diff --git a/include/drivers/arm/tzc400.h b/include/drivers/arm/tzc400.h
index 7eaafd2..7ac82ae 100644
--- a/include/drivers/arm/tzc400.h
+++ b/include/drivers/arm/tzc400.h
@@ -165,23 +165,23 @@
  *  TZC_ACTION_ERR_INT - Raise interrupt, raise exception -> sync
  *                       external data abort
  */
-enum tzc_action {
+typedef enum {
 	TZC_ACTION_NONE = 0,
 	TZC_ACTION_ERR = 1,
 	TZC_ACTION_INT = 2,
 	TZC_ACTION_ERR_INT = (TZC_ACTION_ERR | TZC_ACTION_INT)
-};
+} tzc_action_t;
 
 /*
  * Controls secure access to a region. If not enabled secure access is not
  * allowed to region.
  */
-enum tzc_region_attributes {
+typedef enum {
 	TZC_REGION_S_NONE = 0,
 	TZC_REGION_S_RD = 1,
 	TZC_REGION_S_WR = 2,
 	TZC_REGION_S_RDWR = (TZC_REGION_S_RD | TZC_REGION_S_WR)
-};
+} tzc_region_attributes_t;
 
 /*
  * Implementation defined values used to validate inputs later.
@@ -189,22 +189,21 @@
  * Regions : max of 9 ; 0 to 8
  * Address width : Values between 32 to 64
  */
-struct tzc_instance {
+typedef struct tzc_instance {
 	uint64_t base;
 	uint32_t aid_width;
 	uint8_t addr_width;
 	uint8_t num_filters;
 	uint8_t num_regions;
-};
+} tzc_instance_t ;
 
-void tzc_init(struct tzc_instance *controller);
-void tzc_configure_region(const struct tzc_instance *controller, uint32_t filters,
+void tzc_init(tzc_instance_t *controller);
+void tzc_configure_region(const tzc_instance_t *controller, uint32_t filters,
 	uint8_t region, uint64_t region_base, uint64_t region_top,
-	enum tzc_region_attributes sec_attr, uint32_t ns_device_access);
-void tzc_enable_filters(const struct tzc_instance *controller);
-void tzc_disable_filters(const struct tzc_instance *controller);
-void tzc_set_action(const struct tzc_instance *controller,
-	enum tzc_action action);
+	tzc_region_attributes_t sec_attr, uint32_t ns_device_access);
+void tzc_enable_filters(const tzc_instance_t *controller);
+void tzc_disable_filters(const tzc_instance_t *controller);
+void tzc_set_action(const tzc_instance_t *controller, tzc_action_t action);
 
 #endif /*__ASSEMBLY__*/
 
diff --git a/include/drivers/io_driver.h b/include/drivers/io_driver.h
index 5e3d132..cade5e7 100644
--- a/include/drivers/io_driver.h
+++ b/include/drivers/io_driver.h
@@ -36,58 +36,58 @@
 
 /* Generic IO entity structure,representing an accessible IO construct on the
  * device, such as a file */
-struct io_entity {
+typedef struct io_entity {
 	io_dev_handle dev_handle;
 	uintptr_t info;
-};
+} io_entity_t;
 
 
 /* Device info structure, providing device-specific functions and a means of
  * adding driver-specific state */
-struct io_dev_info {
+typedef struct io_dev_info {
 	struct io_dev_funcs *funcs;
 	uintptr_t info;
-};
+} io_dev_info_t;
 
 
 /* Structure used to create a connection to a type of device */
-struct io_dev_connector {
+typedef struct io_dev_connector {
 	/* dev_open opens a connection to a particular device driver */
-	int (*dev_open)(void *spec, struct io_dev_info **dev_info);
-};
+	int (*dev_open)(void *spec, io_dev_info_t **dev_info);
+} io_dev_connector_t;
 
 
 /* Structure to hold device driver function pointers */
-struct io_dev_funcs {
-	io_type (*type)(void);
-	int (*open)(struct io_dev_info *dev_info, const void *spec,
-			struct io_entity *entity);
-	int (*seek)(struct io_entity *entity, int mode, ssize_t offset);
-	int (*size)(struct io_entity *entity, size_t *length);
-	int (*read)(struct io_entity *entity, void *buffer, size_t length,
+typedef struct io_dev_funcs {
+	io_type_t (*type)(void);
+	int (*open)(io_dev_info_t *dev_info, const void *spec,
+			io_entity_t *entity);
+	int (*seek)(io_entity_t *entity, int mode, ssize_t offset);
+	int (*size)(io_entity_t *entity, size_t *length);
+	int (*read)(io_entity_t *entity, void *buffer, size_t length,
 			size_t *length_read);
-	int (*write)(struct io_entity *entity, const void *buffer,
+	int (*write)(io_entity_t *entity, const void *buffer,
 			size_t length, size_t *length_written);
-	int (*close)(struct io_entity *entity);
-	int (*dev_init)(struct io_dev_info *dev_info, const void *init_params);
-	int (*dev_close)(struct io_dev_info *dev_info);
-};
+	int (*close)(io_entity_t *entity);
+	int (*dev_init)(io_dev_info_t *dev_info, const void *init_params);
+	int (*dev_close)(io_dev_info_t *dev_info);
+} io_dev_funcs_t;
 
 
 /* IO platform data - used to track devices registered for a specific
  * platform */
-struct io_plat_data {
-	struct io_dev_info *devices[MAX_IO_DEVICES];
+typedef struct io_plat_data {
+	io_dev_info_t *devices[MAX_IO_DEVICES];
 	unsigned int dev_count;
-};
+} io_plat_data_t;
 
 
 /* Operations intended to be performed during platform initialisation */
 
 /* Initialise the IO layer */
-void io_init(struct io_plat_data *data);
+void io_init(io_plat_data_t *data);
 
 /* Register a device driver */
-int io_register_device(struct io_dev_info *dev_info);
+int io_register_device(io_dev_info_t *dev_info);
 
 #endif  /* __IO_DRIVER_H__ */