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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 
copy_string(unsigned char * c,unsigned char * s)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 
edid_is_serial_block(unsigned char * block)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 
edid_is_ascii_block(unsigned char * block)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 
edid_is_limits_block(unsigned char * block)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 
edid_is_monitor_block(unsigned char * block)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 
edid_is_timing_block(unsigned char * block)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 
check_edid(unsigned char * edid)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 
fix_edid(unsigned char * edid,int fix)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 
edid_checksum(unsigned char * edid)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 
edid_check_header(unsigned char * edid)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 
parse_vendor_block(unsigned char * block,struct fb_monspecs * specs)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 
get_dpms_capabilities(unsigned char flags,struct fb_monspecs * specs)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 
get_chroma(unsigned char * block,struct fb_monspecs * specs)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 
calc_mode_timings(int xres,int yres,int refresh,struct fb_videomode * mode)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 
get_est_timing(unsigned char * block,struct fb_videomode * mode)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 
get_std_timing(unsigned char * block,struct fb_videomode * mode,int ver,int rev)498 static int get_std_timing(unsigned char *block, struct fb_videomode *mode,
499 		int ver, int rev)
500 {
501 	int xres, yres = 0, refresh, ratio, i;
502 
503 	xres = (block[0] + 31) * 8;
504 	if (xres <= 256)
505 		return 0;
506 
507 	ratio = (block[1] & 0xc0) >> 6;
508 	switch (ratio) {
509 	case 0:
510 		/* in EDID 1.3 the meaning of 0 changed to 16:10 (prior 1:1) */
511 		if (ver < 1 || (ver == 1 && rev < 3))
512 			yres = xres;
513 		else
514 			yres = (xres * 10)/16;
515 		break;
516 	case 1:
517 		yres = (xres * 3)/4;
518 		break;
519 	case 2:
520 		yres = (xres * 4)/5;
521 		break;
522 	case 3:
523 		yres = (xres * 9)/16;
524 		break;
525 	}
526 	refresh = (block[1] & 0x3f) + 60;
527 
528 	DPRINTK("      %dx%d@%dHz\n", xres, yres, refresh);
529 	for (i = 0; i < VESA_MODEDB_SIZE; i++) {
530 		if (vesa_modes[i].xres == xres &&
531 		    vesa_modes[i].yres == yres &&
532 		    vesa_modes[i].refresh == refresh) {
533 			*mode = vesa_modes[i];
534 			mode->flag |= FB_MODE_IS_STANDARD;
535 			return 1;
536 		}
537 	}
538 	calc_mode_timings(xres, yres, refresh, mode);
539 	return 1;
540 }
541 
get_dst_timing(unsigned char * block,struct fb_videomode * mode,int ver,int rev)542 static int get_dst_timing(unsigned char *block,
543 			  struct fb_videomode *mode, int ver, int rev)
544 {
545 	int j, num = 0;
546 
547 	for (j = 0; j < 6; j++, block += STD_TIMING_DESCRIPTION_SIZE)
548 		num += get_std_timing(block, &mode[num], ver, rev);
549 
550 	return num;
551 }
552 
get_detailed_timing(unsigned char * block,struct fb_videomode * mode)553 static void get_detailed_timing(unsigned char *block,
554 				struct fb_videomode *mode)
555 {
556 	mode->xres = H_ACTIVE;
557 	mode->yres = V_ACTIVE;
558 	mode->pixclock = PIXEL_CLOCK;
559 	mode->pixclock /= 1000;
560 	mode->pixclock = KHZ2PICOS(mode->pixclock);
561 	mode->right_margin = H_SYNC_OFFSET;
562 	mode->left_margin = (H_ACTIVE + H_BLANKING) -
563 		(H_ACTIVE + H_SYNC_OFFSET + H_SYNC_WIDTH);
564 	mode->upper_margin = V_BLANKING - V_SYNC_OFFSET -
565 		V_SYNC_WIDTH;
566 	mode->lower_margin = V_SYNC_OFFSET;
567 	mode->hsync_len = H_SYNC_WIDTH;
568 	mode->vsync_len = V_SYNC_WIDTH;
569 	if (HSYNC_POSITIVE)
570 		mode->sync |= FB_SYNC_HOR_HIGH_ACT;
571 	if (VSYNC_POSITIVE)
572 		mode->sync |= FB_SYNC_VERT_HIGH_ACT;
573 	mode->refresh = PIXEL_CLOCK/((H_ACTIVE + H_BLANKING) *
574 				     (V_ACTIVE + V_BLANKING));
575 	if (INTERLACED) {
576 		mode->yres *= 2;
577 		mode->upper_margin *= 2;
578 		mode->lower_margin *= 2;
579 		mode->vsync_len *= 2;
580 		mode->vmode |= FB_VMODE_INTERLACED;
581 	}
582 	mode->flag = FB_MODE_IS_DETAILED;
583 
584 	DPRINTK("      %d MHz ",  PIXEL_CLOCK/1000000);
585 	DPRINTK("%d %d %d %d ", H_ACTIVE, H_ACTIVE + H_SYNC_OFFSET,
586 	       H_ACTIVE + H_SYNC_OFFSET + H_SYNC_WIDTH, H_ACTIVE + H_BLANKING);
587 	DPRINTK("%d %d %d %d ", V_ACTIVE, V_ACTIVE + V_SYNC_OFFSET,
