1/*	$NetBSD: vesagtf.h,v 1.1 2006/05/11 01:49:53 gdamore 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#ifndef _DEV_VIDEOMODE_VESAGTF_H
35#define _DEV_VIDEOMODE_VESAGTF_H
36
37/*
38 * Use VESA GTF formula to generate a monitor mode, given resolution and
39 * refresh rates.
40 */
41
42struct vesagtf_params {
43	unsigned	margin_ppt;	/* vertical margin size, percent * 10
44					 * think parts-per-thousand */
45	unsigned	min_porch;	/* minimum front porch */
46	unsigned	vsync_rqd;	/* width of vsync in lines */
47	unsigned	hsync_pct;	/* hsync as % of total width */
48	unsigned	min_vsbp;	/* minimum vsync + back porch (usec) */
49	unsigned	M;		/* blanking formula gradient */
50	unsigned	C;		/* blanking formula offset */
51	unsigned	K;		/* blanking formula scaling factor */
52	unsigned	J;		/* blanking formula scaling factor */
53};
54
55/*
56 * Default values to use for params.
57 */
58#define	VESAGTF_MARGIN_PPT	18	/* 1.8% */
59#define	VESAGTF_MIN_PORCH	1	/* minimum front porch */
60#define	VESAGTF_VSYNC_RQD	3	/* vsync width in lines */
61#define	VESAGTF_HSYNC_PCT	8	/* width of hsync % of total line */
62#define	VESAGTF_MIN_VSBP	550	/* min vsync + back porch (usec) */
63#define	VESAGTF_M		600	/* blanking formula gradient */
64#define	VESAGTF_C		40	/* blanking formula offset */
65#define	VESAGTF_K		128	/* blanking formula scaling factor */
66#define	VESAGTF_J		20	/* blanking formula scaling factor */
67
68/*
69 * Use VESA GTF formula to generate monitor timings.  Assumes default
70 * GTF parameters, non-interlaced, and no margins.
71 */
72void vesagtf_mode(unsigned x, unsigned y, unsigned refresh,
73    struct videomode *);
74
75/*
76 * A more complete version, in case we ever want to use alternate GTF
77 * parameters.  EDID 1.3 allows for "secondary GTF parameters".
78 */
79void vesagtf_mode_params(unsigned x, unsigned y, unsigned refresh,
80    struct vesagtf_params *, int flags, struct videomode *);
81
82#define	VESAGTF_FLAG_ILACE	0x0001		/* use interlace */
83#define	VESAGTF_FLAG_MARGINS	0x0002		/* use margins */
84
85#endif /* _DEV_VIDEOMODE_VESAGTF_H */
86