ppc32: Add thermal management drivers

Adds thermal management drivers for desktop G5, Windtunnel G4s, and
recent laptops (iBook G4, aluminium 15" and 17" powerbooks)

drivers/macintosh/Kconfig

@@ -127,6 +127,28 @@ config MAC_EMUMOUSEBTN
 
 	  If you have an Apple machine with a 1-button mouse, say Y here.
 
+config THERM_WINDTUNNEL
+	tristate "Support for thermal management on Windtunnel G4s"
+	depends on I2C && I2C_KEYWEST && !POWER4
+	help
+	  This driver provides some thermostat and fan control for the desktop
+	  G4 "Windtunnel"
+
+config THERM_ADT7467
+	tristate "Support for thermal mgmnt on laptops with ADT 7467 chipset"
+	depends on I2C && I2C_KEYWEST && !POWER4
+	help
+	  This driver provides some thermostat and fan control for the
+          iBook G4, and the ATI based aluminium PowerBooks, allowing slighlty
+	  better fan behaviour by default, and some manual control.
+
+config THERM_PM72
+	tristate "Support for thermal management on PowerMac G5"
+	depends on I2C && I2C_KEYWEST && POWER4
+	help
+	  This driver provides thermostat and fan control for the desktop
+	  G5 machines. 
+
 config ANSLCD
 	bool "Support for ANS LCD display"
 	depends on ADB_CUDA

drivers/macintosh/Makefile

@@ -22,3 +22,7 @@ obj-$(CONFIG_ADB_MACIISI)	+= via-maciisi.o
 obj-$(CONFIG_ADB_IOP)		+= adb-iop.o
 obj-$(CONFIG_ADB_PMU68K)	+= via-pmu68k.o
 obj-$(CONFIG_ADB_MACIO)		+= macio-adb.o
+
+obj-$(CONFIG_THERM_PM72)	+= therm_pm72.o
+obj-$(CONFIG_THERM_WINDTUNNEL)	+= therm_windtunnel.o
+obj-$(CONFIG_THERM_ADT7467)	+= therm_adt7467.o

