edge/system/qcomgpsd/modemdiag.py

95 lines
3.3 KiB
Python

import select
from serial import Serial
from crcmod import mkCrcFun
from struct import pack, unpack_from, calcsize
class ModemDiag:
def __init__(self):
self.serial = self.open_serial()
self.pend = b''
def open_serial(self):
serial = Serial("/dev/ttyUSB0", baudrate=115200, rtscts=True, dsrdtr=True, timeout=0, exclusive=True)
serial.flush()
serial.reset_input_buffer()
serial.reset_output_buffer()
return serial
ccitt_crc16 = mkCrcFun(0x11021, initCrc=0, xorOut=0xffff)
ESCAPE_CHAR = b'\x7d'
TRAILER_CHAR = b'\x7e'
def hdlc_encapsulate(self, payload):
payload += pack('<H', ModemDiag.ccitt_crc16(payload))
payload = payload.replace(self.ESCAPE_CHAR, bytes([self.ESCAPE_CHAR[0], self.ESCAPE_CHAR[0] ^ 0x20]))
payload = payload.replace(self.TRAILER_CHAR, bytes([self.ESCAPE_CHAR[0], self.TRAILER_CHAR[0] ^ 0x20]))
payload += self.TRAILER_CHAR
return payload
def hdlc_decapsulate(self, payload):
assert len(payload) >= 3
assert payload[-1:] == self.TRAILER_CHAR
payload = payload[:-1]
payload = payload.replace(bytes([self.ESCAPE_CHAR[0], self.TRAILER_CHAR[0] ^ 0x20]), self.TRAILER_CHAR)
payload = payload.replace(bytes([self.ESCAPE_CHAR[0], self.ESCAPE_CHAR[0] ^ 0x20]), self.ESCAPE_CHAR)
assert payload[-2:] == pack('<H', ModemDiag.ccitt_crc16(payload[:-2]))
return payload[:-2]
def recv(self):
# self.serial.read_until makes tons of syscalls!
raw_payload = [self.pend]
while self.TRAILER_CHAR not in raw_payload[-1]:
select.select([self.serial.fd], [], [])
raw = self.serial.read(0x10000)
raw_payload.append(raw)
raw_payload = b''.join(raw_payload)
raw_payload, self.pend = raw_payload.split(self.TRAILER_CHAR, 1)
raw_payload += self.TRAILER_CHAR
unframed_message = self.hdlc_decapsulate(raw_payload)
return unframed_message[0], unframed_message[1:]
def send(self, packet_type, packet_payload):
self.serial.write(self.hdlc_encapsulate(bytes([packet_type]) + packet_payload))
# *** end class ***
DIAG_LOG_F = 16
DIAG_LOG_CONFIG_F = 115
LOG_CONFIG_RETRIEVE_ID_RANGES_OP = 1
LOG_CONFIG_SET_MASK_OP = 3
LOG_CONFIG_SUCCESS_S = 0
def send_recv(diag, packet_type, packet_payload):
diag.send(packet_type, packet_payload)
while 1:
opcode, payload = diag.recv()
if opcode != DIAG_LOG_F:
break
return opcode, payload
def setup_logs(diag, types_to_log):
opcode, payload = send_recv(diag, DIAG_LOG_CONFIG_F, pack('<3xI', LOG_CONFIG_RETRIEVE_ID_RANGES_OP))
header_spec = '<3xII'
operation, status = unpack_from(header_spec, payload)
assert operation == LOG_CONFIG_RETRIEVE_ID_RANGES_OP
assert status == LOG_CONFIG_SUCCESS_S
log_masks = unpack_from('<16I', payload, calcsize(header_spec))
for log_type, log_mask_bitsize in enumerate(log_masks):
if log_mask_bitsize:
log_mask = [0] * ((log_mask_bitsize+7)//8)
for i in range(log_mask_bitsize):
if ((log_type<<12)|i) in types_to_log:
log_mask[i//8] |= 1 << (i%8)
opcode, payload = send_recv(diag, DIAG_LOG_CONFIG_F, pack('<3xIII',
LOG_CONFIG_SET_MASK_OP,
log_type,
log_mask_bitsize
) + bytes(log_mask))
assert opcode == DIAG_LOG_CONFIG_F
operation, status = unpack_from(header_spec, payload)
assert operation == LOG_CONFIG_SET_MASK_OP
assert status == LOG_CONFIG_SUCCESS_S