xref: /linux/drivers/video/fbdev/core/fbmon.c (revision 06a88f47990974f1322c2bf2e8c5125f8a2f69fe)
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 https://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 
30 #include <linux/export.h>
31 #include <linux/fb.h>
32 #include <linux/module.h>
33 #include <linux/pci.h>
34 #include <linux/slab.h>
35 #include <video/edid.h>
36 #include <video/of_videomode.h>
37 #include <video/videomode.h>
38 #include "../edid.h"
39 #include <linux/string_choices.h>
40 
41 /*
42  * EDID parser
43  */
44 
45 #undef DEBUG  /* define this for verbose EDID parsing output */
46 
47 #ifdef DEBUG
48 #define DPRINTK(fmt, args...) printk(fmt,## args)
49 #else
50 #define DPRINTK(fmt, args...) no_printk(fmt, ##args)
51 #endif
52 
53 #define FBMON_FIX_HEADER  1
54 #define FBMON_FIX_INPUT   2
55 #define FBMON_FIX_TIMINGS 3
56 
57 #ifdef CONFIG_FB_MODE_HELPERS
58 struct broken_edid {
59 	u8  manufacturer[4];
60 	u32 model;
61 	u32 fix;
62 };
63 
64 static const struct broken_edid brokendb[] = {
65 	/* DEC FR-PCXAV-YZ */
66 	{
67 		.manufacturer = "DEC",
68 		.model        = 0x073a,
69 		.fix          = FBMON_FIX_HEADER,
70 	},
71 	/* ViewSonic PF775a */
72 	{
73 		.manufacturer = "VSC",
74 		.model        = 0x5a44,
75 		.fix          = FBMON_FIX_INPUT,
76 	},
77 	/* Sharp UXGA? */
78 	{
79 		.manufacturer = "SHP",
80 		.model        = 0x138e,
81 		.fix          = FBMON_FIX_TIMINGS,
82 	},
83 };
84 
85 static const unsigned char edid_v1_header[] = { 0x00, 0xff, 0xff, 0xff,
86 	0xff, 0xff, 0xff, 0x00
87 };
88 
copy_string(unsigned char * c,unsigned char * s)89 static void copy_string(unsigned char *c, unsigned char *s)
90 {
91   int i;
92   c = c + 5;
93   for (i = 0; (i < 13 && *c != 0x0A); i++)
94     *(s++) = *(c++);
95   *s = 0;
96   while (i-- && (*--s == 0x20)) *s = 0;
97 }
98 
edid_is_serial_block(unsigned char * block)99 static int edid_is_serial_block(unsigned char *block)
100 {
101 	if ((block[0] == 0x00) && (block[1] == 0x00) &&
102 	    (block[2] == 0x00) && (block[3] == 0xff) &&
103 	    (block[4] == 0x00))
104 		return 1;
105 	else
106 		return 0;
107 }
108 
edid_is_ascii_block(unsigned char * block)109 static int edid_is_ascii_block(unsigned char *block)
110 {
111 	if ((block[0] == 0x00) && (block[1] == 0x00) &&
112 	    (block[2] == 0x00) && (block[3] == 0xfe) &&
113 	    (block[4] == 0x00))
114 		return 1;
115 	else
116 		return 0;
117 }
118 
edid_is_limits_block(unsigned char * block)119 static int edid_is_limits_block(unsigned char *block)
120 {
121 	if ((block[0] == 0x00) && (block[1] == 0x00) &&
122 	    (block[2] == 0x00) && (block[3] == 0xfd) &&
123 	    (block[4] == 0x00))
124 		return 1;
125 	else
126 		return 0;
127 }
128 
edid_is_monitor_block(unsigned char * block)129 static int edid_is_monitor_block(unsigned char *block)
130 {
131 	if ((block[0] == 0x00) && (block[1] == 0x00) &&
132 	    (block[2] == 0x00) && (block[3] == 0xfc) &&
133 	    (block[4] == 0x00))
134 		return 1;
135 	else
136 		return 0;
137 }
138 
edid_is_timing_block(unsigned char * block)139 static int edid_is_timing_block(unsigned char *block)
140 {
141 	if ((block[0] != 0x00) || (block[1] != 0x00) ||
142 	    (block[2] != 0x00) || (block[4] != 0x00))
143 		return 1;
144 	else
145 		return 0;
146 }
147 
check_edid(unsigned char * edid)148 static int check_edid(unsigned char *edid)
149 {
150 	unsigned char *block = edid + ID_MANUFACTURER_NAME, manufacturer[4];
151 	unsigned char *b;
152 	u32 model;
153 	int i, fix = 0, ret = 0;
154 
155 	manufacturer[0] = ((block[0] & 0x7c) >> 2) + '@';
156 	manufacturer[1] = ((block[0] & 0x03) << 3) +
157 		((block[1] & 0xe0) >> 5) + '@';
158 	manufacturer[2] = (block[1] & 0x1f) + '@';
159 	manufacturer[3] = 0;
160 	model = block[2] + (block[3] << 8);
161 
162 	for (i = 0; i < ARRAY_SIZE(brokendb); i++) {
163 		if (!strncmp(manufacturer, brokendb[i].manufacturer, 4) &&
164 			brokendb[i].model == model) {
165 			fix = brokendb[i].fix;
166 			break;
167 		}
168 	}
169 
170 	switch (fix) {
171 	case FBMON_FIX_HEADER:
172 		for (i = 0; i < 8; i++) {
173 			if (edid[i] != edid_v1_header[i]) {
174 				ret = fix;
175 				break;
176 			}
177 		}
178 		break;
179 	case FBMON_FIX_INPUT:
180 		b = edid + EDID_STRUCT_DISPLAY;
181 		/* Only if display is GTF capable will
182 		   the input type be reset to analog */
183 		if (b[4] & 0x01 && b[0] & 0x80)
184 			ret = fix;
185 		break;
186 	case FBMON_FIX_TIMINGS:
187 		b = edid + DETAILED_TIMING_DESCRIPTIONS_START;
188 		ret = fix;
189 
190 		for (i = 0; i < 4; i++) {
191 			if (edid_is_limits_block(b)) {
192 				ret = 0;
193 				break;
194 			}
195 
196 			b += DETAILED_TIMING_DESCRIPTION_SIZE;
197 		}
198 
199 		break;
200 	}
201 
202 	if (ret)
203 		printk("fbmon: The EDID Block of "
204 		       "Manufacturer: %s Model: 0x%x is known to "
205 		       "be broken,\n",  manufacturer, model);
206 
207 	return ret;
208 }
209 
fix_edid(unsigned char * edid,int fix)210 static void fix_edid(unsigned char *edid, int fix)
211 {
212 	int i;
213 	unsigned char *b, csum = 0;
214 
215 	switch (fix) {
216 	case FBMON_FIX_HEADER:
217 		printk("fbmon: trying a header reconstruct\n");
218 		memcpy(edid, edid_v1_header, 8);
219 		break;
220 	case FBMON_FIX_INPUT:
221 		printk("fbmon: trying to fix input type\n");
222 		b = edid + EDID_STRUCT_DISPLAY;
223 		b[0] &= ~0x80;
224 		edid[127] += 0x80;
225 		break;
226 	case FBMON_FIX_TIMINGS:
227 		printk("fbmon: trying to fix monitor timings\n");
228 		b = edid + DETAILED_TIMING_DESCRIPTIONS_START;
229 		for (i = 0; i < 4; i++) {
230 			if (!(edid_is_serial_block(b) ||
231 			      edid_is_ascii_block(b) ||
232 			      edid_is_monitor_block(b) ||
233 			      edid_is_timing_block(b))) {
234 				b[0] = 0x00;
235 				b[1] = 0x00;
236 				b[2] = 0x00;
237 				b[3] = 0xfd;
238 				b[4] = 0x00;
239 				b[5] = 60;   /* vfmin */
240 				b[6] = 60;   /* vfmax */
241 				b[7] = 30;   /* hfmin */
242 				b[8] = 75;   /* hfmax */
