klipper-dgus/klippy/serialhdl.py

# Serial port management for firmware communication
#
# Copyright (C) 2016,2017  Kevin O'Connor <kevin@koconnor.net>
#
# This file may be distributed under the terms of the GNU GPLv3 license.
import logging, threading
import serial

import msgproto, chelper, util

class error(Exception):
    pass

class SerialReader:
    BITS_PER_BYTE = 10.
    def __init__(self, reactor, serialport, baud):
        self.reactor = reactor
        self.serialport = serialport
        self.baud = baud
        # Serial port
        self.ser = None
        self.msgparser = msgproto.MessageParser()
        # C interface
        self.ffi_main, self.ffi_lib = chelper.get_ffi()
        self.serialqueue = None
        self.default_cmd_queue = self.alloc_command_queue()
        self.stats_buf = self.ffi_main.new('char[4096]')
        # Threading
        self.lock = threading.Lock()
        self.background_thread = None
        # Message handlers
        handlers = {
            '#unknown': self.handle_unknown, '#output': self.handle_output,
            'shutdown': self.handle_output, 'is_shutdown': self.handle_output
        }
        self.handlers = { (k, None): v for k, v in handlers.items() }
    def _bg_thread(self):
        response = self.ffi_main.new('struct pull_queue_message *')
        while 1:
            self.ffi_lib.serialqueue_pull(self.serialqueue, response)
            count = response.len
            if count <= 0:
                break
            params = self.msgparser.parse(response.msg[0:count])
            params['#sent_time'] = response.sent_time
            params['#receive_time'] = response.receive_time
            hdl = (params['#name'], params.get('oid'))
            with self.lock:
                hdl = self.handlers.get(hdl, self.handle_default)
            try:
                hdl(params)
            except:
                logging.exception("Exception in serial callback")
    def connect(self):
        # Initial connection
        logging.info("Starting serial connect")
        while 1:
            starttime = self.reactor.monotonic()
            try:
                if self.baud:
                    self.ser = serial.Serial(
                        self.serialport, self.baud, timeout=0)
                else:
                    self.ser = open(self.serialport, 'rb+')
            except (OSError, IOError, serial.SerialException) as e:
                logging.warn("Unable to open port: %s", e)
                self.reactor.pause(starttime + 5.)
                continue
            if self.baud:
                stk500v2_leave(self.ser, self.reactor)
            self.serialqueue = self.ffi_lib.serialqueue_alloc(
                self.ser.fileno(), 0)
            self.background_thread = threading.Thread(target=self._bg_thread)
            self.background_thread.start()
            # Obtain and load the data dictionary from the firmware
            sbs = SerialBootStrap(self)
            identify_data = sbs.get_identify_data(starttime + 5.)
            if identify_data is None:
                logging.warn("Timeout on serial connect")
                self.disconnect()
                continue
            break
        msgparser = msgproto.MessageParser()
        msgparser.process_identify(identify_data)
        self.msgparser = msgparser
        self.register_callback(self.handle_unknown, '#unknown')
        # Setup baud adjust
        mcu_baud = msgparser.get_constant_float('SERIAL_BAUD', None)
        if mcu_baud is not None:
            baud_adjust = self.BITS_PER_BYTE / mcu_baud
            self.ffi_lib.serialqueue_set_baud_adjust(
                self.serialqueue, baud_adjust)
        receive_window = msgparser.get_constant_int('RECEIVE_WINDOW', None)
        if receive_window is not None:
