diff --git a/drivers/macintosh/via-maciisi.c b/drivers/macintosh/via-maciisi.c
new file mode 100644
index 0000000..a196697
--- /dev/null
+++ b/drivers/macintosh/via-maciisi.c
@@ -0,0 +1,661 @@
+/*
+ * Device driver for the IIsi-style ADB on some Mac LC and II-class machines
+ *
+ * Based on via-cuda.c and via-macii.c, as well as the original
+ * adb-bus.c, which in turn is somewhat influenced by (but uses no
+ * code from) the NetBSD HWDIRECT ADB code.  Original IIsi driver work
+ * was done by Robert Thompson and integrated into the old style
+ * driver by Michael Schmitz.
+ *
+ * Original sources (c) Alan Cox, Paul Mackerras, and others.
+ *
+ * Rewritten for Unified ADB by David Huggins-Daines <dhd@debian.org>
+ * 
+ * 7/13/2000- extensive changes by Andrew McPherson <andrew@macduff.dhs.org>
+ * Works about 30% of the time now.
+ */
+
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/adb.h>
+#include <linux/cuda.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <asm/macintosh.h>
+#include <asm/macints.h>
+#include <asm/machw.h>
+#include <asm/mac_via.h>
+
+static volatile unsigned char *via;
+
+/* VIA registers - spaced 0x200 bytes apart - only the ones we actually use */
+#define RS		0x200		/* skip between registers */
+#define B		0		/* B-side data */
+#define A		RS		/* A-side data */
+#define DIRB		(2*RS)		/* B-side direction (1=output) */
+#define DIRA		(3*RS)		/* A-side direction (1=output) */
+#define SR		(10*RS)		/* Shift register */
+#define ACR		(11*RS)		/* Auxiliary control register */
+#define IFR		(13*RS)		/* Interrupt flag register */
+#define IER		(14*RS)		/* Interrupt enable register */
+
+/* Bits in B data register: all active low */
+#define TREQ		0x08		/* Transfer request (input) */
+#define TACK		0x10		/* Transfer acknowledge (output) */
+#define TIP		0x20		/* Transfer in progress (output) */
+#define ST_MASK		0x30		/* mask for selecting ADB state bits */
+
+/* Bits in ACR */
+#define SR_CTRL		0x1c		/* Shift register control bits */
+#define SR_EXT		0x0c		/* Shift on external clock */
+#define SR_OUT		0x10		/* Shift out if 1 */
+
+/* Bits in IFR and IER */
+#define IER_SET		0x80		/* set bits in IER */
+#define IER_CLR		0		/* clear bits in IER */
+#define SR_INT		0x04		/* Shift register full/empty */
+#define SR_DATA		0x08		/* Shift register data */
+#define SR_CLOCK	0x10		/* Shift register clock */
+
+#define ADB_DELAY 150
+
+#undef DEBUG_MACIISI_ADB
+
+static struct adb_request* current_req = NULL;
+static struct adb_request* last_req = NULL;
+static unsigned char maciisi_rbuf[16];
+static unsigned char *reply_ptr = NULL;
+static int data_index;
+static int reading_reply;
+static int reply_len;
+static int tmp;
+static int need_sync;
+
+static enum maciisi_state {
+    idle,
+    sending,
+    reading,
+} maciisi_state;
+
+static int maciisi_probe(void);
+static int maciisi_init(void);
+static int maciisi_send_request(struct adb_request* req, int sync);
+static void maciisi_sync(struct adb_request *req);
+static int maciisi_write(struct adb_request* req);
+static irqreturn_t maciisi_interrupt(int irq, void* arg, struct pt_regs* regs);
+static void maciisi_input(unsigned char *buf, int nb, struct pt_regs *regs);
+static int maciisi_init_via(void);
+static void maciisi_poll(void);
+static int maciisi_start(void);
+
+struct adb_driver via_maciisi_driver = {
+	"Mac IIsi",
+	maciisi_probe,
+	maciisi_init,
+	maciisi_send_request,
+	NULL, /* maciisi_adb_autopoll, */
+	maciisi_poll,
