sys/dev/videomode/vesagtf.h

   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
  42 struct 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  */
  72 void 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  */
  79 void 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 */