1/*	$NetBSD$	*/
2/*	$FreeBSD$	*/
3
4/*-
5 * Copyright (c) 2006 Itronix Inc.
6 * All rights reserved.
7 *
8 * Written by Garrett D'Amore for Itronix Inc.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 3. The name of Itronix Inc. may not be used to endorse
19 *    or promote products derived from this software without specific
20 *    prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY ITRONIX INC. ``AS IS'' AND ANY EXPRESS
23 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
24 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED.  IN NO EVENT SHALL ITRONIX INC. BE LIABLE FOR ANY
26 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
28 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
29 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
30 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
31 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
32 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33 */
34
35#ifndef _DEV_VIDEOMODE_VESAGTF_H
36#define _DEV_VIDEOMODE_VESAGTF_H
37
38/*
39 * Use VESA GTF formula to generate a monitor mode, given resolution and
40 * refresh rates.
41 */
42
43struct vesagtf_params {
44	unsigned	margin_ppt;	/* vertical margin size, percent * 10
45					 * think parts-per-thousand */
46	unsigned	min_porch;	/* minimum front porch */
47	unsigned	vsync_rqd;	/* width of vsync in lines */
48	unsigned	hsync_pct;	/* hsync as % of total width */
49	unsigned	min_vsbp;	/* minimum vsync + back porch (usec) */
50	unsigned	M;		/* blanking formula gradient */
51	unsigned	C;		/* blanking formula offset */
52	unsigned	K;		/* blanking formula scaling factor */
53	unsigned	J;		/* blanking formula scaling factor */
54};
55
56/*
57 * Default values to use for params.
58 */
59#define	VESAGTF_MARGIN_PPT	18	/* 1.8% */
60#define	VESAGTF_MIN_PORCH	1	/* minimum front porch */
61#define	VESAGTF_VSYNC_RQD	3	/* vsync width in lines */
62#define	VESAGTF_HSYNC_PCT	8	/* width of hsync % of total line */
63#define	VESAGTF_MIN_VSBP	550	/* min vsync + back porch (usec) */
64#define	VESAGTF_M		600	/* blanking formula gradient */
65#define	VESAGTF_C		40	/* blanking formula offset */
66#define	VESAGTF_K		128	/* blanking formula scaling factor */
67#define	VESAGTF_J		20	/* blanking formula scaling factor */
68
69/*
70 * Use VESA GTF formula to generate monitor timings.  Assumes default
71 * GTF parameters, non-interlaced, and no margins.
72 */
73void vesagtf_mode(unsigned x, unsigned y, unsigned refresh,
74    struct videomode *);
75
76/*
77 * A more complete version, in case we ever want to use alternate GTF
78 * parameters.  EDID 1.3 allows for "secondary GTF parameters".
79 */
80void vesagtf_mode_params(unsigned x, unsigned y, unsigned refresh,
81    struct vesagtf_params *, int flags, struct videomode *);
82
83#define	VESAGTF_FLAG_ILACE	0x0001		/* use interlace */
84#define	VESAGTF_FLAG_MARGINS	0x0002		/* use margins */
85
86#endif /* _DEV_VIDEOMODE_VESAGTF_H */
87