1/* gtf.c  Generate mode timings using the GTF Timing Standard
2 *
3 * gcc gtf.c -o gtf -lm -Wall
4 *
5 * Copyright (c) 2001, Andy Ritger  aritger@nvidia.com
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * o Redistributions of source code must retain the above copyright
13 *   notice, this list of conditions and the following disclaimer.
14 * o Redistributions in binary form must reproduce the above copyright
15 *   notice, this list of conditions and the following disclaimer
16 *   in the documentation and/or other materials provided with the
17 *   distribution.
18 * o Neither the name of NVIDIA nor the names of its contributors
19 *   may be used to endorse or promote products derived from this
20 *   software without specific prior written permission.
21 *
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
24 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT
25 * NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
26 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
27 * THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
28 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
29 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
30 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
31 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
33 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
34 * POSSIBILITY OF SUCH DAMAGE.
35 *
36 *
37 *
38 * This program is based on the Generalized Timing Formula(GTF TM)
39 * Standard Version: 1.0, Revision: 1.0
40 *
41 * The GTF Document contains the following Copyright information:
42 *
43 * Copyright (c) 1994, 1995, 1996 - Video Electronics Standards
44 * Association. Duplication of this document within VESA member
45 * companies for review purposes is permitted. All other rights
46 * reserved.
47 *
48 * While every precaution has been taken in the preparation
49 * of this standard, the Video Electronics Standards Association and
50 * its contributors assume no responsibility for errors or omissions,
51 * and make no warranties, expressed or implied, of functionality
52 * of suitability for any purpose. The sample code contained within
53 * this standard may be used without restriction.
54 *
55 *
56 *
57 * The GTF EXCEL(TM) SPREADSHEET, a sample (and the definitive)
58 * implementation of the GTF Timing Standard, is available at:
59 *
60 * ftp://ftp.vesa.org/pub/GTF/GTF_V1R1.xls
61 *
62 *
63 *
64 * This program takes a desired resolution and vertical refresh rate,
65 * and computes mode timings according to the GTF Timing Standard.
66 * These mode timings can then be formatted as an XServer modeline
67 * or a mode description for use by fbset(8).
68 *
69 *
70 *
71 * NOTES:
72 *
73 * The GTF allows for computation of "margins" (the visible border
74 * surrounding the addressable video); on most non-overscan type
75 * systems, the margin period is zero.  I've implemented the margin
76 * computations but not enabled it because 1) I don't really have
77 * any experience with this, and 2) neither XServer modelines nor
78 * fbset fb.modes provide an obvious way for margin timings to be
79 * included in their mode descriptions (needs more investigation).
80 *
81 * The GTF provides for computation of interlaced mode timings;
82 * I've implemented the computations but not enabled them, yet.
83 * I should probably enable and test this at some point.
84 *
85 *
86 *
87 * TODO:
88 *
89 * o Add support for interlaced modes.
90 *
91 * o Implement the other portions of the GTF: compute mode timings
92 *   given either the desired pixel clock or the desired horizontal
93 *   frequency.
94 *
95 * o It would be nice if this were more general purpose to do things
96 *   outside the scope of the GTF: like generate double scan mode
97 *   timings, for example.
98 *
99 * o Printing digits to the right of the decimal point when the
100 *   digits are 0 annoys me.
101 *
102 * o Error checking.
103 *
104 */
105
106#ifdef HAVE_XORG_CONFIG_H
107# include <xorg-config.h>
108#endif
109
110#include <stdio.h>
111#include <stdlib.h>
112#include <string.h>
113#include <math.h>
114
115#define MARGIN_PERCENT    1.8   /* % of active vertical image                */
116#define CELL_GRAN         8.0   /* assumed character cell granularity        */
117#define MIN_PORCH         1     /* minimum front porch                       */
118#define V_SYNC_RQD        3     /* width of vsync in lines                   */
119#define H_SYNC_PERCENT    8.0   /* width of hsync as % of total line         */
120#define MIN_VSYNC_PLUS_BP 550.0 /* min time of vsync + back porch (microsec) */
121#define M                 600.0 /* blanking formula gradient                 */
122#define C                 40.0  /* blanking formula offset                   */
123#define K                 128.0 /* blanking formula scaling factor           */
124#define J                 20.0  /* blanking formula scaling factor           */
125
126/* C' and M' are part of the Blanking Duty Cycle computation */
127
128#define C_PRIME           (((C - J) * K/256.0) + J)
129#define M_PRIME           (K/256.0 * M)
130
131
132/* struct definitions */
133
134typedef struct __mode
135{
136    int hr, hss, hse, hfl;
137    int vr, vss, vse, vfl;
138    float pclk, h_freq, v_freq;
139} mode;
140
141
142typedef struct __options
143{
144    int x, y;
145    int xorgmode, fbmode;
146    float v_freq;
147} options;
148
149
150
151
152/* prototypes */
153
154void print_value(int n, char *name, float val);
155void print_xf86_mode (mode *m);
156void print_fb_mode (mode *m);
157mode *vert_refresh (int h_pixels, int v_lines, float freq,
158                    int interlaced, int margins);
159options *parse_command_line (int argc, char *argv[]);
160
161
162
163
164/*
165 * print_value() - print the result of the named computation; this is
166 * useful when comparing against the GTF EXCEL spreadsheet.
