4 files changed, 730 insertions, 348 deletions

diff --git a/arch/powerpc/platforms/powermac/feature.c b/arch/powerpc/platforms/powermac/feature.c
index d2915d64d45..b271b11583a 100644
--- a/arch/powerpc/platforms/powermac/feature.c
+++ b/arch/powerpc/platforms/powermac/feature.c
@@ -1677,124 +1677,6 @@ intrepid_shutdown(struct macio_chip *macio, int sleep_mode)
 }
 
 
-void pmac_tweak_clock_spreading(int enable)
-{
-	struct macio_chip *macio = &macio_chips[0];
-
-	/* Hack for doing clock spreading on some machines PowerBooks and
-	 * iBooks. This implements the "platform-do-clockspreading" OF
-	 * property as decoded manually on various models. For safety, we also
-	 * check the product ID in the device-tree in cases we'll whack the i2c
-	 * chip to make reasonably sure we won't set wrong values in there
-	 *
-	 * Of course, ultimately, we have to implement a real parser for
-	 * the platform-do-* stuff...
-	 */
-
-	if (macio->type == macio_intrepid) {
-		struct device_node *clock =
-			of_find_node_by_path("/uni-n@f8000000/hw-clock");
-		if (clock && get_property(clock, "platform-do-clockspreading",
-					  NULL)) {
-			printk(KERN_INFO "%sabling clock spreading on Intrepid"
-			       " ASIC\n", enable ? "En" : "Dis");
-			if (enable)
-				UN_OUT(UNI_N_CLOCK_SPREADING, 2);
-			else
-				UN_OUT(UNI_N_CLOCK_SPREADING, 0);
-			mdelay(40);
-		}
-		of_node_put(clock);
-	}
-
-	while (machine_is_compatible("PowerBook5,2") ||
-	       machine_is_compatible("PowerBook5,3") ||
-	       machine_is_compatible("PowerBook6,2") ||
-	       machine_is_compatible("PowerBook6,3")) {
-		struct device_node *ui2c = of_find_node_by_type(NULL, "i2c");
-		struct device_node *dt = of_find_node_by_name(NULL, "device-tree");
-		u8 buffer[9];
-		u32 *productID;
-		int i, rc, changed = 0;
-
-		if (dt == NULL)
-			break;
-		productID = (u32 *)get_property(dt, "pid#", NULL);
-		if (productID == NULL)
-			break;
-		while(ui2c) {
-			struct device_node *p = of_get_parent(ui2c);
-			if (p && !strcmp(p->name, "uni-n"))
-				break;
-			ui2c = of_find_node_by_type(ui2c, "i2c");
-		}
-		if (ui2c == NULL)
-			break;
-		DBG("Trying to bump clock speed for PID: %08x...\n", *productID);
-		rc = pmac_low_i2c_open(ui2c, 1);
-		if (rc != 0)
-			break;
-		pmac_low_i2c_setmode(ui2c, pmac_low_i2c_mode_combined);
-		rc = pmac_low_i2c_xfer(ui2c, 0xd2 | pmac_low_i2c_read, 0x80, buffer, 9);
-		DBG("read result: %d,", rc);
-		if (rc != 0) {
-			pmac_low_i2c_close(ui2c);
-			break;
-		}
-		for (i=0; i<9; i++)
-			DBG(" %02x", buffer[i]);
-		DBG("\n");
-
-		switch(*productID) {
-		case 0x1182:	/* AlBook 12" rev 2 */
-		case 0x1183:	/* iBook G4 12" */
-			buffer[0] = (buffer[0] & 0x8f) | 0x70;
-			buffer[2] = (buffer[2] & 0x7f) | 0x00;
-			buffer[5] = (buffer[5] & 0x80) | 0x31;
-			buffer[6] = (buffer[6] & 0x40) | 0xb0;
-			buffer[7] = (buffer[7] & 0x00) | (enable ? 0xc0 : 0xba);
-			buffer[8] = (buffer[8] & 0x00) | 0x30;
-			changed = 1;
-			break;
-		case 0x3142:	/* AlBook 15" (ATI M10) */
-		case 0x3143:	/* AlBook 17" (ATI M10) */
-			buffer[0] = (buffer[0] & 0xaf) | 0x50;
-			buffer[2] = (buffer[2] & 0x7f) | 0x00;
-			buffer[5] = (buffer[5] & 0x80) | 0x31;
-			buffer[6] = (buffer[6] & 0x40) | 0xb0;
-			buffer[7] = (buffer[7] & 0x00) | (enable ? 0xd0 : 0xc0);
-			buffer[8] = (buffer[8] & 0x00) | 0x30;
-			changed = 1;
-			break;
-		default:
-			DBG("i2c-hwclock: Machine model not handled\n");
-			break;
-		}
-		if (!changed) {
-			pmac_low_i2c_close(ui2c);
-			break;
-		}
-		printk(KERN_INFO "%sabling clock spreading on i2c clock chip\n",
-		       enable ? "En" : "Dis");
-
-		pmac_low_i2c_setmode(ui2c, pmac_low_i2c_mode_stdsub);
-		rc = pmac_low_i2c_xfer(ui2c, 0xd2 | pmac_low_i2c_write, 0x80, buffer, 9);
-		DBG("write result: %d,", rc);
-		pmac_low_i2c_setmode(ui2c, pmac_low_i2c_mode_combined);
-		rc = pmac_low_i2c_xfer(ui2c, 0xd2 | pmac_low_i2c_read, 0x80, buffer, 9);
-		DBG("read result: %d,", rc);
-		if (rc != 0) {
-			pmac_low_i2c_close(ui2c);
-			break;
-		}
-		for (i=0; i<9; i++)
-			DBG(" %02x", buffer[i]);
-		pmac_low_i2c_close(ui2c);
-		break;
-	}
-}
-
-
 static int
 core99_sleep(void)
 {
@@ -2980,12 +2862,6 @@ set_initial_features(void)
 		MACIO_BIC(HEATHROW_FCR, HRW_SOUND_POWER_N);
 	}
 
-	/* Some machine models need the clock chip to be properly setup for
-	 * clock spreading now. This should be a platform function but we
-	 * don't do these at the moment
-	 */
-	pmac_tweak_clock_spreading(1);
-
 #endif /* CONFIG_POWER4 */
 
 	/* On all machines, switch modem & serial ports off */
@@ -3013,9 +2889,6 @@ pmac_feature_init(void)
 		return;
 	}
 
-	/* Setup low-level i2c stuffs */
-	pmac_init_low_i2c();
-
 	/* Probe machine type */
 	if (probe_motherboard())
 		printk(KERN_WARNING "Unknown PowerMac !\n");
diff --git a/arch/powerpc/platforms/powermac/low_i2c.c b/arch/powerpc/platforms/powermac/low_i2c.c
index 606e0ed1373..f31d6a678b9 100644
--- a/arch/powerpc/platforms/powermac/low_i2c.c
+++ b/arch/powerpc/platforms/powermac/low_i2c.c
@@ -1,22 +1,34 @@
 /*
- *  arch/ppc/platforms/pmac_low_i2c.c
+ * arch/powerpc/platforms/powermac/low_i2c.c
  *
- *  Copyright (C) 2003 Ben. Herrenschmidt (benh@kernel.crashing.org)
+ *  Copyright (C) 2003-2005 Ben. Herrenschmidt (benh@kernel.crashing.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 file contains some low-level i2c access routines that
- *  need to be used by various bits of the PowerMac platform code
- *  at times where the real asynchronous & interrupt driven driver
- *  cannot be used. The API borrows some semantics from the darwin
- *  driver in order to ease the implementation of the platform
- *  properties parser
+ * The linux i2c layer isn't completely suitable for our needs for various
+ * reasons ranging from too late initialisation to semantics not perfectly
+ * matching some requirements of the apple platform functions etc...
+ *
+ * This file thus provides a simple low level unified i2c interface for
+ * powermac that covers the various types of i2c busses used in Apple machines.
+ * For now, keywest, PMU and SMU, though we could add Cuda, or other bit
+ * banging busses found on older chipstes in earlier machines if we ever need
+ * one of them.
+ *
+ * The drivers in this file are synchronous/blocking. In addition, the
+ * keywest one is fairly slow due to the use of msleep instead of interrupts
+ * as the interrupt is currently used by i2c-keywest. In the long run, we
+ * might want to get rid of those high-level interfaces to linux i2c layer
+ * either completely (converting all drivers) or replacing them all with a
+ * single stub driver on top of this one. Once done, the interrupt will be
+ * available for our use.
  */
 
 #undef DEBUG
+#undef DEBUG_LOW
 
 #include <linux/config.h>
 #include <linux/types.h>
@@ -25,15 +37,16 @@
 #include <linux/module.h>
 #include <linux/adb.h>
 #include <linux/pmu.h>
+#include <linux/delay.h>
+#include <linux/completion.h>
 #include <asm/keylargo.h>
 #include <asm/uninorth.h>
 #include <asm/io.h>
 #include <asm/prom.h>
 #include <asm/machdep.h>
+#include <asm/smu.h>
 #include <asm/pmac_low_i2c.h>
 
-#define MAX_LOW_I2C_HOST	4
-
 #ifdef DEBUG
 #define DBG(x...) do {\
 		printk(KERN_DEBUG "low_i2c:" x);	\
@@ -42,49 +55,54 @@
 #define DBG(x...)
 #endif
 
-struct low_i2c_host;
-
-typedef int (*low_i2c_func_t)(struct low_i2c_host *host, u8 addr, u8 sub, u8 *data, int len);
-
-struct low_i2c_host
-{
-	struct device_node	*np;		/* OF device node */
-	struct semaphore	mutex;		/* Access mutex for use by i2c-keywest */
-	low_i2c_func_t		func;		/* Access function */
-	unsigned int		is_open : 1;	/* Poor man's access control */
-	int			mode;		/* Current mode */
-	int			channel;	/* Current channel */
-	int			num_channels;	/* Number of channels */
-	void __iomem		*base;		/* For keywest-i2c, base address */
-	int			bsteps;		/* And register stepping */
-	int			speed;		/* And speed */
-};
-
-static struct low_i2c_host	low_i2c_hosts[MAX_LOW_I2C_HOST];
+#ifdef DEBUG_LOW
+#define DBG_LOW(x...) do {\
+		printk(KERN_DEBUG "low_i2c:" x);	\
+	} while(0)
+#else
+#define DBG_LOW(x...)
+#endif
 
-/* No locking is necessary on allocation, we are running way before
- * anything can race with us
+/*
+ * A bus structure. Each bus in the system has such a structure associated.
  */
-static struct low_i2c_host *find_low_i2c_host(struct device_node *np)
+struct pmac_i2c_bus
 {
-	int i;
+	struct list_head	link;
+	struct device_node	*controller;
+	struct device_node	*busnode;
+	int			type;
+	int			flags;
+	struct i2c_adapter	*adapter;
+	void			*hostdata;
+	int			channel;	/* some hosts have multiple */
+	int			mode;		/* current mode */
+	struct semaphore	sem;
+	int			opened;
+	int			polled;		/* open mode */
+
+	/* ops */
+	int (*open)(struct pmac_i2c_bus *bus);
+	void (*close)(struct pmac_i2c_bus *bus);
+	int (*xfer)(struct pmac_i2c_bus *bus, u8 addrdir, int subsize,
+		    u32 subaddr, u8 *data, int len);
+};
 
-	for (i = 0; i < MAX_LOW_I2C_HOST; i++)
-		if (low_i2c_hosts[i].np == np)
-			return &low_i2c_hosts[i];
-	return NULL;
-}
+static LIST_HEAD(pmac_i2c_busses);
 
 /*
- *
- * i2c-keywest implementation (UniNorth, U2, U3, Keylargo's)
- *
+ * Keywest implementation
  */
 
-/*
- * Keywest i2c definitions borrowed from drivers/i2c/i2c-keywest.h,
- * should be moved somewhere in include/asm-ppc/
- */
+struct pmac_i2c_host_kw
+{
+	struct semaphore	mutex;		/* Access mutex for use by
+						 * i2c-keywest */
+	void __iomem		*base;		/* register base address */
+	int			bsteps;		/* register stepping */
+	int			speed;		/* speed */
+};
+
 /* Register indices */
 typedef enum {
 	reg_mode = 0,
@@ -153,52 +171,56 @@ static const char *__kw_state_names[] = {
 	"state_dead"
 };
 
-static inline u8 __kw_read_reg(struct low_i2c_host *host, reg_t reg)
+static inline u8 __kw_read_reg(struct pmac_i2c_bus *bus, reg_t reg)
 {
+	struct pmac_i2c_host_kw *host = bus->hostdata;
 	return readb(host->base + (((unsigned int)reg) << host->bsteps));
 }
 
-static inline void __kw_write_reg(struct low_i2c_host *host, reg_t reg, u8 val)
+static inline void __kw_write_reg(struct pmac_i2c_bus *bus, reg_t reg, u8 val)
 {
+	struct pmac_i2c_host_kw *host = bus->hostdata;
 	writeb(val, host->base + (((unsigned)reg) << host->bsteps));
-	(void)__kw_read_reg(host, reg_subaddr);
+	(void)__kw_read_reg(bus, reg_subaddr);
 }
 
-#define kw_write_reg(reg, val)	__kw_write_reg(host, reg, val) 
-#define kw_read_reg(reg)	__kw_read_reg(host, reg) 
+#define kw_write_reg(reg, val)	__kw_write_reg(bus, reg, val)
+#define kw_read_reg(reg)	__kw_read_reg(bus, reg)
 
-
-/* Don't schedule, the g5 fan controller is too
- * timing sensitive
- */
-static u8 kw_wait_interrupt(struct low_i2c_host* host)
+static u8 kw_i2c_wait_interrupt(struct pmac_i2c_bus* bus)
 {
 	int i, j;
 	u8 isr;
 	
-	for (i = 0; i < 100000; i++) {
+	for (i = 0; i < 1000; i++) {
 		isr = kw_read_reg(reg_isr) & KW_I2C_IRQ_MASK;
 		if (isr != 0)
 			return isr;
 
 		/* This code is used with the timebase frozen, we cannot rely
-		 * on udelay ! For now, just use a bogus loop
+		 * on udelay nor schedule when in polled mode !
+		 * For now, just use a bogus loop....
 		 */
-		for (j = 1; j < 10000; j++)
-			mb();
+		if (bus->polled) {
+			for (j = 1; j < 1000000; j++)
+				mb();
+		} else
+			msleep(1);
 	}
 	return isr;
 }
 
-static int kw_handle_interrupt(struct low_i2c_host *host, int state, int rw, int *rc, u8 **data, int *len, u8 isr)
+static int kw_i2c_handle_interrupt(struct pmac_i2c_bus *bus, int state, int rw,
+				   int *rc, u8 **data, int *len, u8 isr)
 {
 	u8 ack;
 
-	DBG("kw_handle_interrupt(%s, isr: %x)\n", __kw_state_names[state], isr);
+	DBG_LOW("kw_handle_interrupt(%s, isr: %x)\n",
+		__kw_state_names[state], isr);
 
 	if (isr == 0) {
 		if (state != state_stop) {
-			DBG("KW: Timeout !\n");
+			DBG_LOW("KW: Timeout !\n");
 			*rc = -EIO;
 			goto stop;
 		}
@@ -220,15 +242,16 @@ static int kw_handle_interrupt(struct low_i2c_host *host, int state, int rw, int
 			*rc = -EIO;
 			goto stop;
 		}
-		if ((ack & KW_I2C_STAT_LAST_AAK) == 0) {			
+		if ((ack & KW_I2C_STAT_LAST_AAK) == 0) {
 			*rc = -ENODEV;
-			DBG("KW: NAK on address\n");
+			DBG_LOW("KW: NAK on address\n");
 			return state_stop;		     
 		} else {
 			if (rw) {
 				state = state_read;
 				if (*len > 1)
-					kw_write_reg(reg_control, KW_I2C_CTL_AAK);
+					kw_write_reg(reg_control,
+						     KW_I2C_CTL_AAK);
 			} else {
 				state = state_write;
 				kw_write_reg(reg_data, **data);
@@ -250,7 +273,7 @@ static int kw_handle_interrupt(struct low_i2c_host *host, int state, int rw, int
 		} else if (state == state_write) {
 			ack = kw_read_reg(reg_status);
 			if ((ack & KW_I2C_STAT_LAST_AAK) == 0) {
-				DBG("KW: nack on data write\n");
+				DBG_LOW("KW: nack on data write\n");
 				*rc = -EIO;
 				goto stop;
 			} else if (*len) {
@@ -291,35 +314,57 @@ static int kw_handle_interrupt(struct low_i2c_host *host, int state, int rw, int
 	return state_stop;
 }
 
-static int keywest_low_i2c_func(struct low_i2c_host *host, u8 addr, u8 subaddr, u8 *data, int len)
+static int kw_i2c_open(struct pmac_i2c_bus *bus)
 {
+	struct pmac_i2c_host_kw *host = bus->hostdata;
+	down(&host->mutex);
+	return 0;
+}
+
+static void kw_i2c_close(struct pmac_i2c_bus *bus)
+{
+	struct pmac_i2c_host_kw *host = bus->hostdata;
+	up(&host->mutex);
+}
+
+static int kw_i2c_xfer(struct pmac_i2c_bus *bus, u8 addrdir, int subsize,
+		       u32 subaddr, u8 *data, int len)
+{
+	struct pmac_i2c_host_kw *host = bus->hostdata;
 	u8 mode_reg = host->speed;
 	int state = state_addr;
 	int rc = 0;
 
 	/* Setup mode & subaddress if any */
-	switch(host->mode) {
-	case pmac_low_i2c_mode_dumb:
-		printk(KERN_ERR "low_i2c: Dumb mode not supported !\n");
+	switch(bus->mode) {
+	case pmac_i2c_mode_dumb:
 		return -EINVAL;
-	case pmac_low_i2c_mode_std:
+	case pmac_i2c_mode_std:
 		mode_reg |= KW_I2C_MODE_STANDARD;
+		if (subsize != 0)
+			return -EINVAL;
 		break;
-	case pmac_low_i2c_mode_stdsub:
+	case pmac_i2c_mode_stdsub:
 		mode_reg |= KW_I2C_MODE_STANDARDSUB;
+		if (subsize != 1)
+			return -EINVAL;
 		break;
-	case pmac_low_i2c_mode_combined:
+	case pmac_i2c_mode_combined:
 		mode_reg |= KW_I2C_MODE_COMBINED;
+		if (subsize != 1)
+			return -EINVAL;
 		break;
 	}
 
 	/* Setup channel & clear pending irqs */
 	kw_write_reg(reg_isr, kw_read_reg(reg_isr));
-	kw_write_reg(reg_mode, mode_reg | (host->channel << 4));
+	kw_write_reg(reg_mode, mode_reg | (bus->channel << 4));
 	kw_write_reg(reg_status, 0);
 
-	/* Set up address and r/w bit */
-	kw_write_reg(reg_addr, addr);
+	/* Set up address and r/w bit, strip possible stale bus number from
+	 * address top bits
+	 */
+	kw_write_reg(reg_addr, addrdir & 0xff);
 
 	/* Set up the sub address */
 	if ((mode_reg & KW_I2C_MODE_MODE_MASK) == KW_I2C_MODE_STANDARDSUB
@@ -330,27 +375,27 @@ static int keywest_low_i2c_func(struct low_i2c_host *host, u8 addr, u8 subaddr,
 	kw_write_reg(reg_ier, 0 /*KW_I2C_IRQ_MASK*/);
 	kw_write_reg(reg_control, KW_I2C_CTL_XADDR);
 
-	/* State machine, to turn into an interrupt handler */
+	/* State machine, to turn into an interrupt handler in the future */
 	while(state != state_idle) {
-		u8 isr = kw_wait_interrupt(host);
-		state = kw_handle_interrupt(host, state, addr & 1, &rc, &data, &len, isr);
+		u8 isr = kw_i2c_wait_interrupt(bus);
+		state = kw_i2c_handle_interrupt(bus, state, addrdir & 1, &rc,
+						&data, &len, isr);
 	}
 
 	return rc;
 }
 
-static void keywest_low_i2c_add(struct device_node *np)
+static struct pmac_i2c_host_kw *__init kw_i2c_host_init(struct device_node *np)
 {
-	struct low_i2c_host	*host = find_low_i2c_host(NULL);
+	struct pmac_i2c_host_kw *host;
 	u32			*psteps, *prate, *addrp, steps;
-	struct device_node	*parent;
 
+	host = kzalloc(sizeof(struct pmac_i2c_host_kw), GFP_KERNEL);
 	if (host == NULL) {
 		printk(KERN_ERR "low_i2c: Can't allocate host for %s\n",
 		       np->full_name);
-		return;
+		return NULL;
 	}
-	memset(host, 0, sizeof(*host));
 
 	/* Apple is kind enough to provide a valid AAPL,address property
 	 * on all i2c keywest nodes so far ... we would have to fallback
@@ -360,18 +405,14 @@ static void keywest_low_i2c_add(struct device_node *np)
 	if (addrp == NULL) {
 		printk(KERN_ERR "low_i2c: Can't find address for %s\n",
 		       np->full_name);
-		return;
+		kfree(host);
+		return NULL;
 	}
 	init_MUTEX(&host->mutex);
-	host->np = of_node_get(np);	
 	psteps = (u32 *)get_property(np, "AAPL,address-step", NULL);
 	steps = psteps ? (*psteps) : 0x10;
 	for (host->bsteps = 0; (steps & 0x01) == 0; host->bsteps++)
 		steps >>= 1;
-	parent = of_get_parent(np);
-	host->num_channels = 1;
-	if (parent && parent->name[0] == 'u')
-		host->num_channels = 2;
 	/* Select interface rate */
 	host->speed = KW_I2C_MODE_25KHZ;
 	prate = (u32 *)get_property(np, "AAPL,i2c-rate", NULL);
@@ -387,148 +428,620 @@ static void keywest_low_i2c_add(struct device_node *np)
 		break;
 	}	
 
-	printk(KERN_INFO "low_i2c: Bus %s found at 0x%08x, %d channels,"
-	       " speed = %d KHz\n",
-	       np->full_name, *addrp, host->num_channels, prate ? *prate : 25);
-
-	host->mode = pmac_low_i2c_mode_std;
+	printk(KERN_INFO "KeyWest i2c @0x%08x %s\n", *addrp, np->full_name);
 	host->base = ioremap((*addrp), 0x1000);
-	host->func = keywest_low_i2c_func;
+
+	return host;
 }
 
+
+static void __init kw_i2c_add(struct pmac_i2c_host_kw *host,
+			      struct device_node *controller,
+			      struct device_node *busnode,
+			      int channel)
+{
+	struct pmac_i2c_bus *bus;
+
+	bus = kzalloc(sizeof(struct pmac_i2c_bus), GFP_KERNEL);
+	if (bus == NULL)
+		return;
+
+	bus->controller = of_node_get(controller);
+	bus->busnode = of_node_get(busnode);
+	bus->type = pmac_i2c_bus_keywest;
+	bus->hostdata = host;
+	bus->channel = channel;
+	bus->mode = pmac_i2c_mode_std;
+	bus->open = kw_i2c_open;
+	bus->close = kw_i2c_close;
+	bus->xfer = kw_i2c_xfer;
+	init_MUTEX(&bus->sem);
+	if (controller == busnode)
+		bus->flags = pmac_i2c_multibus;
+	list_add(&bus->link, &pmac_i2c_busses);
+
+	printk(KERN_INFO " channel %d bus %s\n", channel,
+	       (controller == busnode) ? "<multibus>" : busnode->full_name);
+}
+
+static void __init kw_i2c_probe(void)
+{
+	struct device_node *np, *child, *parent;
+
+	/* Probe keywest-i2c busses */
+	for (np = NULL;
+	     (np = of_find_compatible_node(np, "i2c","keywest-i2c")) != NULL;){
+		struct pmac_i2c_host_kw *host;
+		int multibus, chans, i;
+
+		/* Found one, init a host structure */
+		host = kw_i2c_host_init(np);
+		if (host == NULL)
+			continue;
+
+		/* Now check if we have a multibus setup (old style) or if we
+		 * have proper bus nodes. Note that the "new" way (proper bus
+		 * nodes) might cause us to not create some busses that are
+		 * kept hidden in the device-tree. In the future, we might
+		 * want to work around that by creating busses without a node
+		 * but not for now
+		 */
+		child = of_get_next_child(np, NULL);
+		multibus = !child || strcmp(child->name, "i2c-bus");
+		of_node_put(child);
+
+		/* For a multibus setup, we get the bus count based on the
+		 * parent type
+		 */
+		if (multibus) {
+			parent = of_get_parent(np);
+			if (parent == NULL)
+				continue;
+			chans = parent->name[0] == 'u' ? 2 : 1;
+			for (i = 0; i < chans; i++)
+				kw_i2c_add(host, np, np, i);
+		} else {
+			for (child = NULL;
+			     (child = of_get_next_child(np, child)) != NULL;) {
+				u32 *reg =
+					(u32 *)get_property(child, "reg", NULL);
+				if (reg == NULL)
+					continue;
+				kw_i2c_add(host, np, child, *reg);
+			}
+		}
+	}
+}
+
+
 /*
  *
  * PMU implementation
  *
  */
 
-
 #ifdef CONFIG_ADB_PMU
 
-static int pmu_low_i2c_func(struct low_i2c_host *host, u8 addr, u8 sub, u8 *data, int len)
+/*
+ * i2c command block to the PMU
+ */
+struct pmu_i2c_hdr {
+	u8	bus;
+	u8	mode;
+	u8	bus2;
+	u8	address;
+	u8	sub_addr;
+	u8	comb_addr;
+	u8	count;
+	u8	data[];
+};
+
+static void pmu_i2c_complete(struct adb_request *req)
 {
-	// TODO
-	return -ENODEV;
+	complete(req->arg);
 }
 
-static void pmu_low_i2c_add(struct device_node *np)
+static int pmu_i2c_xfer(struct pmac_i2c_bus *bus, u8 addrdir, int subsize,
+			u32 subaddr, u8 *data, int len)
 {
-	struct low_i2c_host	*host = find_low_i2c_host(NULL);
+	struct adb_request *req = bus->hostdata;
+	struct pmu_i2c_hdr *hdr = (struct pmu_i2c_hdr *)&req->data[1];
+	struct completion comp;
+	int read = addrdir & 1;
+	int retry;
+	int rc = 0;
 
-	if (host == NULL) {
-		printk(KERN_ERR "low_i2c: Can't allocate host for %s\n",
-		       np->full_name);
-		return;
+	/* For now, limit ourselves to 16 bytes transfers */
+	if (len > 16)
+		return -EINVAL;
+
+	init_completion(&comp);
+
+	for (retry = 0; retry < 16; retry++) {
+		memset(req, 0, sizeof(struct adb_request));
+		hdr->bus = bus->channel;
+		hdr->count = len;
+
+		switch(bus->mode) {
+		case pmac_i2c_mode_std:
+			if (subsize != 0)
+				return -EINVAL;
+			hdr->address = addrdir;
+			hdr->mode = PMU_I2C_MODE_SIMPLE;
+			break;
+		case pmac_i2c_mode_stdsub:
+		case pmac_i2c_mode_combined:
+			if (subsize != 1)
+				return -EINVAL;
+			hdr->address = addrdir & 0xfe;
+			hdr->comb_addr = addrdir;
+			hdr->sub_addr = subaddr;
+			if (bus->mode == pmac_i2c_mode_stdsub)
+				hdr->mode = PMU_I2C_MODE_STDSUB;
+			else
+				hdr->mode = PMU_I2C_MODE_COMBINED;
+			break;
+		default:
+			return -EINVAL;
+		}
+
+		INIT_COMPLETION(comp);
+		req->data[0] = PMU_I2C_CMD;
+		req->reply[0] = 0xff;
+		req->nbytes = sizeof(struct pmu_i2c_hdr) + 1;
+		req->done = pmu_i2c_complete;
+		req->arg = &comp;
+		if (!read) {
+			memcpy(hdr->data, data, len);
+			req->nbytes += len;
+		}
+		rc = pmu_queue_request(req);
+		if (rc)
+			return rc;
+		wait_for_completion(&comp);
+		if (req->reply[0] == PMU_I2C_STATUS_OK)
+			break;
+		msleep(15);
 	}
-	memset(host, 0, sizeof(*host));
+	if (req->reply[0] != PMU_I2C_STATUS_OK)
+		return -EIO;
 
-	init_MUTEX(&host->mutex);
-	host->np = of_node_get(np);	
-	host->num_channels = 3;
-	host->mode = pmac_low_i2c_mode_std;
-	host->func = pmu_low_i2c_func;
+	for (retry = 0; retry < 16; retry++) {
+		memset(req, 0, sizeof(struct adb_request));
+
+		/* I know that looks like a lot, slow as hell, but darwin
+		 * does it so let's be on the safe side for now
+		 */
+		msleep(15);
+
+		hdr->bus = PMU_I2C_BUS_STATUS;
+
+		INIT_COMPLETION(comp);
+		req->data[0] = PMU_I2C_CMD;
+		req->reply[0] = 0xff;
+		req->nbytes = 2;
+		req->done = pmu_i2c_complete;
+		req->arg = &comp;
+		rc = pmu_queue_request(req);
+		if (rc)
+			return rc;
+		wait_for_completion(&comp);
+
+		if (req->reply[0] == PMU_I2C_STATUS_OK && !read)
+			return 0;
+		if (req->reply[0] == PMU_I2C_STATUS_DATAREAD && read) {
+			int rlen = req->reply_len - 1;
+
+			if (rlen != len) {
+				printk(KERN_WARNING "low_i2c: PMU returned %d"
+				       " bytes, expected %d !\n", rlen, len);
+				return -EIO;
+			}
+			memcpy(data, &req->reply[1], len);
+			return 0;
+		}
+	}
+	return -EIO;
+}
+
+static void __init pmu_i2c_probe(void)
+{
+	struct pmac_i2c_bus *bus;
+	struct device_node *busnode;
+	int channel, sz;
+
+	if (!pmu_present())
+		return;
+
+	/* There might or might not be a "pmu-i2c" node, we use that
+	 * or via-pmu itself, whatever we find. I haven't seen a machine
+	 * with separate bus nodes, so we assume a multibus setup
+	 */
+	busnode = of_find_node_by_name(NULL, "pmu-i2c");
+	if (busnode == NULL)
+		busnode = of_find_node_by_name(NULL, "via-pmu");
+	if (busnode == NULL)
+		return;
+
+	printk(KERN_INFO "PMU i2c %s\n", busnode->full_name);
+
+	/*
+	 * We add bus 1 and 2 only for now, bus 0 is "special"
+	 */
+	for (channel = 1; channel <= 2; channel++) {
+		sz = sizeof(struct pmac_i2c_bus) + sizeof(struct adb_request);
+		bus = kzalloc(sz, GFP_KERNEL);
+		if (bus == NULL)
+			return;
+
+		bus->controller = busnode;
+		bus->busnode = busnode;
+		bus->type = pmac_i2c_bus_pmu;
+		bus->channel = channel;
+		bus->mode = pmac_i2c_mode_std;
+		bus->hostdata = bus + 1;
+		bus->xfer = pmu_i2c_xfer;
+		init_MUTEX(&bus->sem);
+		bus->flags = pmac_i2c_multibus;
+		list_add(&bus->link, &pmac_i2c_busses);
+
+		printk(KERN_INFO " channel %d bus <multibus>\n", channel);
+	}
 }
 
 #endif /* CONFIG_ADB_PMU */
 
-void __init pmac_init_low_i2c(void)
+
+/*
+ *
+ * SMU implementation
+ *
+ */
+
+#ifdef CONFIG_PMAC_SMU
+
+static void smu_i2c_complete(struct smu_i2c_cmd *cmd, void *misc)
 {
-	struct device_node *np;
+	complete(misc);
+}
 
-	/* Probe keywest-i2c busses */
-	np = of_find_compatible_node(NULL, "i2c", "keywest-i2c");
-	while(np) {
-		keywest_low_i2c_add(np);
-		np = of_find_compatible_node(np, "i2c", "keywest-i2c");
+static int smu_i2c_xfer(struct pmac_i2c_bus *bus, u8 addrdir, int subsize,
+			u32 subaddr, u8 *data, int len)
+{
+	struct smu_i2c_cmd *cmd = bus->hostdata;
+	struct completion comp;
+	int read = addrdir & 1;
+	int rc = 0;
+
+	memset(cmd, 0, sizeof(struct smu_i2c_cmd));
+	cmd->info.bus = bus->channel;
+	cmd->info.devaddr = addrdir;
+	cmd->info.datalen = len;
+
+	switch(bus->mode) {
+	case pmac_i2c_mode_std:
+		if (subsize != 0)
+			return -EINVAL;
+		cmd->info.type = SMU_I2C_TRANSFER_SIMPLE;
+		break;
+	case pmac_i2c_mode_stdsub:
+	case pmac_i2c_mode_combined:
+		if (subsize > 3 || subsize < 1)
+			return -EINVAL;
+		cmd->info.sublen = subsize;
+		/* that's big-endian only but heh ! */
+		memcpy(&cmd->info.subaddr, ((char *)&subaddr) + (4 - subsize),
+		       subsize);
+		if (bus->mode == pmac_i2c_mode_stdsub)
+			cmd->info.type = SMU_I2C_TRANSFER_STDSUB;
+		else
+			cmd->info.type = SMU_I2C_TRANSFER_COMBINED;
+		break;
+	default:
+		return -EINVAL;
 	}
+	if (!read)
+		memcpy(cmd->info.data, data, len);
+
+	init_completion(&comp);
+	cmd->done = smu_i2c_complete;
+	cmd->misc = &comp;
+	rc = smu_queue_i2c(cmd);
+	if (rc < 0)
+		return rc;
+	wait_for_completion(&comp);
+	rc = cmd->status;
+
+	if (read)
+		memcpy(data, cmd->info.data, len);
+	return rc < 0 ? rc : 0;
+}
 
-#ifdef CONFIG_ADB_PMU
-	/* Probe PMU busses */
-	np = of_find_node_by_name(NULL, "via-pmu");
-	if (np)
-		pmu_low_i2c_add(np);
-#endif /* CONFIG_ADB_PMU */
+static void __init smu_i2c_probe(void)
+{
+	struct device_node *controller, *busnode;
+	struct pmac_i2c_bus *bus;
+	u32 *reg;
+	int sz;
+
+	if (!smu_present())
+		return;
+
+	controller = of_find_node_by_name(NULL, "smu_i2c_control");
+	if (controller == NULL)
+		controller = of_find_node_by_name(NULL, "smu");
+	if (controller == NULL)
+		return;
+
+	printk(KERN_INFO "SMU i2c %s\n", controller->full_name);
+
+	/* Look for childs, note that they might not be of the right
+	 * type as older device trees mix i2c busses and other thigns
+	 * at the same level
+	 */
+	for (busnode = NULL;
+	     (busnode = of_get_next_child(controller, busnode)) != NULL;) {
+		if (strcmp(busnode->type, "i2c") &&
+		    strcmp(busnode->type, "i2c-bus"))
+			continue;
+		reg = (u32 *)get_property(busnode, "reg", NULL);
+		if (reg == NULL)
+			continue;
+
+		sz = sizeof(struct pmac_i2c_bus) + sizeof(struct smu_i2c_cmd);
+		bus = kzalloc(sz, GFP_KERNEL);
+		if (bus == NULL)
+			return;
+
+		bus->controller = controller;
+		bus->busnode = of_node_get(busnode);
+		bus->type = pmac_i2c_bus_smu;
+		bus->channel = *reg;
+		bus->mode = pmac_i2c_mode_std;
+		bus->hostdata = bus + 1;
+		bus->xfer = smu_i2c_xfer;
+		init_MUTEX(&bus->sem);
+		bus->flags = 0;
+		list_add(&bus->link, &pmac_i2c_busses);
+
+		printk(KERN_INFO " channel %x bus %s\n",
+		       bus->channel, busnode->full_name);
+	}
+}
+
+#endif /* CONFIG_PMAC_SMU */
+
+/*
+ *
+ * Core code
+ *
+ */
+
+
+struct pmac_i2c_bus *pmac_i2c_find_bus(struct device_node *node)
+{
+	struct device_node *p = of_node_get(node);
+	struct device_node *prev = NULL;
+	struct pmac_i2c_bus *bus;
+
+	while(p) {
+		list_for_each_entry(bus, &pmac_i2c_busses, link) {
+			if (p == bus->busnode) {
+				if (prev && bus->flags & pmac_i2c_multibus) {
+					u32 *reg;
+					reg = (u32 *)get_property(prev, "reg",
+								  NULL);
+					if (!reg)
+						continue;
+					if (((*reg) >> 8) != bus->channel)
+						continue;
+				}
+				of_node_put(p);
+				of_node_put(prev);
+				return bus;
+			}
+		}
+		of_node_put(prev);
+		prev = p;
+		p = of_get_parent(p);
+	}
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(pmac_i2c_find_bus);
+
+u8 pmac_i2c_get_dev_addr(struct device_node *device)
+{
+	u32 *reg = (u32 *)get_property(device, "reg", NULL);
+
+	if (reg == NULL)
+		return 0;
+
+	return (*reg) & 0xff;
+}
+EXPORT_SYMBOL_GPL(pmac_i2c_get_dev_addr);
+
+struct device_node *pmac_i2c_get_controller(struct pmac_i2c_bus *bus)
+{
+	return bus->controller;
+}
+EXPORT_SYMBOL_GPL(pmac_i2c_get_controller);
+
+struct device_node *pmac_i2c_get_bus_node(struct pmac_i2c_bus *bus)
+{
+	return bus->busnode;
+}
+EXPORT_SYMBOL_GPL(pmac_i2c_get_bus_node);
+
+int pmac_i2c_get_type(struct pmac_i2c_bus *bus)
+{
+	return bus->type;
+}
+EXPORT_SYMBOL_GPL(pmac_i2c_get_type);
+
+int pmac_i2c_get_flags(struct pmac_i2c_bus *bus)
+{
+	return bus->flags;
+}
+EXPORT_SYMBOL_GPL(pmac_i2c_get_flags);
 
-	/* TODO: Add CUDA support as well */
+void pmac_i2c_attach_adapter(struct pmac_i2c_bus *bus,
+			     struct i2c_adapter *adapter)
+{
+	WARN_ON(bus->adapter != NULL);
+	bus->adapter = adapter;
 }
+EXPORT_SYMBOL_GPL(pmac_i2c_attach_adapter);
+
+void pmac_i2c_detach_adapter(struct pmac_i2c_bus *bus,
+			     struct i2c_adapter *adapter)
+{
+	WARN_ON(bus->adapter != adapter);
+	bus->adapter = NULL;
+}
+EXPORT_SYMBOL_GPL(pmac_i2c_detach_adapter);
+
+struct i2c_adapter *pmac_i2c_get_adapter(struct pmac_i2c_bus *bus)
+{
+	return bus->adapter;
+}
+EXPORT_SYMBOL_GPL(pmac_i2c_get_adapter);
+
+extern int pmac_i2c_match_adapter(struct device_node *dev,
+				  struct i2c_adapter *adapter)
+{
+	struct pmac_i2c_bus *bus = pmac_i2c_find_bus(dev);
+
+	if (bus == NULL)
+		return 0;
+	return (bus->adapter == adapter);
+}
+EXPORT_SYMBOL_GPL(pmac_i2c_match_adapter);
 
 int pmac_low_i2c_lock(struct device_node *np)
 {
-	struct low_i2c_host *host = find_low_i2c_host(np);
+	struct pmac_i2c_bus *bus, *found = NULL;
 
-	if (!host)
+	list_for_each_entry(bus, &pmac_i2c_busses, link) {
+		if (np == bus->controller) {
+			found = bus;
+			break;
+		}
+	}
+	if (!found)
 		return -ENODEV;
-	down(&host->mutex);
-	return 0;
+	return pmac_i2c_open(bus, 0);
 }
-EXPORT_SYMBOL(pmac_low_i2c_lock);
+EXPORT_SYMBOL_GPL(pmac_low_i2c_lock);
 
 int pmac_low_i2c_unlock(struct device_node *np)
 {
-	struct low_i2c_host *host = find_low_i2c_host(np);
+	struct pmac_i2c_bus *bus, *found = NULL;
 
