diff --git a/drivers/scsi/mac53c94.c b/drivers/scsi/mac53c94.c
new file mode 100644
index 0000000..3ef2a14
--- /dev/null
+++ b/drivers/scsi/mac53c94.c
@@ -0,0 +1,582 @@
+/*
+ * SCSI low-level driver for the 53c94 SCSI bus adaptor found
+ * on Power Macintosh computers, controlling the external SCSI chain.
+ * We assume the 53c94 is connected to a DBDMA (descriptor-based DMA)
+ * controller.
+ *
+ * Paul Mackerras, August 1996.
+ * Copyright (C) 1996 Paul Mackerras.
+ */
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/blkdev.h>
+#include <linux/proc_fs.h>
+#include <linux/stat.h>
+#include <linux/spinlock.h>
+#include <linux/interrupt.h>
+#include <asm/dbdma.h>
+#include <asm/io.h>
+#include <asm/pgtable.h>
+#include <asm/prom.h>
+#include <asm/system.h>
+#include <asm/pci-bridge.h>
+#include <asm/macio.h>
+
+#include <scsi/scsi.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_device.h>
+#include <scsi/scsi_host.h>
+
+#include "mac53c94.h"
+
+enum fsc_phase {
+	idle,
+	selecting,
+	dataing,
+	completing,
+	busfreeing,
+};
+
+struct fsc_state {
+	struct	mac53c94_regs __iomem *regs;
+	int	intr;
+	struct	dbdma_regs __iomem *dma;
+	int	dmaintr;
+	int	clk_freq;
+	struct	Scsi_Host *host;
+	struct scsi_cmnd *request_q;
+	struct scsi_cmnd *request_qtail;
+	struct scsi_cmnd *current_req;		/* req we're currently working on */
+	enum fsc_phase phase;		/* what we're currently trying to do */
+	struct dbdma_cmd *dma_cmds;	/* space for dbdma commands, aligned */
+	void	*dma_cmd_space;
+	struct	pci_dev *pdev;
+	dma_addr_t dma_addr;
+	struct macio_dev *mdev;
+};
+
+static void mac53c94_init(struct fsc_state *);
+static void mac53c94_start(struct fsc_state *);
+static void mac53c94_interrupt(int, void *, struct pt_regs *);
+static irqreturn_t do_mac53c94_interrupt(int, void *, struct pt_regs *);
+static void cmd_done(struct fsc_state *, int result);
+static void set_dma_cmds(struct fsc_state *, struct scsi_cmnd *);
+
+
+static int mac53c94_queue(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *))
+{
+	struct fsc_state *state;
+
+#if 0
+	if (cmd->sc_data_direction == DMA_TO_DEVICE) {
+		int i;
+		printk(KERN_DEBUG "mac53c94_queue %p: command is", cmd);
+		for (i = 0; i < cmd->cmd_len; ++i)
+			printk(" %.2x", cmd->cmnd[i]);
+		printk("\n" KERN_DEBUG "use_sg=%d request_bufflen=%d request_buffer=%p\n",
+		       cmd->use_sg, cmd->request_bufflen, cmd->request_buffer);
+	}
+#endif
+
+	cmd->scsi_done = done;
+	cmd->host_scribble = NULL;
+
+	state = (struct fsc_state *) cmd->device->host->hostdata;
+
+	if (state->request_q == NULL)
+		state->request_q = cmd;
+	else
+		state->request_qtail->host_scribble = (void *) cmd;
+	state->request_qtail = cmd;
+
+	if (state->phase == idle)
+		mac53c94_start(state);
+
+	return 0;
+}
+
+static int mac53c94_abort(struct scsi_cmnd *cmd)
+{
+	return FAILED;
+}
+
+static int mac53c94_host_reset(struct scsi_cmnd *cmd)
+{
+	struct fsc_state *state = (struct fsc_state *) cmd->device->host->hostdata;
+	struct mac53c94_regs __iomem *regs = state->regs;
+	struct dbdma_regs __iomem *dma = state->dma;
+
+	writel((RUN|PAUSE|FLUSH|WAKE) << 16, &dma->control);
+	writeb(CMD_SCSI_RESET, &regs->command);	/* assert RST */
+	udelay(100);			/* leave it on for a while (>= 25us) */
+	writeb(CMD_RESET, &regs->command);
+	udelay(20);
+	mac53c94_init(state);
+	writeb(CMD_NOP, &regs->command);
+	return SUCCESS;
+}
+
+static void mac53c94_init(struct fsc_state *state)
+{
+	struct mac53c94_regs __iomem *regs = state->regs;
+	struct dbdma_regs __iomem *dma = state->dma;
+	int x;
+
+	writeb(state->host->this_id | CF1_PAR_ENABLE, &regs->config1);
+	writeb(TIMO_VAL(250), &regs->sel_timeout);	/* 250ms */
+	writeb(CLKF_VAL(state->clk_freq), &regs->clk_factor);
+	writeb(CF2_FEATURE_EN, &regs->config2);
+	writeb(0, &regs->config3);
+	writeb(0, &regs->sync_period);
+	writeb(0, &regs->sync_offset);
+	x = readb(&regs->interrupt);
+	writel((RUN|PAUSE|FLUSH|WAKE) << 16, &dma->control);
+}
+
+/*
+ * Start the next command for a 53C94.