588 	       V_ACTIVE + V_SYNC_OFFSET + V_SYNC_WIDTH, V_ACTIVE + V_BLANKING);
589 	DPRINTK("%sHSync %sVSync\n\n", (HSYNC_POSITIVE) ? "+" : "-",
590 	       (VSYNC_POSITIVE) ? "+" : "-");
591 }
592 
593 /**
594  * fb_create_modedb - create video mode database
595  * @edid: EDID data
596  * @dbsize: database size
597  *
598  * RETURNS: struct fb_videomode, @dbsize contains length of database
599  *
600  * DESCRIPTION:
601  * This function builds a mode database using the contents of the EDID
602  * data
603  */
fb_create_modedb(unsigned char * edid,int * dbsize)604 static struct fb_videomode *fb_create_modedb(unsigned char *edid, int *dbsize)
605 {
606 	struct fb_videomode *mode, *m;
607 	unsigned char *block;
608 	int num = 0, i, first = 1;
609 	int ver, rev;
610 
611 	ver = edid[EDID_STRUCT_VERSION];
612 	rev = edid[EDID_STRUCT_REVISION];
613 
614 	mode = kzalloc(50 * sizeof(struct fb_videomode), GFP_KERNEL);
615 	if (mode == NULL)
616 		return NULL;
617 
618 	if (edid == NULL || !edid_checksum(edid) ||
619 	    !edid_check_header(edid)) {
620 		kfree(mode);
621 		return NULL;
622 	}
623 
624 	*dbsize = 0;
625 
626 	DPRINTK("   Detailed Timings\n");
627 	block = edid + DETAILED_TIMING_DESCRIPTIONS_START;
628 	for (i = 0; i < 4; i++, block+= DETAILED_TIMING_DESCRIPTION_SIZE) {
629 		if (!(block[0] == 0x00 && block[1] == 0x00)) {
630 			get_detailed_timing(block, &mode[num]);
631 			if (first) {
632 			        mode[num].flag |= FB_MODE_IS_FIRST;
633 				first = 0;
634 			}
635 			num++;
636 		}
637 	}
638 
639 	DPRINTK("   Supported VESA Modes\n");
640 	block = edid + ESTABLISHED_TIMING_1;
641 	num += get_est_timing(block, &mode[num]);
642 
643 	DPRINTK("   Standard Timings\n");
644 	block = edid + STD_TIMING_DESCRIPTIONS_START;
645 	for (i = 0; i < STD_TIMING; i++, block += STD_TIMING_DESCRIPTION_SIZE)
646 		num += get_std_timing(block, &mode[num], ver, rev);
647 
648 	block = edid + DETAILED_TIMING_DESCRIPTIONS_START;
649 	for (i = 0; i < 4; i++, block+= DETAILED_TIMING_DESCRIPTION_SIZE) {
650 		if (block[0] == 0x00 && block[1] == 0x00 && block[3] == 0xfa)
651 			num += get_dst_timing(block + 5, &mode[num], ver, rev);
652 	}
653 
654 	/* Yikes, EDID data is totally useless */
655 	if (!num) {
656 		kfree(mode);
657 		return NULL;
658 	}
659 
660 	*dbsize = num;
661 	m = kmalloc(num * sizeof(struct fb_videomode), GFP_KERNEL);
662 	if (!m)
663 		return mode;
664 	memmove(m, mode, num * sizeof(struct fb_videomode));
665 	kfree(mode);
666 	return m;
667 }
668 
669 /**
670  * fb_destroy_modedb - destroys mode database
671  * @modedb: mode database to destroy
672  *
673  * DESCRIPTION:
674  * Destroy mode database created by fb_create_modedb
675  */
fb_destroy_modedb(struct fb_videomode * modedb)676 void fb_destroy_modedb(struct fb_videomode *modedb)
677 {
678 	kfree(modedb);
679 }
680 
fb_get_monitor_limits(unsigned char * edid,struct fb_monspecs * specs)681 static int fb_get_monitor_limits(unsigned char *edid, struct fb_monspecs *specs)
682 {
683 	int i, retval = 1;
684 	unsigned char *block;
685 
686 	block = edid + DETAILED_TIMING_DESCRIPTIONS_START;
687 
688 	DPRINTK("      Monitor Operating Limits: ");
689 
690 	for (i = 0; i < 4; i++, block += DETAILED_TIMING_DESCRIPTION_SIZE) {
691 		if (edid_is_limits_block(block)) {
692 			specs->hfmin = H_MIN_RATE * 1000;
693 			specs->hfmax = H_MAX_RATE * 1000;
694 			specs->vfmin = V_MIN_RATE;
695 			specs->vfmax = V_MAX_RATE;
696 			specs->dclkmax = MAX_PIXEL_CLOCK * 1000000;
697 			specs->gtf = (GTF_SUPPORT) ? 1 : 0;
698 			retval = 0;
699 			DPRINTK("From EDID\n");
700 			break;
701 		}
702 	}
703 
704 	/* estimate monitor limits based on modes supported */
705 	if (retval) {
706 		struct fb_videomode *modes, *mode;
707 		int num_modes, hz, hscan, pixclock;
708 		int vtotal, htotal;
709 
710 		modes = fb_create_modedb(edid, &num_modes);
711 		if (!modes) {
712 			DPRINTK("None Available\n");
713 			return 1;
714 		}
715 
716 		retval = 0;
717 		for (i = 0; i < num_modes; i++) {
718 			mode = &modes[i];
719 			pixclock = PICOS2KHZ(modes[i].pixclock) * 1000;
720 			htotal = mode->xres + mode->right_margin + mode->hsync_len
721 				+ mode->left_margin;
722 			vtotal = mode->yres + mode->lower_margin + mode->vsync_len
723 				+ mode->upper_margin;
724 
725 			if (mode->vmode & FB_VMODE_INTERLACED)
726 				vtotal /= 2;
727 
728 			if (mode->vmode & FB_VMODE_DOUBLE)
729 				vtotal *= 2;
730 
731 			hscan = (pixclock + htotal / 2) / htotal;
732 			hscan = (hscan + 500) / 1000 * 1000;
733 			hz = (hscan + vtotal / 2) / vtotal;
734 
735 			if (specs->dclkmax == 0 || specs->dclkmax < pixclock)
736 				specs->dclkmax = pixclock;
737 
