tmc: Refactor TMCtstepHelper()

Update TMCtstepHelper() to obtain the step_distance, tmc_frequency,
and mres fields directly.

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

klippy/extras/tmc.py

@@ -330,15 +330,16 @@ def cmd_SET_TMC_FIELD(self, gcmd):
             raise gcmd.error("Unknown field name '%s'" % (field_name,))
         value = gcmd.get_int("VALUE", None)
         velocity = gcmd.get_float("VELOCITY", None, minval=0.0)
-        tmc_frequency = self.mcu_tmc.get_tmc_frequency()
-        if tmc_frequency is None and velocity is not None:
-            raise gcmd.error("VELOCITY parameter not supported by this driver")
         if (value is None) == (velocity is None):
             raise gcmd.error("Specify either VALUE or VELOCITY")
         if velocity is not None:
-            step_dist = self.stepper.get_step_dist()
-            mres = self.fields.get_field("mres")
-            value = TMCtstepHelper(step_dist, mres, tmc_frequency, velocity)
+            if self.mcu_tmc.get_tmc_frequency() is None:
+                raise gcmd.error(
+                    "VELOCITY parameter not supported by this driver"
+                )
+            value = TMCtstepHelper(
+                self.mcu_tmc, velocity, pstepper=self.stepper
+            )
         reg_val = self.fields.set_field(field_name, value)
         print_time = self.printer.lookup_object("toolhead").get_last_move_time()
         self.mcu_tmc.set_register(reg_name, reg_val, print_time)
@@ -725,13 +726,21 @@ def TMCMicrostepHelper(config, mcu_tmc):
 
 
 # Helper for calculating TSTEP based values from velocity
-def TMCtstepHelper(step_dist, mres, tmc_freq, velocity):
-    if velocity > 0.0:
-        step_dist_256 = step_dist / (1 << mres)
-        threshold = int(tmc_freq * step_dist_256 / velocity + 0.5)
-        return max(0, min(0xFFFFF, threshold))
-    else:
+def TMCtstepHelper(mcu_tmc, velocity, pstepper=None, config=None):
+    if velocity <= 0.0:
         return 0xFFFFF
+    if pstepper is not None:
+        step_dist = pstepper.get_step_dist()
+    else:
+        stepper_name = " ".join(config.get_name().split()[1:])
+        sconfig = config.getsection(stepper_name)
+        rotation_dist, steps_per_rotation = stepper.parse_step_distance(sconfig)
+        step_dist = rotation_dist / steps_per_rotation
+    mres = mcu_tmc.get_fields().get_field("mres")
+    step_dist_256 = step_dist / (1 << mres)
+    tmc_freq = mcu_tmc.get_tmc_frequency()
+    threshold = int(tmc_freq * step_dist_256 / velocity + 0.5)
+    return max(0, min(0xFFFFF, threshold))
 
 
 # Helper to configure stealthChop-spreadCycle transition velocity
@@ -743,13 +752,7 @@ def TMCStealthchopHelper(config, mcu_tmc, tmc_freq):
 
     if velocity is not None:
         en_pwm_mode = True
-
-        stepper_name = " ".join(config.get_name().split()[1:])
-        sconfig = config.getsection(stepper_name)
-        rotation_dist, steps_per_rotation = stepper.parse_step_distance(sconfig)
-        step_dist = rotation_dist / steps_per_rotation
-        mres = fields.get_field("mres")
-        tpwmthrs = TMCtstepHelper(step_dist, mres, tmc_freq, velocity)
+        tpwmthrs = TMCtstepHelper(mcu_tmc, velocity, config=config)
     fields.set_field("tpwmthrs", tpwmthrs)
 
     reg = fields.lookup_register("en_pwm_mode", None)
@@ -858,3 +861,24 @@ def set_current(self, new_current, hold_current, print_time, force=False):
 
         self.set_actual_current(new_current)
         self.apply_current(print_time)
+
+
+# Helper to configure StallGuard and CoolStep minimum velocity
+def TMCVcoolthrsHelper(config, mcu_tmc):
+    fields = mcu_tmc.get_fields()
+    velocity = config.getfloat("coolstep_threshold", None, minval=0.0)
+    tcoolthrs = 0
+    if velocity is not None:
+        tcoolthrs = TMCtstepHelper(mcu_tmc, velocity, config=config)
+    fields.set_field("tcoolthrs", tcoolthrs)
+
+
+# Helper to configure StallGuard and CoolStep maximum velocity and
+# SpreadCycle-FullStepping (High velocity) mode threshold.
+def TMCVhighHelper(config, mcu_tmc):
+    fields = mcu_tmc.get_fields()
+    velocity = config.getfloat("high_velocity_threshold", None, minval=0.0)
+    thigh = 0
+    if velocity is not None:
+        thigh = TMCtstepHelper(mcu_tmc, velocity, config=config)
+    fields.set_field("thigh", thigh)