drivers/hwmon/coretemp.c - third_party/linux - Git at Google

 /*
  * coretemp.c - Linux kernel module for hardware monitoring
  *
  * Copyright (C) 2007 Rudolf Marek <r.marek@assembler.cz>
  *
  * Inspired from many hwmon drivers
  *
  * 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; version 2 of the License.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  * 02110-1301 USA.
  */

 #include <linux/module.h>
 #include <linux/delay.h>
 #include <linux/init.h>
 #include <linux/slab.h>
 #include <linux/jiffies.h>
 #include <linux/hwmon.h>
 #include <linux/sysfs.h>
 #include <linux/hwmon-sysfs.h>
 #include <linux/err.h>
 #include <linux/mutex.h>
 #include <linux/list.h>
 #include <linux/platform_device.h>
 #include <linux/cpu.h>
 #include <asm/msr.h>
 #include <asm/processor.h>

 #define DRVNAME	"coretemp"

 typedef enum { SHOW_TEMP, SHOW_TJMAX, SHOW_TTARGET, SHOW_LABEL,
 		SHOW_NAME } SHOW;

 /*
  * Functions declaration
  */

 static struct coretemp_data *coretemp_update_device(struct device *dev);

 struct coretemp_data {
 	struct device *hwmon_dev;
 	struct mutex update_lock;
 	const char *name;
 	u32 id;
 	char valid;		/* zero until following fields are valid */
 	unsigned long last_updated;	/* in jiffies */
 	int temp;
 	int tjmax;
 	int ttarget;
 	u8 alarm;
 };

 /*
  * Sysfs stuff
  */

 static ssize_t show_name(struct device *dev, struct device_attribute
 			  *devattr, char *buf)
 {
 	int ret;
 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 	struct coretemp_data *data = dev_get_drvdata(dev);

 	if (attr->index == SHOW_NAME)
 		ret = sprintf(buf, "%s\n", data->name);
 	else	/* show label */
 		ret = sprintf(buf, "Core %d\n", data->id);
 	return ret;
 }

 static ssize_t show_alarm(struct device *dev, struct device_attribute
 			  *devattr, char *buf)
 {
 	struct coretemp_data *data = coretemp_update_device(dev);
 	/* read the Out-of-spec log, never clear */
 	return sprintf(buf, "%d\n", data->alarm);
 }

 static ssize_t show_temp(struct device *dev,
 			 struct device_attribute *devattr, char *buf)
 {
 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 	struct coretemp_data *data = coretemp_update_device(dev);
 	int err;

 	if (attr->index == SHOW_TEMP)
 		err = data->valid ? sprintf(buf, "%d\n", data->temp) : -EAGAIN;
 	else if (attr->index == SHOW_TJMAX)
 		err = sprintf(buf, "%d\n", data->tjmax);
 	else
 		err = sprintf(buf, "%d\n", data->ttarget);
 	return err;
 }

 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL,
 			  SHOW_TEMP);
 static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO, show_temp, NULL,
 			  SHOW_TJMAX);
 static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO, show_temp, NULL,
 			  SHOW_TTARGET);
 static DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL);
 static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, show_name, NULL, SHOW_LABEL);
 static SENSOR_DEVICE_ATTR(name, S_IRUGO, show_name, NULL, SHOW_NAME);

 static struct attribute *coretemp_attributes[] = {
 	&sensor_dev_attr_name.dev_attr.attr,
 	&sensor_dev_attr_temp1_label.dev_attr.attr,
 	&dev_attr_temp1_crit_alarm.attr,
 	&sensor_dev_attr_temp1_input.dev_attr.attr,
 	&sensor_dev_attr_temp1_crit.dev_attr.attr,
 	NULL
 };

 static const struct attribute_group coretemp_group = {
 	.attrs = coretemp_attributes,
 };

 static struct coretemp_data *coretemp_update_device(struct device *dev)
 {
 	struct coretemp_data *data = dev_get_drvdata(dev);

 	mutex_lock(&data->update_lock);

 	if (!data->valid || time_after(jiffies, data->last_updated + HZ)) {
 		u32 eax, edx;

 		data->valid = 0;
 		rdmsr_on_cpu(data->id, MSR_IA32_THERM_STATUS, &eax, &edx);
 		data->alarm = (eax >> 5) & 1;
 		/* update only if data has been valid */
 		if (eax & 0x80000000) {
 			data->temp = data->tjmax - (((eax >> 16)
 							& 0x7f) * 1000);
 			data->valid = 1;
 		} else {
 			dev_dbg(dev, "Temperature data invalid (0x%x)\n", eax);
 		}
 		data->last_updated = jiffies;
 	}

 	mutex_unlock(&data->update_lock);
 	return data;
 }

 static int __devinit adjust_tjmax(struct cpuinfo_x86 *c, u32 id, struct device *dev)
 {
 	/* The 100C is default for both mobile and non mobile CPUs */

 	int tjmax = 100000;
 	int ismobile = 1;
 	int err;
 	u32 eax, edx;

