osmo-lpmgd/osmocom/lpmgd/switcher_sispm.py

128 lines
4.8 KiB
Python

# Import from osmo-gsm-tester.git/src/osmo_gsm_tester/obj/powersupply_sispm.py
# osmo-lpmgd: class defining a sispm Power Supply object
#
# Copyright (C) 2018,2023 by sysmocom - s.f.m.c. GmbH
#
# Author: Pau Espin Pedrol <pespin@sysmocom.de>
# Author: Harald Welte <laforge@osmocom.org>
#
# 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 3 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, see <http://www.gnu.org/licenses/>.
import logging
import pysispm
from osmocom.lpmgd.model import Switcher, SwitcherGroup
logger = logging.getLogger(__name__)
class SispmSwitcher(Switcher):
"""Switcher implementation using pysispm.
The device object from sismpm is not cached into an attribute of the class
instance because it is actually a libusb object keeping the device assigned
to it until it destroyed, meaning it will block other users to use the whole
device until the object is released. Instead, we pick the object in the
smallest scope possible, and we re-try if we receive a "Resource Busy" error
because we know it will be available in short time.
"""
def _retry_usberr(self, func, *args):
"""Run function until it runs successfully, retry on spurious errors.
Sometimes when operating the usb device, libusb reports the following spurious exception:
[Errno 16] Resource busy -> This can appear if another instance is using the device.
[Errno 110] Operation timed out
Retrying after that it's usually enough.
"""
while True:
try:
ret = func(*args)
return ret
except USBError as e:
if e.errno == 16 or e.errno==110:
self.log.debug('skipping USB error, retrying', repr(e))
#MainLoop.sleep(0.1)
# FIXME: synchronous sleep here?
continue
raise e
def _get_device(self):
"""Get the sispm device object.
It should be kept alive as short as possible as it blocks other users
from using the device until the object is released.
"""
mydevid = self.conf.get('device')
devices = self._retry_usberr(sispm.connect)
for d in devices:
did = self._retry_usberr(sispm.getid, d)
self.dbg('detected device:', did)
if did == mydevid:
self.dbg('found matching device: %s' % did)
return d
return None
########################
# PUBLIC - INTERNAL API
########################
#def __init__(self, group: SwitcherGroup, name: str, conf):
def __init__(self, conf):
super().__init__(conf, 'sispm')
self.log = logger
import sispm
from usb.core import USBError
mydevid = conf.get('device')
if mydevid is None:
raise self.log.Error('No "device" attribute provided in supply conf!')
self.set_name('sispm-'+mydevid)
myport = conf.get('port')
if myport is None:
raise self.log.Error('No "port" attribute provided in power_supply conf!')
if not int(myport):
raise self.log.Error('Wrong non numeric "port" attribute provided in power_supply conf!')
self.set_name('sispm-'+mydevid+'-'+myport)
self.port = int(myport)
device = self._get_device()
if device is None:
raise self.log.Error('device with with id %s not found!' % mydevid)
dmin = self._retry_usberr(sispm.getminport, device)
dmax = self._retry_usberr(sispm.getmaxport, device)
if dmin > self.port or dmax < self.port:
raise self.log.Error('Out of range "port" attribute provided in power_supply conf!')
def _obtain_actual_status(self):
"""Get whether the device is powered on or off."""
if self._retry_usberr(sispm.getstatus, self._get_device(), self.port):
return 'on'
else:
return 'off'
def _status_change(self, new_status: str):
"""Turn on or off the device."""
if new_status == 'on':
self.dbg('switchon')
self._retry_usberr(sispm.switchon, self._get_device(), self.port)
else:
self.dbg('switchoff')
self._retry_usberr(sispm.switchoff, self._get_device(), self.port)
# vim: expandtab tabstop=4 shiftwidth=4