2 * via-cputemp.c - Driver for VIA CPU core temperature monitoring
3 * Copyright (C) 2009 VIA Technologies, Inc.
5 * based on existing coretemp.c, which is
7 * Copyright (C) 2007 Rudolf Marek <r.marek@assembler.cz>
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.
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.
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
24 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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>
39 #include <asm/processor.h>
40 #include <asm/cpu_device_id.h>
42 #define DRVNAME "via_cputemp"
44 enum { SHOW_TEMP, SHOW_LABEL, SHOW_NAME };
47 * Functions declaration
50 struct via_cputemp_data {
51 struct device *hwmon_dev;
63 static ssize_t name_show(struct device *dev, struct device_attribute *devattr,
67 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
68 struct via_cputemp_data *data = dev_get_drvdata(dev);
70 if (attr->index == SHOW_NAME)
71 ret = sprintf(buf, "%s\n", data->name);
73 ret = sprintf(buf, "Core %d\n", data->id);
77 static ssize_t temp_show(struct device *dev, struct device_attribute *devattr,
80 struct via_cputemp_data *data = dev_get_drvdata(dev);
84 err = rdmsr_safe_on_cpu(data->id, data->msr_temp, &eax, &edx);
88 return sprintf(buf, "%lu\n", ((unsigned long)eax & 0xffffff) * 1000);
91 static ssize_t cpu0_vid_show(struct device *dev,
92 struct device_attribute *devattr, char *buf)
94 struct via_cputemp_data *data = dev_get_drvdata(dev);
98 err = rdmsr_safe_on_cpu(data->id, data->msr_vid, &eax, &edx);
102 return sprintf(buf, "%d\n", vid_from_reg(~edx & 0x7f, data->vrm));
105 static SENSOR_DEVICE_ATTR_RO(temp1_input, temp, SHOW_TEMP);
106 static SENSOR_DEVICE_ATTR_RO(temp1_label, name, SHOW_LABEL);
107 static SENSOR_DEVICE_ATTR_RO(name, name, SHOW_NAME);
109 static 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,
116 static const struct attribute_group via_cputemp_group = {
117 .attrs = via_cputemp_attributes,
120 /* Optional attributes */
121 static DEVICE_ATTR_RO(cpu0_vid);
123 static int via_cputemp_probe(struct platform_device *pdev)
125 struct via_cputemp_data *data;
126 struct cpuinfo_x86 *c = &cpu_data(pdev->id);
130 data = devm_kzalloc(&pdev->dev, sizeof(struct via_cputemp_data),
136 data->name = "via_cputemp";
139 data->msr_temp = 0x1423;
141 switch (c->x86_model) {
146 data->msr_temp = 0x1169;
147 data->msr_vid = 0x198;
151 data->msr_temp = 0x1423;
158 /* test if we can access the TEMPERATURE MSR */
159 err = rdmsr_safe_on_cpu(data->id, data->msr_temp, &eax, &edx);
162 "Unable to access TEMPERATURE MSR, giving up\n");
166 platform_set_drvdata(pdev, data);
168 err = sysfs_create_group(&pdev->dev.kobj, &via_cputemp_group);
173 data->vrm = vid_which_vrm();
176 err = device_create_file(&pdev->dev, &dev_attr_cpu0_vid);
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",
193 device_remove_file(&pdev->dev, &dev_attr_cpu0_vid);
194 sysfs_remove_group(&pdev->dev.kobj, &via_cputemp_group);
198 static int via_cputemp_remove(struct platform_device *pdev)
200 struct via_cputemp_data *data = platform_get_drvdata(pdev);
202 hwmon_device_unregister(data->hwmon_dev);
204 device_remove_file(&pdev->dev, &dev_attr_cpu0_vid);
205 sysfs_remove_group(&pdev->dev.kobj, &via_cputemp_group);
209 static struct platform_driver via_cputemp_driver = {
213 .probe = via_cputemp_probe,
214 .remove = via_cputemp_remove,
218 struct list_head list;
219 struct platform_device *pdev;
223 static LIST_HEAD(pdev_list);
224 static DEFINE_MUTEX(pdev_list_mutex);
226 static int via_cputemp_online(unsigned int cpu)
229 struct platform_device *pdev;
230 struct pdev_entry *pdev_entry;
232 pdev = platform_device_alloc(DRVNAME, cpu);
235 pr_err("Device allocation failed\n");
239 pdev_entry = kzalloc(sizeof(struct pdev_entry), GFP_KERNEL);
242 goto exit_device_put;
245 err = platform_device_add(pdev);
247 pr_err("Device addition failed (%d)\n", err);
248 goto exit_device_free;
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);
262 platform_device_put(pdev);
267 static int via_cputemp_down_prep(unsigned int cpu)
269 struct pdev_entry *p;
271 mutex_lock(&pdev_list_mutex);
272 list_for_each_entry(p, &pdev_list, list) {
274 platform_device_unregister(p->pdev);
276 mutex_unlock(&pdev_list_mutex);
281 mutex_unlock(&pdev_list_mutex);
285 static 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, },
292 MODULE_DEVICE_TABLE(x86cpu, cputemp_ids);
294 static enum cpuhp_state via_temp_online;
296 static int __init via_cputemp_init(void)
300 if (!x86_match_cpu(cputemp_ids))
303 err = platform_driver_register(&via_cputemp_driver);
307 err = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "hwmon/via:online",
308 via_cputemp_online, via_cputemp_down_prep);
310 goto exit_driver_unreg;
311 via_temp_online = err;
313 #ifndef CONFIG_HOTPLUG_CPU
314 if (list_empty(&pdev_list)) {
321 #ifndef CONFIG_HOTPLUG_CPU
323 cpuhp_remove_state_nocalls(via_temp_online);
326 platform_driver_unregister(&via_cputemp_driver);
331 static void __exit via_cputemp_exit(void)
333 cpuhp_remove_state(via_temp_online);
334 platform_driver_unregister(&via_cputemp_driver);
337 MODULE_AUTHOR("Harald Welte <HaraldWelte@viatech.com>");
338 MODULE_DESCRIPTION("VIA CPU temperature monitor");
339 MODULE_LICENSE("GPL");
341 module_init(via_cputemp_init)
342 module_exit(via_cputemp_exit)