167 */
168
169int global_verbose = 0;
170
171void print_value(int n, char *name, float val)
172{
173    if (global_verbose) {
174        printf("%2d: %-27s: %15f\n", n, name, val);
175    }
176}
177
178
179
180/* print_xf86_mode() - print the XServer modeline, given mode timings. */
181
182void print_xf86_mode (mode *m)
183{
184    printf ("\n");
185    printf ("  # %dx%d @ %.2f Hz (GTF) hsync: %.2f kHz; pclk: %.2f MHz\n",
186            m->hr, m->vr, m->v_freq, m->h_freq, m->pclk);
187
188    printf ("  Modeline \"%dx%d_%.2f\"  %.2f"
189            "  %d %d %d %d"
190            "  %d %d %d %d"
191            "  -HSync +Vsync\n\n",
192            m->hr, m->vr, m->v_freq, m->pclk,
193            m->hr, m->hss, m->hse, m->hfl,
194            m->vr, m->vss, m->vse, m->vfl);
195
196}
197
198
199
200/*
201 * print_fb_mode() - print a mode description in fbset(8) format;
202 * see the fb.modes(8) manpage.  The timing description used in
203 * this is rather odd; they use "left and right margin" to refer
204 * to the portion of the hblank before and after the sync pulse
205 * by conceptually wrapping the portion of the blank after the pulse
206 * to infront of the visible region; ie:
207 *
208 *
209 * Timing description I'm accustomed to:
210 *
211 *
212 *
213 *     <--------1--------> <--2--> <--3--> <--4-->
214 *                                _________
215 *    |-------------------|_______|       |_______
216 *
217 *                        R       SS      SE     FL
218 *
219 * 1: visible image
220 * 2: blank before sync (aka front porch)
221 * 3: sync pulse
222 * 4: blank after sync (aka back porch)
223 * R: Resolution
224 * SS: Sync Start
225 * SE: Sync End
226 * FL: Frame Length
227 *
228 *
229 * But the fb.modes format is:
230 *
231 *
232 *    <--4--> <--------1--------> <--2--> <--3-->
233 *                                       _________
234 *    _______|-------------------|_______|       |
235 *
236 * The fb.modes(8) manpage refers to <4> and <2> as the left and
237 * right "margin" (as well as upper and lower margin in the vertical
238 * direction) -- note that this has nothing to do with the term
239 * "margin" used in the GTF Timing Standard.
240 *
241 * XXX always prints the 32 bit mode -- should I provide a command
242 * line option to specify the bpp?  It's simple enough for a user
243 * to edit the mode description after it's generated.
244 */
245
246void print_fb_mode (mode *m)
247{
248    printf ("\n");
249    printf ("mode \"%dx%d %.2fHz 32bit (GTF)\"\n",
250            m->hr, m->vr, m->v_freq);
251    printf ("    # PCLK: %.2f MHz, H: %.2f kHz, V: %.2f Hz\n",
252            m->pclk, m->h_freq, m->v_freq);
253    printf ("    geometry %d %d %d %d 32\n",
254            m->hr, m->vr, m->hr, m->vr);
255    printf ("    timings %d %d %d %d %d %d %d\n",
256            (int) rint(1000000.0/m->pclk),/* pixclock in picoseconds */
257            m->hfl - m->hse,              /* left margin (in pixels) */
258            m->hss - m->hr,               /* right margin (in pixels) */
259            m->vfl - m->vse,              /* upper margin (in pixel lines) */
260            m->vss - m->vr,               /* lower margin (in pixel lines) */
261            m->hse - m->hss,              /* horizontal sync length (pixels) */
262            m->vse - m->vss);             /* vert sync length (pixel lines) */
263    printf ("    hsync low\n");
264    printf ("    vsync high\n");
265    printf ("endmode\n\n");
266
267}
268
269
270
271
272/*
273 * vert_refresh() - as defined by the GTF Timing Standard, compute the
274 * Stage 1 Parameters using the vertical refresh frequency.  In other
275 * words: input a desired resolution and desired refresh rate, and
276 * output the GTF mode timings.
