Index: uspace/lib/c/generic/as.c
===================================================================
--- uspace/lib/c/generic/as.c	(revision 0b378820b4861f67ea1335ef6260a5c98a59c64c)
+++ uspace/lib/c/generic/as.c	(revision 9e809049359908fb13cd4bb5e3a515e55043a2d1)
@@ -35,4 +35,5 @@
 #include <as.h>
 #include <libc.h>
+#include <errno.h>
 #include <unistd.h>
 #include <align.h>
@@ -114,4 +115,30 @@
 }
 
+/** Find mapping to physical address.
+ *
+ * @param address Virtual address in question (virtual).
+ * @param[out] frame Frame address (physical).
+ * @return Error code.
+ * @retval EOK No error, @p frame holds the translation.
+ * @retval ENOENT Mapping not found.
+ */
+int as_get_physical_mapping(void *address, uintptr_t *frame)
+{
+	uintptr_t tmp_frame;
+	uintptr_t virt = (uintptr_t) address;
+	
+	int rc = (int) __SYSCALL2(SYS_PAGE_FIND_MAPPING,
+	    (sysarg_t) virt, (sysarg_t) &tmp_frame);
+	if (rc != EOK) {
+		return rc;
+	}
+	
+	if (frame != NULL) {
+		*frame = tmp_frame;
+	}
+	
+	return EOK;
+}
+
 /** @}
  */
Index: uspace/lib/c/include/as.h
===================================================================
--- uspace/lib/c/include/as.h	(revision 0b378820b4861f67ea1335ef6260a5c98a59c64c)
+++ uspace/lib/c/include/as.h	(revision 9e809049359908fb13cd4bb5e3a515e55043a2d1)
@@ -60,4 +60,5 @@
 extern void *set_maxheapsize(size_t mhs);
 extern void * as_get_mappable_page(size_t sz);
+extern int as_get_physical_mapping(void *address, uintptr_t *frame);
 
 #endif
Index: uspace/lib/c/include/ipc/dev_iface.h
===================================================================
--- uspace/lib/c/include/ipc/dev_iface.h	(revision 0b378820b4861f67ea1335ef6260a5c98a59c64c)
+++ uspace/lib/c/include/ipc/dev_iface.h	(revision 9e809049359908fb13cd4bb5e3a515e55043a2d1)
@@ -37,4 +37,10 @@
 	HW_RES_DEV_IFACE = 0,
 	CHAR_DEV_IFACE,
+
+	/** Interface provided by any USB device. */
+	USB_DEV_IFACE,
+	/** Interface provided by USB host controller. */
+	USBHC_DEV_IFACE,
+
 	DEV_IFACE_MAX
 } dev_inferface_idx_t;
@@ -48,4 +54,14 @@
 	DEV_IFACE_ID(DEV_FIRST_CUSTOM_METHOD_IDX)
 
+/*
+ * The first argument is actually method (as the "real" method is used
+ * for indexing into interfaces.
+ */
+
+#define DEV_IPC_GET_ARG1(call) IPC_GET_ARG2((call))
+#define DEV_IPC_GET_ARG2(call) IPC_GET_ARG3((call))
+#define DEV_IPC_GET_ARG3(call) IPC_GET_ARG4((call))
+#define DEV_IPC_GET_ARG4(call) IPC_GET_ARG5((call))
+
 
 #endif
Index: uspace/lib/c/include/ipc/kbd.h
===================================================================
--- uspace/lib/c/include/ipc/kbd.h	(revision 0b378820b4861f67ea1335ef6260a5c98a59c64c)
+++ uspace/lib/c/include/ipc/kbd.h	(revision 9e809049359908fb13cd4bb5e3a515e55043a2d1)
@@ -39,7 +39,8 @@
 
 #include <ipc/common.h>
+#include <ipc/dev_iface.h>
 
 typedef enum {
-	KBD_YIELD = IPC_FIRST_USER_METHOD,
+	KBD_YIELD = DEV_FIRST_CUSTOM_METHOD,
 	KBD_RECLAIM
 } kbd_request_t;