klippy: Support FIRMWARE_RESTART command

Add initial support for micro-controller resets via the Arduino reset
mechanism.  Also, automatically attempt a firmware restart if the
printer CRC does not match.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

5 files changed, 70 insertions, 24 deletions

diff --git a/docs/Todo.md b/docs/Todo.md
index e16196e1..3237fe64 100644
--- a/docs/Todo.md
+++ b/docs/Todo.md
@@ -14,8 +14,6 @@ Host user interaction
  * Provide startup scripts so that Klippy can startup at system
    bootup.
 
- * Allow loading of a new config without having to restart the mcu.
-
 * Improve gcode interface:
 
  * Provide a better way to handle print nozzle z offsets. The M206
diff --git a/klippy/gcode.py b/klippy/gcode.py
index ce3c3ffe..e0bf6aa9 100644
--- a/klippy/gcode.py
+++ b/klippy/gcode.py
@@ -46,8 +46,8 @@ class GCodeParser:
         handlers = ['G1', 'G4', 'G20', 'G21', 'G28', 'G90', 'G91', 'G92',
                     'M18', 'M82', 'M83', 'M105', 'M110', 'M112', 'M114', 'M115',
                     'M206', 'M400',
-                    'HELP', 'QUERY_ENDSTOPS', 'RESTART', 'CLEAR_SHUTDOWN',
-                    'STATUS']
+                    'HELP', 'QUERY_ENDSTOPS', 'CLEAR_SHUTDOWN',
+                    'RESTART', 'FIRMWARE_RESTART', 'STATUS']
         if self.heater_nozzle is not None:
             handlers.extend(['M104', 'M109', 'PID_TUNE'])
         if self.heater_bed is not None:
@@ -119,7 +119,7 @@ class GCodeParser:
                 self.toolhead.force_shutdown()
                 self.respond_error('Internal error on command:"%s"' % (cmd,))
                 if self.is_fileinput:
-                    self.printer.request_exit_eof()
+                    self.printer.request_exit('exit_eof')
                     break
             self.ack()
     def process_data(self, eventtime):
@@ -144,7 +144,7 @@ class GCodeParser:
             self.fd_handle = self.reactor.register_fd(self.fd, self.process_data)
         if not data and self.is_fileinput:
             self.motor_heater_off()
-            self.printer.request_exit_eof()
+            self.printer.request_exit('exit_eof')
     # Response handling
     def ack(self, msg=None):
         if not self.need_ack or self.is_fileinput:
@@ -373,16 +373,23 @@ class GCodeParser:
             self.cmd_default(params)
             return
         self.printer.mcu.clear_shutdown()
-        self.printer.request_restart()
-    cmd_RESTART_when_not_ready = True
-    cmd_RESTART_help = "Reload config file and restart host software"
-    def cmd_RESTART(self, params):
+        self.printer.request_exit('restart')
+    def prep_restart(self):
         if self.is_printer_ready:
             self.respond_info("Preparing to restart...")
             self.motor_heater_off()
             self.toolhead.dwell(0.500)
             self.toolhead.wait_moves()
-        self.printer.request_restart()
+    cmd_RESTART_when_not_ready = True
+    cmd_RESTART_help = "Reload config file and restart host software"
+    def cmd_RESTART(self, params):
+        self.prep_restart()
+        self.printer.request_exit('restart')
+    cmd_FIRMWARE_RESTART_when_not_ready = True
+    cmd_FIRMWARE_RESTART_help = "Restart firmware, host, and reload config"
+    def cmd_FIRMWARE_RESTART(self, params):
+        self.prep_restart()
+        self.printer.request_exit('firmware_restart')
     cmd_STATUS_when_not_ready = True
     cmd_STATUS_help = "Report the printer status"
     def cmd_STATUS(self, params):
diff --git a/klippy/klippy.py b/klippy/klippy.py
index abd92208..412477ad 100644
--- a/klippy/klippy.py
+++ b/klippy/klippy.py
@@ -32,9 +32,9 @@ Protocol error connecting to printer
 """
 
 message_mcu_connect_error = """
-This is an unrecoverable error.  Please manually restart the
-micro-controller and then issue the "RESTART" command to
-restart the host software.
+Once the underlying issue is corrected, use the
+"FIRMWARE_RESTART" command to reset the firmware, reload the
+config, and restart the host software.
 Error configuring printer
 """
 
