tmc: Track requested hold_current so SET_TMC_CURRENT doesn't reduce it

The code automatically reduces the hold_current so that it is no
greater than the run_current.  However, this could lead to confusing
behavior if one reduced and then increased the run_current via
SET_TMC_CURRENT commands.  To avoid that, this change adds support for
tracking the requested hold_current - thus changes to run_current
don't subtly alter the hold_current.

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

5 files changed, 20 insertions, 17 deletions

diff --git a/docs/Config_Reference.md b/docs/Config_Reference.md
index b8dd356e..fa5b6c76 100644
--- a/docs/Config_Reference.md
+++ b/docs/Config_Reference.md
@@ -2760,8 +2760,8 @@ run_current:
 #   during stepper movement. This parameter must be provided.
 #hold_current:
 #   The amount of current (in amps RMS) to configure the driver to use
-#   when the stepper is not moving. The default is to use the same
-#   value as run_current.
+#   when the stepper is not moving. The default is to not reduce the
+#   current.
 #sense_resistor: 0.110
 #   The resistance (in ohms) of the motor sense resistor. The default
 #   is 0.110 ohms.
diff --git a/klippy/extras/tmc.py b/klippy/extras/tmc.py
index d45d64ac..f13568ed 100644
--- a/klippy/extras/tmc.py
+++ b/klippy/extras/tmc.py
@@ -261,26 +261,25 @@ class TMCCommandHelper:
     cmd_SET_TMC_CURRENT_help = "Set the current of a TMC driver"
     def cmd_SET_TMC_CURRENT(self, gcmd):
         ch = self.current_helper
-        prev_run_current, prev_hold_current, max_current = ch.get_current()
-        run_current = gcmd.get_float('CURRENT', None,
-                                     minval=0., maxval=max_current)
+        prev_cur, prev_hold_cur, req_hold_cur, max_cur = ch.get_current()
+        run_current = gcmd.get_float('CURRENT', None, minval=0., maxval=max_cur)
         hold_current = gcmd.get_float('HOLDCURRENT', None,
-                                      above=0., maxval=max_current)
+                                      above=0., maxval=max_cur)
         if run_current is not None or hold_current is not None:
             if run_current is None:
-                run_current = prev_run_current
+                run_current = prev_cur
             if hold_current is None:
-                hold_current = prev_hold_current
+                hold_current = req_hold_cur
             toolhead = self.printer.lookup_object('toolhead')
             print_time = toolhead.get_last_move_time()
             ch.set_current(run_current, hold_current, print_time)
-            prev_run_current, prev_hold_current, max_current = ch.get_current()
+            prev_cur, prev_hold_cur, req_hold_cur, max_cur = ch.get_current()
         # Report values
-        if prev_hold_current is None:
-            gcmd.respond_info("Run Current: %0.2fA" % (prev_run_current,))
+        if prev_hold_cur is None:
+            gcmd.respond_info("Run Current: %0.2fA" % (prev_cur,))
         else:
             gcmd.respond_info("Run Current: %0.2fA Hold Current: %0.2fA"
-                              % (prev_run_current, prev_hold_current))
+                              % (prev_cur, prev_hold_cur))
     # Stepper phase tracking
     def _get_phases(self):
         return (256 >> self.fields.get_field("mres")) * 4
diff --git a/klippy/extras/tmc2130.py b/klippy/extras/tmc2130.py
index c29622ec..c6a54561 100644
--- a/klippy/extras/tmc2130.py
+++ b/klippy/extras/tmc2130.py
@@ -103,8 +103,9 @@ class TMCCurrentHelper:
         self.fields = mcu_tmc.get_fields()
         run_current = config.getfloat('run_current',
                                       above=0., maxval=MAX_CURRENT)
-        hold_current = config.getfloat('hold_current', run_current,
+        hold_current = config.getfloat('hold_current', MAX_CURRENT,
                                        above=0., maxval=MAX_CURRENT)
+        self.req_hold_current = hold_current
         self.sense_resistor = config.getfloat('sense_resistor', 0.110, above=0.)
         vsense, irun, ihold = self._calc_current(run_current, hold_current)
         self.fields.set_field("vsense", vsense)
@@ -139,8 +140,9 @@ class TMCCurrentHelper:
     def get_current(self):
         run_current = self._calc_current_from_field("irun")
         hold_current = self._calc_current_from_field("ihold")
-        return run_current, hold_current, MAX_CURRENT
+        return run_current, hold_current, self.req_hold_current, MAX_CURRENT
     def set_current(self, run_current, hold_current, print_time):
+        self.req_hold_current = hold_current
         vsense, irun, ihold = self._calc_current(run_current, hold_current)
         if vsense != self.fields.get_field("vsense"):
             val = self.fields.set_field("vsense", vsense)
diff --git a/klippy/extras/tmc2660.py b/klippy/extras/tmc2660.py
index 52aa2e42..f55f6f01 100644
--- a/klippy/extras/tmc2660.py
+++ b/klippy/extras/tmc2660.py
@@ -169,7 +169,7 @@ class TMC2660CurrentHelper:
             self.mcu_tmc.set_register("DRVCONF", val, print_time)
 
     def get_current(self):
-        return self.current, None, MAX_CURRENT
+        return self.current, None, None, MAX_CURRENT
 
     def set_current(self, run_current, hold_current, print_time):
         self.current = run_current
diff --git a/klippy/extras/tmc5160.py b/klippy/extras/tmc5160.py
index fae17226..4d970271 100644
--- a/klippy/extras/tmc5160.py
+++ b/klippy/extras/tmc5160.py
@@ -235,8 +235,9 @@ class TMC5160CurrentHelper:
         self.fields = mcu_tmc.get_fields()
         run_current = config.getfloat('run_current',
                                       above=0., maxval=MAX_CURRENT)
-        hold_current = config.getfloat('hold_current', run_current,
+        hold_current = config.getfloat('hold_current', MAX_CURRENT,
                                        above=0., maxval=MAX_CURRENT)
+        self.req_hold_current = hold_current
         self.sense_resistor = config.getfloat('sense_resistor', 0.075, above=0.)
         self._set_globalscaler(run_current)
         irun, ihold = self._calc_current(run_current, hold_current)
@@ -271,8 +272,9 @@ class TMC5160CurrentHelper:
     def get_current(self):
         run_current = self._calc_current_from_field("irun")
         hold_current = self._calc_current_from_field("ihold")
-        return run_current, hold_current, MAX_CURRENT
+        return run_current, hold_current, self.req_hold_current, MAX_CURRENT
     def set_current(self, run_current, hold_current, print_time):
+        self.req_hold_current = hold_current
         irun, ihold = self._calc_current(run_current, hold_current)
         self.fields.set_field("ihold", ihold)
         val = self.fields.set_field("irun", irun)