+/**
+ * I2C Backends.
+ * \{
+ */
+#define I2C_BACKEND_BUILTIN 0 ///< Uses cpu builtin i2c driver
+#define I2C_BACKEND_BITBANG 1 ///< Uses emulated bitbang driver
+/*\}*/
+
+void i2c_builtin_init(void);
+bool i2c_builtin_start_w(uint8_t id);
+bool i2c_builtin_start_r(uint8_t id);
+void i2c_builtin_stop(void);
+bool i2c_builtin_put(uint8_t _data);
+int i2c_builtin_get(bool ack);
+
+void i2c_bitbang_init(void);
+bool i2c_bitbang_start_w(uint8_t id);
+bool i2c_bitbang_start_r(uint8_t id);
+void i2c_bitbang_stop(void);
+bool i2c_bitbang_put(uint8_t _data);
+int i2c_bitbang_get(bool ack);
+
+
+#if CONFIG_I2C_BACKEND == I2C_BACKEND_BUILTIN
+ #define i2c_init i2c_builtin_init
+ #define i2c_start_w i2c_builtin_start_w
+ #define i2c_start_r i2c_builtin_start_r
+ #define i2c_stop i2c_builtin_stop
+ #define i2c_put i2c_builtin_put
+ #define i2c_get i2c_builtin_get
+#elif CONFIG_I2C_BACKEND == I2C_BACKEND_BITBANG
+ #define i2c_init i2c_bitbang_init
+ #define i2c_start_w i2c_bitbang_start_w
+ #define i2c_start_r i2c_bitbang_start_r
+ #define i2c_stop i2c_bitbang_stop
+ #define i2c_put i2c_bitbang_put
+ #define i2c_get i2c_bitbang_get
+#else
+ #error Unsupported i2c backend.
+#endif
+