pebble/tools/serial_port_wrapper.py
2025-01-27 11:38:16 -08:00

160 lines
4.7 KiB
Python

# Copyright 2024 Google LLC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import serial
import threading
import time
PEBBLE_BAUD_RATE = 230400
SERIAL_READ_TIMEOUT = 0.1
SERIAL_WRAPPER_READ_TIMEOUT = 0.5
class SerialPortWrapperException(Exception):
pass
class SerialPortWrapper(threading.Thread):
def __init__(self, tty, logfile='serial_dump.txt', baud_rate=PEBBLE_BAUD_RATE):
threading.Thread.__init__(self)
self.tty = tty
if tty.startswith('ftdi://'):
import pyftdi.serialext
self.s = serial.serial_for_url(tty, baud_rate, timeout=SERIAL_READ_TIMEOUT)
self.read_size = 1
self.debug_out = None
# if a logfile is specified log serial output. If a file descriptor
# is provided log to the descriptor but do not close the descriptor.
if logfile is not None:
if isinstance(logfile, basestring):
self.debug_out = open(logfile, 'wb')
self._close_debug = True
elif isinstance(logfile, file):
self.debug_out = logfile
self._close_debug = False
else:
raise ValueError('logfile must be a filename or an open file '
'descriptor.')
# This signal is used to protect and signal changes in the below
# self.data member variable
self.signal = threading.Condition()
self.data = ''
self.die = False
self.daemon = True
self.start()
def run(self):
while not self.die:
data = self.s.read(self.read_size)
if len(data):
#print 'received data <(%s)>' % data
self.signal.acquire()
try:
self.data += data
if self.debug_out is not None:
self.debug_out.write(data)
self.debug_out.flush()
self.signal.notify_all()
finally:
self.signal.release()
def write_fast(self, data):
#print 'writing <(%s)>' % strip_unprintable_chars(data)
rv = self.s.write(data)
return rv
def write_slow(self, data):
for c in data:
self.s.write(c)
time.sleep(0.01)
def write(self, data):
self.write_slow(data)
def readline(self, timeout=SERIAL_WRAPPER_READ_TIMEOUT):
result = ''
self.signal.acquire()
try:
# Try to find a newline character. If we don't have one, wait until we
# receive more data before checking again. If we hit the timeout without
# receiving anything just return what we have.
idx = self.data.find('\n')
while idx == -1:
prev_data_len = len(self.data)
self.signal.wait(timeout)
if (prev_data_len != len(self.data)):
idx = self.data.find('\n')
else:
idx = len(self.data) - 1
if len(self.data) == 0:
break
idx += 1
result = self.data[:idx].strip()
self.data = self.data[idx:]
#print 'returning <(%s)>, %u remaining' % (result, len(self.data))
finally:
self.signal.release()
return result
def read(self, timeout=SERIAL_WRAPPER_READ_TIMEOUT):
self.signal.acquire()
while True:
prev_data_len = len(self.data)
self.signal.wait(timeout)
if (prev_data_len == len(self.data)):
# No new data available after our timeout, assume we're done
break
result = self.data
self.data = ''
self.signal.release()
return result
def read_regex(self, regex, timeout=SERIAL_WRAPPER_READ_TIMEOUT):
match = None
while not match:
match = regex.search(self.readline(timeout))
return match
def clear(self):
self.signal.acquire()
self.data = ''
self.signal.release()
def close(self):
self.die = True
self.join()
self.s.close()
if self.debug_out is not None and self._close_debug:
self.debug_out.close()