738 			if (specs->dclkmin == 0 || specs->dclkmin > pixclock)
739 				specs->dclkmin = pixclock;
740 
741 			if (specs->hfmax == 0 || specs->hfmax < hscan)
742 				specs->hfmax = hscan;
743 
744 			if (specs->hfmin == 0 || specs->hfmin > hscan)
745 				specs->hfmin = hscan;
746 
747 			if (specs->vfmax == 0 || specs->vfmax < hz)
748 				specs->vfmax = hz;
749 
750 			if (specs->vfmin == 0 || specs->vfmin > hz)
751 				specs->vfmin = hz;
752 		}
753 		DPRINTK("Extrapolated\n");
754 		fb_destroy_modedb(modes);
755 	}
756 	DPRINTK("           H: %d-%dKHz V: %d-%dHz DCLK: %dMHz\n",
757 		specs->hfmin/1000, specs->hfmax/1000, specs->vfmin,
758 		specs->vfmax, specs->dclkmax/1000000);
759 	return retval;
760 }
761 
get_monspecs(unsigned char * edid,struct fb_monspecs * specs)762 static void get_monspecs(unsigned char *edid, struct fb_monspecs *specs)
763 {
764 	unsigned char c, *block;
765 
766 	block = edid + EDID_STRUCT_DISPLAY;
767 
768 	fb_get_monitor_limits(edid, specs);
769 
770 	c = block[0] & 0x80;
771 	specs->input = 0;
772 	if (c) {
773 		specs->input |= FB_DISP_DDI;
774 		DPRINTK("      Digital Display Input");
775 	} else {
776 		DPRINTK("      Analog Display Input: Input Voltage - ");
777 		switch ((block[0] & 0x60) >> 5) {
778 		case 0:
779 			DPRINTK("0.700V/0.300V");
780 			specs->input |= FB_DISP_ANA_700_300;
781 			break;
782 		case 1:
783 			DPRINTK("0.714V/0.286V");
784 			specs->input |= FB_DISP_ANA_714_286;
785 			break;
786 		case 2:
787 			DPRINTK("1.000V/0.400V");
788 			specs->input |= FB_DISP_ANA_1000_400;
789 			break;
790 		case 3:
791 			DPRINTK("0.700V/0.000V");
792 			specs->input |= FB_DISP_ANA_700_000;
793 			break;
794 		}
795 	}
796 	DPRINTK("\n      Sync: ");
797 	c = block[0] & 0x10;
798 	if (c)
799 		DPRINTK("      Configurable signal level\n");
800 	c = block[0] & 0x0f;
801 	specs->signal = 0;
802 	if (c & 0x10) {
803 		DPRINTK("Blank to Blank ");
804 		specs->signal |= FB_SIGNAL_BLANK_BLANK;
805 	}
806 	if (c & 0x08) {
807 		DPRINTK("Separate ");
808 		specs->signal |= FB_SIGNAL_SEPARATE;
809 	}
810 	if (c & 0x04) {
811 		DPRINTK("Composite ");
812 		specs->signal |= FB_SIGNAL_COMPOSITE;
813 	}
814 	if (c & 0x02) {
815 		DPRINTK("Sync on Green ");
816 		specs->signal |= FB_SIGNAL_SYNC_ON_GREEN;
817 	}
818 	if (c & 0x01) {
819 		DPRINTK("Serration on ");
820 		specs->signal |= FB_SIGNAL_SERRATION_ON;
821 	}
822 	DPRINTK("\n");
823 	specs->max_x = block[1];
824 	specs->max_y = block[2];
825 	DPRINTK("      Max H-size in cm: ");
826 	if (specs->max_x)
827 		DPRINTK("%d\n", specs->max_x);
828 	else
829 		DPRINTK("variable\n");
830 	DPRINTK("      Max V-size in cm: ");
831 	if (specs->max_y)
832 		DPRINTK("%d\n", specs->max_y);
833 	else
834 		DPRINTK("variable\n");
835 
836 	c = block[3];
837 	specs->gamma = c+100;
838 	DPRINTK("      Gamma: ");
839 	DPRINTK("%d.%d\n", specs->gamma/100, specs->gamma % 100);
840 
841 	get_dpms_capabilities(block[4], specs);
842 
843 	switch ((block[4] & 0x18) >> 3) {
844 	case 0:
845 		DPRINTK("      Monochrome/Grayscale\n");
846 		specs->input |= FB_DISP_MONO;
847 		break;
848 	case 1:
849 		DPRINTK("      RGB Color Display\n");
850 		specs->input |= FB_DISP_RGB;
851 		break;
852 	case 2:
853 		DPRINTK("      Non-RGB Multicolor Display\n");
854 		specs->input |= FB_DISP_MULTI;
855 		break;
856 	default:
857 		DPRINTK("      Unknown\n");
858 		specs->input |= FB_DISP_UNKNOWN;
859 		break;
860 	}
861 
862 	get_chroma(block, specs);
863 
864 	specs->misc = 0;
865 	c = block[4] & 0x7;
866 	if (c & 0x04) {
867 		DPRINTK("      Default color format is primary\n");
868 		specs->misc |= FB_MISC_PRIM_COLOR;
869 	}
870 	if (c & 0x02) {
871 		DPRINTK("      First DETAILED Timing is preferred\n");
872 		specs->misc |= FB_MISC_1ST_DETAIL;
873 	}
874 	if (c & 0x01) {
875 		printk("      Display is GTF capable\n");
876 		specs->gtf = 1;
877 	}
878 }
879 
fb_parse_edid(unsigned char * edid,struct fb_var_screeninfo * var)880 int fb_parse_edid(unsigned char *edid, struct fb_var_screeninfo *var)
881 {
882 	int i;
883 	unsigned char *block;
884 
885 	if (edid == NULL || var == NULL)
886 		return 1;
887 
888 	if (!(edid_checksum(edid)))
889 		return 1;
890 
891 	if (!(edid_check_header(edid)))
892 		return 1;
893 
894 	block = edid + DETAILED_TIMING_DESCRIPTIONS_START;
895 
896 	for (i = 0; i < 4; i++, block += DETAILED_TIMING_DESCRIPTION_SIZE) {
897 		if (edid_is_timing_block(block)) {
898 			var->xres = var->xres_virtual = H_ACTIVE;
899 			var->yres = var->yres_virtual = V_ACTIVE;
900 			var->height = var->width = 0;
901 			var->right_margin = H_SYNC_OFFSET;
902 			var->left_margin = (H_ACTIVE + H_BLANKING) -
