panda/python/canhandle.py

54 lines
1.4 KiB
Python

import struct
import signal
from .base import BaseHandle
class CanHandle(BaseHandle):
def __init__(self, p, bus):
self.p = p
self.bus = bus
def transact(self, dat):
def _handle_timeout(signum, frame):
# will happen on reset or can error
raise TimeoutError
signal.signal(signal.SIGALRM, _handle_timeout)
signal.alarm(1)
try:
self.p.isotp_send(1, dat, self.bus, recvaddr=2)
finally:
signal.alarm(0)
signal.signal(signal.SIGALRM, _handle_timeout)
signal.alarm(1)
try:
ret = self.p.isotp_recv(2, self.bus, sendaddr=1)
finally:
signal.alarm(0)
return ret
def close(self):
pass
def controlWrite(self, request_type, request, value, index, data, timeout=0, expect_disconnect=False):
# ignore data in reply, panda doesn't use it
return self.controlRead(request_type, request, value, index, 0, timeout)
def controlRead(self, request_type, request, value, index, length, timeout=0):
dat = struct.pack("HHBBHHH", 0, 0, request_type, request, value, index, length)
return self.transact(dat)
def bulkWrite(self, endpoint, data, timeout=0):
if len(data) > 0x10:
raise ValueError("Data must not be longer than 0x10")
dat = struct.pack("HH", endpoint, len(data)) + data
return self.transact(dat)
def bulkRead(self, endpoint, length, timeout=0):
dat = struct.pack("HH", endpoint, 0)
return self.transact(dat)