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 cpu0_vid_show(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_RO(cpu0_vid); 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 if (c->x86 == 7) { 140 data->msr_temp = 0x1423; 141 } else { 142 switch (c->x86_model) { 143 case 0xA: 144 /* C7 A */ 145 case 0xD: 146 /* C7 D */ 147 data->msr_temp = 0x1169; 148 data->msr_vid = 0x198; 149 break; 150 case 0xF: 151 /* Nano */ 152 data->msr_temp = 0x1423; 153 break; 154 default: 155 return -ENODEV; 156 } 157 } 158 159 /* test if we can access the TEMPERATURE MSR */ 160 err = rdmsr_safe_on_cpu(data->id, data->msr_temp, &eax, &edx); 161 if (err) { 162 dev_err(&pdev->dev, 163 "Unable to access TEMPERATURE MSR, giving up\n"); 164 return err; 165 } 166 167 platform_set_drvdata(pdev, data); 168 169 err = sysfs_create_group(&pdev->dev.kobj, &via_cputemp_group); 170 if (err) 171 return err; 172 173 if (data->msr_vid) 174 data->vrm = vid_which_vrm(); 175 176 if (data->vrm) { 177 err = device_create_file(&pdev->dev, &dev_attr_cpu0_vid); 178 if (err) 179 goto exit_remove; 180 } 181 182 data->hwmon_dev = hwmon_device_register(&pdev->dev); 183 if (IS_ERR(data->hwmon_dev)) { 184 err = PTR_ERR(data->hwmon_dev); 185 dev_err(&pdev->dev, "Class registration failed (%d)\n", 186 err); 187 goto exit_remove; 188 } 189 190 return 0; 191 192 exit_remove: 193 if (data->vrm) 194 device_remove_file(&pdev->dev, &dev_attr_cpu0_vid); 195 sysfs_remove_group(&pdev->dev.kobj, &via_cputemp_group); 196 return err; 197 } 198 199 static int via_cputemp_remove(struct platform_device *pdev) 200 { 201 struct via_cputemp_data *data = platform_get_drvdata(pdev); 202 203 hwmon_device_unregister(data->hwmon_dev); 204 if (data->vrm) 205 device_remove_file(&pdev->dev, &dev_attr_cpu0_vid); 206 sysfs_remove_group(&pdev->dev.kobj, &via_cputemp_group); 207 return 0; 208 } 209 210 static struct platform_driver via_cputemp_driver = { 211 .driver = { 212 .name = DRVNAME, 213 }, 214 .probe = via_cputemp_probe, 215 .remove = via_cputemp_remove, 216 }; 217 218 struct pdev_entry { 219 struct list_head list; 220 struct platform_device *pdev; 221 unsigned int cpu; 222 }; 223 224 static LIST_HEAD(pdev_list); 225 static DEFINE_MUTEX(pdev_list_mutex); 226 227 static int via_cputemp_online(unsigned int cpu) 228 { 229 int err; 230 struct platform_device *pdev; 231 struct pdev_entry *pdev_entry; 232 233 pdev = platform_device_alloc(DRVNAME, cpu); 234 if (!pdev) { 235 err = -ENOMEM; 236 pr_err("Device allocation failed\n"); 237 goto exit; 238 } 239 240 pdev_entry = kzalloc(sizeof(struct pdev_entry), GFP_KERNEL); 241 if (!pdev_entry) { 242 err = -ENOMEM; 243 goto exit_device_put; 244 } 245 246 err = platform_device_add(pdev); 247 if (err) { 248 pr_err("Device addition failed (%d)\n", err); 249 goto exit_device_free; 250 } 251 252 pdev_entry->pdev = pdev; 253 pdev_entry->cpu = cpu; 254 mutex_lock(&pdev_list_mutex); 255 list_add_tail(&pdev_entry->list, &pdev_list); 256 mutex_unlock(&pdev_list_mutex); 257 258 return 0; 259 260 exit_device_free: 261 kfree(pdev_entry); 262 exit_device_put: 263 platform_device_put(pdev); 264 exit: 265 return err; 266 } 267 268 static int via_cputemp_down_prep(unsigned int cpu) 269 { 270 struct pdev_entry *p; 271 272 mutex_lock(&pdev_list_mutex); 273 list_for_each_entry(p, &pdev_list, list) { 274 if (p->cpu == cpu) { 275 platform_device_unregister(p->pdev); 276 list_del(&p->list); 277 mutex_unlock(&pdev_list_mutex); 278 kfree(p); 279 return 0; 280 } 281 } 282 mutex_unlock(&pdev_list_mutex); 283 return 0; 284 } 285 286 static const struct x86_cpu_id __initconst cputemp_ids[] = { 287 { X86_VENDOR_CENTAUR, 6, 0xa, }, /* C7 A */ 288 { X86_VENDOR_CENTAUR, 6, 0xd, }, /* C7 D */ 289 { X86_VENDOR_CENTAUR, 6, 0xf, }, /* Nano */ 290 { X86_VENDOR_CENTAUR, 7, X86_MODEL_ANY, }, 291 {} 292 }; 293 MODULE_DEVICE_TABLE(x86cpu, cputemp_ids); 294 295 static enum cpuhp_state via_temp_online; 296 297 static int __init via_cputemp_init(void) 298 { 299 int err; 300 301 if (!x86_match_cpu(cputemp_ids)) 302 return -ENODEV; 303 304 err = platform_driver_register(&via_cputemp_driver); 305 if (err) 306 goto exit; 307 308 err = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "hwmon/via:online", 309 via_cputemp_online, via_cputemp_down_prep); 310 if (err < 0) 311 goto exit_driver_unreg; 312 via_temp_online = err; 313 314 #ifndef CONFIG_HOTPLUG_CPU 315 if (list_empty(&pdev_list)) { 316 err = -ENODEV; 317 goto exit_hp_unreg; 318 } 319 #endif 320 return 0; 321 322 #ifndef CONFIG_HOTPLUG_CPU 323 exit_hp_unreg: 324 cpuhp_remove_state_nocalls(via_temp_online); 325 #endif 326 exit_driver_unreg: 327 platform_driver_unregister(&via_cputemp_driver); 328 exit: 329 return err; 330 } 331 332 static void __exit via_cputemp_exit(void) 333 { 334 cpuhp_remove_state(via_temp_online); 335 platform_driver_unregister(&via_cputemp_driver); 336 } 337 338 MODULE_AUTHOR("Harald Welte <HaraldWelte@viatech.com>"); 339 MODULE_DESCRIPTION("VIA CPU temperature monitor"); 340 MODULE_LICENSE("GPL"); 341 342 module_init(via_cputemp_init) 343 module_exit(via_cputemp_exit) 344