allow a register to be i2c or spi

Adafruit_BusIO_Register.cpp

@@ -22,6 +22,19 @@ Adafruit_BusIO_Register::Adafruit_BusIO_Register(Adafruit_SPIDevice *spidevice,
   _width = width;
 }
 
+Adafruit_BusIO_Register::Adafruit_BusIO_Register(Adafruit_I2CDevice *i2cdevice, Adafruit_SPIDevice *spidevice, 
+						 uint16_t reg_addr, Adafruit_BusIO_SPIRegType type,
+						 uint8_t width, uint8_t bitorder, uint8_t address_width) {
+  _spidevice = spidevice;
+  _i2cdevice = i2cdevice;
+  _spiregtype = type;
+  _addrwidth = address_width;
+  _address = reg_addr;
+  _bitorder = bitorder;
+  _width = width;
+}
+
+
 bool Adafruit_BusIO_Register::write(uint8_t *buffer, uint8_t len) {
 
   uint8_t addrbuffer[2] = {(uint8_t)(_address & 0xFF), (uint8_t)(_address>>8)};

Adafruit_BusIO_Register.h

@@ -19,6 +19,14 @@ class Adafruit_BusIO_Register {
 			  Adafruit_BusIO_SPIRegType type,
 			  uint8_t width=1, uint8_t bitorder=LSBFIRST,
 			  uint8_t address_width=1); 
+
+  Adafruit_BusIO_Register(Adafruit_I2CDevice *i2cdevice,
+			  Adafruit_SPIDevice *spidevice, 
+			  uint16_t reg_addr, 
+			  Adafruit_BusIO_SPIRegType type,
+			  uint8_t width=1, uint8_t bitorder=LSBFIRST,
+			  uint8_t address_width=1); 
+
   bool read(uint8_t *buffer, uint8_t len);
   bool read(uint8_t *value);
   bool read(uint16_t *value);

examples/i2corspi_register/i2corspi_register.ino

@@ -0,0 +1,38 @@
+#include <Adafruit_BusIO_Register.h>
+
+// Define which interface to use by setting the unused interface to NULL!
+
+#define SPIDEVICE_CS 10
+Adafruit_SPIDevice *spi_dev = NULL; // new Adafruit_SPIDevice(SPIDEVICE_CS);
+
+#define I2C_ADDRESS 0x5D
+Adafruit_I2CDevice *i2c_dev = new Adafruit_I2CDevice(I2C_ADDRESS);
+
+void setup() {
+  while (!Serial) { delay(10); }
+  Serial.begin(115200);
+  Serial.println("I2C or SPI device register test");
+
+  if (spi_dev && !spi_dev->begin()) {
+    Serial.println("Could not initialize SPI device");
+  }
+
+  if (i2c_dev) {
+    if (i2c_dev->begin()) {
+      Serial.print("Device found on I2C address 0x");
+      Serial.println(i2c_dev->address(), HEX);
+    } else {
+      Serial.print("Did not find I2C device at 0x");
+      Serial.println(i2c_dev->address(), HEX);
+    }
+  }
+
+  Adafruit_BusIO_Register id_reg = Adafruit_BusIO_Register(i2c_dev, spi_dev, 0x0F, ADDRBIT8_HIGH_TOREAD);
+  uint8_t id;
+  id_reg.read(&id);
+  Serial.print("ID register = 0x"); Serial.println(id, HEX);
+}
+
+void loop() {
+  
+}