heater_fan: log a warning if pin is non among initial pins

This will poke a user towards configuring it as a safety measure,
i.e. cooling the heater if a restart fails.

Example output:
`Heater fan's pin '!PA1' is not among initial pins of MCU 'toolhead'.
Consider adding it for safety.`

Signed-off-by: Kamil Domański <[email protected]>

klippy/extras/heater_fan.py

@@ -3,6 +3,7 @@
 # Copyright (C) 2016-2020  Kevin O'Connor <[email protected]>
 #
 # This file may be distributed under the terms of the GNU GPLv3 license.
+import logging
 from . import fan
 
 PIN_MIN_TIME = 0.100
@@ -19,6 +20,11 @@ def __init__(self, config):
         self.fan_speed = config.getfloat("fan_speed", 1., minval=0., maxval=1.)
         self.last_speed = 0.
     def handle_ready(self):
+        if not self.fan.mcu_fan.is_initial_pin():
+            logging.warning(
+                "Heater fan's pin '%s' is not among initial pins of MCU '%s'. "
+                "Consider adding it for safety."
+                % (self.fan.mcu_fan.raw_pin_string(), self.fan.get_mcu()._name))
         pheaters = self.printer.lookup_object('heaters')
         self.heaters = [pheaters.lookup_heater(n) for n in self.heater_names]
         reactor = self.printer.get_reactor()

klippy/mcu.py

@@ -384,6 +384,17 @@ def __init__(self, mcu, pin_params):
         self._last_clock = 0
         self._pwm_max = 0.
         self._set_cmd = None
+    def raw_pin_string(self):
+        ppins = self._mcu._printer.lookup_object('pins')
+        pin_resolver = ppins.get_pin_resolver(self._mcu._name)
+        pin_real_name = pin_resolver.aliases.get(self._pin, self._pin)
+        if self._invert:
+            return '!'+pin_real_name
+        else:
+            return pin_real_name
+    def is_initial_pin(self):
+        initial_pins = self._mcu.get_constants().get('INITIAL_PINS', '')
+        return (self.raw_pin_string() in initial_pins.split(','))
     def get_mcu(self):
         return self._mcu
     def setup_max_duration(self, max_duration):