1 /* $NetBSD: vesagtf.c,v 1.3 2014/03/21 22:00:00 dholland Exp $ */
2
3 /*-
4 * Copyright (c) 2006 Itronix Inc.
5 * All rights reserved.
6 *
7 * Written by Garrett D'Amore for Itronix Inc.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. The name of Itronix Inc. may not be used to endorse
18 * or promote products derived from this software without specific
19 * prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY ITRONIX INC. ``AS IS'' AND ANY EXPRESS
22 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
23 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL ITRONIX INC. BE LIABLE FOR ANY
25 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
27 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
29 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
30 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
31 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 */
33
34 /*
35 * This was derived from a userland GTF program supplied by NVIDIA.
36 * NVIDIA's original boilerplate follows.
37 *
38 * Note that I have heavily modified the program for use in the EDID
39 * kernel code for NetBSD, including removing the use of floating
40 * point operations and making significant adjustments to minimize
41 * error propagation while operating with integer only math.
42 *
43 * This has required the use of 64-bit integers in a few places, but
44 * the upshot is that for a calculation of 1920x1200x85 (as an
45 * example), the error deviates by only ~.004% relative to the
46 * floating point version. This error is *well* within VESA
47 * tolerances.
48 */
49
50 /*
51 * Copyright (c) 2001, Andy Ritger aritger@nvidia.com
52 * All rights reserved.
53 *
54 * Redistribution and use in source and binary forms, with or without
55 * modification, are permitted provided that the following conditions
56 * are met:
57 *
58 * o Redistributions of source code must retain the above copyright
59 * notice, this list of conditions and the following disclaimer.
60 * o Redistributions in binary form must reproduce the above copyright
61 * notice, this list of conditions and the following disclaimer
62 * in the documentation and/or other materials provided with the
63 * distribution.
64 * o Neither the name of NVIDIA nor the names of its contributors
65 * may be used to endorse or promote products derived from this
66 * software without specific prior written permission.
67 *
68 *
69 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
70 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT
71 * NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
72 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
73 * THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
74 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
75 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
76 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
77 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
78 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
79 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
80 * POSSIBILITY OF SUCH DAMAGE.
81 *
82 *
83 *
84 * This program is based on the Generalized Timing Formula(GTF TM)
85 * Standard Version: 1.0, Revision: 1.0
86 *
87 * The GTF Document contains the following Copyright information:
88 *
89 * Copyright (c) 1994, 1995, 1996 - Video Electronics Standards
90 * Association. Duplication of this document within VESA member
91 * companies for review purposes is permitted. All other rights
92 * reserved.
93 *
94 * While every precaution has been taken in the preparation
95 * of this standard, the Video Electronics Standards Association and
96 * its contributors assume no responsibility for errors or omissions,
97 * and make no warranties, expressed or implied, of functionality
98 * of suitability for any purpose. The sample code contained within
99 * this standard may be used without restriction.
100 *
101 *
102 *
103 * The GTF EXCEL(TM) SPREADSHEET, a sample (and the definitive)
104 * implementation of the GTF Timing Standard, is available at:
105 *
106 * ftp://ftp.vesa.org/pub/GTF/GTF_V1R1.xls
107 *
108 *
109 *
110 * This program takes a desired resolution and vertical refresh rate,
111 * and computes mode timings according to the GTF Timing Standard.
112 * These mode timings can then be formatted as an XFree86 modeline
113 * or a mode description for use by fbset(8).
114 *
115 *
116 *
117 * NOTES:
118 *
119 * The GTF allows for computation of "margins" (the visible border
120 * surrounding the addressable video); on most non-overscan type
121 * systems, the margin period is zero. I've implemented the margin
122 * computations but not enabled it because 1) I don't really have
123 * any experience with this, and 2) neither XFree86 modelines nor
124 * fbset fb.modes provide an obvious way for margin timings to be
125 * included in their mode descriptions (needs more investigation).
126 *
127 * The GTF provides for computation of interlaced mode timings;
128 * I've implemented the computations but not enabled them, yet.
129 * I should probably enable and test this at some point.
130 *
131 *
132 *
133 * TODO:
134 *
135 * o Add support for interlaced modes.
136 *
137 * o Implement the other portions of the GTF: compute mode timings
138 * given either the desired pixel clock or the desired horizontal
139 * frequency.
140 *
141 * o It would be nice if this were more general purpose to do things
142 * outside the scope of the GTF: like generate double scan mode
143 * timings, for example.
144 *
145 * o Printing digits to the right of the decimal point when the
146 * digits are 0 annoys me.
147 *
148 * o Error checking.
149 *
150 */
151
152
153 #ifdef _KERNEL
154 #include <sys/cdefs.h>
155
156 __KERNEL_RCSID(0, "$NetBSD: vesagtf.c,v 1.3 2014/03/21 22:00:00 dholland Exp $");
157 #include <sys/types.h>
158 #include <sys/param.h>
159 #include <sys/systm.h>
160 #include <dev/videomode/videomode.h>
161 #include <dev/videomode/vesagtf.h>
162 #else
163 #include <stdio.h>
164 #include <stdlib.h>
165 #include <sys/types.h>
166 #include "videomode.h"
167 #include "vesagtf.h"
168
169 void print_xf86_mode(struct videomode *m);
170 #endif
171
172 #define CELL_GRAN 8 /* assumed character cell granularity */
173
174 /* C' and M' are part of the Blanking Duty Cycle computation */
175 /*
176 * #define C_PRIME (((C - J) * K/256.0) + J)
177 * #define M_PRIME (K/256.0 * M)
178 */
179
180 /*
181 * C' and M' multiplied by 256 to give integer math. Make sure to
182 * scale results using these back down, appropriately.
183 */
184 #define C_PRIME256(p) (((p->C - p->J) * p->K) + (p->J * 256))
185 #define M_PRIME256(p) (p->K * p->M)
186
187 #define DIVIDE(x,y) (((x) + ((y) / 2)) / (y))
188
189 /*
190 * print_value() - print the result of the named computation; this is
191 * useful when comparing against the GTF EXCEL spreadsheet.
192 */
193
194 #ifdef GTFDEBUG
195
196 static void
print_value(int n,const char * name,unsigned val)197 print_value(int n, const char *name, unsigned val)
198 {
199 printf("%2d: %-27s: %u\n", n, name, val);
200 }
201 #else
202 #define print_value(n, name, val)
203 #endif
204
205
206 /*
207 * vert_refresh() - as defined by the GTF Timing Standard, compute the
208 * Stage 1 Parameters using the vertical refresh frequency. In other
209 * words: input a desired resolution and desired refresh rate, and
210 * output the GTF mode timings.
211 *
212 * XXX All the code is in place to compute interlaced modes, but I don't
213 * feel like testing it right now.
214 *
215 * XXX margin computations are implemented but not tested (nor used by
216 * XFree86 of fbset mode descriptions, from what I can tell).
217 */
218
219 void
vesagtf_mode_params(unsigned h_pixels,unsigned v_lines,unsigned freq,struct vesagtf_params * params,int flags,struct videomode * vmp)220 vesagtf_mode_params(unsigned h_pixels, unsigned v_lines, unsigned freq,
221 struct vesagtf_params *params, int flags, struct videomode *vmp)
222 {
223 unsigned v_field_rqd;
224 unsigned top_margin;
225 unsigned bottom_margin;
226 unsigned interlace;
227 uint64_t h_period_est;
228 unsigned vsync_plus_bp;
229 unsigned v_back_porch __unused;
230 unsigned total_v_lines;
231 uint64_t v_field_est;
232 uint64_t h_period;
233 unsigned v_field_rate;
234 unsigned v_frame_rate __unused;
235 unsigned left_margin;
236 unsigned right_margin;
237 unsigned total_active_pixels;
238 uint64_t ideal_duty_cycle;
239 unsigned h_blank;
240 unsigned total_pixels;
241 unsigned pixel_freq;
242
243 unsigned h_sync;
244 unsigned h_front_porch;
245 unsigned v_odd_front_porch_lines;
246
247 #ifdef GTFDEBUG
248 unsigned h_freq;
249 #endif
250
251 /* 1. In order to give correct results, the number of horizontal
252 * pixels requested is first processed to ensure that it is divisible
253 * by the character size, by rounding it to the nearest character
254 * cell boundary:
255 *
256 * [H PIXELS RND] = ((ROUND([H PIXELS]/[CELL GRAN RND],0))*[CELLGRAN RND])
257 */
258
259 h_pixels = DIVIDE(h_pixels, CELL_GRAN) * CELL_GRAN;
260
261 print_value(1, "[H PIXELS RND]", h_pixels);
262
263
264 /* 2. If interlace is requested, the number of vertical lines assumed
265 * by the calculation must be halved, as the computation calculates
266 * the number of vertical lines per field. In either case, the
267 * number of lines is rounded to the nearest integer.
