1 /* $NetBSD: vesagtf.c,v 1.4 2021/12/25 13:51:31 mlelstv 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 1.4 2021/12/25 13:51:31 mlelstv Exp $");
157 #include <sys/types.h>
158 #include <sys/param.h>
159 #include <sys/systm.h>
160 #else
161 #include <stdio.h>
162 #include <stdlib.h>
163 #include <inttypes.h>
164 #endif
165 #include <dev/videomode/videomode.h>
166 #include <dev/videomode/vesagtf.h>
167
168 #define CELL_GRAN 8 /* assumed character cell granularity */
169
170 /* C' and M' are part of the Blanking Duty Cycle computation */
171 /*
172 * #define C_PRIME (((C - J) * K/256.0) + J)
173 * #define M_PRIME (K/256.0 * M)
174 */
175
176 /*
177 * C' and M' multiplied by 256 to give integer math. Make sure to
178 * scale results using these back down, appropriately.
179 */
180 #define C_PRIME256(p) (((p->C - p->J) * p->K) + (p->J * 256))
181 #define M_PRIME256(p) (p->K * p->M)
182
183 #define DIVIDE(x,y) (((x) + ((y) / 2)) / (y))
184
185 /*
186 * print_value() - print the result of the named computation; this is
187 * useful when comparing against the GTF EXCEL spreadsheet.
188 */
189
190 #ifdef GTFDEBUG
191
192 static void
print_value(int n,const char * name,unsigned val)193 print_value(int n, const char *name, unsigned val)
194 {
195 printf("%2d: %-27s: %u\n", n, name, val);
196 }
197 #else
198 #define print_value(n, name, val)
199 #endif
200
201
202 /*
203 * vert_refresh() - as defined by the GTF Timing Standard, compute the
204 * Stage 1 Parameters using the vertical refresh frequency. In other
205 * words: input a desired resolution and desired refresh rate, and
206 * output the GTF mode timings.
207 *
208 * XXX All the code is in place to compute interlaced modes, but I don't
209 * feel like testing it right now.
210 *
211 * XXX margin computations are implemented but not tested (nor used by
212 * XFree86 of fbset mode descriptions, from what I can tell).
213 */
214
215 void
vesagtf_mode_params(unsigned h_pixels,unsigned v_lines,unsigned freq,struct vesagtf_params * params,int flags,struct videomode * vmp)216 vesagtf_mode_params(unsigned h_pixels, unsigned v_lines, unsigned freq,
217 struct vesagtf_params *params, int flags, struct videomode *vmp)
218 {
219 unsigned v_field_rqd;
220 unsigned top_margin;
221 unsigned bottom_margin;
222 unsigned interlace;
223 uint64_t h_period_est;
224 unsigned vsync_plus_bp;
225 unsigned v_back_porch __unused;
226 unsigned total_v_lines;
227 uint64_t v_field_est;
228 uint64_t h_period;
229 unsigned v_field_rate;
230 unsigned v_frame_rate __unused;
231 unsigned left_margin;
232 unsigned right_margin;
233 unsigned total_active_pixels;
234 uint64_t ideal_duty_cycle;
235 unsigned h_blank;
236 unsigned total_pixels;
237 unsigned pixel_freq;
238
239 unsigned h_sync;
240 unsigned h_front_porch;
241 unsigned v_odd_front_porch_lines;
242
243 #ifdef GTFDEBUG
244 unsigned h_freq;
245 #endif
246
247 /* 1. In order to give correct results, the number of horizontal
248 * pixels requested is first processed to ensure that it is divisible
249 * by the character size, by rounding it to the nearest character
250 * cell boundary:
251 *
252 * [H PIXELS RND] = ((ROUND([H PIXELS]/[CELL GRAN RND],0))*[CELLGRAN RND])
253 */
254
255 h_pixels = DIVIDE(h_pixels, CELL_GRAN) * CELL_GRAN;
256
257 print_value(1, "[H PIXELS RND]", h_pixels);
258
259
260 /* 2. If interlace is requested, the number of vertical lines assumed
261 * by the calculation must be halved, as the computation calculates
262 * the number of vertical lines per field. In either case, the
263 * number of lines is rounded to the nearest integer.
