160 lines
		
	
	
		
			3.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			160 lines
		
	
	
		
			3.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
 | |
|  *  linux/drivers/video/dummycon.c -- A dummy console driver
 | |
|  *
 | |
|  *  To be used if there's no other console driver (e.g. for plain VGA text)
 | |
|  *  available, usually until fbcon takes console over.
 | |
|  */
 | |
| 
 | |
| #include <linux/types.h>
 | |
| #include <linux/kdev_t.h>
 | |
| #include <linux/console.h>
 | |
| #include <linux/vt_kern.h>
 | |
| #include <linux/screen_info.h>
 | |
| #include <linux/init.h>
 | |
| #include <linux/module.h>
 | |
| 
 | |
| /*
 | |
|  *  Dummy console driver
 | |
|  */
 | |
| 
 | |
| #if defined(__arm__)
 | |
| #define DUMMY_COLUMNS	screen_info.orig_video_cols
 | |
| #define DUMMY_ROWS	screen_info.orig_video_lines
 | |
| #else
 | |
| /* set by Kconfig. Use 80x25 for 640x480 and 160x64 for 1280x1024 */
 | |
| #define DUMMY_COLUMNS	CONFIG_DUMMY_CONSOLE_COLUMNS
 | |
| #define DUMMY_ROWS	CONFIG_DUMMY_CONSOLE_ROWS
 | |
| #endif
 | |
| 
 | |
| #ifdef CONFIG_FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER
 | |
| /* These are both protected by the console_lock */
 | |
| static RAW_NOTIFIER_HEAD(dummycon_output_nh);
 | |
| static bool dummycon_putc_called;
 | |
| 
 | |
| void dummycon_register_output_notifier(struct notifier_block *nb)
 | |
| {
 | |
| 	raw_notifier_chain_register(&dummycon_output_nh, nb);
 | |
| 
 | |
| 	if (dummycon_putc_called)
 | |
| 		nb->notifier_call(nb, 0, NULL);
 | |
| }
 | |
| 
 | |
| void dummycon_unregister_output_notifier(struct notifier_block *nb)
 | |
| {
 | |
| 	raw_notifier_chain_unregister(&dummycon_output_nh, nb);
 | |
| }
 | |
| 
 | |
| static void dummycon_putc(struct vc_data *vc, int c, int ypos, int xpos)
 | |
| {
 | |
| 	dummycon_putc_called = true;
 | |
| 	raw_notifier_call_chain(&dummycon_output_nh, 0, NULL);
 | |
| }
 | |
| 
 | |
| static void dummycon_putcs(struct vc_data *vc, const unsigned short *s,
 | |
| 			   int count, int ypos, int xpos)
 | |
| {
 | |
| 	int i;
 | |
| 
 | |
| 	if (!dummycon_putc_called) {
 | |
| 		/* Ignore erases */
 | |
| 		for (i = 0 ; i < count; i++) {
 | |
| 			if (s[i] != vc->vc_video_erase_char)
 | |
| 				break;
 | |
| 		}
 | |
| 		if (i == count)
 | |
| 			return;
 | |
| 
 | |
| 		dummycon_putc_called = true;
 | |
| 	}
 | |
| 
 | |
| 	raw_notifier_call_chain(&dummycon_output_nh, 0, NULL);
 | |
| }
 | |
| 
 | |
| static int dummycon_blank(struct vc_data *vc, int blank, int mode_switch)
 | |
| {
 | |
| 	/* Redraw, so that we get putc(s) for output done while blanked */
 | |
| 	return 1;
 | |
| }
 | |
| #else
 | |
| static void dummycon_putc(struct vc_data *vc, int c, int ypos, int xpos) { }
 | |
| static void dummycon_putcs(struct vc_data *vc, const unsigned short *s,
 | |
| 			   int count, int ypos, int xpos) { }
 | |
| static int dummycon_blank(struct vc_data *vc, int blank, int mode_switch)
 | |
| {
 | |
| 	return 0;
 | |
| }
 | |
| #endif
 | |
| 
 | |
| static const char *dummycon_startup(void)
 | |
| {
 | |
|     return "dummy device";
 | |
| }
 | |
| 
 | |
| static void dummycon_init(struct vc_data *vc, int init)
 | |
| {
 | |
|     vc->vc_can_do_color = 1;
 | |
|     if (init) {
 | |
| 	vc->vc_cols = DUMMY_COLUMNS;
 | |
| 	vc->vc_rows = DUMMY_ROWS;
 | |
|     } else
 | |
| 	vc_resize(vc, DUMMY_COLUMNS, DUMMY_ROWS);
 | |
| }
 | |
| 
 | |
| static void dummycon_deinit(struct vc_data *vc) { }
 | |
| static void dummycon_clear(struct vc_data *vc, int sy, int sx, int height,
 | |
| 			   int width) { }
 | |
| static void dummycon_cursor(struct vc_data *vc, int mode) { }
 | |
| 
 | |
| static bool dummycon_scroll(struct vc_data *vc, unsigned int top,
 | |
| 			    unsigned int bottom, enum con_scroll dir,
 | |
| 			    unsigned int lines)
 | |
| {
 | |
| 	return false;
 | |
| }
 | |
| 
 | |
| static int dummycon_switch(struct vc_data *vc)
 | |
| {
 | |
| 	return 0;
 | |
| }
 | |
| 
 | |
| static int dummycon_font_set(struct vc_data *vc, struct console_font *font,
 | |
| 			     unsigned int flags)
 | |
| {
 | |
| 	return 0;
 | |
| }
 | |
| 
 | |
| static int dummycon_font_default(struct vc_data *vc,
 | |
| 				 struct console_font *font, char *name)
 | |
| {
 | |
| 	return 0;
 | |
| }
 | |
| 
 | |
| static int dummycon_font_copy(struct vc_data *vc, int con)
 | |
| {
 | |
| 	return 0;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  *  The console `switch' structure for the dummy console
 | |
|  *
 | |
|  *  Most of the operations are dummies.
 | |
|  */
 | |
| 
 | |
| const struct consw dummy_con = {
 | |
| 	.owner =		THIS_MODULE,
 | |
| 	.con_startup =	dummycon_startup,
 | |
| 	.con_init =		dummycon_init,
 | |
| 	.con_deinit =	dummycon_deinit,
 | |
| 	.con_clear =	dummycon_clear,
 | |
| 	.con_putc =		dummycon_putc,
 | |
| 	.con_putcs =	dummycon_putcs,
 | |
| 	.con_cursor =	dummycon_cursor,
 | |
| 	.con_scroll =	dummycon_scroll,
 | |
| 	.con_switch =	dummycon_switch,
 | |
| 	.con_blank =	dummycon_blank,
 | |
| 	.con_font_set =	dummycon_font_set,
 | |
| 	.con_font_default =	dummycon_font_default,
 | |
| 	.con_font_copy =	dummycon_font_copy,
 | |
| };
 | |
| EXPORT_SYMBOL_GPL(dummy_con);
 | 