243 				b[9] = 17;   /* pixclock - 170 MHz*/
244 				b[10] = 0;   /* GTF */
245 				break;
246 			}
247 
248 			b += DETAILED_TIMING_DESCRIPTION_SIZE;
249 		}
250 
251 		for (i = 0; i < EDID_LENGTH - 1; i++)
252 			csum += edid[i];
253 
254 		edid[127] = 256 - csum;
255 		break;
256 	}
257 }
258 
edid_checksum(unsigned char * edid)259 static int edid_checksum(unsigned char *edid)
260 {
261 	unsigned char csum = 0, all_null = 0;
262 	int i, err = 0, fix = check_edid(edid);
263 
264 	if (fix)
265 		fix_edid(edid, fix);
266 
267 	for (i = 0; i < EDID_LENGTH; i++) {
268 		csum += edid[i];
269 		all_null |= edid[i];
270 	}
271 
272 	if (csum == 0x00 && all_null) {
273 		/* checksum passed, everything's good */
274 		err = 1;
275 	}
276 
277 	return err;
278 }
279 
edid_check_header(unsigned char * edid)280 static int edid_check_header(unsigned char *edid)
281 {
282 	int i, err = 1, fix = check_edid(edid);
283 
284 	if (fix)
285 		fix_edid(edid, fix);
286 
287 	for (i = 0; i < 8; i++) {
288 		if (edid[i] != edid_v1_header[i])
289 			err = 0;
290 	}
291 
292 	return err;
293 }
294 
parse_vendor_block(unsigned char * block,struct fb_monspecs * specs)295 static void parse_vendor_block(unsigned char *block, struct fb_monspecs *specs)
296 {
297 	specs->manufacturer[0] = ((block[0] & 0x7c) >> 2) + '@';
298 	specs->manufacturer[1] = ((block[0] & 0x03) << 3) +
299 		((block[1] & 0xe0) >> 5) + '@';
300 	specs->manufacturer[2] = (block[1] & 0x1f) + '@';
301 	specs->manufacturer[3] = 0;
302 	specs->model = block[2] + (block[3] << 8);
303 	specs->serial = block[4] + (block[5] << 8) +
304 	       (block[6] << 16) + (block[7] << 24);
305 	specs->year = block[9] + 1990;
306 	specs->week = block[8];
307 	DPRINTK("   Manufacturer: %s\n", specs->manufacturer);
308 	DPRINTK("   Model: %x\n", specs->model);
309 	DPRINTK("   Serial#: %u\n", specs->serial);
310 	DPRINTK("   Year: %u Week %u\n", specs->year, specs->week);
311 }
312 
get_dpms_capabilities(unsigned char flags,struct fb_monspecs * specs)313 static void get_dpms_capabilities(unsigned char flags,
314 				  struct fb_monspecs *specs)
315 {
316 	specs->dpms = 0;
317 	if (flags & DPMS_ACTIVE_OFF)
318 		specs->dpms |= FB_DPMS_ACTIVE_OFF;
319 	if (flags & DPMS_SUSPEND)
320 		specs->dpms |= FB_DPMS_SUSPEND;
321 	if (flags & DPMS_STANDBY)
322 		specs->dpms |= FB_DPMS_STANDBY;
323 	DPRINTK("      DPMS: Active %s, Suspend %s, Standby %s\n",
324 	       str_yes_no(flags & DPMS_ACTIVE_OFF),
325 	       str_yes_no(flags & DPMS_SUSPEND),
326 	       str_yes_no(flags & DPMS_STANDBY));
327 }
328 
get_chroma(unsigned char * block,struct fb_monspecs * specs)329 static void get_chroma(unsigned char *block, struct fb_monspecs *specs)
330 {
331 	int tmp;
332 
333 	DPRINTK("      Chroma\n");
334 	/* Chromaticity data */
335 	tmp = ((block[5] & (3 << 6)) >> 6) | (block[0x7] << 2);
336 	tmp *= 1000;
337 	tmp += 512;
338 	specs->chroma.redx = tmp/1024;
339 	DPRINTK("         RedX:     0.%03d ", specs->chroma.redx);
340 
341 	tmp = ((block[5] & (3 << 4)) >> 4) | (block[0x8] << 2);
342 	tmp *= 1000;
343 	tmp += 512;
344 	specs->chroma.redy = tmp/1024;
345 	DPRINTK("RedY:     0.%03d\n", specs->chroma.redy);
346 
347 	tmp = ((block[5] & (3 << 2)) >> 2) | (block[0x9] << 2);
348 	tmp *= 1000;
349 	tmp += 512;
350 	specs->chroma.greenx = tmp/1024;
351 	DPRINTK("         GreenX:   0.%03d ", specs->chroma.greenx);
352 
353 	tmp = (block[5] & 3) | (block[0xa] << 2);
354 	tmp *= 1000;
355 	tmp += 512;
356 	specs->chroma.greeny = tmp/1024;
357 	DPRINTK("GreenY:   0.%03d\n", specs->chroma.greeny);
358 
359 	tmp = ((block[6] & (3 << 6)) >> 6) | (block[0xb] << 2);
360 	tmp *= 1000;
361 	tmp += 512;
362 	specs->chroma.bluex = tmp/1024;
363 	DPRINTK("         BlueX:    0.%03d ", specs->chroma.bluex);
364 
365 	tmp = ((block[6] & (3 << 4)) >> 4) | (block[0xc] << 2);
366 	tmp *= 1000;
367 	tmp += 512;
368 	specs->chroma.bluey = tmp/1024;
369 	DPRINTK("BlueY:    0.%03d\n", specs->chroma.bluey);
370 
371 	tmp = ((block[6] & (3 << 2)) >> 2) | (block[0xd] << 2);
372 	tmp *= 1000;
373 	tmp += 512;
374 	specs->chroma.whitex = tmp/1024;
375 	DPRINTK("         WhiteX:   0.%03d ", specs->chroma.whitex);
376 
377 	tmp = (block[6] & 3) | (block[0xe] << 2);
378 	tmp *= 1000;
379 	tmp += 512;
380 	specs->chroma.whitey = tmp/1024;
381 	DPRINTK("WhiteY:   0.%03d\n", specs->chroma.whitey);
382 }
383 
calc_mode_timings(int xres,int yres,int refresh,struct fb_videomode * mode)384 static void calc_mode_timings(int xres, int yres, int refresh,
385 			      struct fb_videomode *mode)
386 {
387 	struct fb_var_screeninfo *var;
388 
389 	var = kzalloc(sizeof(struct fb_var_screeninfo), GFP_KERNEL);
390 
391 	if (var) {
392 		var->xres = xres;
393 		var->yres = yres;
394 		fb_get_mode(FB_VSYNCTIMINGS | FB_IGNOREMON,
395 			    refresh, var, NULL);
396 		mode->xres = xres;
397 		mode->yres = yres;
398 		mode->pixclock = var->pixclock;
399 		mode->refresh = refresh;
400 		mode->left_margin = var->left_margin;
401 		mode->right_margin = var->right_margin;
402 		mode->upper_margin = var->upper_margin;
403 		mode->lower_margin = var->lower_margin;
404 		mode->hsync_len = var->hsync_len;
405 		mode->vsync_len = var->vsync_len;
406 		mode->vmode = 0;
407 		mode->sync = 0;
408 		kfree(var);
409 	}
410 }
411 
get_est_timing(unsigned char * block,struct fb_videomode * mode)412 static int get_est_timing(unsigned char *block, struct fb_videomode *mode)
413 {
414 	int num = 0;
415 	unsigned char c;
416 
417 	c = block[0];
418 	if (c&0x80) {
419 		calc_mode_timings(720, 400, 70, &mode[num]);
420 		mode[num++].flag = FB_MODE_IS_CALCULATED;
421 		DPRINTK("      720x400@70Hz\n");
422 	}
423 	if (c&0x40) {
424 		calc_mode_timings(720, 400, 88, &mode[num]);
425 		mode[num++].flag = FB_MODE_IS_CALCULATED;
426 		DPRINTK("      720x400@88Hz\n");
427 	}
428 	if (c&0x20) {
429 		mode[num++] = vesa_modes[3];
430 		DPRINTK("      640x480@60Hz\n");
431 	}
432 	if (c&0x10) {