+ * Should be called with interrupts disabled.
+ */
+static void mac53c94_start(struct fsc_state *state)
+{
+	struct scsi_cmnd *cmd;
+	struct mac53c94_regs __iomem *regs = state->regs;
+	int i;
+
+	if (state->phase != idle || state->current_req != NULL)
+		panic("inappropriate mac53c94_start (state=%p)", state);
+	if (state->request_q == NULL)
+		return;
+	state->current_req = cmd = state->request_q;
+	state->request_q = (struct scsi_cmnd *) cmd->host_scribble;
+
+	/* Off we go */
+	writeb(0, &regs->count_lo);
+	writeb(0, &regs->count_mid);
+	writeb(0, &regs->count_hi);
+	writeb(CMD_NOP + CMD_DMA_MODE, &regs->command);
+	udelay(1);
+	writeb(CMD_FLUSH, &regs->command);
+	udelay(1);
+	writeb(cmd->device->id, &regs->dest_id);
+	writeb(0, &regs->sync_period);
+	writeb(0, &regs->sync_offset);
+
+	/* load the command into the FIFO */
+	for (i = 0; i < cmd->cmd_len; ++i)
+		writeb(cmd->cmnd[i], &regs->fifo);
+
+	/* do select without ATN XXX */
+	writeb(CMD_SELECT, &regs->command);
+	state->phase = selecting;
+
+	if (cmd->use_sg > 0 || cmd->request_bufflen != 0)
+		set_dma_cmds(state, cmd);
+}
+
+static irqreturn_t do_mac53c94_interrupt(int irq, void *dev_id, struct pt_regs *ptregs)
+{
+	unsigned long flags;
+	struct Scsi_Host *dev = ((struct fsc_state *) dev_id)->current_req->device->host;
+	
+	spin_lock_irqsave(dev->host_lock, flags);
+	mac53c94_interrupt(irq, dev_id, ptregs);
+	spin_unlock_irqrestore(dev->host_lock, flags);
+	return IRQ_HANDLED;
+}
+
+static void mac53c94_interrupt(int irq, void *dev_id, struct pt_regs *ptregs)
+{
+	struct fsc_state *state = (struct fsc_state *) dev_id;
+	struct mac53c94_regs __iomem *regs = state->regs;
+	struct dbdma_regs __iomem *dma = state->dma;
+	struct scsi_cmnd *cmd = state->current_req;
+	int nb, stat, seq, intr;
+	static int mac53c94_errors;
+
+	/*
+	 * Apparently, reading the interrupt register unlatches
+	 * the status and sequence step registers.
