/*
* 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_LABEL, SHOW_NAME } SHOW;
/*
* Functions declaration
*/
static struct coretemp_data *coretemp_update_device(struct device *dev);
struct coretemp_data {
struct class_device *class_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;
u8 alarm;
};
static struct coretemp_data *coretemp_update_device(struct device *dev);
/*
* 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
err = sprintf(buf, "%d\n", data->tjmax);
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 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 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);
/* Tjmax default is 100 degrees C */
data->tjmax = 100000;
/* 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;
}
/* Some processors have Tjmax 85 following magic should detect it
Intel won't disclose the information without signed NDA, but
individuals cannot sign it. Catch(ed) 22.
*/
if (((c->x86_model == 0xf) && (c->x86_mask > 3)) ||
(c->x86_model == 0xe)) {
err = rdmsr_safe_on_cpu(data->id, 0xee, &eax, &edx);
if (err) {
dev_warn(&pdev->dev,
"Unable to access MSR 0xEE, Tjmax left at %d "
"degrees C\n", data->tjmax/1000);
} else if (eax & 0x40000000) {
data->tjmax = 85000;
}
}
platform_set_drvdata(pdev, data);
if ((err = sysfs_create_group(&pdev->dev.kobj, &coretemp_group)))
goto exit_free;
data->class_dev = hwmon_device_register(&pdev->dev);
if (IS_ERR(data->class_dev)) {
err = PTR_ERR(data->class_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_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->class_dev);
sysfs_remove_group(&pdev->dev.kobj, &coretemp_group);
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
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 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_ONLINE_FROZEN:
coretemp_device_add(cpu);
break;
case CPU_DEAD:
case CPU_DEAD_FROZEN:
coretemp_device_remove(cpu);
break;
}
return NOTIFY_OK;
}
static struct notifier_block __cpuinitdata coretemp_cpu_notifier = {
.notifier_call = coretemp_cpu_callback,
};
#endif /* !CONFIG_HOTPLUG_CPU */
static int __init coretemp_init(void)
{
int i, err = -ENODEV;
struct pdev_entry *p, *n;
printk(KERN_NOTICE DRVNAME ": This driver uses undocumented features "
"of Core CPU. Temperature might be wrong!\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 e, f */
if ((c->cpuid_level < 0) || (c->x86 != 0x6) ||
!((c->x86_model == 0xe) || (c->x86_model == 0xf))) {
/* 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)
