stepper_enable: Move enable tracking from stepper.py to stepper_enable.py

Move the enable line tracking out of the main stepper.py code.  This
simplifies the main kinematic code.

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

klippy/extras/stepper_enable.py

@@ -7,24 +7,86 @@ import logging
 
 DISABLE_STALL_TIME = 0.100
 
-class StepperEnable:
+# Tracking of shared stepper enable pins
+class StepperEnablePin:
+    def __init__(self, mcu_enable, enable_count=0):
+        self.mcu_enable = mcu_enable
+        self.enable_count = enable_count
+    def set_enable(self, print_time):
+        if not self.enable_count:
+            self.mcu_enable.set_digital(print_time, 1)
+        self.enable_count += 1
+    def set_disable(self, print_time):
+        self.enable_count -= 1
+        if not self.enable_count:
+            self.mcu_enable.set_digital(print_time, 0)
+
+# Automatic multiple pin enable lines
+class StepperMultiEnablePin:
+    def __init__(self, enable_list):
+        self.enable_list = enable_list
+    def set_enable(self, print_time):
+        for en in self.enable_list:
+            en.set_enable(print_time)
+    def set_disable(self, print_time):
+        for en in self.enable_list:
+            en.set_disable(print_time)
+
+# Resolve the 'enable_pin' stepper config setting
+def lookup_enable_pin(ppins, pin_list):
+    if pin_list is None:
+        return StepperEnablePin(None, 9999)
+    enable_list = []
+    for pin in pin_list.split(','):
+        pin_params = ppins.lookup_pin(pin, can_invert=True,
+                                      share_type='stepper_enable')
+        enable = pin_params.get('class')
+        if enable is None:
+            mcu_enable = pin_params['chip'].setup_pin('digital_out', pin_params)
+            mcu_enable.setup_max_duration(0.)
+            pin_params['class'] = enable = StepperEnablePin(mcu_enable)
+        enable_list.append(enable)
+    if len(enable_list) == 1:
+        return enable_list[0]
+    return StepperMultiEnablePin(enable_list)
+
+# Enable line tracking for each stepper motor
+class EnableTracking:
+    def __init__(self, printer, stepper, pin):
+        self.stepper = stepper
+        self.is_motor_enabled = False
+        self.stepper.add_active_callback(self.motor_enable)
+        self.enable = lookup_enable_pin(printer.lookup_object('pins'), pin)
+    def motor_enable(self, print_time):
+        if not self.is_motor_enabled:
+            self.enable.set_enable(print_time)
+            self.is_motor_enabled = True
+    def motor_disable(self, print_time):
+        if self.is_motor_enabled:
+            # Enable stepper on future stepper movement
+            self.enable.set_disable(print_time)
+            self.is_motor_enabled = False
+            self.stepper.add_active_callback(self.motor_enable)
+
+class PrinterStepperEnable:
     def __init__(self, config):
         self.printer = config.get_printer()
-        self.steppers = {}
+        self.enable_lines = {}
         self.printer.register_event_handler("gcode:request_restart",
                                             self._handle_request_restart)
         # Register M18/M84 commands
         gcode = self.printer.lookup_object('gcode')
         gcode.register_command("M18", self.cmd_M18)
         gcode.register_command("M84", self.cmd_M18)
-    def register_stepper(self, stepper):
-        self.steppers[stepper.get_name()] = stepper
+    def register_stepper(self, stepper, pin):
+        name = stepper.get_name()
+        self.enable_lines[name] = EnableTracking(self.printer, stepper, pin)
     def motor_off(self):
         toolhead = self.printer.lookup_object('toolhead')
         toolhead.dwell(DISABLE_STALL_TIME)
         print_time = toolhead.get_last_move_time()
-        for s in self.steppers.values():
-            s.motor_enable(print_time, 0)
+        for el in self.enable_lines.values():
+            el.motor_disable(print_time)
         self.printer.send_event("stepper_enable:motor_off", print_time)
         toolhead.dwell(DISABLE_STALL_TIME)
         logging.debug('; Max time of %f', print_time)
@@ -33,6 +95,12 @@ class StepperEnable:
     def cmd_M18(self, params):
         # Turn off motors
         self.motor_off()
+    def is_motor_enabled(self, name):
+        return self.enable_lines[name].is_motor_enabled
+    def motor_enable(self, name, print_time):
+        self.enable_lines[name].motor_enable(print_time)
+    def motor_disable(self, name, print_time):
+        self.enable_lines[name].motor_disable(print_time)
 
 def load_config(config):
-    return StepperEnable(config)
+    return PrinterStepperEnable(config)