268 *
269 * [V LINES RND] = IF([INT RQD?]="y", ROUND([V LINES]/2,0),
270 * ROUND([V LINES],0))
271 */
272
273 v_lines = (flags & VESAGTF_FLAG_ILACE) ? DIVIDE(v_lines, 2) : v_lines;
274
275 print_value(2, "[V LINES RND]", v_lines);
276
277
278 /* 3. Find the frame rate required:
279 *
280 * [V FIELD RATE RQD] = IF([INT RQD?]="y", [I/P FREQ RQD]*2,
281 * [I/P FREQ RQD])
282 */
283
284 v_field_rqd = (flags & VESAGTF_FLAG_ILACE) ? (freq * 2) : (freq);
285
286 print_value(3, "[V FIELD RATE RQD]", v_field_rqd);
287
288
289 /* 4. Find number of lines in Top margin:
290 * 5. Find number of lines in Bottom margin:
291 *
292 * [TOP MARGIN (LINES)] = IF([MARGINS RQD?]="Y",
293 * ROUND(([MARGIN%]/100*[V LINES RND]),0),
294 * 0)
295 *
296 * Ditto for bottom margin. Note that instead of %, we use PPT, which
297 * is parts per thousand. This helps us with integer math.
298 */
299
300 top_margin = bottom_margin = (flags & VESAGTF_FLAG_MARGINS) ?
301 DIVIDE(v_lines * params->margin_ppt, 1000) : 0;
302
303 print_value(4, "[TOP MARGIN (LINES)]", top_margin);
304 print_value(5, "[BOT MARGIN (LINES)]", bottom_margin);
305
306
307 /* 6. If interlace is required, then set variable [INTERLACE]=0.5:
308 *
309 * [INTERLACE]=(IF([INT RQD?]="y",0.5,0))
310 *
311 * To make this integer friendly, we use some special hacks in step
312 * 7 below. Please read those comments to understand why I am using
313 * a whole number of 1.0 instead of 0.5 here.
314 */
315 interlace = (flags & VESAGTF_FLAG_ILACE) ? 1 : 0;
316
317 print_value(6, "[2*INTERLACE]", interlace);
318
319
320 /* 7. Estimate the Horizontal period
321 *
322 * [H PERIOD EST] = ((1/[V FIELD RATE RQD]) - [MIN VSYNC+BP]/1000000) /
323 * ([V LINES RND] + (2*[TOP MARGIN (LINES)]) +
324 * [MIN PORCH RND]+[INTERLACE]) * 1000000
325 *
326 * To make it integer friendly, we pre-multiply the 1000000 to get to
327 * usec. This gives us:
328 *
329 * [H PERIOD EST] = ((1000000/[V FIELD RATE RQD]) - [MIN VSYNC+BP]) /
330 * ([V LINES RND] + (2 * [TOP MARGIN (LINES)]) +
331 * [MIN PORCH RND]+[INTERLACE])
332 *
333 * The other problem is that the interlace value is wrong. To get
334 * the interlace to a whole number, we multiply both the numerator and
335 * divisor by 2, so we can use a value of either 1 or 0 for the interlace
336 * factor.
337 *
338 * This gives us:
339 *
340 * [H PERIOD EST] = ((2*((1000000/[V FIELD RATE RQD]) - [MIN VSYNC+BP])) /
341 * (2*([V LINES RND] + (2*[TOP MARGIN (LINES)]) +
342 * [MIN PORCH RND]) + [2*INTERLACE]))
343 *
344 * Finally we multiply by another 1000, to get value in picosec.
345 * Why picosec? To minimize rounding errors. Gotta love integer
346 * math and error propagation.
347 */
348
349 h_period_est = DIVIDE(((DIVIDE(2000000000000ULL, v_field_rqd)) -
350 (2000000 * params->min_vsbp)),
351 ((2 * (v_lines + (2 * top_margin) + params->min_porch)) + interlace));
352
353 print_value(7, "[H PERIOD EST (ps)]", h_period_est);
354
355
356 /* 8. Find the number of lines in V sync + back porch:
357 *
358 * [V SYNC+BP] = ROUND(([MIN VSYNC+BP]/[H PERIOD EST]),0)
359 *
360 * But recall that h_period_est is in psec. So multiply by 1000000.
361 */
362
363 vsync_plus_bp = DIVIDE(params->min_vsbp * 1000000, h_period_est);
364
365 print_value(8, "[V SYNC+BP]", vsync_plus_bp);
366
367
368 /* 9. Find the number of lines in V back porch alone:
369 *
370 * [V BACK PORCH] = [V SYNC+BP] - [V SYNC RND]
371 *
372 * XXX is "[V SYNC RND]" a typo? should be [V SYNC RQD]?
