Staging: comedi: add 8255 driver

The classic in digital I/O.

From: David Schleef <ds@schleef.org>
Cc: Frank Mori Hess <fmhess@users.sourceforge.net>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/comedi/drivers/8255.h

+/*
+    module/8255.h
+    Header file for 8255
+
+    COMEDI - Linux Control and Measurement Device Interface
+    Copyright (C) 1998 David A. Schleef <ds@schleef.org>
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program 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 General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+
+#ifndef _8255_H
+#define _8255_H
+
+#include "../comedidev.h"
+
+#if defined(CONFIG_COMEDI_8255) || defined(CONFIG_COMEDI_8255_MODULE)
+
+int subdev_8255_init(comedi_device * dev, comedi_subdevice * s,
+	int (*cb) (int, int, int, unsigned long), unsigned long arg);
+int subdev_8255_init_irq(comedi_device * dev, comedi_subdevice * s,
+	int (*cb) (int, int, int, unsigned long), unsigned long arg);
+void subdev_8255_cleanup(comedi_device * dev, comedi_subdevice * s);
+void subdev_8255_interrupt(comedi_device * dev, comedi_subdevice * s);
+
+#else
+
+static inline int subdev_8255_init(comedi_device * dev, comedi_subdevice * s,
+	void *x, unsigned long y)
+{
+	printk("8255 support not configured -- disabling subdevice\n");
+
+	s->type = COMEDI_SUBD_UNUSED;
+
+	return 0;
+}
+
+static inline void subdev_8255_cleanup(comedi_device * dev,
+	comedi_subdevice * s)
+{
+}
+
+#endif
+
+#endif