diff --git a/drivers/macintosh/therm_windtunnel.c b/drivers/macintosh/therm_windtunnel.c
new file mode 100644
index 0000000..c153699
--- /dev/null
+++ b/drivers/macintosh/therm_windtunnel.c
@@ -0,0 +1,531 @@
+/* 
+ *   Creation Date: <2003/03/14 20:54:13 samuel>
+ *   Time-stamp: <2004/03/20 14:20:59 samuel>
+ *   
+ *	<therm_windtunnel.c>
+ *	
+ *	The G4 "windtunnel" has a single fan controlled by an
+ *	ADM1030 fan controller and a DS1775 thermostat.
+ *
+ *	The fan controller is equipped with a temperature sensor
+ *	which measures the case temperature. The DS1775 sensor
+ *	measures the CPU temperature. This driver tunes the
+ *	behavior of the fan. It is based upon empirical observations
+ *	of the 'AppleFan' driver under Mac OS X.
+ *
+ *	WARNING: This driver has only been testen on Apple's
+ *	1.25 MHz Dual G4 (March 03). It is tuned for a CPU
+ *	temperatur around 57 C.
+ *
+ *   Copyright (C) 2003, 2004 Samuel Rydh (samuel@ibrium.se)
+ *
+ *   Loosely based upon 'thermostat.c' written by Benjamin Herrenschmidt
+ *   
+ *   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
+ *   
+ */
+
+#include <linux/config.h>
+#include <linux/types.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/sched.h>
+#include <linux/i2c.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <asm/prom.h>
+#include <asm/machdep.h>
+#include <asm/io.h>
+#include <asm/system.h>
+#include <asm/sections.h>
+#include <asm/of_device.h>
+
+#define LOG_TEMP		0			/* continously log temperature */
+
+#define I2C_DRIVERID_G4FAN	0x9001			/* fixme */
+
+static int 			do_probe( struct i2c_adapter *adapter, int addr, int kind);
+
+/* scan 0x48-0x4f (DS1775) and 0x2c-2x2f (ADM1030) */
+static unsigned short		normal_i2c[] = { 0x49, 0x2c, I2C_CLIENT_END };
+static unsigned short		normal_i2c_range[] = { 0x48, 0x4f, 0x2c, 0x2f, I2C_CLIENT_END };
+
+I2C_CLIENT_INSMOD;
+
+static struct {
+	volatile int		running;
+	struct completion	completion;
+	pid_t			poll_task;
+	
+	struct semaphore 	lock;
+	struct of_device	*of_dev;
+	
+	struct i2c_client	*thermostat;
+	struct i2c_client	*fan;
+
+	int			overheat_temp;		/* 100% fan at this temp */
+	int			overheat_hyst;
+	int			temp;
+	int			casetemp;
+	int			fan_level;		/* active fan_table setting */
+
+	int			downind;
+	int			upind;
+
+	int			r0, r1, r20, r23, r25;	/* saved register */
+} x;
+
+#define T(x,y)			(((x)<<8) | (y)*0x100/10 )
+
+static struct {
+	int			fan_down_setting;
+	int			temp;
+	int			fan_up_setting;
+} fan_table[] = {
+	{ 11, T(0,0),  11 },	/* min fan */
+	{ 11, T(55,0), 11 },
+	{  6, T(55,3), 11 },
+	{  7, T(56,0), 11 },
+	{  8, T(57,0), 8 },
+	{  7, T(58,3), 7 },
+	{  6, T(58,8), 6 },
+	{  5, T(59,2), 5 },
+	{  4, T(59,6), 4 },
+	{  3, T(59,9), 3 },
+	{  2, T(60,1), 2 },
+	{  1, 0xfffff, 1 }	/* on fire */
+};
+
+static void
+print_temp( const char *s, int temp )
+{
+	printk("%s%d.%d C", s ? s : "", temp>>8, (temp & 255)*10/256 );
+}
+
+static ssize_t
+show_cpu_temperature( struct device *dev, char *buf )
+{
+	return sprintf(buf, "%d.%d\n", x.temp>>8, (x.temp & 255)*10/256 );
+}
+
+static ssize_t
+show_case_temperature( struct device *dev, char *buf )
+{
+	return sprintf(buf, "%d.%d\n", x.casetemp>>8, (x.casetemp & 255)*10/256 );
+}
+
