T4 - put inital calls for check pins and set pins...

Some libraries actually call this.  So define the Hardware data for the one pin for each of the MISO, MOSI, SCK and CS...

So far setting does nothing.

Enough to get Sparkfun Teensyview to build, other than example uses String class which is not included in link phase.

SPI.cpp

 	LPSPI4_CR = LPSPI_CR_RST;
 }
 
+uint8_t SPIClass::pinIsChipSelect(uint8_t pin)
+{
+	return 0;
+}
+
+bool SPIClass::pinIsChipSelect(uint8_t pin1, uint8_t pin2)
+{
+	uint8_t pin1_mask, pin2_mask;
+	if ((pin1_mask = (uint8_t)pinIsChipSelect(pin1)) == 0) return false;
+	if ((pin2_mask = (uint8_t)pinIsChipSelect(pin2)) == 0) return false;
+	//Serial.printf("pinIsChipSelect %d %d %x %x\n\r", pin1, pin2, pin1_mask, pin2_mask);
+	if ((pin1_mask & pin2_mask) != 0) return false;
+	return true;
+}
+
+bool SPIClass::pinIsMOSI(uint8_t pin)
+{
+	for (unsigned int i = 0; i < sizeof(hardware().mosi_pin); i++) {
+		if (pin == hardware().mosi_pin[i]) return true;
+	}
+	return false;
+}
+
+bool SPIClass::pinIsMISO(uint8_t pin)
+{
+	for (unsigned int i = 0; i < sizeof(hardware().miso_pin); i++) {
+		if (pin == hardware().miso_pin[i]) return true;
+	}
+	return false;
+}
+
+bool SPIClass::pinIsSCK(uint8_t pin)
+{
+	for (unsigned int i = 0; i < sizeof(hardware().sck_pin); i++) {
+		if (pin == hardware().sck_pin[i]) return true;
+	}
+	return false;
+}
+
+// setCS() is not intended for use from normal Arduino programs/sketches.
+uint8_t SPIClass::setCS(uint8_t pin)
+{
+	/*
+	for (unsigned int i = 0; i < sizeof(hardware().cs_pin); i++) {
+		if (pin == hardware().cs_pin[i]) {
+			volatile uint32_t *reg = portConfigRegister(pin);
+			*reg = hardware().cs_mux[i];
+			return hardware().cs_mask[i];
+		}
+	} */
+	return 0;
+}
+
+void SPIClass::setMOSI(uint8_t pin)
+{
+	// Currently only one defined so just return...
+}
+
+void SPIClass::setMISO(uint8_t pin)
+{
+	// Currently only one defined so just return...
+}
+
+void SPIClass::setSCK(uint8_t pin)
+{
+	// Currently only one defined so just return...
+}
+
+
+
 
 const SPIClass::SPI_Hardware_t SPIClass::lpspi4_hardware = {
 	CCM_CCGR1,
-	CCM_CCGR1_LPSPI4(CCM_CCGR_ON)
+	12, 
+	3 | 0x10,
+	11,
+	3 | 0x10,
+	13,
+	3 | 0x10,
+	10,
+	3 | 0x10,
 };
 SPIClass SPI(0, (uintptr_t)&SPIClass::lpspi4_hardware);
 

SPI.h

 	friend class SPIClass;
 };
 
-
-
 class SPIClass { // Teensy 4
 public:
+	static const uint8_t CNT_MISO_PINS = 1;
+	static const uint8_t CNT_MOSI_PINS = 1;
+	static const uint8_t CNT_SCK_PINS = 1;
+	static const uint8_t CNT_CS_PINS = 1;
 	typedef struct {
 		volatile uint32_t &clock_gate_register;
 		uint32_t clock_gate_mask;
+		uint8_t  miso_pin[CNT_MISO_PINS];
+		uint32_t  miso_mux[CNT_MISO_PINS];
+		uint8_t  mosi_pin[CNT_MOSI_PINS];
+		uint32_t  mosi_mux[CNT_MOSI_PINS];
+		uint8_t  sck_pin[CNT_SCK_PINS];
+		uint32_t  sck_mux[CNT_SCK_PINS];
+		uint8_t  cs_pin[CNT_CS_PINS];
+		uint32_t  cs_mux[CNT_CS_PINS];
 	} SPI_Hardware_t;
 	static const SPI_Hardware_t lpspi4_hardware;
 
 		//return port().POPR;
 	}
 	uint16_t transfer16(uint16_t data) {
-		transfer(data >> 8);
-		transfer(data & 255);
+		uint16_t ret_val = transfer(data >> 8);
+		ret_val = (ret_val << 8) | transfer(data & 255);
 		//port().SR = SPI_SR_TCF;
 		//port().PUSHR = data | SPI_PUSHR_CTAS(1);
 		//while (!(port().SR & SPI_SR_TCF)) ; // wait
 		//return port().POPR;
+		return ret_val;
 	}
 
 	void inline transfer(void *buf, size_t count) {transfer(buf, buf, count);}