blob: a3961b205de743c30f9588e02d28f1f959b46db6 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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>
Andres Salomonb6f448e2008-04-28 02:15:03 -070010#include <linux/module.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070011#include "power.h"
12
Rafael J. Wysocki46cd2f32006-02-07 12:58:50 -080013#if defined(CONFIG_VT) && defined(CONFIG_VT_CONSOLE)
14#define SUSPEND_CONSOLE (MAX_NR_CONSOLES-1)
15
Linus Torvalds1da177e2005-04-16 15:20:36 -070016static int orig_fgconsole, orig_kmsg;
Andres Salomonb6f448e2008-04-28 02:15:03 -070017static int disable_vt_switch;
18
19/*
20 * Normally during a suspend, we allocate a new console and switch to it.
21 * When we resume, we switch back to the original console. This switch
22 * can be slow, so on systems where the framebuffer can handle restoration
23 * of video registers anyways, there's little point in doing the console
24 * switch. This function allows you to disable it by passing it '0'.
25 */
26void pm_set_vt_switch(int do_switch)
27{
28 acquire_console_sem();
29 disable_vt_switch = !do_switch;
30 release_console_sem();
31}
32EXPORT_SYMBOL(pm_set_vt_switch);
Linus Torvalds1da177e2005-04-16 15:20:36 -070033
34int pm_prepare_console(void)
35{
Linus Torvalds1da177e2005-04-16 15:20:36 -070036 acquire_console_sem();
37
Andres Salomonb6f448e2008-04-28 02:15:03 -070038 if (disable_vt_switch) {
39 release_console_sem();
40 return 0;
41 }
42
Linus Torvalds1da177e2005-04-16 15:20:36 -070043 orig_fgconsole = fg_console;
44
45 if (vc_allocate(SUSPEND_CONSOLE)) {
46 /* we can't have a free VC for now. Too bad,
47 * we don't want to mess the screen for now. */
48 release_console_sem();
49 return 1;
50 }
51
Andrew Johnsonb257bc02007-03-16 13:38:24 -080052 if (set_console(SUSPEND_CONSOLE)) {
53 /*
54 * We're unable to switch to the SUSPEND_CONSOLE.
55 * Let the calling function know so it can decide
56 * what to do.
57 */
58 release_console_sem();
59 return 1;
60 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070061 release_console_sem();
62
63 if (vt_waitactive(SUSPEND_CONSOLE)) {
64 pr_debug("Suspend: Can't switch VCs.");
65 return 1;
66 }
67 orig_kmsg = kmsg_redirect;
68 kmsg_redirect = SUSPEND_CONSOLE;
Linus Torvalds1da177e2005-04-16 15:20:36 -070069 return 0;
70}
71
72void pm_restore_console(void)
73{
Linus Torvalds1da177e2005-04-16 15:20:36 -070074 acquire_console_sem();
Andres Salomonb6f448e2008-04-28 02:15:03 -070075 if (disable_vt_switch) {
76 release_console_sem();
77 return;
78 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070079 set_console(orig_fgconsole);
80 release_console_sem();
Arve Hjønnevågb090f9f2009-02-14 02:06:17 +010081
82 if (vt_waitactive(orig_fgconsole)) {
83 pr_debug("Resume: Can't switch VCs.");
84 return;
85 }
86
Linus Torvalds1da177e2005-04-16 15:20:36 -070087 kmsg_redirect = orig_kmsg;
Linus Torvalds1da177e2005-04-16 15:20:36 -070088}
Rafael J. Wysockif7b89882006-02-01 03:05:21 -080089#endif