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