drivers/hwmon/coretemp.c

   1 /*
   2  * coretemp.c - Linux kernel module for hardware monitoring
   3  *
   4  * Copyright (C) 2007 Rudolf Marek <r.marek@assembler.cz>
   5  *
   6  * Inspired from many hwmon drivers
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; version 2 of the License.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  20  * 02110-1301 USA.
  21  */
  22
  23 #include <linux/module.h>
  24 #include <linux/delay.h>
  25 #include <linux/init.h>
  26 #include <linux/slab.h>
  27 #include <linux/jiffies.h>
  28 #include <linux/hwmon.h>
  29 #include <linux/sysfs.h>
  30 #include <linux/hwmon-sysfs.h>
  31 #include <linux/err.h>
  32 #include <linux/mutex.h>
  33 #include <linux/list.h>
  34 #include <linux/platform_device.h>
  35 #include <linux/cpu.h>
  36 #include <asm/msr.h>
  37 #include <asm/processor.h>
  38
  39 #define DRVNAME "coretemp"
  40
  41 typedef enum { SHOW_TEMP, SHOW_TJMAX, SHOW_LABEL, SHOW_NAME } SHOW;
  42
  43 /*
  44  * Functions declaration
  45  */
  46
  47 static struct coretemp_data *coretemp_update_device(struct device *dev);
  48
  49 struct coretemp_data {
  50         struct class_device *class_dev;
  51         struct mutex update_lock;
  52         const char *name;
  53         u32 id;
  54         char valid;             /* zero until following fields are valid */
  55         unsigned long last_updated;     /* in jiffies */
  56         int temp;
  57         int tjmax;
  58         u8 alarm;
  59 };
  60
  61 static struct coretemp_data *coretemp_update_device(struct device *dev);
  62
  63 /*
  64  * Sysfs stuff
  65  */
  66
  67 static ssize_t show_name(struct device *dev, struct device_attribute
  68                           *devattr, char *buf)
  69 {
  70         int ret;
  71         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
  72         struct coretemp_data *data = dev_get_drvdata(dev);
  73
  74         if (attr->index == SHOW_NAME)
  75                 ret = sprintf(buf, "%s\n", data->name);
  76         else    /* show label */
  77                 ret = sprintf(buf, "Core %d\n", data->id);
  78         return ret;
  79 }
  80
  81 static ssize_t show_alarm(struct device *dev, struct device_attribute
  82                           *devattr, char *buf)
  83 {
  84         struct coretemp_data *data = coretemp_update_device(dev);
  85         /* read the Out-of-spec log, never clear */
  86         return sprintf(buf, "%d\n", data->alarm);
  87 }
  88
  89 static ssize_t show_temp(struct device *dev,
  90                          struct device_attribute *devattr, char *buf)
  91 {
  92         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
  93         struct coretemp_data *data = coretemp_update_device(dev);
  94         int err;
  95
  96         if (attr->index == SHOW_TEMP)
  97                 err = data->valid ? sprintf(buf, "%d\n", data->temp) : -EAGAIN;
  98         else
  99                 err = sprintf(buf, "%d\n", data->tjmax);
 100
 101         return err;
 102 }
 103
 104 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL,
 105                           SHOW_TEMP);
 106 static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO, show_temp, NULL,
 107                           SHOW_TJMAX);
 108 static DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL);
 109 static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, show_name, NULL, SHOW_LABEL);
 110 static SENSOR_DEVICE_ATTR(name, S_IRUGO, show_name, NULL, SHOW_NAME);
 111
 112 static struct attribute *coretemp_attributes[] = {
 113         &sensor_dev_attr_name.dev_attr.attr,
 114         &sensor_dev_attr_temp1_label.dev_attr.attr,
 115         &dev_attr_temp1_crit_alarm.attr,
 116         &sensor_dev_attr_temp1_input.dev_attr.attr,
 117         &sensor_dev_attr_temp1_crit.dev_attr.attr,
 118         NULL
 119 };
 120
 121 static const struct attribute_group coretemp_group = {
 122         .attrs = coretemp_attributes,
 123 };
 124
 125 static struct coretemp_data *coretemp_update_device(struct device *dev)
 126 {
 127         struct coretemp_data *data = dev_get_drvdata(dev);
 128
 129         mutex_lock(&data->update_lock);
 130
 131         if (!data->valid || time_after(jiffies, data->last_updated + HZ)) {
 132                 u32 eax, edx;
 133
 134                 data->valid = 0;
 135                 rdmsr_on_cpu(data->id, MSR_IA32_THERM_STATUS, &eax, &edx);
 136                 data->alarm = (eax >> 5) & 1;
 137                 /* update only if data has been valid */
 138                 if (eax & 0x80000000) {
 139                         data->temp = data->tjmax - (((eax >> 16)
