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 #include <linux/module.h>
  25 #include <linux/init.h>
  26 #include <linux/slab.h>
  27 #include <linux/hwmon.h>
  28 #include <linux/sysfs.h>
  29 #include <linux/hwmon-sysfs.h>
  30 #include <linux/err.h>
  31 #include <linux/mutex.h>
  32 #include <linux/list.h>
  33 #include <linux/platform_device.h>
  34 #include <linux/cpu.h>
  35 #include <asm/msr.h>
  36 #include <asm/processor.h>
  37
  38 #define DRVNAME "via_cputemp"
  39
  40 enum { SHOW_TEMP, SHOW_LABEL, SHOW_NAME };
  41
  42 /*
  43  * Functions declaration
  44  */
  45
  46 struct via_cputemp_data {
  47         struct device *hwmon_dev;
  48         const char *name;
  49         u32 id;
  50         u32 msr;
  51 };
  52
  53 /*
  54  * Sysfs stuff
  55  */
  56
  57 static ssize_t show_name(struct device *dev, struct device_attribute
  58                           *devattr, char *buf)
  59 {
  60         int ret;
  61         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
  62         struct via_cputemp_data *data = dev_get_drvdata(dev);
  63
  64         if (attr->index == SHOW_NAME)
  65                 ret = sprintf(buf, "%s\n", data->name);
  66         else    /* show label */
  67                 ret = sprintf(buf, "Core %d\n", data->id);
  68         return ret;
  69 }
  70
  71 static ssize_t show_temp(struct device *dev,
  72                          struct device_attribute *devattr, char *buf)
  73 {
  74         struct via_cputemp_data *data = dev_get_drvdata(dev);
  75         u32 eax, edx;
  76         int err;
  77
  78         err = rdmsr_safe_on_cpu(data->id, data->msr, &eax, &edx);
  79         if (err)
  80                 return -EAGAIN;
  81
  82         return sprintf(buf, "%lu\n", ((unsigned long)eax & 0xffffff) * 1000);
  83 }
  84
  85 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL,
  86                           SHOW_TEMP);
  87 static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, show_name, NULL, SHOW_LABEL);
  88 static SENSOR_DEVICE_ATTR(name, S_IRUGO, show_name, NULL, SHOW_NAME);
  89
  90 static struct attribute *via_cputemp_attributes[] = {
  91         &sensor_dev_attr_name.dev_attr.attr,
  92         &sensor_dev_attr_temp1_label.dev_attr.attr,
  93         &sensor_dev_attr_temp1_input.dev_attr.attr,
  94         NULL
  95 };
  96
  97 static const struct attribute_group via_cputemp_group = {
  98         .attrs = via_cputemp_attributes,
  99 };
 100
 101 static int __devinit via_cputemp_probe(struct platform_device *pdev)
 102 {
 103         struct via_cputemp_data *data;
 104         struct cpuinfo_x86 *c = &cpu_data(pdev->id);
 105         int err;
 106         u32 eax, edx;
 107
 108         data = kzalloc(sizeof(struct via_cputemp_data), GFP_KERNEL);
 109         if (!data) {
 110                 err = -ENOMEM;
 111                 dev_err(&pdev->dev, "Out of memory\n");
 112                 goto exit;
 113         }
 114
 115         data->id = pdev->id;
 116         data->name = "via_cputemp";
 117
 118         switch (c->x86_model) {
 119         case 0xA:
 120                 /* C7 A */
 121         case 0xD:
 122                 /* C7 D */
 123                 data->msr = 0x1169;
 124                 break;
 125         case 0xF:
 126                 /* Nano */
 127                 data->msr = 0x1423;
 128                 break;
 129         default:
 130                 err = -ENODEV;
 131                 goto exit_free;
 132         }
 133
 134         /* test if we can access the TEMPERATURE MSR */
 135         err = rdmsr_safe_on_cpu(data->id, data->msr, &eax, &edx);
 136         if (err) {
 137                 dev_err(&pdev->dev,
 138                         "Unable to access TEMPERATURE MSR, giving up\n");
 139                 goto exit_free;
 140         }
 141
 142         platform_set_drvdata(pdev, data);
 143
 144         err = sysfs_create_group(&pdev->dev.kobj, &via_cputemp_group);
 145         if (err)
 146                 goto exit_free;
 147
 148         data->hwmon_dev = hwmon_device_register(&pdev->dev);
 149         if (IS_ERR(data->hwmon_dev)) {
 150                 err = PTR_ERR(data->hwmon_dev);
 151                 dev_err(&pdev->dev, "Class registration failed (%d)\n",
 152                         err);
 153                 goto exit_remove;
 154         }
 155
 156         return 0;
 157
 158 exit_remove:
 159         sysfs_remove_group(&pdev->dev.kobj, &via_cputemp_group);
 160 exit_free:
 161         platform_set_drvdata(pdev, NULL);
 162         kfree(data);
 163 exit:
 164         return err;
 165 }
 166
 167 static int __devexit via_cputemp_remove(struct platform_device *pdev)
 168 {
 169         struct via_cputemp_data *data = platform_get_drvdata(pdev);
 170
 171         hwmon_device_unregister(data->hwmon_dev);
 172         sysfs_remove_group(&pdev->dev.kobj, &via_cputemp_group);
 173         platform_set_drvdata(pdev, NULL);
 174         kfree(data);
 175         return 0;
 176 }
 177
 178 static struct platform_driver via_cputemp_driver = {
 179         .driver = {
 180                 .owner = THIS_MODULE,
 181                 .name = DRVNAME,
 182         },
 183         .probe = via_cputemp_probe,
 184         .remove = __devexit_p(via_cputemp_remove),
 185 };
 186
 187 struct pdev_entry {