            self.ffi_lib.serialqueue_set_receive_window(
                self.serialqueue, receive_window)
    def connect_file(self, debugoutput, dictionary, pace=False):
        self.ser = debugoutput
        self.msgparser.process_identify(dictionary, decompress=False)
        self.serialqueue = self.ffi_lib.serialqueue_alloc(self.ser.fileno(), 1)
    def set_clock_est(self, freq, last_time, last_clock):
        self.ffi_lib.serialqueue_set_clock_est(
            self.serialqueue, freq, last_time, last_clock)
    def disconnect(self):
        if self.serialqueue is not None:
            self.ffi_lib.serialqueue_exit(self.serialqueue)
            if self.background_thread is not None:
                self.background_thread.join()
            self.ffi_lib.serialqueue_free(self.serialqueue)
            self.background_thread = self.serialqueue = None
        if self.ser is not None:
            self.ser.close()
            self.ser = None
    def stats(self, eventtime):
        if self.serialqueue is None:
            return ""
        self.ffi_lib.serialqueue_get_stats(
            self.serialqueue, self.stats_buf, len(self.stats_buf))
        return self.ffi_main.string(self.stats_buf)
    # Serial response callbacks
    def register_callback(self, callback, name, oid=None):
        with self.lock:
            self.handlers[name, oid] = callback
    def unregister_callback(self, name, oid=None):
        with self.lock:
            del self.handlers[name, oid]
    # Command sending
    def raw_send(self, cmd, minclock, reqclock, cmd_queue):
        self.ffi_lib.serialqueue_send(
            self.serialqueue, cmd_queue, cmd, len(cmd), minclock, reqclock)
    def send(self, msg, minclock=0, reqclock=0):
        cmd = self.msgparser.create_command(msg)
        self.raw_send(cmd, minclock, reqclock, self.default_cmd_queue)
    def lookup_command(self, msgformat, cq=None):
        if cq is None:
            cq = self.default_cmd_queue
        cmd = self.msgparser.lookup_command(msgformat)
        return SerialCommand(self, cq, cmd)
    def alloc_command_queue(self):
        return self.ffi_main.gc(self.ffi_lib.serialqueue_alloc_commandqueue(),
                                self.ffi_lib.serialqueue_free_commandqueue)
    # Dumping debug lists
    def dump_debug(self):
        out = []
        out.append("Dumping serial stats: %s" % (
            self.stats(self.reactor.monotonic()),))
        sdata = self.ffi_main.new('struct pull_queue_message[1024]')
        rdata = self.ffi_main.new('struct pull_queue_message[1024]')
        scount = self.ffi_lib.serialqueue_extract_old(
            self.serialqueue, 1, sdata, len(sdata))
        rcount = self.ffi_lib.serialqueue_extract_old(
            self.serialqueue, 0, rdata, len(rdata))
        out.append("Dumping send queue %d messages" % (scount,))
        for i in range(scount):
            msg = sdata[i]
            cmds = self.msgparser.dump(msg.msg[0:msg.len])
            out.append("Sent %d %f %f %d: %s" % (
                i, msg.receive_time, msg.sent_time, msg.len, ', '.join(cmds)))
        out.append("Dumping receive queue %d messages" % (rcount,))
        for i in range(rcount):
            msg = rdata[i]
            cmds = self.msgparser.dump(msg.msg[0:msg.len])
            out.append("Receive: %d %f %f %d: %s" % (
                i, msg.receive_time, msg.sent_time, msg.len, ', '.join(cmds)))
        return '\n'.join(out)
    # Default message handlers
    def handle_unknown(self, params):
        logging.warn("Unknown message type %d: %s",
                     params['#msgid'], repr(params['#msg']))
    def handle_output(self, params):
        logging.info("%s: %s", params['#name'], params['#msg'])
    def handle_default(self, params):
        logging.warn("got %s", params)
    def __del__(self):
        self.disconnect()

