xref: /linux/kernel/power/console.c (revision 8d233558)
1 /*
2  * drivers/power/process.c - Functions for saving/restoring console.
3  *
4  * Originally from swsusp.
5  */
6 
7 #include <linux/vt_kern.h>
8 #include <linux/kbd_kern.h>
9 #include <linux/console.h>
10 #include <linux/module.h>
11 #include "power.h"
12 
13 #if defined(CONFIG_VT) && defined(CONFIG_VT_CONSOLE)
14 #define SUSPEND_CONSOLE	(MAX_NR_CONSOLES-1)
15 
16 static int orig_fgconsole, orig_kmsg;
17 
18 int pm_prepare_console(void)
19 {
20 	orig_fgconsole = vt_move_to_console(SUSPEND_CONSOLE, 1);
21 	if (orig_fgconsole < 0)
22 		return 1;
23 
24 	orig_kmsg = kmsg_redirect;
25 	kmsg_redirect = SUSPEND_CONSOLE;
26 	return 0;
27 }
28 
29 void pm_restore_console(void)
30 {
31 	if (orig_fgconsole >= 0) {
32 		vt_move_to_console(orig_fgconsole, 0);
33 		kmsg_redirect = orig_kmsg;
34 	}
35 }
36 #endif
37