373 */
374
375 v_back_porch = vsync_plus_bp - params->vsync_rqd;
376
377 print_value(9, "[V BACK PORCH]", v_back_porch);
378
379
380 /* 10. Find the total number of lines in Vertical field period:
381 *
382 * [TOTAL V LINES] = [V LINES RND] + [TOP MARGIN (LINES)] +
383 * [BOT MARGIN (LINES)] + [V SYNC+BP] + [INTERLACE] +
384 * [MIN PORCH RND]
385 */
386
387 total_v_lines = v_lines + top_margin + bottom_margin + vsync_plus_bp +
388 interlace + params->min_porch;
389
390 print_value(10, "[TOTAL V LINES]", total_v_lines);
391
392
393 /* 11. Estimate the Vertical field frequency:
394 *
395 * [V FIELD RATE EST] = 1 / [H PERIOD EST] / [TOTAL V LINES] * 1000000
396 *
397 * Again, we want to pre multiply by 10^9 to convert for nsec, thereby
398 * making it usable in integer math.
399 *
400 * So we get:
401 *
402 * [V FIELD RATE EST] = 1000000000 / [H PERIOD EST] / [TOTAL V LINES]
403 *
404 * This is all scaled to get the result in uHz. Again, we're trying to
405 * minimize error propagation.
406 */
407 v_field_est = DIVIDE(DIVIDE(1000000000000000ULL, h_period_est),
408 total_v_lines);
409
410 print_value(11, "[V FIELD RATE EST(uHz)]", v_field_est);
411
412
413 /* 12. Find the actual horizontal period:
414 *
415 * [H PERIOD] = [H PERIOD EST] / ([V FIELD RATE RQD] / [V FIELD RATE EST])
416 */
417
418 h_period = DIVIDE(h_period_est * v_field_est, v_field_rqd * 1000);
419
420 print_value(12, "[H PERIOD(ps)]", h_period);
421
422
423 /* 13. Find the actual Vertical field frequency:
424 *
425 * [V FIELD RATE] = 1 / [H PERIOD] / [TOTAL V LINES] * 1000000
426 *
427 * And again, we convert to nsec ahead of time, giving us:
428 *
429 * [V FIELD RATE] = 1000000 / [H PERIOD] / [TOTAL V LINES]
430 *
431 * And another rescaling back to mHz. Gotta love it.
432 */
433
434 v_field_rate = DIVIDE(1000000000000ULL, h_period * total_v_lines);
435
436 print_value(13, "[V FIELD RATE]", v_field_rate);
437
438
439 /* 14. Find the Vertical frame frequency:
440 *
441 * [V FRAME RATE] = (IF([INT RQD?]="y", [V FIELD RATE]/2, [V FIELD RATE]))
442 *
443 * N.B. that the result here is in mHz.
444 */
445
446 v_frame_rate = (flags & VESAGTF_FLAG_ILACE) ?
447 v_field_rate / 2 : v_field_rate;
448
449 print_value(14, "[V FRAME RATE]", v_frame_rate);
450
451
452 /* 15. Find number of pixels in left margin:
453 * 16. Find number of pixels in right margin:
454 *
455 * [LEFT MARGIN (PIXELS)] = (IF( [MARGINS RQD?]="Y",
456 * (ROUND( ([H PIXELS RND] * [MARGIN%] / 100 /
457 * [CELL GRAN RND]),0)) * [CELL GRAN RND],
458 * 0))
459 *
460 * Again, we deal with margin percentages as PPT (parts per thousand).
461 * And the calculations for left and right are the same.
462 */
463
464 left_margin = right_margin = (flags & VESAGTF_FLAG_MARGINS) ?
465 DIVIDE(DIVIDE(h_pixels * params->margin_ppt, 1000),
466 CELL_GRAN) * CELL_GRAN : 0;
467
468 print_value(15, "[LEFT MARGIN (PIXELS)]", left_margin);
469 print_value(16, "[RIGHT MARGIN (PIXELS)]", right_margin);
470
471
472 /* 17. Find total number of active pixels in image and left and right
473 * margins:
474 *
475 * [TOTAL ACTIVE PIXELS] = [H PIXELS RND] + [LEFT MARGIN (PIXELS)] +
476 * [RIGHT MARGIN (PIXELS)]
477 */
478
479 total_active_pixels = h_pixels + left_margin + right_margin;
480
481 print_value(17, "[TOTAL ACTIVE PIXELS]", total_active_pixels);
482
483
484 /* 18. Find the ideal blanking duty cycle from the blanking duty cycle
485 * equation:
486 *
487 * [IDEAL DUTY CYCLE] = [C'] - ([M']*[H PERIOD]/1000)
488 *
489 * However, we have modified values for [C'] as [256*C'] and
490 * [M'] as [256*M']. Again the idea here is to get good scaling.
491 * We use 256 as the factor to make the math fast.
492 *
493 * Note that this means that we have to scale it appropriately in
494 * later calculations.
495 *
496 * The ending result is that our ideal_duty_cycle is 256000x larger
497 * than the duty cycle used by VESA. But again, this reduces error
498 * propagation.
499 */
500
501 ideal_duty_cycle =
502 ((C_PRIME256(params) * 1000) -
503 (M_PRIME256(params) * h_period / 1000000));
504
505 print_value(18, "[IDEAL DUTY CYCLE]", ideal_duty_cycle);
506
507
508 /* 19. Find the number of pixels in the blanking time to the nearest
509 * double character cell:
510 *
511 * [H BLANK (PIXELS)] = (ROUND(([TOTAL ACTIVE PIXELS] *
512 * [IDEAL DUTY CYCLE] /
513 * (100-[IDEAL DUTY CYCLE]) /
514 * (2*[CELL GRAN RND])), 0))
515 * * (2*[CELL GRAN RND])
516 *
517 * Of course, we adjust to make this rounding work in integer math.
518 */
519
520 h_blank = DIVIDE(DIVIDE(total_active_pixels * ideal_duty_cycle,
521 (256000 * 100ULL) - ideal_duty_cycle),
522 2 * CELL_GRAN) * (2 * CELL_GRAN);
523
524 print_value(19, "[H BLANK (PIXELS)]", h_blank);
525
526
527 /* 20. Find total number of pixels:
528 *
529 * [TOTAL PIXELS] = [TOTAL ACTIVE PIXELS] + [H BLANK (PIXELS)]
530 */
531
532 total_pixels = total_active_pixels + h_blank;
533
534 print_value(20, "[TOTAL PIXELS]", total_pixels);
535
536
537 /* 21. Find pixel clock frequency:
538 *
539 * [PIXEL FREQ] = [TOTAL PIXELS] / [H PERIOD]
540 *
541 * We calculate this in Hz rather than MHz, to get a value that
542 * is usable with integer math. Recall that the [H PERIOD] is in
543 * nsec.
544 */
545
546 pixel_freq = DIVIDE(total_pixels * 1000000, DIVIDE(h_period, 1000));
547
548 print_value(21, "[PIXEL FREQ]", pixel_freq);
549
550
551 /* 22. Find horizontal frequency:
552 *
553 * [H FREQ] = 1000 / [H PERIOD]
554 *
555 * I've ifdef'd this out, because we don't need it for any of
556 * our calculations.
557 * We calculate this in Hz rather than kHz, to avoid rounding
558 * errors. Recall that the [H PERIOD] is in usec.
559 */
560
561 #ifdef GTFDEBUG
562 h_freq = 1000000000 / h_period;
563
564 print_value(22, "[H FREQ]", h_freq);
565 #endif
566
567
568
569 /* Stage 1 computations are now complete; I should really pass
570 the results to another function and do the Stage 2
571 computations, but I only need a few more values so I'll just
572 append the computations here for now */
573
574
575
576 /* 17. Find the number of pixels in the horizontal sync period:
577 *
578 * [H SYNC (PIXELS)] =(ROUND(([H SYNC%] / 100 * [TOTAL PIXELS] /
579 * [CELL GRAN RND]),0))*[CELL GRAN RND]
580 *
581 * Rewriting for integer math:
582 *
583 * [H SYNC (PIXELS)]=(ROUND((H SYNC%] * [TOTAL PIXELS] / 100 /
584 * [CELL GRAN RND),0))*[CELL GRAN RND]
585 */
586
587 h_sync = DIVIDE(((params->hsync_pct * total_pixels) / 100), CELL_GRAN) *
588 CELL_GRAN;
589
590 print_value(17, "[H SYNC (PIXELS)]", h_sync);
591
592
593 /* 18. Find the number of pixels in the horizontal front porch period:
594 *
595 * [H FRONT PORCH (PIXELS)] = ([H BLANK (PIXELS)]/2)-[H SYNC (PIXELS)]
596 *
597 * Note that h_blank is always an even number of characters (i.e.