903 				(H_ACTIVE + H_SYNC_OFFSET + H_SYNC_WIDTH);
904 			var->upper_margin = V_BLANKING - V_SYNC_OFFSET -
905 				V_SYNC_WIDTH;
906 			var->lower_margin = V_SYNC_OFFSET;
907 			var->hsync_len = H_SYNC_WIDTH;
908 			var->vsync_len = V_SYNC_WIDTH;
909 			var->pixclock = PIXEL_CLOCK;
910 			var->pixclock /= 1000;
911 			var->pixclock = KHZ2PICOS(var->pixclock);
912 
913 			if (HSYNC_POSITIVE)
914 				var->sync |= FB_SYNC_HOR_HIGH_ACT;
915 			if (VSYNC_POSITIVE)
916 				var->sync |= FB_SYNC_VERT_HIGH_ACT;
917 			return 0;
918 		}
919 	}
920 	return 1;
921 }
922 
fb_edid_to_monspecs(unsigned char * edid,struct fb_monspecs * specs)923 void fb_edid_to_monspecs(unsigned char *edid, struct fb_monspecs *specs)
924 {
925 	unsigned char *block;
926 	int i, found = 0;
927 
928 	if (edid == NULL)
929 		return;
930 
931 	if (!(edid_checksum(edid)))
932 		return;
933 
934 	if (!(edid_check_header(edid)))
935 		return;
936 
937 	memset(specs, 0, sizeof(struct fb_monspecs));
938 
939 	specs->version = edid[EDID_STRUCT_VERSION];
940 	specs->revision = edid[EDID_STRUCT_REVISION];
941 
942 	DPRINTK("========================================\n");
943 	DPRINTK("Display Information (EDID)\n");
944 	DPRINTK("========================================\n");
945 	DPRINTK("   EDID Version %d.%d\n", (int) specs->version,
946 	       (int) specs->revision);
947 
948 	parse_vendor_block(edid + ID_MANUFACTURER_NAME, specs);
949 
950 	block = edid + DETAILED_TIMING_DESCRIPTIONS_START;
951 	for (i = 0; i < 4; i++, block += DETAILED_TIMING_DESCRIPTION_SIZE) {
952 		if (edid_is_serial_block(block)) {
953 			copy_string(block, specs->serial_no);
954 			DPRINTK("   Serial Number: %s\n", specs->serial_no);
955 		} else if (edid_is_ascii_block(block)) {
956 			copy_string(block, specs->ascii);
957 			DPRINTK("   ASCII Block: %s\n", specs->ascii);
958 		} else if (edid_is_monitor_block(block)) {
959 			copy_string(block, specs->monitor);
960 			DPRINTK("   Monitor Name: %s\n", specs->monitor);
961 		}
962 	}
963 
964 	DPRINTK("   Display Characteristics:\n");
965 	get_monspecs(edid, specs);
966 
967 	specs->modedb = fb_create_modedb(edid, &specs->modedb_len);
968 
969 	/*
970 	 * Workaround for buggy EDIDs that sets that the first
971 	 * detailed timing is preferred but has not detailed
972 	 * timing specified
973 	 */
974 	for (i = 0; i < specs->modedb_len; i++) {
975 		if (specs->modedb[i].flag & FB_MODE_IS_DETAILED) {
976 			found = 1;
977 			break;
978 		}
979 	}
980 
981 	if (!found)
982 		specs->misc &= ~FB_MISC_1ST_DETAIL;
983 
984 	DPRINTK("========================================\n");
985 }
986 
987 /**
988  * fb_edid_add_monspecs() - add monitor video modes from E-EDID data
989  * @edid:	128 byte array with an E-EDID block
990  * @spacs:	monitor specs to be extended
991  */
fb_edid_add_monspecs(unsigned char * edid,struct fb_monspecs * specs)992 void fb_edid_add_monspecs(unsigned char *edid, struct fb_monspecs *specs)
993 {
994 	unsigned char *block;
995 	struct fb_videomode *m;
996 	int num = 0, i;
997 	u8 svd[64], edt[(128 - 4) / DETAILED_TIMING_DESCRIPTION_SIZE];
998 	u8 pos = 4, svd_n = 0;
999 
1000 	if (!edid)
1001 		return;
1002 
1003 	if (!edid_checksum(edid))
1004 		return;
1005 
1006 	if (edid[0] != 0x2 ||
1007 	    edid[2] < 4 || edid[2] > 128 - DETAILED_TIMING_DESCRIPTION_SIZE)
1008 		return;
1009 
1010 	DPRINTK("  Short Video Descriptors\n");
1011 
1012 	while (pos < edid[2]) {
1013 		u8 len = edid[pos] & 0x1f, type = (edid[pos] >> 5) & 7;
1014 		pr_debug("Data block %u of %u bytes\n", type, len);
1015 		if (type == 2)
1016 			for (i = pos; i < pos + len; i++) {
1017 				u8 idx = edid[pos + i] & 0x7f;
1018 				svd[svd_n++] = idx;
1019 				pr_debug("N%sative mode #%d\n",
1020 					 edid[pos + i] & 0x80 ? "" : "on-n", idx);
1021 			}
1022 		pos += len + 1;
1023 	}
1024 
1025 	block = edid + edid[2];
1026 
1027 	DPRINTK("  Extended Detailed Timings\n");
1028 
1029 	for (i = 0; i < (128 - edid[2]) / DETAILED_TIMING_DESCRIPTION_SIZE;
1030 	     i++, block += DETAILED_TIMING_DESCRIPTION_SIZE)
1031 		if (PIXEL_CLOCK)
1032 			edt[num++] = block - edid;
1033 
1034 	/* Yikes, EDID data is totally useless */
1035 	if (!(num + svd_n))
1036 		return;
1037 
1038 	m = kzalloc((specs->modedb_len + num + svd_n) *
1039 		       sizeof(struct fb_videomode), GFP_KERNEL);
1040 
1041 	if (!m)
1042 		return;
1043 
1044 	memcpy(m, specs->modedb, specs->modedb_len * sizeof(struct fb_videomode));
1045 
1046 	for (i = specs->modedb_len; i < specs->modedb_len + num; i++) {
1047 		get_detailed_timing(edid + edt[i - specs->modedb_len], &m[i]);
1048 		if (i == specs->modedb_len)
1049 			m[i].flag |= FB_MODE_IS_FIRST;
