Index: uspace/lib/c/include/ipc/dev_iface.h
===================================================================
--- uspace/lib/c/include/ipc/dev_iface.h	(revision 8b1e15ac9100f7b9da56e372d2f441ba44db6fcc)
+++ uspace/lib/c/include/ipc/dev_iface.h	(revision 6dd929cc1feb451d38f45065e8ed2de43c83c6bc)
@@ -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 8b1e15ac9100f7b9da56e372d2f441ba44db6fcc)
+++ uspace/lib/c/include/ipc/kbd.h	(revision 6dd929cc1feb451d38f45065e8ed2de43c83c6bc)
@@ -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;