2 * coretemp.c - Linux kernel module for hardware monitoring
4 * Copyright (C) 2007 Rudolf Marek <r.marek@assembler.cz>
6 * Inspired from many hwmon drivers
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; version 2 of the License.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
23 #include <linux/module.h>
24 #include <linux/delay.h>
25 #include <linux/init.h>
26 #include <linux/slab.h>
27 #include <linux/jiffies.h>
28 #include <linux/hwmon.h>
29 #include <linux/sysfs.h>
30 #include <linux/hwmon-sysfs.h>
31 #include <linux/err.h>
32 #include <linux/mutex.h>
33 #include <linux/list.h>
34 #include <linux/platform_device.h>
35 #include <linux/cpu.h>
37 #include <asm/processor.h>
39 #define DRVNAME "coretemp"
41 typedef enum { SHOW_TEMP, SHOW_TJMAX, SHOW_TTARGET, SHOW_LABEL,
45 * Functions declaration
48 static struct coretemp_data *coretemp_update_device(struct device *dev);
50 struct coretemp_data {
51 struct device *hwmon_dev;
52 struct mutex update_lock;
56 char valid; /* zero until following fields are valid */
57 unsigned long last_updated; /* in jiffies */
68 static ssize_t show_name(struct device *dev, struct device_attribute
72 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
73 struct coretemp_data *data = dev_get_drvdata(dev);
75 if (attr->index == SHOW_NAME)
76 ret = sprintf(buf, "%s\n", data->name);
78 ret = sprintf(buf, "Core %d\n", data->core_id);
82 static ssize_t show_alarm(struct device *dev, struct device_attribute
85 struct coretemp_data *data = coretemp_update_device(dev);
86 /* read the Out-of-spec log, never clear */
87 return sprintf(buf, "%d\n", data->alarm);
90 static ssize_t show_temp(struct device *dev,
91 struct device_attribute *devattr, char *buf)
93 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
94 struct coretemp_data *data = coretemp_update_device(dev);
97 if (attr->index == SHOW_TEMP)
98 err = data->valid ? sprintf(buf, "%d\n", data->temp) : -EAGAIN;
99 else if (attr->index == SHOW_TJMAX)
100 err = sprintf(buf, "%d\n", data->tjmax);
102 err = sprintf(buf, "%d\n", data->ttarget);
106 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL,
108 static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO, show_temp, NULL,
110 static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO, show_temp, NULL,
112 static DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL);
113 static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, show_name, NULL, SHOW_LABEL);
114 static SENSOR_DEVICE_ATTR(name, S_IRUGO, show_name, NULL, SHOW_NAME);
116 static struct attribute *coretemp_attributes[] = {
117 &sensor_dev_attr_name.dev_attr.attr,
118 &sensor_dev_attr_temp1_label.dev_attr.attr,
119 &dev_attr_temp1_crit_alarm.attr,
120 &sensor_dev_attr_temp1_input.dev_attr.attr,
121 &sensor_dev_attr_temp1_crit.dev_attr.attr,
125 static const struct attribute_group coretemp_group = {
126 .attrs = coretemp_attributes,
129 static struct coretemp_data *coretemp_update_device(struct device *dev)
131 struct coretemp_data *data = dev_get_drvdata(dev);
133 mutex_lock(&data->update_lock);
135 if (!data->valid || time_after(jiffies, data->last_updated + HZ)) {
139 rdmsr_on_cpu(data->id, MSR_IA32_THERM_STATUS, &eax, &edx);
140 data->alarm = (eax >> 5) & 1;
141 /* update only if data has been valid */
142 if (eax & 0x80000000) {