 	/* Early chips have no MSR for TjMax */

 	if ((c->x86_model == 0xf) && (c->x86_mask < 4)) {
 		ismobile = 0;
 	}

 	if ((c->x86_model > 0xe) && (ismobile)) {

 		/* Now we can detect the mobile CPU using Intel provided table
 		   http://softwarecommunity.intel.com/Wiki/Mobility/720.htm
 		   For Core2 cores, check MSR 0x17, bit 28 1 = Mobile CPU
 		*/

 		err = rdmsr_safe_on_cpu(id, 0x17, &eax, &edx);
 		if (err) {
 			dev_warn(dev,
 				 "Unable to access MSR 0x17, assuming desktop"
 				 " CPU\n");
 			ismobile = 0;
 		} else if (!(eax & 0x10000000)) {
 			ismobile = 0;
 		}
 	}

 	if (ismobile) {

 		err = rdmsr_safe_on_cpu(id, 0xee, &eax, &edx);
 		if (err) {
 			dev_warn(dev,
 				 "Unable to access MSR 0xEE, for Tjmax, left"
 				 " at default");
 		} else if (eax & 0x40000000) {
 			tjmax = 85000;
 		}
 	} else {
 		dev_warn(dev, "Using relative temperature scale!\n");
 	}

 	return tjmax;
 }

 static int __devinit coretemp_probe(struct platform_device *pdev)
 {
 	struct coretemp_data *data;
 	struct cpuinfo_x86 *c = &cpu_data(pdev->id);
 	int err;
 	u32 eax, edx;

 	if (!(data = kzalloc(sizeof(struct coretemp_data), GFP_KERNEL))) {
 		err = -ENOMEM;
 		dev_err(&pdev->dev, "Out of memory\n");
 		goto exit;
 	}

 	data->id = pdev->id;
 	data->name = "coretemp";
 	mutex_init(&data->update_lock);

 	/* test if we can access the THERM_STATUS MSR */
 	err = rdmsr_safe_on_cpu(data->id, MSR_IA32_THERM_STATUS, &eax, &edx);
 	if (err) {
 		dev_err(&pdev->dev,
 			"Unable to access THERM_STATUS MSR, giving up\n");
 		goto exit_free;
 	}

 	/* Check if we have problem with errata AE18 of Core processors:
 	   Readings might stop update when processor visited too deep sleep,
 	   fixed for stepping D0 (6EC).
 	*/

 	if ((c->x86_model == 0xe) && (c->x86_mask < 0xc)) {
 		/* check for microcode update */
 		rdmsr_on_cpu(data->id, MSR_IA32_UCODE_REV, &eax, &edx);
 		if (edx < 0x39) {
 			err = -ENODEV;
 			dev_err(&pdev->dev,
 				"Errata AE18 not fixed, update BIOS or "
 				"microcode of the CPU!\n");
 			goto exit_free;
 		}
 	}

 	data->tjmax = adjust_tjmax(c, data->id, &pdev->dev);
 	platform_set_drvdata(pdev, data);

 	/* read the still undocumented IA32_TEMPERATURE_TARGET it exists
 	   on older CPUs but not in this register */

 	if (c->x86_model > 0xe) {
 		err = rdmsr_safe_on_cpu(data->id, 0x1a2, &eax, &edx);
 		if (err) {
 			dev_warn(&pdev->dev, "Unable to read"
 					" IA32_TEMPERATURE_TARGET MSR\n");
 		} else {
 			data->ttarget = data->tjmax -
 					(((eax >> 8) & 0xff) * 1000);
 			err = device_create_file(&pdev->dev,
 					&sensor_dev_attr_temp1_max.dev_attr);
 			if (err)
 				goto exit_free;
 		}
 	}

 	if ((err = sysfs_create_group(&pdev->dev.kobj, &coretemp_group)))
 		goto exit_dev;