433 		calc_mode_timings(640, 480, 67, &mode[num]);
434 		mode[num++].flag = FB_MODE_IS_CALCULATED;
435 		DPRINTK("      640x480@67Hz\n");
436 	}
437 	if (c&0x08) {
438 		mode[num++] = vesa_modes[4];
439 		DPRINTK("      640x480@72Hz\n");
440 	}
441 	if (c&0x04) {
442 		mode[num++] = vesa_modes[5];
443 		DPRINTK("      640x480@75Hz\n");
444 	}
445 	if (c&0x02) {
446 		mode[num++] = vesa_modes[7];
447 		DPRINTK("      800x600@56Hz\n");
448 	}
449 	if (c&0x01) {
450 		mode[num++] = vesa_modes[8];
451 		DPRINTK("      800x600@60Hz\n");
452 	}
453 
454 	c = block[1];
455 	if (c&0x80) {
456 		mode[num++] = vesa_modes[9];
457 		DPRINTK("      800x600@72Hz\n");
458 	}
459 	if (c&0x40) {
460 		mode[num++] = vesa_modes[10];
461 		DPRINTK("      800x600@75Hz\n");
462 	}
463 	if (c&0x20) {
464 		calc_mode_timings(832, 624, 75, &mode[num]);
465 		mode[num++].flag = FB_MODE_IS_CALCULATED;
466 		DPRINTK("      832x624@75Hz\n");
467 	}
468 	if (c&0x10) {
469 		mode[num++] = vesa_modes[12];
470 		DPRINTK("      1024x768@87Hz Interlaced\n");
471 	}
472 	if (c&0x08) {
473 		mode[num++] = vesa_modes[13];
474 		DPRINTK("      1024x768@60Hz\n");
475 	}
476 	if (c&0x04) {
477 		mode[num++] = vesa_modes[14];
478 		DPRINTK("      1024x768@70Hz\n");
479 	}
480 	if (c&0x02) {
481 		mode[num++] = vesa_modes[15];
482 		DPRINTK("      1024x768@75Hz\n");
483 	}
484 	if (c&0x01) {
485 		mode[num++] = vesa_modes[21];
486 		DPRINTK("      1280x1024@75Hz\n");
487 	}
488 	c = block[2];
489 	if (c&0x80) {
490 		mode[num++] = vesa_modes[17];
491 		DPRINTK("      1152x870@75Hz\n");
492 	}
493 	DPRINTK("      Manufacturer's mask: %x\n",c&0x7F);
494 	return num;
495 }
496 
get_std_timing(unsigned char * block,struct fb_videomode * mode,int ver,int rev,const struct fb_monspecs * specs)497 static int get_std_timing(unsigned char *block, struct fb_videomode *mode,
498 			  int ver, int rev, const struct fb_monspecs *specs)
499 {
500 	int i;
501 
502 	for (i = 0; i < DMT_SIZE; i++) {
503 		u32 std_2byte_code = block[0] << 8 | block[1];
504 		if (std_2byte_code == dmt_modes[i].std_2byte_code)
505 			break;
506 	}
507 
508 	if (i < DMT_SIZE && dmt_modes[i].mode) {
509 		/* DMT mode found */
510 		*mode = *dmt_modes[i].mode;
511 		mode->flag |= FB_MODE_IS_STANDARD;
512 		DPRINTK("        DMT id=%d\n", dmt_modes[i].dmt_id);
513 
514 	} else {
515 		int xres, yres = 0, refresh, ratio;
516 
517 		xres = (block[0] + 31) * 8;
518 		if (xres <= 256)
519 			return 0;
520 
521 		ratio = (block[1] & 0xc0) >> 6;
522 		switch (ratio) {
523 		case 0:
524 			/* in EDID 1.3 the meaning of 0 changed to 16:10 (prior 1:1) */
525 			if (ver < 1 || (ver == 1 && rev < 3))
526 				yres = xres;
527 			else
528 				yres = (xres * 10)/16;
529 			break;
530 		case 1:
531 			yres = (xres * 3)/4;
532 			break;
533 		case 2:
534 			yres = (xres * 4)/5;
535 			break;
536 		case 3:
537 			yres = (xres * 9)/16;
538 			break;
539 		}
540 		refresh = (block[1] & 0x3f) + 60;
541 		DPRINTK("      %dx%d@%dHz\n", xres, yres, refresh);
542 
543 		calc_mode_timings(xres, yres, refresh, mode);
544 	}
545 
546 	/* Check the mode we got is within valid spec of the monitor */
547 	if (specs && specs->dclkmax
548 	    && PICOS2KHZ(mode->pixclock) * 1000 > specs->dclkmax) {
549 		DPRINTK("        mode exceed max DCLK\n");
550 		return 0;
551 	}
552 
553 	return 1;
554 }
555 
get_dst_timing(unsigned char * block,struct fb_videomode * mode,int ver,int rev,const struct fb_monspecs * specs)556 static int get_dst_timing(unsigned char *block, struct fb_videomode *mode,
557 			  int ver, int rev, const struct fb_monspecs *specs)
558 {
559 	int j, num = 0;
560 
561 	for (j = 0; j < 6; j++, block += STD_TIMING_DESCRIPTION_SIZE)
562 		num += get_std_timing(block, &mode[num], ver, rev, specs);
563 
564 	return num;
565 }
566 
get_detailed_timing(unsigned char * block,struct fb_videomode * mode)567 static void get_detailed_timing(unsigned char *block,
568 				struct fb_videomode *mode)
569 {
570 	mode->xres = H_ACTIVE;
571 	mode->yres = V_ACTIVE;
572 	mode->pixclock = PIXEL_CLOCK;
573 	mode->pixclock /= 1000;
574 	mode->pixclock = KHZ2PICOS(mode->pixclock);
575 	mode->right_margin = H_SYNC_OFFSET;
576 	mode->left_margin = (H_ACTIVE + H_BLANKING) -
577 		(H_ACTIVE + H_SYNC_OFFSET + H_SYNC_WIDTH);
578 	mode->upper_margin = V_BLANKING - V_SYNC_OFFSET -
579 		V_SYNC_WIDTH;
580 	mode->lower_margin = V_SYNC_OFFSET;
581 	mode->hsync_len = H_SYNC_WIDTH;
582 	mode->vsync_len = V_SYNC_WIDTH;
583 	if (HSYNC_POSITIVE)
584 		mode->sync |= FB_SYNC_HOR_HIGH_ACT;
585 	if (VSYNC_POSITIVE)
586 		mode->sync |= FB_SYNC_VERT_HIGH_ACT;
587 	mode->refresh = PIXEL_CLOCK/((H_ACTIVE + H_BLANKING) *
588 				     (V_ACTIVE + V_BLANKING));
589 	if (INTERLACED) {
590 		mode->yres *= 2;
591 		mode->upper_margin *= 2;
592 		mode->lower_margin *= 2;
593 		mode->vsync_len *= 2;
594 		mode->vmode |= FB_VMODE_INTERLACED;
595 	}
596 	mode->flag = FB_MODE_IS_DETAILED;
597 
598 	DPRINTK("      %d MHz ",  PIXEL_CLOCK/1000000);
599 	DPRINTK("%d %d %d %d ", H_ACTIVE, H_ACTIVE + H_SYNC_OFFSET,
600 	       H_ACTIVE + H_SYNC_OFFSET + H_SYNC_WIDTH, H_ACTIVE + H_BLANKING);
601 	DPRINTK("%d %d %d %d ", V_ACTIVE, V_ACTIVE + V_SYNC_OFFSET,
602 	       V_ACTIVE + V_SYNC_OFFSET + V_SYNC_WIDTH, V_ACTIVE + V_BLANKING);
603 	DPRINTK("%sHSync %sVSync\n\n", (HSYNC_POSITIVE) ? "+" : "-",
604 	       (VSYNC_POSITIVE) ? "+" : "-");
605 }
606 
607 /**
608  * fb_create_modedb - create video mode database
609  * @edid: EDID data
610  * @dbsize: database size
611  * @specs: monitor specifications, may be NULL
612  *
613  * RETURNS: struct fb_videomode, @dbsize contains length of database
614  *
615  * DESCRIPTION:
616  * This function builds a mode database using the contents of the EDID
617  * data
618  */
fb_create_modedb(unsigned char * edid,int * dbsize,const struct fb_monspecs * specs)619 static struct fb_videomode *fb_create_modedb(unsigned char *edid, int *dbsize,
