+static void acpi_sleep_tts_switch(u32 acpi_state)
+{
+ union acpi_object in_arg = { ACPI_TYPE_INTEGER };
+ struct acpi_object_list arg_list = { 1, &in_arg };
+ acpi_status status = AE_OK;
+
+ in_arg.integer.value = acpi_state;
+ status = acpi_evaluate_object(NULL, "\\_TTS", &arg_list, NULL);
+ if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
+ /*
+ * OS can't evaluate the _TTS object correctly. Some warning
+ * message will be printed. But it won't break anything.
+ */
+ printk(KERN_NOTICE "Failure in evaluating _TTS object\n");
+ }
+}
+
+static int tts_notify_reboot(struct notifier_block *this,
+ unsigned long code, void *x)
+{
+ acpi_sleep_tts_switch(ACPI_STATE_S5);
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block tts_notifier = {
+ .notifier_call = tts_notify_reboot,
+ .next = NULL,
+ .priority = 0,
+};
+