drivers/macintosh/therm_adt7467.c

+/*
+ * Device driver for the i2c thermostat found on the iBook G4, Albook G4
+ *
+ * Copyright (C) 2003, 2004 Colin Leroy, Rasmus Rohde, Benjamin Herrenschmidt
+ *
+ * Documentation from
+ * http://www.analog.com/UploadedFiles/Data_Sheets/115254175ADT7467_pra.pdf
+ * http://www.analog.com/UploadedFiles/Data_Sheets/3686221171167ADT7460_b.pdf
+ *
+ */
+
+#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 <linux/spinlock.h>
+#include <linux/smp_lock.h>
+#include <linux/wait.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>
+
+#undef DEBUG
+
+#define CONFIG_REG   0x40
+#define MANUAL_MASK  0xe0
+#define AUTO_MASK    0x20
+
+static u8 TEMP_REG[3]    = {0x26, 0x25, 0x27}; /* local, cpu, gpu */
+static u8 LIMIT_REG[3]   = {0x6b, 0x6a, 0x6c}; /* local, cpu, gpu */
+static u8 MANUAL_MODE[2] = {0x5c, 0x5d};       
+static u8 REM_CONTROL[2] = {0x00, 0x40};
+static u8 FAN_SPEED[2]   = {0x28, 0x2a};
+static u8 FAN_SPD_SET[2] = {0x30, 0x31};
+
+static u8 default_limits_local[3] = {70, 50, 70};    /* local, cpu, gpu */
+static u8 default_limits_chip[3] = {80, 65, 80};    /* local, cpu, gpu */
+
+static int limit_adjust = 0;
+static int fan_speed = -1;
+
+MODULE_AUTHOR("Colin Leroy <colin@colino.net>");
+MODULE_DESCRIPTION("Driver for ADT7467 thermostat in iBook G4");
+MODULE_LICENSE("GPL");
+
+MODULE_PARM(limit_adjust,"i");
+MODULE_PARM_DESC(limit_adjust,"Adjust maximum temperatures (50°C cpu, 70°C gpu) by N °C.");
+MODULE_PARM(fan_speed,"i");
+MODULE_PARM_DESC(fan_speed,"Specify fan speed (0-255) when lim < temp < lim+8 (default 128)");
+
+struct thermostat {
+	struct i2c_client	clt;
+	u8			cached_temp[3];
+	u8			initial_limits[3];
+	u8			limits[3];
+	int			last_speed[2];
+	int			overriding[2];
+};
+
+static enum {ADT7460, ADT7467} therm_type;
+static int therm_bus, therm_address;
+static struct of_device * of_dev;
+static struct thermostat* thermostat;
+static pid_t monitor_thread_id;
+static int monitor_running;
+static struct completion monitor_task_compl;
+
+static int attach_one_thermostat(struct i2c_adapter *adapter, int addr, int busno);
+static void write_both_fan_speed(struct thermostat *th, int speed);
+static void write_fan_speed(struct thermostat *th, int speed, int fan);
+
+static int
+write_reg(struct thermostat* th, int reg, u8 data)
+{
+	u8 tmp[2];
+	int rc;
+	
+	tmp[0] = reg;
+	tmp[1] = data;
+	rc = i2c_master_send(&th->clt, (const char *)tmp, 2);
+	if (rc < 0)
+		return rc;
+	if (rc != 2)
+		return -ENODEV;
+	return 0;
+}
+
+static int
+read_reg(struct thermostat* th, int reg)
+{
+	u8 reg_addr, data;
+	int rc;
+
+	reg_addr = (u8)reg;
+	rc = i2c_master_send(&th->clt, &reg_addr, 1);
+	if (rc < 0)
+		return rc;
+	if (rc != 1)
+		return -ENODEV;
+	rc = i2c_master_recv(&th->clt, (char *)&data, 1);
+	if (rc < 0)
+		return rc;
+	return data;
+}
+
+static int
+attach_thermostat(struct i2c_adapter *adapter)
+{
+	unsigned long bus_no;
+
+	if (strncmp(adapter->name, "uni-n", 5))
+		return -ENODEV;
+	bus_no = simple_strtoul(adapter->name + 6, NULL, 10);
+	if (bus_no != therm_bus)
+		return -ENODEV;
+	return attach_one_thermostat(adapter, therm_address, bus_no);
+}
+
+static int
+detach_thermostat(struct i2c_adapter *adapter)
+{
+	struct thermostat* th;
+	int i;
+	
+	if (thermostat == NULL)
+		return 0;
+
+	th = thermostat;
+
+	if (monitor_running) {
+		monitor_running = 0;
+		wait_for_completion(&monitor_task_compl);
+	}
+		
+	printk(KERN_INFO "adt746x: Putting max temperatures back from %d, %d, %d,"
+		" to %d, %d, %d, (°C)\n", 
+		th->limits[0], th->limits[1], th->limits[2],
+		th->initial_limits[0], th->initial_limits[1], th->initial_limits[2]);
+	
+	for (i = 0; i < 3; i++)
+		write_reg(th, LIMIT_REG[i], th->initial_limits[i]);
+
+	write_both_fan_speed(th, -1);
+
+	i2c_detach_client(&th->clt);
+
+	thermostat = NULL;
+
+	kfree(th);
+
+	return 0;
+}
+
+static struct i2c_driver thermostat_driver = {  
+	.name		="Apple Thermostat ADT7467",
+	.id		=0xDEAD7467,
+	.flags		=I2C_DF_NOTIFY,
+	.attach_adapter	=&attach_thermostat,
+	.detach_adapter	=&detach_thermostat,
+};
+
+static int read_fan_speed(struct thermostat *th, u8 addr)
+{
+	u8 tmp[2];
+	u16 res;
+	
+	/* should start with low byte */
+	tmp[1] = read_reg(th, addr);
+	tmp[0] = read_reg(th, addr + 1);
+	
+	res = tmp[1] + (tmp[0] << 8);
+	return (90000*60)/res;
+}
+
+static void write_both_fan_speed(struct thermostat *th, int speed)
+{
+	write_fan_speed(th, speed, 0);
+	if (therm_type == ADT7460)
+		write_fan_speed(th, speed, 1);
+}
+
+static void write_fan_speed(struct thermostat *th, int speed, int fan)
+{
+	u8 manual;
+	
+	if (speed > 0xff) 
+		speed = 0xff;
+	else if (speed < -1) 
+		speed = 0;
+	
+	if (therm_type == ADT7467 && fan == 1)
+		return;
+	
+	if (th->last_speed[fan] != speed) {
+		if (speed == -1)
+			printk(KERN_INFO "adt746x: Setting speed to: automatic for %s fan.\n",
+				fan?"GPU":"CPU");
+		else
+			printk(KERN_INFO "adt746x: Setting speed to: %d for %s fan.\n",
+				speed, fan?"GPU":"CPU");
+	} else
+		return;
+	
+	if (speed >= 0) {
+		manual = read_reg(th, MANUAL_MODE[fan]);
+		write_reg(th, MANUAL_MODE[fan], manual|MANUAL_MASK);
+		write_reg(th, FAN_SPD_SET[fan], speed);
+	} else {
+		/* back to automatic */
+		if(therm_type == ADT7460) {
+			manual = read_reg(th, MANUAL_MODE[fan]) & (~MANUAL_MASK);
+			write_reg(th, MANUAL_MODE[fan], manual|REM_CONTROL[fan]);
+		} else {
+			manual = read_reg(th, MANUAL_MODE[fan]);
+			write_reg(th, MANUAL_MODE[fan], manual&(~AUTO_MASK));
+		}
+	}
+	
+	th->last_speed[fan] = speed;			
+}
+
+static int monitor_task(void *arg)
+{
+	struct thermostat* th = arg;
+	u8 temps[3];
+	u8 lims[3];
+	int i;
+#ifdef DEBUG
+	int mfan_speed;
+#endif
+	
+	lock_kernel();
+	daemonize("kfand");
+	unlock_kernel();
+	strcpy(current->comm, "thermostat");
+	monitor_running = 1;
+
+	while(monitor_running)
+	{
+		set_task_state(current, TASK_UNINTERRUPTIBLE);
+		schedule_timeout(2*HZ);
+
+		/* Check status */
+		/* local   : chip */
+		/* remote 1: CPU ?*/
+		/* remote 2: GPU ?*/
+#ifndef DEBUG
+		if (fan_speed != -1) {
+#endif
+			for (i = 0; i < 3; i++) {
+				temps[i]  = read_reg(th, TEMP_REG[i]);
+				lims[i]   = th->limits[i];
+			}
+#ifndef DEBUG
+		}
+#endif		
+		if (fan_speed != -1) {
+			int lastvar = 0;		/* for iBook */
+			for (i = 1; i < 3; i++) {	/* we don't care about local sensor */
+				int started = 0;
+				int fan_number = (therm_type == ADT7460 && i == 2);
+				int var = temps[i] - lims[i];
+				if (var > 8) {
+					if (th->overriding[fan_number] == 0)
+						printk(KERN_INFO "adt746x: Limit exceeded by %d°C, overriding specified fan speed for %s.\n",
+							var, fan_number?"GPU":"CPU");
+					th->overriding[fan_number] = 1;
+					write_fan_speed(th, 255, fan_number);
+					started = 1;
+				} else if ((!th->overriding[fan_number] || var < 6) && var > 0) {
+					if (th->overriding[fan_number] == 1)
+						printk(KERN_INFO "adt746x: Limit exceeded by %d°C, setting speed to specified for %s.\n",
+							var, fan_number?"GPU":"CPU");					
+					th->overriding[fan_number] = 0;
+					write_fan_speed(th, fan_speed, fan_number);
+					started = 1;
+				} else if (var < -1) {
+					/* don't stop iBook fan if GPU is cold and CPU is not
+					 * so cold (lastvar >= -1) */
+					if (therm_type == ADT7460 || lastvar < -1 || i == 1) {
+						if (th->last_speed[fan_number] != 0)
+							printk(KERN_INFO "adt746x: Stopping %s fan.\n",
+								fan_number?"GPU":"CPU");
+						write_fan_speed(th, 0, fan_number);
+					}
+				}
+				
+				lastvar = var;
+				
+				if (started && therm_type == ADT7467)
+					break; /* we don't want to re-stop the fan
+						* if CPU is heating and GPU is not */
+			}
+		}
+#ifdef DEBUG
+		mfan_speed = read_fan_speed(th, FAN_SPEED[0]);
+		/* only one fan in the iBook G4 */
+				
+		if (temps[0] != th->cached_temp[0]
+		||  temps[1] != th->cached_temp[1]
+		||  temps[2] != th->cached_temp[2]) {
+			printk(KERN_INFO "adt746x: Temperature infos:"
+					 " thermostats: %d,%d,%d °C;"
+					 " limits: %d,%d,%d °C;"
+					 " fan speed: %d RPM\n",
+				temps[0], temps[1], temps[2],
+				lims[0],  lims[1],  lims[2],
+				mfan_speed);
+		}
+		th->cached_temp[0] = temps[0];
+		th->cached_temp[1] = temps[1];
+		th->cached_temp[2] = temps[2];
+#endif		
+	}
+
+	complete_and_exit(&monitor_task_compl, 0);
+	return 0;
+}
+
+static void
+set_limit(struct thermostat *th, int i)
+{
+		/* Set CPU limit higher to avoid powerdowns */ 
+		th->limits[i] = default_limits_chip[i] + limit_adjust;
+		write_reg(th, LIMIT_REG[i], th->limits[i]);
+		
+		/* set our limits to normal */
+		th->limits[i] = default_limits_local[i] + limit_adjust;
+}
+	
+static int
+attach_one_thermostat(struct i2c_adapter *adapter, int addr, int busno)
+{
+	struct thermostat* th;
+	int rc;
+	int i;
+
+	if (thermostat)
+		return 0;
+	th = (struct thermostat *)kmalloc(sizeof(struct thermostat), GFP_KERNEL);
+	if (!th)
+		return -ENOMEM;
+	memset(th, 0, sizeof(*th));
+	th->clt.addr = addr;
+	th->clt.adapter = adapter;
+	th->clt.driver = &thermostat_driver;
+	th->clt.id = 0xDEAD7467;
+	strcpy(th->clt.name, "thermostat");
+
+	rc = read_reg(th, 0);
+	if (rc < 0) {
+		printk(KERN_ERR "adt746x: Thermostat failed to read config from bus %d !\n",
+			busno);
+		kfree(th);
+		return -ENODEV;
+	}
+	/* force manual control to start the fan quieter */
+	
+	if (fan_speed == -1)
+		fan_speed=128;
+	
+	if(therm_type == ADT7460) {
+		printk(KERN_INFO "adt746x: ADT7460 initializing\n");
+		/* The 7460 needs to be started explicitly */
+		write_reg(th, CONFIG_REG, 1);
+	} else
+		printk(KERN_INFO "adt746x: ADT7467 initializing\n");
+
+	for (i = 0; i < 3; i++) {
+		th->initial_limits[i] = read_reg(th, LIMIT_REG[i]);
+		set_limit(th, i);
+	}
+	
+	printk(KERN_INFO "adt746x: Lowering max temperatures from %d, %d, %d"
+		" to %d, %d, %d (°C)\n", 
+		th->initial_limits[0], th->initial_limits[1], th->initial_limits[2], 
+		th->limits[0], th->limits[1], th->limits[2]);
+
+	thermostat = th;
+
+	if (i2c_attach_client(&th->clt)) {
+		printk("adt746x: Thermostat failed to attach client !\n");
+		thermostat = NULL;
+		kfree(th);
+		return -ENODEV;
+	}
+
+	/* be sure to really write fan speed the first time */
+	th->last_speed[0] = -2;
+	th->last_speed[1] = -2;
+	
+	if (fan_speed != -1) {
+		write_both_fan_speed(th, 0);
+	} else {
+		write_both_fan_speed(th, -1);
+	}
+	
+	init_completion(&monitor_task_compl);
+	
+	monitor_thread_id = kernel_thread(monitor_task, th,
+		SIGCHLD | CLONE_KERNEL);
+
+	return 0;
+}
+
+/* 
+ * Now, unfortunately, sysfs doesn't give us a nice void * we could
+ * pass around to the attribute functions, so we don't really have
+ * choice but implement a bunch of them...
+ *
+ */
+#define BUILD_SHOW_FUNC_DEG(name, data)				\
+static ssize_t show_##name(struct device *dev, char *buf)	\
+{								\
+	return sprintf(buf, "%d°C\n", data);			\
+}
+#define BUILD_SHOW_FUNC_INT(name, data)				\
+static ssize_t show_##name(struct device *dev, char *buf)	\
+{								\
+	return sprintf(buf, "%d\n", data);			\
+}
+
+#define BUILD_STORE_FUNC_DEG(name, data)			\
+static ssize_t store_##name(struct device *dev, const char *buf, size_t n) \
+{								\
+	int val;						\
+	int i;							\
+	val = simple_strtol(buf, NULL, 10);			\
+	printk(KERN_INFO "Adjusting limits by %d°C\n", val);	\
+	limit_adjust = val;					\
+	for (i=0; i < 3; i++)					\
+		set_limit(thermostat, i);			\
+	return n;						\
+}
+
+#define BUILD_STORE_FUNC_INT(name, data)			\
+static ssize_t store_##name(struct device *dev, const char *buf, size_t n) \
+{								\
+	u32 val;						\
+	val = simple_strtoul(buf, NULL, 10);			\
+	if (val < 0 || val > 255)				\
+		return -EINVAL;					\
+	printk(KERN_INFO "Setting fan speed to %d\n", val);	\
+	data = val;						\
+	return n;						\
+}
+
+BUILD_SHOW_FUNC_DEG(cpu_temperature,	 (read_reg(thermostat, TEMP_REG[1])))
+BUILD_SHOW_FUNC_DEG(gpu_temperature,	 (read_reg(thermostat, TEMP_REG[2])))
+BUILD_SHOW_FUNC_DEG(cpu_limit,		 thermostat->limits[1])
+BUILD_SHOW_FUNC_DEG(gpu_limit,		 thermostat->limits[2])
+
+BUILD_SHOW_FUNC_INT(specified_fan_speed, fan_speed)
+BUILD_SHOW_FUNC_INT(cpu_fan_speed,	 (read_fan_speed(thermostat, FAN_SPEED[0])))
+BUILD_SHOW_FUNC_INT(gpu_fan_speed,	 (read_fan_speed(thermostat, FAN_SPEED[1])))
+
+BUILD_STORE_FUNC_INT(specified_fan_speed,fan_speed)
+BUILD_SHOW_FUNC_INT(limit_adjust,	 limit_adjust)
+BUILD_STORE_FUNC_DEG(limit_adjust,	 thermostat)
+		
+static DEVICE_ATTR(cpu_temperature,	S_IRUGO,
+		   show_cpu_temperature,NULL);
+static DEVICE_ATTR(gpu_temperature,	S_IRUGO,
+		   show_gpu_temperature,NULL);
+static DEVICE_ATTR(cpu_limit,		S_IRUGO,
+		   show_cpu_limit,	NULL);
+static DEVICE_ATTR(gpu_limit,		S_IRUGO,
+		   show_gpu_limit,	NULL);
+
+static DEVICE_ATTR(specified_fan_speed,	S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH,
+		   show_specified_fan_speed,store_specified_fan_speed);
+
+static DEVICE_ATTR(cpu_fan_speed,	S_IRUGO,
+		   show_cpu_fan_speed,	NULL);
+static DEVICE_ATTR(gpu_fan_speed,	S_IRUGO,
+		   show_gpu_fan_speed,	NULL);
+
+static DEVICE_ATTR(limit_adjust,	S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH,
+		   show_limit_adjust,	store_limit_adjust);
+
+
+static int __init
+thermostat_init(void)
+{
+	struct device_node* np;
+	u32 *prop;
+	
+	/* Currently, we only deal with the iBook G4, we will support
+	 * all "2003" powerbooks later on
+	 */
+	np = of_find_node_by_name(NULL, "fan");
+	if (!np)
+		return -ENODEV;
+	if (device_is_compatible(np, "adt7460"))
+		therm_type = ADT7460;
+	else if (device_is_compatible(np, "adt7467"))
+		therm_type = ADT7467;
+	else
+		return -ENODEV;
+
+	prop = (u32 *)get_property(np, "reg", NULL);
+	if (!prop)
+		return -ENODEV;
+	therm_bus = ((*prop) >> 8) & 0x0f;
+	therm_address = ((*prop) & 0xff) >> 1;
+
+	printk(KERN_INFO "adt746x: Thermostat bus: %d, address: 0x%02x, limit_adjust: %d, fan_speed: %d\n",
+		therm_bus, therm_address, limit_adjust, fan_speed);
+
+	of_dev = of_platform_device_create(np, "temperatures");
+	
+	if (of_dev == NULL) {
+		printk(KERN_ERR "Can't register temperatures device !\n");
+		return -ENODEV;
+	}
+	
+	device_create_file(&of_dev->dev, &dev_attr_cpu_temperature);
+	device_create_file(&of_dev->dev, &dev_attr_gpu_temperature);
+	device_create_file(&of_dev->dev, &dev_attr_cpu_limit);
+	device_create_file(&of_dev->dev, &dev_attr_gpu_limit);
+	device_create_file(&of_dev->dev, &dev_attr_limit_adjust);
+	device_create_file(&of_dev->dev, &dev_attr_specified_fan_speed);
+	device_create_file(&of_dev->dev, &dev_attr_cpu_fan_speed);
+	if(therm_type == ADT7460)
+		device_create_file(&of_dev->dev, &dev_attr_gpu_fan_speed);
+
+#ifndef CONFIG_I2C_KEYWEST
+	request_module("i2c-keywest");
+#endif
+
+	return i2c_add_driver(&thermostat_driver);
+}
+
+static void __exit
+thermostat_exit(void)
+{
+	if (of_dev) {
+		device_remove_file(&of_dev->dev, &dev_attr_cpu_temperature);
+		device_remove_file(&of_dev->dev, &dev_attr_gpu_temperature);
+		device_remove_file(&of_dev->dev, &dev_attr_cpu_limit);
+		device_remove_file(&of_dev->dev, &dev_attr_gpu_limit);
+		device_remove_file(&of_dev->dev, &dev_attr_limit_adjust);
+		device_remove_file(&of_dev->dev, &dev_attr_specified_fan_speed);
+		device_remove_file(&of_dev->dev, &dev_attr_cpu_fan_speed);
+		if(therm_type == ADT7460)
+			device_remove_file(&of_dev->dev, &dev_attr_gpu_fan_speed);
+		of_device_unregister(of_dev);
+	}
+	i2c_del_driver(&thermostat_driver);
+}
+
+module_init(thermostat_init);
+module_exit(thermostat_exit);

drivers/macintosh/therm_pm72.c

+/*
+ * Device driver for the thermostats & fan controller of  the
+ * Apple G5 "PowerMac7,2" desktop machines.
+ *
+ * (c) Copyright IBM Corp. 2003
+ *
+ * Maintained by: Benjamin Herrenschmidt
+ *                <benh@kernel.crashing.org>
+ * 
+ *
+ * The algorithm used is the PID control algorithm, used the same
+ * way the published Darwin code does, using the same values that
+ * are present in the Darwin 7.0 snapshot property lists.
+ *
+ * As far as the CPUs control loops are concerned, I use the
+ * calibration & PID constants provided by the EEPROM,
+ * I do _not_ embed any value from the property lists, as the ones
+ * provided by Darwin 7.0 seem to always have an older version that
+ * what I've seen on the actual computers.
+ * It would be interesting to verify that though. Darwin has a
+ * version code of 1.0.0d11 for all control loops it seems, while
+ * so far, the machines EEPROMs contain a dataset versioned 1.0.0f
+ *
+ * Darwin doesn't provide source to all parts, some missing
+ * bits like the AppleFCU driver or the actual scale of some
+ * of the values returned by sensors had to be "guessed" some
+ * way... or based on what Open Firmware does.
+ *
+ * I didn't yet figure out how to get the slots power consumption
+ * out of the FCU, so that part has not been implemented yet and
+ * the slots fan is set to a fixed 50% PWM, hoping this value is
+ * safe enough ...
+ *
+ * Note: I have observed strange oscillations of the CPU control
+ * loop on a dual G5 here. When idle, the CPU exhaust fan tend to
+ * oscillates slowly (over several minutes) between the minimum
+ * of 300RPMs and approx. 1000 RPMs. I don't know what is causing
+ * this, it could be some incorrect constant or an error in the
+ * way I ported the algorithm, or it could be just normal. I
+ * don't have full understanding on the way Apple tweaked the PID
+ * algorithm for the CPU control, it is definitely not a standard
+ * implementation...
+ *
+ * TODO:  - Check MPU structure version/signature
+ *        - Add things like /sbin/overtemp for non-critical
+ *          overtemp conditions so userland can take some policy
+ *          decisions, like slewing down CPUs
+ *	  - Deal with fan failures
+ *
+ * History:
+ *
+ *  Nov. 13, 2003 : 0.5
+ *	- First release
+ *
+ *  Nov. 14, 2003 : 0.6
+ *	- Read fan speed from FCU, low level fan routines now deal
+ *	  with errors & check fan status, though higher level don't
+ *	  do much.
+ *	- Move a bunch of definitions to .h file
+ *
+ *  Nov. 18, 2003 : 0.7
+ *	- Fix build on ppc64 kernel
+ *	- Move back statics definitions to .c file
+ *	- Avoid calling schedule_timeout with a negative number
+ *
+ *  Dev. 18, 2003 : 0.8
+ *	- Fix typo when reading back fan speed on 2 CPU machines
+ *
+ */
+
+#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 <linux/spinlock.h>
+#include <linux/smp_lock.h>
+#include <linux/wait.h>
+#include <linux/reboot.h>
+#include <linux/kmod.h>
+#include <linux/i2c.h>
+#include <linux/i2c-dev.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>
+
+#include "therm_pm72.h"
+
+#define VERSION "0.8"
+
+#undef DEBUG
+
+#ifdef DEBUG
+#define DBG(args...)	printk(args)
+#else
+#define DBG(args...)
+#endif
+
+
+/*
+ * Driver statics
+ */
+
+static struct of_device *		of_dev;
+static struct i2c_adapter *		u3_0;
+static struct i2c_adapter *		u3_1;
+static struct i2c_client *		fcu;
+static struct cpu_pid_state		cpu_state[2];
+static struct backside_pid_state	backside_state;
+static struct drives_pid_state		drives_state;
+static int				state;
+static int				cpu_count;
+static pid_t				ctrl_task;
+static struct completion		ctrl_complete;
+static int				critical_state;
+static DECLARE_MUTEX(driver_lock);
+
+/*
+ * i2c_driver structure to attach to the host i2c controller
+ */
+
+static int therm_pm72_attach(struct i2c_adapter *adapter);
+static int therm_pm72_detach(struct i2c_adapter *adapter);
+
+static struct i2c_driver therm_pm72_driver =
+{
+	.name		= "therm_pm72",
+	.id		= 0xDEADBEEF,
+	.flags		= I2C_DF_NOTIFY,
+	.attach_adapter	= therm_pm72_attach,
+	.detach_adapter	= therm_pm72_detach,
+};
+
+
+static inline void wait_ms(unsigned int ms)
+{
+	set_current_state(TASK_UNINTERRUPTIBLE);
+	schedule_timeout(1 + (ms * HZ + 999) / 1000);
+}
+
+/*
+ * Utility function to create an i2c_client structure and
+ * attach it to one of u3 adapters
+ */
+static struct i2c_client *attach_i2c_chip(int id, const char *name)
+{
+	struct i2c_client *clt;
+	struct i2c_adapter *adap;
+
+	if (id & 0x100)
+		adap = u3_1;
+	else
+		adap = u3_0;
+	if (adap == NULL)
+		return NULL;
+
+	clt = kmalloc(sizeof(struct i2c_client), GFP_KERNEL);
+	if (clt == NULL)
+		return NULL;
+	memset(clt, 0, sizeof(struct i2c_client));
+
+	clt->addr = (id >> 1) & 0x7f;
+	clt->adapter = adap;
+	clt->driver = &therm_pm72_driver;
+	clt->id = 0xDEADBEEF;
+	strncpy(clt->name, name, I2C_NAME_SIZE-1);
+
+	if (i2c_attach_client(clt)) {
+		printk(KERN_ERR "therm_pm72: Failed to attach to i2c ID 0x%x\n", id);
+		kfree(clt);
+		return NULL;
+	}
+	return clt;
+}
+
+/*
+ * Utility function to get rid of the i2c_client structure
+ * (will also detach from the adapter hopepfully)
+ */
+static void detach_i2c_chip(struct i2c_client *clt)
+{
+	i2c_detach_client(clt);
+	kfree(clt);
+}
+
+/*
+ * Here are the i2c chip access wrappers
+ */
+static int read_smon_adc(struct i2c_client *chip, int chan)
+{
+	int ctrl;
+
+	ctrl = i2c_smbus_read_byte_data(chip, 1);
+	i2c_smbus_write_byte_data(chip, 1, (ctrl & 0x1f) | (chan << 5));
+	wait_ms(1);
+	return le16_to_cpu(i2c_smbus_read_word_data(chip, 4)) >> 6;
+}
+
+static int fan_read_reg(int reg, unsigned char *buf, int nb)
+{
+	int tries, nr, nw;
+
+	buf[0] = reg;
+	tries = 0;
+	for (;;) {
+		nw = i2c_master_send(fcu, buf, 1);
+		if (nw > 0 || (nw < 0 && nw != -EIO) || tries >= 100)
+			break;
+		wait_ms(10);
+		++tries;
+	}
+	if (nw <= 0) {
+		printk(KERN_ERR "Failure writing address to FCU: %d", nw);
+		return -EIO;
+	}
+	tries = 0;
+	for (;;) {
+		nr = i2c_master_recv(fcu, buf, nb);
+		if (nr > 0 || (nr < 0 && nr != ENODEV) || tries >= 100)
+			break;
+		wait_ms(10);
+		++tries;
+	}
+	if (nr <= 0)
+		printk(KERN_ERR "Failure reading data from FCU: %d", nw);
+	return nr;
+}
+
+static int fan_write_reg(int reg, const unsigned char *ptr, int nb)
+{
+	int tries, nw;
+	unsigned char buf[16];
+
+	buf[0] = reg;
+	memcpy(buf+1, ptr, nb);
+	++nb;
+	tries = 0;
+	for (;;) {
+		nw = i2c_master_send(fcu, buf, nb);
+		if (nw > 0 || (nw < 0 && nw != EIO) || tries >= 100)
+			break;
+		wait_ms(10);
+		++tries;
+	}
+	if (nw < 0)
+		printk(KERN_ERR "Failure writing to FCU: %d", nw);
+	return nw;
+}
+
+static int set_rpm_fan(int fan, int rpm)
+{
+	unsigned char buf[2];
+	int rc;
+
+	if (rpm < 300)
+		rpm = 300;
+	else if (rpm > 8191)
+		rpm = 8191;
+	buf[0] = rpm >> 5;
+	buf[1] = rpm << 3;
+	rc = fan_write_reg(0x10 + (fan * 2), buf, 2);
+	if (rc < 0)
+		return -EIO;
+	return 0;
+}
+
+static int get_rpm_fan(int fan, int programmed)
+{
+	unsigned char failure;
+	unsigned char active;
+	unsigned char buf[2];
+	int rc, reg_base;
+
+	rc = fan_read_reg(0xb, &failure, 1);
+	if (rc != 1)
+		return -EIO;
+	if ((failure & (1 << fan)) != 0)
+		return -EFAULT;
+	rc = fan_read_reg(0xd, &active, 1);
+	if (rc != 1)
+		return -EIO;
+	if ((active & (1 << fan)) == 0)
+		return -ENXIO;
+
+	/* Programmed value or real current speed */
+	reg_base = programmed ? 0x10 : 0x11;
+	rc = fan_read_reg(reg_base + (fan * 2), buf, 2);
+	if (rc != 2)
+		return -EIO;
+
+	return (buf[0] << 5) | buf[1] >> 3;
+}
+
+static int set_pwm_fan(int fan, int pwm)
+{
+	unsigned char buf[2];
+	int rc;
+
+	if (pwm < 10)
+		pwm = 10;
+	else if (pwm > 100)
+		pwm = 100;
+	pwm = (pwm * 2559) / 1000;
+	buf[0] = pwm;
+	rc = fan_write_reg(0x30 + (fan * 2), buf, 1);
+	if (rc < 0)
+		return rc;
+	return 0;
+}
+
+static int get_pwm_fan(int fan)
+{
+	unsigned char failure;
+	unsigned char active;
+	unsigned char buf[2];
+	int rc;
+
+	rc = fan_read_reg(0x2b, &failure, 1);
+	if (rc != 1)
+		return -EIO;
+	if ((failure & (1 << fan)) != 0)
+		return -EFAULT;
+	rc = fan_read_reg(0x2d, &active, 1);
+	if (rc != 1)
+		return -EIO;
+	if ((active & (1 << fan)) == 0)
+		return -ENXIO;
+
+	/* Programmed value or real current speed */
+	rc = fan_read_reg(0x30 + (fan * 2), buf, 1);
+	if (rc != 1)
+		return -EIO;
+
+	return (buf[0] * 1000) / 2559;
+}
+
+/*
+ * Utility routine to read the CPU calibration EEPROM data
+ * from the device-tree
+ */
+static int read_eeprom(int cpu, struct mpu_data *out)
+{
+	struct device_node *np;
+	char nodename[64];
+	u8 *data;
+	int len;
+
+	/* prom.c routine for finding a node by path is a bit brain dead
+	 * and requires exact @xxx unit numbers. This is a bit ugly but
