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/*
* watchdog
*
* Copyright 2014-present Facebook. All Rights Reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* Utility library to handle the aspeed watchdog. Only one watchdog
* should be in use at any time throughout the entire system (multiple users
* will not cause adverse effects but the behavior of the watchdog becomes
* undefined).
*
* The watchdog can be started in either manual or automatic mode. In manual
* mode, the watchdog has to be constantly reset by the user via the
* kick_watchdog() function. Under automatic mode, the watchdog will
* run in a separate thread and reset the timer on its own so no intervention
* is required from the user.
*
* In both modes, the watchdog timer will not stop when the process is
* terminated, unless a call to stop_watchdog() has been made beforehand, or
* if the user runs in manual mode and uses a non persistent watchdog kick.
*
* The default timeout for the watchdog is 11 seconds. When this time period
* elapses, the ARM chip is restarted and the kernel is rebooted. Other
* hardware state is not reset, so this may introduce strange behavior on
* reboot (example: an I2C bus may be left in the open state, triggering
* constant interrupts). In rare cases, this could result in the kernel
* failing to fully restart itself and thus preclude the possibility of
* reinitializing the watchdog timer. Someone will then have to go over and
* physically restart the machine.
*
* The alternative to the soft reset is to request the watchdog device driver
* for a hard reset on timeout. However this will stop the fans. If the
* kernel fails to fully boot and restart the fan daemon, the system could
* overheat. For this reason, we've chosen to take the risk of a stuck soft
* reset instead.
*
*/
/* Forward declarations. */
int start_watchdog(const int auto_mode);
enum watchdog_persistent_en {
WATCHDOG_SET_PERSISTENT,
WATCHDOG_SET_NONPERSISTENT,
};
void set_persistent_watchdog(enum watchdog_persistent_en persistent);
int kick_watchdog();
void stop_watchdog();
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