+	 */
+	seq = readb(&regs->seqstep);
+	stat = readb(&regs->status);
+	intr = readb(&regs->interrupt);
+
+#if 0
+	printk(KERN_DEBUG "mac53c94_intr, intr=%x stat=%x seq=%x phase=%d\n",
+	       intr, stat, seq, state->phase);
+#endif
+
+	if (intr & INTR_RESET) {
+		/* SCSI bus was reset */
+		printk(KERN_INFO "external SCSI bus reset detected\n");
+		writeb(CMD_NOP, &regs->command);
+		writel(RUN << 16, &dma->control);	/* stop dma */
+		cmd_done(state, DID_RESET << 16);
+		return;
+	}
+	if (intr & INTR_ILL_CMD) {
+		printk(KERN_ERR "53c94: invalid cmd, intr=%x stat=%x seq=%x phase=%d\n",
+		       intr, stat, seq, state->phase);
+		cmd_done(state, DID_ERROR << 16);
+		return;
+	}
+	if (stat & STAT_ERROR) {
+#if 0
+		/* XXX these seem to be harmless? */
+		printk("53c94: bad error, intr=%x stat=%x seq=%x phase=%d\n",
+		       intr, stat, seq, state->phase);
+#endif
+		++mac53c94_errors;
+		writeb(CMD_NOP + CMD_DMA_MODE, &regs->command);
+	}
+	if (cmd == 0) {
+		printk(KERN_DEBUG "53c94: interrupt with no command active?\n");
+		return;
+	}
+	if (stat & STAT_PARITY) {
+		printk(KERN_ERR "mac53c94: parity error\n");
+		cmd_done(state, DID_PARITY << 16);
+		return;
+	}
+	switch (state->phase) {
+	case selecting:
+		if (intr & INTR_DISCONNECT) {
+			/* selection timed out */
+			cmd_done(state, DID_BAD_TARGET << 16);
+			return;
+		}
+		if (intr != INTR_BUS_SERV + INTR_DONE) {
+			printk(KERN_DEBUG "got intr %x during selection\n", intr);
+			cmd_done(state, DID_ERROR << 16);
+			return;
+		}
+		if ((seq & SS_MASK) != SS_DONE) {
+			printk(KERN_DEBUG "seq step %x after command\n", seq);
+			cmd_done(state, DID_ERROR << 16);
+			return;
+		}
+		writeb(CMD_NOP, &regs->command);
+		/* set DMA controller going if any data to transfer */
+		if ((stat & (STAT_MSG|STAT_CD)) == 0
+		    && (cmd->use_sg > 0 || cmd->request_bufflen != 0)) {
+			nb = cmd->SCp.this_residual;
+			if (nb > 0xfff0)
+				nb = 0xfff0;
+			cmd->SCp.this_residual -= nb;
+			writeb(nb, &regs->count_lo);
+			writeb(nb >> 8, &regs->count_mid);
+			writeb(CMD_DMA_MODE + CMD_NOP, &regs->command);
+			writel(virt_to_phys(state->dma_cmds), &dma->cmdptr);
+			writel((RUN << 16) | RUN, &dma->control);
+			writeb(CMD_DMA_MODE + CMD_XFER_DATA, &regs->command);
+			state->phase = dataing;
+			break;
+		} else if ((stat & STAT_PHASE) == STAT_CD + STAT_IO) {
+			/* up to status phase already */
+			writeb(CMD_I_COMPLETE, &regs->command);
+			state->phase = completing;
+		} else {
+			printk(KERN_DEBUG "in unexpected phase %x after cmd\n",
+			       stat & STAT_PHASE);
+			cmd_done(state, DID_ERROR << 16);
+			return;
+		}
+		break;
+
+	case dataing:
+		if (intr != INTR_BUS_SERV) {
+			printk(KERN_DEBUG "got intr %x before status\n", intr);
+			cmd_done(state, DID_ERROR << 16);
+			return;
+		}
+		if (cmd->SCp.this_residual != 0
+		    && (stat & (STAT_MSG|STAT_CD)) == 0) {
+			/* Set up the count regs to transfer more */
+			nb = cmd->SCp.this_residual;
+			if (nb > 0xfff0)
+				nb = 0xfff0;
+			cmd->SCp.this_residual -= nb;
+			writeb(nb, &regs->count_lo);
+			writeb(nb >> 8, &regs->count_mid);
+			writeb(CMD_DMA_MODE + CMD_NOP, &regs->command);
+			writeb(CMD_DMA_MODE + CMD_XFER_DATA, &regs->command);
+			break;
+		}
+		if ((stat & STAT_PHASE) != STAT_CD + STAT_IO) {
+			printk(KERN_DEBUG "intr %x before data xfer complete\n", intr);
+		}
+		writel(RUN << 16, &dma->control);	/* stop dma */
+		if (cmd->use_sg != 0) {
+			pci_unmap_sg(state->pdev,
+				(struct scatterlist *)cmd->request_buffer,
+				cmd->use_sg, cmd->sc_data_direction);
+		} else {
+			pci_unmap_single(state->pdev, state->dma_addr,
+				cmd->request_bufflen, cmd->sc_data_direction);
+		}
+		/* should check dma status */
+		writeb(CMD_I_COMPLETE, &regs->command);
+		state->phase = completing;
+		break;
+	case completing:
+		if (intr != INTR_DONE) {
+			printk(KERN_DEBUG "got intr %x on completion\n", intr);
+			cmd_done(state, DID_ERROR << 16);
+			return;
+		}
+		cmd->SCp.Status = readb(&regs->fifo);
+		cmd->SCp.Message = readb(&regs->fifo);
+		cmd->result = CMD_ACCEPT_MSG;
+		writeb(CMD_ACCEPT_MSG, &regs->command);
+		state->phase = busfreeing;
+		break;
+	case busfreeing:
+		if (intr != INTR_DISCONNECT) {
+			printk(KERN_DEBUG "got intr %x when expected disconnect\n", intr);
+		}
+		cmd_done(state, (DID_OK << 16) + (cmd->SCp.Message << 8)
+			 + cmd->SCp.Status);
+		break;
+	default:
+		printk(KERN_DEBUG "don't know about phase %d\n", state->phase);
+	}
+}
+
+static void cmd_done(struct fsc_state *state, int result)
+{
+	struct scsi_cmnd *cmd;
+
+	cmd = state->current_req;
+	if (cmd != 0) {
+		cmd->result = result;
+		(*cmd->scsi_done)(cmd);
+		state->current_req = NULL;
+	}
+	state->phase = idle;
+	mac53c94_start(state);
+}
+
+/*
+ * Set up DMA commands for transferring data.
