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