277 *
278 * XXX All the code is in place to compute interlaced modes, but I don't
279 * feel like testing it right now.
280 *
281 * XXX margin computations are implemented but not tested (nor used by
282 * XServer of fbset mode descriptions, from what I can tell).
283 */
284
285mode *vert_refresh (int h_pixels, int v_lines, float freq,
286                    int interlaced, int margins)
287{
288    float h_pixels_rnd;
289    float v_lines_rnd;
290    float v_field_rate_rqd;
291    float top_margin;
292    float bottom_margin;
293    float interlace;
294    float h_period_est;
295    float vsync_plus_bp;
296    float v_back_porch;
297    float total_v_lines;
298    float v_field_rate_est;
299    float h_period;
300    float v_field_rate;
301    float v_frame_rate;
302    float left_margin;
303    float right_margin;
304    float total_active_pixels;
305    float ideal_duty_cycle;
306    float h_blank;
307    float total_pixels;
308    float pixel_freq;
309    float h_freq;
310
311    float h_sync;
312    float h_front_porch;
313    float v_odd_front_porch_lines;
314
315    mode *m = (mode*) malloc (sizeof (mode));
316
317
318    /*  1. In order to give correct results, the number of horizontal
319     *  pixels requested is first processed to ensure that it is divisible
320     *  by the character size, by rounding it to the nearest character
321     *  cell boundary:
322     *
323     *  [H PIXELS RND] = ((ROUND([H PIXELS]/[CELL GRAN RND],0))*[CELLGRAN RND])
324     */
325
326    h_pixels_rnd = rint((float) h_pixels / CELL_GRAN) * CELL_GRAN;
327
328    print_value(1, "[H PIXELS RND]", h_pixels_rnd);
329
330
331    /*  2. If interlace is requested, the number of vertical lines assumed
332     *  by the calculation must be halved, as the computation calculates
333     *  the number of vertical lines per field. In either case, the
334     *  number of lines is rounded to the nearest integer.
335     *
336     *  [V LINES RND] = IF([INT RQD?]="y", ROUND([V LINES]/2,0),
337     *                                     ROUND([V LINES],0))
338     */
339
340    v_lines_rnd = interlaced ?
341            rint((float) v_lines) / 2.0 :
342            rint((float) v_lines);
343
344    print_value(2, "[V LINES RND]", v_lines_rnd);
345
346
347    /*  3. Find the frame rate required:
348     *
349     *  [V FIELD RATE RQD] = IF([INT RQD?]="y", [I/P FREQ RQD]*2,
350     *                                          [I/P FREQ RQD])
351     */
352
353    v_field_rate_rqd = interlaced ? (freq * 2.0) : (freq);
354
355    print_value(3, "[V FIELD RATE RQD]", v_field_rate_rqd);
356
357
358    /*  4. Find number of lines in Top margin:
359     *
360     *  [TOP MARGIN (LINES)] = IF([MARGINS RQD?]="Y",
361     *          ROUND(([MARGIN%]/100*[V LINES RND]),0),
362     *          0)
363     */
364
365    top_margin = margins ? rint(MARGIN_PERCENT / 100.0 * v_lines_rnd) : (0.0);
366
367    print_value(4, "[TOP MARGIN (LINES)]", top_margin);
368
369
370    /*  5. Find number of lines in Bottom margin:
371     *
372     *  [BOT MARGIN (LINES)] = IF([MARGINS RQD?]="Y",
373     *          ROUND(([MARGIN%]/100*[V LINES RND]),0),
374     *          0)
375     */
376
377    bottom_margin = margins ? rint(MARGIN_PERCENT/100.0 * v_lines_rnd) : (0.0);
378
379    print_value(5, "[BOT MARGIN (LINES)]", bottom_margin);
380
381
382    /*  6. If interlace is required, then set variable [INTERLACE]=0.5:
383     *
384     *  [INTERLACE]=(IF([INT RQD?]="y",0.5,0))
385     */
386
387    interlace = interlaced ? 0.5 : 0.0;
388
389    print_value(6, "[INTERLACE]", interlace);
390
391
392    /*  7. Estimate the Horizontal period
393     *
394     *  [H PERIOD EST] = ((1/[V FIELD RATE RQD]) - [MIN VSYNC+BP]/1000000) /
395     *                    ([V LINES RND] + (2*[TOP MARGIN (LINES)]) +
396     *                     [MIN PORCH RND]+[INTERLACE]) * 1000000
397     */
398
399    h_period_est = (((1.0/v_field_rate_rqd) - (MIN_VSYNC_PLUS_BP/1000000.0))
400                    / (v_lines_rnd + (2*top_margin) + MIN_PORCH + interlace)
401                    * 1000000.0);
402
403    print_value(7, "[H PERIOD EST]", h_period_est);
404
405
406    /*  8. Find the number of lines in V sync + back porch:
407     *
408     *  [V SYNC+BP] = ROUND(([MIN VSYNC+BP]/[H PERIOD EST]),0)
409     */
410
411    vsync_plus_bp = rint(MIN_VSYNC_PLUS_BP/h_period_est);
412
413    print_value(8, "[V SYNC+BP]", vsync_plus_bp);
414
415
416    /*  9. Find the number of lines in V back porch alone:
417     *
418     *  [V BACK PORCH] = [V SYNC+BP] - [V SYNC RND]
419     *
420     *  XXX is "[V SYNC RND]" a typo? should be [V SYNC RQD]?
421     */
422
423    v_back_porch = vsync_plus_bp - V_SYNC_RQD;
424
425    print_value(9, "[V BACK PORCH]", v_back_porch);
426
427
428    /*  10. Find the total number of lines in Vertical field period:
429     *
430     *  [TOTAL V LINES] = [V LINES RND] + [TOP MARGIN (LINES)] +
431     *                    [BOT MARGIN (LINES)] + [V SYNC+BP] + [INTERLACE] +
432     *                    [MIN PORCH RND]
433     */
434
435    total_v_lines = v_lines_rnd + top_margin + bottom_margin + vsync_plus_bp +
436        interlace + MIN_PORCH;
437
438    print_value(10, "[TOTAL V LINES]", total_v_lines);
439
440
441    /*  11. Estimate the Vertical field frequency:
442     *
443     *  [V FIELD RATE EST] = 1 / [H PERIOD EST] / [TOTAL V LINES] * 1000000
444     */
445
446    v_field_rate_est = 1.0 / h_period_est / total_v_lines * 1000000.0;
447
448    print_value(11, "[V FIELD RATE EST]", v_field_rate_est);
449
450
451    /*  12. Find the actual horizontal period:
452     *
453     *  [H PERIOD] = [H PERIOD EST] / ([V FIELD RATE RQD] / [V FIELD RATE EST])
454     */
455
456    h_period = h_period_est / (v_field_rate_rqd / v_field_rate_est);
457
458    print_value(12, "[H PERIOD]", h_period);
459
460
461    /*  13. Find the actual Vertical field frequency:
462     *
463     *  [V FIELD RATE] = 1 / [H PERIOD] / [TOTAL V LINES] * 1000000
464     */
465
466    v_field_rate = 1.0 / h_period / total_v_lines * 1000000.0;
467
468    print_value(13, "[V FIELD RATE]", v_field_rate);
469
470
471    /*  14. Find the Vertical frame frequency:
472     *
473     *  [V FRAME RATE] = (IF([INT RQD?]="y", [V FIELD RATE]/2, [V FIELD RATE]))
474     */
475
476    v_frame_rate = interlaced ? v_field_rate / 2.0 : v_field_rate;
477
478    print_value(14, "[V FRAME RATE]", v_frame_rate);
479
480
481    /*  15. Find number of pixels in left margin:
482     *
483     *  [LEFT MARGIN (PIXELS)] = (IF( [MARGINS RQD?]="Y",
484     *          (ROUND( ([H PIXELS RND] * [MARGIN%] / 100 /
485     *                   [CELL GRAN RND]),0)) * [CELL GRAN RND],
486     *          0))
487     */
488
489    left_margin = margins ?
490        rint(h_pixels_rnd * MARGIN_PERCENT / 100.0 / CELL_GRAN) * CELL_GRAN :
491        0.0;
492
493    print_value(15, "[LEFT MARGIN (PIXELS)]", left_margin);
494
495
496    /*  16. Find number of pixels in right margin:
497     *
498     *  [RIGHT MARGIN (PIXELS)] = (IF( [MARGINS RQD?]="Y",
499     *          (ROUND( ([H PIXELS RND] * [MARGIN%] / 100 /
500     *                   [CELL GRAN RND]),0)) * [CELL GRAN RND],
501     *          0))
502     */
503
504    right_margin = margins ?
505        rint(h_pixels_rnd * MARGIN_PERCENT / 100.0 / CELL_GRAN) * CELL_GRAN :
506        0.0;
507
508    print_value(16, "[RIGHT MARGIN (PIXELS)]", right_margin);
509
510
511    /*  17. Find total number of active pixels in image and left and right
512     *  margins:
513     *
514     *  [TOTAL ACTIVE PIXELS] = [H PIXELS RND] + [LEFT MARGIN (PIXELS)] +
515     *                          [RIGHT MARGIN (PIXELS)]
516     */
517
518    total_active_pixels = h_pixels_rnd + left_margin + right_margin;
519
520    print_value(17, "[TOTAL ACTIVE PIXELS]", total_active_pixels);
521
522
523    /*  18. Find the ideal blanking duty cycle from the blanking duty cycle
524     *  equation:
525     *
526     *  [IDEAL DUTY CYCLE] = [C'] - ([M']*[H PERIOD]/1000)
527     */
528
529    ideal_duty_cycle = C_PRIME - (M_PRIME * h_period / 1000.0);
530
531    print_value(18, "[IDEAL DUTY CYCLE]", ideal_duty_cycle);
532
533
534    /*  19. Find the number of pixels in the blanking time to the nearest
535     *  double character cell:
536     *
537     *  [H BLANK (PIXELS)] = (ROUND(([TOTAL ACTIVE PIXELS] *
538     *                               [IDEAL DUTY CYCLE] /
539     *                               (100-[IDEAL DUTY CYCLE]) /
540     *                               (2*[CELL GRAN RND])), 0))
541     *                       * (2*[CELL GRAN RND])
542     */
543
544    h_blank = rint(total_active_pixels *
545                   ideal_duty_cycle /
546                   (100.0 - ideal_duty_cycle) /
547                   (2.0 * CELL_GRAN)) * (2.0 * CELL_GRAN);
548
549    print_value(19, "[H BLANK (PIXELS)]", h_blank);
550
551
552    /*  20. Find total number of pixels:
553     *
554     *  [TOTAL PIXELS] = [TOTAL ACTIVE PIXELS] + [H BLANK (PIXELS)]
555     */
556
557    total_pixels = total_active_pixels + h_blank;
558
559    print_value(20, "[TOTAL PIXELS]", total_pixels);
560
561
562    /*  21. Find pixel clock frequency:
563     *
564     *  [PIXEL FREQ] = [TOTAL PIXELS] / [H PERIOD]
565     */
566
567    pixel_freq = total_pixels / h_period;
568
569    print_value(21, "[PIXEL FREQ]", pixel_freq);
570
571
572    /*  22. Find horizontal frequency:
573     *
574     *  [H FREQ] = 1000 / [H PERIOD]
575     */
576
577    h_freq = 1000.0 / h_period;
578
579    print_value(22, "[H FREQ]", h_freq);
580
581
582
583    /* Stage 1 computations are now complete; I should really pass
584       the results to another function and do the Stage 2
585       computations, but I only need a few more values so I'll just
586       append the computations here for now */
587
588
589
590    /*  17. Find the number of pixels in the horizontal sync period:
591     *
592     *  [H SYNC (PIXELS)] =(ROUND(([H SYNC%] / 100 * [TOTAL PIXELS] /
593     *                             [CELL GRAN RND]),0))*[CELL GRAN RND]
594     */
595
596    h_sync = rint(H_SYNC_PERCENT/100.0 * total_pixels / CELL_GRAN) * CELL_GRAN;
597
598    print_value(17, "[H SYNC (PIXELS)]", h_sync);
599
600
601    /*  18. Find the number of pixels in the horizontal front porch period:
602     *
603     *  [H FRONT PORCH (PIXELS)] = ([H BLANK (PIXELS)]/2)-[H SYNC (PIXELS)]
604     */
605
606    h_front_porch = (h_blank / 2.0) - h_sync;
607