# Wrapper around command sending
class SerialCommand:
    def __init__(self, serial, cmd_queue, cmd):
        self.serial = serial
        self.cmd_queue = cmd_queue
        self.cmd = cmd
    def send(self, data=(), minclock=0, reqclock=0):
        cmd = self.cmd.encode(data)
        self.serial.raw_send(cmd, minclock, reqclock, self.cmd_queue)
    def send_with_response(self, data=(), response=None, response_oid=None):
        cmd = self.cmd.encode(data)
        src = SerialRetryCommand(self.serial, cmd, response, response_oid)
        return src.get_response()

# Class to retry sending of a query command until a given response is received
class SerialRetryCommand:
    TIMEOUT_TIME = 5.0
    RETRY_TIME = 0.500
    def __init__(self, serial, cmd, name, oid=None):
        self.serial = serial
        self.cmd = cmd
        self.name = name
        self.oid = oid
        self.response = None
        self.min_query_time = self.serial.reactor.monotonic()
        self.serial.register_callback(self.handle_callback, self.name, self.oid)
        self.send_timer = self.serial.reactor.register_timer(
            self.send_event, self.serial.reactor.NOW)
    def unregister(self):
        self.serial.unregister_callback(self.name, self.oid)
        self.serial.reactor.unregister_timer(self.send_timer)
    def send_event(self, eventtime):
        if self.response is not None:
            return self.serial.reactor.NEVER
        self.serial.raw_send(self.cmd, 0, 0, self.serial.default_cmd_queue)
        return eventtime + self.RETRY_TIME
    def handle_callback(self, params):
        last_sent_time = params['#sent_time']
        if last_sent_time >= self.min_query_time:
            self.response = params
    def get_response(self):
        eventtime = self.serial.reactor.monotonic()
        while self.response is None:
            eventtime = self.serial.reactor.pause(eventtime + 0.05)
            if eventtime > self.min_query_time + self.TIMEOUT_TIME:
                self.unregister()
                raise error("Timeout on wait for '%s' response" % (self.name,))
        self.unregister()
        return self.response

# Code to start communication and download message type dictionary
class SerialBootStrap:
    RETRY_TIME = 0.500
    def __init__(self, serial):
        self.serial = serial
        self.identify_data = ""
        self.identify_cmd = self.serial.lookup_command(
            "identify offset=%u count=%c")
        self.is_done = False
        self.serial.register_callback(self.handle_identify, 'identify_response')
        self.serial.register_callback(self.handle_unknown, '#unknown')
        self.send_timer = self.serial.reactor.register_timer(
            self.send_event, self.serial.reactor.NOW)
    def get_identify_data(self, timeout):
        eventtime = self.serial.reactor.monotonic()
        while not self.is_done and eventtime <= timeout:
            eventtime = self.serial.reactor.pause(eventtime + 0.05)
        self.serial.unregister_callback('identify_response')
        self.serial.reactor.unregister_timer(self.send_timer)
        if not self.is_done:
            return None
        return self.identify_data
    def handle_identify(self, params):
        if self.is_done or params['offset'] != len(self.identify_data):
            return
        msgdata = params['data']
        if not msgdata:
            self.is_done = True
            return
        self.identify_data += msgdata
        self.identify_cmd.send([len(self.identify_data), 40])
    def send_event(self, eventtime):
        if self.is_done:
            return self.serial.reactor.NEVER
        self.identify_cmd.send([len(self.identify_data), 40])
        return eventtime + self.RETRY_TIME
    def handle_unknown(self, params):
        logging.debug("Unknown message %d (len %d) while identifying",
                      params['#msgid'], len(params['#msg']))

# Attempt to place an AVR stk500v2 style programmer into normal mode
def stk500v2_leave(ser, reactor):
    logging.debug("Starting stk500v2 leave programmer sequence")
    util.clear_hupcl(ser.fileno())
    origbaud = ser.baudrate
    # Request a dummy speed first as this seems to help reset the port
    ser.baudrate = 2400
    ser.read(1)
    # Send stk500v2 leave programmer sequence
    ser.baudrate = 115200
    reactor.pause(reactor.monotonic() + 0.100)
    ser.read(4096)
    ser.write('\x1b\x01\x00\x01\x0e\x11\x04')
    reactor.pause(reactor.monotonic() + 0.050)
    res = ser.read(4096)
    logging.debug("Got %s from stk500v2", repr(res))
    ser.baudrate = origbaud

# Attempt an arduino style reset on a serial port
def arduino_reset(serialport, reactor):
    # First try opening the port at a different baud
    ser = serial.Serial(serialport, 2400, timeout=0)
    ser.read(1)
    reactor.pause(reactor.monotonic() + 0.100)
    # Then toggle DTR
    ser.dtr = True
    reactor.pause(reactor.monotonic() + 0.100)
    ser.dtr = False
    reactor.pause(reactor.monotonic() + 0.100)
    ser.close()