diff --git a/drivers/mca/mca-bus.c b/drivers/mca/mca-bus.c
new file mode 100644
index 0000000..ff9be67c
--- /dev/null
+++ b/drivers/mca/mca-bus.c
@@ -0,0 +1,149 @@
+/* -*- mode: c; c-basic-offset: 8 -*- */
+
+/*
+ * MCA bus support functions for sysfs.
+ *
+ * (C) 2002 James Bottomley <James.Bottomley@HansenPartnership.com>
+ *
+**-----------------------------------------------------------------------------
+**  
+**  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.
+**
+**-----------------------------------------------------------------------------
+ */
+
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/mca.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+
+/* Very few machines have more than one MCA bus.  However, there are
+ * those that do (Voyager 35xx/5xxx), so we do it this way for future
+ * expansion.  None that I know have more than 2 */
+static struct mca_bus *mca_root_busses[MAX_MCA_BUSSES];
+
+#define MCA_DEVINFO(i,s) { .pos = i, .name = s }
+
+struct mca_device_info {
+	short pos_id;		/* the 2 byte pos id for this card */
+	char name[DEVICE_NAME_SIZE];
+};
+
+static int mca_bus_match (struct device *dev, struct device_driver *drv)
+{
+	struct mca_device *mca_dev = to_mca_device (dev);
+	struct mca_driver *mca_drv = to_mca_driver (drv);
+	const short *mca_ids = mca_drv->id_table;
+	int i;
+
+	if (!mca_ids)
+		return 0;
+
+	for(i = 0; mca_ids[i]; i++) {
+		if (mca_ids[i] == mca_dev->pos_id) {
+			mca_dev->index = i;
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
+struct bus_type mca_bus_type = {
+	.name  = "MCA",
+	.match = mca_bus_match,
+};
+EXPORT_SYMBOL (mca_bus_type);
+
+static ssize_t mca_show_pos_id(struct device *dev, char *buf)
+{
+	/* four digits, \n and trailing \0 */
+	struct mca_device *mca_dev = to_mca_device(dev);
+	int len;
+
+	if(mca_dev->pos_id < MCA_DUMMY_POS_START)
+		len = sprintf(buf, "%04x\n", mca_dev->pos_id);
+	else
+		len = sprintf(buf, "none\n");
+	return len;
+}
+static ssize_t mca_show_pos(struct device *dev, char *buf)
+{
+	/* enough for 8 two byte hex chars plus space and new line */
+	int j, len=0;
+	struct mca_device *mca_dev = to_mca_device(dev);
+
+	for(j=0; j<8; j++)
+		len += sprintf(buf+len, "%02x ", mca_dev->pos[j]);
+	/* change last trailing space to new line */
+	buf[len-1] = '\n';
+	return len;
+}
+
+static DEVICE_ATTR(id, S_IRUGO, mca_show_pos_id, NULL);
+static DEVICE_ATTR(pos, S_IRUGO, mca_show_pos, NULL);
+
+int __init mca_register_device(int bus, struct mca_device *mca_dev)
+{
+	struct mca_bus *mca_bus = mca_root_busses[bus];
+
+	mca_dev->dev.parent = &mca_bus->dev;
+	mca_dev->dev.bus = &mca_bus_type;
+	sprintf (mca_dev->dev.bus_id, "%02d:%02X", bus, mca_dev->slot);
+	mca_dev->dma_mask = mca_bus->default_dma_mask;
+	mca_dev->dev.dma_mask = &mca_dev->dma_mask;
+	mca_dev->dev.coherent_dma_mask = mca_dev->dma_mask;
+
+	if (device_register(&mca_dev->dev))
+		return 0;
+
+	device_create_file(&mca_dev->dev, &dev_attr_id);
+	device_create_file(&mca_dev->dev, &dev_attr_pos);
+
+	return 1;
+}
+
+/* */
+struct mca_bus * __devinit mca_attach_bus(int bus)
+{
+	struct mca_bus *mca_bus;
+
+	if (unlikely(mca_root_busses[bus] != NULL)) {
+		/* This should never happen, but just in case */
+		printk(KERN_EMERG "MCA tried to add already existing bus %d\n",
+		       bus);
+		dump_stack();
+		return NULL;
+	}
+
+	mca_bus = kmalloc(sizeof(struct mca_bus), GFP_KERNEL);
+	if (!mca_bus)
+		return NULL;
+	memset(mca_bus, 0, sizeof(struct mca_bus));
+	sprintf(mca_bus->dev.bus_id,"mca%d",bus);
+	sprintf(mca_bus->name,"Host %s MCA Bridge", bus ? "Secondary" : "Primary");
+	device_register(&mca_bus->dev);
+
+	mca_root_busses[bus] = mca_bus;
+
+	return mca_bus;
+}
+
+int __init mca_system_init (void)
+{
+	return bus_register(&mca_bus_type);
+}