+	NULL /* maciisi_reset_adb_bus */
+};
+
+static int
+maciisi_probe(void)
+{
+	if (macintosh_config->adb_type != MAC_ADB_IISI)
+		return -ENODEV;
+
+	via = via1;
+	return 0;
+}
+
+static int
+maciisi_init(void)
+{
+	int err;
+
+	if (via == NULL)
+		return -ENODEV;
+
+	if ((err = maciisi_init_via())) {
+		printk(KERN_ERR "maciisi_init: maciisi_init_via() failed, code %d\n", err);
+		via = NULL;
+		return err;
+	}
+
+	if (request_irq(IRQ_MAC_ADB, maciisi_interrupt, IRQ_FLG_LOCK | IRQ_FLG_FAST, 
+			"ADB", maciisi_interrupt)) {
+		printk(KERN_ERR "maciisi_init: can't get irq %d\n", IRQ_MAC_ADB);
+		return -EAGAIN;
+	}
+
+	printk("adb: Mac IIsi driver v0.2 for Unified ADB.\n");
+	return 0;
+}
+
+/* Flush data from the ADB controller */
+static void
+maciisi_stfu(void)
+{
+	int status = via[B] & (TIP|TREQ);
+
+	if (status & TREQ) {
+#ifdef DEBUG_MACIISI_ADB
+		printk (KERN_DEBUG "maciisi_stfu called with TREQ high!\n");
+#endif
+		return;
+	}
+	
+	udelay(ADB_DELAY);
+	via[ACR] &= ~SR_OUT;
+	via[IER] = IER_CLR | SR_INT;
+
+	udelay(ADB_DELAY);
+
+	status = via[B] & (TIP|TREQ);
+
+	if (!(status & TREQ))
+	{
+		via[B] |= TIP;
+
+		while(1)
+		{
+			int poll_timeout = ADB_DELAY * 5;
+			/* Poll for SR interrupt */
+			while (!(via[IFR] & SR_INT) && poll_timeout-- > 0)
+				status = via[B] & (TIP|TREQ);
+
+			tmp = via[SR]; /* Clear shift register */
+#ifdef DEBUG_MACIISI_ADB
+			printk(KERN_DEBUG "maciisi_stfu: status %x timeout %d data %x\n",
+			       status, poll_timeout, tmp);
+#endif	
+			if(via[B] & TREQ)
+				break;
+	
+			/* ACK on-off */
+			via[B] |= TACK;
+			udelay(ADB_DELAY);
+			via[B] &= ~TACK;
+		}
+
+		/* end frame */
+		via[B] &= ~TIP;
+		udelay(ADB_DELAY);
+	}
+
+	via[IER] = IER_SET | SR_INT;	
+}
+
+/* All specifically VIA-related initialization goes here */
+static int
+maciisi_init_via(void)
+{
+	int	i;
+	
+	/* Set the lines up. We want TREQ as input TACK|TIP as output */
+	via[DIRB] = (via[DIRB] | TACK | TIP) & ~TREQ;
+	/* Shift register on input */
+	via[ACR]  = (via[ACR] & ~SR_CTRL) | SR_EXT;
+#ifdef DEBUG_MACIISI_ADB
+	printk(KERN_DEBUG "maciisi_init_via: initial status %x\n", via[B] & (TIP|TREQ));
+#endif
+	/* Wipe any pending data and int */
+	tmp = via[SR];
+	/* Enable keyboard interrupts */
+	via[IER] = IER_SET | SR_INT;
+	/* Set initial state: idle */
+	via[B] &= ~(TACK|TIP);
+	/* Clear interrupt bit */
+	via[IFR] = SR_INT;
+
+	for(i = 0; i < 60; i++) {
+		udelay(ADB_DELAY);
+		maciisi_stfu();
+		udelay(ADB_DELAY);
+		if(via[B] & TREQ)
+			break;
+	}
+	if (i == 60)
+		printk(KERN_ERR "maciisi_init_via: bus jam?\n");
+
+	maciisi_state = idle;
+	need_sync = 0;
+
+	return 0;
+}
+
+/* Send a request, possibly waiting for a reply */
+static int
+maciisi_send_request(struct adb_request* req, int sync)
+{
+	int i;
+
+#ifdef DEBUG_MACIISI_ADB
+	static int dump_packet = 0;
+#endif
+
+	if (via == NULL) {
+		req->complete = 1;
+		return -ENXIO;
+	}
+
+#ifdef DEBUG_MACIISI_ADB
+	if (dump_packet) {
+		printk(KERN_DEBUG "maciisi_send_request:");
+		for (i = 0; i < req->nbytes; i++) {
+			printk(" %.2x", req->data[i]);
+		}
+		printk(" sync %d\n", sync);
+	}
+#endif
+
+	req->reply_expected = 1;
+	
+	i = maciisi_write(req);
+	if (i)
+	{
+		/* Normally, if a packet requires syncing, that happens at the end of
+		 * maciisi_send_request. But if the transfer fails, it will be restarted
+		 * by maciisi_interrupt(). We use need_sync to tell maciisi_interrupt
+		 * when to sync a packet that it sends out.