620 					     const struct fb_monspecs *specs)
621 {
622 	struct fb_videomode *mode, *m;
623 	unsigned char *block;
624 	int num = 0, i, first = 1;
625 	int ver, rev;
626 
627 	mode = kcalloc(50, sizeof(struct fb_videomode), GFP_KERNEL);
628 	if (mode == NULL)
629 		return NULL;
630 
631 	if (edid == NULL || !edid_checksum(edid) ||
632 	    !edid_check_header(edid)) {
633 		kfree(mode);
634 		return NULL;
635 	}
636 
637 	ver = edid[EDID_STRUCT_VERSION];
638 	rev = edid[EDID_STRUCT_REVISION];
639 
640 	*dbsize = 0;
641 
642 	DPRINTK("   Detailed Timings\n");
643 	block = edid + DETAILED_TIMING_DESCRIPTIONS_START;
644 	for (i = 0; i < 4; i++, block+= DETAILED_TIMING_DESCRIPTION_SIZE) {
645 		if (!(block[0] == 0x00 && block[1] == 0x00)) {
646 			get_detailed_timing(block, &mode[num]);
647 			if (first) {
648 			        mode[num].flag |= FB_MODE_IS_FIRST;
649 				first = 0;
650 			}
651 			num++;
652 		}
653 	}
654 
655 	DPRINTK("   Supported VESA Modes\n");
656 	block = edid + ESTABLISHED_TIMING_1;
657 	num += get_est_timing(block, &mode[num]);
658 
659 	DPRINTK("   Standard Timings\n");
660 	block = edid + STD_TIMING_DESCRIPTIONS_START;
661 	for (i = 0; i < STD_TIMING; i++, block += STD_TIMING_DESCRIPTION_SIZE)
662 		num += get_std_timing(block, &mode[num], ver, rev, specs);
663 
664 	block = edid + DETAILED_TIMING_DESCRIPTIONS_START;
665 	for (i = 0; i < 4; i++, block+= DETAILED_TIMING_DESCRIPTION_SIZE) {
666 		if (block[0] == 0x00 && block[1] == 0x00 && block[3] == 0xfa)
667 			num += get_dst_timing(block + 5, &mode[num],
668 					      ver, rev, specs);
669 	}
670 
671 	/* Yikes, EDID data is totally useless */
672 	if (!num) {
673 		kfree(mode);
674 		return NULL;
675 	}
676 
677 	*dbsize = num;
678 	m = kmalloc_array(num, sizeof(struct fb_videomode), GFP_KERNEL);
679 	if (!m)
680 		return mode;
681 	memmove(m, mode, num * sizeof(struct fb_videomode));
682 	kfree(mode);
683 	return m;
684 }
685 
686 /**
687  * fb_destroy_modedb - destroys mode database
688  * @modedb: mode database to destroy
689  *
690  * DESCRIPTION:
691  * Destroy mode database created by fb_create_modedb
692  */
fb_destroy_modedb(struct fb_videomode * modedb)693 void fb_destroy_modedb(struct fb_videomode *modedb)
694 {
695 	kfree(modedb);
696 }
697 
fb_get_monitor_limits(unsigned char * edid,struct fb_monspecs * specs)698 static int fb_get_monitor_limits(unsigned char *edid, struct fb_monspecs *specs)
699 {
700 	int i, retval = 1;
701 	unsigned char *block;
702 
703 	block = edid + DETAILED_TIMING_DESCRIPTIONS_START;
704 
705 	DPRINTK("      Monitor Operating Limits: ");
706 
707 	for (i = 0; i < 4; i++, block += DETAILED_TIMING_DESCRIPTION_SIZE) {
708 		if (edid_is_limits_block(block)) {
709 			specs->hfmin = H_MIN_RATE * 1000;
710 			specs->hfmax = H_MAX_RATE * 1000;
711 			specs->vfmin = V_MIN_RATE;
712 			specs->vfmax = V_MAX_RATE;
713 			specs->dclkmax = MAX_PIXEL_CLOCK * 1000000;
714 			specs->gtf = (GTF_SUPPORT) ? 1 : 0;
715 			retval = 0;
716 			DPRINTK("From EDID\n");
717 			break;
718 		}
719 	}
720 
721 	/* estimate monitor limits based on modes supported */
722 	if (retval) {
723 		struct fb_videomode *modes, *mode;
724 		int num_modes, hz, hscan, pixclock;
725 		int vtotal, htotal;
726 
727 		modes = fb_create_modedb(edid, &num_modes, specs);
728 		if (!modes) {
729 			DPRINTK("None Available\n");
730 			return 1;
731 		}
732 
733 		retval = 0;
734 		for (i = 0; i < num_modes; i++) {
735 			mode = &modes[i];
736 			pixclock = PICOS2KHZ(modes[i].pixclock) * 1000;
737 			htotal = mode->xres + mode->right_margin + mode->hsync_len
738 				+ mode->left_margin;
739 			vtotal = mode->yres + mode->lower_margin + mode->vsync_len
740 				+ mode->upper_margin;
741 
742 			if (mode->vmode & FB_VMODE_INTERLACED)
743 				vtotal /= 2;
744 
745 			if (mode->vmode & FB_VMODE_DOUBLE)
746 				vtotal *= 2;
747 
748 			hscan = (pixclock + htotal / 2) / htotal;
749 			hscan = (hscan + 500) / 1000 * 1000;
750 			hz = (hscan + vtotal / 2) / vtotal;
751 
752 			if (specs->dclkmax == 0 || specs->dclkmax < pixclock)
753 				specs->dclkmax = pixclock;
754 
755 			if (specs->dclkmin == 0 || specs->dclkmin > pixclock)
756 				specs->dclkmin = pixclock;
757 
758 			if (specs->hfmax == 0 || specs->hfmax < hscan)
759 				specs->hfmax = hscan;
760 
761 			if (specs->hfmin == 0 || specs->hfmin > hscan)
762 				specs->hfmin = hscan;
763 
764 			if (specs->vfmax == 0 || specs->vfmax < hz)
765 				specs->vfmax = hz;
766 
767 			if (specs->vfmin == 0 || specs->vfmin > hz)
768 				specs->vfmin = hz;
769 		}
770 		DPRINTK("Extrapolated\n");
771 		fb_destroy_modedb(modes);
772 	}
773 	DPRINTK("           H: %d-%dKHz V: %d-%dHz DCLK: %dMHz\n",
774 		specs->hfmin/1000, specs->hfmax/1000, specs->vfmin,
775 		specs->vfmax, specs->dclkmax/1000000);
776 	return retval;
777 }
778 
get_monspecs(unsigned char * edid,struct fb_monspecs * specs)779 static void get_monspecs(unsigned char *edid, struct fb_monspecs *specs)
780 {
781 	unsigned char c, *block;
782 
783 	block = edid + EDID_STRUCT_DISPLAY;
784 
785 	fb_get_monitor_limits(edid, specs);
786 
787 	c = block[0] & 0x80;
788 	specs->input = 0;
789 	if (c) {
790 		specs->input |= FB_DISP_DDI;
791 		DPRINTK("      Digital Display Input");
792 	} else {
793 		DPRINTK("      Analog Display Input: Input Voltage - ");
794 		switch ((block[0] & 0x60) >> 5) {
795 		case 0:
796 			DPRINTK("0.700V/0.300V");
797 			specs->input |= FB_DISP_ANA_700_300;
798 			break;
799 		case 1:
800 			DPRINTK("0.714V/0.286V");
801 			specs->input |= FB_DISP_ANA_714_286;
802 			break;
803 		case 2:
804 			DPRINTK("1.000V/0.400V");
805 			specs->input |= FB_DISP_ANA_1000_400;
806 			break;
807 		case 3:
808 			DPRINTK("0.700V/0.000V");
809 			specs->input |= FB_DISP_ANA_700_000;
810 			break;
811 		}
812 	}
813 	DPRINTK("\n      Sync: ");
814 	c = block[0] & 0x10;
815 	if (c)
816 		DPRINTK("      Configurable signal level\n");
817 	c = block[0] & 0x0f;
818 	specs->signal = 0;