264 *
265 * [V LINES RND] = IF([INT RQD?]="y", ROUND([V LINES]/2,0),
266 * ROUND([V LINES],0))
267 */
268
269 v_lines = (flags & VESAGTF_FLAG_ILACE) ? DIVIDE(v_lines, 2) : v_lines;
270
271 print_value(2, "[V LINES RND]", v_lines);
272
273
274 /* 3. Find the frame rate required:
275 *
276 * [V FIELD RATE RQD] = IF([INT RQD?]="y", [I/P FREQ RQD]*2,
277 * [I/P FREQ RQD])
278 */
279
280 v_field_rqd = (flags & VESAGTF_FLAG_ILACE) ? (freq * 2) : (freq);
281
282 print_value(3, "[V FIELD RATE RQD]", v_field_rqd);
283
284
285 /* 4. Find number of lines in Top margin:
286 * 5. Find number of lines in Bottom margin:
287 *
288 * [TOP MARGIN (LINES)] = IF([MARGINS RQD?]="Y",
289 * ROUND(([MARGIN%]/100*[V LINES RND]),0),
290 * 0)
291 *
292 * Ditto for bottom margin. Note that instead of %, we use PPT, which
293 * is parts per thousand. This helps us with integer math.
294 */
295
296 top_margin = bottom_margin = (flags & VESAGTF_FLAG_MARGINS) ?
297 DIVIDE(v_lines * params->margin_ppt, 1000) : 0;
298
299 print_value(4, "[TOP MARGIN (LINES)]", top_margin);
300 print_value(5, "[BOT MARGIN (LINES)]", bottom_margin);
301
302
303 /* 6. If interlace is required, then set variable [INTERLACE]=0.5:
304 *
305 * [INTERLACE]=(IF([INT RQD?]="y",0.5,0))
306 *
307 * To make this integer friendly, we use some special hacks in step
308 * 7 below. Please read those comments to understand why I am using
309 * a whole number of 1.0 instead of 0.5 here.
310 */
311 interlace = (flags & VESAGTF_FLAG_ILACE) ? 1 : 0;
312
313 print_value(6, "[2*INTERLACE]", interlace);
314
315
316 /* 7. Estimate the Horizontal period
317 *
318 * [H PERIOD EST] = ((1/[V FIELD RATE RQD]) - [MIN VSYNC+BP]/1000000) /
319 * ([V LINES RND] + (2*[TOP MARGIN (LINES)]) +
320 * [MIN PORCH RND]+[INTERLACE]) * 1000000
321 *
322 * To make it integer friendly, we pre-multiply the 1000000 to get to
323 * usec. This gives us:
324 *
325 * [H PERIOD EST] = ((1000000/[V FIELD RATE RQD]) - [MIN VSYNC+BP]) /
326 * ([V LINES RND] + (2 * [TOP MARGIN (LINES)]) +
327 * [MIN PORCH RND]+[INTERLACE])
328 *
329 * The other problem is that the interlace value is wrong. To get
330 * the interlace to a whole number, we multiply both the numerator and
331 * divisor by 2, so we can use a value of either 1 or 0 for the interlace
332 * factor.
333 *
334 * This gives us:
335 *
336 * [H PERIOD EST] = ((2*((1000000/[V FIELD RATE RQD]) - [MIN VSYNC+BP])) /
337 * (2*([V LINES RND] + (2*[TOP MARGIN (LINES)]) +
338 * [MIN PORCH RND]) + [2*INTERLACE]))
339 *
340 * Finally we multiply by another 1000, to get value in picosec.
341 * Why picosec? To minimize rounding errors. Gotta love integer
342 * math and error propagation.
343 */
344
345 h_period_est = DIVIDE(((DIVIDE(2000000000000ULL, v_field_rqd)) -
346 (2000000 * params->min_vsbp)),
347 ((2 * (v_lines + (2 * top_margin) + params->min_porch)) + interlace));
348
349 print_value(7, "[H PERIOD EST (ps)]", h_period_est);
350
351
352 /* 8. Find the number of lines in V sync + back porch:
353 *
354 * [V SYNC+BP] = ROUND(([MIN VSYNC+BP]/[H PERIOD EST]),0)
355 *
356 * But recall that h_period_est is in psec. So multiply by 1000000.
357 */
358
359 vsync_plus_bp = DIVIDE(params->min_vsbp * 1000000, h_period_est);
360
361 print_value(8, "[V SYNC+BP]", vsync_plus_bp);
362
363
364 /* 9. Find the number of lines in V back porch alone:
365 *
366 * [V BACK PORCH] = [V SYNC+BP] - [V SYNC RND]
367 *
368 * XXX is "[V SYNC RND]" a typo? should be [V SYNC RQD]?