 	data->hwmon_dev = hwmon_device_register(&pdev->dev);
 	if (IS_ERR(data->hwmon_dev)) {
 		err = PTR_ERR(data->hwmon_dev);
 		dev_err(&pdev->dev, "Class registration failed (%d)\n",
 			err);
 		goto exit_class;
 	}

 	return 0;

 exit_class:
 	sysfs_remove_group(&pdev->dev.kobj, &coretemp_group);
 exit_dev:
 	device_remove_file(&pdev->dev, &sensor_dev_attr_temp1_max.dev_attr);
 exit_free:
 	kfree(data);
 exit:
 	return err;
 }

 static int __devexit coretemp_remove(struct platform_device *pdev)
 {
 	struct coretemp_data *data = platform_get_drvdata(pdev);

 	hwmon_device_unregister(data->hwmon_dev);
 	sysfs_remove_group(&pdev->dev.kobj, &coretemp_group);
 	device_remove_file(&pdev->dev, &sensor_dev_attr_temp1_max.dev_attr);
 	platform_set_drvdata(pdev, NULL);
 	kfree(data);
 	return 0;
 }

 static struct platform_driver coretemp_driver = {
 	.driver = {
 		.owner = THIS_MODULE,
 		.name = DRVNAME,
 	},
 	.probe = coretemp_probe,
 	.remove = __devexit_p(coretemp_remove),
 };

 struct pdev_entry {
 	struct list_head list;
 	struct platform_device *pdev;
 	unsigned int cpu;
 };

 static LIST_HEAD(pdev_list);
 static DEFINE_MUTEX(pdev_list_mutex);

 static int __cpuinit coretemp_device_add(unsigned int cpu)
 {
 	int err;
 	struct platform_device *pdev;
 	struct pdev_entry *pdev_entry;

 	pdev = platform_device_alloc(DRVNAME, cpu);
 	if (!pdev) {
 		err = -ENOMEM;
 		printk(KERN_ERR DRVNAME ": Device allocation failed\n");
 		goto exit;
 	}

 	pdev_entry = kzalloc(sizeof(struct pdev_entry), GFP_KERNEL);
 	if (!pdev_entry) {
 		err = -ENOMEM;
 		goto exit_device_put;
 	}

 	err = platform_device_add(pdev);
 	if (err) {
 		printk(KERN_ERR DRVNAME ": Device addition failed (%d)\n",
 		       err);
 		goto exit_device_free;
 	}

 	pdev_entry->pdev = pdev;
 	pdev_entry->cpu = cpu;
 	mutex_lock(&pdev_list_mutex);
 	list_add_tail(&pdev_entry->list, &pdev_list);
 	mutex_unlock(&pdev_list_mutex);

 	return 0;

 exit_device_free:
 	kfree(pdev_entry);
 exit_device_put:
 	platform_device_put(pdev);
 exit:
 	return err;
 }

 #ifdef CONFIG_HOTPLUG_CPU
 static void coretemp_device_remove(unsigned int cpu)
 {
 	struct pdev_entry *p, *n;
 	mutex_lock(&pdev_list_mutex);
 	list_for_each_entry_safe(p, n, &pdev_list, list) {
 		if (p->cpu == cpu) {
 			platform_device_unregister(p->pdev);
 			list_del(&p->list);
 			kfree(p);
 		}
 	}
 	mutex_unlock(&pdev_list_mutex);
 }

 static int __cpuinit coretemp_cpu_callback(struct notifier_block *nfb,
 				 unsigned long action, void *hcpu)
 {
 	unsigned int cpu = (unsigned long) hcpu;

 	switch (action) {
 	case CPU_ONLINE:
 	case CPU_DOWN_FAILED:
 		coretemp_device_add(cpu);
 		break;
 	case CPU_DOWN_PREPARE:
 		coretemp_device_remove(cpu);
 		break;
 	}
 	return NOTIFY_OK;
 }

 static struct notifier_block coretemp_cpu_notifier __refdata = {
 	.notifier_call = coretemp_cpu_callback,
 };
 #endif				/* !CONFIG_HOTPLUG_CPU */

 static int __init coretemp_init(void)
 {
 	int i, err = -ENODEV;
 	struct pdev_entry *p, *n;

