stepper: Add support for stepping on both edges of a step pulse

Add an optimized step function for drivers that support stepping on
both rising and falling edges of the step pin.  Enable this
optimization on 32bit ARM micro-controllers.  Automatically detect
this capability in the host code and enable on TMC drivers running in
SPI/UART mode.

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

3 files changed, 27 insertions, 5 deletions

diff --git a/klippy/extras/tmc.py b/klippy/extras/tmc.py
index 7a6b4fa5..6a59bbfb 100644
--- a/klippy/extras/tmc.py
+++ b/klippy/extras/tmc.py
@@ -224,6 +224,8 @@ class TMCCommandHelper:
         self.stepper_enable = self.printer.load_object(config, "stepper_enable")
         self.printer.register_event_handler("stepper:sync_mcu_position",
                                             self._handle_sync_mcu_pos)
+        self.printer.register_event_handler("klippy:mcu_identify",
+                                            self._handle_mcu_identify)
         self.printer.register_event_handler("klippy:connect",
                                             self._handle_connect)
         # Set microstep config options
@@ -345,6 +347,12 @@ class TMCCommandHelper:
             self.echeck_helper.stop_checks()
         except self.printer.command_error as e:
             self.printer.invoke_shutdown(str(e))
+    def _handle_mcu_identify(self):
+        # Lookup stepper object
+        force_move = self.printer.lookup_object("force_move")
+        self.stepper = force_move.lookup_stepper(self.stepper_name)
+        # Note pulse duration and step_both_edge optimizations available
+        self.stepper.setup_default_pulse_duration(.000000100, True)
     def _handle_stepper_enable(self, print_time, is_enable):
         if is_enable:
             cb = (lambda ev: self._do_enable(print_time))
@@ -352,9 +360,10 @@ class TMCCommandHelper:
             cb = (lambda ev: self._do_disable(print_time))
         self.printer.get_reactor().register_callback(cb)
     def _handle_connect(self):
-        # Lookup stepper object
-        force_move = self.printer.lookup_object("force_move")
-        self.stepper = force_move.lookup_stepper(self.stepper_name)
+        # Check if using step on both edges optimization
+        pulse_duration, step_both_edge = self.stepper.get_pulse_duration()
+        if step_both_edge:
+            self.fields.set_field("dedge", 1)
         # Check for soft stepper enable/disable
         enable_line = self.stepper_enable.lookup_enable(self.stepper_name)
         enable_line.register_state_callback(self._handle_stepper_enable)
diff --git a/klippy/extras/tmc2660.py b/klippy/extras/tmc2660.py
index f55f6f01..c0d8fa9b 100644
--- a/klippy/extras/tmc2660.py
+++ b/klippy/extras/tmc2660.py
@@ -98,7 +98,6 @@ SignedFields = ["sgt"]
 
 FieldFormatters = dict(tmc2130.FieldFormatters)
 FieldFormatters.update({
-    "dedge": (lambda v: "1(Both Edges Active!)" if v else ""),
     "chm": (lambda v: "1(constant toff)" if v else "0(spreadCycle)"),
     "vsense": (lambda v: "1(165mV)" if v else "0(305mV)"),
     "sdoff": (lambda v: "1(Step/Dir disabled!)" if v else ""),
diff --git a/klippy/stepper.py b/klippy/stepper.py
index c5f81382..2e6655ef 100644
--- a/klippy/stepper.py
+++ b/klippy/stepper.py
@@ -32,6 +32,7 @@ class MCU_stepper:
                 "Stepper dir pin must be on same mcu as step pin")
         self._dir_pin = dir_pin_params['pin']
         self._invert_dir = dir_pin_params['invert']
+        self._step_both_edge = self._req_step_both_edge = False
         self._mcu_position_offset = 0.
         self._reset_cmd_tag = self._get_position_cmd = None
         self._active_callbacks = []
@@ -54,6 +55,12 @@ class MCU_stepper:
     def units_in_radians(self):
         # Returns true if distances are in radians instead of millimeters
         return self._units_in_radians
+    def get_pulse_duration(self):
+        return self._step_pulse_duration, self._step_both_edge
+    def setup_default_pulse_duration(self, pulse_duration, step_both_edge):
+        if self._step_pulse_duration is None:
+            self._step_pulse_duration = pulse_duration
+        self._req_step_both_edge = step_both_edge
     def setup_itersolve(self, alloc_func, *params):
         ffi_main, ffi_lib = chelper.get_ffi()
         sk = ffi_main.gc(getattr(ffi_lib, alloc_func)(*params), ffi_lib.free)
@@ -61,11 +68,18 @@ class MCU_stepper:
     def _build_config(self):
         if self._step_pulse_duration is None:
             self._step_pulse_duration = .000002
+        invert_step = self._invert_step
+        sbe = int(self._mcu.get_constants().get('STEPPER_BOTH_EDGE', '0'))
+        if self._req_step_both_edge and sbe:
+            # Enable stepper optimized step on both edges
+            self._step_both_edge = True
+            self._step_pulse_duration = 0.
+            invert_step = -1
         step_pulse_ticks = self._mcu.seconds_to_clock(self._step_pulse_duration)
         self._mcu.add_config_cmd(
             "config_stepper oid=%d step_pin=%s dir_pin=%s invert_step=%d"
             " step_pulse_ticks=%u" % (self._oid, self._step_pin, self._dir_pin,
-                                      self._invert_step, step_pulse_ticks))
+                                      invert_step, step_pulse_ticks))
         self._mcu.add_config_cmd("reset_step_clock oid=%d clock=0"
                                  % (self._oid,), on_restart=True)
         step_cmd_tag = self._mcu.lookup_command_tag(