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 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 = devm_kzalloc(&pdev->dev, sizeof(struct via_cputemp_data),
 132                             GFP_KERNEL);
 133         if (!data)
 134                 return -ENOMEM;
 135
 136         data->id = pdev->id;
 137         data->name = "via_cputemp";
 138
 139         switch (c->x86_model) {
 140         case 0xA:
 141                 /* C7 A */
 142         case 0xD:
 143                 /* C7 D */
 144                 data->msr_temp = 0x1169;
 145                 data->msr_vid = 0x198;
 146                 break;
 147         case 0xF:
 148                 /* Nano */
 149                 data->msr_temp = 0x1423;
 150                 break;
 151         default:
 152                 return -ENODEV;
 153         }
 154
 155         /* test if we can access the TEMPERATURE MSR */
 156         err = rdmsr_safe_on_cpu(data->id, data->msr_temp, &eax, &edx);
 157         if (err) {
 158                 dev_err(&pdev->dev,
 159                         "Unable to access TEMPERATURE MSR, giving up\n");
 160                 return err;
 161         }
 162
 163         platform_set_drvdata(pdev, data);
 164
 165         err = sysfs_create_group(&pdev->dev.kobj, &via_cputemp_group);
 166         if (err)
 167                 return err;
 168
 169         if (data->msr_vid)
 170                 data->vrm = vid_which_vrm();
 171
 172         if (data->vrm) {
 173                 err = device_create_file(&pdev->dev, &dev_attr_cpu0_vid);
 174                 if (err)
 175                         goto exit_remove;
 176         }
 177
 178         data->hwmon_dev = hwmon_device_register(&pdev->dev);
 179         if (IS_ERR(data->hwmon_dev)) {
 180                 err = PTR_ERR(data->hwmon_dev);
 181                 dev_err(&pdev->dev, "Class registration failed (%d)\n",
 182                         err);
 183                 goto exit_remove;
 184         }
 185
 186         return 0;
 187
 188 exit_remove:
 189         if (data->vrm)
 190                 device_remove_file(&pdev->dev, &dev_attr_cpu0_vid);
 191         sysfs_remove_group(&pdev->dev.kobj, &via_cputemp_group);
 192         return err;
 193 }
 194
 195 static int via_cputemp_remove(struct platform_device *pdev)
 196 {
 197         struct via_cputemp_data *data = platform_get_drvdata(pdev);
 198
 199         hwmon_device_unregister(data->hwmon_dev);
 200         if (data->vrm)
 201                 device_remove_file(&pdev->dev, &dev_attr_cpu0_vid);
 202         sysfs_remove_group(&pdev->dev.kobj, &via_cputemp_group);
 203         return 0;
 204 }
 205
 206 static struct platform_driver via_cputemp_driver = {
 207         .driver = {
 208                 .name = DRVNAME,
 209         },
 210         .probe = via_cputemp_probe,
 211         .remove = via_cputemp_remove,
 212 };
 213
 214 struct pdev_entry {
 215         struct list_head list;
 216         struct platform_device *pdev;
 217         unsigned int cpu;
 218 };
 219
 220 static LIST_HEAD(pdev_list);
 221 static DEFINE_MUTEX(pdev_list_mutex);
 222
 223 static int via_cputemp_online(unsigned int cpu)
 224 {
 225         int err;
 226         struct platform_device *pdev;
 227         struct pdev_entry *pdev_entry;
 228
 229         pdev = platform_device_alloc(DRVNAME, cpu);
 230         if (!pdev) {
 231                 err = -ENOMEM;
 232                 pr_err("Device allocation failed\n");
 233                 goto exit;
 234         }
 235
 236         pdev_entry = kzalloc(sizeof(struct pdev_entry), GFP_KERNEL);
 237         if (!pdev_entry) {
 238                 err = -ENOMEM;
 239                 goto exit_device_put;
 240         }
 241
 242         err = platform_device_add(pdev);
 243         if (err) {
 244                 pr_err("Device addition failed (%d)\n", err);
 245                 goto exit_device_free;
 246         }
 247
 248         pdev_entry->pdev = pdev;
 249         pdev_entry->cpu = cpu;
 250         mutex_lock(&pdev_list_mutex);
 251         list_add_tail(&pdev_entry->list, &pdev_list);
 252         mutex_unlock(&pdev_list_mutex);
 253
 254         return 0;
 255
 256 exit_device_free:
 257         kfree(pdev_entry);
 258 exit_device_put:
 259         platform_device_put(pdev);
 260 exit:
 261         return err;
 262 }
 263
 264 static int via_cputemp_down_prep(unsigned int cpu)
 265 {
 266         struct pdev_entry *p;
 267
 268         mutex_lock(&pdev_list_mutex);
 269         list_for_each_entry(p, &pdev_list, list) {
 270                 if (p->cpu == cpu) {
 271                         platform_device_unregister(p->pdev);
 272                         list_del(&p->list);
 273                         mutex_unlock(&pdev_list_mutex);
 274                         kfree(p);
 275                         return 0;
 276                 }
 277         }
 278         mutex_unlock(&pdev_list_mutex);
 279         return 0;
 280 }
 281
 282 static const struct x86_cpu_id __initconst cputemp_ids[] = {
 283         { X86_VENDOR_CENTAUR, 6, 0xa, }, /* C7 A */
 284         { X86_VENDOR_CENTAUR, 6, 0xd, }, /* C7 D */
 285         { X86_VENDOR_CENTAUR, 6, 0xf, }, /* Nano */
 286         {}
 287 };
 288 MODULE_DEVICE_TABLE(x86cpu, cputemp_ids);
 289
 290 static enum cpuhp_state via_temp_online;
 291
 292 static int __init via_cputemp_init(void)
 293 {
 294         int err;
 295
 296         if (!x86_match_cpu(cputemp_ids))
 297                 return -ENODEV;
 298
 299         err = platform_driver_register(&via_cputemp_driver);
 300         if (err)
 301                 goto exit;
 302
 303         err = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "hwmon/via:online",
 304                                 via_cputemp_online, via_cputemp_down_prep);
 305         if (err < 0)
 306                 goto exit_driver_unreg;
 307         via_temp_online = err;
 308
 309 #ifndef CONFIG_HOTPLUG_CPU
 310         if (list_empty(&pdev_list)) {
 311                 err = -ENODEV;
 312                 goto exit_hp_unreg;
 313         }
 314 #endif
 315         return 0;
 316
 317 #ifndef CONFIG_HOTPLUG_CPU
 318 exit_hp_unreg:
 319         cpuhp_remove_state_nocalls(via_temp_online);
 320 #endif
 321 exit_driver_unreg:
 322         platform_driver_unregister(&via_cputemp_driver);
 323 exit:
 324         return err;
 325 }
 326
 327 static void __exit via_cputemp_exit(void)
 328 {
 329         cpuhp_remove_state(via_temp_online);
 330         platform_driver_unregister(&via_cputemp_driver);
 331 }
 332
 333 MODULE_AUTHOR("Harald Welte <HaraldWelte@viatech.com>");
 334 MODULE_DESCRIPTION("VIA CPU temperature monitor");
 335 MODULE_LICENSE("GPL");
 336
 337 module_init(via_cputemp_init)
 338 module_exit(via_cputemp_exit)