drivers/hwmon/via-cputemp.c

   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
  41 #define DRVNAME "via_cputemp"
  42
  43 enum { SHOW_TEMP, SHOW_LABEL, SHOW_NAME };
  44
  45 /*
  46  * Functions declaration
  47  */
  48
  49 struct via_cputemp_data {
  50         struct device *hwmon_dev;
  51         const char *name;
  52         u8 vrm;
  53         u32 id;
  54         u32 msr_temp;
  55         u32 msr_vid;
  56 };
  57
  58 /*
  59  * Sysfs stuff
  60  */
  61
  62 static ssize_t show_name(struct device *dev, struct device_attribute
  63                           *devattr, char *buf)
  64 {
  65         int ret;
  66         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
  67         struct via_cputemp_data *data = dev_get_drvdata(dev);
  68
  69         if (attr->index == SHOW_NAME)
  70                 ret = sprintf(buf, "%s\n", data->name);
  71         else    /* show label */
  72                 ret = sprintf(buf, "Core %d\n", data->id);
  73         return ret;
  74 }
  75
  76 static ssize_t show_temp(struct device *dev,
  77                          struct device_attribute *devattr, char *buf)
  78 {
  79         struct via_cputemp_data *data = dev_get_drvdata(dev);
  80         u32 eax, edx;
  81         int err;
  82
  83         err = rdmsr_safe_on_cpu(data->id, data->msr_temp, &eax, &edx);
  84         if (err)
  85                 return -EAGAIN;
  86
  87         return sprintf(buf, "%lu\n", ((unsigned long)eax & 0xffffff) * 1000);
  88 }
  89
  90 static ssize_t show_cpu_vid(struct device *dev,
  91                             struct device_attribute *devattr, char *buf)
  92 {
  93         struct via_cputemp_data *data = dev_get_drvdata(dev);
  94         u32 eax, edx;
  95         int err;
  96
  97         err = rdmsr_safe_on_cpu(data->id, data->msr_vid, &eax, &edx);
  98         if (err)
  99                 return -EAGAIN;
 100
 101         return sprintf(buf, "%d\n", vid_from_reg(~edx & 0x7f, data->vrm));
 102 }
 103
 104 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL,
 105                           SHOW_TEMP);
 106 static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, show_name, NULL, SHOW_LABEL);
 107 static SENSOR_DEVICE_ATTR(name, S_IRUGO, show_name, NULL, SHOW_NAME);
 108
 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,
 113         NULL
 114 };
 115
 116 static const struct attribute_group via_cputemp_group = {
 117         .attrs = via_cputemp_attributes,
 118 };
 119
 120 /* Optional attributes */
 121 static DEVICE_ATTR(cpu0_vid, S_IRUGO, show_cpu_vid, NULL);
 122
 123 static int __devinit 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 = kzalloc(sizeof(struct via_cputemp_data), GFP_KERNEL);
 131         if (!data) {
 132                 err = -ENOMEM;
 133                 dev_err(&pdev->dev, "Out of memory\n");
 134                 goto exit;
 135         }
 136
 137         data->id = pdev->id;
 138         data->name = "via_cputemp";
 139
 140         switch (c->x86_model) {
 141         case 0xA:
 142                 /* C7 A */
 143         case 0xD:
 144                 /* C7 D */
 145                 data->msr_temp = 0x1169;
 146                 data->msr_vid = 0x198;
 147                 break;
 148         case 0xF:
 149                 /* Nano */
 150                 data->msr_temp = 0x1423;
 151                 break;
 152         default:
 153                 err = -ENODEV;
 154                 goto exit_free;
 155         }
 156
 157         /* test if we can access the TEMPERATURE MSR */