 	/* quick check if we run Intel */
 	if (cpu_data(0).x86_vendor != X86_VENDOR_INTEL)
 		goto exit;

 	err = platform_driver_register(&coretemp_driver);
 	if (err)
 		goto exit;

 	for_each_online_cpu(i) {
 		struct cpuinfo_x86 *c = &cpu_data(i);

 		/* check if family 6, models 0xe, 0xf, 0x16, 0x17, 0x1A */
 		if ((c->cpuid_level < 0) || (c->x86 != 0x6) ||
 		    !((c->x86_model == 0xe) || (c->x86_model == 0xf) ||
 			(c->x86_model == 0x16) || (c->x86_model == 0x17) ||
 			(c->x86_model == 0x1A))) {

 			/* supported CPU not found, but report the unknown
 			   family 6 CPU */
 			if ((c->x86 == 0x6) && (c->x86_model > 0xf))
 				printk(KERN_WARNING DRVNAME ": Unknown CPU "
 					"model %x\n", c->x86_model);
 			continue;
 		}

 		err = coretemp_device_add(i);
 		if (err)
 			goto exit_devices_unreg;
 	}
 	if (list_empty(&pdev_list)) {
 		err = -ENODEV;
 		goto exit_driver_unreg;
 	}

 #ifdef CONFIG_HOTPLUG_CPU
 	register_hotcpu_notifier(&coretemp_cpu_notifier);
 #endif
 	return 0;

 exit_devices_unreg:
 	mutex_lock(&pdev_list_mutex);
 	list_for_each_entry_safe(p, n, &pdev_list, list) {
 		platform_device_unregister(p->pdev);
 		list_del(&p->list);
 		kfree(p);
 	}
 	mutex_unlock(&pdev_list_mutex);
 exit_driver_unreg:
 	platform_driver_unregister(&coretemp_driver);
 exit:
 	return err;
 }

 static void __exit coretemp_exit(void)
 {
 	struct pdev_entry *p, *n;
 #ifdef CONFIG_HOTPLUG_CPU
 	unregister_hotcpu_notifier(&coretemp_cpu_notifier);
 #endif
 	mutex_lock(&pdev_list_mutex);
 	list_for_each_entry_safe(p, n, &pdev_list, list) {
 		platform_device_unregister(p->pdev);
 		list_del(&p->list);
 		kfree(p);
 	}
 	mutex_unlock(&pdev_list_mutex);
 	platform_driver_unregister(&coretemp_driver);
 }

 MODULE_AUTHOR("Rudolf Marek <r.marek@assembler.cz>");
 MODULE_DESCRIPTION("Intel Core temperature monitor");
 MODULE_LICENSE("GPL");

 module_init(coretemp_init)
 module_exit(coretemp_exit)
	/*
	* coretemp.c - Linux kernel module for hardware monitoring
	*
	* Copyright (C) 2007 Rudolf Marek <r.marek@assembler.cz>
	*
	* Inspired from many hwmon drivers
	*
	* 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; version 2 of the License.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
	* 02110-1301 USA.
	*/

	#include <linux/module.h>
	#include <linux/delay.h>
	#include <linux/init.h>
	#include <linux/slab.h>
	#include <linux/jiffies.h>
	#include <linux/hwmon.h>
	#include <linux/sysfs.h>
	#include <linux/hwmon-sysfs.h>
	#include <linux/err.h>
	#include <linux/mutex.h>
	#include <linux/list.h>
	#include <linux/platform_device.h>
	#include <linux/cpu.h>
	#include <asm/msr.h>
	#include <asm/processor.h>

	#define DRVNAME "coretemp"

	typedef enum { SHOW_TEMP, SHOW_TJMAX, SHOW_TTARGET, SHOW_LABEL,
	SHOW_NAME } SHOW;

	/*
	* Functions declaration
	*/

	static struct coretemp_data coretemp_update_device(struct device dev);

	struct coretemp_data {
	struct device *hwmon_dev;
	struct mutex update_lock;
	const char *name;
	u32 id;
	char valid; /* zero until following fields are valid */
	unsigned long last_updated; /* in jiffies */
	int temp;
	int tjmax;
	int ttarget;
	u8 alarm;
	};