-	if (!host)
+	list_for_each_entry(bus, &pmac_i2c_busses, link) {
+		if (np == bus->controller) {
+			found = bus;
+			break;
+		}
+	}
+	if (!found)
 		return -ENODEV;
-	up(&host->mutex);
+	pmac_i2c_close(bus);
 	return 0;
 }
-EXPORT_SYMBOL(pmac_low_i2c_unlock);
+EXPORT_SYMBOL_GPL(pmac_low_i2c_unlock);
 
 
-int pmac_low_i2c_open(struct device_node *np, int channel)
+int pmac_i2c_open(struct pmac_i2c_bus *bus, int polled)
 {
-	struct low_i2c_host *host = find_low_i2c_host(np);
+	int rc;
+
+	down(&bus->sem);
+	bus->polled = polled;
+	bus->opened = 1;
+	bus->mode = pmac_i2c_mode_std;
+	if (bus->open && (rc = bus->open(bus)) != 0) {
+		bus->opened = 0;
+		up(&bus->sem);
+		return rc;
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(pmac_i2c_open);
 
-	if (!host)
-		return -ENODEV;
+void pmac_i2c_close(struct pmac_i2c_bus *bus)
+{
+	WARN_ON(!bus->opened);
+	if (bus->close)
+		bus->close(bus);
+	bus->opened = 0;
+	up(&bus->sem);
+}
+EXPORT_SYMBOL_GPL(pmac_i2c_close);
 
-	if (channel >= host->num_channels)
-		return -EINVAL;
+int pmac_i2c_setmode(struct pmac_i2c_bus *bus, int mode)
+{
+	WARN_ON(!bus->opened);
 
-	down(&host->mutex);
-	host->is_open = 1;
-	host->channel = channel;
+	/* Report me if you see the error below as there might be a new
+	 * "combined4" mode that I need to implement for the SMU bus
+	 */
+	if (mode < pmac_i2c_mode_dumb || mode > pmac_i2c_mode_combined) {
+		printk(KERN_ERR "low_i2c: Invalid mode %d requested on"
+		       " bus %s !\n", mode, bus->busnode->full_name);
+		return -EINVAL;
+	}
+	bus->mode = mode;
 
 	return 0;
 }
-EXPORT_SYMBOL(pmac_low_i2c_open);
+EXPORT_SYMBOL_GPL(pmac_i2c_setmode);
 
-int pmac_low_i2c_close(struct device_node *np)
+int pmac_i2c_xfer(struct pmac_i2c_bus *bus, u8 addrdir, int subsize,
+		  u32 subaddr, u8 *data, int len)
 {
-	struct low_i2c_host *host = find_low_i2c_host(np);
+	int rc;
 
-	if (!host)
-		return -ENODEV;
+	WARN_ON(!bus->opened);
 
-	host->is_open = 0;
-	up(&host->mutex);
+	DBG("xfer() chan=%d, addrdir=0x%x, mode=%d, subsize=%d, subaddr=0x%x,"
+	    " %d bytes, bus %s\n", bus->channel, addrdir, bus->mode, subsize,
+	    subaddr, len, bus->busnode->full_name);
 
-	return 0;
+	rc = bus->xfer(bus, addrdir, subsize, subaddr, data, len);
+
+#ifdef DEBUG
+	if (rc)
+		DBG("xfer error %d\n", rc);
+#endif
+	return rc;
 }
-EXPORT_SYMBOL(pmac_low_i2c_close);
+EXPORT_SYMBOL_GPL(pmac_i2c_xfer);
 
-int pmac_low_i2c_setmode(struct device_node *np, int mode)
+/*
+ * Initialize us: probe all i2c busses on the machine and instantiate
+ * busses.
+ */
+/* This is non-static as it might be called early by smp code */
+int __init pmac_i2c_init(void)
 {
-	struct low_i2c_host *host = find_low_i2c_host(np);
+	static int i2c_inited;
 
-	if (!host)
-		return -ENODEV;
-	WARN_ON(!host->is_open);
-	host->mode = mode;
+	if (i2c_inited)
+		return 0;
+	i2c_inited = 1;
 
-	return 0;
-}
-EXPORT_SYMBOL(pmac_low_i2c_setmode);
+	/* Probe keywest-i2c busses */
+	kw_i2c_probe();
 
-int pmac_low_i2c_xfer(struct device_node *np, u8 addrdir, u8 subaddr, u8 *data, int len)
-{
-	struct low_i2c_host *host = find_low_i2c_host(np);
+#ifdef CONFIG_ADB_PMU
+	pmu_i2c_probe();
+#endif
 
-	if (!host)
-		return -ENODEV;
-	WARN_ON(!host->is_open);
+#ifdef CONFIG_PMAC_SMU
+	smu_i2c_probe();
+#endif
 
-	return host->func(host, addrdir, subaddr, data, len);
+	return 0;
 }
-EXPORT_SYMBOL(pmac_low_i2c_xfer);
+arch_initcall(pmac_i2c_init);
 
diff --git a/arch/powerpc/platforms/powermac/setup.c b/arch/powerpc/platforms/powermac/setup.c
index e5a5bdbdda7..dc5cdc1484e 100644
--- a/arch/powerpc/platforms/powermac/setup.c
+++ b/arch/powerpc/platforms/powermac/setup.c
@@ -652,27 +652,22 @@ static int __init pmac_declare_of_platform_devices(void)
 {
 	struct device_node *np, *npp;
 
-	np = find_devices("uni-n");
-	if (np) {
-		for (np = np->child; np != NULL; np = np->sibling)
-			if (strncmp(np->name, "i2c", 3) == 0) {
-				of_platform_device_create(np, "uni-n-i2c",
-							  NULL);
-				break;
-			}
-	}
-	np = find_devices("valkyrie");
+	np = of_find_node_by_name(NULL, "valkyrie");
 	if (np)
 		of_platform_device_create(np, "valkyrie", NULL);
-	np = find_devices("platinum");
+	np = of_find_node_by_name(NULL, "platinum");
 	if (np)
 		of_platform_device_create(np, "platinum", NULL);
-
-	npp = of_find_node_by_name(NULL, "u3");
+	npp = of_find_node_by_name(NULL, "uni-n");
+	if (npp == NULL)
+		npp = of_find_node_by_name(NULL, "u3");
+	if (npp == NULL)
+		npp = of_find_node_by_name(NULL, "u4");
 	if (npp) {
 		for (np = NULL; (np = of_get_next_child(npp, np)) != NULL;) {
 			if (strncmp(np->name, "i2c", 3) == 0) {
-				of_platform_device_create(np, "u3-i2c", NULL);
+				of_platform_device_create(np, "uni-n-i2c",
+							  NULL);
 				of_node_put(np);
 				break;
 			}
diff --git a/arch/powerpc/platforms/powermac/smp.c b/arch/powerpc/platforms/powermac/smp.c
index df01bb8feb1..ab72ba86be1 100644
--- a/arch/powerpc/platforms/powermac/smp.c
+++ b/arch/powerpc/platforms/powermac/smp.c
@@ -482,7 +482,7 @@ static void __devinit smp_core99_take_timebase(void)
 /*
  * G5s enable/disable the timebase via an i2c-connected clock chip.
  */
-static struct device_node *pmac_tb_clock_chip_host;
+static struct pmac_i2c_bus *pmac_tb_clock_chip_host;
 static u8 pmac_tb_pulsar_addr;
 
