xref: /linux/drivers/hwmon/via-cputemp.c (revision 827634added7f38b7d724cab1dccdb2b004c13c3)
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 
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 
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 
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 
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 
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 		.name = DRVNAME,
209 	},
210 	.probe = via_cputemp_probe,
211 	.remove = via_cputemp_remove,
212 };
213 
214 struct pdev_entry {
215 	struct list_head list;
216 	struct platform_device *pdev;
217 	unsigned int cpu;
218 };
219 
220 static LIST_HEAD(pdev_list);
221 static DEFINE_MUTEX(pdev_list_mutex);
222 
223 static int via_cputemp_device_add(unsigned int cpu)
224 {
225 	int err;
226 	struct platform_device *pdev;
227 	struct pdev_entry *pdev_entry;
228 
229 	pdev = platform_device_alloc(DRVNAME, cpu);
230 	if (!pdev) {
231 		err = -ENOMEM;
232 		pr_err("Device allocation failed\n");
233 		goto exit;
234 	}
235 
236 	pdev_entry = kzalloc(sizeof(struct pdev_entry), GFP_KERNEL);
237 	if (!pdev_entry) {
238 		err = -ENOMEM;
239 		goto exit_device_put;
240 	}
241 
242 	err = platform_device_add(pdev);
243 	if (err) {
244 		pr_err("Device addition failed (%d)\n", err);
245 		goto exit_device_free;
246 	}
247 
248 	pdev_entry->pdev = pdev;
249 	pdev_entry->cpu = cpu;
250 	mutex_lock(&pdev_list_mutex);
251 	list_add_tail(&pdev_entry->list, &pdev_list);
252 	mutex_unlock(&pdev_list_mutex);
253 
254 	return 0;
255 
256 exit_device_free:
257 	kfree(pdev_entry);
258 exit_device_put:
259 	platform_device_put(pdev);
260 exit:
261 	return err;
262 }
263 
264 static void via_cputemp_device_remove(unsigned int cpu)
265 {
266 	struct pdev_entry *p;
267 
268 	mutex_lock(&pdev_list_mutex);
269 	list_for_each_entry(p, &pdev_list, list) {
270 		if (p->cpu == cpu) {
271 			platform_device_unregister(p->pdev);
272 			list_del(&p->list);
273 			mutex_unlock(&pdev_list_mutex);
274 			kfree(p);
275 			return;
276 		}
277 	}
278 	mutex_unlock(&pdev_list_mutex);
279 }
280 
281 static int via_cputemp_cpu_callback(struct notifier_block *nfb,
282 				    unsigned long action, void *hcpu)
283 {
284 	unsigned int cpu = (unsigned long) hcpu;
285 
286 	switch (action) {
287 	case CPU_ONLINE:
288 	case CPU_DOWN_FAILED:
289 		via_cputemp_device_add(cpu);
290 		break;
291 	case CPU_DOWN_PREPARE:
292 		via_cputemp_device_remove(cpu);
293 		break;
294 	}
295 	return NOTIFY_OK;
296 }
297 
298 static struct notifier_block via_cputemp_cpu_notifier __refdata = {
299 	.notifier_call = via_cputemp_cpu_callback,
300 };
301 
302 static const struct x86_cpu_id __initconst cputemp_ids[] = {
303 	{ X86_VENDOR_CENTAUR, 6, 0xa, }, /* C7 A */
304 	{ X86_VENDOR_CENTAUR, 6, 0xd, }, /* C7 D */
305 	{ X86_VENDOR_CENTAUR, 6, 0xf, }, /* Nano */
306 	{}
307 };
308 MODULE_DEVICE_TABLE(x86cpu, cputemp_ids);
309 
310 static int __init via_cputemp_init(void)
311 {
312 	int i, err;
313 
314 	if (!x86_match_cpu(cputemp_ids))
315 		return -ENODEV;
316 
317 	err = platform_driver_register(&via_cputemp_driver);
318 	if (err)
319 		goto exit;
320 
321 	cpu_notifier_register_begin();
322 	for_each_online_cpu(i) {
323 		struct cpuinfo_x86 *c = &cpu_data(i);
324 
325 		if (c->x86 != 6)
326 			continue;
327 
328 		if (c->x86_model < 0x0a)
329 			continue;
330 
331 		if (c->x86_model > 0x0f) {
332 			pr_warn("Unknown CPU model 0x%x\n", c->x86_model);
333 			continue;
334 		}
335 
336 		via_cputemp_device_add(i);
337 	}
338 
339 #ifndef CONFIG_HOTPLUG_CPU
340 	if (list_empty(&pdev_list)) {
341 		cpu_notifier_register_done();
342 		err = -ENODEV;
343 		goto exit_driver_unreg;
344 	}
345 #endif
346 
347 	__register_hotcpu_notifier(&via_cputemp_cpu_notifier);
348 	cpu_notifier_register_done();
349 	return 0;
350 
351 #ifndef CONFIG_HOTPLUG_CPU
352 exit_driver_unreg:
353 	platform_driver_unregister(&via_cputemp_driver);
354 #endif
355 exit:
356 	return err;
357 }
358 
359 static void __exit via_cputemp_exit(void)
360 {
361 	struct pdev_entry *p, *n;
362 
363 	cpu_notifier_register_begin();
364 	__unregister_hotcpu_notifier(&via_cputemp_cpu_notifier);
365 	mutex_lock(&pdev_list_mutex);
366 	list_for_each_entry_safe(p, n, &pdev_list, list) {
367 		platform_device_unregister(p->pdev);
368 		list_del(&p->list);
369 		kfree(p);
370 	}
371 	mutex_unlock(&pdev_list_mutex);
372 	cpu_notifier_register_done();
373 	platform_driver_unregister(&via_cputemp_driver);
374 }
375 
376 MODULE_AUTHOR("Harald Welte <HaraldWelte@viatech.com>");
377 MODULE_DESCRIPTION("VIA CPU temperature monitor");
378 MODULE_LICENSE("GPL");
379 
380 module_init(via_cputemp_init)
381 module_exit(via_cputemp_exit)
382