+	 * will work for these machines
+	 */
+	sprintf(nodename, "/u3@0,f8000000/i2c@f8001000/cpuid@a%d", cpu ? 2 : 0);
+	np = of_find_node_by_path(nodename);
+	if (np == NULL) {
+		printk(KERN_ERR "therm_pm72: Failed to retreive cpuid node from device-tree\n");
+		return -ENODEV;
+	}
+	data = (u8 *)get_property(np, "cpuid", &len);
+	if (data == NULL) {
+		printk(KERN_ERR "therm_pm72: Failed to retreive cpuid property from device-tree\n");
+		of_node_put(np);
+		return -ENODEV;
+	}
+	memcpy(out, data, sizeof(struct mpu_data));
+	of_node_put(np);
+	
+	return 0;
+}
+
+/* 
+ * Now, unfortunately, sysfs doesn't give us a nice void * we could
+ * pass around to the attribute functions, so we don't really have
+ * choice but implement a bunch of them...
+ *
+ * That sucks a bit, we take the lock because FIX32TOPRINT evaluates
+ * the input twice... I accept patches :)
+ */
+#define BUILD_SHOW_FUNC_FIX(name, data)				\
+static ssize_t show_##name(struct device *dev, char *buf)	\
+{								\
+	ssize_t r;						\
+	down(&driver_lock);					\
+	r = sprintf(buf, "%d.%03d", FIX32TOPRINT(data));	\
+	up(&driver_lock);					\
+	return r;						\
+}
+#define BUILD_SHOW_FUNC_INT(name, data)				\
+static ssize_t show_##name(struct device *dev, char *buf)	\
+{								\
+	return sprintf(buf, "%d", data);			\
+}
+
+BUILD_SHOW_FUNC_FIX(cpu0_temperature, cpu_state[0].last_temp)
+BUILD_SHOW_FUNC_FIX(cpu0_voltage, cpu_state[0].voltage)
+BUILD_SHOW_FUNC_FIX(cpu0_current, cpu_state[0].current_a)
+BUILD_SHOW_FUNC_INT(cpu0_exhaust_fan_rpm, cpu_state[0].rpm)
+BUILD_SHOW_FUNC_INT(cpu0_intake_fan_rpm, cpu_state[0].intake_rpm)
+
+BUILD_SHOW_FUNC_FIX(cpu1_temperature, cpu_state[1].last_temp)
+BUILD_SHOW_FUNC_FIX(cpu1_voltage, cpu_state[1].voltage)
+BUILD_SHOW_FUNC_FIX(cpu1_current, cpu_state[1].current_a)
+BUILD_SHOW_FUNC_INT(cpu1_exhaust_fan_rpm, cpu_state[1].rpm)
+BUILD_SHOW_FUNC_INT(cpu1_intake_fan_rpm, cpu_state[1].intake_rpm)
+
+BUILD_SHOW_FUNC_FIX(backside_temperature, backside_state.last_temp)
+BUILD_SHOW_FUNC_INT(backside_fan_pwm, backside_state.pwm)
+
+BUILD_SHOW_FUNC_FIX(drives_temperature, drives_state.last_temp)
+BUILD_SHOW_FUNC_INT(drives_fan_rpm, drives_state.rpm)
+
+static DEVICE_ATTR(cpu0_temperature,S_IRUGO,show_cpu0_temperature,NULL);
+static DEVICE_ATTR(cpu0_voltage,S_IRUGO,show_cpu0_voltage,NULL);
+static DEVICE_ATTR(cpu0_current,S_IRUGO,show_cpu0_current,NULL);
+static DEVICE_ATTR(cpu0_exhaust_fan_rpm,S_IRUGO,show_cpu0_exhaust_fan_rpm,NULL);
+static DEVICE_ATTR(cpu0_intake_fan_rpm,S_IRUGO,show_cpu0_intake_fan_rpm,NULL);
+
+static DEVICE_ATTR(cpu1_temperature,S_IRUGO,show_cpu1_temperature,NULL);
+static DEVICE_ATTR(cpu1_voltage,S_IRUGO,show_cpu1_voltage,NULL);
+static DEVICE_ATTR(cpu1_current,S_IRUGO,show_cpu1_current,NULL);
+static DEVICE_ATTR(cpu1_exhaust_fan_rpm,S_IRUGO,show_cpu1_exhaust_fan_rpm,NULL);
+static DEVICE_ATTR(cpu1_intake_fan_rpm,S_IRUGO,show_cpu1_intake_fan_rpm,NULL);
+
+static DEVICE_ATTR(backside_temperature,S_IRUGO,show_backside_temperature,NULL);
+static DEVICE_ATTR(backside_fan_pwm,S_IRUGO,show_backside_fan_pwm,NULL);
+
+static DEVICE_ATTR(drives_temperature,S_IRUGO,show_drives_temperature,NULL);
+static DEVICE_ATTR(drives_fan_rpm,S_IRUGO,show_drives_fan_rpm,NULL);
+
+/*
+ * CPUs fans control loop
+ */
+static void do_monitor_cpu(struct cpu_pid_state *state)
+{
+	s32 temp, voltage, current_a, power, power_target;
+	s32 integral, derivative, proportional, adj_in_target, sval;
+	s64 integ_p, deriv_p, prop_p, sum; 
+	int i, intake, rc;
+
+	DBG("cpu %d:\n", state->index);
+
+	/* Read current fan status */
+	if (state->index == 0)
+		rc = get_rpm_fan(CPUA_EXHAUST_FAN_RPM_ID, !RPM_PID_USE_ACTUAL_SPEED);
+	else
+		rc = get_rpm_fan(CPUB_EXHAUST_FAN_RPM_ID, !RPM_PID_USE_ACTUAL_SPEED);
+	if (rc < 0) {
+		printk(KERN_WARNING "Error %d reading CPU %d exhaust fan !\n",
+		       rc, state->index);
+		/* XXX What do we do now ? */
+	} else
+		state->rpm = rc;
+	DBG("  current rpm: %d\n", state->rpm);
+
+	/* Get some sensor readings and scale it */
+	temp = read_smon_adc(state->monitor, 1);
+	voltage = read_smon_adc(state->monitor, 3);
+	current_a = read_smon_adc(state->monitor, 4);
+
+	/* Fixup temperature according to diode calibration
+	 */
+	DBG("  temp raw: %04x, m_diode: %04x, b_diode: %04x\n",
+	    temp, state->mpu.mdiode, state->mpu.bdiode);
+	temp = ((s32)temp * (s32)state->mpu.mdiode + ((s32)state->mpu.bdiode << 12)) >> 2;
+	state->last_temp = temp;
+	DBG("  temp: %d.%03d\n", FIX32TOPRINT(temp));
+
+	/* Check tmax, increment overtemp if we are there. At tmax+8, we go
+	 * full blown immediately and try to trigger a shutdown
+	 */
+	if (temp >= ((state->mpu.tmax + 8) << 16)) {
+		printk(KERN_WARNING "Warning ! CPU %d temperature way above maximum (%d) !\n",
+		       state->index, temp >> 16);
+		state->overtemp = CPU_MAX_OVERTEMP;
+	} else if (temp > (state->mpu.tmax << 16))
+		state->overtemp++;
+	else
+		state->overtemp = 0;
+	if (state->overtemp >= CPU_MAX_OVERTEMP)
+		critical_state = 1;
+	if (state->overtemp > 0) {
+		state->rpm = state->mpu.rmaxn_exhaust_fan;
+		state->intake_rpm = intake = state->mpu.rmaxn_intake_fan;
+		goto do_set_fans;
+	}
+	
+	/* Scale other sensor values according to fixed scales
+	 * obtained in Darwin and calculate power from I and V
+	 */
+	state->voltage = voltage *= ADC_CPU_VOLTAGE_SCALE;
+	state->current_a = current_a *= ADC_CPU_CURRENT_SCALE;
+	power = (((u64)current_a) * ((u64)voltage)) >> 16;
+
+	/* Calculate power target value (could be done once for all)
+	 * and convert to a 16.16 fp number
+	 */
+	power_target = ((u32)(state->mpu.pmaxh - state->mpu.padjmax)) << 16;
+
+	DBG("  current: %d.%03d, voltage: %d.%03d\n",
+	    FIX32TOPRINT(current_a), FIX32TOPRINT(voltage));
+	DBG("  power: %d.%03d W, target: %d.%03d, error: %d.%03d\n", FIX32TOPRINT(power),
+	    FIX32TOPRINT(power_target), FIX32TOPRINT(power_target - power));
+
+	/* Store temperature and power in history array */
+	state->cur_temp = (state->cur_temp + 1) % CPU_TEMP_HISTORY_SIZE;
+	state->temp_history[state->cur_temp] = temp;
+	state->cur_power = (state->cur_power + 1) % state->count_power;
+	state->power_history[state->cur_power] = power;
+	state->error_history[state->cur_power] = power_target - power;
+	
+	/* If first loop, fill the history table */
+	if (state->first) {
+		for (i = 0; i < (state->count_power - 1); i++) {
+			state->cur_power = (state->cur_power + 1) % state->count_power;
+			state->power_history[state->cur_power] = power;
+			state->error_history[state->cur_power] = power_target - power;
+		}
+		for (i = 0; i < (CPU_TEMP_HISTORY_SIZE - 1); i++) {
+			state->cur_temp = (state->cur_temp + 1) % CPU_TEMP_HISTORY_SIZE;
+			state->temp_history[state->cur_temp] = temp;			
+		}
+		state->first = 0;
+	}
+
+	/* Calculate the integral term normally based on the "power" values */
+	sum = 0;
+	integral = 0;
+	for (i = 0; i < state->count_power; i++)
+		integral += state->error_history[i];
+	integral *= CPU_PID_INTERVAL;
+	DBG("  integral: %08x\n", integral);
+
+	/* Calculate the adjusted input (sense value).
+	 *   G_r is 12.20
+	 *   integ is 16.16
+	 *   so the result is 28.36
+	 *
+	 * input target is mpu.ttarget, input max is mpu.tmax
+	 */
+	integ_p = ((s64)state->mpu.pid_gr) * (s64)integral;
+	DBG("   integ_p: %d\n", (int)(deriv_p >> 36));
+	sval = (state->mpu.tmax << 16) - ((integ_p >> 20) & 0xffffffff);
+	adj_in_target = (state->mpu.ttarget << 16);
+	if (adj_in_target > sval)
+		adj_in_target = sval;
+	DBG("   adj_in_target: %d.%03d, ttarget: %d\n", FIX32TOPRINT(adj_in_target),
+	    state->mpu.ttarget);
+
+	/* Calculate the derivative term */
+	derivative = state->temp_history[state->cur_temp] -
+		state->temp_history[(state->cur_temp + CPU_TEMP_HISTORY_SIZE - 1)
+				    % CPU_TEMP_HISTORY_SIZE];
+	derivative /= CPU_PID_INTERVAL;
+	deriv_p = ((s64)state->mpu.pid_gd) * (s64)derivative;
+	DBG("   deriv_p: %d\n", (int)(deriv_p >> 36));
+	sum += deriv_p;
+
+	/* Calculate the proportional term */
+	proportional = temp - adj_in_target;
+	prop_p = ((s64)state->mpu.pid_gp) * (s64)proportional;
+	DBG("   prop_p: %d\n", (int)(prop_p >> 36));
+	sum += prop_p;
+
+	/* Scale sum */
+	sum >>= 36;
+
+	DBG("   sum: %d\n", (int)sum);
+	state->rpm += (s32)sum;
+
+	if (state->rpm < state->mpu.rminn_exhaust_fan)
+		state->rpm = state->mpu.rminn_exhaust_fan;
+	if (state->rpm > state->mpu.rmaxn_exhaust_fan)
+		state->rpm = state->mpu.rmaxn_exhaust_fan;
+
+	intake = (state->rpm * CPU_INTAKE_SCALE) >> 16;
+	if (intake < state->mpu.rminn_intake_fan)
+		intake = state->mpu.rminn_intake_fan;
+	if (intake > state->mpu.rmaxn_intake_fan)
+		intake = state->mpu.rmaxn_intake_fan;
+	state->intake_rpm = intake;
+
+ do_set_fans:
