sonic-buildimage/device/celestica/x86_64-cel_e1031-r0/sonic_platform/watchdog.py
Joe LeVeque bd14dd377c [Celestica] Ensure concrete platform API classes call base class initializer (#6852)
In preparation for the merging of Azure/sonic-platform-common#173, which properly defines class and instance members in the Platform API base classes.

It is proper object-oriented methodology to call the base class initializer, even if it is only the default initializer. This also future-proofs the potential addition of custom initializers in the base classes down the road.
2021-03-04 21:23:05 +00:00

233 lines
6.5 KiB
Python

#############################################################################
# Celestica
#
# Watchdog contains an implementation of SONiC Platform Base API
#
#############################################################################
import ctypes
import fcntl
import os
import subprocess
import time
import array
try:
from sonic_platform_base.watchdog_base import WatchdogBase
except ImportError as e:
raise ImportError(str(e) + "- required module not found")
""" ioctl constants """
IO_WRITE = 0x40000000
IO_READ = 0x80000000
IO_READ_WRITE = 0xC0000000
IO_SIZE_INT = 0x00040000
IO_SIZE_40 = 0x00280000
IO_TYPE_WATCHDOG = ord('W') << 8
WDR_INT = IO_READ | IO_SIZE_INT | IO_TYPE_WATCHDOG
WDR_40 = IO_READ | IO_SIZE_40 | IO_TYPE_WATCHDOG
WDWR_INT = IO_READ_WRITE | IO_SIZE_INT | IO_TYPE_WATCHDOG
""" Watchdog ioctl commands """
WDIOC_GETSUPPORT = 0 | WDR_40
WDIOC_GETSTATUS = 1 | WDR_INT
WDIOC_GETBOOTSTATUS = 2 | WDR_INT
WDIOC_GETTEMP = 3 | WDR_INT
WDIOC_SETOPTIONS = 4 | WDR_INT
WDIOC_KEEPALIVE = 5 | WDR_INT
WDIOC_SETTIMEOUT = 6 | WDWR_INT
WDIOC_GETTIMEOUT = 7 | WDR_INT
WDIOC_SETPRETIMEOUT = 8 | WDWR_INT
WDIOC_GETPRETIMEOUT = 9 | WDR_INT
WDIOC_GETTIMELEFT = 10 | WDR_INT
""" Watchdog status constants """
WDIOS_DISABLECARD = 0x0001
WDIOS_ENABLECARD = 0x0002
WDT_COMMON_ERROR = -1
WD_MAIN_IDENTITY = "iTCO_wdt"
WDT_SYSFS_PATH = "/sys/class/watchdog/"
class Watchdog(WatchdogBase):
def __init__(self):
WatchdogBase.__init__(self)
self.watchdog, self.wdt_main_dev_name = self._get_wdt()
self.status_path = "/sys/class/watchdog/%s/status" % self.wdt_main_dev_name
self.state_path = "/sys/class/watchdog/%s/state" % self.wdt_main_dev_name
self.timeout_path = "/sys/class/watchdog/%s/timeout" % self.wdt_main_dev_name
# Set default value
self._disable()
self.armed = False
self.timeout = self._gettimeout(self.timeout_path)
def _is_wd_main(self, dev):
"""
Checks watchdog identity
"""
identity = self._read_file(
"{}/{}/identity".format(WDT_SYSFS_PATH, dev))
return identity == WD_MAIN_IDENTITY
def _get_wdt(self):
"""
Retrieves watchdog device
"""
wdt_main_dev_list = [dev for dev in os.listdir(
"/dev/") if dev.startswith("watchdog") and self._is_wd_main(dev)]
if not wdt_main_dev_list:
return None
wdt_main_dev_name = wdt_main_dev_list[0]
watchdog_device_path = "/dev/{}".format(wdt_main_dev_name)
watchdog = os.open(watchdog_device_path, os.O_RDWR)
return watchdog, wdt_main_dev_name
def _read_file(self, file_path):
"""
Read text file
"""
try:
with open(file_path, "r") as fd:
txt = fd.read()
except IOError:
return WDT_COMMON_ERROR
return txt.strip()
def _enable(self):
"""
Turn on the watchdog timer
"""
req = array.array('h', [WDIOS_ENABLECARD])
fcntl.ioctl(self.watchdog, WDIOC_SETOPTIONS, req, False)
def _disable(self):
"""
Turn off the watchdog timer
"""
req = array.array('h', [WDIOS_DISABLECARD])
fcntl.ioctl(self.watchdog, WDIOC_SETOPTIONS, req, False)
def _keepalive(self):
"""
Keep alive watchdog timer
"""
fcntl.ioctl(self.watchdog, WDIOC_KEEPALIVE)
def _settimeout(self, seconds):
"""
Set watchdog timer timeout
@param seconds - timeout in seconds
@return is the actual set timeout
"""
req = array.array('I', [seconds])
fcntl.ioctl(self.watchdog, WDIOC_SETTIMEOUT, req, True)
return int(req[0])
def _gettimeout(self, timeout_path):
"""
Get watchdog timeout
@return watchdog timeout
"""
req = array.array('I', [0])
fcntl.ioctl(self.watchdog, WDIOC_GETTIMEOUT, req, True)
return int(req[0])
def _gettimeleft(self):
"""
Get time left before watchdog timer expires
@return time left in seconds
"""
req = array.array('I', [0])
fcntl.ioctl(self.watchdog, WDIOC_GETTIMELEFT, req, True)
return int(req[0])
#################################################################
def arm(self, seconds):
"""
Arm the hardware watchdog with a timeout of <seconds> seconds.
If the watchdog is currently armed, calling this function will
simply reset the timer to the provided value. If the underlying
hardware does not support the value provided in <seconds>, this
method should arm the watchdog with the *next greater* available
value.
Returns:
An integer specifying the *actual* number of seconds the watchdog
was armed with. On failure returns -1.
"""
ret = WDT_COMMON_ERROR
if seconds < 0:
return ret
try:
if self.timeout != seconds:
self.timeout = self._settimeout(seconds)
if self.armed:
self._keepalive()
else:
self._enable()
self.armed = True
ret = self.timeout
except IOError as e:
pass
return ret
def disarm(self):
"""
Disarm the hardware watchdog
Returns:
A boolean, True if watchdog is disarmed successfully, False if not
"""
disarmed = False
if self.is_armed():
try:
self._disable()
self.armed = False
disarmed = True
except IOError:
pass
return disarmed
def is_armed(self):
"""
Retrieves the armed state of the hardware watchdog.
Returns:
A boolean, True if watchdog is armed, False if not
"""
return self.armed
def get_remaining_time(self):
"""
If the watchdog is armed, retrieve the number of seconds remaining on
the watchdog timer
Returns:
An integer specifying the number of seconds remaining on thei
watchdog timer. If the watchdog is not armed, returns -1.
"""
timeleft = WDT_COMMON_ERROR
if self.armed:
try:
timeleft = self._gettimeleft()
except IOError:
pass
return timeleft
def __del__(self):
"""
Close watchdog
"""
os.close(self.watchdog)