 140                                                         & 0x7f) * 1000);
 141                         data->valid = 1;
 142                 } else {
 143                         dev_dbg(dev, "Temperature data invalid (0x%x)\n", eax);
 144                 }
 145                 data->last_updated = jiffies;
 146         }
 147
 148         mutex_unlock(&data->update_lock);
 149         return data;
 150 }
 151
 152 static int __devinit coretemp_probe(struct platform_device *pdev)
 153 {
 154         struct coretemp_data *data;
 155         struct cpuinfo_x86 *c = &(cpu_data)[pdev->id];
 156         int err;
 157         u32 eax, edx;
 158
 159         if (!(data = kzalloc(sizeof(struct coretemp_data), GFP_KERNEL))) {
 160                 err = -ENOMEM;
 161                 dev_err(&pdev->dev, "Out of memory\n");
 162                 goto exit;
 163         }
 164
 165         data->id = pdev->id;
 166         data->name = "coretemp";
 167         mutex_init(&data->update_lock);
 168         /* Tjmax default is 100 degrees C */
 169         data->tjmax = 100000;
 170
 171         /* test if we can access the THERM_STATUS MSR */
 172         err = rdmsr_safe_on_cpu(data->id, MSR_IA32_THERM_STATUS, &eax, &edx);
 173         if (err) {
 174                 dev_err(&pdev->dev,
 175                         "Unable to access THERM_STATUS MSR, giving up\n");
 176                 goto exit_free;
 177         }
 178
 179         /* Some processors have Tjmax 85 following magic should detect it
 180            Intel won't disclose the information without signed NDA, but
 181            individuals cannot sign it. Catch(ed) 22.
 182         */
 183
 184         if (((c->x86_model == 0xf) && (c->x86_mask > 3)) ||
 185                 (c->x86_model == 0xe))  {
 186                 err = rdmsr_safe_on_cpu(data->id, 0xee, &eax, &edx);
 187                 if (err) {
 188                         dev_warn(&pdev->dev,
 189                                  "Unable to access MSR 0xEE, Tjmax left at %d "
 190                                  "degrees C\n", data->tjmax/1000);
 191                 } else if (eax & 0x40000000) {
 192                         data->tjmax = 85000;
 193                 }
 194         }
 195
 196         platform_set_drvdata(pdev, data);
 197
 198         if ((err = sysfs_create_group(&pdev->dev.kobj, &coretemp_group)))
 199                 goto exit_free;
 200
 201         data->class_dev = hwmon_device_register(&pdev->dev);
 202         if (IS_ERR(data->class_dev)) {
 203                 err = PTR_ERR(data->class_dev);
 204                 dev_err(&pdev->dev, "Class registration failed (%d)\n",
 205                         err);
 206                 goto exit_class;
 207         }
 208
 209         return 0;
 210
 211 exit_class:
 212         sysfs_remove_group(&pdev->dev.kobj, &coretemp_group);
 213 exit_free:
 214         kfree(data);
 215 exit:
 216         return err;
 217 }
 218
 219 static int __devexit coretemp_remove(struct platform_device *pdev)
 220 {
 221         struct coretemp_data *data = platform_get_drvdata(pdev);
 222
 223         hwmon_device_unregister(data->class_dev);
 224         sysfs_remove_group(&pdev->dev.kobj, &coretemp_group);
 225         platform_set_drvdata(pdev, NULL);
 226         kfree(data);
 227         return 0;
 228 }
 229
 230 static struct platform_driver coretemp_driver = {
 231         .driver = {
 232                 .owner = THIS_MODULE,
 233                 .name = DRVNAME,
 234         },
 235         .probe = coretemp_probe,
 236         .remove = __devexit_p(coretemp_remove),
 237 };
 238
 239 struct pdev_entry {
 240         struct list_head list;
 241         struct platform_device *pdev;
 242         unsigned int cpu;
 243 };
 244
 245 static LIST_HEAD(pdev_list);
 246 static DEFINE_MUTEX(pdev_list_mutex);
 247
 248 static int __cpuinit coretemp_device_add(unsigned int cpu)
 249 {
 250         int err;
 251         struct platform_device *pdev;
 252         struct pdev_entry *pdev_entry;
 253
 254         pdev = platform_device_alloc(DRVNAME, cpu);
 255         if (!pdev) {
 256                 err = -ENOMEM;
 257                 printk(KERN_ERR DRVNAME ": Device allocation failed\n");
 258                 goto exit;
 259         }
 260
 261         pdev_entry = kzalloc(sizeof(struct pdev_entry), GFP_KERNEL);
 262         if (!pdev_entry) {
 263                 err = -ENOMEM;
 264                 goto exit_device_put;
 265         }
 266
 267         err = platform_device_add(pdev);
 268         if (err) {
 269                 printk(KERN_ERR DRVNAME ": Device addition failed (%d)\n",
 270                        err);
