drivers/video/console/fbcon.h

   1 /*
   2  *  linux/drivers/video/console/fbcon.h -- Low level frame buffer based console driver
   3  *
   4  *      Copyright (C) 1997 Geert Uytterhoeven
   5  *
   6  *  This file is subject to the terms and conditions of the GNU General Public
   7  *  License.  See the file COPYING in the main directory of this archive
   8  *  for more details.
   9  */
  10
  11 #ifndef _VIDEO_FBCON_H
  12 #define _VIDEO_FBCON_H
  13
  14 #include <linux/config.h>
  15 #include <linux/types.h>
  16 #include <linux/vt_buffer.h>
  17 #include <linux/vt_kern.h>
  18
  19 #include <asm/io.h>
  20
  21    /*
  22     *    This is the interface between the low-level console driver and the
  23     *    low-level frame buffer device
  24     */
  25
  26 struct display {
  27     /* Filled in by the frame buffer device */
  28     u_short inverse;                /* != 0 text black on white as default */
  29     /* Filled in by the low-level console driver */
  30     u_char *fontdata;
  31     int userfont;                   /* != 0 if fontdata kmalloc()ed */
  32     u_short scrollmode;             /* Scroll Method */
  33     short yscroll;                  /* Hardware scrolling */
  34     int vrows;                      /* number of virtual rows */
  35     int cursor_shape;
  36     u32 xres_virtual;
  37     u32 yres_virtual;
  38     u32 height;
  39     u32 width;
  40     u32 bits_per_pixel;
  41     u32 grayscale;
  42     u32 nonstd;
  43     u32 accel_flags;
  44     struct fb_bitfield red;
  45     struct fb_bitfield green;
  46     struct fb_bitfield blue;
  47     struct fb_bitfield transp;
  48     struct fb_videomode *mode;
  49 };
  50
  51     /*
  52      *  Attribute Decoding
  53      */
  54
  55 /* Color */
  56 #define attr_fgcol(fgshift,s)    \
  57         (((s) >> (fgshift)) & 0x0f)
  58 #define attr_bgcol(bgshift,s)    \
  59         (((s) >> (bgshift)) & 0x0f)
  60 #define attr_bgcol_ec(bgshift,vc) \
  61         ((vc) ? (((vc)->vc_video_erase_char >> (bgshift)) & 0x0f) : 0)
  62 #define attr_fgcol_ec(fgshift,vc) \
  63         ((vc) ? (((vc)->vc_video_erase_char >> (fgshift)) & 0x0f) : 0)
  64
  65 /* Monochrome */
  66 #define attr_bold(s) \
  67         ((s) & 0x200)
  68 #define attr_reverse(s) \
  69         ((s) & 0x800)
  70 #define attr_underline(s) \
  71         ((s) & 0x400)
  72 #define attr_blink(s) \
  73         ((s) & 0x8000)
  74
  75     /*
  76      *  Scroll Method
  77      */
  78
  79 /* There are several methods fbcon can use to move text around the screen:
  80  *
  81  *                     Operation   Pan    Wrap
  82  *---------------------------------------------
  83  * SCROLL_MOVE         copyarea    No     No
  84  * SCROLL_PAN_MOVE     copyarea    Yes    No
  85  * SCROLL_WRAP_MOVE    copyarea    No     Yes
  86  * SCROLL_REDRAW       imageblit   No     No
  87  * SCROLL_PAN_REDRAW   imageblit   Yes    No
  88  * SCROLL_WRAP_REDRAW  imageblit   No     Yes
  89  *
  90  * (SCROLL_WRAP_REDRAW is not implemented yet)
  91  *
  92  * In general, fbcon will choose the best scrolling
  93  * method based on the rule below:
  94  *
  95  * Pan/Wrap > accel imageblit > accel copyarea >
  96  * soft imageblit > (soft copyarea)
  97  *
  98  * Exception to the rule: Pan + accel copyarea is
  99  * preferred over Pan + accel imageblit.
 100  *
 101  * The above is typical for PCI/AGP cards. Unless
 102  * overridden, fbcon will never use soft copyarea.
 103  *
 104  * If you need to override the above rule, set the
 105  * appropriate flags in fb_info->flags.  For example,
 106  * to prefer copyarea over imageblit, set
 107  * FBINFO_READS_FAST.
 108  *
 109  * Other notes:
 110  * + use the hardware engine to move the text
 111  *    (hw-accelerated copyarea() and fillrect())
 112  * + use hardware-supported panning on a large virtual screen
 113  * + amifb can not only pan, but also wrap the display by N lines
 114  *    (i.e. visible line i = physical line (i+N) % yres).
 115  * + read what's already rendered on the screen and
 116  *     write it in a different place (this is cfb_copyarea())
 117  * + re-render the text to the screen
 118  *
 119  * Whether to use wrapping or panning can only be figured out at
 120  * runtime (when we know whether our font height is a multiple
 121  * of the pan/wrap step)
 122  *
 123  */
 124
 125 #define SCROLL_MOVE        0x001
 126 #define SCROLL_PAN_MOVE    0x002
 127 #define SCROLL_WRAP_MOVE   0x003
 128 #define SCROLL_REDRAW      0x004
 129 #define SCROLL_PAN_REDRAW  0x005
 130
 131 extern int fb_console_init(void);
 132
 133 #endif /* _VIDEO_FBCON_H */