819 	if (c & 0x10) {
820 		DPRINTK("Blank to Blank ");
821 		specs->signal |= FB_SIGNAL_BLANK_BLANK;
822 	}
823 	if (c & 0x08) {
824 		DPRINTK("Separate ");
825 		specs->signal |= FB_SIGNAL_SEPARATE;
826 	}
827 	if (c & 0x04) {
828 		DPRINTK("Composite ");
829 		specs->signal |= FB_SIGNAL_COMPOSITE;
830 	}
831 	if (c & 0x02) {
832 		DPRINTK("Sync on Green ");
833 		specs->signal |= FB_SIGNAL_SYNC_ON_GREEN;
834 	}
835 	if (c & 0x01) {
836 		DPRINTK("Serration on ");
837 		specs->signal |= FB_SIGNAL_SERRATION_ON;
838 	}
839 	DPRINTK("\n");
840 	specs->max_x = block[1];
841 	specs->max_y = block[2];
842 	DPRINTK("      Max H-size in cm: ");
843 	if (specs->max_x)
844 		DPRINTK("%d\n", specs->max_x);
845 	else
846 		DPRINTK("variable\n");
847 	DPRINTK("      Max V-size in cm: ");
848 	if (specs->max_y)
849 		DPRINTK("%d\n", specs->max_y);
850 	else
851 		DPRINTK("variable\n");
852 
853 	c = block[3];
854 	specs->gamma = c+100;
855 	DPRINTK("      Gamma: ");
856 	DPRINTK("%d.%d\n", specs->gamma/100, specs->gamma % 100);
857 
858 	get_dpms_capabilities(block[4], specs);
859 
860 	switch ((block[4] & 0x18) >> 3) {
861 	case 0:
862 		DPRINTK("      Monochrome/Grayscale\n");
863 		specs->input |= FB_DISP_MONO;
864 		break;
865 	case 1:
866 		DPRINTK("      RGB Color Display\n");
867 		specs->input |= FB_DISP_RGB;
868 		break;
869 	case 2:
870 		DPRINTK("      Non-RGB Multicolor Display\n");
871 		specs->input |= FB_DISP_MULTI;
872 		break;
873 	default:
874 		DPRINTK("      Unknown\n");
875 		specs->input |= FB_DISP_UNKNOWN;
876 		break;
877 	}
878 
879 	get_chroma(block, specs);
880 
881 	specs->misc = 0;
882 	c = block[4] & 0x7;
883 	if (c & 0x04) {
884 		DPRINTK("      Default color format is primary\n");
885 		specs->misc |= FB_MISC_PRIM_COLOR;
886 	}
887 	if (c & 0x02) {
888 		DPRINTK("      First DETAILED Timing is preferred\n");
889 		specs->misc |= FB_MISC_1ST_DETAIL;
890 	}
891 	if (c & 0x01) {
892 		printk("      Display is GTF capable\n");
893 		specs->gtf = 1;
894 	}
895 }
896 
fb_parse_edid(unsigned char * edid,struct fb_var_screeninfo * var)897 int fb_parse_edid(unsigned char *edid, struct fb_var_screeninfo *var)
898 {
899 	int i;
900 	unsigned char *block;
901 
902 	if (edid == NULL || var == NULL)
903 		return 1;
904 
905 	if (!(edid_checksum(edid)))
906 		return 1;
907 
908 	if (!(edid_check_header(edid)))
909 		return 1;
910 
911 	block = edid + DETAILED_TIMING_DESCRIPTIONS_START;
912 
913 	for (i = 0; i < 4; i++, block += DETAILED_TIMING_DESCRIPTION_SIZE) {
914 		if (edid_is_timing_block(block)) {
915 			var->xres = var->xres_virtual = H_ACTIVE;
916 			var->yres = var->yres_virtual = V_ACTIVE;
917 			var->height = var->width = 0;
918 			var->right_margin = H_SYNC_OFFSET;
919 			var->left_margin = (H_ACTIVE + H_BLANKING) -
920 				(H_ACTIVE + H_SYNC_OFFSET + H_SYNC_WIDTH);
921 			var->upper_margin = V_BLANKING - V_SYNC_OFFSET -
922 				V_SYNC_WIDTH;
923 			var->lower_margin = V_SYNC_OFFSET;
924 			var->hsync_len = H_SYNC_WIDTH;
925 			var->vsync_len = V_SYNC_WIDTH;
926 			var->pixclock = PIXEL_CLOCK;
927 			var->pixclock /= 1000;
928 			var->pixclock = KHZ2PICOS(var->pixclock);
929 
930 			if (HSYNC_POSITIVE)
931 				var->sync |= FB_SYNC_HOR_HIGH_ACT;
932 			if (VSYNC_POSITIVE)
933 				var->sync |= FB_SYNC_VERT_HIGH_ACT;
934 			return 0;
935 		}
936 	}
937 	return 1;
938 }
939 
fb_edid_to_monspecs(unsigned char * edid,struct fb_monspecs * specs)940 void fb_edid_to_monspecs(unsigned char *edid, struct fb_monspecs *specs)
941 {
942 	unsigned char *block;
943 	int i, found = 0;
944 
945 	if (edid == NULL)
946 		return;
947 
948 	if (!(edid_checksum(edid)))
949 		return;
950 
951 	if (!(edid_check_header(edid)))
952 		return;
953 
954 	memset(specs, 0, sizeof(struct fb_monspecs));
955 
956 	specs->version = edid[EDID_STRUCT_VERSION];
957 	specs->revision = edid[EDID_STRUCT_REVISION];
958 
959 	DPRINTK("========================================\n");
960 	DPRINTK("Display Information (EDID)\n");
961 	DPRINTK("========================================\n");
962 	DPRINTK("   EDID Version %d.%d\n", (int) specs->version,
963 	       (int) specs->revision);
964 
965 	parse_vendor_block(edid + ID_MANUFACTURER_NAME, specs);
966 
967 	block = edid + DETAILED_TIMING_DESCRIPTIONS_START;
968 	for (i = 0; i < 4; i++, block += DETAILED_TIMING_DESCRIPTION_SIZE) {
969 		if (edid_is_serial_block(block)) {
970 			copy_string(block, specs->serial_no);
971 			DPRINTK("   Serial Number: %s\n", specs->serial_no);
972 		} else if (edid_is_ascii_block(block)) {
973 			copy_string(block, specs->ascii);
974 			DPRINTK("   ASCII Block: %s\n", specs->ascii);
975 		} else if (edid_is_monitor_block(block)) {
976 			copy_string(block, specs->monitor);
977 			DPRINTK("   Monitor Name: %s\n", specs->monitor);
978 		}
979 	}
980 
981 	DPRINTK("   Display Characteristics:\n");
982 	get_monspecs(edid, specs);
983 
984 	specs->modedb = fb_create_modedb(edid, &specs->modedb_len, specs);
985 	if (!specs->modedb)
986 		return;
987 
988 	/*
989 	 * Workaround for buggy EDIDs that sets that the first
990 	 * detailed timing is preferred but has not detailed
991 	 * timing specified
992 	 */
993 	for (i = 0; i < specs->modedb_len; i++) {
994 		if (specs->modedb[i].flag & FB_MODE_IS_DETAILED) {
995 			found = 1;
996 			break;
997 		}
998 	}
999 
1000 	if (!found)
1001 		specs->misc &= ~FB_MISC_1ST_DETAIL;
1002 
1003 	DPRINTK("========================================\n");
1004 }
1005 
1006 /*
1007  * VESA Generalized Timing Formula (GTF)
1008  */
1009 
1010 #define FLYBACK                     550
1011 #define V_FRONTPORCH                1
1012 #define H_OFFSET                    40
1013 #define H_SCALEFACTOR               20
1014 #define H_BLANKSCALE                128
1015 #define H_GRADIENT                  600
1016 #define C_VAL                       30
1017 #define M_VAL                       300
1018 
1019 struct __fb_timings {
1020 	u32 dclk;
1021 	u32 hfreq;
1022 	u32 vfreq;
1023 	u32 hactive;
1024 	u32 vactive;
1025 	u32 hblank;
1026 	u32 vblank;
1027 	u32 htotal;
1028 	u32 vtotal;
1029 };
1030 
1031 /**
1032  * fb_get_vblank - get vertical blank time
1033  * @hfreq: horizontal freq
1034  *
1035  * DESCRIPTION:
1036  * vblank = right_margin + vsync_len + left_margin
1037  *
1038  *    given: right_margin = 1 (V_FRONTPORCH)
1039  *           vsync_len    = 3
1040  *           flyback      = 550
1041  *
1042  *                          flyback * hfreq
1043  *           left_margin  = --------------- - vsync_len
1044  *                           1000000
1045  */
fb_get_vblank(u32 hfreq)1046 static u32 fb_get_vblank(u32 hfreq)
1047 {
1048 	u32 vblank;
1049 
1050 	vblank = (hfreq * FLYBACK)/1000;
1051 	vblank = (vblank + 500)/1000;
1052 	return (vblank + V_FRONTPORCH);
1053 }
1054 
1055 /**
1056  * fb_get_hblank_by_hfreq - get horizontal blank time given hfreq
1057  * @hfreq: horizontal freq
1058  * @xres: horizontal resolution in pixels
1059  *
1060  * DESCRIPTION:
1061  *
1062  *           xres * duty_cycle
1063  * hblank = ------------------
1064  *           100 - duty_cycle
1065  *
1066  * duty cycle = percent of htotal assigned to inactive display
1067  * duty cycle = C - (M/Hfreq)
1068  *
1069  * where: C = ((offset - scale factor) * blank_scale)
1070  *            -------------------------------------- + scale factor
1071  *                        256
1072  *        M = blank_scale * gradient
1073  *
1074  */
fb_get_hblank_by_hfreq(u32 hfreq,u32 xres)1075 static u32 fb_get_hblank_by_hfreq(u32 hfreq, u32 xres)
1076 {
1077 	u32 c_val, m_val, duty_cycle, hblank;
1078 
1079 	c_val = (((H_OFFSET - H_SCALEFACTOR) * H_BLANKSCALE)/256 +
1080 		 H_SCALEFACTOR) * 1000;
1081 	m_val = (H_BLANKSCALE * H_GRADIENT)/256;
1082 	m_val = (m_val * 1000000)/hfreq;
1083 	duty_cycle = c_val - m_val;
1084 	hblank = (xres * duty_cycle)/(100000 - duty_cycle);
1085 	return (hblank);
1086 }
1087 
1088 /**
1089  * fb_get_hblank_by_dclk - get horizontal blank time given pixelclock
1090  * @dclk: pixelclock in Hz
1091  * @xres: horizontal resolution in pixels
1092  *
1093  * DESCRIPTION:
1094  *
1095  *           xres * duty_cycle
1096  * hblank = ------------------
1097  *           100 - duty_cycle
1098  *
1099  * duty cycle = percent of htotal assigned to inactive display
1100  * duty cycle = C - (M * h_period)
1101  *
1102  * where: h_period = SQRT(100 - C + (0.4 * xres * M)/dclk) + C - 100
1103  *                   -----------------------------------------------
1104  *                                    2 * M
1105  *        M = 300;
1106  *        C = 30;
1107  */
fb_get_hblank_by_dclk(u32 dclk,u32 xres)1108 static u32 fb_get_hblank_by_dclk(u32 dclk, u32 xres)
1109 {
1110 	u32 duty_cycle, h_period, hblank;
1111 
1112 	dclk /= 1000;
1113 	h_period = 100 - C_VAL;
1114 	h_period *= h_period;
1115 	h_period += (M_VAL * xres * 2 * 1000)/(5 * dclk);
1116 	h_period *= 10000;
1117 
1118 	h_period = int_sqrt(h_period);
1119 	h_period -= (100 - C_VAL) * 100;
1120 	h_period *= 1000;
1121 	h_period /= 2 * M_VAL;
1122 
1123 	duty_cycle = C_VAL * 1000 - (M_VAL * h_period)/100;
1124 	hblank = (xres * duty_cycle)/(100000 - duty_cycle) + 8;
1125 	hblank &= ~15;
1126 	return (hblank);
1127 }
1128 
1129 /**
1130  * fb_get_hfreq - estimate hsync
1131  * @vfreq: vertical refresh rate
1132  * @yres: vertical resolution
1133  *
1134  * DESCRIPTION:
1135  *
1136  *          (yres + front_port) * vfreq * 1000000
1137  * hfreq = -------------------------------------
1138  *          (1000000 - (vfreq * FLYBACK)
1139  *
1140  */
1141 
fb_get_hfreq(u32 vfreq,u32 yres)1142 static u32 fb_get_hfreq(u32 vfreq, u32 yres)
1143 {
1144 	u32 divisor, hfreq;
1145 
1146 	divisor = (1000000 - (vfreq * FLYBACK))/1000;
1147 	hfreq = (yres + V_FRONTPORCH) * vfreq  * 1000;
1148 	return (hfreq/divisor);
1149 }
1150 
fb_timings_vfreq(struct __fb_timings * timings)1151 static void fb_timings_vfreq(struct __fb_timings *timings)
1152 {
1153 	timings->hfreq = fb_get_hfreq(timings->vfreq, timings->vactive);
1154 	timings->vblank = fb_get_vblank(timings->hfreq);
1155 	timings->vtotal = timings->vactive + timings->vblank;
1156 	timings->hblank = fb_get_hblank_by_hfreq(timings->hfreq,
1157 						 timings->hactive);
1158 	timings->htotal = timings->hactive + timings->hblank;
1159 	timings->dclk = timings->htotal * timings->hfreq;
1160 }
1161 
fb_timings_hfreq(struct __fb_timings * timings)1162 static void fb_timings_hfreq(struct __fb_timings *timings)
1163 {
1164 	timings->vblank = fb_get_vblank(timings->hfreq);
1165 	timings->vtotal = timings->vactive + timings->vblank;
1166 	timings->vfreq = timings->hfreq/timings->vtotal;
1167 	timings->hblank = fb_get_hblank_by_hfreq(timings->hfreq,
1168 						 timings->hactive);
1169 	timings->htotal = timings->hactive + timings->hblank;
1170 	timings->dclk = timings->htotal * timings->hfreq;
1171 }
1172 
fb_timings_dclk(struct __fb_timings * timings)1173 static void fb_timings_dclk(struct __fb_timings *timings)
1174 {
1175 	timings->hblank = fb_get_hblank_by_dclk(timings->dclk,
1176 						timings->hactive);
1177 	timings->htotal = timings->hactive + timings->hblank;
1178 	timings->hfreq = timings->dclk/timings->htotal;
1179 	timings->vblank = fb_get_vblank(timings->hfreq);
1180 	timings->vtotal = timings->vactive + timings->vblank;
1181 	timings->vfreq = timings->hfreq/timings->vtotal;
1182 }
1183 
1184 /*
1185  * fb_get_mode - calculates video mode using VESA GTF
1186  * @flags: if: 0 - maximize vertical refresh rate
1187  *             1 - vrefresh-driven calculation;
1188  *             2 - hscan-driven calculation;
1189  *             3 - pixelclock-driven calculation;
1190  * @val: depending on @flags, ignored, vrefresh, hsync or pixelclock
1191  * @var: pointer to fb_var_screeninfo
1192  * @info: pointer to fb_info
1193  *
1194  * DESCRIPTION:
1195  * Calculates video mode based on monitor specs using VESA GTF.
