diff --git a/src/maa.i b/src/maa.i
index e053282..60ac1ee 100644
--- a/src/maa.i
+++ b/src/maa.i
@@ -17,6 +17,31 @@ const char * maa_get_version();
 
 #### GPIO ####
 
+/**
+ * GPIO Output modes
+ */
+typedef enum {
+    MAA_GPIO_STRONG     = 0, /**< Default. Strong high and low */
+    MAA_GPIO_PULLUP     = 1, /**< Resistive High */
+    MAA_GPIO_PULLDOWN   = 2, /**< Resistive Low */
+    MAA_GPIO_HIZ        = 3  /**< High Z State */
+} gpio_mode_t;
+
+/**
+ * GPIO Direction options.
+ */
+typedef enum {
+    MAA_GPIO_OUT    = 0, /**< Output. A Mode can also be set */
+    MAA_GPIO_IN     = 1  /**< Input. */
+} gpio_dir_t;
+
+typedef enum {
+    MAA_GPIO_EDGE_NONE    = 0, /**< No interrupt on GPIO */
+    MAA_GPIO_EDGE_BOTH    = 1, /**< Interupt on rising & falling */
+    MAA_GPIO_EDGE_RISING  = 2, /**< Interupt on rising only */
+    MAA_GPIO_EDGE_FALLING = 3  /**< Interupt on falling only */
+} gpio_edge_t;
+
 %include "gpio.hpp"
 
 #### i2c ####