Minor SPI fixes, systick_callback for STM32F1 HAL compatibility (#19565)

Marlin/src/HAL/STM32/HAL.cpp

 void HAL_init() {
   FastIO_init();
 
-  #if ENABLED(SDSUPPORT) && DISABLED(SDIO_SUPPORT)
+  #if ENABLED(SDSUPPORT) && DISABLED(SDIO_SUPPORT) && (defined(SDSS) && SDSS != -1)
     OUT_WRITE(SDSS, HIGH); // Try to set SDSS inactive before any other SPI users start up
   #endif
 
 
 // TODO: Make sure this doesn't cause any delay
 void HAL_adc_start_conversion(const uint8_t adc_pin) { HAL_adc_result = analogRead(adc_pin); }
-
 uint16_t HAL_adc_get_result() { return HAL_adc_result; }
 
+// Reset the system (to initiate a firmware flash)
 void flashFirmware(const int16_t) { NVIC_SystemReset(); }
 
+// Maple Compatibility
+systickCallback_t systick_user_callback;
+void systick_attach_callback(systickCallback_t cb) { systick_user_callback = cb; }
+void HAL_SYSTICK_Callback() { if (systick_user_callback) systick_user_callback(); }
+
 #endif // ARDUINO_ARCH_STM32 && !STM32GENERIC

Marlin/src/HAL/STM32/HAL.h

 
 #define PLATFORM_M997_SUPPORT
 void flashFirmware(const int16_t);
+
+// Maple Compatibility
+typedef void (*systickCallback_t)(void);
+void systick_attach_callback(systickCallback_t cb);
+void HAL_SYSTICK_Callback();

Marlin/src/HAL/STM32/HAL_SPI.cpp

    * @details Only configures SS pin since stm32duino 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);
   }
 
   // Configure SPI for specified SPI speed
    * @details
    */
   uint8_t spiRec() {
-    SPI.beginTransaction(spiConfig);
     uint8_t returnByte = SPI.transfer(0xFF);
-    SPI.endTransaction();
     return returnByte;
   }
 
   void spiRead(uint8_t* buf, uint16_t nbyte) {
     if (nbyte == 0) return;
     memset(buf, 0xFF, nbyte);
-    SPI.beginTransaction(spiConfig);
     SPI.transfer(buf, nbyte);
-    SPI.endTransaction();
   }
 
   /**
    * @details
    */
   void spiSend(uint8_t b) {
-    SPI.beginTransaction(spiConfig);
     SPI.transfer(b);
-    SPI.endTransaction();
   }
 
   /**
    */
   void spiSendBlock(uint8_t token, const uint8_t* buf) {
     uint8_t rxBuf[512];
-    SPI.beginTransaction(spiConfig);
     SPI.transfer(token);
     SPI.transfer((uint8_t*)buf, &rxBuf, 512);
-    SPI.endTransaction();
   }
 
 #endif // SOFTWARE_SPI