1196  * The GTF is best for VESA GTF compliant monitors but is
1197  * specifically formulated to work for older monitors as well.
1198  *
1199  * If @flag==0, the function will attempt to maximize the
1200  * refresh rate.  Otherwise, it will calculate timings based on
1201  * the flag and accompanying value.
1202  *
1203  * If FB_IGNOREMON bit is set in @flags, monitor specs will be
1204  * ignored and @var will be filled with the calculated timings.
1205  *
1206  * All calculations are based on the VESA GTF Spreadsheet
1207  * available at VESA's public ftp (https://www.vesa.org).
1208  *
1209  * NOTES:
1210  * The timings generated by the GTF will be different from VESA
1211  * DMT.  It might be a good idea to keep a table of standard
1212  * VESA modes as well.  The GTF may also not work for some displays,
1213  * such as, and especially, analog TV.
1214  *
1215  * REQUIRES:
1216  * A valid info->monspecs, otherwise 'safe numbers' will be used.
1217  */
fb_get_mode(int flags,u32 val,struct fb_var_screeninfo * var,struct fb_info * info)1218 int fb_get_mode(int flags, u32 val, struct fb_var_screeninfo *var, struct fb_info *info)
1219 {
1220 	struct __fb_timings *timings;
1221 	u32 interlace = 1, dscan = 1;
1222 	u32 hfmin, hfmax, vfmin, vfmax, dclkmin, dclkmax, err = 0;
1223 
1224 
1225 	timings = kzalloc(sizeof(struct __fb_timings), GFP_KERNEL);
1226 
1227 	if (!timings)
1228 		return -ENOMEM;
1229 
1230 	/*
1231 	 * If monspecs are invalid, use values that are enough
1232 	 * for 640x480@60
1233 	 */
1234 	if (!info || !info->monspecs.hfmax || !info->monspecs.vfmax ||
1235 	    !info->monspecs.dclkmax ||
1236 	    info->monspecs.hfmax < info->monspecs.hfmin ||
1237 	    info->monspecs.vfmax < info->monspecs.vfmin ||
1238 	    info->monspecs.dclkmax < info->monspecs.dclkmin) {
1239 		hfmin = 29000; hfmax = 30000;
1240 		vfmin = 60; vfmax = 60;
1241 		dclkmin = 0; dclkmax = 25000000;
1242 	} else {
1243 		hfmin = info->monspecs.hfmin;
1244 		hfmax = info->monspecs.hfmax;
1245 		vfmin = info->monspecs.vfmin;
1246 		vfmax = info->monspecs.vfmax;
1247 		dclkmin = info->monspecs.dclkmin;
1248 		dclkmax = info->monspecs.dclkmax;
1249 	}
1250 
1251 	timings->hactive = var->xres;
1252 	timings->vactive = var->yres;
1253 	if (var->vmode & FB_VMODE_INTERLACED) {
1254 		timings->vactive /= 2;
1255 		interlace = 2;
1256 	}
1257 	if (var->vmode & FB_VMODE_DOUBLE) {
1258 		timings->vactive *= 2;
1259 		dscan = 2;
1260 	}
1261 
1262 	switch (flags & ~FB_IGNOREMON) {
1263 	case FB_MAXTIMINGS: /* maximize refresh rate */
1264 		timings->hfreq = hfmax;
1265 		fb_timings_hfreq(timings);
1266 		if (timings->vfreq > vfmax) {
1267 			timings->vfreq = vfmax;
1268 			fb_timings_vfreq(timings);
1269 		}
1270 		if (timings->dclk > dclkmax) {
1271 			timings->dclk = dclkmax;
1272 			fb_timings_dclk(timings);
1273 		}
1274 		break;
1275 	case FB_VSYNCTIMINGS: /* vrefresh driven */
1276 		timings->vfreq = val;
1277 		fb_timings_vfreq(timings);
1278 		break;
1279 	case FB_HSYNCTIMINGS: /* hsync driven */
1280 		timings->hfreq = val;
1281 		fb_timings_hfreq(timings);
1282 		break;
1283 	case FB_DCLKTIMINGS: /* pixelclock driven */
1284 		timings->dclk = PICOS2KHZ(val) * 1000;
1285 		fb_timings_dclk(timings);
1286 		break;
1287 	default:
1288 		err = -EINVAL;
1289 
1290 	}
1291 
1292 	if (err || (!(flags & FB_IGNOREMON) &&
1293 	    (timings->vfreq < vfmin || timings->vfreq > vfmax ||
1294 	     timings->hfreq < hfmin || timings->hfreq > hfmax ||
1295 	     timings->dclk < dclkmin || timings->dclk > dclkmax))) {
1296 		err = -EINVAL;
1297 	} else {
1298 		var->pixclock = KHZ2PICOS(timings->dclk/1000);
1299 		var->hsync_len = (timings->htotal * 8)/100;
1300 		var->right_margin = (timings->hblank/2) - var->hsync_len;
1301 		var->left_margin = timings->hblank - var->right_margin -
1302 			var->hsync_len;
1303 		var->vsync_len = (3 * interlace)/dscan;
1304 		var->lower_margin = (1 * interlace)/dscan;
1305 		var->upper_margin = (timings->vblank * interlace)/dscan -
1306 			(var->vsync_len + var->lower_margin);
1307 	}
1308 
1309 	kfree(timings);
1310 	return err;
1311 }
1312 
1313 #ifdef CONFIG_VIDEOMODE_HELPERS
fb_videomode_from_videomode(const struct videomode * vm,struct fb_videomode * fbmode)1314 int fb_videomode_from_videomode(const struct videomode *vm,
1315 				struct fb_videomode *fbmode)
1316 {
1317 	unsigned int htotal, vtotal, total;
1318 
1319 	fbmode->xres = vm->hactive;
1320 	fbmode->left_margin = vm->hback_porch;
1321 	fbmode->right_margin = vm->hfront_porch;
1322 	fbmode->hsync_len = vm->hsync_len;
1323 
1324 	fbmode->yres = vm->vactive;
1325 	fbmode->upper_margin = vm->vback_porch;
1326 	fbmode->lower_margin = vm->vfront_porch;
1327 	fbmode->vsync_len = vm->vsync_len;
1328 
1329 	/* prevent division by zero in KHZ2PICOS macro */
1330 	fbmode->pixclock = vm->pixelclock ?