+ */
+static void set_dma_cmds(struct fsc_state *state, struct scsi_cmnd *cmd)
+{
+	int i, dma_cmd, total;
+	struct scatterlist *scl;
+	struct dbdma_cmd *dcmds;
+	dma_addr_t dma_addr;
+	u32 dma_len;
+
+	dma_cmd = cmd->sc_data_direction == DMA_TO_DEVICE ?
+			OUTPUT_MORE : INPUT_MORE;
+	dcmds = state->dma_cmds;
+	if (cmd->use_sg > 0) {
+		int nseg;
+
+		total = 0;
+		scl = (struct scatterlist *) cmd->buffer;
+		nseg = pci_map_sg(state->pdev, scl, cmd->use_sg,
+				cmd->sc_data_direction);
+		for (i = 0; i < nseg; ++i) {
+			dma_addr = sg_dma_address(scl);
+			dma_len = sg_dma_len(scl);
+			if (dma_len > 0xffff)
+				panic("mac53c94: scatterlist element >= 64k");
+			total += dma_len;
+			st_le16(&dcmds->req_count, dma_len);
+			st_le16(&dcmds->command, dma_cmd);
+			st_le32(&dcmds->phy_addr, dma_addr);
+			dcmds->xfer_status = 0;
+			++scl;
+			++dcmds;
+		}
+	} else {
+		total = cmd->request_bufflen;
+		if (total > 0xffff)
+			panic("mac53c94: transfer size >= 64k");
+		dma_addr = pci_map_single(state->pdev, cmd->request_buffer,
+					  total, cmd->sc_data_direction);
+		state->dma_addr = dma_addr;
+		st_le16(&dcmds->req_count, total);
+		st_le32(&dcmds->phy_addr, dma_addr);
+		dcmds->xfer_status = 0;
+		++dcmds;
+	}
+	dma_cmd += OUTPUT_LAST - OUTPUT_MORE;
+	st_le16(&dcmds[-1].command, dma_cmd);
+	st_le16(&dcmds->command, DBDMA_STOP);
+	cmd->SCp.this_residual = total;
+}
+
+static struct scsi_host_template mac53c94_template = {
+	.proc_name	= "53c94",
+	.name		= "53C94",
+	.queuecommand	= mac53c94_queue,
+	.eh_abort_handler = mac53c94_abort,
+	.eh_host_reset_handler = mac53c94_host_reset,
+	.can_queue	= 1,
+	.this_id	= 7,
+	.sg_tablesize	= SG_ALL,
+	.cmd_per_lun	= 1,
+	.use_clustering	= DISABLE_CLUSTERING,
+};
+
+static int mac53c94_probe(struct macio_dev *mdev, const struct of_match *match)
+{
+	struct device_node *node = macio_get_of_node(mdev);
+	struct pci_dev *pdev = macio_get_pci_dev(mdev);
+	struct fsc_state *state;
+	struct Scsi_Host *host;
+	void *dma_cmd_space;
+	unsigned char *clkprop;
+	int proplen;
+
+	if (macio_resource_count(mdev) != 2 || macio_irq_count(mdev) != 2) {
+		printk(KERN_ERR "mac53c94: expected 2 addrs and intrs (got %d/%d)\n",
+		       node->n_addrs, node->n_intrs);
+		return -ENODEV;
+	}
+
+	if (macio_request_resources(mdev, "mac53c94") != 0) {
+       		printk(KERN_ERR "mac53c94: unable to request memory resources");
+		return -EBUSY;
+	}
+
+       	host = scsi_host_alloc(&mac53c94_template, sizeof(struct fsc_state));
+	if (host == NULL) {
+		printk(KERN_ERR "mac53c94: couldn't register host");
+		goto out_release;
+	}
+
+	state = (struct fsc_state *) host->hostdata;
+	macio_set_drvdata(mdev, state);
+	state->host = host;
+	state->pdev = pdev;
+	state->mdev = mdev;
+
+	state->regs = (struct mac53c94_regs __iomem *)
+		ioremap(macio_resource_start(mdev, 0), 0x1000);
+	state->intr = macio_irq(mdev, 0);
+	state->dma = (struct dbdma_regs __iomem *)
