os: helper Attached_mmio

Genode::Attached_mmio is the fusion of Genode::Attached_io_mem_dataspace
and Genode::Mmio.

Ref #706

os/include/os/attached_mmio.h

@@ -0,0 +1,56 @@
+/*
+ * \brief  MMIO framework utility
+ * \author Martin Stein
+ * \date   2013-05-17
+ */
+
+/*
+ * Copyright (C) 2013 Genode Labs GmbH
+ *
+ * This file is part of the Genode OS framework, which is distributed
+ * under the terms of the GNU General Public License version 2.
+ */
+
+#ifndef _INCLUDE__OS__ATTACHED_MMIO_H_
+#define _INCLUDE__OS__ATTACHED_MMIO_H_
+
+/* Genode includes */
+#include <os/attached_io_mem_dataspace.h>
+#include <util/mmio.h>
+
+namespace Genode
+{
+	/**
+	 * Eases the application of the MMIO framework
+	 *
+	 * In the classical case the user wants device memory to be structured
+	 * by inheriting from Genode::Mmio and using its subclasses. As
+	 * prerequisite one needs to alloc the IO dataspace, attach it locally
+	 * and cast the received address. This helper undertakes all of this
+	 * generic work when inheriting from it.
+	 */
+	class Attached_mmio : public Attached_io_mem_dataspace,
+	                      public Mmio
+	{
+		public:
+
+			/**
+			 * Constructor
+			 *
+			 * \param base            base address of memory-mapped I/O resource
+			 * \param size            size of resource
+			 * \param write_combined  enable write combining for the resource
+			 *
+			 * \throw Parent::Service_denied
+			 * \throw Parent::Quota_exceeded
+			 * \throw Parent::Unavailable
+			 * \throw Rm_session::Attach_failed
+			 */
+			Attached_mmio(addr_t base, size_t size,
+			              bool write_combined = false)
+			: Attached_io_mem_dataspace(base, size, write_combined),
+			  Mmio((addr_t)local_addr<void>()) { }
+	};
+}
+
+#endif /* _INCLUDE__OS__ATTACHED_MMIO_H_ */