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_TTARGET, SHOW_LABEL,
  42                 SHOW_NAME } SHOW;
  43
  44 /*
  45  * Functions declaration
  46  */
  47
  48 static struct coretemp_data *coretemp_update_device(struct device *dev);
  49
  50 struct coretemp_data {
  51         struct device *hwmon_dev;
  52         struct mutex update_lock;
  53         const char *name;
  54         u32 id;
  55         char valid;             /* zero until following fields are valid */
  56         unsigned long last_updated;     /* in jiffies */
  57         int temp;
  58         int tjmax;
  59         int ttarget;
  60         u8 alarm;
  61 };
  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 if (attr->index == SHOW_TJMAX)
  99                 err = sprintf(buf, "%d\n", data->tjmax);
 100         else
 101                 err = sprintf(buf, "%d\n", data->ttarget);
 102         return err;
 103 }
 104
 105 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL,
 106                           SHOW_TEMP);
 107 static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO, show_temp, NULL,
 108                           SHOW_TJMAX);
 109 static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO, show_temp, NULL,
 110                           SHOW_TTARGET);
 111 static DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL);
 112 static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, show_name, NULL, SHOW_LABEL);
 113 static SENSOR_DEVICE_ATTR(name, S_IRUGO, show_name, NULL, SHOW_NAME);
 114
 115 static struct attribute *coretemp_attributes[] = {
 116         &sensor_dev_attr_name.dev_attr.attr,
 117         &sensor_dev_attr_temp1_label.dev_attr.attr,
 118         &dev_attr_temp1_crit_alarm.attr,
 119         &sensor_dev_attr_temp1_input.dev_attr.attr,
 120         &sensor_dev_attr_temp1_crit.dev_attr.attr,
 121         NULL
 122 };
 123
 124 static const struct attribute_group coretemp_group = {
 125         .attrs = coretemp_attributes,
 126 };
 127
 128 static struct coretemp_data *coretemp_update_device(struct device *dev)
 129 {
 130         struct coretemp_data *data = dev_get_drvdata(dev);
 131
 132         mutex_lock(&data->update_lock);
 133
 134         if (!data->valid || time_after(jiffies, data->last_updated + HZ)) {
 135                 u32 eax, edx;
 136
 137                 data->valid = 0;
 138                 rdmsr_on_cpu(data->id, MSR_IA32_THERM_STATUS, &eax, &edx);
 139                 data->alarm = (eax >> 5) & 1;
 140                 /* update only if data has been valid */
 141                 if (eax & 0x80000000) {
 142                         data->temp = data->tjmax - (((eax >> 16)
 143                                                         & 0x7f) * 1000);
 144                         data->valid = 1;
 145                 } else {
 146                         dev_dbg(dev, "Temperature data invalid (0x%x)\n", eax);
 147                 }
 148                 data->last_updated = jiffies;
 149         }
 150
 151         mutex_unlock(&data->update_lock);
 152         return data;
 153 }
 154
 155 static int __devinit adjust_tjmax(struct cpuinfo_x86 *c, u32 id, struct device *dev)
 156 {
 157         /* The 100C is default for both mobile and non mobile CPUs */
 158
 159         int tjmax = 100000;
 160         int ismobile = 1;
 161         int err;
 162         u32 eax, edx;
 163
 164         /* Early chips have no MSR for TjMax */
 165
 166         if ((c->x86_model == 0xf) && (c->x86_mask < 4)) {
 167                 ismobile = 0;
 168         }
 169
 170         if ((c->x86_model > 0xe) && (ismobile)) {
 171
 172                 /* Now we can detect the mobile CPU using Intel provided table
 173                    http://softwarecommunity.intel.com/Wiki/Mobility/720.htm
 174                    For Core2 cores, check MSR 0x17, bit 28 1 = Mobile CPU
 175                 */
 176
 177                 err = rdmsr_safe_on_cpu(id, 0x17, &eax, &edx);
 178                 if (err) {
 179                         dev_warn(dev,
 180                                  "Unable to access MSR 0x17, assuming desktop"
 181                                  " CPU\n");
 182                         ismobile = 0;
 183                 } else if (!(eax & 0x10000000)) {
 184                         ismobile = 0;
 185                 }
 186         }
 187
 188         if (ismobile) {
 189
 190                 err = rdmsr_safe_on_cpu(id, 0xee, &eax, &edx);
 191                 if (err) {
 192                         dev_warn(dev,
 193                                  "Unable to access MSR 0xEE, for Tjmax, left"
 194                                  " at default");
 195                 } else if (eax & 0x40000000) {
 196                         tjmax = 85000;
 197                 }
 198         } else {
 199                 dev_warn(dev, "Using relative temperature scale!\n");
 200         }
 201
 202         return tjmax;
 203 }
 204
 205 static int __devinit coretemp_probe(struct platform_device *pdev)
 206 {
 207         struct coretemp_data *data;
 208         struct cpuinfo_x86 *c = &cpu_data(pdev->id);
 209         int err;
 210         u32 eax, edx;
 211
 212         if (!(data = kzalloc(sizeof(struct coretemp_data), GFP_KERNEL))) {
 213                 err = -ENOMEM;
 214                 dev_err(&pdev->dev, "Out of memory\n");
 215                 goto exit;
 216         }
 217
 218         data->id = pdev->id;
 219         data->name = "coretemp";
 220         mutex_init(&data->update_lock);
 221
 222         /* test if we can access the THERM_STATUS MSR */
 223         err = rdmsr_safe_on_cpu(data->id, MSR_IA32_THERM_STATUS, &eax, &edx);
 224         if (err) {
 225                 dev_err(&pdev->dev,
 226                         "Unable to access THERM_STATUS MSR, giving up\n");
 227                 goto exit_free;
 228         }
 229
 230         /* Check if we have problem with errata AE18 of Core processors:
 231            Readings might stop update when processor visited too deep sleep,
 232            fixed for stepping D0 (6EC).