1050 		pr_debug("Adding %ux%u@%u\n", m[i].xres, m[i].yres, m[i].refresh);
1051 	}
1052 
1053 	for (i = specs->modedb_len + num; i < specs->modedb_len + num + svd_n; i++) {
1054 		int idx = svd[i - specs->modedb_len - num];
1055 		if (!idx || idx > 63) {
1056 			pr_warning("Reserved SVD code %d\n", idx);
1057 		} else if (idx > ARRAY_SIZE(cea_modes) || !cea_modes[idx].xres) {
1058 			pr_warning("Unimplemented SVD code %d\n", idx);
1059 		} else {
1060 			memcpy(&m[i], cea_modes + idx, sizeof(m[i]));
1061 			pr_debug("Adding SVD #%d: %ux%u@%u\n", idx,
1062 				 m[i].xres, m[i].yres, m[i].refresh);
1063 		}
1064 	}
1065 
1066 	kfree(specs->modedb);
1067 	specs->modedb = m;
1068 	specs->modedb_len = specs->modedb_len + num + svd_n;
1069 }
1070 
1071 /*
1072  * VESA Generalized Timing Formula (GTF)
1073  */
1074 
1075 #define FLYBACK                     550
1076 #define V_FRONTPORCH                1
1077 #define H_OFFSET                    40
1078 #define H_SCALEFACTOR               20
1079 #define H_BLANKSCALE                128
1080 #define H_GRADIENT                  600
1081 #define C_VAL                       30
1082 #define M_VAL                       300
1083 
1084 struct __fb_timings {
1085 	u32 dclk;
1086 	u32 hfreq;
1087 	u32 vfreq;
1088 	u32 hactive;
1089 	u32 vactive;
1090 	u32 hblank;
1091 	u32 vblank;
1092 	u32 htotal;
1093 	u32 vtotal;
1094 };
1095 
1096 /**
1097  * fb_get_vblank - get vertical blank time
1098  * @hfreq: horizontal freq
1099  *
1100  * DESCRIPTION:
1101  * vblank = right_margin + vsync_len + left_margin
1102  *
1103  *    given: right_margin = 1 (V_FRONTPORCH)
1104  *           vsync_len    = 3
1105  *           flyback      = 550
1106  *
1107  *                          flyback * hfreq
1108  *           left_margin  = --------------- - vsync_len
1109  *                           1000000
1110  */
fb_get_vblank(u32 hfreq)1111 static u32 fb_get_vblank(u32 hfreq)
1112 {
1113 	u32 vblank;
1114 
1115 	vblank = (hfreq * FLYBACK)/1000;
1116 	vblank = (vblank + 500)/1000;
1117 	return (vblank + V_FRONTPORCH);
1118 }
1119 
1120 /**
1121  * fb_get_hblank_by_freq - get horizontal blank time given hfreq
1122  * @hfreq: horizontal freq
1123  * @xres: horizontal resolution in pixels
1124  *
1125  * DESCRIPTION:
1126  *
1127  *           xres * duty_cycle
1128  * hblank = ------------------
1129  *           100 - duty_cycle
1130  *
1131  * duty cycle = percent of htotal assigned to inactive display
1132  * duty cycle = C - (M/Hfreq)
1133  *
1134  * where: C = ((offset - scale factor) * blank_scale)
1135  *            -------------------------------------- + scale factor
1136  *                        256
1137  *        M = blank_scale * gradient
1138  *
1139  */
fb_get_hblank_by_hfreq(u32 hfreq,u32 xres)1140 static u32 fb_get_hblank_by_hfreq(u32 hfreq, u32 xres)
1141 {
1142 	u32 c_val, m_val, duty_cycle, hblank;
1143 
1144 	c_val = (((H_OFFSET - H_SCALEFACTOR) * H_BLANKSCALE)/256 +
1145 		 H_SCALEFACTOR) * 1000;
1146 	m_val = (H_BLANKSCALE * H_GRADIENT)/256;
1147 	m_val = (m_val * 1000000)/hfreq;
1148 	duty_cycle = c_val - m_val;
1149 	hblank = (xres * duty_cycle)/(100000 - duty_cycle);
1150 	return (hblank);
1151 }
1152 
1153 /**
1154  * fb_get_hblank_by_dclk - get horizontal blank time given pixelclock
1155  * @dclk: pixelclock in Hz
1156  * @xres: horizontal resolution in pixels
1157  *
1158  * DESCRIPTION:
1159  *
1160  *           xres * duty_cycle
1161  * hblank = ------------------
1162  *           100 - duty_cycle
1163  *
1164  * duty cycle = percent of htotal assigned to inactive display
1165  * duty cycle = C - (M * h_period)
1166  *
1167  * where: h_period = SQRT(100 - C + (0.4 * xres * M)/dclk) + C - 100
1168  *                   -----------------------------------------------
1169  *                                    2 * M
1170  *        M = 300;
1171  *        C = 30;
1172 
1173  */
fb_get_hblank_by_dclk(u32 dclk,u32 xres)1174 static u32 fb_get_hblank_by_dclk(u32 dclk, u32 xres)
1175 {
1176 	u32 duty_cycle, h_period, hblank;
1177 
1178 	dclk /= 1000;
1179 	h_period = 100 - C_VAL;
1180 	h_period *= h_period;
1181 	h_period += (M_VAL * xres * 2 * 1000)/(5 * dclk);
1182 	h_period *= 10000;
1183 
1184 	h_period = int_sqrt(h_period);
1185 	h_period -= (100 - C_VAL) * 100;
1186 	h_period *= 1000;
1187 	h_period /= 2 * M_VAL;
1188 
1189 	duty_cycle = C_VAL * 1000 - (M_VAL * h_period)/100;
1190 	hblank = (xres * duty_cycle)/(100000 - duty_cycle) + 8;
1191 	hblank &= ~15;
1192 	return (hblank);
1193 }
1194 
1195 /**
1196  * fb_get_hfreq - estimate hsync
1197  * @vfreq: vertical refresh rate
1198  * @yres: vertical resolution
1199  *
1200  * DESCRIPTION:
1201  *
