Add support for reading multiple bytes in one call

- Fixes #49

Author: bparks13

Source/Devices/PolledBno055.cpp

@@ -209,14 +209,13 @@ void PolledBno055::addSourceBuffers(OwnedArray<DataBuffer>& sourceBuffers)
 
 int16_t PolledBno055::readInt16(uint32_t startAddress)
 {
-	oni_reg_val_t byte1 = 0, byte2 = 0;
+	uint32_t value = 0;
+	int rc = ReadWord(startAddress, 2, &value);
 
-	int rc = ReadByte(startAddress, &byte1);
-	if (rc != ONI_ESUCCESS) return 0;
-	rc = ReadByte(startAddress + 1, &byte2);
-	if (rc != ONI_ESUCCESS) return 0;
+	if (rc != ONI_ESUCCESS)
+		return 0;
 
-	return (static_cast<int16_t>(byte2) << 8) | byte1;
+	return static_cast<int16_t>(value);
 }
 
 void PolledBno055::hiResTimerCallback()

Source/I2CRegisterContext.cpp

@@ -40,8 +40,20 @@ int I2CRegisterContext::WriteByte(uint32_t address, uint32_t value, bool sixteen
 
 int I2CRegisterContext::ReadByte(uint32_t address, oni_reg_val_t* value, bool sixteenBitAddress)
 {
+	return ReadWord(address, 1, value, sixteenBitAddress);
+}
+
+int I2CRegisterContext::ReadWord(uint32_t address, uint32_t numBytes, uint32_t* value, bool sixteenBitAddress)
+{
+	if (numBytes < 1 || numBytes > 4)
+	{
+		LOGE("Invalid number of bytes requested when reading a word.");
+		return 1;
+	}
+
 	uint32_t registerAddress = (address << 7) | (i2cAddress & 0x7F);
 	registerAddress |= sixteenBitAddress ? 0x80000000 : 0;
+	registerAddress |= (numBytes - 1) << 28;
 
 	return i2cContext->readRegister(deviceIndex, registerAddress, value);
 }

Source/I2CRegisterContext.h

@@ -39,8 +39,12 @@ namespace OnixSourcePlugin
 
 		int WriteByte(uint32_t address, uint32_t value, bool sixteenBitAddress = false);
 
+		int WriteWord(uint32_t address, uint32_t value, uint32_t numBytes, bool sixteenBitAddress = false);
+
 		int ReadByte(uint32_t address, oni_reg_val_t* value, bool sixteenBitAddress = false);
 
+		int ReadWord(uint32_t address, uint32_t numBytes, uint32_t* value, bool sixteenBitAddress = false);
+
 		int set933I2cRate(double);
 
 	protected: