TMC SPI Endstops and Improved Sensorless Homing (#14044)

Marlin/src/Marlin.cpp

@@ -659,6 +659,13 @@ void idle(
     bool no_stepper_sleep/*=false*/
   #endif
 ) {
+
+  #if ENABLED(SPI_ENDSTOPS)
+    if (endstops.tmc_spi_homing.any && ELAPSED(millis(), sg_guard_period))
+      for (uint8_t i = 4; i--;) // Read SGT 4 times per idle loop
+        if (endstops.tmc_spi_homing_check()) break;
+  #endif
+
   #if ENABLED(MAX7219_DEBUG)
     max7219.idle_tasks();
   #endif