1331 			KHZ2PICOS(vm->pixelclock / 1000) : 0;
1332 
1333 	fbmode->sync = 0;
1334 	fbmode->vmode = 0;
1335 	if (vm->flags & DISPLAY_FLAGS_HSYNC_HIGH)
1336 		fbmode->sync |= FB_SYNC_HOR_HIGH_ACT;
1337 	if (vm->flags & DISPLAY_FLAGS_VSYNC_HIGH)
1338 		fbmode->sync |= FB_SYNC_VERT_HIGH_ACT;
1339 	if (vm->flags & DISPLAY_FLAGS_INTERLACED)
1340 		fbmode->vmode |= FB_VMODE_INTERLACED;
1341 	if (vm->flags & DISPLAY_FLAGS_DOUBLESCAN)
1342 		fbmode->vmode |= FB_VMODE_DOUBLE;
1343 	fbmode->flag = 0;
1344 
1345 	htotal = vm->hactive + vm->hfront_porch + vm->hback_porch +
1346 		 vm->hsync_len;
1347 	vtotal = vm->vactive + vm->vfront_porch + vm->vback_porch +
1348 		 vm->vsync_len;
1349 	/* prevent division by zero */
1350 	total = htotal * vtotal;
1351 	if (total) {
1352 		fbmode->refresh = vm->pixelclock / total;
1353 	/* a mode must have htotal and vtotal != 0 or it is invalid */
1354 	} else {
1355 		fbmode->refresh = 0;
1356 		return -EINVAL;
1357 	}
1358 
1359 	return 0;
1360 }
1361 EXPORT_SYMBOL_GPL(fb_videomode_from_videomode);
1362 
1363 #ifdef CONFIG_OF
dump_fb_videomode(const struct fb_videomode * m)1364 static inline void dump_fb_videomode(const struct fb_videomode *m)
1365 {
1366 	pr_debug("fb_videomode = %ux%u@%uHz (%ukHz) %u %u %u %u %u %u %u %u %u\n",
1367 		 m->xres, m->yres, m->refresh, m->pixclock, m->left_margin,
1368 		 m->right_margin, m->upper_margin, m->lower_margin,
1369 		 m->hsync_len, m->vsync_len, m->sync, m->vmode, m->flag);
1370 }
1371 
1372 /**
1373  * of_get_fb_videomode - get a fb_videomode from devicetree
1374  * @np: device_node with the timing specification
1375  * @fb: will be set to the return value
1376  * @index: index into the list of display timings in devicetree
1377  *
1378  * DESCRIPTION:
1379  * This function is expensive and should only be used, if only one mode is to be
1380  * read from DT. To get multiple modes start with of_get_display_timings ond
1381  * work with that instead.
1382  */
of_get_fb_videomode(struct device_node * np,struct fb_videomode * fb,int index)1383 int of_get_fb_videomode(struct device_node *np, struct fb_videomode *fb,
1384 			int index)
1385 {
1386 	struct videomode vm;
1387 	int ret;
1388 
1389 	ret = of_get_videomode(np, &vm, index);
1390 	if (ret)
1391 		return ret;
1392 
1393 	ret = fb_videomode_from_videomode(&vm, fb);
1394 	if (ret)
1395 		return ret;
1396 
1397 	pr_debug("%pOF: got %dx%d display mode\n",
1398 		np, vm.hactive, vm.vactive);
1399 	dump_fb_videomode(fb);
1400 
1401 	return 0;
1402 }
1403 EXPORT_SYMBOL_GPL(of_get_fb_videomode);
1404 #endif /* CONFIG_OF */
1405 #endif /* CONFIG_VIDEOMODE_HELPERS */
1406 
1407 #else
fb_parse_edid(unsigned char * edid,struct fb_var_screeninfo * var)1408 int fb_parse_edid(unsigned char *edid, struct fb_var_screeninfo *var)
1409 {
1410 	return 1;
1411 }
fb_edid_to_monspecs(unsigned char * edid,struct fb_monspecs * specs)1412 void fb_edid_to_monspecs(unsigned char *edid, struct fb_monspecs *specs)
1413 {
1414 }
fb_destroy_modedb(struct fb_videomode * modedb)1415 void fb_destroy_modedb(struct fb_videomode *modedb)
1416 {
1417 }
fb_get_mode(int flags,u32 val,struct fb_var_screeninfo * var,struct fb_info * info)1418 int fb_get_mode(int flags, u32 val, struct fb_var_screeninfo *var,
1419 		struct fb_info *info)
1420 {
1421 	return -EINVAL;
1422 }
1423 #endif /* CONFIG_FB_MODE_HELPERS */
1424 
1425 /*
1426  * fb_validate_mode - validates var against monitor capabilities
1427  * @var: pointer to fb_var_screeninfo
1428  * @info: pointer to fb_info
1429  *
1430  * DESCRIPTION:
1431  * Validates video mode against monitor capabilities specified in
1432  * info->monspecs.
1433  *
1434  * REQUIRES:
1435  * A valid info->monspecs.
1436  */
fb_validate_mode(const struct fb_var_screeninfo * var,struct fb_info * info)1437 int fb_validate_mode(const struct fb_var_screeninfo *var, struct fb_info *info)
1438 {
1439 	u32 hfreq, vfreq, htotal, vtotal, pixclock;
1440 	u32 hfmin, hfmax, vfmin, vfmax, dclkmin, dclkmax;
1441 
1442 	/*
1443 	 * If monspecs are invalid, use values that are enough
1444 	 * for 640x480@60
1445 	 */
1446 	if (!info->monspecs.hfmax || !info->monspecs.vfmax ||
1447 	    !info->monspecs.dclkmax ||
1448 	    info->monspecs.hfmax < info->monspecs.hfmin ||
1449 	    info->monspecs.vfmax < info->monspecs.vfmin ||
1450 	    info->monspecs.dclkmax < info->monspecs.dclkmin) {
1451 		hfmin = 29000; hfmax = 30000;
1452 		vfmin = 60; vfmax = 60;
1453 		dclkmin = 0; dclkmax = 25000000;
1454 	} else {
1455 		hfmin = info->monspecs.hfmin;
1456 		hfmax = info->monspecs.hfmax;
1457 		vfmin = info->monspecs.vfmin;
1458 		vfmax = info->monspecs.vfmax;
1459 		dclkmin = info->monspecs.dclkmin;
1460 		dclkmax = info->monspecs.dclkmax;
1461 	}
1462 
1463 	if (!var->pixclock)
1464 		return -EINVAL;
1465 	pixclock = PICOS2KHZ(var->pixclock) * 1000;
1466 
1467 	htotal = var->xres + var->right_margin + var->hsync_len +
1468 		var->left_margin;
1469 	vtotal = var->yres + var->lower_margin + var->vsync_len +
1470 		var->upper_margin;
1471 
1472 	if (var->vmode & FB_VMODE_INTERLACED)
1473 		vtotal /= 2;
1474 	if (var->vmode & FB_VMODE_DOUBLE)
1475 		vtotal *= 2;
1476 
1477 	hfreq = pixclock/htotal;
1478 	hfreq = (hfreq + 500) / 1000 * 1000;
1479 
1480 	vfreq = hfreq/vtotal;
1481 
1482 	return (vfreq < vfmin || vfreq > vfmax ||
1483 		hfreq < hfmin || hfreq > hfmax ||
1484 		pixclock < dclkmin || pixclock > dclkmax) ?
1485 		-EINVAL : 0;
1486 }
1487 
1488 /*
1489  * We need to ensure that the EDID block is only returned for
1490  * the primary graphics adapter.
1491  */
1492 
1493 #if defined(CONFIG_FIRMWARE_EDID)
fb_firmware_edid(struct device * device)1494 const unsigned char *fb_firmware_edid(struct device *device)
1495 {
1496 	struct pci_dev *dev = NULL;
1497 	struct resource *res = NULL;
1498 	unsigned char *edid = NULL;
1499 
1500 	if (device)
1501 		dev = to_pci_dev(device);
1502 
1503 	if (dev)
1504 		res = &dev->resource[PCI_ROM_RESOURCE];
1505 
1506 	if (res && res->flags & IORESOURCE_ROM_SHADOW)
1507 		edid = edid_info.dummy;
1508 
1509 	return edid;
1510 }
1511 #else
fb_firmware_edid(struct device * device)1512 const unsigned char *fb_firmware_edid(struct device *device)
1513 {
1514 	return NULL;
1515 }
1516 #endif
1517 EXPORT_SYMBOL(fb_firmware_edid);
1518 
1519 EXPORT_SYMBOL(fb_parse_edid);
1520 EXPORT_SYMBOL(fb_edid_to_monspecs);
1521 EXPORT_SYMBOL(fb_get_mode);
1522 EXPORT_SYMBOL(fb_validate_mode);
1523 EXPORT_SYMBOL(fb_destroy_modedb);
1524