Robin FSMC / SPI pins

Marlin/src/HAL/HAL_STM32F1/HAL_spi_STM32F1.cpp

  * @details Only configures SS pin since libmaple creates and initialize the SPI object
  */
 void spiBegin() {
-  #if !PIN_EXISTS(SS)
-    #error "SS_PIN not defined!"
+  #if PIN_EXISTS(SS)
+    OUT_WRITE(SS_PIN, HIGH);
   #endif
-  OUT_WRITE(SS_PIN, HIGH);
 }
 
 /**

Marlin/src/pins/stm32/pins_MKS_ROBIN_MINI.h

  * to let the bootloader init the screen.
  */
 #if ENABLED(FSMC_GRAPHICAL_TFT)
+  #define FSMC_CS_PIN      PD7    // NE4
+  #define FSMC_RS_PIN      PD11   // A0
+
   #define LCD_RESET_PIN    PF6
   #define NO_LCD_REINIT           // Suppress LCD re-initialization
 
 
   #if ENABLED(TOUCH_BUTTONS)
     #define BTN_ENC        PB3    // Not connected. TODO: Replace this hack to enable button code
-    #define FSMC_CS_PIN    PD7    // NE4
-    #define FSMC_RS_PIN    PD11   // A0
     #define TOUCH_CS_PIN   PC2
   #endif
 #endif

Marlin/src/pins/stm32/pins_MKS_ROBIN_NANO.h

  * to let the bootloader init the screen.
  */
 #if ENABLED(FSMC_GRAPHICAL_TFT)
+  #define FSMC_CS_PIN        PD7    // NE4
+  #define FSMC_RS_PIN        PD11   // A0
+
   #define LCD_RESET_PIN      PF6
   #define NO_LCD_REINIT             // Suppress LCD re-initialization
 
 
   #if ENABLED(TOUCH_BUTTONS)
     #define BTN_ENC          PC13   // Not connected. TODO: Replace this hack to enable button code
-    #define FSMC_CS_PIN      PD7    // NE4
-    #define FSMC_RS_PIN      PD11   // A0
     #define TOUCH_CS_PIN     PA7
   #endif
 #endif