hwmon: New coretemp driver
Add the support for the digital temperature sensor found in recent
Intel Core CPUs.
Signed-off-by: Rudolf Marek <r.marek@assembler.cz>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
diff --git a/drivers/hwmon/coretemp.c b/drivers/hwmon/coretemp.c
new file mode 100644
index 0000000..03b1f65
--- /dev/null
+++ b/drivers/hwmon/coretemp.c
@@ -0,0 +1,406 @@
+/*
+ * 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:
+ coretemp_device_add(cpu);
+ break;
+ case CPU_DEAD:
+ 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)