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Harald Welte70c38772009-12-16 21:38:28 +01001/*
2 * via-cputemp.c - Driver for VIA CPU core temperature monitoring
3 * Copyright (C) 2009 VIA Technologies, Inc.
4 *
5 * based on existing coretemp.c, which is
6 *
7 * Copyright (C) 2007 Rudolf Marek <r.marek@assembler.cz>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; version 2 of the License.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
21 * 02110-1301 USA.
22 */
23
24#include <linux/module.h>
25#include <linux/delay.h>
26#include <linux/init.h>
27#include <linux/slab.h>
28#include <linux/jiffies.h>
29#include <linux/hwmon.h>
30#include <linux/sysfs.h>
31#include <linux/hwmon-sysfs.h>
32#include <linux/err.h>
33#include <linux/mutex.h>
34#include <linux/list.h>
35#include <linux/platform_device.h>
36#include <linux/cpu.h>
37#include <asm/msr.h>
38#include <asm/processor.h>
39
40#define DRVNAME "via_cputemp"
41
H. Peter Anvinf2799412010-08-14 21:09:02 +020042enum { SHOW_TEMP, SHOW_LABEL, SHOW_NAME };
Harald Welte70c38772009-12-16 21:38:28 +010043
44/*
45 * Functions declaration
46 */
47
48struct via_cputemp_data {
49 struct device *hwmon_dev;
50 const char *name;
51 u32 id;
52 u32 msr;
53};
54
55/*
56 * Sysfs stuff
57 */
58
59static ssize_t show_name(struct device *dev, struct device_attribute
60 *devattr, char *buf)
61{
62 int ret;
63 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
64 struct via_cputemp_data *data = dev_get_drvdata(dev);
65
66 if (attr->index == SHOW_NAME)
67 ret = sprintf(buf, "%s\n", data->name);
68 else /* show label */
69 ret = sprintf(buf, "Core %d\n", data->id);
70 return ret;
71}
72
73static ssize_t show_temp(struct device *dev,
74 struct device_attribute *devattr, char *buf)
75{
76 struct via_cputemp_data *data = dev_get_drvdata(dev);
77 u32 eax, edx;
78 int err;
79
80 err = rdmsr_safe_on_cpu(data->id, data->msr, &eax, &edx);
81 if (err)
82 return -EAGAIN;
83
84 return sprintf(buf, "%lu\n", ((unsigned long)eax & 0xffffff) * 1000);
85}
86
87static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL,
88 SHOW_TEMP);
89static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, show_name, NULL, SHOW_LABEL);
90static SENSOR_DEVICE_ATTR(name, S_IRUGO, show_name, NULL, SHOW_NAME);
91
92static struct attribute *via_cputemp_attributes[] = {
93 &sensor_dev_attr_name.dev_attr.attr,
94 &sensor_dev_attr_temp1_label.dev_attr.attr,
95 &sensor_dev_attr_temp1_input.dev_attr.attr,
96 NULL
97};
98
99static const struct attribute_group via_cputemp_group = {
100 .attrs = via_cputemp_attributes,
101};
102
103static int __devinit via_cputemp_probe(struct platform_device *pdev)
104{
105 struct via_cputemp_data *data;
106 struct cpuinfo_x86 *c = &cpu_data(pdev->id);
107 int err;
108 u32 eax, edx;
109
110 data = kzalloc(sizeof(struct via_cputemp_data), GFP_KERNEL);
111 if (!data) {
112 err = -ENOMEM;
113 dev_err(&pdev->dev, "Out of memory\n");
114 goto exit;
115 }
116
117 data->id = pdev->id;
118 data->name = "via_cputemp";
119
120 switch (c->x86_model) {
121 case 0xA:
122 /* C7 A */
123 case 0xD:
124 /* C7 D */
125 data->msr = 0x1169;
126 break;
127 case 0xF:
128 /* Nano */
129 data->msr = 0x1423;
130 break;
131 default:
132 err = -ENODEV;
133 goto exit_free;
134 }
135
136 /* test if we can access the TEMPERATURE MSR */
137 err = rdmsr_safe_on_cpu(data->id, data->msr, &eax, &edx);
138 if (err) {
139 dev_err(&pdev->dev,
140 "Unable to access TEMPERATURE MSR, giving up\n");
141 goto exit_free;
142 }
143
144 platform_set_drvdata(pdev, data);
145
146 err = sysfs_create_group(&pdev->dev.kobj, &via_cputemp_group);
147 if (err)
148 goto exit_free;
149
150 data->hwmon_dev = hwmon_device_register(&pdev->dev);
151 if (IS_ERR(data->hwmon_dev)) {
152 err = PTR_ERR(data->hwmon_dev);
153 dev_err(&pdev->dev, "Class registration failed (%d)\n",
154 err);
155 goto exit_remove;
156 }
157
158 return 0;
159
160exit_remove:
161 sysfs_remove_group(&pdev->dev.kobj, &via_cputemp_group);
162exit_free:
163 platform_set_drvdata(pdev, NULL);
164 kfree(data);
165exit:
166 return err;
167}
168
169static int __devexit via_cputemp_remove(struct platform_device *pdev)
170{
171 struct via_cputemp_data *data = platform_get_drvdata(pdev);
172
173 hwmon_device_unregister(data->hwmon_dev);
174 sysfs_remove_group(&pdev->dev.kobj, &via_cputemp_group);