 188         struct list_head list;
 189         struct platform_device *pdev;
 190         unsigned int cpu;
 191 };
 192
 193 static LIST_HEAD(pdev_list);
 194 static DEFINE_MUTEX(pdev_list_mutex);
 195
 196 static int __cpuinit via_cputemp_device_add(unsigned int cpu)
 197 {
 198         int err;
 199         struct platform_device *pdev;
 200         struct pdev_entry *pdev_entry;
 201
 202         pdev = platform_device_alloc(DRVNAME, cpu);
 203         if (!pdev) {
 204                 err = -ENOMEM;
 205                 printk(KERN_ERR DRVNAME ": Device allocation failed\n");
 206                 goto exit;
 207         }
 208
 209         pdev_entry = kzalloc(sizeof(struct pdev_entry), GFP_KERNEL);
 210         if (!pdev_entry) {
 211                 err = -ENOMEM;
 212                 goto exit_device_put;
 213         }
 214
 215         err = platform_device_add(pdev);
 216         if (err) {
 217                 printk(KERN_ERR DRVNAME ": Device addition failed (%d)\n",
 218                        err);
 219                 goto exit_device_free;
 220         }
 221
 222         pdev_entry->pdev = pdev;
 223         pdev_entry->cpu = cpu;
 224         mutex_lock(&pdev_list_mutex);
 225         list_add_tail(&pdev_entry->list, &pdev_list);
 226         mutex_unlock(&pdev_list_mutex);
 227
 228         return 0;
 229
 230 exit_device_free:
 231         kfree(pdev_entry);
 232 exit_device_put:
 233         platform_device_put(pdev);
 234 exit:
 235         return err;
 236 }
 237
 238 static void __cpuinit via_cputemp_device_remove(unsigned int cpu)
 239 {
 240         struct pdev_entry *p, *n;
 241         mutex_lock(&pdev_list_mutex);
 242         list_for_each_entry_safe(p, n, &pdev_list, list) {
 243                 if (p->cpu == cpu) {
 244                         platform_device_unregister(p->pdev);
 245                         list_del(&p->list);
 246                         kfree(p);
 247                 }
 248         }
 249         mutex_unlock(&pdev_list_mutex);
 250 }
 251
 252 static int __cpuinit via_cputemp_cpu_callback(struct notifier_block *nfb,
 253                                  unsigned long action, void *hcpu)
 254 {
 255         unsigned int cpu = (unsigned long) hcpu;
 256
 257         switch (action) {
 258         case CPU_ONLINE:
 259         case CPU_DOWN_FAILED:
 260                 via_cputemp_device_add(cpu);
 261                 break;
 262         case CPU_DOWN_PREPARE:
 263                 via_cputemp_device_remove(cpu);
 264                 break;
 265         }
 266         return NOTIFY_OK;
 267 }
 268
 269 static struct notifier_block via_cputemp_cpu_notifier __refdata = {
 270         .notifier_call = via_cputemp_cpu_callback,
 271 };
 272
 273 static int __init via_cputemp_init(void)
 274 {
 275         int i, err;
 276         struct pdev_entry *p, *n;
 277
 278         if (cpu_data(0).x86_vendor != X86_VENDOR_CENTAUR) {
 279                 printk(KERN_DEBUG DRVNAME ": Not a VIA CPU\n");
 280                 err = -ENODEV;
 281                 goto exit;
 282         }
 283
 284         err = platform_driver_register(&via_cputemp_driver);
 285         if (err)
 286                 goto exit;
 287
 288         for_each_online_cpu(i) {
 289                 struct cpuinfo_x86 *c = &cpu_data(i);
 290
 291                 if (c->x86 != 6)
 292                         continue;
 293
 294                 if (c->x86_model < 0x0a)
 295                         continue;
 296
 297                 if (c->x86_model > 0x0f) {
 298                         printk(KERN_WARNING DRVNAME ": Unknown CPU "
 299                                 "model 0x%x\n", c->x86_model);
 300                         continue;
 301                 }
 302
 303                 err = via_cputemp_device_add(i);
 304                 if (err)
 305                         goto exit_devices_unreg;
 306         }
 307         if (list_empty(&pdev_list)) {
 308                 err = -ENODEV;
 309                 goto exit_driver_unreg;
 310         }
 311
 312         register_hotcpu_notifier(&via_cputemp_cpu_notifier);
 313         return 0;
 314
 315 exit_devices_unreg:
 316         mutex_lock(&pdev_list_mutex);
 317         list_for_each_entry_safe(p, n, &pdev_list, list) {
 318                 platform_device_unregister(p->pdev);
 319                 list_del(&p->list);
 320                 kfree(p);
 321         }
 322         mutex_unlock(&pdev_list_mutex);
 323 exit_driver_unreg:
 324         platform_driver_unregister(&via_cputemp_driver);
 325 exit:
 326         return err;
 327 }
 328
 329 static void __exit via_cputemp_exit(void)
 330 {
 331         struct pdev_entry *p, *n;
 332
 333         unregister_hotcpu_notifier(&via_cputemp_cpu_notifier);
 334         mutex_lock(&pdev_list_mutex);
 335         list_for_each_entry_safe(p, n, &pdev_list, list) {
 336                 platform_device_unregister(p->pdev);
 337                 list_del(&p->list);
 338                 kfree(p);
 339         }
 340         mutex_unlock(&pdev_list_mutex);
 341         platform_driver_unregister(&via_cputemp_driver);
 342 }
 343
 344 MODULE_AUTHOR("Harald Welte <HaraldWelte@viatech.com>");
 345 MODULE_DESCRIPTION("VIA CPU temperature monitor");
 346 MODULE_LICENSE("GPL");
 347
 348 module_init(via_cputemp_init)
 349 module_exit(via_cputemp_exit)