diff --git a/drivers/usb/gadget/core.c b/drivers/usb/gadget/core.c
index 3781d25fd6..888f0cfea6 100644
--- a/drivers/usb/gadget/core.c
+++ b/drivers/usb/gadget/core.c
@@ -36,7 +36,7 @@ extern struct usb_function_driver ep0_driver;
 int registered_functions;
 int registered_devices;
 
-char *usbd_device_events[] = {
+__maybe_unused static char *usbd_device_events[] = {
 	"DEVICE_UNKNOWN",
 	"DEVICE_INIT",
 	"DEVICE_CREATE",
@@ -56,52 +56,15 @@ char *usbd_device_events[] = {
 	"DEVICE_FUNCTION_PRIVATE",
 };
 
-char *usbd_device_states[] = {
-	"STATE_INIT",
-	"STATE_CREATED",
-	"STATE_ATTACHED",
-	"STATE_POWERED",
-	"STATE_DEFAULT",
-	"STATE_ADDRESSED",
-	"STATE_CONFIGURED",
-	"STATE_UNKNOWN",
-};
-
-char *usbd_device_requests[] = {
-	"GET STATUS",		/* 0 */
-	"CLEAR FEATURE",	/* 1 */
-	"RESERVED",		/* 2 */
-	"SET FEATURE",		/* 3 */
-	"RESERVED",		/* 4 */
-	"SET ADDRESS",		/* 5 */
-	"GET DESCRIPTOR",	/* 6 */
-	"SET DESCRIPTOR",	/* 7 */
-	"GET CONFIGURATION",	/* 8 */
-	"SET CONFIGURATION",	/* 9 */
-	"GET INTERFACE",	/* 10 */
-	"SET INTERFACE",	/* 11 */
-	"SYNC FRAME",		/* 12 */
-};
-
-char *usbd_device_descriptors[] = {
-	"UNKNOWN",		/* 0 */
-	"DEVICE",		/* 1 */
-	"CONFIG",		/* 2 */
-	"STRING",		/* 3 */
-	"INTERFACE",		/* 4 */
-	"ENDPOINT",		/* 5 */
-	"DEVICE QUALIFIER",	/* 6 */
-	"OTHER SPEED",		/* 7 */
-	"INTERFACE POWER",	/* 8 */
-};
-
-char *usbd_device_status[] = {
+__maybe_unused static char *usbd_device_status[] = {
 	"USBD_OPENING",
 	"USBD_OK",
 	"USBD_SUSPENDED",
 	"USBD_CLOSING",
 };
 
+#define USBD_DEVICE_STATUS(x) (((unsigned int)x <= USBD_CLOSING) ? usbd_device_status[x] : "UNKNOWN")
+
 
 /* Descriptor support functions ************************************************************** */
 
diff --git a/drivers/usb/gadget/ep0.c b/drivers/usb/gadget/ep0.c
index 6fabee24ce..457679f0a4 100644
--- a/drivers/usb/gadget/ep0.c
+++ b/drivers/usb/gadget/ep0.c
@@ -46,6 +46,52 @@
 #define dbg_ep0(lvl,fmt,args...)
 #endif
 
+__maybe_unused static char *usbd_device_descriptors[] = {
+	"UNKNOWN",		/* 0 */
+	"DEVICE",		/* 1 */
+	"CONFIG",		/* 2 */
+	"STRING",		/* 3 */
+	"INTERFACE",		/* 4 */
+	"ENDPOINT",		/* 5 */
+	"DEVICE QUALIFIER",	/* 6 */
+	"OTHER SPEED",		/* 7 */
+	"INTERFACE POWER",	/* 8 */
+};
+
+#define USBD_DEVICE_DESCRIPTORS(x) (((unsigned int)x <= USB_DESCRIPTOR_TYPE_INTERFACE_POWER) ? \
+		usbd_device_descriptors[x] : "UNKNOWN")
+
+__maybe_unused static char *usbd_device_states[] = {
+	"STATE_INIT",
+	"STATE_CREATED",
+	"STATE_ATTACHED",
+	"STATE_POWERED",
+	"STATE_DEFAULT",
+	"STATE_ADDRESSED",
+	"STATE_CONFIGURED",
+	"STATE_UNKNOWN",
+};
+
+#define USBD_DEVICE_STATE(x) (((unsigned int)x <= STATE_UNKNOWN) ? usbd_device_states[x] : "UNKNOWN")
+
+__maybe_unused static char *usbd_device_requests[] = {
+	"GET STATUS",		/* 0 */
+	"CLEAR FEATURE",	/* 1 */
+	"RESERVED",		/* 2 */
+	"SET FEATURE",		/* 3 */
+	"RESERVED",		/* 4 */
+	"SET ADDRESS",		/* 5 */
+	"GET DESCRIPTOR",	/* 6 */
+	"SET DESCRIPTOR",	/* 7 */
+	"GET CONFIGURATION",	/* 8 */
+	"SET CONFIGURATION",	/* 9 */
+	"GET INTERFACE",	/* 10 */
+	"SET INTERFACE",	/* 11 */
+	"SYNC FRAME",		/* 12 */
+};
+
+#define USBD_DEVICE_REQUESTS(x) (((unsigned int)x <= USB_REQ_SYNCH_FRAME) ? usbd_device_requests[x] : "UNKNOWN")
+
 /* EP0 Configuration Set ********************************************************************* */
 
 
diff --git a/include/usbdevice.h b/include/usbdevice.h
index f479724e37..611cd6e4ab 100644
--- a/include/usbdevice.h
+++ b/include/usbdevice.h
@@ -264,8 +264,6 @@ struct usb_bus_instance;
 #define USB_REQ_SET_INTERFACE		0x0B
 #define USB_REQ_SYNCH_FRAME		0x0C
 
-#define USBD_DEVICE_REQUESTS(x) (((unsigned int)x <= USB_REQ_SYNCH_FRAME) ? usbd_device_requests[x] : "UNKNOWN")
-
 /*
  * HID requests
  */
@@ -332,9 +330,6 @@ struct usb_bus_instance;
 #define USB_DESCRIPTOR_TYPE_HID				0x21
 #define USB_DESCRIPTOR_TYPE_REPORT			0x22
 
-#define USBD_DEVICE_DESCRIPTORS(x) (((unsigned int)x <= USB_DESCRIPTOR_TYPE_INTERFACE_POWER) ? \
-		usbd_device_descriptors[x] : "UNKNOWN")
-
 /*
  * standard feature selectors
  */
@@ -388,8 +383,6 @@ typedef enum usb_device_state {
 	STATE_UNKNOWN,		/* destroyed */
 } usb_device_state_t;
 
-#define USBD_DEVICE_STATE(x) (((unsigned int)x <= STATE_UNKNOWN) ? usbd_device_states[x] : "UNKNOWN")
-
 /*
  * Device status
  *
@@ -402,8 +395,6 @@ typedef enum usb_device_status {
 	USBD_CLOSING,		/* we are currently closing */
 } usb_device_status_t;
 
-#define USBD_DEVICE_STATUS(x) (((unsigned int)x <= USBD_CLOSING) ? usbd_device_status[x] : "UNKNOWN")
-
 /*
  * Device Events
  *
@@ -617,12 +608,6 @@ struct usb_bus_instance {
 
 };
 
-extern char *usbd_device_events[];
-extern char *usbd_device_states[];
-extern char *usbd_device_status[];
-extern char *usbd_device_requests[];
-extern char *usbd_device_descriptors[];
-
 void urb_link_init (urb_link * ul);
 void urb_detach (struct urb *urb);
 urb_link *first_urb_link (urb_link * hd);