+		 * 
+		 * Suggestions on a better way to do this are welcome.
+		 */
+		if(i == -EBUSY && sync)
+			need_sync = 1;
+		else
+			need_sync = 0;
+		return i;
+	}
+	if(sync)
+		maciisi_sync(req);
+	
+	return 0;
+}
+
+/* Poll the ADB chip until the request completes */
+static void maciisi_sync(struct adb_request *req)
+{
+	int count = 0; 
+
+#ifdef DEBUG_MACIISI_ADB
+	printk(KERN_DEBUG "maciisi_sync called\n");
+#endif
+
+	/* If for some reason the ADB chip shuts up on us, we want to avoid an endless loop. */
+	while (!req->complete && count++ < 50) {
+		maciisi_poll();
+	}
+	/* This could be BAD... when the ADB controller doesn't respond
+	 * for this long, it's probably not coming back :-( */
+	if(count >= 50) /* Hopefully shouldn't happen */
+		printk(KERN_ERR "maciisi_send_request: poll timed out!\n");
+}
+
+/* Enqueue a request, and run the queue if possible */
+static int
+maciisi_write(struct adb_request* req)
+{
+	unsigned long flags;
+	int i;
+
+	/* We will accept CUDA packets - the VIA sends them to us, so
+           it figures that we should be able to send them to it */
+	if (req->nbytes < 2 || req->data[0] > CUDA_PACKET) {
+		printk(KERN_ERR "maciisi_write: packet too small or not an ADB or CUDA packet\n");
+		req->complete = 1;
+		return -EINVAL;
+	}
+	req->next = 0;
+	req->sent = 0;
+	req->complete = 0;
+	req->reply_len = 0;
+	
+	local_irq_save(flags);
+
+	if (current_req) {
+		last_req->next = req;
+		last_req = req;
+	} else {
+		current_req = req;
+		last_req = req;
+	}
+	if (maciisi_state == idle)
+	{
+		i = maciisi_start();
+		if(i != 0)
+		{
+			local_irq_restore(flags);
+			return i;
+		}
+	}
+	else
+	{
+#ifdef DEBUG_MACIISI_ADB
+		printk(KERN_DEBUG "maciisi_write: would start, but state is %d\n", maciisi_state);
+#endif
+		local_irq_restore(flags);
+		return -EBUSY;
+	}
+
+	local_irq_restore(flags);
+
+	return 0;
+}
+
+static int
+maciisi_start(void)
+{
+	struct adb_request* req;
+	int status;
+
+#ifdef DEBUG_MACIISI_ADB
+	status = via[B] & (TIP | TREQ);
+
+	printk(KERN_DEBUG "maciisi_start called, state=%d, status=%x, ifr=%x\n", maciisi_state, status, via[IFR]);
+#endif
+
+	if (maciisi_state != idle) {
+		/* shouldn't happen */
+		printk(KERN_ERR "maciisi_start: maciisi_start called when driver busy!\n");
+		return -EBUSY;
+	}
+
+	req = current_req;
+	if (req == NULL)
+		return -EINVAL;
+
+	status = via[B] & (TIP|TREQ);
+	if (!(status & TREQ)) {
+#ifdef DEBUG_MACIISI_ADB
+		printk(KERN_DEBUG "maciisi_start: bus busy - aborting\n");
+#endif
+		return -EBUSY;
+	}
+
+	/* Okay, send */
+#ifdef DEBUG_MACIISI_ADB
+	printk(KERN_DEBUG "maciisi_start: sending\n");
+#endif
+	/* Set state to active */
+	via[B] |= TIP;
+	/* ACK off */
+	via[B] &= ~TACK;
+	/* Delay */
+	udelay(ADB_DELAY);
+	/* Shift out and send */
+	via[ACR] |= SR_OUT;
+	via[SR] = req->data[0];
+	data_index = 1;
+	/* ACK on */
+	via[B] |= TACK;
+	maciisi_state = sending;
+
+	return 0;
+}
+
+void
+maciisi_poll(void)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	if (via[IFR] & SR_INT) {
+		maciisi_interrupt(0, 0, 0);
+	}
+	else /* avoid calling this function too quickly in a loop */
+		udelay(ADB_DELAY);
+
