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
)