+	DBG("** CPU %d RPM: %d Ex, %d In, overtemp: %d\n",
+	    state->index, (int)state->rpm, intake, state->overtemp);
+
+	/* We should check for errors, shouldn't we ? But then, what
+	 * do we do once the error occurs ? For FCU notified fan
+	 * failures (-EFAULT) we probably want to notify userland
+	 * some way...
+	 */
+	if (state->index == 0) {
+		set_rpm_fan(CPUA_INTAKE_FAN_RPM_ID, intake);
+		set_rpm_fan(CPUA_EXHAUST_FAN_RPM_ID, state->rpm);
+	} else {
+		set_rpm_fan(CPUB_INTAKE_FAN_RPM_ID, intake);
+		set_rpm_fan(CPUB_EXHAUST_FAN_RPM_ID, state->rpm);
+	}
+}
+
+/*
+ * Initialize the state structure for one CPU control loop
+ */
+static int init_cpu_state(struct cpu_pid_state *state, int index)
+{
+	state->index = index;
+	state->first = 1;
+	state->rpm = 1000;
+	state->overtemp = 0;
+
+	if (index == 0)
+		state->monitor = attach_i2c_chip(SUPPLY_MONITOR_ID, "CPU0_monitor");
+	else if (index == 1)
+		state->monitor = attach_i2c_chip(SUPPLY_MONITORB_ID, "CPU1_monitor");
+	if (state->monitor == NULL)
+		goto fail;
+
+	if (read_eeprom(index, &state->mpu))
+		goto fail;
+
+	state->count_power = state->mpu.tguardband;
+	if (state->count_power > CPU_POWER_HISTORY_SIZE) {
+		printk(KERN_WARNING "Warning ! too many power history slots\n");
+		state->count_power = CPU_POWER_HISTORY_SIZE;
+	}
+	DBG("CPU %d Using %d power history entries\n", index, state->count_power);
+
+	if (index == 0) {
+		device_create_file(&of_dev->dev, &dev_attr_cpu0_temperature);
+		device_create_file(&of_dev->dev, &dev_attr_cpu0_voltage);
+		device_create_file(&of_dev->dev, &dev_attr_cpu0_current);
+		device_create_file(&of_dev->dev, &dev_attr_cpu0_exhaust_fan_rpm);
+		device_create_file(&of_dev->dev, &dev_attr_cpu0_intake_fan_rpm);
+	} else {
+		device_create_file(&of_dev->dev, &dev_attr_cpu1_temperature);
+		device_create_file(&of_dev->dev, &dev_attr_cpu1_voltage);
+		device_create_file(&of_dev->dev, &dev_attr_cpu1_current);
+		device_create_file(&of_dev->dev, &dev_attr_cpu1_exhaust_fan_rpm);
+		device_create_file(&of_dev->dev, &dev_attr_cpu1_intake_fan_rpm);
+	}
+
+	return 0;
+ fail:
+	if (state->monitor)
+		detach_i2c_chip(state->monitor);
+	state->monitor = NULL;
+	
+	return -ENODEV;
+}
+
+/*
+ * Dispose of the state data for one CPU control loop
+ */
+static void dispose_cpu_state(struct cpu_pid_state *state)
+{
+	if (state->monitor == NULL)
+		return;
+
+	if (state->index == 0) {
+		device_remove_file(&of_dev->dev, &dev_attr_cpu0_temperature);
+		device_remove_file(&of_dev->dev, &dev_attr_cpu0_voltage);
+		device_remove_file(&of_dev->dev, &dev_attr_cpu0_current);
+		device_remove_file(&of_dev->dev, &dev_attr_cpu0_exhaust_fan_rpm);
+		device_remove_file(&of_dev->dev, &dev_attr_cpu0_intake_fan_rpm);
+	} else {
+		device_remove_file(&of_dev->dev, &dev_attr_cpu1_temperature);
+		device_remove_file(&of_dev->dev, &dev_attr_cpu1_voltage);
+		device_remove_file(&of_dev->dev, &dev_attr_cpu1_current);
+		device_remove_file(&of_dev->dev, &dev_attr_cpu1_exhaust_fan_rpm);
+		device_remove_file(&of_dev->dev, &dev_attr_cpu1_intake_fan_rpm);
+	}
+
+	detach_i2c_chip(state->monitor);
+	state->monitor = NULL;
+}
+
+/*
+ * Motherboard backside & U3 heatsink fan control loop
+ */
+static void do_monitor_backside(struct backside_pid_state *state)
+{
+	s32 temp, integral, derivative;
+	s64 integ_p, deriv_p, prop_p, sum; 
+	int i, rc;
+
+	if (--state->ticks != 0)
+		return;
+	state->ticks = BACKSIDE_PID_INTERVAL;
+
+	DBG("backside:\n");
+
+	/* Check fan status */
+	rc = get_pwm_fan(BACKSIDE_FAN_PWM_ID);
+	if (rc < 0) {
+		printk(KERN_WARNING "Error %d reading backside fan !\n", rc);
+		/* XXX What do we do now ? */
+	} else
+		state->pwm = rc;
+	DBG("  current pwm: %d\n", state->pwm);
+
+	/* Get some sensor readings */
+	temp = i2c_smbus_read_byte_data(state->monitor, MAX6690_EXT_TEMP) << 16;
+	state->last_temp = temp;
+	DBG("  temp: %d.%03d, target: %d.%03d\n", FIX32TOPRINT(temp),
+	    FIX32TOPRINT(BACKSIDE_PID_INPUT_TARGET));
+
+	/* Store temperature and error in history array */
+	state->cur_sample = (state->cur_sample + 1) % BACKSIDE_PID_HISTORY_SIZE;
+	state->sample_history[state->cur_sample] = temp;
+	state->error_history[state->cur_sample] = temp - BACKSIDE_PID_INPUT_TARGET;
+	
+	/* If first loop, fill the history table */
+	if (state->first) {
+		for (i = 0; i < (BACKSIDE_PID_HISTORY_SIZE - 1); i++) {
+			state->cur_sample = (state->cur_sample + 1) %
+				BACKSIDE_PID_HISTORY_SIZE;
+			state->sample_history[state->cur_sample] = temp;
+			state->error_history[state->cur_sample] =
+				temp - BACKSIDE_PID_INPUT_TARGET;
+		}
+		state->first = 0;
+	}
+
+	/* Calculate the integral term */
+	sum = 0;
+	integral = 0;
+	for (i = 0; i < BACKSIDE_PID_HISTORY_SIZE; i++)
+		integral += state->error_history[i];
+	integral *= BACKSIDE_PID_INTERVAL;
+	DBG("  integral: %08x\n", integral);
+	integ_p = ((s64)BACKSIDE_PID_G_r) * (s64)integral;
+	DBG("   integ_p: %d\n", (int)(integ_p >> 36));
+	sum += integ_p;
+
+	/* Calculate the derivative term */
+	derivative = state->error_history[state->cur_sample] -
+		state->error_history[(state->cur_sample + BACKSIDE_PID_HISTORY_SIZE - 1)
+				    % BACKSIDE_PID_HISTORY_SIZE];
+	derivative /= BACKSIDE_PID_INTERVAL;
+	deriv_p = ((s64)BACKSIDE_PID_G_d) * (s64)derivative;
+	DBG("   deriv_p: %d\n", (int)(deriv_p >> 36));
+	sum += deriv_p;
+
+	/* Calculate the proportional term */
+	prop_p = ((s64)BACKSIDE_PID_G_p) * (s64)(state->error_history[state->cur_sample]);
+	DBG("   prop_p: %d\n", (int)(prop_p >> 36));
+	sum += prop_p;
+
+	/* Scale sum */
+	sum >>= 36;
+
+	DBG("   sum: %d\n", (int)sum);
+	state->pwm += (s32)sum;
+	if (state->pwm < BACKSIDE_PID_OUTPUT_MIN)
+		state->pwm = BACKSIDE_PID_OUTPUT_MIN;
+	if (state->pwm > BACKSIDE_PID_OUTPUT_MAX)
+		state->pwm = BACKSIDE_PID_OUTPUT_MAX;
+
+	DBG("** BACKSIDE PWM: %d\n", (int)state->pwm);
+	set_pwm_fan(BACKSIDE_FAN_PWM_ID, state->pwm);
+}
+
+/*
+ * Initialize the state structure for the backside fan control loop
+ */
+static int init_backside_state(struct backside_pid_state *state)
+{
+	state->ticks = 1;
+	state->first = 1;
+	state->pwm = 50;
+
+	state->monitor = attach_i2c_chip(BACKSIDE_MAX_ID, "backside_temp");
+	if (state->monitor == NULL)
+		return -ENODEV;
+
+	device_create_file(&of_dev->dev, &dev_attr_backside_temperature);
+	device_create_file(&of_dev->dev, &dev_attr_backside_fan_pwm);
+
+	return 0;
+}
+
+/*
+ * Dispose of the state data for the backside control loop
+ */
+static void dispose_backside_state(struct backside_pid_state *state)
+{
+	if (state->monitor == NULL)
+		return;
+
+	device_remove_file(&of_dev->dev, &dev_attr_backside_temperature);
+	device_remove_file(&of_dev->dev, &dev_attr_backside_fan_pwm);
+
+	detach_i2c_chip(state->monitor);
+	state->monitor = NULL;
+}
+ 
+/*
+ * Drives bay fan control loop
+ */
+static void do_monitor_drives(struct drives_pid_state *state)
+{
+	s32 temp, integral, derivative;
+	s64 integ_p, deriv_p, prop_p, sum; 
+	int i, rc;
+
+	if (--state->ticks != 0)
+		return;
+	state->ticks = DRIVES_PID_INTERVAL;
+
+	DBG("drives:\n");
+
+	/* Check fan status */
+	rc = get_rpm_fan(DRIVES_FAN_RPM_ID, !RPM_PID_USE_ACTUAL_SPEED);
+	if (rc < 0) {
+		printk(KERN_WARNING "Error %d reading drives fan !\n", rc);
+		/* XXX What do we do now ? */
+	} else
+		state->rpm = rc;
+	DBG("  current rpm: %d\n", state->rpm);
+
+	/* Get some sensor readings */
+	temp = le16_to_cpu(i2c_smbus_read_word_data(state->monitor, DS1775_TEMP)) << 8;
+	state->last_temp = temp;
+	DBG("  temp: %d.%03d, target: %d.%03d\n", FIX32TOPRINT(temp),
+	    FIX32TOPRINT(DRIVES_PID_INPUT_TARGET));
+
+	/* Store temperature and error in history array */
+	state->cur_sample = (state->cur_sample + 1) % DRIVES_PID_HISTORY_SIZE;
+	state->sample_history[state->cur_sample] = temp;
+	state->error_history[state->cur_sample] = temp - DRIVES_PID_INPUT_TARGET;
+	
+	/* If first loop, fill the history table */
+	if (state->first) {
+		for (i = 0; i < (DRIVES_PID_HISTORY_SIZE - 1); i++) {
+			state->cur_sample = (state->cur_sample + 1) %
+				DRIVES_PID_HISTORY_SIZE;
+			state->sample_history[state->cur_sample] = temp;
+			state->error_history[state->cur_sample] =
+				temp - DRIVES_PID_INPUT_TARGET;
+		}
+		state->first = 0;
+	}
+
+	/* Calculate the integral term */
+	sum = 0;
+	integral = 0;
+	for (i = 0; i < DRIVES_PID_HISTORY_SIZE; i++)
+		integral += state->error_history[i];
+	integral *= DRIVES_PID_INTERVAL;
+	DBG("  integral: %08x\n", integral);
+	integ_p = ((s64)DRIVES_PID_G_r) * (s64)integral;
+	DBG("   integ_p: %d\n", (int)(integ_p >> 36));
+	sum += integ_p;
+
+	/* Calculate the derivative term */
+	derivative = state->error_history[state->cur_sample] -
+		state->error_history[(state->cur_sample + DRIVES_PID_HISTORY_SIZE - 1)
+				    % DRIVES_PID_HISTORY_SIZE];