	/*
	* Sysfs stuff
	*/

	static ssize_t show_name(struct device *dev, struct device_attribute
	devattr, char buf)
	{
	int ret;
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct coretemp_data *data = dev_get_drvdata(dev);

	if (attr->index == SHOW_NAME)
	ret = sprintf(buf, "%s\n", data->name);
	else /* show label */
	ret = sprintf(buf, "Core %d\n", data->id);
	return ret;
	}

	static ssize_t show_alarm(struct device *dev, struct device_attribute
	devattr, char buf)
	{
	struct coretemp_data *data = coretemp_update_device(dev);
	/* read the Out-of-spec log, never clear */
	return sprintf(buf, "%d\n", data->alarm);
	}

	static ssize_t show_temp(struct device *dev,
	struct device_attribute devattr, char buf)
	{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct coretemp_data *data = coretemp_update_device(dev);
	int err;

	if (attr->index == SHOW_TEMP)
	err = data->valid ? sprintf(buf, "%d\n", data->temp) : -EAGAIN;
	else if (attr->index == SHOW_TJMAX)
	err = sprintf(buf, "%d\n", data->tjmax);
	else
	err = sprintf(buf, "%d\n", data->ttarget);
	return err;
	}

	static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL,
	SHOW_TEMP);
	static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO, show_temp, NULL,
	SHOW_TJMAX);
	static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO, show_temp, NULL,
	SHOW_TTARGET);
	static DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL);
	static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, show_name, NULL, SHOW_LABEL);
	static SENSOR_DEVICE_ATTR(name, S_IRUGO, show_name, NULL, SHOW_NAME);

	static struct attribute *coretemp_attributes[] = {
	&sensor_dev_attr_name.dev_attr.attr,
	&sensor_dev_attr_temp1_label.dev_attr.attr,
	&dev_attr_temp1_crit_alarm.attr,
	&sensor_dev_attr_temp1_input.dev_attr.attr,
	&sensor_dev_attr_temp1_crit.dev_attr.attr,
	NULL
	};

	static const struct attribute_group coretemp_group = {
	.attrs = coretemp_attributes,
	};

	static struct coretemp_data coretemp_update_device(struct device dev)
	{
	struct coretemp_data *data = dev_get_drvdata(dev);

	mutex_lock(&data->update_lock);

	if (!data->valid \|\| time_after(jiffies, data->last_updated + HZ)) {
	u32 eax, edx;

	data->valid = 0;
	rdmsr_on_cpu(data->id, MSR_IA32_THERM_STATUS, &eax, &edx);
	data->alarm = (eax >> 5) & 1;
	/* update only if data has been valid */
	if (eax & 0x80000000) {
	data->temp = data->tjmax - (((eax >> 16)
	& 0x7f) * 1000);
	data->valid = 1;
	} else {
	dev_dbg(dev, "Temperature data invalid (0x%x)\n", eax);
	}
	data->last_updated = jiffies;
	}

	mutex_unlock(&data->update_lock);
	return data;
	}

	static int __devinit adjust_tjmax(struct cpuinfo_x86 c, u32 id, struct device dev)
	{
	/* The 100C is default for both mobile and non mobile CPUs */

	int tjmax = 100000;
	int ismobile = 1;
	int err;
	u32 eax, edx;

	/* Early chips have no MSR for TjMax */

	if ((c->x86_model == 0xf) && (c->x86_mask < 4)) {
	ismobile = 0;
	}

	if ((c->x86_model > 0xe) && (ismobile)) {

	/* Now we can detect the mobile CPU using Intel provided table
	http://softwarecommunity.intel.com/Wiki/Mobility/720.htm
	For Core2 cores, check MSR 0x17, bit 28 1 = Mobile CPU
	*/

	err = rdmsr_safe_on_cpu(id, 0x17, &eax, &edx);
	if (err) {
	dev_warn(dev,
	"Unable to access MSR 0x17, assuming desktop"
	" CPU\n");
	ismobile = 0;
	} else if (!(eax & 0x10000000)) {
	ismobile = 0;
	}
	}

	if (ismobile) {

	err = rdmsr_safe_on_cpu(id, 0xee, &eax, &edx);
	if (err) {
	dev_warn(dev,
	"Unable to access MSR 0xEE, for Tjmax, left"
	" at default");
	} else if (eax & 0x40000000) {
	tjmax = 85000;
	}
	} else {
	dev_warn(dev, "Using relative temperature scale!\n");
	}

	return tjmax;
	}

	static int __devinit coretemp_probe(struct platform_device *pdev)
	{
	struct coretemp_data *data;
	struct cpuinfo_x86 *c = &cpu_data(pdev->id);
	int err;
	u32 eax, edx;

	if (!(data = kzalloc(sizeof(struct coretemp_data), GFP_KERNEL))) {
	err = -ENOMEM;
	dev_err(&pdev->dev, "Out of memory\n");
	goto exit;
	}

	data->id = pdev->id;
	data->name = "coretemp";
	mutex_init(&data->update_lock);

