oops, some boards needed spi prescaler func

firmware/controllers/algo/rusefi_enums.h

@@ -273,6 +273,13 @@ typedef enum __attribute__ ((__packed__)) {
 	UART_DEVICE_4 = 4,
 } uart_device_e;
 
+typedef enum __attribute__ ((__packed__)) {
+	_5MHz,
+	_2_5MHz,
+	_1_25MHz,
+	_150KHz
+} spi_speed_e;
+
 typedef enum __attribute__ ((__packed__)) {
 	SPI_NONE = 0,
 	SPI_DEVICE_1 = 1,

firmware/hw_layer/hardware.cpp

@@ -527,3 +527,25 @@ void initHardware() {
 
 	efiPrintf("initHardware() OK!");
 }
+
+#if HAL_USE_SPI
+// this is F4 implementation but we will keep it here for now for simplicity
+int getSpiPrescaler(spi_speed_e speed, spi_device_e device) {
+	switch (speed) {
+	case _5MHz:
+		return device == SPI_DEVICE_1 ? SPI_BaudRatePrescaler_16 : SPI_BaudRatePrescaler_8;
+	case _2_5MHz:
+		return device == SPI_DEVICE_1 ? SPI_BaudRatePrescaler_32 : SPI_BaudRatePrescaler_16;
+	case _1_25MHz:
+		return device == SPI_DEVICE_1 ? SPI_BaudRatePrescaler_64 : SPI_BaudRatePrescaler_32;
+
+	case _150KHz:
+		// SPI1 does not support 150KHz, it would be 300KHz for SPI1
+		return SPI_BaudRatePrescaler_256;
+	default:
+		// unexpected
+		return 0;
+	}
+}
+
+#endif /* HAL_USE_SPI */

firmware/hw_layer/hardware.h

@@ -31,6 +31,8 @@ void stopHardware();
 //  328.125 KHz 164.06 KHz
 #define SPI_BaudRatePrescaler_256       ((uint16_t)0x0038)
 
+int getSpiPrescaler(spi_speed_e speed, spi_device_e device);
+
 EXTERNC SPIDriver * getSpiDevice(spi_device_e spiDevice);
 void turnOnSpi(spi_device_e device);
 void lockSpi(spi_device_e device);