+	derivative /= DRIVES_PID_INTERVAL;
+	deriv_p = ((s64)DRIVES_PID_G_d) * (s64)derivative;
+	DBG("   deriv_p: %d\n", (int)(deriv_p >> 36));
+	sum += deriv_p;
+
+	/* Calculate the proportional term */
+	prop_p = ((s64)DRIVES_PID_G_p) * (s64)(state->error_history[state->cur_sample]);
+	DBG("   prop_p: %d\n", (int)(prop_p >> 36));
+	sum += prop_p;
+
+	/* Scale sum */
+	sum >>= 36;
+
+	DBG("   sum: %d\n", (int)sum);
+	state->rpm += (s32)sum;
+	if (state->rpm < DRIVES_PID_OUTPUT_MIN)
+		state->rpm = DRIVES_PID_OUTPUT_MIN;
+	if (state->rpm > DRIVES_PID_OUTPUT_MAX)
+		state->rpm = DRIVES_PID_OUTPUT_MAX;
+
+	DBG("** DRIVES RPM: %d\n", (int)state->rpm);
+	set_rpm_fan(DRIVES_FAN_RPM_ID, state->rpm);
+}
+
+/*
+ * Initialize the state structure for the drives bay fan control loop
+ */
+static int init_drives_state(struct drives_pid_state *state)
+{
+	state->ticks = 1;
+	state->first = 1;
+	state->rpm = 1000;
+
+	state->monitor = attach_i2c_chip(DRIVES_DALLAS_ID, "drives_temp");
+	if (state->monitor == NULL)
+		return -ENODEV;
+
+	device_create_file(&of_dev->dev, &dev_attr_drives_temperature);
+	device_create_file(&of_dev->dev, &dev_attr_drives_fan_rpm);
+
+	return 0;
+}
+
+/*
+ * Dispose of the state data for the drives control loop
+ */
+static void dispose_drives_state(struct drives_pid_state *state)
+{
+	if (state->monitor == NULL)
+		return;
+
+	device_remove_file(&of_dev->dev, &dev_attr_drives_temperature);
+	device_remove_file(&of_dev->dev, &dev_attr_drives_fan_rpm);
+
+	detach_i2c_chip(state->monitor);
+	state->monitor = NULL;
+}
+
+static int call_critical_overtemp(void)
+{
+	char *argv[] = { critical_overtemp_path, NULL };
+	static char *envp[] = { "HOME=/",
+				"TERM=linux",
+				"PATH=/sbin:/usr/sbin:/bin:/usr/bin",
+				NULL };
+
+	return call_usermodehelper(critical_overtemp_path, argv, envp, 0);
+}
+
+
+/*
+ * Here's the kernel thread that calls the various control loops
+ */
+static int main_control_loop(void *x)
+{
+	daemonize("kfand");
+
+	DBG("main_control_loop started\n");
+
+	/* Set the PCI fan once for now */
+	set_pwm_fan(SLOTS_FAN_PWM_ID, SLOTS_FAN_DEFAULT_PWM);
+
+	while (state == state_attached) {
+		unsigned long elapsed, start;
+
+		start = jiffies;
+
+		down(&driver_lock);
+		do_monitor_cpu(&cpu_state[0]);
+		if (cpu_state[1].monitor != NULL)
+			do_monitor_cpu(&cpu_state[1]);
+		do_monitor_backside(&backside_state);
+		do_monitor_drives(&drives_state);
+		up(&driver_lock);
+
+		if (critical_state == 1) {
+			printk(KERN_WARNING "Temperature control detected a critical condition\n");
+			printk(KERN_WARNING "Attempting to shut down...\n");
+			if (call_critical_overtemp()) {
+				printk(KERN_WARNING "Can't call %s, power off now!\n",
+				       critical_overtemp_path);
+				machine_power_off();
+			}
+		}
+		if (critical_state > 0)
+			critical_state++;
+		if (critical_state > MAX_CRITICAL_STATE) {
+			printk(KERN_WARNING "Shutdown timed out, power off now !\n");
+			machine_power_off();
+		}
+
+		// FIXME: Deal with signals
+		set_current_state(TASK_INTERRUPTIBLE);
+		elapsed = jiffies - start;
+		if (elapsed < HZ)
+			schedule_timeout(HZ - elapsed);
+	}
+
+	DBG("main_control_loop ended\n");
+
+	ctrl_task = 0;
+	complete_and_exit(&ctrl_complete, 0);
+}
+
+/*
+ * Dispose the control loops when tearing down
+ */
+static void dispose_control_loops(void)
+{
+	dispose_cpu_state(&cpu_state[0]);
+	dispose_cpu_state(&cpu_state[1]);
+
+	dispose_backside_state(&backside_state);
+	dispose_drives_state(&drives_state);
+}
+
+/*
+ * Create the control loops. U3-0 i2c bus is up, so we can now
+ * get to the various sensors
+ */
+static int create_control_loops(void)
+{
+	struct device_node *np;
+
+	/* Count CPUs from the device-tree, we don't care how many are
+	 * actually used by Linux
+	 */
+	cpu_count = 0;
+	for (np = NULL; NULL != (np = of_find_node_by_type(np, "cpu"));)
+		cpu_count++;
+
+	DBG("counted %d CPUs in the device-tree\n", cpu_count);
+
+	/* Create control loops for everything. If any fail, everything
+	 * fails
+	 */
+	if (init_cpu_state(&cpu_state[0], 0))
+		goto fail;
+	if (cpu_count > 1 && init_cpu_state(&cpu_state[1], 1))
+		goto fail;
+	if (init_backside_state(&backside_state))
+		goto fail;
+	if (init_drives_state(&drives_state))
+		goto fail;
+
+	DBG("all control loops up !\n");
+
+	return 0;
+	
+ fail:
+	DBG("failure creating control loops, disposing\n");
+
+	dispose_control_loops();
+
+	return -ENODEV;
+}
+
+/*
+ * Start the control loops after everything is up, that is create
+ * the thread that will make them run
+ */
+static void start_control_loops(void)
+{
+	init_completion(&ctrl_complete);
+
+	ctrl_task = kernel_thread(main_control_loop, NULL, SIGCHLD | CLONE_KERNEL);
+}
+
+/*
+ * Stop the control loops when tearing down
+ */
+static void stop_control_loops(void)
+{
+	if (ctrl_task != 0)
+		wait_for_completion(&ctrl_complete);
+}
+
+/*
+ * Attach to the i2c FCU after detecting U3-1 bus
+ */
+static int attach_fcu(void)
+{
+	fcu = attach_i2c_chip(FAN_CTRLER_ID, "fcu");
+	if (fcu == NULL)
+		return -ENODEV;
+
+	DBG("FCU attached\n");
+
+	return 0;
+}
+
+/*
+ * Detach from the i2c FCU when tearing down
+ */
+static void detach_fcu(void)
+{
+	if (fcu)
+		detach_i2c_chip(fcu);
+	fcu = NULL;
+}
+
+/*
+ * Attach to the i2c controller. We probe the various chips based
+ * on the device-tree nodes and build everything for the driver to
+ * run, we then kick the driver monitoring thread
+ */
+static int therm_pm72_attach(struct i2c_adapter *adapter)
+{
+	down(&driver_lock);
+
+	/* Check state */
+	if (state == state_detached)
+		state = state_attaching;
+	if (state != state_attaching) {
+		up(&driver_lock);
+		return 0;
+	}
+
+	/* Check if we are looking for one of these */
+	if (u3_0 == NULL && !strcmp(adapter->name, "u3 0")) {
+		u3_0 = adapter;
+		DBG("found U3-0, creating control loops\n");
+		if (create_control_loops())
+			u3_0 = NULL;
+	} else if (u3_1 == NULL && !strcmp(adapter->name, "u3 1")) {
+		u3_1 = adapter;
+		DBG("found U3-1, attaching FCU\n");
+		if (attach_fcu())
+			u3_1 = NULL;
+	}
+	/* We got all we need, start control loops */
+	if (u3_0 != NULL && u3_1 != NULL) {
+		DBG("everything up, starting control loops\n");
+		state = state_attached;
+		start_control_loops();
+	}
+	up(&driver_lock);
+
+	return 0;
+}
+
+/*
+ * Called on every adapter when the driver or the i2c controller
+ * is going away.
+ */
+static int therm_pm72_detach(struct i2c_adapter *adapter)
+{
+	down(&driver_lock);
+
+	if (state != state_detached)
+		state = state_detaching;
+
+	/* Stop control loops if any */
+	DBG("stopping control loops\n");
+	up(&driver_lock);
+	stop_control_loops();
+	down(&driver_lock);
+
+	if (u3_0 != NULL && !strcmp(adapter->name, "u3 0")) {
+		DBG("lost U3-0, disposing control loops\n");
+		dispose_control_loops();
+		u3_0 = NULL;
+	}
+	
+	if (u3_1 != NULL && !strcmp(adapter->name, "u3 1")) {
+		DBG("lost U3-1, detaching FCU\n");
+		detach_fcu();
+		u3_1 = NULL;
+	}
+	if (u3_0 == NULL && u3_1 == NULL)
+		state = state_detached;
+
+	up(&driver_lock);
+
+	return 0;
+}
+
+static int fcu_of_probe(struct of_device* dev, const struct of_match *match)
+{
+	int rc;
+
+	state = state_detached;
+
+	rc = i2c_add_driver(&therm_pm72_driver);
+	if (rc < 0)
+		return rc;
+	return 0;
+}
+
+static int fcu_of_remove(struct of_device* dev)
+{
+	i2c_del_driver(&therm_pm72_driver);
+
+	return 0;
+}
+
+static struct of_match fcu_of_match[] = 
+{
+	{
+	.name 		= OF_ANY_MATCH,
+	.type		= "fcu",
+	.compatible	= OF_ANY_MATCH
+	},
+	{},
+};
+
+static struct of_platform_driver fcu_of_platform_driver = 
+{
+	.name 		= "temperature",
+	.match_table	= fcu_of_match,
+	.probe		= fcu_of_probe,
+	.remove		= fcu_of_remove
+};
+
+/*
+ * Check machine type, attach to i2c controller
+ */
+static int __init therm_pm72_init(void)
+{
+	struct device_node *np;
+
+	if (!machine_is_compatible("PowerMac7,2"))
+	    	return -ENODEV;
+
+	printk(KERN_INFO "PowerMac G5 Thermal control driver %s\n", VERSION);
+
+	np = of_find_node_by_type(NULL, "fcu");
+	if (np == NULL) {
+		printk(KERN_ERR "Can't find FCU in device-tree !\n");
+		return -ENODEV;
+	}
+	of_dev = of_platform_device_create(np, "temperature");
+	if (of_dev == NULL) {
+		printk(KERN_ERR "Can't register FCU platform device !\n");
+		return -ENODEV;
+	}
+
+	of_register_driver(&fcu_of_platform_driver);
+	
+	return 0;
+}
+
+static void __exit therm_pm72_exit(void)
+{
+	of_unregister_driver(&fcu_of_platform_driver);
+
+	if (of_dev)
+		of_device_unregister(of_dev);
+}
+
+module_init(therm_pm72_init);
+module_exit(therm_pm72_exit);
+
+MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
+MODULE_DESCRIPTION("Driver for Apple's PowerMac7,2 G5 thermal control");
+MODULE_LICENSE("GPL");
+

