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 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) 339