+	local_irq_restore(flags);
+}
+
+/* Shift register interrupt - this is *supposed* to mean that the
+   register is either full or empty. In practice, I have no idea what
+   it means :( */
+static irqreturn_t
+maciisi_interrupt(int irq, void* arg, struct pt_regs* regs)
+{
+	int status;
+	struct adb_request *req;
+#ifdef DEBUG_MACIISI_ADB
+	static int dump_reply = 0;
+#endif
+	int i;
+	unsigned long flags;
+
+	local_irq_save(flags);
+
+	status = via[B] & (TIP|TREQ);
+#ifdef DEBUG_MACIISI_ADB
+	printk(KERN_DEBUG "state %d status %x ifr %x\n", maciisi_state, status, via[IFR]);
+#endif
+
+	if (!(via[IFR] & SR_INT)) {
+		/* Shouldn't happen, we hope */
+		printk(KERN_ERR "maciisi_interrupt: called without interrupt flag set\n");
+		local_irq_restore(flags);
+		return IRQ_NONE;
+	}
+
+	/* Clear the interrupt */
+	/* via[IFR] = SR_INT; */
+
+ switch_start:
+	switch (maciisi_state) {
+	case idle:
+		if (status & TIP)
+			printk(KERN_ERR "maciisi_interrupt: state is idle but TIP asserted!\n");
+
+		if(!reading_reply)
+			udelay(ADB_DELAY);
+		/* Shift in */
+		via[ACR] &= ~SR_OUT;
+ 		/* Signal start of frame */
+		via[B] |= TIP;
+		/* Clear the interrupt (throw this value on the floor, it's useless) */
+		tmp = via[SR];
+		/* ACK adb chip, high-low */
+		via[B] |= TACK;
+		udelay(ADB_DELAY);
+		via[B] &= ~TACK;
+		reply_len = 0;
+		maciisi_state = reading;
+		if (reading_reply) {
+			reply_ptr = current_req->reply;
+		} else {
+			reply_ptr = maciisi_rbuf;
+		}
+		break;
+
+	case sending:
+		/* via[SR]; */
+		/* Set ACK off */
+		via[B] &= ~TACK;
+		req = current_req;
+
+		if (!(status & TREQ)) {
+			/* collision */
+			printk(KERN_ERR "maciisi_interrupt: send collision\n");
+			/* Set idle and input */
+			via[ACR] &= ~SR_OUT;
+			tmp = via[SR];
+			via[B] &= ~TIP;
+			/* Must re-send */
+			reading_reply = 0;
+			reply_len = 0;
+			maciisi_state = idle;
+			udelay(ADB_DELAY);
+			/* process this now, because the IFR has been cleared */
+			goto switch_start;
+		}
+
+		udelay(ADB_DELAY);
+
+		if (data_index >= req->nbytes) {
+			/* Sent the whole packet, put the bus back in idle state */
+			/* Shift in, we are about to read a reply (hopefully) */
+			via[ACR] &= ~SR_OUT;
+			tmp = via[SR];
+			/* End of frame */
+			via[B] &= ~TIP;
+			req->sent = 1;
+			maciisi_state = idle;
+			if (req->reply_expected) {
+				/* Note: only set this once we've
+                                   successfully sent the packet */
+				reading_reply = 1;
+			} else {
+				current_req = req->next;
+				if (req->done)
+					(*req->done)(req);
+				/* Do any queued requests now */
+				i = maciisi_start();
+				if(i == 0 && need_sync) {
+					/* Packet needs to be synced */
+					maciisi_sync(current_req);
+				}
+				if(i != -EBUSY)
+					need_sync = 0;
+			}
+		} else {
+			/* Sending more stuff */
+			/* Shift out */
+			via[ACR] |= SR_OUT;
+			/* Write */
+			via[SR] = req->data[data_index++];
+			/* Signal 'byte ready' */
+			via[B] |= TACK;
+		}
+		break;
+
+	case reading:
+		/* Shift in */
+		/* via[ACR] &= ~SR_OUT; */ /* Not in 2.2 */
+		if (reply_len++ > 16) {
+			printk(KERN_ERR "maciisi_interrupt: reply too long, aborting read\n");
