[avr] Added SPI.notUsingInterrupt() (Andrew Kroll)

Author: cmaglie

hardware/arduino/avr/libraries/SPI/SPI.cpp

@@ -141,3 +141,44 @@ void SPIClass::usingInterrupt(uint8_t interruptNumber)
   SREG = sreg;
 }
 
+void SPIClass::notUsingInterrupt(uint8_t interruptNumber)
+{
+  uint8_t mask = 0;
+  uint8_t sreg = SREG;
+  noInterrupts(); // Protect from a scheduler and prevent transactionBegin
+  switch (interruptNumber) {
+  #ifdef SPI_INT0_MASK
+  case 0: mask = SPI_INT0_MASK; break;
+  #endif
+  #ifdef SPI_INT1_MASK
+  case 1: mask = SPI_INT1_MASK; break;
+  #endif
+  #ifdef SPI_INT2_MASK
+  case 2: mask = SPI_INT2_MASK; break;
+  #endif
+  #ifdef SPI_INT3_MASK
+  case 3: mask = SPI_INT3_MASK; break;
+  #endif
+  #ifdef SPI_INT4_MASK
+  case 4: mask = SPI_INT4_MASK; break;
+  #endif
+  #ifdef SPI_INT5_MASK
+  case 5: mask = SPI_INT5_MASK; break;
+  #endif
+  #ifdef SPI_INT6_MASK
+  case 6: mask = SPI_INT6_MASK; break;
+  #endif
+  #ifdef SPI_INT7_MASK
+  case 7: mask = SPI_INT7_MASK; break;
+  #endif
+  default:
+    if (interruptMask) {
+      modeFlags.interruptMode = 1;
+    } else {
+      modeFlags.interruptMode = 0;
+    }
+    break;
+  }
+  interruptMask &= ~mask;
+  SREG = sreg;
+}

hardware/arduino/avr/libraries/SPI/SPI.h

@@ -20,6 +20,9 @@
 // usingInterrupt(), and SPISetting(clock, bitOrder, dataMode)
 #define SPI_HAS_TRANSACTION 1
 
+// SPI_HAS_NOTUSINGINTERRUPT means that SPI has notUsingInterrup() method
+#define SPI_HAS_NOTUSINGINTERRUPT 1
+
 // SPI_ATOMIC_VERSION means that SPI has atomicity fixes and what version.
 // This way when there is a bug fix you can check this define to alert users
 // of your code if it uses better version of this library.
@@ -169,6 +172,8 @@ class SPIClass {
   // with attachInterrupt.  If SPI is used from a different interrupt
   // (eg, a timer), interruptNumber should be 255.
   static void usingInterrupt(uint8_t interruptNumber);
+  // And this does the opposite.
+  static void notUsingInterrupt(uint8_t interruptNumber);
 
   // Before using SPI.transfer() or asserting chip select pins,
   // this function is used to gain exclusive access to the SPI bus