143 data->temp = data->tjmax - (((eax >> 16)
147 dev_dbg(dev, "Temperature data invalid (0x%x)\n", eax);
149 data->last_updated = jiffies;
152 mutex_unlock(&data->update_lock);
156 static int __devinit adjust_tjmax(struct cpuinfo_x86 *c, u32 id, struct device *dev)
158 /* The 100C is default for both mobile and non mobile CPUs */
165 /* Early chips have no MSR for TjMax */
167 if ((c->x86_model == 0xf) && (c->x86_mask < 4)) {
171 if ((c->x86_model > 0xe) && (ismobile)) {
173 /* Now we can detect the mobile CPU using Intel provided table
174 http://softwarecommunity.intel.com/Wiki/Mobility/720.htm
175 For Core2 cores, check MSR 0x17, bit 28 1 = Mobile CPU
178 err = rdmsr_safe_on_cpu(id, 0x17, &eax, &edx);
181 "Unable to access MSR 0x17, assuming desktop"
184 } else if (!(eax & 0x10000000)) {
191 err = rdmsr_safe_on_cpu(id, 0xee, &eax, &edx);
194 "Unable to access MSR 0xEE, for Tjmax, left"
196 } else if (eax & 0x40000000) {
200 dev_warn(dev, "Using relative temperature scale!\n");
206 static int __devinit coretemp_probe(struct platform_device *pdev)
208 struct coretemp_data *data;
209 struct cpuinfo_x86 *c = &cpu_data(pdev->id);
213 if (!(data = kzalloc(sizeof(struct coretemp_data), GFP_KERNEL))) {
215 dev_err(&pdev->dev, "Out of memory\n");
221 data->core_id = c->cpu_core_id;
223 data->name = "coretemp";
224 mutex_init(&data->update_lock);
226 /* test if we can access the THERM_STATUS MSR */
227 err = rdmsr_safe_on_cpu(data->id, MSR_IA32_THERM_STATUS, &eax, &edx);
230 "Unable to access THERM_STATUS MSR, giving up\n");
234 /* Check if we have problem with errata AE18 of Core processors:
235 Readings might stop update when processor visited too deep sleep,
236 fixed for stepping D0 (6EC).
239 if ((c->x86_model == 0xe) && (c->x86_mask < 0xc)) {
240 /* check for microcode update */
241 rdmsr_on_cpu(data->id, MSR_IA32_UCODE_REV, &eax, &edx);
245 "Errata AE18 not fixed, update BIOS or "
246 "microcode of the CPU!\n");
251 data->tjmax = adjust_tjmax(c, data->id, &pdev->dev);
252 platform_set_drvdata(pdev, data);
254 /* read the still undocumented IA32_TEMPERATURE_TARGET it exists
255 on older CPUs but not in this register */
257 if (c->x86_model > 0xe) {
258 err = rdmsr_safe_on_cpu(data->id, 0x1a2, &eax, &edx);
260 dev_warn(&pdev->dev, "Unable to read"
261 " IA32_TEMPERATURE_TARGET MSR\n");
263 data->ttarget = data->tjmax -
264 (((eax >> 8) & 0xff) * 1000);
265 err = device_create_file(&pdev->dev,
266 &sensor_dev_attr_temp1_max.dev_attr);
272 if ((err = sysfs_create_group(&pdev->dev.kobj, &coretemp_group)))
275 data->hwmon_dev = hwmon_device_register(&pdev->dev);
276 if (IS_ERR(data->hwmon_dev)) {
277 err = PTR_ERR(data->hwmon_dev);
278 dev_err(&pdev->dev, "Class registration failed (%d)\n",
286 sysfs_remove_group(&pdev->dev.kobj, &coretemp_group);
288 device_remove_file(&pdev->dev, &sensor_dev_attr_temp1_max.dev_attr);
295 static int __devexit coretemp_remove(struct platform_device *pdev)
297 struct coretemp_data *data = platform_get_drvdata(pdev);
299 hwmon_device_unregister(data->hwmon_dev);
300 sysfs_remove_group(&pdev->dev.kobj, &coretemp_group);
301 device_remove_file(&pdev->dev, &sensor_dev_attr_temp1_max.dev_attr);
302 platform_set_drvdata(pdev, NULL);
307 static struct platform_driver coretemp_driver = {
309 .owner = THIS_MODULE,
312 .probe = coretemp_probe,
