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