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;
55 char valid; /* zero until following fields are valid */
56 unsigned long last_updated; /* in jiffies */
67 static ssize_t show_name(struct device *dev, struct device_attribute
71 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
72 struct coretemp_data *data = dev_get_drvdata(dev);
74 if (attr->index == SHOW_NAME)
75 ret = sprintf(buf, "%s\n", data->name);
77 ret = sprintf(buf, "Core %d\n", data->id);
81 static ssize_t show_alarm(struct device *dev, struct device_attribute
84 struct coretemp_data *data = coretemp_update_device(dev);
85 /* read the Out-of-spec log, never clear */
86 return sprintf(buf, "%d\n", data->alarm);
89 static ssize_t show_temp(struct device *dev,
90 struct device_attribute *devattr, char *buf)
92 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
93 struct coretemp_data *data = coretemp_update_device(dev);
96 if (attr->index == SHOW_TEMP)
97 err = data->valid ? sprintf(buf, "%d\n", data->temp) : -EAGAIN;
98 else if (attr->index == SHOW_TJMAX)
99 err = sprintf(buf, "%d\n", data->tjmax);
101 err = sprintf(buf, "%d\n", data->ttarget);
105 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL,
107 static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO, show_temp, NULL,
109 static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO, show_temp, NULL,
111 static DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL);
112 static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, show_name, NULL, SHOW_LABEL);
113 static SENSOR_DEVICE_ATTR(name, S_IRUGO, show_name, NULL, SHOW_NAME);
115 static struct attribute *coretemp_attributes[] = {
116 &sensor_dev_attr_name.dev_attr.attr,
117 &sensor_dev_attr_temp1_label.dev_attr.attr,
118 &dev_attr_temp1_crit_alarm.attr,
119 &sensor_dev_attr_temp1_input.dev_attr.attr,
120 &sensor_dev_attr_temp1_crit.dev_attr.attr,
124 static const struct attribute_group coretemp_group = {
125 .attrs = coretemp_attributes,
128 static struct coretemp_data *coretemp_update_device(struct device *dev)
130 struct coretemp_data *data = dev_get_drvdata(dev);
132 mutex_lock(&data->update_lock);
134 if (!data->valid || time_after(jiffies, data->last_updated + HZ)) {
138 rdmsr_on_cpu(data->id, MSR_IA32_THERM_STATUS, &eax, &edx);
139 data->alarm = (eax >> 5) & 1;
140 /* update only if data has been valid */
141 if (eax & 0x80000000) {
142 data->temp = data->tjmax - (((eax >> 16)
146 dev_dbg(dev, "Temperature data invalid (0x%x)\n", eax);
148 data->last_updated = jiffies;
151 mutex_unlock(&data->update_lock);
155 static int __devinit adjust_tjmax(struct cpuinfo_x86 *c, u32 id, struct device *dev)
157 /* The 100C is default for both mobile and non mobile CPUs */
160 int tjmax_ee = 85000;
165 /* Early chips have no MSR for TjMax */
167 if ((c->x86_model == 0xf) && (c->x86_mask < 4)) {
171 /* Atoms seems to have TjMax at 90C */
173 if (c->x86_model == 0x1c) {
178 if ((c->x86_model > 0xe) && (usemsr_ee)) {
181 /* Now we can detect the mobile CPU using Intel provided table
182 http://softwarecommunity.intel.com/Wiki/Mobility/720.htm
183 For Core2 cores, check MSR 0x17, bit 28 1 = Mobile CPU
186 err = rdmsr_safe_on_cpu(id, 0x17, &eax, &edx);
189 "Unable to access MSR 0x17, assuming desktop"
192 } else if (c->x86_model < 0x17 && !(eax & 0x10000000)) {