1202  *          (yres + front_port) * vfreq * 1000000
1203  * hfreq = -------------------------------------
1204  *          (1000000 - (vfreq * FLYBACK)
1205  *
1206  */
1207 
fb_get_hfreq(u32 vfreq,u32 yres)1208 static u32 fb_get_hfreq(u32 vfreq, u32 yres)
1209 {
1210 	u32 divisor, hfreq;
1211 
1212 	divisor = (1000000 - (vfreq * FLYBACK))/1000;
1213 	hfreq = (yres + V_FRONTPORCH) * vfreq  * 1000;
1214 	return (hfreq/divisor);
1215 }
1216 
fb_timings_vfreq(struct __fb_timings * timings)1217 static void fb_timings_vfreq(struct __fb_timings *timings)
1218 {
1219 	timings->hfreq = fb_get_hfreq(timings->vfreq, timings->vactive);
1220 	timings->vblank = fb_get_vblank(timings->hfreq);
1221 	timings->vtotal = timings->vactive + timings->vblank;
1222 	timings->hblank = fb_get_hblank_by_hfreq(timings->hfreq,
1223 						 timings->hactive);
1224 	timings->htotal = timings->hactive + timings->hblank;
1225 	timings->dclk = timings->htotal * timings->hfreq;
1226 }
1227 
fb_timings_hfreq(struct __fb_timings * timings)1228 static void fb_timings_hfreq(struct __fb_timings *timings)
1229 {
1230 	timings->vblank = fb_get_vblank(timings->hfreq);
1231 	timings->vtotal = timings->vactive + timings->vblank;
1232 	timings->vfreq = timings->hfreq/timings->vtotal;
1233 	timings->hblank = fb_get_hblank_by_hfreq(timings->hfreq,
1234 						 timings->hactive);
1235 	timings->htotal = timings->hactive + timings->hblank;
1236 	timings->dclk = timings->htotal * timings->hfreq;
1237 }
1238 
fb_timings_dclk(struct __fb_timings * timings)1239 static void fb_timings_dclk(struct __fb_timings *timings)
1240 {
1241 	timings->hblank = fb_get_hblank_by_dclk(timings->dclk,
1242 						timings->hactive);
1243 	timings->htotal = timings->hactive + timings->hblank;
1244 	timings->hfreq = timings->dclk/timings->htotal;
1245 	timings->vblank = fb_get_vblank(timings->hfreq);
1246 	timings->vtotal = timings->vactive + timings->vblank;
1247 	timings->vfreq = timings->hfreq/timings->vtotal;
1248 }
1249 
1250 /*
1251  * fb_get_mode - calculates video mode using VESA GTF
1252  * @flags: if: 0 - maximize vertical refresh rate
1253  *             1 - vrefresh-driven calculation;
1254  *             2 - hscan-driven calculation;
1255  *             3 - pixelclock-driven calculation;
1256  * @val: depending on @flags, ignored, vrefresh, hsync or pixelclock
1257  * @var: pointer to fb_var_screeninfo
1258  * @info: pointer to fb_info
1259  *
1260  * DESCRIPTION:
1261  * Calculates video mode based on monitor specs using VESA GTF.
1262  * The GTF is best for VESA GTF compliant monitors but is
1263  * specifically formulated to work for older monitors as well.
1264  *
1265  * If @flag==0, the function will attempt to maximize the
1266  * refresh rate.  Otherwise, it will calculate timings based on
1267  * the flag and accompanying value.
1268  *
1269  * If FB_IGNOREMON bit is set in @flags, monitor specs will be
1270  * ignored and @var will be filled with the calculated timings.
1271  *
1272  * All calculations are based on the VESA GTF Spreadsheet
1273  * available at VESA's public ftp (http://www.vesa.org).
1274  *
1275  * NOTES:
1276  * The timings generated by the GTF will be different from VESA
1277  * DMT.  It might be a good idea to keep a table of standard
1278  * VESA modes as well.  The GTF may also not work for some displays,
1279  * such as, and especially, analog TV.
1280  *
1281  * REQUIRES:
1282  * A valid info->monspecs, otherwise 'safe numbers' will be used.
1283  */
fb_get_mode(int flags,u32 val,struct fb_var_screeninfo * var,struct fb_info * info)1284 int fb_get_mode(int flags, u32 val, struct fb_var_screeninfo *var, struct fb_info *info)
1285 {
1286 	struct __fb_timings *timings;
1287 	u32 interlace = 1, dscan = 1;
1288 	u32 hfmin, hfmax, vfmin, vfmax, dclkmin, dclkmax, err = 0;
1289 
1290 
1291 	timings = kzalloc(sizeof(struct __fb_timings), GFP_KERNEL);
1292 
1293 	if (!timings)
1294 		return -ENOMEM;
1295 
1296 	/*
1297 	 * If monspecs are invalid, use values that are enough
1298 	 * for 640x480@60
1299 	 */
1300 	if (!info || !info->monspecs.hfmax || !info->monspecs.vfmax ||
1301 	    !info->monspecs.dclkmax ||
1302 	    info->monspecs.hfmax < info->monspecs.hfmin ||
1303 	    info->monspecs.vfmax < info->monspecs.vfmin ||
1304 	    info->monspecs.dclkmax < info->monspecs.dclkmin) {
1305 		hfmin = 29000; hfmax = 30000;
1306 		vfmin = 60; vfmax = 60;
1307 		dclkmin = 0; dclkmax = 25000000;
1308 	} else {
1309 		hfmin = info->monspecs.hfmin;
1310 		hfmax = info->monspecs.hfmax;
1311 		vfmin = info->monspecs.vfmin;
1312 		vfmax = info->monspecs.vfmax;
1313 		dclkmin = info->monspecs.dclkmin;