drivers/macintosh/therm_pm72.h

+#ifndef __THERM_PMAC_7_2_H__
+#define __THERM_PMAC_7_2_H__
+
+typedef unsigned short fu16;
+typedef int fs32;
+typedef short fs16;
+
+struct mpu_data
+{
+	u8	signature;		/* 0x00 - EEPROM sig. */
+	u8	bytes_used;		/* 0x01 - Bytes used in eeprom (160 ?) */
+	u8	size;			/* 0x02 - EEPROM size (256 ?) */
+	u8	version;		/* 0x03 - EEPROM version */
+	u32	data_revision;		/* 0x04 - Dataset revision */
+	u8	processor_bin_code[3];	/* 0x08 - Processor BIN code */
+	u8	bin_code_expansion;	/* 0x0b - ??? (padding ?) */
+	u8	processor_num;		/* 0x0c - Number of CPUs on this MPU */
+	u8	input_mul_bus_div;	/* 0x0d - Clock input multiplier/bus divider */
+	u8	reserved1[2];		/* 0x0e - */
+	u32	input_clk_freq_high;	/* 0x10 - Input clock frequency high */
+	u8	cpu_nb_target_cycles;	/* 0x14 - ??? */
+	u8	cpu_statlat;		/* 0x15 - ??? */
+	u8	cpu_snooplat;		/* 0x16 - ??? */
+	u8	cpu_snoopacc;		/* 0x17 - ??? */
+	u8	nb_paamwin;		/* 0x18 - ??? */
+	u8	nb_statlat;		/* 0x19 - ??? */
+	u8	nb_snooplat;		/* 0x1a - ??? */
+	u8	nb_snoopwin;		/* 0x1b - ??? */
+	u8	api_bus_mode;		/* 0x1c - ??? */
+	u8	reserved2[3];		/* 0x1d - */
+	u32	input_clk_freq_low;	/* 0x20 - Input clock frequency low */
+	u8	processor_card_slot;	/* 0x24 - Processor card slot number */
+	u8	reserved3[2];		/* 0x25 - */
+	u8	padjmax;       		/* 0x27 - Max power adjustment (Not in OF!) */
+	u8	ttarget;		/* 0x28 - Target temperature */
+	u8	tmax;			/* 0x29 - Max temperature */
+	u8	pmaxh;			/* 0x2a - Max power */
+	u8	tguardband;		/* 0x2b - Guardband temp ??? Hist. len in OSX */
+	fs32	pid_gp;			/* 0x2c - PID proportional gain */
+	fs32	pid_gr;			/* 0x30 - PID reset gain */
+	fs32	pid_gd;			/* 0x34 - PID derivative gain */
+	fu16	voph;			/* 0x38 - Vop High */
+	fu16	vopl;			/* 0x3a - Vop Low */
+	fs16	nactual_die;		/* 0x3c - nActual Die */
+	fs16	nactual_heatsink;	/* 0x3e - nActual Heatsink */
+	fs16	nactual_system;		/* 0x40 - nActual System */
+	u16	calibration_flags;	/* 0x42 - Calibration flags */
+	fu16	mdiode;			/* 0x44 - Diode M value (scaling factor) */
+	fs16	bdiode;			/* 0x46 - Diode B value (offset) */
+	fs32	theta_heat_sink;	/* 0x48 - Theta heat sink */
+	u16	rminn_intake_fan;	/* 0x4c - Intake fan min RPM */
+	u16	rmaxn_intake_fan;	/* 0x4e - Intake fan max RPM */
+	u16	rminn_exhaust_fan;	/* 0x50 - Exhaust fan min RPM */
+	u16	rmaxn_exhaust_fan;	/* 0x52 - Exhaust fan max RPM */
+	u8	processor_part_num[8];	/* 0x54 - Processor part number */
+	u32	processor_lot_num;	/* 0x5c - Processor lot number */
+	u8	orig_card_sernum[0x10];	/* 0x60 - Card original serial number */
+	u8	curr_card_sernum[0x10];	/* 0x70 - Card current serial number */
+	u8	mlb_sernum[0x18];	/* 0x80 - MLB serial number */
+	u32	checksum1;		/* 0x98 - */
+	u32	checksum2;		/* 0x9c - */	
+}; /* Total size = 0xa0 */
+
+/* Display a 16.16 fixed point value */
+#define FIX32TOPRINT(f)	((f) >> 16),((((f) & 0xffff) * 1000) >> 16)
+
+/*
+ * Maximum number of seconds to be in critical state (after a
+ * normal shutdown attempt). If the machine isn't down after
+ * this counter elapses, we force an immediate machine power
+ * off.
+ */
+#define MAX_CRITICAL_STATE			30
+static char * critical_overtemp_path = "/sbin/critical_overtemp";
+
+/*
+ * This option is "weird" :) Basically, if you define this to 1
+ * the control loop for the RPMs fans (not PWMs) will apply the
+ * correction factor obtained from the PID to the _actual_ RPM
+ * speed read from the FCU.
+ * If you define the below constant to 0, then it will be
+ * applied to the setpoint RPM speed, that is basically the
+ * speed we proviously "asked" for.
+ *
+ * I'm not sure which of these Apple's algorithm is supposed
+ * to use
+ */
+#define RPM_PID_USE_ACTUAL_SPEED		1
+
+/*
+ * i2c IDs. Currently, we hard code those and assume that
+ * the FCU is on U3 bus 1 while all sensors are on U3 bus
+ * 0. This appear to be safe enough for this first version
+ * of the driver, though I would accept any clean patch
+ * doing a better use of the device-tree without turning the
+ * while i2c registration mecanism into a racy mess
+ */
+#define FAN_CTRLER_ID		0x15e
+#define SUPPLY_MONITOR_ID      	0x58
+#define SUPPLY_MONITORB_ID     	0x5a
+#define DRIVES_DALLAS_ID	0x94
+#define BACKSIDE_MAX_ID		0x98
+
+/*
+ * Some MAX6690 & DS1775 register definitions
+ */
+#define MAX6690_INT_TEMP	0
+#define MAX6690_EXT_TEMP	1
+#define DS1775_TEMP		0
+
+/*
+ * Scaling factors for the AD7417 ADC converters (except
+ * for the CPU diode which is obtained from the EEPROM).
+ * Those values are obtained from the property list of
+ * the darwin driver
+ */
+#define ADC_12V_CURRENT_SCALE	0x0320	/* _AD2 */
+#define ADC_CPU_VOLTAGE_SCALE	0x00a0	/* _AD3 */
+#define ADC_CPU_CURRENT_SCALE	0x1f40	/* _AD4 */
+
+/*
+ * PID factors for the U3/Backside fan control loop
+ */
+#define BACKSIDE_FAN_PWM_ID		1
+#define BACKSIDE_PID_G_d		0x02800000
+#define BACKSIDE_PID_G_p		0x00500000
+#define BACKSIDE_PID_G_r		0x00000000
+#define BACKSIDE_PID_INPUT_TARGET	0x00410000
+#define BACKSIDE_PID_INTERVAL		5
+#define BACKSIDE_PID_OUTPUT_MAX		100
+#define BACKSIDE_PID_OUTPUT_MIN		20
+#define BACKSIDE_PID_HISTORY_SIZE	2
+
+struct backside_pid_state
+{
+	int			ticks;
+	struct i2c_client *	monitor;
+	s32		       	sample_history[BACKSIDE_PID_HISTORY_SIZE];
+	s32			error_history[BACKSIDE_PID_HISTORY_SIZE];
+	int			cur_sample;
+	s32			last_temp;
+	int			pwm;
+	int			first;
+};
+
+/*
+ * PID factors for the Drive Bay fan control loop
+ */
+#define DRIVES_FAN_RPM_ID      		2
+#define DRIVES_PID_G_d			0x01e00000
+#define DRIVES_PID_G_p			0x00500000
+#define DRIVES_PID_G_r			0x00000000
+#define DRIVES_PID_INPUT_TARGET		0x00280000
+#define DRIVES_PID_INTERVAL    		5
+#define DRIVES_PID_OUTPUT_MAX		4000
+#define DRIVES_PID_OUTPUT_MIN		300
+#define DRIVES_PID_HISTORY_SIZE		2
+
+struct drives_pid_state
+{
+	int			ticks;
+	struct i2c_client *	monitor;
+	s32	       		sample_history[BACKSIDE_PID_HISTORY_SIZE];
+	s32			error_history[BACKSIDE_PID_HISTORY_SIZE];
+	int			cur_sample;
+	s32			last_temp;
+	int			rpm;
+	int			first;
+};
+
+#define SLOTS_FAN_PWM_ID       		2
+#define	SLOTS_FAN_DEFAULT_PWM		50 /* Do better here ! */
+
+/*
+ * IDs in Darwin for the sensors & fans
+ *
+ * CPU A AD7417_TEMP	10	(CPU A ambient temperature)
+ * CPU A AD7417_AD1	11	(CPU A diode temperature)
+ * CPU A AD7417_AD2	12	(CPU A 12V current)
+ * CPU A AD7417_AD3	13	(CPU A voltage)
+ * CPU A AD7417_AD4	14	(CPU A current)
+ *
+ * CPU A FAKE POWER	48	(I_V_inputs: 13, 14)
+ *
+ * CPU B AD7417_TEMP	15	(CPU B ambient temperature)
+ * CPU B AD7417_AD1	16	(CPU B diode temperature)
+ * CPU B AD7417_AD2	17	(CPU B 12V current)
+ * CPU B AD7417_AD3	18	(CPU B voltage)
+ * CPU B AD7417_AD4	19	(CPU B current)
+ *
+ * CPU B FAKE POWER	49	(I_V_inputs: 18, 19)
+ */
+
+#define CPUA_INTAKE_FAN_RPM_ID		3
+#define CPUA_EXHAUST_FAN_RPM_ID		4
+#define CPUB_INTAKE_FAN_RPM_ID		5
+#define CPUB_EXHAUST_FAN_RPM_ID		6
+
+#define CPU_INTAKE_SCALE		0x0000f852
+#define CPU_TEMP_HISTORY_SIZE		2
+#define CPU_POWER_HISTORY_SIZE		10
+#define CPU_PID_INTERVAL		1
+#define CPU_MAX_OVERTEMP		30
+
+struct cpu_pid_state
+{
+	int			index;
+	struct i2c_client *	monitor;
+	struct mpu_data		mpu;
+	int			overtemp;
+	s32	       		temp_history[CPU_TEMP_HISTORY_SIZE];
+	int			cur_temp;
+	s32			power_history[CPU_POWER_HISTORY_SIZE];
+	s32			error_history[CPU_POWER_HISTORY_SIZE];
+	int			cur_power;
+	int			count_power;
+	int			rpm;
+	int			intake_rpm;
+	s32			voltage;
+	s32			current_a;
+	s32			last_temp;
+	int			first;
+};
+
+/*
+ * Driver state
+ */
+enum {
+	state_detached,
+	state_attaching,
+	state_attached,
+	state_detaching,
+};
+
+
+#endif /* __THERM_PMAC_7_2_H__ */

