/*      $NetBSD: vesagtf.h,v 1.1 2006/05/11 01:49:53 gdamore Exp $      */

/*-
* Copyright (c) 2006 Itronix Inc.
* All rights reserved.
*
* Written by Garrett D'Amore for Itronix Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
* 3. The name of Itronix Inc. may not be used to endorse
*    or promote products derived from this software without specific
*    prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY ITRONIX INC. ``AS IS'' AND ANY EXPRESS
* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED.  IN NO EVENT SHALL ITRONIX INC. BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
* GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#ifndef _DEV_VIDEOMODE_VESAGTF_H
#define _DEV_VIDEOMODE_VESAGTF_H

/*
* Use VESA GTF formula to generate a monitor mode, given resolution and
* refresh rates.
*/

struct vesagtf_params {
       unsigned        margin_ppt;     /* vertical margin size, percent * 10
                                        * think parts-per-thousand */
       unsigned        min_porch;      /* minimum front porch */
       unsigned        vsync_rqd;      /* width of vsync in lines */
       unsigned        hsync_pct;      /* hsync as % of total width */
       unsigned        min_vsbp;       /* minimum vsync + back porch (usec) */
       unsigned        M;              /* blanking formula gradient */
       unsigned        C;              /* blanking formula offset */
       unsigned        K;              /* blanking formula scaling factor */
       unsigned        J;              /* blanking formula scaling factor */
};

/*
* Default values to use for params.
*/
#define VESAGTF_MARGIN_PPT      18      /* 1.8% */
#define VESAGTF_MIN_PORCH       1       /* minimum front porch */
#define VESAGTF_VSYNC_RQD       3       /* vsync width in lines */
#define VESAGTF_HSYNC_PCT       8       /* width of hsync % of total line */
#define VESAGTF_MIN_VSBP        550     /* min vsync + back porch (usec) */
#define VESAGTF_M               600     /* blanking formula gradient */
#define VESAGTF_C               40      /* blanking formula offset */
#define VESAGTF_K               128     /* blanking formula scaling factor */
#define VESAGTF_J               20      /* blanking formula scaling factor */

/*
* Use VESA GTF formula to generate monitor timings.  Assumes default
* GTF parameters, non-interlaced, and no margins.
*/
void vesagtf_mode(unsigned x, unsigned y, unsigned refresh,
   struct videomode *);

/*
* A more complete version, in case we ever want to use alternate GTF
* parameters.  EDID 1.3 allows for "secondary GTF parameters".
*/
void vesagtf_mode_params(unsigned x, unsigned y, unsigned refresh,
   struct vesagtf_params *, int flags, struct videomode *);

#define VESAGTF_FLAG_ILACE      0x0001          /* use interlace */
#define VESAGTF_FLAG_MARGINS    0x0002          /* use margins */

#endif /* _DEV_VIDEOMODE_VESAGTF_H */