homing: Directly interact with the kinematic class when homing

Move the homing logic out of toolhead.py and into homing.py.  This
simplifies the toolhead logic and centralizes the homing code.

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

klippy/gcode.py

@@ -354,11 +354,11 @@ class GCodeParser:
                 axes.append(self.axis2pos[axis])
         if not axes:
             axes = [0, 1, 2]
-        homing_state = homing.Homing(self.toolhead, axes)
+        homing_state = homing.Homing(self.toolhead)
         if self.is_fileinput:
             homing_state.set_no_verify_retract()
         try:
-            self.toolhead.home(homing_state)
+            homing_state.home_axes(axes)
         except homing.EndstopError as e:
             raise error(str(e))
         newpos = self.toolhead.get_position()

klippy/homing.py

@@ -10,9 +10,9 @@ ENDSTOP_SAMPLE_TIME = .000015
 ENDSTOP_SAMPLE_COUNT = 4
 
 class Homing:
-    def __init__(self, toolhead, changed_axes):
+    def __init__(self, toolhead):
         self.toolhead = toolhead
-        self.changed_axes = changed_axes
+        self.changed_axes = []
         self.verify_retract = True
     def set_no_verify_retract(self):
         self.verify_retract = False
@@ -79,6 +79,13 @@ class Homing:
                 if s.get_mcu_position() == pos:
                     raise EndstopError(
                         "Endstop %s still triggered after retract" % (name,))
+    def home_axes(self, axes):
+        self.changed_axes = axes
+        try:
+            self.toolhead.get_kinematics().home(self)
+        except EndstopError:
+            self.toolhead.motor_off()
+            raise
 
 def query_endstops(print_time, query_flags, steppers):
     if query_flags == "get_mcu_position":

klippy/toolhead.py

@@ -327,12 +327,6 @@ class ToolHead:
         self.move_queue.add_move(move)
         if self.print_time > self.need_check_stall:
             self._check_stall()
-    def home(self, homing_state):
-        try:
-            self.kin.home(homing_state)
-        except homing.EndstopError as e:
-            self.motor_off()
-            raise
     def dwell(self, delay, check_stall=True):
         self.get_last_move_time()
         self.update_move_time(delay)
@@ -382,6 +376,8 @@ class ToolHead:
             self.reset_print_time()
         except:
             logging.exception("Exception in do_shutdown")
+    def get_kinematics(self):
+        return self.kin
     def get_max_velocity(self):
         return self.max_velocity, self.max_accel
     def get_max_axis_halt(self):