+			via[B] |= TACK;
+			udelay(ADB_DELAY);
+			via[B] &= ~(TACK|TIP);
+			maciisi_state = idle;
+			i = maciisi_start();
+			if(i == 0 && need_sync) {
+				/* Packet needs to be synced */
+				maciisi_sync(current_req);
+			}
+			if(i != -EBUSY)
+				need_sync = 0;
+			break;
+		}
+		/* Read data */
+		*reply_ptr++ = via[SR];
+		status = via[B] & (TIP|TREQ);
+		/* ACK on/off */
+		via[B] |= TACK;
+		udelay(ADB_DELAY);
+		via[B] &= ~TACK;	
+		if (!(status & TREQ))
+			break; /* more stuff to deal with */
+		
+		/* end of frame */
+		via[B] &= ~TIP;
+		tmp = via[SR]; /* That's what happens in 2.2 */
+		udelay(ADB_DELAY); /* Give controller time to recover */
+
+		/* end of packet, deal with it */
+		if (reading_reply) {
+			req = current_req;
+			req->reply_len = reply_ptr - req->reply;
+			if (req->data[0] == ADB_PACKET) {
+				/* Have to adjust the reply from ADB commands */
+				if (req->reply_len <= 2 || (req->reply[1] & 2) != 0) {
+					/* the 0x2 bit indicates no response */
+					req->reply_len = 0;
+				} else {
+					/* leave just the command and result bytes in the reply */
+					req->reply_len -= 2;
+					memmove(req->reply, req->reply + 2, req->reply_len);
+				}
+			}
+#ifdef DEBUG_MACIISI_ADB
+			if (dump_reply) {
+				int i;
+				printk(KERN_DEBUG "maciisi_interrupt: reply is ");
+				for (i = 0; i < req->reply_len; ++i)
+					printk(" %.2x", req->reply[i]);
+				printk("\n");
+			}
+#endif
+			req->complete = 1;
+			current_req = req->next;
+			if (req->done)
+				(*req->done)(req);
+			/* Obviously, we got it */
+			reading_reply = 0;
+		} else {
+			maciisi_input(maciisi_rbuf, reply_ptr - maciisi_rbuf, regs);
+		}
+		maciisi_state = idle;
+		status = via[B] & (TIP|TREQ);
+		if (!(status & TREQ)) {
+			/* Timeout?! More likely, another packet coming in already */
+#ifdef DEBUG_MACIISI_ADB
+			printk(KERN_DEBUG "extra data after packet: status %x ifr %x\n",
+			       status, via[IFR]);
+#endif
+#if 0
+			udelay(ADB_DELAY);
+			via[B] |= TIP;
+
+			maciisi_state = reading;
+			reading_reply = 0;
+			reply_ptr = maciisi_rbuf;
+#else
+			/* Process the packet now */
+			reading_reply = 0;
+			goto switch_start;
+#endif
+			/* We used to do this... but the controller might actually have data for us */
+			/* maciisi_stfu(); */
+		}
+		else {
+			/* Do any queued requests now if possible */
+			i = maciisi_start();
+			if(i == 0 && need_sync) {
+				/* Packet needs to be synced */
+				maciisi_sync(current_req);
+			}
+			if(i != -EBUSY)
+				need_sync = 0;
+		}
+		break;
+
+	default:
+		printk("maciisi_interrupt: unknown maciisi_state %d?\n", maciisi_state);
+	}
+	local_irq_restore(flags);
+	return IRQ_HANDLED;
+}
+
+static void
+maciisi_input(unsigned char *buf, int nb, struct pt_regs *regs)
+{
+#ifdef DEBUG_MACIISI_ADB
+    int i;
+#endif
+
+    switch (buf[0]) {
+    case ADB_PACKET:
+	    adb_input(buf+2, nb-2, regs, buf[1] & 0x40);
+	    break;
+    default:
+#ifdef DEBUG_MACIISI_ADB
+	    printk(KERN_DEBUG "data from IIsi ADB (%d bytes):", nb);
+	    for (i = 0; i < nb; ++i)
+		    printk(" %.2x", buf[i]);
+	    printk("\n");
+#endif
+	    break;
+    }
+}