1314 		dclkmax = info->monspecs.dclkmax;
1315 	}
1316 
1317 	timings->hactive = var->xres;
1318 	timings->vactive = var->yres;
1319 	if (var->vmode & FB_VMODE_INTERLACED) {
1320 		timings->vactive /= 2;
1321 		interlace = 2;
1322 	}
1323 	if (var->vmode & FB_VMODE_DOUBLE) {
1324 		timings->vactive *= 2;
1325 		dscan = 2;
1326 	}
1327 
1328 	switch (flags & ~FB_IGNOREMON) {
1329 	case FB_MAXTIMINGS: /* maximize refresh rate */
1330 		timings->hfreq = hfmax;
1331 		fb_timings_hfreq(timings);
1332 		if (timings->vfreq > vfmax) {
1333 			timings->vfreq = vfmax;
1334 			fb_timings_vfreq(timings);
1335 		}
1336 		if (timings->dclk > dclkmax) {
1337 			timings->dclk = dclkmax;
1338 			fb_timings_dclk(timings);
1339 		}
1340 		break;
1341 	case FB_VSYNCTIMINGS: /* vrefresh driven */
1342 		timings->vfreq = val;
1343 		fb_timings_vfreq(timings);
1344 		break;
1345 	case FB_HSYNCTIMINGS: /* hsync driven */
1346 		timings->hfreq = val;
1347 		fb_timings_hfreq(timings);
1348 		break;
1349 	case FB_DCLKTIMINGS: /* pixelclock driven */
1350 		timings->dclk = PICOS2KHZ(val) * 1000;
1351 		fb_timings_dclk(timings);
1352 		break;
1353 	default:
1354 		err = -EINVAL;
1355 
1356 	}
1357 
1358 	if (err || (!(flags & FB_IGNOREMON) &&
1359 	    (timings->vfreq < vfmin || timings->vfreq > vfmax ||
1360 	     timings->hfreq < hfmin || timings->hfreq > hfmax ||
1361 	     timings->dclk < dclkmin || timings->dclk > dclkmax))) {
1362 		err = -EINVAL;
1363 	} else {
1364 		var->pixclock = KHZ2PICOS(timings->dclk/1000);
1365 		var->hsync_len = (timings->htotal * 8)/100;
1366 		var->right_margin = (timings->hblank/2) - var->hsync_len;
1367 		var->left_margin = timings->hblank - var->right_margin -
1368 			var->hsync_len;
1369 		var->vsync_len = (3 * interlace)/dscan;
1370 		var->lower_margin = (1 * interlace)/dscan;
1371 		var->upper_margin = (timings->vblank * interlace)/dscan -
1372 			(var->vsync_len + var->lower_margin);
1373 	}
1374 
1375 	kfree(timings);
1376 	return err;
1377 }
1378 
1379 #ifdef CONFIG_VIDEOMODE_HELPERS
fb_videomode_from_videomode(const struct videomode * vm,struct fb_videomode * fbmode)1380 int fb_videomode_from_videomode(const struct videomode *vm,
1381 				struct fb_videomode *fbmode)
1382 {
1383 	unsigned int htotal, vtotal;
1384 
1385 	fbmode->xres = vm->hactive;
1386 	fbmode->left_margin = vm->hback_porch;
1387 	fbmode->right_margin = vm->hfront_porch;
1388 	fbmode->hsync_len = vm->hsync_len;
1389 
1390 	fbmode->yres = vm->vactive;
1391 	fbmode->upper_margin = vm->vback_porch;
1392 	fbmode->lower_margin = vm->vfront_porch;
1393 	fbmode->vsync_len = vm->vsync_len;
1394 
1395 	/* prevent division by zero in KHZ2PICOS macro */
1396 	fbmode->pixclock = vm->pixelclock ?
1397 			KHZ2PICOS(vm->pixelclock / 1000) : 0;
1398 
1399 	fbmode->sync = 0;
1400 	fbmode->vmode = 0;
1401 	if (vm->flags & DISPLAY_FLAGS_HSYNC_HIGH)
1402 		fbmode->sync |= FB_SYNC_HOR_HIGH_ACT;
1403 	if (vm->flags & DISPLAY_FLAGS_VSYNC_HIGH)
1404 		fbmode->sync |= FB_SYNC_VERT_HIGH_ACT;
1405 	if (vm->flags & DISPLAY_FLAGS_INTERLACED)
1406 		fbmode->vmode |= FB_VMODE_INTERLACED;
1407 	if (vm->flags & DISPLAY_FLAGS_DOUBLESCAN)
1408 		fbmode->vmode |= FB_VMODE_DOUBLE;
1409 	fbmode->flag = 0;
1410 
1411 	htotal = vm->hactive + vm->hfront_porch + vm->hback_porch +
1412 		 vm->hsync_len;
1413 	vtotal = vm->vactive + vm->vfront_porch + vm->vback_porch +
1414 		 vm->vsync_len;
1415 	/* prevent division by zero */
1416 	if (htotal && vtotal) {
1417 		fbmode->refresh = vm->pixelclock / (htotal * vtotal);
1418 	/* a mode must have htotal and vtotal != 0 or it is invalid */
1419 	} else {
1420 		fbmode->refresh = 0;
1421 		return -EINVAL;
1422 	}
1423 
1424 	return 0;
1425 }
1426 EXPORT_SYMBOL_GPL(fb_videomode_from_videomode);
1427 
1428 #ifdef CONFIG_OF
dump_fb_videomode(const struct fb_videomode * m)1429 static inline void dump_fb_videomode(const struct fb_videomode *m)
1430 {
1431 	pr_debug("fb_videomode = %ux%u@%uHz (%ukHz) %u %u %u %u %u %u %u %u %u\n",
1432 		 m->xres, m->yres, m->refresh, m->pixclock, m->left_margin,
1433 		 m->right_margin, m->upper_margin, m->lower_margin,
1434 		 m->hsync_len, m->vsync_len, m->sync, m->vmode, m->flag);
1435 }
1436 
1437 /**
1438  * of_get_fb_videomode - get a fb_videomode from devicetree
1439  * @np: device_node with the timing specification
1440  * @fb: will be set to the return value
1441  * @index: index into the list of display timings in devicetree
1442  *
1443  * DESCRIPTION:
1444  * This function is expensive and should only be used, if only one mode is to be
1445  * read from DT. To get multiple modes start with of_get_display_timings ond
1446  * work with that instead.