 233         */
 234
 235         if ((c->x86_model == 0xe) && (c->x86_mask < 0xc)) {
 236                 /* check for microcode update */
 237                 rdmsr_on_cpu(data->id, MSR_IA32_UCODE_REV, &eax, &edx);
 238                 if (edx < 0x39) {
 239                         err = -ENODEV;
 240                         dev_err(&pdev->dev,
 241                                 "Errata AE18 not fixed, update BIOS or "
 242                                 "microcode of the CPU!\n");
 243                         goto exit_free;
 244                 }
 245         }
 246
 247         data->tjmax = adjust_tjmax(c, data->id, &pdev->dev);
 248         platform_set_drvdata(pdev, data);
 249
 250         /* read the still undocumented IA32_TEMPERATURE_TARGET it exists
 251            on older CPUs but not in this register */
 252
 253         if (c->x86_model > 0xe) {
 254                 err = rdmsr_safe_on_cpu(data->id, 0x1a2, &eax, &edx);
 255                 if (err) {
 256                         dev_warn(&pdev->dev, "Unable to read"
 257                                         " IA32_TEMPERATURE_TARGET MSR\n");
 258                 } else {
 259                         data->ttarget = data->tjmax -
 260                                         (((eax >> 8) & 0xff) * 1000);
 261                         err = device_create_file(&pdev->dev,
 262                                         &sensor_dev_attr_temp1_max.dev_attr);
 263                         if (err)
 264                                 goto exit_free;
 265                 }
 266         }
 267
 268         if ((err = sysfs_create_group(&pdev->dev.kobj, &coretemp_group)))
 269                 goto exit_dev;
 270
 271         data->hwmon_dev = hwmon_device_register(&pdev->dev);
 272         if (IS_ERR(data->hwmon_dev)) {
 273                 err = PTR_ERR(data->hwmon_dev);
 274                 dev_err(&pdev->dev, "Class registration failed (%d)\n",
 275                         err);
 276                 goto exit_class;
 277         }
 278
 279         return 0;
 280
 281 exit_class:
 282         sysfs_remove_group(&pdev->dev.kobj, &coretemp_group);
 283 exit_dev:
 284         device_remove_file(&pdev->dev, &sensor_dev_attr_temp1_max.dev_attr);
 285 exit_free:
 286         kfree(data);
 287 exit:
 288         return err;
 289 }
 290
 291 static int __devexit coretemp_remove(struct platform_device *pdev)
 292 {
 293         struct coretemp_data *data = platform_get_drvdata(pdev);
 294
 295         hwmon_device_unregister(data->hwmon_dev);
 296         sysfs_remove_group(&pdev->dev.kobj, &coretemp_group);
 297         device_remove_file(&pdev->dev, &sensor_dev_attr_temp1_max.dev_attr);
 298         platform_set_drvdata(pdev, NULL);
 299         kfree(data);
 300         return 0;
 301 }
 302
 303 static struct platform_driver coretemp_driver = {
 304         .driver = {
 305                 .owner = THIS_MODULE,
 306                 .name = DRVNAME,
 307         },
 308         .probe = coretemp_probe,
 309         .remove = __devexit_p(coretemp_remove),
 310 };
 311
 312 struct pdev_entry {
 313         struct list_head list;
 314         struct platform_device *pdev;
 315         unsigned int cpu;
 316 };
 317
 318 static LIST_HEAD(pdev_list);
 319 static DEFINE_MUTEX(pdev_list_mutex);
 320
 321 static int __cpuinit coretemp_device_add(unsigned int cpu)
 322 {
 323         int err;
 324         struct platform_device *pdev;
 325         struct pdev_entry *pdev_entry;
 326
 327         pdev = platform_device_alloc(DRVNAME, cpu);
 328         if (!pdev) {
 329                 err = -ENOMEM;
 330                 printk(KERN_ERR DRVNAME ": Device allocation failed\n");
 331                 goto exit;
 332         }
 333
 334         pdev_entry = kzalloc(sizeof(struct pdev_entry), GFP_KERNEL);
 335         if (!pdev_entry) {
 336                 err = -ENOMEM;
 337                 goto exit_device_put;
 338         }
 339
 340         err = platform_device_add(pdev);
 341         if (err) {
 342                 printk(KERN_ERR DRVNAME ": Device addition failed (%d)\n",
 343                        err);
 344                 goto exit_device_free;
 345         }
 346
 347         pdev_entry->pdev = pdev;
 348         pdev_entry->cpu = cpu;
 349         mutex_lock(&pdev_list_mutex);
 350         list_add_tail(&pdev_entry->list, &pdev_list);
 351         mutex_unlock(&pdev_list_mutex);
