linux/drivers/video/console/dummycon.c
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   1/*
   2 *  linux/drivers/video/dummycon.c -- A dummy console driver
   3 *
   4 *  To be used if there's no other console driver (e.g. for plain VGA text)
   5 *  available, usually until fbcon takes console over.
   6 */
   7
   8#include <linux/types.h>
   9#include <linux/kdev_t.h>
  10#include <linux/console.h>
  11#include <linux/vt_kern.h>
  12#include <linux/screen_info.h>
  13#include <linux/init.h>
  14#include <linux/module.h>
  15
  16/*
  17 *  Dummy console driver
  18 */
  19
  20#if defined(__arm__)
  21#define DUMMY_COLUMNS   screen_info.orig_video_cols
  22#define DUMMY_ROWS      screen_info.orig_video_lines
  23#elif defined(__hppa__)
  24/* set by Kconfig. Use 80x25 for 640x480 and 160x64 for 1280x1024 */
  25#define DUMMY_COLUMNS   CONFIG_DUMMY_CONSOLE_COLUMNS
  26#define DUMMY_ROWS      CONFIG_DUMMY_CONSOLE_ROWS
  27#else
  28#define DUMMY_COLUMNS   80
  29#define DUMMY_ROWS      25
  30#endif
  31
  32static const char *dummycon_startup(void)
  33{
  34    return "dummy device";
  35}
  36
  37static void dummycon_init(struct vc_data *vc, int init)
  38{
  39    vc->vc_can_do_color = 1;
  40    if (init) {
  41        vc->vc_cols = DUMMY_COLUMNS;
  42        vc->vc_rows = DUMMY_ROWS;
  43    } else
  44        vc_resize(vc, DUMMY_COLUMNS, DUMMY_ROWS);
  45}
  46
  47static int dummycon_dummy(void)
  48{
  49    return 0;
  50}
  51
  52#define DUMMY   (void *)dummycon_dummy
  53
  54/*
  55 *  The console `switch' structure for the dummy console
  56 *
  57 *  Most of the operations are dummies.
  58 */
  59
  60const struct consw dummy_con = {
  61    .owner =            THIS_MODULE,
  62    .con_startup =      dummycon_startup,
  63    .con_init =         dummycon_init,
  64    .con_deinit =       DUMMY,
  65    .con_clear =        DUMMY,
  66    .con_putc =         DUMMY,
  67    .con_putcs =        DUMMY,
  68    .con_cursor =       DUMMY,
  69    .con_scroll =       DUMMY,
  70    .con_bmove =        DUMMY,
  71    .con_switch =       DUMMY,
  72    .con_blank =        DUMMY,
  73    .con_font_set =     DUMMY,
  74    .con_font_get =     DUMMY,
  75    .con_font_default = DUMMY,
  76    .con_font_copy =    DUMMY,
  77    .con_set_palette =  DUMMY,
  78    .con_scrolldelta =  DUMMY,
  79};
  80