369 */
370
371 v_back_porch = vsync_plus_bp - params->vsync_rqd;
372
373 print_value(9, "[V BACK PORCH]", v_back_porch);
374
375
376 /* 10. Find the total number of lines in Vertical field period:
377 *
378 * [TOTAL V LINES] = [V LINES RND] + [TOP MARGIN (LINES)] +
379 * [BOT MARGIN (LINES)] + [V SYNC+BP] + [INTERLACE] +
380 * [MIN PORCH RND]
381 */
382
383 total_v_lines = v_lines + top_margin + bottom_margin + vsync_plus_bp +
384 interlace + params->min_porch;
385
386 print_value(10, "[TOTAL V LINES]", total_v_lines);
387
388
389 /* 11. Estimate the Vertical field frequency:
390 *
391 * [V FIELD RATE EST] = 1 / [H PERIOD EST] / [TOTAL V LINES] * 1000000
392 *
393 * Again, we want to pre multiply by 10^9 to convert for nsec, thereby
394 * making it usable in integer math.
395 *
396 * So we get:
397 *
398 * [V FIELD RATE EST] = 1000000000 / [H PERIOD EST] / [TOTAL V LINES]
399 *
400 * This is all scaled to get the result in uHz. Again, we're trying to
401 * minimize error propagation.
402 */
403 v_field_est = DIVIDE(DIVIDE(1000000000000000ULL, h_period_est),
404 total_v_lines);
405
406 print_value(11, "[V FIELD RATE EST(uHz)]", v_field_est);
407
408
409 /* 12. Find the actual horizontal period:
410 *
411 * [H PERIOD] = [H PERIOD EST] / ([V FIELD RATE RQD] / [V FIELD RATE EST])
412 */
413
414 h_period = DIVIDE(h_period_est * v_field_est, v_field_rqd * 1000);
415
416 print_value(12, "[H PERIOD(ps)]", h_period);
417
418
419 /* 13. Find the actual Vertical field frequency:
420 *
421 * [V FIELD RATE] = 1 / [H PERIOD] / [TOTAL V LINES] * 1000000
422 *
423 * And again, we convert to nsec ahead of time, giving us:
424 *
425 * [V FIELD RATE] = 1000000 / [H PERIOD] / [TOTAL V LINES]
426 *
427 * And another rescaling back to mHz. Gotta love it.
428 */
429
430 v_field_rate = DIVIDE(1000000000000ULL, h_period * total_v_lines);
431
432 print_value(13, "[V FIELD RATE]", v_field_rate);
433
434
435 /* 14. Find the Vertical frame frequency:
436 *
437 * [V FRAME RATE] = (IF([INT RQD?]="y", [V FIELD RATE]/2, [V FIELD RATE]))
438 *
439 * N.B. that the result here is in mHz.
440 */
441
442 v_frame_rate = (flags & VESAGTF_FLAG_ILACE) ?
443 v_field_rate / 2 : v_field_rate;
444
445 print_value(14, "[V FRAME RATE]", v_frame_rate);
446
447
448 /* 15. Find number of pixels in left margin:
449 * 16. Find number of pixels in right margin:
450 *
451 * [LEFT MARGIN (PIXELS)] = (IF( [MARGINS RQD?]="Y",
452 * (ROUND( ([H PIXELS RND] * [MARGIN%] / 100 /
453 * [CELL GRAN RND]),0)) * [CELL GRAN RND],
454 * 0))
455 *
456 * Again, we deal with margin percentages as PPT (parts per thousand).
457 * And the calculations for left and right are the same.
458 */
459
460 left_margin = right_margin = (flags & VESAGTF_FLAG_MARGINS) ?
461 DIVIDE(DIVIDE(h_pixels * params->margin_ppt, 1000),
462 CELL_GRAN) * CELL_GRAN : 0;
463
464 print_value(15, "[LEFT MARGIN (PIXELS)]", left_margin);
465 print_value(16, "[RIGHT MARGIN (PIXELS)]", right_margin);
466
467
468 /* 17. Find total number of active pixels in image and left and right
469 * margins:
470 *
471 * [TOTAL ACTIVE PIXELS] = [H PIXELS RND] + [LEFT MARGIN (PIXELS)] +
472 * [RIGHT MARGIN (PIXELS)]
473 */
474
475 total_active_pixels = h_pixels + left_margin + right_margin;
476
477 print_value(17, "[TOTAL ACTIVE PIXELS]", total_active_pixels);
478
479
480 /* 18. Find the ideal blanking duty cycle from the blanking duty cycle
481 * equation:
482 *
483 * [IDEAL DUTY CYCLE] = [C'] - ([M']*[H PERIOD]/1000)
484 *
485 * However, we have modified values for [C'] as [256*C'] and
486 * [M'] as [256*M']. Again the idea here is to get good scaling.
