Index: uspace/lib/usbdev/include/usb/dev/dp.h
===================================================================
--- uspace/lib/usbdev/include/usb/dev/dp.h	(revision 49bd7ae269d452086f2ec89e5fa8cfded6f942da)
+++ uspace/lib/usbdev/include/usb/dev/dp.h	(revision 8a121b1fdd1be03445fd6d5c9d9a38c69090c325)
@@ -59,5 +59,5 @@
 typedef struct {
 	/** Used descriptor nesting. */
-	usb_dp_descriptor_nesting_t *nesting;
+	const usb_dp_descriptor_nesting_t *nesting;
 } usb_dp_parser_t;
 
@@ -72,11 +72,13 @@
 } usb_dp_parser_data_t;
 
-uint8_t *usb_dp_get_nested_descriptor(usb_dp_parser_t *,
-    usb_dp_parser_data_t *, uint8_t *);
-uint8_t *usb_dp_get_sibling_descriptor(usb_dp_parser_t *,
-    usb_dp_parser_data_t *, uint8_t *, uint8_t *);
+typedef void (*walk_callback_t)(const uint8_t *, size_t, void *);
 
-void usb_dp_walk_simple(uint8_t *, size_t, usb_dp_descriptor_nesting_t *,
-    void (*)(uint8_t *, size_t, void *), void *);
+const uint8_t *usb_dp_get_nested_descriptor(const usb_dp_parser_t *,
+    const usb_dp_parser_data_t *, const uint8_t *);
+const uint8_t *usb_dp_get_sibling_descriptor(const usb_dp_parser_t *,
+    const usb_dp_parser_data_t *, const uint8_t *, const uint8_t *);
+
+void usb_dp_walk_simple(uint8_t *, size_t, const usb_dp_descriptor_nesting_t *,
+    walk_callback_t, void *);
 
 #endif
Index: uspace/lib/usbdev/include/usb/dev/driver.h
===================================================================
--- uspace/lib/usbdev/include/usb/dev/driver.h	(revision 49bd7ae269d452086f2ec89e5fa8cfded6f942da)
+++ uspace/lib/usbdev/include/usb/dev/driver.h	(revision 8a121b1fdd1be03445fd6d5c9d9a38c69090c325)
@@ -53,7 +53,7 @@
 typedef struct {
 	/** Interface descriptor. */
-	usb_standard_interface_descriptor_t *interface;
+	const usb_standard_interface_descriptor_t *interface;
 	/** Pointer to start of descriptor tree bound with this interface. */
-	uint8_t *nested_descriptors;
+	const uint8_t *nested_descriptors;
 	/** Size of data pointed by nested_descriptors in bytes. */
 	size_t nested_descriptors_size;