1447  */
of_get_fb_videomode(struct device_node * np,struct fb_videomode * fb,int index)1448 int of_get_fb_videomode(struct device_node *np, struct fb_videomode *fb,
1449 			int index)
1450 {
1451 	struct videomode vm;
1452 	int ret;
1453 
1454 	ret = of_get_videomode(np, &vm, index);
1455 	if (ret)
1456 		return ret;
1457 
1458 	fb_videomode_from_videomode(&vm, fb);
1459 
1460 	pr_debug("%s: got %dx%d display mode from %s\n",
1461 		of_node_full_name(np), vm.hactive, vm.vactive, np->name);
1462 	dump_fb_videomode(fb);
1463 
1464 	return 0;
1465 }
1466 EXPORT_SYMBOL_GPL(of_get_fb_videomode);
1467 #endif /* CONFIG_OF */
1468 #endif /* CONFIG_VIDEOMODE_HELPERS */
1469 
1470 #else
fb_parse_edid(unsigned char * edid,struct fb_var_screeninfo * var)1471 int fb_parse_edid(unsigned char *edid, struct fb_var_screeninfo *var)
1472 {
1473 	return 1;
1474 }
fb_edid_to_monspecs(unsigned char * edid,struct fb_monspecs * specs)1475 void fb_edid_to_monspecs(unsigned char *edid, struct fb_monspecs *specs)
1476 {
1477 	specs = NULL;
1478 }
fb_edid_add_monspecs(unsigned char * edid,struct fb_monspecs * specs)1479 void fb_edid_add_monspecs(unsigned char *edid, struct fb_monspecs *specs)
1480 {
1481 }
fb_destroy_modedb(struct fb_videomode * modedb)1482 void fb_destroy_modedb(struct fb_videomode *modedb)
1483 {
1484 }
fb_get_mode(int flags,u32 val,struct fb_var_screeninfo * var,struct fb_info * info)1485 int fb_get_mode(int flags, u32 val, struct fb_var_screeninfo *var,
1486 		struct fb_info *info)
1487 {
1488 	return -EINVAL;
1489 }
1490 #endif /* CONFIG_FB_MODE_HELPERS */
1491 
1492 /*
1493  * fb_validate_mode - validates var against monitor capabilities
1494  * @var: pointer to fb_var_screeninfo
1495  * @info: pointer to fb_info
1496  *
1497  * DESCRIPTION:
1498  * Validates video mode against monitor capabilities specified in
1499  * info->monspecs.
1500  *
1501  * REQUIRES:
1502  * A valid info->monspecs.
1503  */
fb_validate_mode(const struct fb_var_screeninfo * var,struct fb_info * info)1504 int fb_validate_mode(const struct fb_var_screeninfo *var, struct fb_info *info)
1505 {
1506 	u32 hfreq, vfreq, htotal, vtotal, pixclock;
1507 	u32 hfmin, hfmax, vfmin, vfmax, dclkmin, dclkmax;
1508 
1509 	/*
1510 	 * If monspecs are invalid, use values that are enough
1511 	 * for 640x480@60
1512 	 */
1513 	if (!info->monspecs.hfmax || !info->monspecs.vfmax ||
1514 	    !info->monspecs.dclkmax ||
1515 	    info->monspecs.hfmax < info->monspecs.hfmin ||
1516 	    info->monspecs.vfmax < info->monspecs.vfmin ||
1517 	    info->monspecs.dclkmax < info->monspecs.dclkmin) {
1518 		hfmin = 29000; hfmax = 30000;
1519 		vfmin = 60; vfmax = 60;
1520 		dclkmin = 0; dclkmax = 25000000;
1521 	} else {
1522 		hfmin = info->monspecs.hfmin;
1523 		hfmax = info->monspecs.hfmax;
1524 		vfmin = info->monspecs.vfmin;
1525 		vfmax = info->monspecs.vfmax;
1526 		dclkmin = info->monspecs.dclkmin;
1527 		dclkmax = info->monspecs.dclkmax;
1528 	}
1529 
1530 	if (!var->pixclock)
1531 		return -EINVAL;
1532 	pixclock = PICOS2KHZ(var->pixclock) * 1000;
1533 
1534 	htotal = var->xres + var->right_margin + var->hsync_len +
1535 		var->left_margin;
1536 	vtotal = var->yres + var->lower_margin + var->vsync_len +
1537 		var->upper_margin;
1538 
1539 	if (var->vmode & FB_VMODE_INTERLACED)
1540 		vtotal /= 2;
1541 	if (var->vmode & FB_VMODE_DOUBLE)
1542 		vtotal *= 2;
1543 
1544 	hfreq = pixclock/htotal;
1545 	hfreq = (hfreq + 500) / 1000 * 1000;
1546 
1547 	vfreq = hfreq/vtotal;
1548 
1549 	return (vfreq < vfmin || vfreq > vfmax ||
1550 		hfreq < hfmin || hfreq > hfmax ||
1551 		pixclock < dclkmin || pixclock > dclkmax) ?
1552 		-EINVAL : 0;
1553 }
1554 
1555 #if defined(CONFIG_FIRMWARE_EDID) && defined(CONFIG_X86)
1556 
1557 /*
1558  * We need to ensure that the EDID block is only returned for
1559  * the primary graphics adapter.
1560  */
1561 
fb_firmware_edid(struct device * device)1562 const unsigned char *fb_firmware_edid(struct device *device)
1563 {
1564 	struct pci_dev *dev = NULL;
1565 	struct resource *res = NULL;
1566 	unsigned char *edid = NULL;
1567 
1568 	if (device)
1569 		dev = to_pci_dev(device);
1570 
1571 	if (dev)
1572 		res = &dev->resource[PCI_ROM_RESOURCE];
1573 
1574 	if (res && res->flags & IORESOURCE_ROM_SHADOW)
1575 		edid = edid_info.dummy;
1576 
1577 	return edid;
1578 }
1579 #else
fb_firmware_edid(struct device * device)1580 const unsigned char *fb_firmware_edid(struct device *device)
1581 {
1582 	return NULL;
1583 }
1584 #endif
1585 EXPORT_SYMBOL(fb_firmware_edid);
1586 
1587 EXPORT_SYMBOL(fb_parse_edid);
1588 EXPORT_SYMBOL(fb_edid_to_monspecs);
1589 EXPORT_SYMBOL(fb_edid_add_monspecs);
1590 EXPORT_SYMBOL(fb_get_mode);
1591 EXPORT_SYMBOL(fb_validate_mode);
1592 EXPORT_SYMBOL(fb_destroy_modedb);
1593