Index: uspace/lib/c/include/ipc/clock_ctl.h
===================================================================
--- uspace/lib/c/include/ipc/clock_ctl.h	(revision fa18523547f587da07046f2697155b9dae6897fa)
+++ uspace/lib/c/include/ipc/clock_ctl.h	(revision fa18523547f587da07046f2697155b9dae6897fa)
@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2012 Maurizio Lombardi
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ * - The name of the author may not be used to endorse or promote products
+ *   derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef LIBC_IPC_CLOCK_CTL_H_
+#define LIBC_IPC_CLOCK_CTL_H_
+
+#include <ipc/dev_iface.h>
+
+typedef enum {
+	CLOCK_GET_BATTERY_STATUS = DEV_FIRST_CUSTOM_METHOD,
+} clock_ctl_t;
+
+#endif
+
Index: uspace/lib/c/include/ipc/dev_iface.h
===================================================================
--- uspace/lib/c/include/ipc/dev_iface.h	(revision 6aae539df68d767b7b3864f2cd3ae3398af9dde1)
+++ uspace/lib/c/include/ipc/dev_iface.h	(revision fa18523547f587da07046f2697155b9dae6897fa)
@@ -52,4 +52,7 @@
 	USBHID_DEV_IFACE,
 
+	/** Interface provided by Real Time Clock devices */
+	CLOCK_DEV_IFACE,
+
 	DEV_IFACE_MAX
 } dev_inferface_idx_t;