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 .owner = THIS_MODULE, 209 .name = DRVNAME, 210 }, 211 .probe = via_cputemp_probe, 212 .remove = via_cputemp_remove, 213 }; 214 215 struct pdev_entry { 216 struct list_head list; 217 struct platform_device *pdev; 218 unsigned int cpu; 219 }; 220 221 static LIST_HEAD(pdev_list); 222 static DEFINE_MUTEX(pdev_list_mutex); 223 224 static int via_cputemp_device_add(unsigned int cpu) 225 { 226 int err; 227 struct platform_device *pdev; 228 struct pdev_entry *pdev_entry; 229 230 pdev = platform_device_alloc(DRVNAME, cpu); 231 if (!pdev) { 232 err = -ENOMEM; 233 pr_err("Device allocation failed\n"); 234 goto exit; 235 } 236 237 pdev_entry = kzalloc(sizeof(struct pdev_entry), GFP_KERNEL); 238 if (!pdev_entry) { 239 err = -ENOMEM; 240 goto exit_device_put; 241 } 242 243 err = platform_device_add(pdev); 244 if (err) { 245 pr_err("Device addition failed (%d)\n", err); 246 goto exit_device_free; 247 } 248 249 pdev_entry->pdev = pdev; 250 pdev_entry->cpu = cpu; 251 mutex_lock(&pdev_list_mutex); 252 list_add_tail(&pdev_entry->list, &pdev_list); 253 mutex_unlock(&pdev_list_mutex); 254 255 return 0; 256 257 exit_device_free: 258 kfree(pdev_entry); 259 exit_device_put: 260 platform_device_put(pdev); 261 exit: 262 return err; 263 } 264 265 static void via_cputemp_device_remove(unsigned int cpu) 266 { 267 struct pdev_entry *p; 268 269 mutex_lock(&pdev_list_mutex); 270 list_for_each_entry(p, &pdev_list, list) { 271 if (p->cpu == cpu) { 272 platform_device_unregister(p->pdev); 273 list_del(&p->list); 274 mutex_unlock(&pdev_list_mutex); 275 kfree(p); 276 return; 277 } 278 } 279 mutex_unlock(&pdev_list_mutex); 280 } 281 282 static int via_cputemp_cpu_callback(struct notifier_block *nfb, 283 unsigned long action, void *hcpu) 284 { 285 unsigned int cpu = (unsigned long) hcpu; 286 287 switch (action) { 288 case CPU_ONLINE: 289 case CPU_DOWN_FAILED: 290 via_cputemp_device_add(cpu); 291 break; 292 case CPU_DOWN_PREPARE: 293 via_cputemp_device_remove(cpu); 294 break; 295 } 296 return NOTIFY_OK; 297 } 298 299 static struct notifier_block via_cputemp_cpu_notifier __refdata = { 300 .notifier_call = via_cputemp_cpu_callback, 301 }; 302 303 static const struct x86_cpu_id __initconst cputemp_ids[] = { 304 { X86_VENDOR_CENTAUR, 6, 0xa, }, /* C7 A */ 305 { X86_VENDOR_CENTAUR, 6, 0xd, }, /* C7 D */ 306 { X86_VENDOR_CENTAUR, 6, 0xf, }, /* Nano */ 307 {} 308 }; 309 MODULE_DEVICE_TABLE(x86cpu, cputemp_ids); 310 311 static int __init via_cputemp_init(void) 312 { 313 int i, err; 314 315 if (!x86_match_cpu(cputemp_ids)) 316 return -ENODEV; 317 318 err = platform_driver_register(&via_cputemp_driver); 319 if (err) 320 goto exit; 321 322 cpu_notifier_register_begin(); 323 for_each_online_cpu(i) { 324 struct cpuinfo_x86 *c = &cpu_data(i); 325 326 if (c->x86 != 6) 327 continue; 328 329 if (c->x86_model < 0x0a) 330 continue; 331 332 if (c->x86_model > 0x0f) { 333 pr_warn("Unknown CPU model 0x%x\n", c->x86_model); 334 continue; 335 } 336 337 via_cputemp_device_add(i); 338 } 339 340 #ifndef CONFIG_HOTPLUG_CPU 341 if (list_empty(&pdev_list)) { 342 cpu_notifier_register_done(); 343 err = -ENODEV; 344 goto exit_driver_unreg; 345 } 346 #endif 347 348 __register_hotcpu_notifier(&via_cputemp_cpu_notifier); 349 cpu_notifier_register_done(); 350 return 0; 351 352 #ifndef CONFIG_HOTPLUG_CPU 353 exit_driver_unreg: 354 platform_driver_unregister(&via_cputemp_driver); 355 #endif 356 exit: 357 return err; 358 } 359 360 static void __exit via_cputemp_exit(void) 361 { 362 struct pdev_entry *p, *n; 363 364 cpu_notifier_register_begin(); 365 __unregister_hotcpu_notifier(&via_cputemp_cpu_notifier); 366 mutex_lock(&pdev_list_mutex); 367 list_for_each_entry_safe(p, n, &pdev_list, list) { 368 platform_device_unregister(p->pdev); 369 list_del(&p->list); 370 kfree(p); 371 } 372 mutex_unlock(&pdev_list_mutex); 373 cpu_notifier_register_done(); 374 platform_driver_unregister(&via_cputemp_driver); 375 } 376 377 MODULE_AUTHOR("Harald Welte <HaraldWelte@viatech.com>"); 378 MODULE_DESCRIPTION("VIA CPU temperature monitor"); 379 MODULE_LICENSE("GPL"); 380 381 module_init(via_cputemp_init) 382 module_exit(via_cputemp_exit) 383