 271                 goto exit_device_free;
 272         }
 273
 274         pdev_entry->pdev = pdev;
 275         pdev_entry->cpu = cpu;
 276         mutex_lock(&pdev_list_mutex);
 277         list_add_tail(&pdev_entry->list, &pdev_list);
 278         mutex_unlock(&pdev_list_mutex);
 279
 280         return 0;
 281
 282 exit_device_free:
 283         kfree(pdev_entry);
 284 exit_device_put:
 285         platform_device_put(pdev);
 286 exit:
 287         return err;
 288 }
 289
 290 #ifdef CONFIG_HOTPLUG_CPU
 291 void coretemp_device_remove(unsigned int cpu)
 292 {
 293         struct pdev_entry *p, *n;
 294         mutex_lock(&pdev_list_mutex);
 295         list_for_each_entry_safe(p, n, &pdev_list, list) {
 296                 if (p->cpu == cpu) {
 297                         platform_device_unregister(p->pdev);
 298                         list_del(&p->list);
 299                         kfree(p);
 300                 }
 301         }
 302         mutex_unlock(&pdev_list_mutex);
 303 }
 304
 305 static int coretemp_cpu_callback(struct notifier_block *nfb,
 306                                  unsigned long action, void *hcpu)
 307 {
 308         unsigned int cpu = (unsigned long) hcpu;
 309
 310         switch (action) {
 311         case CPU_ONLINE:
 312                 coretemp_device_add(cpu);
 313                 break;
 314         case CPU_DEAD:
 315                 coretemp_device_remove(cpu);
 316                 break;
 317         }
 318         return NOTIFY_OK;
 319 }
 320
 321 static struct notifier_block __cpuinitdata coretemp_cpu_notifier = {
 322         .notifier_call = coretemp_cpu_callback,
 323 };
 324 #endif                          /* !CONFIG_HOTPLUG_CPU */
 325
 326 static int __init coretemp_init(void)
 327 {
 328         int i, err = -ENODEV;
 329         struct pdev_entry *p, *n;
 330
 331         printk(KERN_NOTICE DRVNAME ": This driver uses undocumented features "
 332                 "of Core CPU. Temperature might be wrong!\n");
 333
 334         /* quick check if we run Intel */
 335         if (cpu_data[0].x86_vendor != X86_VENDOR_INTEL)
 336                 goto exit;
 337
 338         err = platform_driver_register(&coretemp_driver);
 339         if (err)
 340                 goto exit;
 341
 342         for_each_online_cpu(i) {
 343                 struct cpuinfo_x86 *c = &(cpu_data)[i];
 344
 345                 /* check if family 6, models e, f */
 346                 if ((c->cpuid_level < 0) || (c->x86 != 0x6) ||
 347                     !((c->x86_model == 0xe) || (c->x86_model == 0xf))) {
 348
 349                         /* supported CPU not found, but report the unknown
 350                            family 6 CPU */
 351                         if ((c->x86 == 0x6) && (c->x86_model > 0xf))
 352                                 printk(KERN_WARNING DRVNAME ": Unknown CPU "
 353                                         "model %x\n", c->x86_model);
 354                         continue;
 355                 }
 356
 357                 err = coretemp_device_add(i);
 358                 if (err)
 359                         goto exit_devices_unreg;
 360         }
 361         if (list_empty(&pdev_list)) {
 362                 err = -ENODEV;
 363                 goto exit_driver_unreg;
 364         }
 365
 366 #ifdef CONFIG_HOTPLUG_CPU
 367         register_hotcpu_notifier(&coretemp_cpu_notifier);
 368 #endif
 369         return 0;
 370
 371 exit_devices_unreg:
 372         mutex_lock(&pdev_list_mutex);
 373         list_for_each_entry_safe(p, n, &pdev_list, list) {
 374                 platform_device_unregister(p->pdev);
 375                 list_del(&p->list);
 376                 kfree(p);
 377         }
 378         mutex_unlock(&pdev_list_mutex);
 379 exit_driver_unreg:
 380         platform_driver_unregister(&coretemp_driver);
 381 exit:
 382         return err;
 383 }
 384
 385 static void __exit coretemp_exit(void)
 386 {
 387         struct pdev_entry *p, *n;
 388 #ifdef CONFIG_HOTPLUG_CPU
 389         unregister_hotcpu_notifier(&coretemp_cpu_notifier);
 390 #endif
 391         mutex_lock(&pdev_list_mutex);
 392         list_for_each_entry_safe(p, n, &pdev_list, list) {
 393                 platform_device_unregister(p->pdev);
 394                 list_del(&p->list);
 395                 kfree(p);
 396         }
 397         mutex_unlock(&pdev_list_mutex);
 398         platform_driver_unregister(&coretemp_driver);
 399 }
 400
 401 MODULE_AUTHOR("Rudolf Marek <r.marek@assembler.cz>");
 402 MODULE_DESCRIPTION("Intel Core temperature monitor");
 403 MODULE_LICENSE("GPL");
 404
 405 module_init(coretemp_init)
 406 module_exit(coretemp_exit)