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 #include <asm/cpu_device_id.h>
  41
  42 #define DRVNAME "via_cputemp"
  43
  44 enum { SHOW_TEMP, SHOW_LABEL, SHOW_NAME };
  45
  46 /*
  47  * Functions declaration
  48  */
  49
  50 struct via_cputemp_data {
  51         struct device *hwmon_dev;
  52         const char *name;
  53         u8 vrm;
  54         u32 id;
  55         u32 msr_temp;
  56         u32 msr_vid;
  57 };
  58
  59 /*
  60  * Sysfs stuff
  61  */
  62
  63 static ssize_t show_name(struct device *dev, struct device_attribute
  64                           *devattr, char *buf)
  65 {
  66         int ret;
  67         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
  68         struct via_cputemp_data *data = dev_get_drvdata(dev);
  69
  70         if (attr->index == SHOW_NAME)
  71                 ret = sprintf(buf, "%s\n", data->name);
  72         else    /* show label */
  73                 ret = sprintf(buf, "Core %d\n", data->id);
  74         return ret;
  75 }
  76
  77 static ssize_t show_temp(struct device *dev,
  78                          struct device_attribute *devattr, char *buf)
  79 {
  80         struct via_cputemp_data *data = dev_get_drvdata(dev);
  81         u32 eax, edx;
  82         int err;
  83
  84         err = rdmsr_safe_on_cpu(data->id, data->msr_temp, &eax, &edx);
  85         if (err)
  86                 return -EAGAIN;
  87
  88         return sprintf(buf, "%lu\n", ((unsigned long)eax & 0xffffff) * 1000);
  89 }
  90
  91 static ssize_t show_cpu_vid(struct device *dev,
  92                             struct device_attribute *devattr, char *buf)
  93 {
  94         struct via_cputemp_data *data = dev_get_drvdata(dev);
  95         u32 eax, edx;
  96         int err;
  97
  98         err = rdmsr_safe_on_cpu(data->id, data->msr_vid, &eax, &edx);
  99         if (err)
 100                 return -EAGAIN;
 101
 102         return sprintf(buf, "%d\n", vid_from_reg(~edx & 0x7f, data->vrm));
 103 }
 104
 105 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL,
 106                           SHOW_TEMP);
 107 static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, show_name, NULL, SHOW_LABEL);
 108 static SENSOR_DEVICE_ATTR(name, S_IRUGO, show_name, NULL, SHOW_NAME);
 109
 110 static struct attribute *via_cputemp_attributes[] = {
 111         &sensor_dev_attr_name.dev_attr.attr,
 112         &sensor_dev_attr_temp1_label.dev_attr.attr,
 113         &sensor_dev_attr_temp1_input.dev_attr.attr,
 114         NULL
 115 };
 116
 117 static const struct attribute_group via_cputemp_group = {
 118         .attrs = via_cputemp_attributes,
 119 };
 120
 121 /* Optional attributes */
 122 static DEVICE_ATTR(cpu0_vid, S_IRUGO, show_cpu_vid, NULL);
 123
 124 static int __devinit via_cputemp_probe(struct platform_device *pdev)
 125 {
 126         struct via_cputemp_data *data;
 127         struct cpuinfo_x86 *c = &cpu_data(pdev->id);
 128         int err;
 129         u32 eax, edx;
 130
 131         data = kzalloc(sizeof(struct via_cputemp_data), GFP_KERNEL);
 132         if (!data) {
 133                 err = -ENOMEM;
 134                 dev_err(&pdev->dev, "Out of memory\n");
 135                 goto exit;
 136         }
 137
 138         data->id = pdev->id;
 139         data->name = "via_cputemp";
 140
 141         switch (c->x86_model) {
 142         case 0xA:
 143                 /* C7 A */
 144         case 0xD:
 145                 /* C7 D */
 146                 data->msr_temp = 0x1169;
 147                 data->msr_vid = 0x198;
 148                 break;
 149         case 0xF:
 150                 /* Nano */
 151                 data->msr_temp = 0x1423;
 152                 break;
 153         default:
 154                 err = -ENODEV;
 155                 goto exit_free;
 156         }
 157
 158         /* test if we can access the TEMPERATURE MSR */
 159         err = rdmsr_safe_on_cpu(data->id, data->msr_temp, &eax, &edx);
 160         if (err) {
 161                 dev_err(&pdev->dev,
 162                         "Unable to access TEMPERATURE MSR, giving up\n");
 163                 goto exit_free;
 164         }
 165
 166         platform_set_drvdata(pdev, data);
 167
 168         err = sysfs_create_group(&pdev->dev.kobj, &via_cputemp_group);
 169         if (err)
 170                 goto exit_free;
 171
 172         if (data->msr_vid)
 173                 data->vrm = vid_which_vrm();
 174
 175         if (data->vrm) {
 176                 err = device_create_file(&pdev->dev, &dev_attr_cpu0_vid);
 177                 if (err)
 178                         goto exit_remove;
 179         }
 180
 181         data->hwmon_dev = hwmon_device_register(&pdev->dev);
 182         if (IS_ERR(data->hwmon_dev)) {
 183                 err = PTR_ERR(data->hwmon_dev);
 184                 dev_err(&pdev->dev, "Class registration failed (%d)\n",
 185                         err);
 186                 goto exit_remove;
 187         }
 188
 189         return 0;
 190
 191 exit_remove:
 192         if (data->vrm)
 193                 device_remove_file(&pdev->dev, &dev_attr_cpu0_vid);
 194         sysfs_remove_group(&pdev->dev.kobj, &via_cputemp_group);
 195 exit_free:
 196         platform_set_drvdata(pdev, NULL);
 197         kfree(data);
 198 exit:
 199         return err;
 200 }
 201
 202 static int __devexit via_cputemp_remove(struct platform_device *pdev)
 203 {
 204         struct via_cputemp_data *data = platform_get_drvdata(pdev);
 205
 206         hwmon_device_unregister(data->hwmon_dev);
 207         if (data->vrm)
 208                 device_remove_file(&pdev->dev, &dev_attr_cpu0_vid);
 209         sysfs_remove_group(&pdev->dev.kobj, &via_cputemp_group);
 210         platform_set_drvdata(pdev, NULL);
 211         kfree(data);
 212         return 0;
 213 }
 214
 215 static struct platform_driver via_cputemp_driver = {
 216         .driver = {
 217                 .owner = THIS_MODULE,
 218                 .name = DRVNAME,
 219         },
 220         .probe = via_cputemp_probe,
 221         .remove = __devexit_p(via_cputemp_remove),
 222 };
 223
 224 struct pdev_entry {
 225         struct list_head list;
 226         struct platform_device *pdev;
 227         unsigned int cpu;
 228 };
 229
 230 static LIST_HEAD(pdev_list);
 231 static DEFINE_MUTEX(pdev_list_mutex);
 232
 233 static int __cpuinit via_cputemp_device_add(unsigned int cpu)
 234 {
 235         int err;
 236         struct platform_device *pdev;
 237         struct pdev_entry *pdev_entry;
 238
 239         pdev = platform_device_alloc(DRVNAME, cpu);
 240         if (!pdev) {
 241                 err = -ENOMEM;
 242                 pr_err("Device allocation failed\n");
 243                 goto exit;
 244         }
 245
 246         pdev_entry = kzalloc(sizeof(struct pdev_entry), GFP_KERNEL);
 247         if (!pdev_entry) {
 248                 err = -ENOMEM;
 249                 goto exit_device_put;
 250         }
 251
 252         err = platform_device_add(pdev);
 253         if (err) {
 254                 pr_err("Device addition failed (%d)\n", err);
 255                 goto exit_device_free;
 256         }
 257
 258         pdev_entry->pdev = pdev;
 259         pdev_entry->cpu = cpu;
 260         mutex_lock(&pdev_list_mutex);
 261         list_add_tail(&pdev_entry->list, &pdev_list);
 262         mutex_unlock(&pdev_list_mutex);
 263
 264         return 0;
 265
 266 exit_device_free:
 267         kfree(pdev_entry);
 268 exit_device_put:
 269         platform_device_put(pdev);
 270 exit:
 271         return err;
 272 }
 273
 274 static void __cpuinit via_cputemp_device_remove(unsigned int cpu)
 275 {
 276         struct pdev_entry *p;
 277
 278         mutex_lock(&pdev_list_mutex);
 279         list_for_each_entry(p, &pdev_list, list) {
 280                 if (p->cpu == cpu) {
 281                         platform_device_unregister(p->pdev);
 282                         list_del(&p->list);
 283                         mutex_unlock(&pdev_list_mutex);
 284                         kfree(p);
 285                         return;
 286                 }
 287         }
 288         mutex_unlock(&pdev_list_mutex);
 289 }
 290
 291 static int __cpuinit via_cputemp_cpu_callback(struct notifier_block *nfb,
 292                                  unsigned long action, void *hcpu)
 293 {
 294         unsigned int cpu = (unsigned long) hcpu;
 295
 296         switch (action) {
 297         case CPU_ONLINE:
 298         case CPU_DOWN_FAILED:
 299                 via_cputemp_device_add(cpu);
 300                 break;
 301         case CPU_DOWN_PREPARE:
 302                 via_cputemp_device_remove(cpu);
 303                 break;
 304         }
 305         return NOTIFY_OK;
 306 }
 307
 308 static struct notifier_block via_cputemp_cpu_notifier __refdata = {
 309         .notifier_call = via_cputemp_cpu_callback,
 310 };
 311
 312 static const struct x86_cpu_id cputemp_ids[] = {
 313         { X86_VENDOR_CENTAUR, 6, 0xa, }, /* C7 A */
 314         { X86_VENDOR_CENTAUR, 6, 0xd, }, /* C7 D */
 315         { X86_VENDOR_CENTAUR, 6, 0xf, }, /* Nano */
 316         {}
 317 };
 318 MODULE_DEVICE_TABLE(x86cpu, cputemp_ids);
 319
 320 static int __init via_cputemp_init(void)
 321 {
 322         int i, err;
 323
 324         if (!x86_match_cpu(cputemp_ids))
 325                 return -ENODEV;
 326
 327         err = platform_driver_register(&via_cputemp_driver);
 328         if (err)
 329                 goto exit;
 330
 331         for_each_online_cpu(i) {
 332                 struct cpuinfo_x86 *c = &cpu_data(i);
 333
 334                 if (c->x86 != 6)
 335                         continue;
 336
 337                 if (c->x86_model < 0x0a)
 338                         continue;
 339
 340                 if (c->x86_model > 0x0f) {
 341                         pr_warn("Unknown CPU model 0x%x\n", c->x86_model);
 342                         continue;
 343                 }
 344
 345                 via_cputemp_device_add(i);
 346         }
 347
 348 #ifndef CONFIG_HOTPLUG_CPU
 349         if (list_empty(&pdev_list)) {
 350                 err = -ENODEV;
 351                 goto exit_driver_unreg;
 352         }
 353 #endif
 354
 355         register_hotcpu_notifier(&via_cputemp_cpu_notifier);
 356         return 0;
 357
 358 #ifndef CONFIG_HOTPLUG_CPU
 359 exit_driver_unreg:
 360         platform_driver_unregister(&via_cputemp_driver);
 361 #endif
 362 exit:
 363         return err;
 364 }
 365
 366 static void __exit via_cputemp_exit(void)
 367 {
 368         struct pdev_entry *p, *n;
 369
 370         unregister_hotcpu_notifier(&via_cputemp_cpu_notifier);
 371         mutex_lock(&pdev_list_mutex);
 372         list_for_each_entry_safe(p, n, &pdev_list, list) {
 373                 platform_device_unregister(p->pdev);
 374                 list_del(&p->list);
 375                 kfree(p);
 376         }
 377         mutex_unlock(&pdev_list_mutex);
 378         platform_driver_unregister(&via_cputemp_driver);
 379 }
 380
 381 MODULE_AUTHOR("Harald Welte <HaraldWelte@viatech.com>");
 382 MODULE_DESCRIPTION("VIA CPU temperature monitor");
 383 MODULE_LICENSE("GPL");
 384
 385 module_init(via_cputemp_init)
 386 module_exit(via_cputemp_exit)