608    print_value(18, "[H FRONT PORCH (PIXELS)]", h_front_porch);
609
610
611    /*  36. Find the number of lines in the odd front porch period:
612     *
613     *  [V ODD FRONT PORCH(LINES)]=([MIN PORCH RND]+[INTERLACE])
614     */
615
616    v_odd_front_porch_lines = MIN_PORCH + interlace;
617
618    print_value(36, "[V ODD FRONT PORCH(LINES)]", v_odd_front_porch_lines);
619
620
621    /* finally, pack the results in the mode struct */
622
623    m->hr  = (int) (h_pixels_rnd);
624    m->hss = (int) (h_pixels_rnd + h_front_porch);
625    m->hse = (int) (h_pixels_rnd + h_front_porch + h_sync);
626    m->hfl = (int) (total_pixels);
627
628    m->vr  = (int) (v_lines_rnd);
629    m->vss = (int) (v_lines_rnd + v_odd_front_porch_lines);
630    m->vse = (int) (int) (v_lines_rnd + v_odd_front_porch_lines + V_SYNC_RQD);
631    m->vfl = (int) (total_v_lines);
632
633    m->pclk   = pixel_freq;
634    m->h_freq = h_freq;
635    m->v_freq = freq;
636
637    return m;
638
639}
640
641
642
643
644/*
645 * parse_command_line() - parse the command line and return an
646 * alloced structure containing the results.  On error print usage
647 * and return NULL.
648 */
649
650options *parse_command_line (int argc, char *argv[])
651{
652    int n;
653
654    options *o = (options *) calloc (1, sizeof (options));
655
656    if (argc < 4) goto bad_option;
657
658    o->x = atoi (argv[1]);
659    o->y = atoi (argv[2]);
660    o->v_freq = atof (argv[3]);
661
662    /* XXX should check for errors in the above */
663
664    n = 4;
665
666    while (n < argc) {
667        if ((strcmp (argv[n], "-v") == 0) ||
668            (strcmp (argv[n], "--verbose") == 0)) {
669            global_verbose = 1;
670        } else if ((strcmp (argv[n], "-f") == 0) ||
671                   (strcmp (argv[n], "--fbmode") == 0)) {
672            o->fbmode = 1;
673        } else if ((strcmp (argv[n], "-x") == 0) ||
674		   (strcmp (argv[n], "--xorgmode") == 0) ||
675                   (strcmp (argv[n], "--xf86mode") == 0)) {
676            o->xorgmode = 1;
677        } else {
678            goto bad_option;
679        }
680
681        n++;
682    }
683
684    /* if neither xorgmode nor fbmode were requested, default to
685       xorgmode */
686
687    if (!o->fbmode && !o->xorgmode) o->xorgmode = 1;
688
689    return o;
690
691 bad_option:
692
693    fprintf (stderr, "\n");
694    fprintf (stderr, "usage: %s x y refresh [-v|--verbose] "
695             "[-f|--fbmode] [-x|--xorgmode]\n", argv[0]);
696
697    fprintf (stderr, "\n");
698
699    fprintf (stderr, "            x : the desired horizontal "
700             "resolution (required)\n");
701    fprintf (stderr, "            y : the desired vertical "
702             "resolution (required)\n");
703    fprintf (stderr, "      refresh : the desired refresh "
704             "rate (required)\n");
705    fprintf (stderr, " -v|--verbose : enable verbose printouts "
706             "(traces each step of the computation)\n");
707    fprintf (stderr, "  -f|--fbmode : output an fbset(8)-style mode "
708             "description\n");
709    fprintf (stderr, " -x|--xorgmode : output an "__XSERVERNAME__"-style mode "
710             "description (this is the default\n"
711             "                if no mode description is requested)\n");
712
713    fprintf (stderr, "\n");
714
715    free (o);
716    return NULL;
717
718}
719
720
721
722int main (int argc, char *argv[])
723{
724    mode *m;
725    options *o;
726
727    o = parse_command_line (argc, argv);
728    if (!o) exit (1);
729
730    m = vert_refresh (o->x, o->y, o->v_freq, 0, 0);
731    if (!m) exit (1);
732
733    if (o->xorgmode)
734        print_xf86_mode(m);
735
736    if (o->fbmode)
737        print_fb_mode(m);
738
739    return 0;
740
741}
742