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/delay.h>
  26 #include <linux/init.h>
  27 #include <linux/slab.h>
  28 #include <linux/jiffies.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 } SHOW;
  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                 printk(KERN_ERR DRVNAME ": 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                 printk(KERN_ERR DRVNAME ": Device addition failed (%d)\n",
 220                        err);
 221                 goto exit_device_free;
 222         }
 223
 224         pdev_entry->pdev = pdev;
 225         pdev_entry->cpu = cpu;
 226         mutex_lock(&pdev_list_mutex);
 227         list_add_tail(&pdev_entry->list, &pdev_list);
 228         mutex_unlock(&pdev_list_mutex);
 229
 230         return 0;
 231
 232 exit_device_free:
 233         kfree(pdev_entry);
 234 exit_device_put:
 235         platform_device_put(pdev);
 236 exit:
 237         return err;
 238 }
 239
 240 #ifdef CONFIG_HOTPLUG_CPU
 241 static void via_cputemp_device_remove(unsigned int cpu)
 242 {
 243         struct pdev_entry *p, *n;
 244         mutex_lock(&pdev_list_mutex);
 245         list_for_each_entry_safe(p, n, &pdev_list, list) {
 246                 if (p->cpu == cpu) {
 247                         platform_device_unregister(p->pdev);
 248                         list_del(&p->list);
 249                         kfree(p);
 250                 }
 251         }
 252         mutex_unlock(&pdev_list_mutex);
 253 }
 254
 255 static int __cpuinit via_cputemp_cpu_callback(struct notifier_block *nfb,
 256                                  unsigned long action, void *hcpu)
 257 {
 258         unsigned int cpu = (unsigned long) hcpu;
 259
 260         switch (action) {
 261         case CPU_ONLINE:
 262         case CPU_DOWN_FAILED:
 263                 via_cputemp_device_add(cpu);
 264                 break;
 265         case CPU_DOWN_PREPARE:
 266                 via_cputemp_device_remove(cpu);
 267                 break;
 268         }
 269         return NOTIFY_OK;
 270 }
 271
 272 static struct notifier_block via_cputemp_cpu_notifier __refdata = {
 273         .notifier_call = via_cputemp_cpu_callback,
 274 };
 275 #endif                          /* !CONFIG_HOTPLUG_CPU */
 276
 277 static int __init via_cputemp_init(void)
 278 {
 279         int i, err;
 280         struct pdev_entry *p, *n;
 281
 282         if (cpu_data(0).x86_vendor != X86_VENDOR_CENTAUR) {
 283                 printk(KERN_DEBUG DRVNAME ": Not a VIA CPU\n");
 284                 err = -ENODEV;
 285                 goto exit;
 286         }
 287
 288         err = platform_driver_register(&via_cputemp_driver);
 289         if (err)
 290                 goto exit;
 291
 292         for_each_online_cpu(i) {
 293                 struct cpuinfo_x86 *c = &cpu_data(i);
 294
 295                 if (c->x86 != 6)
 296                         continue;
 297
 298                 if (c->x86_model < 0x0a)
 299                         continue;
 300
 301                 if (c->x86_model > 0x0f) {
 302                         printk(KERN_WARNING DRVNAME ": Unknown CPU "
 303                                 "model 0x%x\n", c->x86_model);
 304                         continue;
 305                 }
 306
 307                 err = via_cputemp_device_add(i);
 308                 if (err)
 309                         goto exit_devices_unreg;
 310         }
 311         if (list_empty(&pdev_list)) {
 312                 err = -ENODEV;
 313                 goto exit_driver_unreg;
 314         }
 315
 316 #ifdef CONFIG_HOTPLUG_CPU
 317         register_hotcpu_notifier(&via_cputemp_cpu_notifier);
 318 #endif
 319         return 0;
 320
 321 exit_devices_unreg:
 322         mutex_lock(&pdev_list_mutex);
 323         list_for_each_entry_safe(p, n, &pdev_list, list) {
 324                 platform_device_unregister(p->pdev);
 325                 list_del(&p->list);
 326                 kfree(p);
 327         }
 328         mutex_unlock(&pdev_list_mutex);
 329 exit_driver_unreg:
 330         platform_driver_unregister(&via_cputemp_driver);
 331 exit:
 332         return err;
 333 }
 334
 335 static void __exit via_cputemp_exit(void)
 336 {
 337         struct pdev_entry *p, *n;
 338 #ifdef CONFIG_HOTPLUG_CPU
 339         unregister_hotcpu_notifier(&via_cputemp_cpu_notifier);
 340 #endif
 341         mutex_lock(&pdev_list_mutex);
 342         list_for_each_entry_safe(p, n, &pdev_list, list) {
 343                 platform_device_unregister(p->pdev);
 344                 list_del(&p->list);
 345                 kfree(p);
 346         }
 347         mutex_unlock(&pdev_list_mutex);
 348         platform_driver_unregister(&via_cputemp_driver);
 349 }
 350
 351 MODULE_AUTHOR("Harald Welte <HaraldWelte@viatech.com>");
 352 MODULE_DESCRIPTION("VIA CPU temperature monitor");
 353 MODULE_LICENSE("GPL");
 354
 355 module_init(via_cputemp_init)
 356 module_exit(via_cputemp_exit)