drivers/video/console/dummycon.c

   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
  32 static const char *dummycon_startup(void)
  33 {
  34     return "dummy device";
  35 }
  36
  37 static 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
  47 static 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
  60 const 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 EXPORT_SYMBOL_GPL(dummy_con);