 352
 353         return 0;
 354
 355 exit_device_free:
 356         kfree(pdev_entry);
 357 exit_device_put:
 358         platform_device_put(pdev);
 359 exit:
 360         return err;
 361 }
 362
 363 #ifdef CONFIG_HOTPLUG_CPU
 364 static void coretemp_device_remove(unsigned int cpu)
 365 {
 366         struct pdev_entry *p, *n;
 367         mutex_lock(&pdev_list_mutex);
 368         list_for_each_entry_safe(p, n, &pdev_list, list) {
 369                 if (p->cpu == cpu) {
 370                         platform_device_unregister(p->pdev);
 371                         list_del(&p->list);
 372                         kfree(p);
 373                 }
 374         }
 375         mutex_unlock(&pdev_list_mutex);
 376 }
 377
 378 static int __cpuinit coretemp_cpu_callback(struct notifier_block *nfb,
 379                                  unsigned long action, void *hcpu)
 380 {
 381         unsigned int cpu = (unsigned long) hcpu;
 382
 383         switch (action) {
 384         case CPU_ONLINE:
 385         case CPU_DOWN_FAILED:
 386                 coretemp_device_add(cpu);
 387                 break;
 388         case CPU_DOWN_PREPARE:
 389                 coretemp_device_remove(cpu);
 390                 break;
 391         }
 392         return NOTIFY_OK;
 393 }
 394
 395 static struct notifier_block coretemp_cpu_notifier __refdata = {
 396         .notifier_call = coretemp_cpu_callback,
 397 };
 398 #endif                          /* !CONFIG_HOTPLUG_CPU */
 399
 400 static int __init coretemp_init(void)
 401 {
 402         int i, err = -ENODEV;
 403         struct pdev_entry *p, *n;
 404
 405         /* quick check if we run Intel */
 406         if (cpu_data(0).x86_vendor != X86_VENDOR_INTEL)
 407                 goto exit;
 408
 409         err = platform_driver_register(&coretemp_driver);
 410         if (err)
 411                 goto exit;
 412
 413         for_each_online_cpu(i) {
 414                 struct cpuinfo_x86 *c = &cpu_data(i);
 415
 416                 /* check if family 6, models 0xe, 0xf, 0x16, 0x17 */
 417                 if ((c->cpuid_level < 0) || (c->x86 != 0x6) ||
 418                     !((c->x86_model == 0xe) || (c->x86_model == 0xf) ||
 419                         (c->x86_model == 0x16) || (c->x86_model == 0x17))) {
 420
 421                         /* supported CPU not found, but report the unknown
 422                            family 6 CPU */
 423                         if ((c->x86 == 0x6) && (c->x86_model > 0xf))
 424                                 printk(KERN_WARNING DRVNAME ": Unknown CPU "
 425                                         "model %x\n", c->x86_model);
 426                         continue;
 427                 }
 428
 429                 err = coretemp_device_add(i);
 430                 if (err)
 431                         goto exit_devices_unreg;
 432         }
 433         if (list_empty(&pdev_list)) {
 434                 err = -ENODEV;
 435                 goto exit_driver_unreg;
 436         }
 437
 438 #ifdef CONFIG_HOTPLUG_CPU
 439         register_hotcpu_notifier(&coretemp_cpu_notifier);
 440 #endif
 441         return 0;
 442
 443 exit_devices_unreg:
 444         mutex_lock(&pdev_list_mutex);
 445         list_for_each_entry_safe(p, n, &pdev_list, list) {
 446                 platform_device_unregister(p->pdev);
 447                 list_del(&p->list);
 448                 kfree(p);
 449         }
 450         mutex_unlock(&pdev_list_mutex);
 451 exit_driver_unreg:
 452         platform_driver_unregister(&coretemp_driver);
 453 exit:
 454         return err;
 455 }
 456
 457 static void __exit coretemp_exit(void)
 458 {
 459         struct pdev_entry *p, *n;
 460 #ifdef CONFIG_HOTPLUG_CPU
 461         unregister_hotcpu_notifier(&coretemp_cpu_notifier);
 462 #endif
 463         mutex_lock(&pdev_list_mutex);
 464         list_for_each_entry_safe(p, n, &pdev_list, list) {
 465                 platform_device_unregister(p->pdev);
 466                 list_del(&p->list);
 467                 kfree(p);
 468         }
 469         mutex_unlock(&pdev_list_mutex);
 470         platform_driver_unregister(&coretemp_driver);
 471 }
 472
 473 MODULE_AUTHOR("Rudolf Marek <r.marek@assembler.cz>");
 474 MODULE_DESCRIPTION("Intel Core temperature monitor");
 475 MODULE_LICENSE("GPL");
 476
 477 module_init(coretemp_init)
 478 module_exit(coretemp_exit)