175 platform_set_drvdata(pdev, NULL);
176 kfree(data);
177 return 0;
178}
179
180static struct platform_driver via_cputemp_driver = {
181 .driver = {
182 .owner = THIS_MODULE,
183 .name = DRVNAME,
184 },
185 .probe = via_cputemp_probe,
186 .remove = __devexit_p(via_cputemp_remove),
187};
188
189struct pdev_entry {
190 struct list_head list;
191 struct platform_device *pdev;
192 unsigned int cpu;
193};
194
195static LIST_HEAD(pdev_list);
196static DEFINE_MUTEX(pdev_list_mutex);
197
198static int __cpuinit via_cputemp_device_add(unsigned int cpu)
199{
200 int err;
201 struct platform_device *pdev;
202 struct pdev_entry *pdev_entry;
203
204 pdev = platform_device_alloc(DRVNAME, cpu);
205 if (!pdev) {
206 err = -ENOMEM;
207 printk(KERN_ERR DRVNAME ": Device allocation failed\n");
208 goto exit;
209 }
210
211 pdev_entry = kzalloc(sizeof(struct pdev_entry), GFP_KERNEL);
212 if (!pdev_entry) {
213 err = -ENOMEM;
214 goto exit_device_put;
215 }
216
217 err = platform_device_add(pdev);
218 if (err) {
219 printk(KERN_ERR DRVNAME ": Device addition failed (%d)\n",
220 err);
221 goto exit_device_free;
222 }
223
224 pdev_entry->pdev = pdev;
225 pdev_entry->cpu = cpu;
226 mutex_lock(&pdev_list_mutex);
227 list_add_tail(&pdev_entry->list, &pdev_list);
228 mutex_unlock(&pdev_list_mutex);
229
230 return 0;
231
232exit_device_free:
233 kfree(pdev_entry);
234exit_device_put:
235 platform_device_put(pdev);
236exit:
237 return err;
238}
239
240#ifdef CONFIG_HOTPLUG_CPU
241static void via_cputemp_device_remove(unsigned int cpu)
242{
243 struct pdev_entry *p, *n;
244 mutex_lock(&pdev_list_mutex);
245 list_for_each_entry_safe(p, n, &pdev_list, list) {
246 if (p->cpu == cpu) {
247 platform_device_unregister(p->pdev);
248 list_del(&p->list);
249 kfree(p);
250 }
251 }
252 mutex_unlock(&pdev_list_mutex);
253}
254
255static int __cpuinit via_cputemp_cpu_callback(struct notifier_block *nfb,
256 unsigned long action, void *hcpu)
257{
258 unsigned int cpu = (unsigned long) hcpu;
259
260 switch (action) {
261 case CPU_ONLINE:
262 case CPU_DOWN_FAILED:
263 via_cputemp_device_add(cpu);
264 break;
265 case CPU_DOWN_PREPARE:
266 via_cputemp_device_remove(cpu);
267 break;
268 }
269 return NOTIFY_OK;
270}
271
272static struct notifier_block via_cputemp_cpu_notifier __refdata = {
273 .notifier_call = via_cputemp_cpu_callback,
274};
275#endif /* !CONFIG_HOTPLUG_CPU */
276
277static int __init via_cputemp_init(void)
278{
279 int i, err;
280 struct pdev_entry *p, *n;
281
282 if (cpu_data(0).x86_vendor != X86_VENDOR_CENTAUR) {
283 printk(KERN_DEBUG DRVNAME ": Not a VIA CPU\n");
284 err = -ENODEV;
285 goto exit;
286 }
287
288 err = platform_driver_register(&via_cputemp_driver);
289 if (err)
290 goto exit;
291
292 for_each_online_cpu(i) {
293 struct cpuinfo_x86 *c = &cpu_data(i);
294
295 if (c->x86 != 6)
296 continue;
297
298 if (c->x86_model < 0x0a)
299 continue;
300
301 if (c->x86_model > 0x0f) {
302 printk(KERN_WARNING DRVNAME ": Unknown CPU "
303 "model 0x%x\n", c->x86_model);
304 continue;
305 }
306
307 err = via_cputemp_device_add(i);
308 if (err)
309 goto exit_devices_unreg;
310 }
311 if (list_empty(&pdev_list)) {
312 err = -ENODEV;
313 goto exit_driver_unreg;
314 }
315
316#ifdef CONFIG_HOTPLUG_CPU
317 register_hotcpu_notifier(&via_cputemp_cpu_notifier);
318#endif
319 return 0;
320
321exit_devices_unreg:
322 mutex_lock(&pdev_list_mutex);
323 list_for_each_entry_safe(p, n, &pdev_list, list) {
324 platform_device_unregister(p->pdev);
325 list_del(&p->list);
326 kfree(p);
327 }
328 mutex_unlock(&pdev_list_mutex);
329exit_driver_unreg:
330 platform_driver_unregister(&via_cputemp_driver);
331exit:
332 return err;
333}
334
335static void __exit via_cputemp_exit(void)
336{
337 struct pdev_entry *p, *n;
338#ifdef CONFIG_HOTPLUG_CPU
339 unregister_hotcpu_notifier(&via_cputemp_cpu_notifier);
340#endif
341 mutex_lock(&pdev_list_mutex);
342 list_for_each_entry_safe(p, n, &pdev_list, list) {
343 platform_device_unregister(p->pdev);
344 list_del(&p->list);
345 kfree(p);
346 }
347 mutex_unlock(&pdev_list_mutex);
348 platform_driver_unregister(&via_cputemp_driver);
349}
350
351MODULE_AUTHOR("Harald Welte <HaraldWelte@viatech.com>");
352MODULE_DESCRIPTION("VIA CPU temperature monitor");
353MODULE_LICENSE("GPL");
354
355module_init(via_cputemp_init)
356module_exit(via_cputemp_exit)