487 * We use 256 as the factor to make the math fast.
488 *
489 * Note that this means that we have to scale it appropriately in
490 * later calculations.
491 *
492 * The ending result is that our ideal_duty_cycle is 256000x larger
493 * than the duty cycle used by VESA. But again, this reduces error
494 * propagation.
495 */
496
497 ideal_duty_cycle =
498 ((C_PRIME256(params) * 1000) -
499 (M_PRIME256(params) * h_period / 1000000));
500
501 print_value(18, "[IDEAL DUTY CYCLE]", ideal_duty_cycle);
502
503
504 /* 19. Find the number of pixels in the blanking time to the nearest
505 * double character cell:
506 *
507 * [H BLANK (PIXELS)] = (ROUND(([TOTAL ACTIVE PIXELS] *
508 * [IDEAL DUTY CYCLE] /
509 * (100-[IDEAL DUTY CYCLE]) /
510 * (2*[CELL GRAN RND])), 0))
511 * * (2*[CELL GRAN RND])
512 *
513 * Of course, we adjust to make this rounding work in integer math.
514 */
515
516 h_blank = DIVIDE(DIVIDE(total_active_pixels * ideal_duty_cycle,
517 (256000 * 100ULL) - ideal_duty_cycle),
518 2 * CELL_GRAN) * (2 * CELL_GRAN);
519
520 print_value(19, "[H BLANK (PIXELS)]", h_blank);
521
522
523 /* 20. Find total number of pixels:
524 *
525 * [TOTAL PIXELS] = [TOTAL ACTIVE PIXELS] + [H BLANK (PIXELS)]
526 */
527
528 total_pixels = total_active_pixels + h_blank;
529
530 print_value(20, "[TOTAL PIXELS]", total_pixels);
531
532
533 /* 21. Find pixel clock frequency:
534 *
535 * [PIXEL FREQ] = [TOTAL PIXELS] / [H PERIOD]
536 *
537 * We calculate this in Hz rather than MHz, to get a value that
538 * is usable with integer math. Recall that the [H PERIOD] is in
539 * nsec.
540 */
541
542 pixel_freq = DIVIDE(total_pixels * 1000000, DIVIDE(h_period, 1000));
543
544 print_value(21, "[PIXEL FREQ]", pixel_freq);
545
546
547 /* 22. Find horizontal frequency:
548 *
549 * [H FREQ] = 1000 / [H PERIOD]
550 *
551 * I've ifdef'd this out, because we don't need it for any of
552 * our calculations.
553 * We calculate this in Hz rather than kHz, to avoid rounding
554 * errors. Recall that the [H PERIOD] is in usec.
555 */
556
557 #ifdef GTFDEBUG
558 h_freq = 1000000000 / h_period;
559
560 print_value(22, "[H FREQ]", h_freq);
561 #endif
562
563
564
565 /* Stage 1 computations are now complete; I should really pass
566 the results to another function and do the Stage 2
567 computations, but I only need a few more values so I'll just
568 append the computations here for now */
569
570
571
572 /* 17. Find the number of pixels in the horizontal sync period:
573 *
574 * [H SYNC (PIXELS)] =(ROUND(([H SYNC%] / 100 * [TOTAL PIXELS] /
575 * [CELL GRAN RND]),0))*[CELL GRAN RND]
576 *
577 * Rewriting for integer math:
578 *
579 * [H SYNC (PIXELS)]=(ROUND((H SYNC%] * [TOTAL PIXELS] / 100 /
580 * [CELL GRAN RND),0))*[CELL GRAN RND]
581 */
582
583 h_sync = DIVIDE(((params->hsync_pct * total_pixels) / 100), CELL_GRAN) *
584 CELL_GRAN;
585
586 print_value(17, "[H SYNC (PIXELS)]", h_sync);
587
588
589 /* 18. Find the number of pixels in the horizontal front porch period:
590 *
591 * [H FRONT PORCH (PIXELS)] = ([H BLANK (PIXELS)]/2)-[H SYNC (PIXELS)]
592 *
593 * Note that h_blank is always an even number of characters (i.e.
