kms: Adds api to get at the kms file descriptor

This adds a cogl_kms_renderer_get_kms_fd() function that lets developers
access the kms file descriptor being used for controlling the kernel
mode setting.

Reviewed-by: Neil Roberts <neil@linux.intel.com>

cogl/cogl-kms-renderer.h

@@ -0,0 +1,51 @@
+/*
+ * Cogl
+ *
+ * An object oriented GL/GLES Abstraction/Utility Layer
+ *
+ * Copyright (C) 2011 Intel Corporation.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#if !defined(__COGL_H_INSIDE__) && !defined(CLUTTER_COMPILATION)
+#error "Only <cogl/cogl.h> can be included directly."
+#endif
+
+#ifndef __COGL_KMS_RENDERER_H__
+#define __COGL_KMS_RENDERER_H__
+
+#include <cogl/cogl-types.h>
+#include <cogl/cogl-renderer.h>
+
+G_BEGIN_DECLS
+
+/**
+ * cogl_kms_renderer_get_kms_fd:
+ * @renderer: A #CoglRenderer
+ *
+ * Queries the file descriptor Cogl is using internally for
+ * communicating with the kms driver.
+ *
+ * Return value: The kms file descriptor or -1 if no kms file
+ *               desriptor has been opened by Cogl.
+ * Stability: unstable
+ */
+int
+cogl_kms_renderer_get_kms_fd (CoglRenderer *renderer);
+
+G_END_DECLS
+#endif /* __COGL_KMS_RENDERER_H__ */