 158         err = rdmsr_safe_on_cpu(data->id, data->msr_temp, &eax, &edx);
 159         if (err) {
 160                 dev_err(&pdev->dev,
 161                         "Unable to access TEMPERATURE MSR, giving up\n");
 162                 goto exit_free;
 163         }
 164
 165         platform_set_drvdata(pdev, data);
 166
 167         err = sysfs_create_group(&pdev->dev.kobj, &via_cputemp_group);
 168         if (err)
 169                 goto exit_free;
 170
 171         if (data->msr_vid)
 172                 data->vrm = vid_which_vrm();
 173
 174         if (data->vrm) {
 175                 err = device_create_file(&pdev->dev, &dev_attr_cpu0_vid);
 176                 if (err)
 177                         goto exit_remove;
 178         }
 179
 180         data->hwmon_dev = hwmon_device_register(&pdev->dev);
 181         if (IS_ERR(data->hwmon_dev)) {
 182                 err = PTR_ERR(data->hwmon_dev);
 183                 dev_err(&pdev->dev, "Class registration failed (%d)\n",
 184                         err);
 185                 goto exit_remove;
 186         }
 187
 188         return 0;
 189
 190 exit_remove:
 191         if (data->vrm)
 192                 device_remove_file(&pdev->dev, &dev_attr_cpu0_vid);
 193         sysfs_remove_group(&pdev->dev.kobj, &via_cputemp_group);
 194 exit_free:
 195         platform_set_drvdata(pdev, NULL);
 196         kfree(data);
 197 exit:
 198         return err;
 199 }
 200
 201 static int __devexit via_cputemp_remove(struct platform_device *pdev)
 202 {
 203         struct via_cputemp_data *data = platform_get_drvdata(pdev);
 204
 205         hwmon_device_unregister(data->hwmon_dev);
 206         if (data->vrm)
 207                 device_remove_file(&pdev->dev, &dev_attr_cpu0_vid);
 208         sysfs_remove_group(&pdev->dev.kobj, &via_cputemp_group);
 209         platform_set_drvdata(pdev, NULL);
 210         kfree(data);
 211         return 0;
 212 }
 213
 214 static struct platform_driver via_cputemp_driver = {
 215         .driver = {
 216                 .owner = THIS_MODULE,
 217                 .name = DRVNAME,
 218         },
 219         .probe = via_cputemp_probe,
 220         .remove = __devexit_p(via_cputemp_remove),
 221 };
 222
 223 struct pdev_entry {
 224         struct list_head list;
 225         struct platform_device *pdev;
 226         unsigned int cpu;
 227 };
 228
 229 static LIST_HEAD(pdev_list);
 230 static DEFINE_MUTEX(pdev_list_mutex);
 231
 232 static int __cpuinit via_cputemp_device_add(unsigned int cpu)
 233 {
 234         int err;
 235         struct platform_device *pdev;
 236         struct pdev_entry *pdev_entry;
 237
 238         pdev = platform_device_alloc(DRVNAME, cpu);
 239         if (!pdev) {
 240                 err = -ENOMEM;
 241                 pr_err("Device allocation failed\n");
 242                 goto exit;
 243         }
 244
 245         pdev_entry = kzalloc(sizeof(struct pdev_entry), GFP_KERNEL);
 246         if (!pdev_entry) {
 247                 err = -ENOMEM;
 248                 goto exit_device_put;
 249         }
 250
 251         err = platform_device_add(pdev);
 252         if (err) {
 253                 pr_err("Device addition failed (%d)\n", err);
 254                 goto exit_device_free;
 255         }
 256
 257         pdev_entry->pdev = pdev;
 258         pdev_entry->cpu = cpu;
 259         mutex_lock(&pdev_list_mutex);
 260         list_add_tail(&pdev_entry->list, &pdev_list);
 261         mutex_unlock(&pdev_list_mutex);
 262
 263         return 0;
 264
 265 exit_device_free:
 266         kfree(pdev_entry);
 267 exit_device_put:
 268         platform_device_put(pdev);
 269 exit:
 270         return err;
 271 }
 272
 273 static void __cpuinit via_cputemp_device_remove(unsigned int cpu)
 274 {
 275         struct pdev_entry *p;
 276
 277         mutex_lock(&pdev_list_mutex);
 278         list_for_each_entry(p, &pdev_list, list) {
 279                 if (p->cpu == cpu) {
 280                         platform_device_unregister(p->pdev);
 281                         list_del(&p->list);
 282                         mutex_unlock(&pdev_list_mutex);
 283                         kfree(p);
 284                         return;
 285                 }
 286         }
 287         mutex_unlock(&pdev_list_mutex);
 288 }
 289
 290 static int __cpuinit via_cputemp_cpu_callback(struct notifier_block *nfb,
 291                                  unsigned long action, void *hcpu)
 292 {
 293         unsigned int cpu = (unsigned long) hcpu;
 294
 295         switch (action) {
 296         case CPU_ONLINE:
 297         case CPU_DOWN_FAILED:
 298                 via_cputemp_device_add(cpu);
 299                 break;
 300         case CPU_DOWN_PREPARE:
 301                 via_cputemp_device_remove(cpu);
 302                 break;
 303         }
 304         return NOTIFY_OK;
 305 }
 306
 307 static struct notifier_block via_cputemp_cpu_notifier __refdata = {
 308         .notifier_call = via_cputemp_cpu_callback,
 309 };
 310
 311 static int __init via_cputemp_init(void)
 312 {
 313         int i, err;
 314
 315         if (cpu_data(0).x86_vendor != X86_VENDOR_CENTAUR) {
 316                 printk(KERN_DEBUG DRVNAME ": Not a VIA CPU\n");
 317                 err = -ENODEV;
 318                 goto exit;
 319         }
 320
 321         err = platform_driver_register(&via_cputemp_driver);
 322         if (err)
 323                 goto exit;
 324
 325         for_each_online_cpu(i) {
 326                 struct cpuinfo_x86 *c = &cpu_data(i);
 327
 328                 if (c->x86 != 6)
 329                         continue;
 330
 331                 if (c->x86_model < 0x0a)
 332                         continue;
 333
 334                 if (c->x86_model > 0x0f) {
 335                         pr_warn("Unknown CPU model 0x%x\n", c->x86_model);
 336                         continue;
 337                 }
 338
 339                 via_cputemp_device_add(i);
 340         }
 341
 342 #ifndef CONFIG_HOTPLUG_CPU
 343         if (list_empty(&pdev_list)) {
 344                 err = -ENODEV;
 345                 goto exit_driver_unreg;
 346         }
 347 #endif
 348
 349         register_hotcpu_notifier(&via_cputemp_cpu_notifier);
 350         return 0;
 351
 352 #ifndef CONFIG_HOTPLUG_CPU
 353 exit_driver_unreg:
 354         platform_driver_unregister(&via_cputemp_driver);
 355 #endif
 356 exit:
 357         return err;
 358 }
 359
 360 static void __exit via_cputemp_exit(void)
 361 {
 362         struct pdev_entry *p, *n;
 363
 364         unregister_hotcpu_notifier(&via_cputemp_cpu_notifier);
 365         mutex_lock(&pdev_list_mutex);
 366         list_for_each_entry_safe(p, n, &pdev_list, list) {
 367                 platform_device_unregister(p->pdev);
 368                 list_del(&p->list);
 369                 kfree(p);
 370         }
 371         mutex_unlock(&pdev_list_mutex);
 372         platform_driver_unregister(&via_cputemp_driver);
 373 }
 374
 375 MODULE_AUTHOR("Harald Welte <HaraldWelte@viatech.com>");
 376 MODULE_DESCRIPTION("VIA CPU temperature monitor");
 377 MODULE_LICENSE("GPL");
 378
 379 module_init(via_cputemp_init)
 380 module_exit(via_cputemp_exit)