	/* test if we can access the THERM_STATUS MSR */
	err = rdmsr_safe_on_cpu(data->id, MSR_IA32_THERM_STATUS, &eax, &edx);
	if (err) {
	dev_err(&pdev->dev,
	"Unable to access THERM_STATUS MSR, giving up\n");
	goto exit_free;
	}

	/* Check if we have problem with errata AE18 of Core processors:
	Readings might stop update when processor visited too deep sleep,
	fixed for stepping D0 (6EC).
	*/

	if ((c->x86_model == 0xe) && (c->x86_mask < 0xc)) {
	/* check for microcode update */
	rdmsr_on_cpu(data->id, MSR_IA32_UCODE_REV, &eax, &edx);
	if (edx < 0x39) {
	err = -ENODEV;
	dev_err(&pdev->dev,
	"Errata AE18 not fixed, update BIOS or "
	"microcode of the CPU!\n");
	goto exit_free;
	}
	}

	data->tjmax = adjust_tjmax(c, data->id, &pdev->dev);
	platform_set_drvdata(pdev, data);

	/* read the still undocumented IA32_TEMPERATURE_TARGET it exists
	on older CPUs but not in this register */

	if (c->x86_model > 0xe) {
	err = rdmsr_safe_on_cpu(data->id, 0x1a2, &eax, &edx);
	if (err) {
	dev_warn(&pdev->dev, "Unable to read"
	" IA32_TEMPERATURE_TARGET MSR\n");
	} else {
	data->ttarget = data->tjmax -
	(((eax >> 8) & 0xff) * 1000);
	err = device_create_file(&pdev->dev,
	&sensor_dev_attr_temp1_max.dev_attr);
	if (err)
	goto exit_free;
	}
	}

	if ((err = sysfs_create_group(&pdev->dev.kobj, &coretemp_group)))
	goto exit_dev;

	data->hwmon_dev = hwmon_device_register(&pdev->dev);
	if (IS_ERR(data->hwmon_dev)) {
	err = PTR_ERR(data->hwmon_dev);
	dev_err(&pdev->dev, "Class registration failed (%d)\n",
	err);
	goto exit_class;
	}

	return 0;

	exit_class:
	sysfs_remove_group(&pdev->dev.kobj, &coretemp_group);
	exit_dev:
	device_remove_file(&pdev->dev, &sensor_dev_attr_temp1_max.dev_attr);
	exit_free:
	kfree(data);
	exit:
	return err;
	}

	static int __devexit coretemp_remove(struct platform_device *pdev)
	{
	struct coretemp_data *data = platform_get_drvdata(pdev);

	hwmon_device_unregister(data->hwmon_dev);
	sysfs_remove_group(&pdev->dev.kobj, &coretemp_group);
	device_remove_file(&pdev->dev, &sensor_dev_attr_temp1_max.dev_attr);
	platform_set_drvdata(pdev, NULL);
	kfree(data);
	return 0;
	}

	static struct platform_driver coretemp_driver = {
	.driver = {
	.owner = THIS_MODULE,
	.name = DRVNAME,
	},
	.probe = coretemp_probe,
	.remove = __devexit_p(coretemp_remove),
	};

	struct pdev_entry {
	struct list_head list;
	struct platform_device *pdev;
	unsigned int cpu;
	};

	static LIST_HEAD(pdev_list);
	static DEFINE_MUTEX(pdev_list_mutex);

	static int __cpuinit coretemp_device_add(unsigned int cpu)
	{
	int err;
	struct platform_device *pdev;
	struct pdev_entry *pdev_entry;

	pdev = platform_device_alloc(DRVNAME, cpu);
	if (!pdev) {
	err = -ENOMEM;
	printk(KERN_ERR DRVNAME ": Device allocation failed\n");
	goto exit;
	}

	pdev_entry = kzalloc(sizeof(struct pdev_entry), GFP_KERNEL);
	if (!pdev_entry) {
	err = -ENOMEM;
	goto exit_device_put;
	}

	err = platform_device_add(pdev);
	if (err) {
	printk(KERN_ERR DRVNAME ": Device addition failed (%d)\n",
	err);
	goto exit_device_free;
	}

	pdev_entry->pdev = pdev;
	pdev_entry->cpu = cpu;
	mutex_lock(&pdev_list_mutex);
	list_add_tail(&pdev_entry->list, &pdev_list);
	mutex_unlock(&pdev_list_mutex);

	return 0;

	exit_device_free:
	kfree(pdev_entry);
	exit_device_put:
	platform_device_put(pdev);
	exit:
	return err;
	}

