1 /*
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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
25
26 #include <linux/module.h>
27 #include <linux/init.h>
28 #include <linux/slab.h>
29 #include <linux/hwmon.h>
30 #include <linux/hwmon-vid.h>
31 #include <linux/sysfs.h>
32 #include <linux/hwmon-sysfs.h>
33 #include <linux/err.h>
34 #include <linux/mutex.h>
35 #include <linux/list.h>
36 #include <linux/platform_device.h>
37 #include <linux/cpu.h>
38 #include <asm/msr.h>
39 #include <asm/processor.h>
40 #include <asm/cpu_device_id.h>
41
42 #define DRVNAME "via_cputemp"
43
44 enum { SHOW_TEMP, SHOW_LABEL, SHOW_NAME };
45
46 /*
47 * Functions declaration
48 */
49
50 struct via_cputemp_data {
51 struct device *hwmon_dev;
52 const char *name;
53 u8 vrm;
54 u32 id;
55 u32 msr_temp;
56 u32 msr_vid;
57 };
58
59 /*
60 * Sysfs stuff
61 */
62
show_name(struct device * dev,struct device_attribute * devattr,char * buf)63 static ssize_t show_name(struct device *dev, struct device_attribute
64 *devattr, char *buf)
65 {
66 int ret;
67 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
68 struct via_cputemp_data *data = dev_get_drvdata(dev);
69
70 if (attr->index == SHOW_NAME)
71 ret = sprintf(buf, "%s\n", data->name);
72 else /* show label */
73 ret = sprintf(buf, "Core %d\n", data->id);
74 return ret;
75 }
76
show_temp(struct device * dev,struct device_attribute * devattr,char * buf)77 static ssize_t show_temp(struct device *dev,
78 struct device_attribute *devattr, char *buf)
79 {
80 struct via_cputemp_data *data = dev_get_drvdata(dev);
81 u32 eax, edx;
82 int err;
83
84 err = rdmsr_safe_on_cpu(data->id, data->msr_temp, &eax, &edx);
85 if (err)
86 return -EAGAIN;
87
88 return sprintf(buf, "%lu\n", ((unsigned long)eax & 0xffffff) * 1000);
89 }
90
show_cpu_vid(struct device * dev,struct device_attribute * devattr,char * buf)91 static ssize_t show_cpu_vid(struct device *dev,
92 struct device_attribute *devattr, char *buf)
93 {
94 struct via_cputemp_data *data = dev_get_drvdata(dev);
95 u32 eax, edx;
96 int err;
97
98 err = rdmsr_safe_on_cpu(data->id, data->msr_vid, &eax, &edx);
99 if (err)
100 return -EAGAIN;
101
102 return sprintf(buf, "%d\n", vid_from_reg(~edx & 0x7f, data->vrm));
103 }
104
105 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL,
106 SHOW_TEMP);
107 static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, show_name, NULL, SHOW_LABEL);
108 static SENSOR_DEVICE_ATTR(name, S_IRUGO, show_name, NULL, SHOW_NAME);
109
110 static struct attribute *via_cputemp_attributes[] = {
111 &sensor_dev_attr_name.dev_attr.attr,
112 &sensor_dev_attr_temp1_label.dev_attr.attr,
113 &sensor_dev_attr_temp1_input.dev_attr.attr,
114 NULL
115 };
116
117 static const struct attribute_group via_cputemp_group = {
118 .attrs = via_cputemp_attributes,
119 };
120
121 /* Optional attributes */
122 static DEVICE_ATTR(cpu0_vid, S_IRUGO, show_cpu_vid, NULL);
123
via_cputemp_probe(struct platform_device * pdev)124 static int via_cputemp_probe(struct platform_device *pdev)
125 {
126 struct via_cputemp_data *data;
127 struct cpuinfo_x86 *c = &cpu_data(pdev->id);
128 int err;
