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/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>
38 #include <asm/processor.h>
40 #define DRVNAME "via_cputemp"
42 enum { SHOW_TEMP, SHOW_LABEL, SHOW_NAME };
45 * Functions declaration
48 struct via_cputemp_data {
49 struct device *hwmon_dev;
59 static ssize_t show_name(struct device *dev, struct device_attribute
63 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
64 struct via_cputemp_data *data = dev_get_drvdata(dev);
66 if (attr->index == SHOW_NAME)
67 ret = sprintf(buf, "%s\n", data->name);
69 ret = sprintf(buf, "Core %d\n", data->id);
73 static ssize_t show_temp(struct device *dev,
74 struct device_attribute *devattr, char *buf)
76 struct via_cputemp_data *data = dev_get_drvdata(dev);
80 err = rdmsr_safe_on_cpu(data->id, data->msr, &eax, &edx);
84 return sprintf(buf, "%lu\n", ((unsigned long)eax & 0xffffff) * 1000);
87 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL,
89 static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, show_name, NULL, SHOW_LABEL);
90 static SENSOR_DEVICE_ATTR(name, S_IRUGO, show_name, NULL, SHOW_NAME);
92 static 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,
99 static const struct attribute_group via_cputemp_group = {
100 .attrs = via_cputemp_attributes,
103 static int __devinit via_cputemp_probe(struct platform_device *pdev)
105 struct via_cputemp_data *data;
106 struct cpuinfo_x86 *c = &cpu_data(pdev->id);
110 data = kzalloc(sizeof(struct via_cputemp_data), GFP_KERNEL);
113 dev_err(&pdev->dev, "Out of memory\n");
118 data->name = "via_cputemp";
120 switch (c->x86_model) {
136 /* test if we can access the TEMPERATURE MSR */
137 err = rdmsr_safe_on_cpu(data->id, data->msr, &eax, &edx);
140 "Unable to access TEMPERATURE MSR, giving up\n");
144 platform_set_drvdata(pdev, data);
146 err = sysfs_create_group(&pdev->dev.kobj, &via_cputemp_group);
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",
161 sysfs_remove_group(&pdev->dev.kobj, &via_cputemp_group);
163 platform_set_drvdata(pdev, NULL);
169 static int __devexit via_cputemp_remove(struct platform_device *pdev)
171 struct via_cputemp_data *data = platform_get_drvdata(pdev);
173 hwmon_device_unregister(data->hwmon_dev);
174 sysfs_remove_group(&pdev->dev.kobj, &via_cputemp_group);
175 platform_set_drvdata(pdev, NULL);
180 static struct platform_driver via_cputemp_driver = {
182 .owner = THIS_MODULE,
185 .probe = via_cputemp_probe,
186 .remove = __devexit_p(via_cputemp_remove),
190 struct list_head list;
191 struct platform_device *pdev;
195 static LIST_HEAD(pdev_list);
196 static DEFINE_MUTEX(pdev_list_mutex);
198 static int __cpuinit via_cputemp_device_add(unsigned int cpu)
201 struct platform_device *pdev;
202 struct pdev_entry *pdev_entry;
204 pdev = platform_device_alloc(DRVNAME, cpu);
207 pr_err("Device allocation failed\n");
211 pdev_entry = kzalloc(sizeof(struct pdev_entry), GFP_KERNEL);
214 goto exit_device_put;
217 err = platform_device_add(pdev);
219 pr_err("Device addition failed (%d)\n", err);
220 goto exit_device_free;
223 pdev_entry->pdev = pdev;
224 pdev_entry->cpu = cpu;
225 mutex_lock(&pdev_list_mutex);
226 list_add_tail(&pdev_entry->list, &pdev_list);
227 mutex_unlock(&pdev_list_mutex);
234 platform_device_put(pdev);
239 static void __cpuinit via_cputemp_device_remove(unsigned int cpu)
241 struct pdev_entry *p;
243 mutex_lock(&pdev_list_mutex);
244 list_for_each_entry(p, &pdev_list, list) {
246 platform_device_unregister(p->pdev);
248 mutex_unlock(&pdev_list_mutex);
253 mutex_unlock(&pdev_list_mutex);
256 static int __cpuinit via_cputemp_cpu_callback(struct notifier_block *nfb,
257 unsigned long action, void *hcpu)
259 unsigned int cpu = (unsigned long) hcpu;
263 case CPU_DOWN_FAILED:
264 via_cputemp_device_add(cpu);
266 case CPU_DOWN_PREPARE:
267 via_cputemp_device_remove(cpu);
273 static struct notifier_block via_cputemp_cpu_notifier __refdata = {
274 .notifier_call = via_cputemp_cpu_callback,
277 static int __init via_cputemp_init(void)
281 if (cpu_data(0).x86_vendor != X86_VENDOR_CENTAUR) {
282 printk(KERN_DEBUG DRVNAME ": Not a VIA CPU\n");
287 err = platform_driver_register(&via_cputemp_driver);
291 for_each_online_cpu(i) {
292 struct cpuinfo_x86 *c = &cpu_data(i);
297 if (c->x86_model < 0x0a)
300 if (c->x86_model > 0x0f) {
301 pr_warn("Unknown CPU model 0x%x\n", c->x86_model);
305 via_cputemp_device_add(i);
308 #ifndef CONFIG_HOTPLUG_CPU
309 if (list_empty(&pdev_list)) {
311 goto exit_driver_unreg;
315 register_hotcpu_notifier(&via_cputemp_cpu_notifier);
318 #ifndef CONFIG_HOTPLUG_CPU
320 platform_driver_unregister(&via_cputemp_driver);
326 static void __exit via_cputemp_exit(void)
328 struct pdev_entry *p, *n;
330 unregister_hotcpu_notifier(&via_cputemp_cpu_notifier);
331 mutex_lock(&pdev_list_mutex);
332 list_for_each_entry_safe(p, n, &pdev_list, list) {
333 platform_device_unregister(p->pdev);
337 mutex_unlock(&pdev_list_mutex);
338 platform_driver_unregister(&via_cputemp_driver);
341 MODULE_AUTHOR("Harald Welte <HaraldWelte@viatech.com>");
342 MODULE_DESCRIPTION("VIA CPU temperature monitor");
343 MODULE_LICENSE("GPL");
345 module_init(via_cputemp_init)
346 module_exit(via_cputemp_exit)