	#ifdef CONFIG_HOTPLUG_CPU
	static void coretemp_device_remove(unsigned int cpu)
	{
	struct pdev_entry p, n;
	mutex_lock(&pdev_list_mutex);
	list_for_each_entry_safe(p, n, &pdev_list, list) {
	if (p->cpu == cpu) {
	platform_device_unregister(p->pdev);
	list_del(&p->list);
	kfree(p);
	}
	}
	mutex_unlock(&pdev_list_mutex);
	}

	static int __cpuinit coretemp_cpu_callback(struct notifier_block *nfb,
	unsigned long action, void *hcpu)
	{
	unsigned int cpu = (unsigned long) hcpu;

	switch (action) {
	case CPU_ONLINE:
	case CPU_DOWN_FAILED:
	coretemp_device_add(cpu);
	break;
	case CPU_DOWN_PREPARE:
	coretemp_device_remove(cpu);
	break;
	}
	return NOTIFY_OK;
	}

	static struct notifier_block coretemp_cpu_notifier __refdata = {
	.notifier_call = coretemp_cpu_callback,
	};
	#endif /* !CONFIG_HOTPLUG_CPU */

	static int __init coretemp_init(void)
	{
	int i, err = -ENODEV;
	struct pdev_entry p, n;

	/* quick check if we run Intel */
	if (cpu_data(0).x86_vendor != X86_VENDOR_INTEL)
	goto exit;

	err = platform_driver_register(&coretemp_driver);
	if (err)
	goto exit;

	for_each_online_cpu(i) {
	struct cpuinfo_x86 *c = &cpu_data(i);

	/* check if family 6, models 0xe, 0xf, 0x16, 0x17, 0x1A */
	if ((c->cpuid_level < 0) \|\| (c->x86 != 0x6) \|\|
	!((c->x86_model == 0xe) \|\| (c->x86_model == 0xf) \|\|
	(c->x86_model == 0x16) \|\| (c->x86_model == 0x17) \|\|
	(c->x86_model == 0x1A))) {

	/* supported CPU not found, but report the unknown
	family 6 CPU */
	if ((c->x86 == 0x6) && (c->x86_model > 0xf))
	printk(KERN_WARNING DRVNAME ": Unknown CPU "
	"model %x\n", c->x86_model);
	continue;
	}

	err = coretemp_device_add(i);
	if (err)
	goto exit_devices_unreg;
	}
	if (list_empty(&pdev_list)) {
	err = -ENODEV;
	goto exit_driver_unreg;
	}

	#ifdef CONFIG_HOTPLUG_CPU
	register_hotcpu_notifier(&coretemp_cpu_notifier);
	#endif
	return 0;

	exit_devices_unreg:
	mutex_lock(&pdev_list_mutex);
	list_for_each_entry_safe(p, n, &pdev_list, list) {
	platform_device_unregister(p->pdev);
	list_del(&p->list);
	kfree(p);
	}
	mutex_unlock(&pdev_list_mutex);
	exit_driver_unreg:
	platform_driver_unregister(&coretemp_driver);
	exit:
	return err;
	}

	static void __exit coretemp_exit(void)
	{
	struct pdev_entry p, n;
	#ifdef CONFIG_HOTPLUG_CPU
	unregister_hotcpu_notifier(&coretemp_cpu_notifier);
	#endif
	mutex_lock(&pdev_list_mutex);
	list_for_each_entry_safe(p, n, &pdev_list, list) {
	platform_device_unregister(p->pdev);
	list_del(&p->list);
	kfree(p);
	}
	mutex_unlock(&pdev_list_mutex);
	platform_driver_unregister(&coretemp_driver);
	}

	MODULE_AUTHOR("Rudolf Marek <r.marek@assembler.cz>");
	MODULE_DESCRIPTION("Intel Core temperature monitor");
	MODULE_LICENSE("GPL");

	module_init(coretemp_init)
	module_exit(coretemp_exit)