drivers/video/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/tty.h>
  11 #include <linux/console.h>
  12 #include <linux/console_struct.h>
  13 #include <linux/vt_kern.h>
  14 #include <linux/init.h>
  15
  16 /*
  17  *  Dummy console driver
  18  */
  19
  20 #if defined(__arm__)
  21 #define DUMMY_COLUMNS   ORIG_VIDEO_COLS
  22 #define DUMMY_ROWS      ORIG_VIDEO_LINES
  23 #else
  24 #define DUMMY_COLUMNS   80
  25 #define DUMMY_ROWS      25
  26 #endif
  27
  28 static const char *dummycon_startup(void)
  29 {
  30     return "dummy device";
  31 }
  32
  33 static void dummycon_init(struct vc_data *conp, int init)
  34 {
  35     conp->vc_can_do_color = 1;
  36     if (init) {
  37         conp->vc_cols = DUMMY_COLUMNS;
  38         conp->vc_rows = DUMMY_ROWS;
  39     } else
  40         vc_resize_con(DUMMY_ROWS, DUMMY_COLUMNS, conp->vc_num);
  41 }
  42
  43 static int dummycon_dummy(void)
  44 {
  45     return 0;
  46 }
  47
  48 /*
  49  *  The console `switch' structure for the dummy console
  50  *
  51  *  Most of the operations are dummies.
  52  */
  53
  54 struct consw dummy_con = {
  55     dummycon_startup, dummycon_init,
  56     (void *)dummycon_dummy,     /* con_deinit */
  57     (void *)dummycon_dummy,     /* con_clear */
  58     (void *)dummycon_dummy,     /* con_putc */
  59     (void *)dummycon_dummy,     /* con_putcs */
  60     (void *)dummycon_dummy,     /* con_cursor */
  61     (void *)dummycon_dummy,     /* con_scroll */
  62     (void *)dummycon_dummy,     /* con_bmove */
  63     (void *)dummycon_dummy,     /* con_switch */
  64     (void *)dummycon_dummy,     /* con_blank */
  65     (void *)dummycon_dummy,     /* con_font_op */
  66     (void *)dummycon_dummy,     /* con_set_palette */
  67     (void *)dummycon_dummy,     /* con_scrolldelta */
  68     NULL,                       /* con_set_origin */
  69     NULL,                       /* con_save_screen */
  70 };