summaryrefslogtreecommitdiffstats
path: root/drivers/hwmon/via-cputemp.c
blob: 7442cf7548563841765631f588cdfc480ef7ff42 (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
/*
 * via-cputemp.c - Driver for VIA CPU core temperature monitoring
 * Copyright (C) 2009 VIA Technologies, Inc.
 *
 * based on existing coretemp.c, which is
 *
 * Copyright (C) 2007 Rudolf Marek <r.marek@assembler.cz>
 *
 * 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	"via_cputemp"

enum { SHOW_TEMP, SHOW_LABEL, SHOW_NAME } SHOW;

/*
 * Functions declaration
 */

struct via_cputemp_data {
	struct device *hwmon_dev;
	const char *name;
	u32 id;
	u32 msr;
};

/*
 * 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 via_cputemp_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_temp(struct device *dev,
			 struct device_attribute *devattr, char *buf)
{
	struct via_cputemp_data *data = dev_get_drvdata(dev);
	u32 eax, edx;
	int err;

	err = rdmsr_safe_on_cpu(data->id, data->msr, &eax, &edx);
	if (err)
		return -EAGAIN;

	return sprintf(buf, "%lu\n", ((unsigned long)eax & 0xffffff) * 1000);
}

static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL,
			  SHOW_TEMP);
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 *via_cputemp_attributes[] = {
	&sensor_dev_attr_name.dev_attr.attr,
	&sensor_dev_attr_temp1_label.dev_attr.attr,
	&sensor_dev_attr_temp1_input.dev_attr.attr,
	NULL
};

static const struct attribute_group via_cputemp_group = {
	.attrs = via_cputemp_attributes,
};

static int __devinit via_cputemp_probe(struct platform_device *pdev)
{
	struct via_cputemp_data *data;
	struct cpuinfo_x86 *c = &cpu_data(pdev->id);
	int err;
	u32 eax, edx;

	data = kzalloc(sizeof(struct via_cputemp_data), GFP_KERNEL);
	if (!data) {
		err = -ENOMEM;
		dev_err(&pdev->dev, "Out of memory\n");
		goto exit;
	}

	data->id = pdev->id;
	data->name = "via_cputemp";

	switch (c->x86_model) {
	case 0xA:
		/* C7 A */
	case 0xD:
		/* C7 D */
		data->msr = 0x1169;
		break;
	case 0xF:
		/* Nano */
		data->msr = 0x1423;
		break;
	default:
		err = -ENODEV;
		goto exit_free;
	}

	/* test if we can access the TEMPERATURE MSR */
	err = rdmsr_safe_on_cpu(data->id, data->msr, &eax, &edx);
	if (err) {
		dev_err(&pdev->dev,
			"Unable to access TEMPERATURE MSR, giving up\n");
		goto exit_free;
	}

	platform_set_drvdata(pdev, data);

	err = sysfs_create_group(&pdev->dev.kobj, &via_cputemp_group);
	if (err)
		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_remove;
	}

	return 0;

exit_remove:
	sysfs_remove_group(&pdev->dev.kobj, &via_cputemp_group);
exit_free:
	platform_set_drvdata(pdev, NULL);
	kfree(data);
exit:
	return err;
}

static int __devexit via_cputemp_remove(struct platform_device *pdev)
{
	struct via_cputemp_data *data = platform_get_drvdata(pdev);

	hwmon_device_unregister(data->hwmon_dev);
	sysfs_remove_group(&pdev->dev.kobj, &via_cputemp_group);
	platform_set_drvdata(pdev, NULL);
	kfree(data);
	return 0;
}

static struct platform_driver via_cputemp_driver = {
	.driver = {
		.owner = THIS_MODULE,
		.name = DRVNAME,
	},
	.probe = via_cputemp_probe,
	.remove = __devexit_p(via_cputemp_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 via_cputemp_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 via_cputemp_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 __cpuinit via_cputemp_cpu_callback(struct notifier_block *nfb,
				 unsigned long action, void *hcpu)
{
	unsigned int cpu = (unsigned long) hcpu;

	switch (action) {
	case CPU_ONLINE:
	case CPU_DOWN_FAILED:
		via_cputemp_device_add(cpu);
		break;
	case CPU_DOWN_PREPARE:
		via_cputemp_device_remove(cpu);
		break;
	}
	return NOTIFY_OK;
}

static struct notifier_block via_cputemp_cpu_notifier __refdata = {
	.notifier_call = via_cputemp_cpu_callback,
};
#endif				/* !CONFIG_HOTPLUG_CPU */

static int __init via_cputemp_init(void)
{
	int i, err;
	struct pdev_entry *p, *n;

	if (cpu_data(0).x86_vendor != X86_VENDOR_CENTAUR) {
		printk(KERN_DEBUG DRVNAME ": Not a VIA CPU\n");
		err = -ENODEV;
		goto exit;
	}

	err = platform_driver_register(&via_cputemp_driver);
	if (err)
		goto exit;

	for_each_online_cpu(i) {
		struct cpuinfo_x86 *c = &cpu_data(i);

		if (c->x86 != 6)
			continue;

		if (c->x86_model < 0x0a)
			continue;

		if (c->x86_model > 0x0f) {
			printk(KERN_WARNING DRVNAME ": Unknown CPU "
				"model 0x%x\n", c->x86_model);
			continue;
		}

		err = via_cputemp_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(&via_cputemp_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(&via_cputemp_driver);
exit:
	return err;
}

static void __exit via_cputemp_exit(void)
{
	struct pdev_entry *p, *n;
#ifdef CONFIG_HOTPLUG_CPU
	unregister_hotcpu_notifier(&via_cputemp_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(&via_cputemp_driver);
}

MODULE_AUTHOR("Harald Welte <HaraldWelte@viatech.com>");
MODULE_DESCRIPTION("VIA CPU temperature monitor");
MODULE_LICENSE("GPL");

module_init(via_cputemp_init)
module_exit(via_cputemp_exit)