aboutsummaryrefslogtreecommitdiff
path: root/drivers/hwmon/coretemp.c
blob: 1a0ff8d42bb2f967b4e2362a37f4712e7748f669 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
/*
 * 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 device *hwmon_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;
};

/*
 * 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;
	}

	/* Check if we have problem with errata AE18 of Core processors:
	   Readings might stop update when processor visited too deep sleep,
	   fixed for stepping D0 (6EC).
	*/

	if ((c->x86_model == 0xe) && (c->x86_mask < 0xc)) {
		/* check for microcode update */
		rdmsr_on_cpu(data->id, MSR_IA32_UCODE_REV, &eax, &edx);
		if (edx < 0x39) {
			err = -ENODEV;
			dev_err(&pdev->dev,
				"Errata AE18 not fixed, update BIOS or "
				"microcode of the CPU!\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;
		}
	}

	/* Intel says that above should not work for desktop Core2 processors,
	   but it seems to work. There is no other way how get the absolute
	   readings. Warn the user about this. First check if are desktop,
	   bit 50 of MSR_IA32_PLATFORM_ID should be 0.
	*/

	rdmsr_safe_on_cpu(data->id, MSR_IA32_PLATFORM_ID, &eax, &edx);

	if ((c->x86_model == 0xf) && (!(edx & 0x00040000))) {
		dev_warn(&pdev->dev, "Using undocumented features, absolute "
			 "temperature might be wrong!\n");
	}

	platform_set_drvdata(pdev, data);

	if ((err = sysfs_create_group(&pdev->dev.kobj, &coretemp_group)))
		goto exit_free;

	data->hwmon_dev = hwmon_device_register(&pdev->dev);
	if (IS_ERR(data->hwmon_dev)) {
		err = PTR_ERR(data->hwmon_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->hwmon_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
static 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 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;

	/* 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)