@@ -94,8 +94,10 @@ class ConfigLogger():
         logging.info(data.strip())
 
 class Printer:
-    def __init__(self, conffile, input_fd, is_fileinput=False, version="?"):
+    def __init__(self, conffile, input_fd, startup_state
+                 , is_fileinput=False, version="?"):
         self.conffile = conffile
+        self.startup_state = startup_state
         self.software_version = version
         self.reactor = reactor.Reactor()
         self.gcode = gcode.GCodeParser(self, input_fd, is_fileinput)
@@ -226,11 +228,18 @@ class Printer:
                 self.mcu.disconnect()
         except:
             logging.exception("Unhandled exception during disconnect")
-    def request_restart(self):
-        self.run_result = "restart"
-        self.reactor.end()
-    def request_exit_eof(self):
-        self.run_result = "exit_eof"
+    def firmware_restart(self):
+        try:
+            if self.mcu is not None:
+                self.stats(self.reactor.monotonic())
+                self.mcu.disconnect()
+                self.mcu.microcontroller_restart()
+        except:
+            logging.exception("Unhandled exception during firmware_restart")
+    def get_startup_state(self):
+        return self.startup_state
+    def request_exit(self, result="exit"):
+        self.run_result = result
         self.reactor.end()
 
 
@@ -287,9 +296,11 @@ def main():
         logging.info("CPU: %s" % (util.get_cpu_info(),))
 
     # Start firmware
+    res = 'startup'
     while 1:
         is_fileinput = debuginput is not None
-        printer = Printer(conffile, input_fd, is_fileinput, software_version)
+        printer = Printer(
+            conffile, input_fd, res, is_fileinput, software_version)
         if debugoutput:
             proto_dict = read_dictionary(options.read_dictionary)
             printer.set_fileoutput(debugoutput, proto_dict)
@@ -299,6 +310,11 @@ def main():
             time.sleep(1.)
             logging.info("Restarting printer")
             continue
+        elif res == 'firmware_restart':
+            printer.firmware_restart()
+            time.sleep(1.)
+            logging.info("Restarting printer")
+            continue
         elif res == 'exit_eof':
             printer.disconnect()
         break
diff --git a/klippy/mcu.py b/klippy/mcu.py
index 73f99c54..7dae343a 100644
--- a/klippy/mcu.py
+++ b/klippy/mcu.py
@@ -336,8 +336,9 @@ class MCU:
         self._config = config
         # Serial port
         baud = config.getint('baud', 250000)
-        serialport = config.get('serial', '/dev/ttyS0')
-        self.serial = serialhdl.SerialReader(printer.reactor, serialport, baud)
+        self._serialport = config.get('serial', '/dev/ttyS0')
+        self.serial = serialhdl.SerialReader(
+            printer.reactor, self._serialport, baud)
         self.is_shutdown = False
         self._shutdown_msg = ""
         self._is_fileoutput = False
@@ -423,6 +424,10 @@ class MCU:
     def clear_shutdown(self):
         logging.info("Sending clear_shutdown command")
         self.send(self._clear_shutdown_cmd.encode())
+    def microcontroller_restart(self):
+        logging.info("Attempting a microcontroller reset")
+        self.disconnect()
+        serialhdl.arduino_reset(self._serialport, self._printer.reactor)
     def is_fileoutput(self):
         return self._is_fileoutput
     # Configuration phase
@@ -472,6 +477,7 @@ class MCU:
             config_params = self.serial.send_with_response(msg, 'config')
         if not config_params['is_config']:
             # Send config commands
+            logging.info("Sending printer configuration...")
             for c in self._config_cmds:
                 self.send(self.create_command(c))
             if not self._is_fileoutput:
@@ -482,6 +488,12 @@ class MCU:
                             self._shutdown_msg,))
                     raise error("Unable to configure printer")
         if self._config_crc != config_params['crc']:
+            if self._printer.get_startup_state() != 'firmware_restart':
+                # Attempt a firmware restart to fix the CRC error
+                logging.info(
+                    "Printer CRC mismatch - attempting firmware restart")
+                self._printer.request_exit('firmware_restart')
+                self._printer.reactor.pause(0.100)
             raise error("Printer CRC does not match config")
         move_count = config_params['move_count']
         logging.info("Configured (%d moves)" % (move_count,))
diff --git a/klippy/serialhdl.py b/klippy/serialhdl.py
index 1af64000..8112d703 100644
--- a/klippy/serialhdl.py
+++ b/klippy/serialhdl.py
@@ -3,7 +3,7 @@
 # Copyright (C) 2016  Kevin O'Connor <kevin@koconnor.net>
 #
 # This file may be distributed under the terms of the GNU GPLv3 license.
-import logging, threading
+import logging, threading, time
 import serial
 
 import msgproto, chelper, util
@@ -325,3 +325,16 @@ def stk500v2_leave(ser, reactor):
     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 1200 baud
+    ser = serial.Serial(serialport, 1200, timeout=0)
+    ser.read(1)
+    time.sleep(0.100)
+    # Then try toggling DTR
+    ser.dtr = True
+    time.sleep(0.100)
+    ser.dtr = False
+    time.sleep(0.100)
+    ser.close()