598 * h_blank % (CELL_GRAN * 2) == 0)
599 */
600
601 h_front_porch = (h_blank / 2) - h_sync;
602
603 print_value(18, "[H FRONT PORCH (PIXELS)]", h_front_porch);
604
605
606 /* 36. Find the number of lines in the odd front porch period:
607 *
608 * [V ODD FRONT PORCH(LINES)]=([MIN PORCH RND]+[INTERLACE])
609 *
610 * Adjusting for the fact that the interlace is scaled:
611 *
612 * [V ODD FRONT PORCH(LINES)]=(([MIN PORCH RND] * 2) + [2*INTERLACE]) / 2
613 */
614
615 v_odd_front_porch_lines = ((2 * params->min_porch) + interlace) / 2;
616
617 print_value(36, "[V ODD FRONT PORCH(LINES)]", v_odd_front_porch_lines);
618
619
620 /* finally, pack the results in the mode struct */
621
622 vmp->hsync_start = h_pixels + h_front_porch;
623 vmp->hsync_end = vmp->hsync_start + h_sync;
624 vmp->htotal = total_pixels;
625 vmp->hdisplay = h_pixels;
626
627 vmp->vsync_start = v_lines + v_odd_front_porch_lines;
628 vmp->vsync_end = vmp->vsync_start + params->vsync_rqd;
629 vmp->vtotal = total_v_lines;
630 vmp->vdisplay = v_lines;
631
632 vmp->dot_clock = pixel_freq;
633
634 }
635
636 void
vesagtf_mode(unsigned x,unsigned y,unsigned refresh,struct videomode * vmp)637 vesagtf_mode(unsigned x, unsigned y, unsigned refresh, struct videomode *vmp)
638 {
639 struct vesagtf_params params;
640
641 params.margin_ppt = VESAGTF_MARGIN_PPT;
642 params.min_porch = VESAGTF_MIN_PORCH;
643 params.vsync_rqd = VESAGTF_VSYNC_RQD;
644 params.hsync_pct = VESAGTF_HSYNC_PCT;
645 params.min_vsbp = VESAGTF_MIN_VSBP;
646 params.M = VESAGTF_M;
647 params.C = VESAGTF_C;
648 params.K = VESAGTF_K;
649 params.J = VESAGTF_J;
650
651 vesagtf_mode_params(x, y, refresh, ¶ms, 0, vmp);
652 }
653
654 /*
655 * The tidbit here is so that you can compile this file as a
656 * standalone user program to generate X11 modelines using VESA GTF.
657 * This also allows for testing of the code itself, without
658 * necessitating a full kernel recompile.
659 */
660
661 /* print_xf86_mode() - print the XFree86 modeline, given mode timings. */
662
663 #if !defined(__minix)
664 #ifndef _KERNEL
665 void
print_xf86_mode(struct videomode * vmp)666 print_xf86_mode (struct videomode *vmp)
667 {
668 float vf, hf;
669
670 hf = 1000.0 * vmp->dot_clock / vmp->htotal;
671 vf = 1.0 * hf / vmp->vtotal;
672
673 printf("\n");
674 printf(" # %dx%d @ %.2f Hz (GTF) hsync: %.2f kHz; pclk: %.2f MHz\n",
675 vmp->hdisplay, vmp->vdisplay, vf, hf, vmp->dot_clock / 1000.0);
676
677 printf(" Modeline \"%dx%d_%.2f\" %.2f"
678 " %d %d %d %d"
679 " %d %d %d %d"
680 " -HSync +Vsync\n\n",
681 vmp->hdisplay, vmp->vdisplay, vf, (vmp->dot_clock / 1000.0),
682 vmp->hdisplay, vmp->hsync_start, vmp->hsync_end, vmp->htotal,
683 vmp->vdisplay, vmp->vsync_start, vmp->vsync_end, vmp->vtotal);
684 }
685
686 int
main(int argc,char * argv[])687 main (int argc, char *argv[])
688 {
689 struct videomode m;
690
691 if (argc != 4) {
692 printf("usage: %s x y refresh\n", argv[0]);
693 exit(1);
694 }
695
696 vesagtf_mode(atoi(argv[1]), atoi(argv[2]), atoi(argv[3]), &m);
697
698 print_xf86_mode(&m);
699
700 return 0;
701
702 }
703 #endif
704 #endif /* !defined(__minix) */
705