594 * h_blank % (CELL_GRAN * 2) == 0)
595 */
596
597 h_front_porch = (h_blank / 2) - h_sync;
598
599 print_value(18, "[H FRONT PORCH (PIXELS)]", h_front_porch);
600
601
602 /* 36. Find the number of lines in the odd front porch period:
603 *
604 * [V ODD FRONT PORCH(LINES)]=([MIN PORCH RND]+[INTERLACE])
605 *
606 * Adjusting for the fact that the interlace is scaled:
607 *
608 * [V ODD FRONT PORCH(LINES)]=(([MIN PORCH RND] * 2) + [2*INTERLACE]) / 2
609 */
610
611 v_odd_front_porch_lines = ((2 * params->min_porch) + interlace) / 2;
612
613 print_value(36, "[V ODD FRONT PORCH(LINES)]", v_odd_front_porch_lines);
614
615
616 /* finally, pack the results in the mode struct */
617
618 vmp->hsync_start = h_pixels + h_front_porch;
619 vmp->hsync_end = vmp->hsync_start + h_sync;
620 vmp->htotal = total_pixels;
621 vmp->hdisplay = h_pixels;
622
623 vmp->vsync_start = v_lines + v_odd_front_porch_lines;
624 vmp->vsync_end = vmp->vsync_start + params->vsync_rqd;
625 vmp->vtotal = total_v_lines;
626 vmp->vdisplay = v_lines;
627
628 vmp->dot_clock = pixel_freq;
629
630 }
631
632 void
vesagtf_mode(unsigned x,unsigned y,unsigned refresh,struct videomode * vmp)633 vesagtf_mode(unsigned x, unsigned y, unsigned refresh, struct videomode *vmp)
634 {
635 struct vesagtf_params params;
636
637 params.margin_ppt = VESAGTF_MARGIN_PPT;
638 params.min_porch = VESAGTF_MIN_PORCH;
639 params.vsync_rqd = VESAGTF_VSYNC_RQD;
640 params.hsync_pct = VESAGTF_HSYNC_PCT;
641 params.min_vsbp = VESAGTF_MIN_VSBP;
642 params.M = VESAGTF_M;
643 params.C = VESAGTF_C;
644 params.K = VESAGTF_K;
645 params.J = VESAGTF_J;
646
647 vesagtf_mode_params(x, y, refresh, ¶ms, 0, vmp);
648 }
649
650 /*
651 * The tidbit here is so that you can compile this file as a
652 * standalone user program to generate X11 modelines using VESA GTF.
653 * This also allows for testing of the code itself, without
654 * necessitating a full kernel recompile.
655 */
656
657 /* print_xf86_mode() - print the XFree86 modeline, given mode timings. */
658
659 #if 0
660 #ifndef _KERNEL
661 void
662 print_xf86_mode (struct videomode *vmp)
663 {
664 float vf, hf;
665
666 hf = 1000.0 * vmp->dot_clock / vmp->htotal;
667 vf = 1.0 * hf / vmp->vtotal;
668
669 printf("\n");
670 printf(" # %dx%d @ %.2f Hz (GTF) hsync: %.2f kHz; pclk: %.2f MHz\n",
671 vmp->hdisplay, vmp->vdisplay, vf, hf, vmp->dot_clock / 1000.0);
672
673 printf(" Modeline \"%dx%d_%.2f\" %.2f"
674 " %d %d %d %d"
675 " %d %d %d %d"
676 " -HSync +Vsync\n\n",
677 vmp->hdisplay, vmp->vdisplay, vf, (vmp->dot_clock / 1000.0),
678 vmp->hdisplay, vmp->hsync_start, vmp->hsync_end, vmp->htotal,
679 vmp->vdisplay, vmp->vsync_start, vmp->vsync_end, vmp->vtotal);
680 }
681
682 int
683 main (int argc, char *argv[])
684 {
685 struct videomode m;
686
687 if (argc != 4) {
688 printf("usage: %s x y refresh\n", argv[0]);
689 exit(1);
690 }
691
692 vesagtf_mode(atoi(argv[1]), atoi(argv[2]), atoi(argv[3]), &m);
693
694 print_xf86_mode(&m);
695
696 return 0;
697
698 }
699 #endif
700 #endif
701