tmc2240: Adding UART interface support to tmc2240 (#6305)

Signed-off-by:  Christoph Frei <[email protected]>

docs/Config_Reference.md

@@ -3442,7 +3442,7 @@ run_current:
 
 ### [tmc2240]
 
-Configure a TMC2240 stepper motor driver via SPI bus. To use this
+Configure a TMC2240 stepper motor driver via SPI bus or UART. To use this
 feature, define a config section with a "tmc2240" prefix followed by
 the name of the corresponding stepper config section (for example,
 "[tmc2240 stepper_x]").
@@ -3460,6 +3460,9 @@ cs_pin:
 #spi_software_miso_pin:
 #   See the "common SPI settings" section for a description of the
 #   above parameters.
+#uart_pin:
+#   The pin connected to the TMC2240 DIAG1/SW line. If this parameter
+#   is provided UART communication is used rather then SPI.
 #chain_position:
 #chain_length:
 #   These parameters configure an SPI daisy chain. The two parameters

klippy/extras/tmc2240.py

@@ -5,7 +5,7 @@
 #
 # This file may be distributed under the terms of the GNU GPLv3 license.
 import math, logging
-from . import bus, tmc, tmc2130
+from . import bus, tmc, tmc2130, tmc_uart
 
 TMC_FREQUENCY=12500000.
 
@@ -343,8 +343,14 @@ class TMC2240:
     def __init__(self, config):
         # Setup mcu communication
         self.fields = tmc.FieldHelper(Fields, SignedFields, FieldFormatters)
-        self.mcu_tmc = tmc2130.MCU_TMC_SPI(config, Registers, self.fields,
-                                           TMC_FREQUENCY)
+        if config.get("uart_pin", None) is not None:
+            # use UART for communication
+            self.mcu_tmc = tmc_uart.MCU_TMC_uart(config, Registers, self.fields,
+                                                 3, TMC_FREQUENCY)
+        else:
+            # Use SPI bus for communication
+            self.mcu_tmc = tmc2130.MCU_TMC_SPI(config, Registers, self.fields,
+                                               TMC_FREQUENCY)
         # Allow virtual pins to be created
         tmc.TMCVirtualPinHelper(config, self.mcu_tmc)
         # Register commands