+static DEVICE_ATTR(cpu_temperature, S_IRUGO, show_cpu_temperature, NULL );
+static DEVICE_ATTR(case_temperature, S_IRUGO, show_case_temperature, NULL );
+
+
+
+/************************************************************************/
+/*	controller thread						*/
+/************************************************************************/
+
+static int
+write_reg( struct i2c_client *cl, int reg, int data, int len )
+{
+	u8 tmp[3];
+
+	if( len < 1 || len > 2 || data < 0 )
+		return -EINVAL;
+
+	tmp[0] = reg;
+	tmp[1] = (len == 1) ? data : (data >> 8);
+	tmp[2] = data;
+	len++;
+	
+	if( i2c_master_send(cl, tmp, len) != len )
+		return -ENODEV;
+	return 0;
+}
+
+static int
+read_reg( struct i2c_client *cl, int reg, int len )
+{
+	u8 buf[2];
+
+	if( len != 1 && len != 2 )
+		return -EINVAL;
+	buf[0] = reg;
+	if( i2c_master_send(cl, buf, 1) != 1 )
+		return -ENODEV;
+	if( i2c_master_recv(cl, buf, len) != len )
+		return -ENODEV;
+	return (len == 2)? ((unsigned int)buf[0] << 8) | buf[1] : buf[0];
+}
+
+static void
+tune_fan( int fan_setting )
+{
+	int val = (fan_setting << 3) | 7;
+
+	/* write_reg( x.fan, 0x24, val, 1 ); */
+	write_reg( x.fan, 0x25, val, 1 );
+	write_reg( x.fan, 0x20, 0, 1 );
+	print_temp("CPU-temp: ", x.temp );
+	if( x.casetemp )
+		print_temp(", Case: ", x.casetemp );
+	printk(",  Fan: %d (tuned %+d)\n", 11-fan_setting, x.fan_level-fan_setting );
+
+	x.fan_level = fan_setting;
+}
+
+static void
+poll_temp( void )
+{
+	int temp, i, level, casetemp;
+
+	temp = read_reg( x.thermostat, 0, 2 );
+
+	/* this actually occurs when the computer is loaded */
+	if( temp < 0 )
+		return;
+
+	casetemp = read_reg(x.fan, 0x0b, 1) << 8;
+	casetemp |= (read_reg(x.fan, 0x06, 1) & 0x7) << 5;
+
+	if( LOG_TEMP && x.temp != temp ) {
+		print_temp("CPU-temp: ", temp );
+		print_temp(", Case: ", casetemp );
+		printk(",  Fan: %d\n", 11-x.fan_level );
+	}
+	x.temp = temp;
+	x.casetemp = casetemp;
+
+	level = -1;
+	for( i=0; (temp & 0xffff) > fan_table[i].temp ; i++ )
+		;
+	if( i < x.downind )
+		level = fan_table[i].fan_down_setting;
+	x.downind = i;
+
+	for( i=0; (temp & 0xffff) >= fan_table[i+1].temp ; i++ )
+		;
+	if( x.upind < i )
+		level = fan_table[i].fan_up_setting;
+	x.upind = i;
+
+	if( level >= 0 )
+		tune_fan( level );
+}
+
+
+static void
+setup_hardware( void )
+{
+	int val;
+
+	/* save registers (if we unload the module) */
+	x.r0 = read_reg( x.fan, 0x00, 1 );
+	x.r1 = read_reg( x.fan, 0x01, 1 );
+	x.r20 = read_reg( x.fan, 0x20, 1 );
+	x.r23 = read_reg( x.fan, 0x23, 1 );
+	x.r25 = read_reg( x.fan, 0x25, 1 );
+
+	/* improve measurement resolution (convergence time 1.5s) */
+	if( (val=read_reg(x.thermostat, 1, 1)) >= 0 ) {
+		val |= 0x60;
+		if( write_reg( x.thermostat, 1, val, 1 ) )
+			printk("Failed writing config register\n");
+	}
+	/* disable interrupts and TAC input */
+	write_reg( x.fan, 0x01, 0x01, 1 );
+	/* enable filter */
+	write_reg( x.fan, 0x23, 0x91, 1 );
+	/* remote temp. controls fan */
+	write_reg( x.fan, 0x00, 0x95, 1 );
+
+	/* The thermostat (which besides measureing temperature controls
+	 * has a THERM output which puts the fan on 100%) is usually
+	 * set to kick in at 80 C (chip default). We reduce this a bit
+	 * to be on the safe side (OSX doesn't)...
+	 */
+	if( x.overheat_temp == (80 << 8) ) {
+		x.overheat_temp = 65 << 8;
+		x.overheat_hyst = 60 << 8;
+		write_reg( x.thermostat, 2, x.overheat_hyst, 2 );
+		write_reg( x.thermostat, 3, x.overheat_temp, 2 );
+
+		print_temp("Reducing overheating limit to ", x.overheat_temp );
+		print_temp(" (Hyst: ", x.overheat_hyst );
+		printk(")\n");
+	}
+
+	/* set an initial fan setting */
+	x.downind = 0xffff;
+	x.upind = -1;
+	/* tune_fan( fan_up_table[x.upind].fan_setting ); */
+
+	device_create_file( &x.of_dev->dev, &dev_attr_cpu_temperature );
+	device_create_file( &x.of_dev->dev, &dev_attr_case_temperature );
+}
+
+static void
+restore_regs( void )
+{
+	device_remove_file( &x.of_dev->dev, &dev_attr_cpu_temperature );
+	device_remove_file( &x.of_dev->dev, &dev_attr_case_temperature );
+
+	write_reg( x.fan, 0x01, x.r1, 1 );
+	write_reg( x.fan, 0x20, x.r20, 1 );
+	write_reg( x.fan, 0x23, x.r23, 1 );
+	write_reg( x.fan, 0x25, x.r25, 1 );
+	write_reg( x.fan, 0x00, x.r0, 1 );
+}
+
+static int
+control_loop( void *dummy )
+{
+	daemonize("g4fand");
+
+	down( &x.lock );
+	setup_hardware();
+
+	while( x.running ) {
+		up( &x.lock );
+
+		msleep_interruptible(8000);
+		
+		down( &x.lock );
+		poll_temp();
+	}
+
+	restore_regs();
+	up( &x.lock );
+
+	complete_and_exit( &x.completion, 0 );
+}
+
+
+/************************************************************************/
+/*	i2c probing and setup						*/
+/************************************************************************/
+
+static int
+do_attach( struct i2c_adapter *adapter )
+{
+	int ret = 0;
+
+	if( strncmp(adapter->name, "uni-n", 5) )
+		return 0;
+
+	if( !x.running ) {
+		ret = i2c_probe( adapter, &addr_data, &do_probe );
+		if( x.thermostat && x.fan ) {
+			x.running = 1;
+			init_completion( &x.completion );
+			x.poll_task = kernel_thread( control_loop, NULL, SIGCHLD | CLONE_KERNEL );
+		}
+	}
+	return ret;
+}
+
+static int
+do_detach( struct i2c_client *client )
+{
+	int err;
+
+	if( (err=i2c_detach_client(client)) )
+		printk(KERN_ERR "failed to detach thermostat client\n");
+	else {
+		if( x.running ) {
+			x.running = 0;
+			wait_for_completion( &x.completion );
+		}
+		if( client == x.thermostat )
+			x.thermostat = NULL;
+		else if( client == x.fan )
+			x.fan = NULL;
+		else {
+			printk(KERN_ERR "g4fan: bad client\n");
+		}
+		kfree( client );
+	}
+	return err;
+}
+
+static struct i2c_driver g4fan_driver = {  
+	.owner		= THIS_MODULE,
+	.name		= "therm_windtunnel",
+	.id		= I2C_DRIVERID_G4FAN,
+	.flags		= I2C_DF_NOTIFY,
+	.attach_adapter = do_attach,
+	.detach_client	= do_detach,
+};
+
+static int
+attach_fan( struct i2c_client *cl )
+{
+	if( x.fan )
+		goto out;
+
+	/* check that this is an ADM1030 */
+	if( read_reg(cl, 0x3d, 1) != 0x30 || read_reg(cl, 0x3e, 1) != 0x41 )
+		goto out;
+	printk("ADM1030 fan controller [@%02x]\n", cl->addr );
+
+	strlcpy( cl->name, "ADM1030 fan controller", sizeof(cl->name) );
+
+	if( !i2c_attach_client(cl) )
+		x.fan = cl;
+ out:
+	if( cl != x.fan )
+		kfree( cl );
+	return 0;
+}
+
+static int
+attach_thermostat( struct i2c_client *cl ) 
+{
+	int hyst_temp, os_temp, temp;
+
+	if( x.thermostat )
+		goto out;
+
+	if( (temp=read_reg(cl, 0, 2)) < 0 )
+		goto out;
+	
