Merge pull request #93 from jvaque/master

Minor refactoring of some functions

Author: caternuson

src/Adafruit_MCP23XXX.cpp

@@ -225,7 +225,6 @@ void Adafruit_MCP23XXX::clearInterrupts() {
 */
 /**************************************************************************/
 uint8_t Adafruit_MCP23XXX::getLastInterruptPin() {
-  uint8_t intpin = MCP23XXX_INT_ERR;
   uint8_t intf;
 
   // Port A
@@ -234,25 +233,23 @@ uint8_t Adafruit_MCP23XXX::getLastInterruptPin() {
   INTFA.read(&intf);
   for (uint8_t pin = 0; pin < 8; pin++) {
     if (intf & (1 << pin)) {
-      intpin = pin;
-      break;
+      return pin;
     }
   }
 
-  // Port B and still not found?
-  if ((pinCount > 8) && (intpin == MCP23XXX_INT_ERR)) {
+  // Port B ?
+  if (pinCount > 8) {
     Adafruit_BusIO_Register INTFB(i2c_dev, spi_dev, MCP23XXX_SPIREG,
                                   getRegister(MCP23XXX_INTF, 1));
     INTFB.read(&intf);
     for (uint8_t pin = 0; pin < 8; pin++) {
       if (intf & (1 << pin)) {
-        intpin = pin + 8;
-        break;
+        return pin + 8;
       }
     }
   }
 
-  return intpin;
+  return MCP23XXX_INT_ERR;
 }
 
 /**************************************************************************/
@@ -295,10 +292,8 @@ uint16_t Adafruit_MCP23XXX::getRegister(uint8_t baseAddress, uint8_t port) {
   uint16_t reg = baseAddress;
   // MCP23x17 BANK=0
   if (pinCount > 8) {
-    reg *= 2;
-    // Port B
-    if (port)
-      reg++;
+    reg <<= 1;
+    reg |= port;
   }
   // for SPI, add opcode as high byte
   return (spi_dev) ? (0x4000 | (hw_addr << 9) | reg) : reg;

src/Adafruit_MCP23XXX.h

@@ -64,10 +64,10 @@ class Adafruit_MCP23XXX {
   uint16_t getCapturedInterrupt();
 
 protected:
-  Adafruit_I2CDevice *i2c_dev = NULL; ///< Pointer to I2C bus interface
-  Adafruit_SPIDevice *spi_dev = NULL; ///< Pointer to SPI bus interface
-  uint8_t pinCount;                   ///< Total number of GPIO pins
-  uint8_t hw_addr;                    ///< HW address matching A2/A1/A0 pins
+  Adafruit_I2CDevice *i2c_dev = nullptr; ///< Pointer to I2C bus interface
+  Adafruit_SPIDevice *spi_dev = nullptr; ///< Pointer to SPI bus interface
+  uint8_t pinCount;                      ///< Total number of GPIO pins
+  uint8_t hw_addr;                       ///< HW address matching A2/A1/A0 pins
   uint16_t getRegister(uint8_t baseAddress, uint8_t port = 0);
 
 private: