Fix SPI

Author: giulcioffi

libraries/SPI/SPI.cpp

@@ -26,29 +26,7 @@
 #define SPI_IMODE_EXTINT 1
 #define SPI_IMODE_GLOBAL 2
 
-//const SPISettings DEFAULT_SPI_SETTINGS = SPISettings();
-
-static inline SercomDataOrder getBitOrder(SPISettings& settings) {
-  return (settings.getBitOrder() == MSBFIRST ? MSB_FIRST : LSB_FIRST);
-}
-
-static inline SercomSpiClockMode getDataMode(SPISettings& settings) {
-    switch (settings.getDataMode())
-    {
-      case SPI_MODE0:
-        return SERCOM_SPI_MODE_0; break;
-      case SPI_MODE1:
-        return SERCOM_SPI_MODE_1; break;
-      case SPI_MODE2:
-        return SERCOM_SPI_MODE_2; break;
-      case SPI_MODE3:
-        return SERCOM_SPI_MODE_3; break;
-      default:
-        return SERCOM_SPI_MODE_0; break;
-    }
-}
-
-SPIClass::SPIClass(SERCOM *p_sercom, uint8_t uc_pinMISO, uint8_t uc_pinSCK, uint8_t uc_pinMOSI, SercomSpiTXPad PadTx, SercomRXPad PadRx)
+SPIClass::SPIClass(SERCOM *p_sercom, uint8_t uc_pinMISO, uint8_t uc_pinSCK, uint8_t uc_pinMOSI, SercomSpiTXPad PadTx, SercomRXPad PadRx) : settings(SPISettings(0, MSBFIRST, SPI_MODE0))
 {
   initialized = false;
   assert(p_sercom != NULL);
@@ -86,14 +64,14 @@ void SPIClass::init()
   initialized = true;
 }
 
-void SPIClass::config(SPISettings settings)
+void SPIClass::config(SPISettingsSAMD settings)
 {
   if (this->settings != settings) {
     this->settings = settings;
     _p_sercom->disableSPI();
 
-  _p_sercom->initSPI(_padTx, _padRx, SPI_CHAR_SIZE_8_BITS, getBitOrder(settings));
-  _p_sercom->initSPIClock(getDataMode(settings), settings.getClockFreq());
+  _p_sercom->initSPI(_padTx, _padRx, SPI_CHAR_SIZE_8_BITS, settings.bitOrder);
+  _p_sercom->initSPIClock(settings.dataMode, settings.clockFreq);
 
     _p_sercom->enableSPI();
   }
@@ -155,7 +133,7 @@ void SPIClass::notUsingInterrupt(int interruptNumber)
     interrupts();
 }
 
-void SPIClass::beginTransaction(SPISettings settings)
+void SPIClass::beginTransaction(SPISettingsSAMD settings)
 {
   if (interruptMode != SPI_IMODE_NONE)
   {

libraries/SPI/SPI.h

@@ -46,6 +46,53 @@
   #define SPI_MIN_CLOCK_DIVIDER (uint8_t)(1 + ((F_CPU - 1) / 12000000))
 #endif
 
+class SPISettingsSAMD : public arduino::SPISettings {
+  public:
+  SPISettingsSAMD(uint32_t clock, BitOrder bitOrder, uint8_t dataMode) {
+    if (__builtin_constant_p(clock)) {
+      init_AlwaysInline(clock, bitOrder, dataMode);
+    } else {
+      init_MightInline(clock, bitOrder, dataMode);
+    }
+  }
+
+  // Default speed set to 4MHz, SPI mode set to MODE 0 and Bit order set to MSB first.
+  SPISettingsSAMD() { init_AlwaysInline(4000000, MSBFIRST, SPI_MODE0); }
+
+  SPISettingsSAMD(SPISettings& x) { SPISettingsSAMD(x.getClockFreq(), x.getBitOrder(), x.getDataMode()); }
+
+  private:
+  void init_MightInline(uint32_t clock, BitOrder bitOrder, uint8_t dataMode) {
+    init_AlwaysInline(clock, bitOrder, dataMode);
+  }
+
+  void init_AlwaysInline(uint32_t clock, BitOrder bitOrder, uint8_t dataMode) __attribute__((__always_inline__)) {
+    this->clockFreq = (clock >= (F_CPU / SPI_MIN_CLOCK_DIVIDER) ? F_CPU / SPI_MIN_CLOCK_DIVIDER : clock);
+
+    this->bitOrder = (bitOrder == MSBFIRST ? MSB_FIRST : LSB_FIRST);
+
+    switch (dataMode)
+    {
+      case SPI_MODE0:
+        this->dataMode = SERCOM_SPI_MODE_0; break;
+      case SPI_MODE1:
+        this->dataMode = SERCOM_SPI_MODE_1; break;
+      case SPI_MODE2:
+        this->dataMode = SERCOM_SPI_MODE_2; break;
+      case SPI_MODE3:
+        this->dataMode = SERCOM_SPI_MODE_3; break;
+      default:
+        this->dataMode = SERCOM_SPI_MODE_0; break;
+    }
+  }
+
+  uint32_t clockFreq;
+  SercomSpiClockMode dataMode;
+  SercomDataOrder bitOrder;
+
+  friend class SPIClassSAMD;
+};
+
 class SPIClassSAMD : public arduino::HardwareSPI {
   public:
   SPIClassSAMD(SERCOM *p_sercom, uint8_t uc_pinMISO, uint8_t uc_pinSCK, uint8_t uc_pinMOSI, SercomSpiTXPad, SercomRXPad);
@@ -57,7 +104,10 @@ class SPIClassSAMD : public arduino::HardwareSPI {
   // Transaction Functions
   void usingInterrupt(int interruptNumber);
   void notUsingInterrupt(int interruptNumber);
-  void beginTransaction(SPISettings settings);
+  void beginTransaction(SPISettingsSAMD settings);
+  void beginTransaction(SPISettings settings) {
+    beginTransaction(SPISettingsSAMD(settings));
+  }
   void endTransaction(void);
 
   // SPI Configuration methods
@@ -73,7 +123,10 @@ class SPIClassSAMD : public arduino::HardwareSPI {
 
   private:
   void init();
-  void config(SPISettings settings);
+  void config(SPISettingsSAMD settings);
+  void config(SPISettings settings) {
+    config(SPISettingsSAMD(settings));
+  }
 
   SERCOM *_p_sercom;
   uint8_t _uc_pinMiso;