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Commit 70c38772 authored by Harald Welte's avatar Harald Welte Committed by Jean Delvare
Browse files

hwmon: Add driver for VIA CPU core temperature



This is a driver for the on-die digital temperature sensor of
VIA's recent CPU models.

[JD: Misc clean-ups.]

Signed-off-by: default avatarHarald Welte <HaraldWelte@viatech.com>
Cc: Juerg Haefliger <juergh@gmail.com>
Signed-off-by: default avatarJean Delvare <khali@linux-fr.org>
Tested-by: default avatarAdam Nielsen <a.nielsen@shikadi.net>
parent fa0bff02
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+8 −0
Original line number Original line Diff line number Diff line
@@ -822,6 +822,14 @@ config SENSORS_TMP421
	  This driver can also be built as a module.  If so, the module
	  This driver can also be built as a module.  If so, the module
	  will be called tmp421.
	  will be called tmp421.


config SENSORS_VIA_CPUTEMP
	tristate "VIA CPU temperature sensor"
	depends on X86
	help
	  If you say yes here you get support for the temperature
	  sensor inside your CPU. Supported are all known variants of
	  the VIA C7 and Nano.

config SENSORS_VIA686A
config SENSORS_VIA686A
	tristate "VIA686A"
	tristate "VIA686A"
	depends on PCI
	depends on PCI
+1 −0
Original line number Original line Diff line number Diff line
@@ -88,6 +88,7 @@ obj-$(CONFIG_SENSORS_SMSC47M192)+= smsc47m192.o
obj-$(CONFIG_SENSORS_THMC50)	+= thmc50.o
obj-$(CONFIG_SENSORS_THMC50)	+= thmc50.o
obj-$(CONFIG_SENSORS_TMP401)	+= tmp401.o
obj-$(CONFIG_SENSORS_TMP401)	+= tmp401.o
obj-$(CONFIG_SENSORS_TMP421)	+= tmp421.o
obj-$(CONFIG_SENSORS_TMP421)	+= tmp421.o
obj-$(CONFIG_SENSORS_VIA_CPUTEMP)+= via-cputemp.o
obj-$(CONFIG_SENSORS_VIA686A)	+= via686a.o
obj-$(CONFIG_SENSORS_VIA686A)	+= via686a.o
obj-$(CONFIG_SENSORS_VT1211)	+= vt1211.o
obj-$(CONFIG_SENSORS_VT1211)	+= vt1211.o
obj-$(CONFIG_SENSORS_VT8231)	+= vt8231.o
obj-$(CONFIG_SENSORS_VT8231)	+= vt8231.o
+356 −0
Original line number Original line Diff line number Diff line
/*
 * via-cputemp.c - Driver for VIA CPU core temperature monitoring
 * Copyright (C) 2009 VIA Technologies, Inc.
 *
 * based on existing coretemp.c, which is
 *
 * Copyright (C) 2007 Rudolf Marek <r.marek@assembler.cz>
 *
 * 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	"via_cputemp"

enum { SHOW_TEMP, SHOW_LABEL, SHOW_NAME } SHOW;

/*
 * Functions declaration
 */

struct via_cputemp_data {
	struct device *hwmon_dev;
	const char *name;
	u32 id;
	u32 msr;
};

/*
 * 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 via_cputemp_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_temp(struct device *dev,
			 struct device_attribute *devattr, char *buf)
{
	struct via_cputemp_data *data = dev_get_drvdata(dev);
	u32 eax, edx;
	int err;

	err = rdmsr_safe_on_cpu(data->id, data->msr, &eax, &edx);
	if (err)
		return -EAGAIN;

	return sprintf(buf, "%lu\n", ((unsigned long)eax & 0xffffff) * 1000);
}

static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL,
			  SHOW_TEMP);
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 *via_cputemp_attributes[] = {
	&sensor_dev_attr_name.dev_attr.attr,
	&sensor_dev_attr_temp1_label.dev_attr.attr,
	&sensor_dev_attr_temp1_input.dev_attr.attr,
	NULL
};

static const struct attribute_group via_cputemp_group = {
	.attrs = via_cputemp_attributes,
};

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

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

	data->id = pdev->id;
	data->name = "via_cputemp";

	switch (c->x86_model) {
	case 0xA:
		/* C7 A */
	case 0xD:
		/* C7 D */
		data->msr = 0x1169;
		break;
	case 0xF:
		/* Nano */
		data->msr = 0x1423;
		break;
	default:
		err = -ENODEV;
		goto exit_free;
	}

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

	platform_set_drvdata(pdev, data);

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

	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_remove;
	}

	return 0;

exit_remove:
	sysfs_remove_group(&pdev->dev.kobj, &via_cputemp_group);
exit_free:
	platform_set_drvdata(pdev, NULL);
	kfree(data);
exit:
	return err;
}

static int __devexit via_cputemp_remove(struct platform_device *pdev)
{
	struct via_cputemp_data *data = platform_get_drvdata(pdev);

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

static struct platform_driver via_cputemp_driver = {
	.driver = {
		.owner = THIS_MODULE,
		.name = DRVNAME,
	},
	.probe = via_cputemp_probe,
	.remove = __devexit_p(via_cputemp_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 via_cputemp_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 via_cputemp_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 via_cputemp_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:
		via_cputemp_device_add(cpu);
		break;
	case CPU_DOWN_PREPARE:
		via_cputemp_device_remove(cpu);
		break;
	}
	return NOTIFY_OK;
}

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

static int __init via_cputemp_init(void)
{
	int i, err;
	struct pdev_entry *p, *n;

	if (cpu_data(0).x86_vendor != X86_VENDOR_CENTAUR) {
		printk(KERN_DEBUG DRVNAME ": Not a VIA CPU\n");
		err = -ENODEV;
		goto exit;
	}

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

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

		if (c->x86 != 6)
			continue;

		if (c->x86_model < 0x0a)
			continue;

		if (c->x86_model > 0x0f) {
			printk(KERN_WARNING DRVNAME ": Unknown CPU "
				"model 0x%x\n", c->x86_model);
			continue;
		}

		err = via_cputemp_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(&via_cputemp_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(&via_cputemp_driver);
exit:
	return err;
}

static void __exit via_cputemp_exit(void)
{
	struct pdev_entry *p, *n;
#ifdef CONFIG_HOTPLUG_CPU
	unregister_hotcpu_notifier(&via_cputemp_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(&via_cputemp_driver);
}

MODULE_AUTHOR("Harald Welte <HaraldWelte@viatech.com>");
MODULE_DESCRIPTION("VIA CPU temperature monitor");
MODULE_LICENSE("GPL");

module_init(via_cputemp_init)
module_exit(via_cputemp_exit)