 static void smp_core99_cypress_tb_freeze(int freeze)
@@ -493,20 +493,20 @@ static void smp_core99_cypress_tb_freeze(int freeze)
 	/* Strangely, the device-tree says address is 0xd2, but darwin
 	 * accesses 0xd0 ...
 	 */
-	pmac_low_i2c_setmode(pmac_tb_clock_chip_host,
-			     pmac_low_i2c_mode_combined);
-	rc = pmac_low_i2c_xfer(pmac_tb_clock_chip_host,
-			       0xd0 | pmac_low_i2c_read,
-			       0x81, &data, 1);
+	pmac_i2c_setmode(pmac_tb_clock_chip_host,
+			 pmac_i2c_mode_combined);
+	rc = pmac_i2c_xfer(pmac_tb_clock_chip_host,
+			   0xd0 | pmac_i2c_read,
+			   1, 0x81, &data, 1);
 	if (rc != 0)
 		goto bail;
 
 	data = (data & 0xf3) | (freeze ? 0x00 : 0x0c);
 
-       	pmac_low_i2c_setmode(pmac_tb_clock_chip_host, pmac_low_i2c_mode_stdsub);
-	rc = pmac_low_i2c_xfer(pmac_tb_clock_chip_host,
-			       0xd0 | pmac_low_i2c_write,
-			       0x81, &data, 1);
+       	pmac_i2c_setmode(pmac_tb_clock_chip_host, pmac_i2c_mode_stdsub);
+	rc = pmac_i2c_xfer(pmac_tb_clock_chip_host,
+			   0xd0 | pmac_i2c_write,
+			   1, 0x81, &data, 1);
 
  bail:
 	if (rc != 0) {
@@ -522,20 +522,20 @@ static void smp_core99_pulsar_tb_freeze(int freeze)
 	u8 data;
 	int rc;
 
-	pmac_low_i2c_setmode(pmac_tb_clock_chip_host,
-			     pmac_low_i2c_mode_combined);
-	rc = pmac_low_i2c_xfer(pmac_tb_clock_chip_host,
-			       pmac_tb_pulsar_addr | pmac_low_i2c_read,
-			       0x2e, &data, 1);
+	pmac_i2c_setmode(pmac_tb_clock_chip_host,
+			 pmac_i2c_mode_combined);
+	rc = pmac_i2c_xfer(pmac_tb_clock_chip_host,
+			   pmac_tb_pulsar_addr | pmac_i2c_read,
+			   1, 0x2e, &data, 1);
 	if (rc != 0)
 		goto bail;
 
 	data = (data & 0x88) | (freeze ? 0x11 : 0x22);
 
-	pmac_low_i2c_setmode(pmac_tb_clock_chip_host, pmac_low_i2c_mode_stdsub);
-	rc = pmac_low_i2c_xfer(pmac_tb_clock_chip_host,
-			       pmac_tb_pulsar_addr | pmac_low_i2c_write,
-			       0x2e, &data, 1);
+	pmac_i2c_setmode(pmac_tb_clock_chip_host, pmac_i2c_mode_stdsub);
+	rc = pmac_i2c_xfer(pmac_tb_clock_chip_host,
+			   pmac_tb_pulsar_addr | pmac_i2c_write,
+			   1, 0x2e, &data, 1);
  bail:
 	if (rc != 0) {
 		printk(KERN_ERR "Pulsar Timebase %s rc: %d\n",
@@ -560,13 +560,15 @@ static void __init smp_core99_setup_i2c_hwsync(int ncpus)
 		if (!ok)
 			continue;
 
+		pmac_tb_clock_chip_host = pmac_i2c_find_bus(cc);
+		if (pmac_tb_clock_chip_host == NULL)
+			continue;
 		reg = (u32 *)get_property(cc, "reg", NULL);
 		if (reg == NULL)
 			continue;
-
 		switch (*reg) {
 		case 0xd2:
-			if (device_is_compatible(cc, "pulsar-legacy-slewing")) {
+			if (device_is_compatible(cc,"pulsar-legacy-slewing")) {
 				pmac_tb_freeze = smp_core99_pulsar_tb_freeze;
 				pmac_tb_pulsar_addr = 0xd2;
 				name = "Pulsar";
@@ -585,30 +587,19 @@ static void __init smp_core99_setup_i2c_hwsync(int ncpus)
 			break;
 	}
 	if (pmac_tb_freeze != NULL) {
-		struct device_node *p = of_get_parent(cc);
-		of_node_put(cc);
-		while(p && strcmp(p->type, "i2c")) {
-			cc = of_get_parent(p);
-			of_node_put(p);
-			p = cc;
-		}
-		if (p == NULL)
-			goto no_i2c_sync;
 		/* Open i2c bus for synchronous access */
-		if (pmac_low_i2c_open(p, 0)) {
-			printk(KERN_ERR "Failed top open i2c bus %s for clock"
-			       " sync, fallback to software sync !\n",
-			       p->full_name);
-			of_node_put(p);
+		if (pmac_i2c_open(pmac_tb_clock_chip_host, 1)) {
+			printk(KERN_ERR "Failed top open i2c bus for clock"
+			       " sync, fallback to software sync !\n");
 			goto no_i2c_sync;
 		}
-		pmac_tb_clock_chip_host = p;
 		printk(KERN_INFO "Processor timebase sync using %s i2c clock\n",
 		       name);
 		return;
 	}
  no_i2c_sync:
 	pmac_tb_freeze = NULL;
+	pmac_tb_clock_chip_host = NULL;
 }
 
 #endif /* CONFIG_PPC64 */
@@ -752,8 +743,18 @@ static int __init smp_core99_probe(void)
 	if (ncpus <= 1)
 		return 1;
 
+	/* We need to perform some early initialisations before we can start
+	 * setting up SMP as we are running before initcalls
+	 */
+	pmac_i2c_init();
+
+	/* Setup various bits like timebase sync method, ability to nap, ... */
 	smp_core99_setup(ncpus);
+
+	/* Install IPIs */
 	mpic_request_ipis();
+
+	/* Collect l2cr and l3cr values from CPU 0 */
 	core99_init_caches(0);
 
 	return ncpus;
@@ -817,7 +818,7 @@ static void __devinit smp_core99_setup_cpu(int cpu_nr)
 
 		/* Close i2c bus if it was used for tb sync */
 		if (pmac_tb_clock_chip_host) {
-			pmac_low_i2c_close(pmac_tb_clock_chip_host);
+			pmac_i2c_close(pmac_tb_clock_chip_host);
 			pmac_tb_clock_chip_host	= NULL;
 		}