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
44enum { SHOW_TEMP, SHOW_LABEL, SHOW_NAME };
45
46/*
47 * Functions declaration
48 */
49
50struct 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
63static ssize_t name_show(struct device *dev, struct device_attribute *devattr,
64 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
77static ssize_t temp_show(struct device *dev, struct device_attribute *devattr,
78 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
91static ssize_t cpu0_vid_show(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
105static SENSOR_DEVICE_ATTR_RO(temp1_input, temp, SHOW_TEMP);
106static SENSOR_DEVICE_ATTR_RO(temp1_label, name, SHOW_LABEL);
107static SENSOR_DEVICE_ATTR_RO(name, name, SHOW_NAME);
108
109static struct attribute *via_cputemp_attributes[] = {
110 &sensor_dev_attr_name.dev_attr.attr,
111 &sensor_dev_attr_temp1_label.dev_attr.attr,
112 &sensor_dev_attr_temp1_input.dev_attr.attr,
113 NULL
114};
115
116static const struct attribute_group via_cputemp_group = {
117 .attrs = via_cputemp_attributes,
118};
119
120/* Optional attributes */
121static DEVICE_ATTR_RO(cpu0_vid);
122
123static int via_cputemp_probe(struct platform_device *pdev)
124{
125 struct via_cputemp_data *data;
126 struct cpuinfo_x86 *c = &cpu_data(pdev->id);
127 int err;
128 u32 eax, edx;
129
130 data = devm_kzalloc(&pdev->dev, sizeof(struct via_cputemp_data),
131 GFP_KERNEL);
132 if (!data)
133 return -ENOMEM;
134
135 data->id = pdev->id;
136 data->name = "via_cputemp";
137
138 if (c->x86 == 7) {
139 data->msr_temp = 0x1423;
140 } else {
141 switch (c->x86_model) {
142 case 0xA:
143 /* C7 A */
144 case 0xD:
145 /* C7 D */
146 data->msr_temp = 0x1169;
147 data->msr_vid = 0x198;
148 break;
149 case 0xF:
150 /* Nano */
151 data->msr_temp = 0x1423;
152 break;
153 default:
154 return -ENODEV;
155 }
156 }
157
158 /* test if we can access the TEMPERATURE MSR */
159 err = rdmsr_safe_on_cpu(data->id, data->msr_temp, &eax, &edx);
160 if (err) {
161 dev_err(&pdev->dev,
162 "Unable to access TEMPERATURE MSR, giving up\n");
163 return err;
164 }
165
166 platform_set_drvdata(pdev, data);
167
168 err = sysfs_create_group(&pdev->dev.kobj, &via_cputemp_group);
169 if (err)
170 return err;
171
172 if (data->msr_vid)
173 data->vrm = vid_which_vrm();
174
175 if (data->vrm) {
176 err = device_create_file(&pdev->dev, &dev_attr_cpu0_vid);
177 if (err)
178 goto exit_remove;
179 }
180
181 data->hwmon_dev = hwmon_device_register(&pdev->dev);
182 if (IS_ERR(data->hwmon_dev)) {
183 err = PTR_ERR(data->hwmon_dev);
184 dev_err(&pdev->dev, "Class registration failed (%d)\n",
185 err);
186 goto exit_remove;
187 }
188
189 return 0;
190
191exit_remove:
192 if (data->vrm)
193 device_remove_file(&pdev->dev, &dev_attr_cpu0_vid);
194 sysfs_remove_group(&pdev->dev.kobj, &via_cputemp_group);
195 return err;
196}
197
198static int via_cputemp_remove(struct platform_device *pdev)
199{
200 struct via_cputemp_data *data = platform_get_drvdata(pdev);
201
202 hwmon_device_unregister(data->hwmon_dev);
203 if (data->vrm)
204 device_remove_file(&pdev->dev, &dev_attr_cpu0_vid);
205 sysfs_remove_group(&pdev->dev.kobj, &via_cputemp_group);
206 return 0;
207}