193 /* Trust bit 28 up to Penryn, I could not find any
194 documentation on that; if you happen to know
195 someone at Intel please ask */
198 /* Platform ID bits 52:50 (EDX starts at bit 32) */
199 platform_id = (edx >> 18) & 0x7;
201 /* Mobile Penryn CPU seems to be platform ID 7 or 5
203 if ((c->x86_model == 0x17) &&
204 ((platform_id == 5) || (platform_id == 7))) {
205 /* If MSR EE bit is set, set it to 90 degrees C,
206 otherwise 105 degrees C */
215 err = rdmsr_safe_on_cpu(id, 0xee, &eax, &edx);
218 "Unable to access MSR 0xEE, for Tjmax, left"
220 } else if (eax & 0x40000000) {
223 /* if we dont use msr EE it means we are desktop CPU (with exeception
225 } else if (tjmax == 100000) {
226 dev_warn(dev, "Using relative temperature scale!\n");
232 static int __devinit coretemp_probe(struct platform_device *pdev)
234 struct coretemp_data *data;
235 struct cpuinfo_x86 *c = &cpu_data(pdev->id);
239 if (!(data = kzalloc(sizeof(struct coretemp_data), GFP_KERNEL))) {
241 dev_err(&pdev->dev, "Out of memory\n");
246 data->name = "coretemp";
247 mutex_init(&data->update_lock);
249 /* test if we can access the THERM_STATUS MSR */
250 err = rdmsr_safe_on_cpu(data->id, MSR_IA32_THERM_STATUS, &eax, &edx);
253 "Unable to access THERM_STATUS MSR, giving up\n");
257 /* Check if we have problem with errata AE18 of Core processors:
258 Readings might stop update when processor visited too deep sleep,
259 fixed for stepping D0 (6EC).
262 if ((c->x86_model == 0xe) && (c->x86_mask < 0xc)) {
263 /* check for microcode update */
264 rdmsr_on_cpu(data->id, MSR_IA32_UCODE_REV, &eax, &edx);
268 "Errata AE18 not fixed, update BIOS or "
269 "microcode of the CPU!\n");
274 data->tjmax = adjust_tjmax(c, data->id, &pdev->dev);
275 platform_set_drvdata(pdev, data);
277 /* read the still undocumented IA32_TEMPERATURE_TARGET it exists
278 on older CPUs but not in this register, Atoms don't have it either */
280 if ((c->x86_model > 0xe) && (c->x86_model != 0x1c)) {
281 err = rdmsr_safe_on_cpu(data->id, 0x1a2, &eax, &edx);
283 dev_warn(&pdev->dev, "Unable to read"
284 " IA32_TEMPERATURE_TARGET MSR\n");
286 data->ttarget = data->tjmax -
287 (((eax >> 8) & 0xff) * 1000);
288 err = device_create_file(&pdev->dev,
289 &sensor_dev_attr_temp1_max.dev_attr);
295 if ((err = sysfs_create_group(&pdev->dev.kobj, &coretemp_group)))
298 data->hwmon_dev = hwmon_device_register(&pdev->dev);
299 if (IS_ERR(data->hwmon_dev)) {
300 err = PTR_ERR(data->hwmon_dev);
301 dev_err(&pdev->dev, "Class registration failed (%d)\n",
309 sysfs_remove_group(&pdev->dev.kobj, &coretemp_group);
311 device_remove_file(&pdev->dev, &sensor_dev_attr_temp1_max.dev_attr);
318 static int __devexit coretemp_remove(struct platform_device *pdev)
320 struct coretemp_data *data = platform_get_drvdata(pdev);
322 hwmon_device_unregister(data->hwmon_dev);
323 sysfs_remove_group(&pdev->dev.kobj, &coretemp_group);
324 device_remove_file(&pdev->dev, &sensor_dev_attr_temp1_max.dev_attr);
325 platform_set_drvdata(pdev, NULL);
330 static struct platform_driver coretemp_driver = {
332 .owner = THIS_MODULE,
335 .probe = coretemp_probe,
336 .remove = __devexit_p(coretemp_remove),
340 struct list_head list;
341 struct platform_device *pdev;
345 static LIST_HEAD(pdev_list);
346 static DEFINE_MUTEX(pdev_list_mutex);