313 .remove = __devexit_p(coretemp_remove),
317 struct list_head list;
318 struct platform_device *pdev;
322 static LIST_HEAD(pdev_list);
323 static DEFINE_MUTEX(pdev_list_mutex);
325 static int __cpuinit coretemp_device_add(unsigned int cpu)
328 struct platform_device *pdev;
329 struct pdev_entry *pdev_entry;
331 pdev = platform_device_alloc(DRVNAME, cpu);
334 printk(KERN_ERR DRVNAME ": Device allocation failed\n");
338 pdev_entry = kzalloc(sizeof(struct pdev_entry), GFP_KERNEL);
341 goto exit_device_put;
344 err = platform_device_add(pdev);
346 printk(KERN_ERR DRVNAME ": Device addition failed (%d)\n",
348 goto exit_device_free;
351 pdev_entry->pdev = pdev;
352 pdev_entry->cpu = cpu;
353 mutex_lock(&pdev_list_mutex);
354 list_add_tail(&pdev_entry->list, &pdev_list);
355 mutex_unlock(&pdev_list_mutex);
362 platform_device_put(pdev);
367 #ifdef CONFIG_HOTPLUG_CPU
368 static void coretemp_device_remove(unsigned int cpu)
370 struct pdev_entry *p, *n;
371 mutex_lock(&pdev_list_mutex);
372 list_for_each_entry_safe(p, n, &pdev_list, list) {
374 platform_device_unregister(p->pdev);
379 mutex_unlock(&pdev_list_mutex);
382 static int __cpuinit coretemp_cpu_callback(struct notifier_block *nfb,
383 unsigned long action, void *hcpu)
385 unsigned int cpu = (unsigned long) hcpu;
389 case CPU_DOWN_FAILED:
390 coretemp_device_add(cpu);
392 case CPU_DOWN_PREPARE:
393 coretemp_device_remove(cpu);
399 static struct notifier_block coretemp_cpu_notifier __refdata = {
400 .notifier_call = coretemp_cpu_callback,
402 #endif /* !CONFIG_HOTPLUG_CPU */
404 static int __init coretemp_init(void)
406 int i, err = -ENODEV;
407 struct pdev_entry *p, *n;
409 /* quick check if we run Intel */
410 if (cpu_data(0).x86_vendor != X86_VENDOR_INTEL)
413 err = platform_driver_register(&coretemp_driver);
417 for_each_online_cpu(i) {
418 struct cpuinfo_x86 *c = &cpu_data(i);
420 /* check if family 6, models 0xe, 0xf, 0x16, 0x17, 0x1A */
421 if ((c->cpuid_level < 0) || (c->x86 != 0x6) ||
422 !((c->x86_model == 0xe) || (c->x86_model == 0xf) ||
423 (c->x86_model == 0x16) || (c->x86_model == 0x17) ||
424 (c->x86_model == 0x1A))) {
426 /* supported CPU not found, but report the unknown
428 if ((c->x86 == 0x6) && (c->x86_model > 0xf))
429 printk(KERN_WARNING DRVNAME ": Unknown CPU "
430 "model %x\n", c->x86_model);
434 err = coretemp_device_add(i);
436 goto exit_devices_unreg;
438 if (list_empty(&pdev_list)) {
440 goto exit_driver_unreg;
443 #ifdef CONFIG_HOTPLUG_CPU
444 register_hotcpu_notifier(&coretemp_cpu_notifier);
449 mutex_lock(&pdev_list_mutex);
450 list_for_each_entry_safe(p, n, &pdev_list, list) {
451 platform_device_unregister(p->pdev);
455 mutex_unlock(&pdev_list_mutex);
457 platform_driver_unregister(&coretemp_driver);
462 static void __exit coretemp_exit(void)
464 struct pdev_entry *p, *n;
465 #ifdef CONFIG_HOTPLUG_CPU
466 unregister_hotcpu_notifier(&coretemp_cpu_notifier);
468 mutex_lock(&pdev_list_mutex);
469 list_for_each_entry_safe(p, n, &pdev_list, list) {
470 platform_device_unregister(p->pdev);
474 mutex_unlock(&pdev_list_mutex);
475 platform_driver_unregister(&coretemp_driver);
478 MODULE_AUTHOR("Rudolf Marek <r.marek@assembler.cz>");
479 MODULE_DESCRIPTION("Intel Core temperature monitor");
480 MODULE_LICENSE("GPL");
482 module_init(coretemp_init)
483 module_exit(coretemp_exit)