208
209static struct platform_driver via_cputemp_driver = {
210 .driver = {
211 .name = DRVNAME,
212 },
213 .probe = via_cputemp_probe,
214 .remove = via_cputemp_remove,
215};
216
217struct pdev_entry {
218 struct list_head list;
219 struct platform_device *pdev;
220 unsigned int cpu;
221};
222
223static LIST_HEAD(pdev_list);
224static DEFINE_MUTEX(pdev_list_mutex);
225
226static int via_cputemp_online(unsigned int cpu)
227{
228 int err;
229 struct platform_device *pdev;
230 struct pdev_entry *pdev_entry;
231
232 pdev = platform_device_alloc(DRVNAME, cpu);
233 if (!pdev) {
234 err = -ENOMEM;
235 pr_err("Device allocation failed\n");
236 goto exit;
237 }
238
239 pdev_entry = kzalloc(sizeof(struct pdev_entry), GFP_KERNEL);
240 if (!pdev_entry) {
241 err = -ENOMEM;
242 goto exit_device_put;
243 }
244
245 err = platform_device_add(pdev);
246 if (err) {
247 pr_err("Device addition failed (%d)\n", err);
248 goto exit_device_free;
249 }
250
251 pdev_entry->pdev = pdev;
252 pdev_entry->cpu = cpu;
253 mutex_lock(&pdev_list_mutex);
254 list_add_tail(&pdev_entry->list, &pdev_list);
255 mutex_unlock(&pdev_list_mutex);
256
257 return 0;
258
259exit_device_free:
260 kfree(pdev_entry);
261exit_device_put:
262 platform_device_put(pdev);
263exit:
264 return err;
265}
266
267static int via_cputemp_down_prep(unsigned int cpu)
268{
269 struct pdev_entry *p;
270
271 mutex_lock(&pdev_list_mutex);
272 list_for_each_entry(p, &pdev_list, list) {
273 if (p->cpu == cpu) {
274 platform_device_unregister(p->pdev);
275 list_del(&p->list);
276 mutex_unlock(&pdev_list_mutex);
277 kfree(p);
278 return 0;
279 }
280 }
281 mutex_unlock(&pdev_list_mutex);
282 return 0;
283}
284
285static const struct x86_cpu_id __initconst cputemp_ids[] = {
286 { X86_VENDOR_CENTAUR, 6, 0xa, }, /* C7 A */
287 { X86_VENDOR_CENTAUR, 6, 0xd, }, /* C7 D */
288 { X86_VENDOR_CENTAUR, 6, 0xf, }, /* Nano */
289 { X86_VENDOR_CENTAUR, 7, X86_MODEL_ANY, },
290 {}
291};
292MODULE_DEVICE_TABLE(x86cpu, cputemp_ids);
293
294static enum cpuhp_state via_temp_online;
295
296static int __init via_cputemp_init(void)
297{
298 int err;
299
300 if (!x86_match_cpu(cputemp_ids))
301 return -ENODEV;
302
303 err = platform_driver_register(&via_cputemp_driver);
304 if (err)
305 goto exit;
306
307 err = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "hwmon/via:online",
308 via_cputemp_online, via_cputemp_down_prep);
309 if (err < 0)
310 goto exit_driver_unreg;
311 via_temp_online = err;
312
313#ifndef CONFIG_HOTPLUG_CPU
314 if (list_empty(&pdev_list)) {
315 err = -ENODEV;
316 goto exit_hp_unreg;
317 }
318#endif
319 return 0;
320
321#ifndef CONFIG_HOTPLUG_CPU
322exit_hp_unreg:
323 cpuhp_remove_state_nocalls(via_temp_online);
324#endif
325exit_driver_unreg:
326 platform_driver_unregister(&via_cputemp_driver);
327exit:
328 return err;
329}
330
331static void __exit via_cputemp_exit(void)
332{
333 cpuhp_remove_state(via_temp_online);
334 platform_driver_unregister(&via_cputemp_driver);
335}
336
337MODULE_AUTHOR("Harald Welte <HaraldWelte@viatech.com>");
338MODULE_DESCRIPTION("VIA CPU temperature monitor");
339MODULE_LICENSE("GPL");
340
341module_init(via_cputemp_init)
342module_exit(via_cputemp_exit)
343