348 static int __cpuinit coretemp_device_add(unsigned int cpu)
351 struct platform_device *pdev;
352 struct pdev_entry *pdev_entry;
354 pdev = platform_device_alloc(DRVNAME, cpu);
357 printk(KERN_ERR DRVNAME ": Device allocation failed\n");
361 pdev_entry = kzalloc(sizeof(struct pdev_entry), GFP_KERNEL);
364 goto exit_device_put;
367 err = platform_device_add(pdev);
369 printk(KERN_ERR DRVNAME ": Device addition failed (%d)\n",
371 goto exit_device_free;
374 pdev_entry->pdev = pdev;
375 pdev_entry->cpu = cpu;
376 mutex_lock(&pdev_list_mutex);
377 list_add_tail(&pdev_entry->list, &pdev_list);
378 mutex_unlock(&pdev_list_mutex);
385 platform_device_put(pdev);
390 #ifdef CONFIG_HOTPLUG_CPU
391 static void coretemp_device_remove(unsigned int cpu)
393 struct pdev_entry *p, *n;
394 mutex_lock(&pdev_list_mutex);
395 list_for_each_entry_safe(p, n, &pdev_list, list) {
397 platform_device_unregister(p->pdev);
402 mutex_unlock(&pdev_list_mutex);
405 static int __cpuinit coretemp_cpu_callback(struct notifier_block *nfb,
406 unsigned long action, void *hcpu)
408 unsigned int cpu = (unsigned long) hcpu;
412 case CPU_DOWN_FAILED:
413 coretemp_device_add(cpu);
415 case CPU_DOWN_PREPARE:
416 coretemp_device_remove(cpu);
422 static struct notifier_block coretemp_cpu_notifier __refdata = {
423 .notifier_call = coretemp_cpu_callback,
425 #endif /* !CONFIG_HOTPLUG_CPU */
427 static int __init coretemp_init(void)
429 int i, err = -ENODEV;
430 struct pdev_entry *p, *n;
432 /* quick check if we run Intel */
433 if (cpu_data(0).x86_vendor != X86_VENDOR_INTEL)
436 err = platform_driver_register(&coretemp_driver);
440 for_each_online_cpu(i) {
441 struct cpuinfo_x86 *c = &cpu_data(i);
443 /* check if family 6, models 0xe (Pentium M DC),
444 0xf (Core 2 DC 65nm), 0x16 (Core 2 SC 65nm),
445 0x17 (Penryn 45nm), 0x1a (Nehalem), 0x1c (Atom),
447 if ((c->cpuid_level < 0) || (c->x86 != 0x6) ||
448 !((c->x86_model == 0xe) || (c->x86_model == 0xf) ||
449 (c->x86_model == 0x16) || (c->x86_model == 0x17) ||
450 (c->x86_model == 0x1a) || (c->x86_model == 0x1c) ||
451 (c->x86_model == 0x1e))) {
453 /* supported CPU not found, but report the unknown
455 if ((c->x86 == 0x6) && (c->x86_model > 0xf))
456 printk(KERN_WARNING DRVNAME ": Unknown CPU "
457 "model %x\n", c->x86_model);
461 err = coretemp_device_add(i);
463 goto exit_devices_unreg;
465 if (list_empty(&pdev_list)) {
467 goto exit_driver_unreg;
470 #ifdef CONFIG_HOTPLUG_CPU
471 register_hotcpu_notifier(&coretemp_cpu_notifier);
476 mutex_lock(&pdev_list_mutex);
477 list_for_each_entry_safe(p, n, &pdev_list, list) {
478 platform_device_unregister(p->pdev);
482 mutex_unlock(&pdev_list_mutex);
484 platform_driver_unregister(&coretemp_driver);
489 static void __exit coretemp_exit(void)
491 struct pdev_entry *p, *n;
492 #ifdef CONFIG_HOTPLUG_CPU
493 unregister_hotcpu_notifier(&coretemp_cpu_notifier);
495 mutex_lock(&pdev_list_mutex);
496 list_for_each_entry_safe(p, n, &pdev_list, list) {
497 platform_device_unregister(p->pdev);
501 mutex_unlock(&pdev_list_mutex);
502 platform_driver_unregister(&coretemp_driver);
505 MODULE_AUTHOR("Rudolf Marek <r.marek@assembler.cz>");
506 MODULE_DESCRIPTION("Intel Core temperature monitor");
507 MODULE_LICENSE("GPL");
509 module_init(coretemp_init)
510 module_exit(coretemp_exit)