+		ioremap(macio_resource_start(mdev, 1), 0x1000);
+	state->dmaintr = macio_irq(mdev, 1);
+	if (state->regs == NULL || state->dma == NULL) {
+		printk(KERN_ERR "mac53c94: ioremap failed for %s\n",
+		       node->full_name);
+		goto out_free;
+	}
+
+       	clkprop = get_property(node, "clock-frequency", &proplen);
+       	if (clkprop == NULL || proplen != sizeof(int)) {
+       		printk(KERN_ERR "%s: can't get clock frequency, "
+       		       "assuming 25MHz\n", node->full_name);
+       		state->clk_freq = 25000000;
+       	} else
+       		state->clk_freq = *(int *)clkprop;
+
+       	/* Space for dma command list: +1 for stop command,
+       	 * +1 to allow for aligning.
+	 * XXX FIXME: Use DMA consistent routines
+	 */
+       	dma_cmd_space = kmalloc((host->sg_tablesize + 2) *
+       				sizeof(struct dbdma_cmd), GFP_KERNEL);
+       	if (dma_cmd_space == 0) {
+       		printk(KERN_ERR "mac53c94: couldn't allocate dma "
+       		       "command space for %s\n", node->full_name);
+       		goto out_free;
+       	}
+	state->dma_cmds = (struct dbdma_cmd *)DBDMA_ALIGN(dma_cmd_space);
+	memset(state->dma_cmds, 0, (host->sg_tablesize + 1)
+	       * sizeof(struct dbdma_cmd));
+	state->dma_cmd_space = dma_cmd_space;
+
+	mac53c94_init(state);
+
+	if (request_irq(state->intr, do_mac53c94_interrupt, 0, "53C94", state)) {
+		printk(KERN_ERR "mac53C94: can't get irq %d for %s\n",
+		       state->intr, node->full_name);
+		goto out_free_dma;
+	}
+
+	/* XXX FIXME: handle failure */
+	scsi_add_host(host, &mdev->ofdev.dev);
+	scsi_scan_host(host);
+
+	return 0;
+
+ out_free_dma:
+	kfree(state->dma_cmd_space);
+ out_free:
+	if (state->dma != NULL)
+		iounmap(state->dma);
+	if (state->regs != NULL)
+		iounmap(state->regs);
+	scsi_host_put(host);
+ out_release:
+	macio_release_resources(mdev);
+
+	return  -ENODEV;
+}
+
+static int mac53c94_remove(struct macio_dev *mdev)
+{
+	struct fsc_state *fp = (struct fsc_state *)macio_get_drvdata(mdev);
+	struct Scsi_Host *host = fp->host;
+
+	scsi_remove_host(host);
+
+	free_irq(fp->intr, fp);
+
+	if (fp->regs)
+		iounmap((void *) fp->regs);
+	if (fp->dma)
+		iounmap((void *) fp->dma);
+	kfree(fp->dma_cmd_space);
+
+	scsi_host_put(host);
+
+	macio_release_resources(mdev);
+
+	return 0;
+}
+
+
+static struct of_match mac53c94_match[] = 
+{
+	{
+	.name 		= "53c94",
+	.type		= OF_ANY_MATCH,
+	.compatible	= OF_ANY_MATCH
+	},
+	{},
+};
+
+static struct macio_driver mac53c94_driver = 
+{
+	.name 		= "mac53c94",
+	.match_table	= mac53c94_match,
+	.probe		= mac53c94_probe,
+	.remove		= mac53c94_remove,
+};
+
+
+static int __init init_mac53c94(void)
+{
+	return macio_register_driver(&mac53c94_driver);
+}
+
+static void __exit exit_mac53c94(void)
+{
+	return macio_unregister_driver(&mac53c94_driver);
+}
+
+module_init(init_mac53c94);
+module_exit(exit_mac53c94);
+
+MODULE_DESCRIPTION("PowerMac 53c94 SCSI driver");
+MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
+MODULE_LICENSE("GPL");