129 u32 eax, edx;
130
131 data = devm_kzalloc(&pdev->dev, sizeof(struct via_cputemp_data),
132 GFP_KERNEL);
133 if (!data)
134 return -ENOMEM;
135
136 data->id = pdev->id;
137 data->name = "via_cputemp";
138
139 switch (c->x86_model) {
140 case 0xA:
141 /* C7 A */
142 case 0xD:
143 /* C7 D */
144 data->msr_temp = 0x1169;
145 data->msr_vid = 0x198;
146 break;
147 case 0xF:
148 /* Nano */
149 data->msr_temp = 0x1423;
150 break;
151 default:
152 return -ENODEV;
153 }
154
155 /* test if we can access the TEMPERATURE MSR */
156 err = rdmsr_safe_on_cpu(data->id, data->msr_temp, &eax, &edx);
157 if (err) {
158 dev_err(&pdev->dev,
159 "Unable to access TEMPERATURE MSR, giving up\n");
160 return err;
161 }
162
163 platform_set_drvdata(pdev, data);
164
165 err = sysfs_create_group(&pdev->dev.kobj, &via_cputemp_group);
166 if (err)
167 return err;
168
169 if (data->msr_vid)
170 data->vrm = vid_which_vrm();
171
172 if (data->vrm) {
173 err = device_create_file(&pdev->dev, &dev_attr_cpu0_vid);
174 if (err)
175 goto exit_remove;
176 }
177
178 data->hwmon_dev = hwmon_device_register(&pdev->dev);
179 if (IS_ERR(data->hwmon_dev)) {
180 err = PTR_ERR(data->hwmon_dev);
181 dev_err(&pdev->dev, "Class registration failed (%d)\n",
182 err);
183 goto exit_remove;
184 }
185
186 return 0;
187
188 exit_remove:
189 if (data->vrm)
190 device_remove_file(&pdev->dev, &dev_attr_cpu0_vid);
191 sysfs_remove_group(&pdev->dev.kobj, &via_cputemp_group);
192 return err;
193 }
194
via_cputemp_remove(struct platform_device * pdev)195 static int via_cputemp_remove(struct platform_device *pdev)
196 {
197 struct via_cputemp_data *data = platform_get_drvdata(pdev);
198
199 hwmon_device_unregister(data->hwmon_dev);
200 if (data->vrm)
201 device_remove_file(&pdev->dev, &dev_attr_cpu0_vid);
202 sysfs_remove_group(&pdev->dev.kobj, &via_cputemp_group);
203 return 0;
204 }
205
206 static struct platform_driver via_cputemp_driver = {
207 .driver = {
208 .owner = THIS_MODULE,
209 .name = DRVNAME,
210 },
211 .probe = via_cputemp_probe,
212 .remove = via_cputemp_remove,
213 };
214
215 struct pdev_entry {
216 struct list_head list;
217 struct platform_device *pdev;
218 unsigned int cpu;
219 };
220
221 static LIST_HEAD(pdev_list);
222 static DEFINE_MUTEX(pdev_list_mutex);
223
via_cputemp_device_add(unsigned int cpu)224 static int __cpuinit via_cputemp_device_add(unsigned int cpu)
225 {
226 int err;
227 struct platform_device *pdev;
228 struct pdev_entry *pdev_entry;
229
230 pdev = platform_device_alloc(DRVNAME, cpu);
231 if (!pdev) {
232 err = -ENOMEM;
233 pr_err("Device allocation failed\n");
234 goto exit;
235 }
236
237 pdev_entry = kzalloc(sizeof(struct pdev_entry), GFP_KERNEL);
238 if (!pdev_entry) {
239 err = -ENOMEM;
240 goto exit_device_put;
241 }
242
243 err = platform_device_add(pdev);
244 if (err) {
245 pr_err("Device addition failed (%d)\n", err);
246 goto exit_device_free;
247 }
248
249 pdev_entry->pdev = pdev;
250 pdev_entry->cpu = cpu;
251 mutex_lock(&pdev_list_mutex);
252 list_add_tail(&pdev_entry->list, &pdev_list);
253 mutex_unlock(&pdev_list_mutex);
254
255 return 0;
256
257 exit_device_free:
258 kfree(pdev_entry);
259 exit_device_put:
260 platform_device_put(pdev);
261 exit:
262 return err;
263 }
264
via_cputemp_device_remove(unsigned int cpu)265 static void __cpuinit via_cputemp_device_remove(unsigned int cpu)
266 {
267 struct pdev_entry *p;
268
269 mutex_lock(&pdev_list_mutex);
270 list_for_each_entry(p, &pdev_list, list) {
271 if (p->cpu == cpu) {
272 platform_device_unregister(p->pdev);
273 list_del(&p->list);
274 mutex_unlock(&pdev_list_mutex);
275 kfree(p);
276 return;
277 }
278 }
279 mutex_unlock(&pdev_list_mutex);
280 }
281
via_cputemp_cpu_callback(struct notifier_block * nfb,unsigned long action,void * hcpu)282 static int __cpuinit via_cputemp_cpu_callback(struct notifier_block *nfb,
283 unsigned long action, void *hcpu)
284 {
285 unsigned int cpu = (unsigned long) hcpu;
286
287 switch (action) {
288 case CPU_ONLINE:
289 case CPU_DOWN_FAILED:
290 via_cputemp_device_add(cpu);
291 break;
292 case CPU_DOWN_PREPARE:
293 via_cputemp_device_remove(cpu);
294 break;
295 }
296 return NOTIFY_OK;
297 }
298
299 static struct notifier_block via_cputemp_cpu_notifier __refdata = {
300 .notifier_call = via_cputemp_cpu_callback,
301 };
302
303 static const struct x86_cpu_id __initconst cputemp_ids[] = {
304 { X86_VENDOR_CENTAUR, 6, 0xa, }, /* C7 A */
305 { X86_VENDOR_CENTAUR, 6, 0xd, }, /* C7 D */
306 { X86_VENDOR_CENTAUR, 6, 0xf, }, /* Nano */
307 {}
308 };
309 MODULE_DEVICE_TABLE(x86cpu, cputemp_ids);
310
via_cputemp_init(void)311 static int __init via_cputemp_init(void)
312 {
313 int i, err;
314
315 if (!x86_match_cpu(cputemp_ids))
316 return -ENODEV;
317
318 err = platform_driver_register(&via_cputemp_driver);
319 if (err)
320 goto exit;
321
322 get_online_cpus();
323 for_each_online_cpu(i) {
324 struct cpuinfo_x86 *c = &cpu_data(i);
325
326 if (c->x86 != 6)
327 continue;
328
329 if (c->x86_model < 0x0a)
330 continue;
331
332 if (c->x86_model > 0x0f) {
333 pr_warn("Unknown CPU model 0x%x\n", c->x86_model);
334 continue;
335 }
336
337 via_cputemp_device_add(i);
338 }
339
340 #ifndef CONFIG_HOTPLUG_CPU
341 if (list_empty(&pdev_list)) {
342 put_online_cpus();
343 err = -ENODEV;
344 goto exit_driver_unreg;
345 }
346 #endif
347
348 register_hotcpu_notifier(&via_cputemp_cpu_notifier);
349 put_online_cpus();
350 return 0;
351
352 #ifndef CONFIG_HOTPLUG_CPU
353 exit_driver_unreg:
354 platform_driver_unregister(&via_cputemp_driver);
355 #endif
356 exit:
357 return err;
358 }
359
via_cputemp_exit(void)360 static void __exit via_cputemp_exit(void)
361 {
362 struct pdev_entry *p, *n;
363
364 get_online_cpus();
365 unregister_hotcpu_notifier(&via_cputemp_cpu_notifier);
366 mutex_lock(&pdev_list_mutex);
367 list_for_each_entry_safe(p, n, &pdev_list, list) {
368 platform_device_unregister(p->pdev);
369 list_del(&p->list);
370 kfree(p);
371 }
372 mutex_unlock(&pdev_list_mutex);
373 put_online_cpus();
374 platform_driver_unregister(&via_cputemp_driver);
375 }
376
377 MODULE_AUTHOR("Harald Welte <HaraldWelte@viatech.com>");
378 MODULE_DESCRIPTION("VIA CPU temperature monitor");
379 MODULE_LICENSE("GPL");
380
381 module_init(via_cputemp_init)
382 module_exit(via_cputemp_exit)
383