kernel/power/console.c

   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 "power.h"
  11
  12 #ifdef SUSPEND_CONSOLE
  13 static int orig_fgconsole, orig_kmsg;
  14
  15 int pm_prepare_console(void)
  16 {
  17         acquire_console_sem();
  18
  19         orig_fgconsole = fg_console;
  20
  21         if (vc_allocate(SUSPEND_CONSOLE)) {
  22           /* we can't have a free VC for now. Too bad,
  23            * we don't want to mess the screen for now. */
  24                 release_console_sem();
  25                 return 1;
  26         }
  27
  28         set_console(SUSPEND_CONSOLE);
  29         release_console_sem();
  30
  31         if (vt_waitactive(SUSPEND_CONSOLE)) {
  32                 pr_debug("Suspend: Can't switch VCs.");
  33                 return 1;
  34         }
  35         orig_kmsg = kmsg_redirect;
  36         kmsg_redirect = SUSPEND_CONSOLE;
  37         return 0;
  38 }
  39
  40 void pm_restore_console(void)
  41 {
  42         acquire_console_sem();
  43         set_console(orig_fgconsole);
  44         release_console_sem();
  45         kmsg_redirect = orig_kmsg;
  46         return;
  47 }
  48 #endif