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 name_show(struct device *dev, struct device_attribute *devattr, 64 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 temp_show(struct device *dev, struct device_attribute *devattr, 78 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_RO(temp1_input, temp, SHOW_TEMP); 106 static SENSOR_DEVICE_ATTR_RO(temp1_label, name, SHOW_LABEL); 107 static SENSOR_DEVICE_ATTR_RO(name, name, SHOW_NAME); 108 109 static struct attribute *via_cputemp_attributes[] = { 110 &sensor_dev_attr_name.dev_attr.attr, 111 &sensor_dev_attr_temp1_label.dev_attr.attr, 112 &sensor_dev_attr_temp1_input.dev_attr.attr, 113 NULL 114 }; 115 116 static const struct attribute_group via_cputemp_group = { 117 .attrs = via_cputemp_attributes, 118 }; 119 120 /* Optional attributes */ 121 static DEVICE_ATTR_RO(cpu0_vid); 122 123 static int via_cputemp_probe(struct platform_device *pdev) 124 { 125 struct via_cputemp_data *data; 126 struct cpuinfo_x86 *c = &cpu_data(pdev->id); 127 int err; 128 u32 eax, edx; 129 130 data = devm_kzalloc(&pdev->dev, sizeof(struct via_cputemp_data), 131 GFP_KERNEL); 132 if (!data) 133 return -ENOMEM; 134 135 data->id = pdev->id; 136 data->name = "via_cputemp"; 137 138 if (c->x86 == 7) { 139 data->msr_temp = 0x1423; 140 } else { 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 return -ENODEV; 155 } 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 return err; 164 } 165 166 platform_set_drvdata(pdev, data); 167 168 err = sysfs_create_group(&pdev->dev.kobj, &via_cputemp_group); 169 if (err) 170 return err; 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 return err; 196 } 197 198 static int via_cputemp_remove(struct platform_device *pdev) 199 { 200 struct via_cputemp_data *data = platform_get_drvdata(pdev); 201 202 hwmon_device_unregister(data->hwmon_dev); 203 if (data->vrm) 204 device_remove_file(&pdev->dev, &dev_attr_cpu0_vid); 205 sysfs_remove_group(&pdev->dev.kobj, &via_cputemp_group); 206 return 0; 207 } 208 209 static struct platform_driver via_cputemp_driver = { 210 .driver = { 211 .name = DRVNAME, 212 }, 213 .probe = via_cputemp_probe, 214 .remove = via_cputemp_remove, 215 }; 216 217 struct pdev_entry { 218 struct list_head list; 219 struct platform_device *pdev; 220 unsigned int cpu; 221 }; 222 223 static LIST_HEAD(pdev_list); 224 static DEFINE_MUTEX(pdev_list_mutex); 225 226 static int via_cputemp_online(unsigned int cpu) 227 { 228 int err; 229 struct platform_device *pdev; 230 struct pdev_entry *pdev_entry; 231 232 pdev = platform_device_alloc(DRVNAME, cpu); 233 if (!pdev) { 234 err = -ENOMEM; 235 pr_err("Device allocation failed\n"); 236 goto exit; 237 } 238 239 pdev_entry = kzalloc(sizeof(struct pdev_entry), GFP_KERNEL); 240 if (!pdev_entry) { 241 err = -ENOMEM; 242 goto exit_device_put; 243 } 244 245 err = platform_device_add(pdev); 246 if (err) { 247 pr_err("Device addition failed (%d)\n", err); 248 goto exit_device_free; 249 } 250 251 pdev_entry->pdev = pdev; 252 pdev_entry->cpu = cpu; 253 mutex_lock(&pdev_list_mutex); 254 list_add_tail(&pdev_entry->list, &pdev_list); 255 mutex_unlock(&pdev_list_mutex); 256 257 return 0; 258 259 exit_device_free: 260 kfree(pdev_entry); 261 exit_device_put: 262 platform_device_put(pdev); 263 exit: 264 return err; 265 } 266 267 static int via_cputemp_down_prep(unsigned int cpu) 268 { 269 struct pdev_entry *p; 270 271 mutex_lock(&pdev_list_mutex); 272 list_for_each_entry(p, &pdev_list, list) { 273 if (p->cpu == cpu) { 274 platform_device_unregister(p->pdev); 275 list_del(&p->list); 276 mutex_unlock(&pdev_list_mutex); 277 kfree(p); 278 return 0; 279 } 280 } 281 mutex_unlock(&pdev_list_mutex); 282 return 0; 283 } 284 285 static const struct x86_cpu_id __initconst cputemp_ids[] = { 286 { X86_VENDOR_CENTAUR, 6, 0xa, }, /* C7 A */ 287 { X86_VENDOR_CENTAUR, 6, 0xd, }, /* C7 D */ 288 { X86_VENDOR_CENTAUR, 6, 0xf, }, /* Nano */ 289 { X86_VENDOR_CENTAUR, 7, X86_MODEL_ANY, }, 290 {} 291 }; 292 MODULE_DEVICE_TABLE(x86cpu, cputemp_ids); 293 294 static enum cpuhp_state via_temp_online; 295 296 static int __init via_cputemp_init(void) 297 { 298 int err; 299 300 if (!x86_match_cpu(cputemp_ids)) 301 return -ENODEV; 302 303 err = platform_driver_register(&via_cputemp_driver); 304 if (err) 305 goto exit; 306 307 err = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "hwmon/via:online", 308 via_cputemp_online, via_cputemp_down_prep); 309 if (err < 0) 310 goto exit_driver_unreg; 311 via_temp_online = err; 312 313 #ifndef CONFIG_HOTPLUG_CPU 314 if (list_empty(&pdev_list)) { 315 err = -ENODEV; 316 goto exit_hp_unreg; 317 } 318 #endif 319 return 0; 320 321 #ifndef CONFIG_HOTPLUG_CPU 322 exit_hp_unreg: 323 cpuhp_remove_state_nocalls(via_temp_online); 324 #endif 325 exit_driver_unreg: 326 platform_driver_unregister(&via_cputemp_driver); 327 exit: 328 return err; 329 } 330 331 static void __exit via_cputemp_exit(void) 332 { 333 cpuhp_remove_state(via_temp_online); 334 platform_driver_unregister(&via_cputemp_driver); 335 } 336 337 MODULE_AUTHOR("Harald Welte <HaraldWelte@viatech.com>"); 338 MODULE_DESCRIPTION("VIA CPU temperature monitor"); 339 MODULE_LICENSE("GPL"); 340 341 module_init(via_cputemp_init) 342 module_exit(via_cputemp_exit) 343