+	/* temperature sanity check */
+	if( temp < 0x1600 || temp > 0x3c00 )
+		goto out;
+	hyst_temp = read_reg(cl, 2, 2);
+	os_temp = read_reg(cl, 3, 2);
+	if( hyst_temp < 0 || os_temp < 0 )
+		goto out;
+
+	printk("DS1775 digital thermometer [@%02x]\n", cl->addr );
+	print_temp("Temp: ", temp );
+	print_temp("  Hyst: ", hyst_temp );
+	print_temp("  OS: ", os_temp );
+	printk("\n");
+
+	x.temp = temp;
+	x.overheat_temp = os_temp;
+	x.overheat_hyst = hyst_temp;
+	
+	strlcpy( cl->name, "DS1775 thermostat", sizeof(cl->name) );
+
+	if( !i2c_attach_client(cl) )
+		x.thermostat = cl;
+out:
+	if( cl != x.thermostat )
+		kfree( cl );
+	return 0;
+}
+
+static int
+do_probe( struct i2c_adapter *adapter, int addr, int kind )
+{
+	struct i2c_client *cl;
+
+	if( !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA
+				     | I2C_FUNC_SMBUS_WRITE_BYTE) )
+		return 0;
+
+	if( !(cl=kmalloc(sizeof(*cl), GFP_KERNEL)) )
+		return -ENOMEM;
+	memset( cl, 0, sizeof(struct i2c_client) );
+
+	cl->addr = addr;
+	cl->adapter = adapter;
+	cl->driver = &g4fan_driver;
+	cl->flags = 0;
+
+	if( addr < 0x48 )
+		return attach_fan( cl );
+	return attach_thermostat( cl );
+}
+
+
+/************************************************************************/
+/*	initialization / cleanup					*/
+/************************************************************************/
+
+static int
+therm_of_probe( struct of_device *dev, const struct of_match *match )
+{
+	return i2c_add_driver( &g4fan_driver );
+}
+
+static int
+therm_of_remove( struct of_device *dev )
+{
+	return i2c_del_driver( &g4fan_driver );
+}
+
+static struct of_match therm_of_match[] = {{
+	.name		= "fan",
+	.type		= OF_ANY_MATCH,
+	.compatible	= "adm1030"
+    }, {}
+};
+
+static struct of_platform_driver therm_of_driver = {
+	.name		= "temperature",
+	.match_table	= therm_of_match,
+	.probe		= therm_of_probe,
+	.remove		= therm_of_remove,
+};
+
+struct apple_thermal_info {
+	u8		id;			/* implementation ID */
+	u8		fan_count;		/* number of fans */
+	u8		thermostat_count;	/* number of thermostats */
+	u8		unused;
+};
+
+static int __init
+g4fan_init( void )
+{
+	struct apple_thermal_info *info;
+	struct device_node *np;
+
+	init_MUTEX( &x.lock );
+
+	if( !(np=of_find_node_by_name(NULL, "power-mgt")) )
+		return -ENODEV;
+	info = (struct apple_thermal_info*)get_property(np, "thermal-info", NULL);
+	of_node_put(np);
+
+	if( !info || !machine_is_compatible("PowerMac3,6") )
+		return -ENODEV;
+
+	if( info->id != 3 ) {
+		printk(KERN_ERR "therm_windtunnel: unsupported thermal design %d\n", info->id );
+		return -ENODEV;
+	}
+	if( !(np=of_find_node_by_name(NULL, "fan")) )
+		return -ENODEV;
+	x.of_dev = of_platform_device_create( np, "temperature" );
+	of_node_put( np );
+
+	if( !x.of_dev ) {
+		printk(KERN_ERR "Can't register fan controller!\n");
+		return -ENODEV;
+	}
+
+	of_register_driver( &therm_of_driver );
+	return 0;
+}
+
+static void __exit
+g4fan_exit( void )
+{
+	of_unregister_driver( &therm_of_driver );
+
+	if( x.of_dev )
+		of_device_unregister( x.of_dev );
+}
+
+module_init(g4fan_init);
+module_exit(g4fan_exit);
+
+MODULE_AUTHOR("Samuel Rydh <samuel@ibrium.se>");
+MODULE_DESCRIPTION("Apple G4 (windtunnel) fan controller");
+MODULE_LICENSE("GPL");