monspecs.vfmax ||
1538 	    !info->monspecs.dclkmax ||
1539 	    info->monspecs.hfmax < info->monspecs.hfmin ||
1540 	    info->monspecs.vfmax < info->monspecs.vfmin ||
1541 	    info->monspecs.dclkmax < info->monspecs.dclkmin) {
1542 		hfmin = 29000; hfmax = 30000;
1543 		vfmin = 60; vfmax = 60;
1544 		dclkmin = 0; dclkmax = 25000000;
1545 	} else {
1546 		hfmin = info->monspecs.hfmin;
1547 		hfmax = info->monspecs.hfmax;
1548 		vfmin = info->monspecs.vfmin;
1549 		vfmax = info->monspecs.vfmax;
1550 		dclkmin = info->monspecs.dclkmin;
1551 		dclkmax = info->monspecs.dclkmax;
1552 	}
1553 
1554 	if (!var->pixclock)
1555 		return -EINVAL;
1556 	pixclock = PICOS2KHZ(var->pixclock) * 1000;
1557 
1558 	htotal = var->xres + var->right_margin + var->hsync_len +
1559 		var->left_margin;
1560 	vtotal = var->yres + var->lower_margin + var->vsync_len +
1561 		var->upper_margin;
1562 
1563 	if (var->vmode & FB_VMODE_INTERLACED)
1564 		vtotal /= 2;
1565 	if (var->vmode & FB_VMODE_DOUBLE)
1566 		vtotal *= 2;
1567 
1568 	hfreq = pixclock/htotal;
1569 	hfreq = (hfreq + 500) / 1000 * 1000;
1570 
1571 	vfreq = hfreq/vtotal;
1572 
1573 	return (vfreq < vfmin || vfreq > vfmax ||
1574 		hfreq < hfmin || hfreq > hfmax ||
1575 		pixclock < dclkmin || pixclock > dclkmax) ?
1576 		-EINVAL : 0;
1577 }
1578 
1579 #if defined(CONFIG_FIRMWARE_EDID) && defined(CONFIG_X86)
1580 
1581 /*
1582  * We need to ensure that the EDID block is only returned for
1583  * the primary graphics adapter.
1584  */
1585 
1586 const unsigned char *fb_firmware_edid(struct device *device)
1587 {
1588 	struct pci_dev *dev = NULL;
1589 	struct resource *res = NULL;
1590 	unsigned char *edid = NULL;
1591 
1592 	if (device)
1593 		dev = to_pci_dev(device);
1594 
1595 	if (dev)
1596 		res = &dev->resource[PCI_ROM_RESOURCE];
1597 
1598 	if (res && res->flags & IORESOURCE_ROM_SHADOW)
1599 		edid = edid_info.dummy;
1600 
1601 	return edid;
1602 }
1603 #else
1604 const unsigned char *fb_firmware_edid(struct device *device)
1605 {
1606 	return NULL;
1607 }
1608 #endif
1609 EXPORT_SYMBOL(fb_firmware_edid);
1610 
1611 EXPORT_SYMBOL(fb_parse_edid);
1612 EXPORT_SYMBOL(fb_edid_to_monspecs);
1613 EXPORT_SYMBOL(fb_edid_add_monspecs);
1614 EXPORT_SYMBOL(fb_get_mode);
1615 EXPORT_SYMBOL(fb_validate_mode);
1616 EXPORT_SYMBOL(fb_destroy_modedb);
1617