drivers/macintosh/therm_windtunnel.c

+/* 
+ *   Creation Date: <2003/03/14 20:54:13 samuel>
+ *   Time-stamp: <2003/03/15 18:55:53 samuel>
+ *   
+ *	<therm_windtunnel.c>
+ *	
+ *	The G4 "windtunnel" has a single fan controlled by a
+ *	DS1775 fan controller and an ADM1030 thermostat.
+ *
+ *	The fan controller is equipped with a temperature sensor
+ *	which measures the case temperature. The ADM censor
+ *	measures the CPU temperature. This driver tunes the
+ *	behavior of the fan. It is based upon empirical observations
+ *	of the 'AppleFan' driver under OSX.
+ *
+ *	WARNING: This driver has only been testen on Apple's
+ *	1.25 MHz Dual G4 (March 03). Other machines might have
+ *	a different thermal design. It is tuned for a CPU
+ *	temperatur around 57 C.
+ *
+ *   Copyright (C) 2003 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 <linux/workqueue.h>
+#include <asm/prom.h>
+#include <asm/machdep.h>
+#include <asm/io.h>
+#include <asm/system.h>
+#include <asm/sections.h>
+
+MODULE_AUTHOR("Samuel Rydh <samuel@ibrium.se>");
+MODULE_DESCRIPTION("Apple G4 (windtunnel) fan driver");
+MODULE_LICENSE("GPL");
+
+#define LOG_TEMP		0			/* continously log temperature */
+
+/* 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 };
+static struct work_struct poll_work;
+
+I2C_CLIENT_INSMOD;
+
+#define I2C_DRIVERID_G4FAN	0x9001			/* fixme */
+
+#define THERMOSTAT_CLIENT_ID	1
+#define FAN_CLIENT_ID		2
+
+struct temp_range {
+	u8			high;			/* start the fan */
+	u8			low;			/* stop the fan */
+};
+struct apple_thermal_info {
+	u8			id;			/* implementation ID */
+	u8			fan_count;		/* number of fans */
+	u8			thermostat_count;	/* number of thermostats */
+	u8			unused[5];
+	struct temp_range	ranges[4];		/* temperature ranges (may be [])*/
+};
+
+static int do_detect( struct i2c_adapter *adapter, int addr, int kind);
+
+static struct {
+	struct i2c_client	*thermostat;
+	struct i2c_client	*fan;
+	int			error;
+	struct timer_list	timer;
+
+	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;
+
+static struct {
+	int			temp;
+	int			fan_setting;
+} fan_up_table[] = {
+	{ 0x0000, 11 },		/* min fan */
+	{ 0x3900, 8 },		/* 57.0 C */
+	{ 0x3a4a, 7 },		/* 58.3 C */
+	{ 0x3ad3, 6 },		/* 58.8 C */
+	{ 0x3b3c, 5 },		/* 59.2 C */
+	{ 0x3b94, 4 },		/* 59.6 C */
+	{ 0x3be3, 3 },		/* 58.9 C */
+	{ 0x3c29, 2 },		/* 59.2 C */
+	{ 0xffff, 1 }		/* on fire */
+};
+static struct {
+	int			temp;
+	int			fan_setting;
+} fan_down_table[] = {
+	{ 0x3700, 11 },		/* 55.0 C */
+	{ 0x374a, 6 },
+	{ 0x3800, 7 },		/* 56.0 C */
+	{ 0x3900, 8 },		/* 57.0 C */
+	{ 0x3a4a, 7 },		/* 58.3 C */
+	{ 0x3ad3, 6 },		/* 58.8 C */
+	{ 0x3b3c, 5 },		/* 59.2 C */
+	{ 0x3b94, 4 },		/* 58.9 C */
+	{ 0x3be3, 3 },		/* 58.9 C */
+	{ 0x3c29, 2 },		/* 59.2 C */
+	{ 0xffff, 1 }
+};
+
+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
+print_temp( const char *s, int temp )
+{
+	printk("%s%d.%d C", s ? s : "", temp>>8, (temp & 255)*10/256 );
+}
+
+static void
+tune_fan( int fan_setting )
+{
+	int val = (fan_setting << 3) | 7;
+	x.fan_level = fan_setting;
+	
+	//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("  Tuning fan: %d (%02x)\n", fan_setting, val );
+}
+
+static void
+poll_temp( void *param )
+{
+	int temp = read_reg( x.thermostat, 0, 2 );
+	int i, level, casetemp;
+
+	/* this actually occurs when the computer is loaded */
+	if( temp < 0 )
+		goto out;
+
+	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", x.fan_level );
+	}
+	x.temp = temp;
+	x.casetemp = casetemp;
+
+	level = -1;
+	for( i=0; (temp & 0xffff) > fan_down_table[i].temp ; i++ )
+		;
+	if( i < x.downind )
+		level = fan_down_table[i].fan_setting;
+	x.downind = i;
+
+	for( i=0; (temp & 0xfffe) >= fan_up_table[i+1].temp ; i++ )
+		;
+	if( x.upind < i )
+		level = fan_up_table[i].fan_setting;
+	x.upind = i;
+
+	if( level >= 0 )
+		tune_fan( level );
+ out:
+	x.timer.expires = jiffies + 8*HZ;
+	add_timer( &x.timer );
+}
+
+static void
+schedule_poll( unsigned long t )
+{
+	schedule_work(&poll_work);
+}
+
+/************************************************************************/
+/*	i2c probing and setup						*/
+/************************************************************************/
+
+static int
+do_attach( struct i2c_adapter *adapter )
+{
+	return i2c_probe( adapter, &addr_data, &do_detect );
+}
+
+static int
+do_detach( struct i2c_client *client )
+{
+	int err;
+
+	printk("do_detach: id %d\n", client->id );
+	if( (err=i2c_detach_client(client)) ) {
+		printk("failed to detach thermostat client\n");
+		return err;
+	}
+	kfree( client );
+	return 0;
+}
+
+static struct i2c_driver g4fan_driver = {  
+	.name		= "Apple G4 Thermostat/Fan",
+	.id		= I2C_DRIVERID_G4FAN,
+	.flags		= I2C_DF_NOTIFY,
+	.attach_adapter = &do_attach,
+	.detach_client	= &do_detach,
+	.command	= NULL,
+};
+
+static int
+detect_fan( struct i2c_client *cl )
+{
+	/* 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 detected at %02x\n", cl->addr );
+
+	if( x.fan ) {
+		x.error |= 2;
+		goto out;
+	}
+	x.fan = cl;
+	cl->id = FAN_CLIENT_ID;
+	strncpy( cl->name, "ADM1030 fan controller", sizeof(cl->name) );
+
+	if( i2c_attach_client( cl ) )
+		goto out;
+	return 0;
+ out:
+	if( cl != x.fan )
+		kfree( cl );
+	return 0;
+}
+
+static int
+detect_thermostat( struct i2c_client *cl ) 
+{
+	int hyst_temp, os_temp, temp;
+
+	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 detected at %02x\n", cl->addr );
+	print_temp("Temp: ", temp );
+	print_temp("  Hyst: ", hyst_temp );
+	print_temp("  OS: ", os_temp );
+	printk("\n");
+
+	if( x.thermostat ) {
+		x.error |= 1;
+		goto out;
+	}
+	x.temp = temp;
+	x.thermostat = cl;
+	x.overheat_temp = os_temp;
+	x.overheat_hyst = hyst_temp;
+	
+	cl->id = THERMOSTAT_CLIENT_ID;
+	strncpy( cl->name, "DS1775 thermostat", sizeof(cl->name) );
+
+	if( i2c_attach_client( cl ) )
+		goto out;
+	return 0;
+out:
+	kfree( cl );
+	return 0;
+}
+
+static int
+do_detect( struct i2c_adapter *adapter, int addr, int kind )
+{
+	struct i2c_client *cl;
+
+	if( strncmp(adapter->name, "uni-n", 5) )
+		return 0;
+	if( !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA
+				     | I2C_FUNC_SMBUS_WRITE_BYTE) )
+		return 0;
+
+	if( !(cl=kmalloc( sizeof(struct i2c_client), 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 detect_fan( cl );
+	return detect_thermostat( cl );
+}
+
+#define PRINT_REG( r )	printk("reg %02x = %02x\n", r, read_reg(x.fan, r, 1) )
+
+static int __init
+g4fan_init( void )
+{
+	struct apple_thermal_info *info;
+	struct device_node *np;
+	int ret, val;
+	
+	np = of_find_node_by_name(NULL, "power-mgt");
+	if (np == NULL)
+		return -ENODEV;
+	info = (struct apple_thermal_info*)get_property(np, "thermal-info", NULL);
+	of_node_put(np);
+	if (info == NULL)
+		return -ENODEV;
+	
+	/* check for G4 "Windtunnel" SMP */
+	if( machine_is_compatible("PowerMac3,6") ) {
+		if( info->id != 3 ) {
+			printk(KERN_ERR "g4fan: design id %d unknown\n", info->id);
+			return -ENODEV;
+		}
+	} else {
+		printk(KERN_ERR "g4fan: unsupported machine type\n");
+		return -ENODEV;
+	}
+	if( (ret=i2c_add_driver(&g4fan_driver)) )
+		return ret;
+
+	if( !x.thermostat || !x.fan ) {
+		i2c_del_driver(&g4fan_driver );
+		return -ENODEV;
+	}
+
+	/* 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.upind = x.downind = 1;
+	tune_fan( fan_up_table[x.upind].fan_setting );
+
+	INIT_WORK(&poll_work, poll_temp, NULL);
+
+	init_timer( &x.timer );
+	x.timer.expires = jiffies + 8*HZ;
+	x.timer.function = schedule_poll;
+	add_timer( &x.timer );
+	return 0;
+}
+
+static void __exit
+g4fan_exit( void )
+{
+	del_timer( &x.timer );
+
+	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 );
+
+	i2c_del_driver( &g4fan_driver );
+}
+
+module_init(g4fan_init);
+module_exit(g4fan_exit);
+