1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * thermal_hwmon.c - Generic Thermal Management hwmon support. 4 * 5 * Code based on Intel thermal_core.c. Copyrights of the original code: 6 * Copyright (C) 2008 Intel Corp 7 * Copyright (C) 2008 Zhang Rui <rui.zhang@intel.com> 8 * Copyright (C) 2008 Sujith Thomas <sujith.thomas@intel.com> 9 * 10 * Copyright (C) 2013 Texas Instruments 11 * Copyright (C) 2013 Eduardo Valentin <eduardo.valentin@ti.com> 12 */ 13 #include <linux/err.h> 14 #include <linux/export.h> 15 #include <linux/hwmon.h> 16 #include <linux/slab.h> 17 #include <linux/thermal.h> 18 19 #include "thermal_hwmon.h" 20 21 /* hwmon sys I/F */ 22 /* thermal zone devices with the same type share one hwmon device */ 23 struct thermal_hwmon_device { 24 char type[THERMAL_NAME_LENGTH]; 25 struct device *device; 26 int count; 27 struct list_head tz_list; 28 struct list_head node; 29 }; 30 31 struct thermal_hwmon_attr { 32 struct device_attribute attr; 33 char name[16]; 34 }; 35 36 /* one temperature input for each thermal zone */ 37 struct thermal_hwmon_temp { 38 struct list_head hwmon_node; 39 struct thermal_zone_device *tz; 40 struct thermal_hwmon_attr temp_input; /* hwmon sys attr */ 41 struct thermal_hwmon_attr temp_crit; /* hwmon sys attr */ 42 }; 43 44 static LIST_HEAD(thermal_hwmon_list); 45 46 static DEFINE_MUTEX(thermal_hwmon_list_lock); 47 48 static ssize_t 49 temp_input_show(struct device *dev, struct device_attribute *attr, char *buf) 50 { 51 int temperature; 52 int ret; 53 struct thermal_hwmon_attr *hwmon_attr 54 = container_of(attr, struct thermal_hwmon_attr, attr); 55 struct thermal_hwmon_temp *temp 56 = container_of(hwmon_attr, struct thermal_hwmon_temp, 57 temp_input); 58 struct thermal_zone_device *tz = temp->tz; 59 60 ret = thermal_zone_get_temp(tz, &temperature); 61 62 if (ret) 63 return ret; 64 65 return sprintf(buf, "%d\n", temperature); 66 } 67 68 static ssize_t 69 temp_crit_show(struct device *dev, struct device_attribute *attr, char *buf) 70 { 71 struct thermal_hwmon_attr *hwmon_attr 72 = container_of(attr, struct thermal_hwmon_attr, attr); 73 struct thermal_hwmon_temp *temp 74 = container_of(hwmon_attr, struct thermal_hwmon_temp, 75 temp_crit); 76 struct thermal_zone_device *tz = temp->tz; 77 int temperature; 78 int ret; 79 80 mutex_lock(&tz->lock); 81 82 if (device_is_registered(&tz->device)) 83 ret = tz->ops->get_crit_temp(tz, &temperature); 84 else 85 ret = -ENODEV; 86 87 mutex_unlock(&tz->lock); 88 89 if (ret) 90 return ret; 91 92 return sprintf(buf, "%d\n", temperature); 93 } 94 95 96 static struct thermal_hwmon_device * 97 thermal_hwmon_lookup_by_type(const struct thermal_zone_device *tz) 98 { 99 struct thermal_hwmon_device *hwmon; 100 char type[THERMAL_NAME_LENGTH]; 101 102 mutex_lock(&thermal_hwmon_list_lock); 103 list_for_each_entry(hwmon, &thermal_hwmon_list, node) { 104 strcpy(type, tz->type); 105 strreplace(type, '-', '_'); 106 if (!strcmp(hwmon->type, type)) { 107 mutex_unlock(&thermal_hwmon_list_lock); 108 return hwmon; 109 } 110 } 111 mutex_unlock(&thermal_hwmon_list_lock); 112 113 return NULL; 114 } 115 116 /* Find the temperature input matching a given thermal zone */ 117 static struct thermal_hwmon_temp * 118 thermal_hwmon_lookup_temp(const struct thermal_hwmon_device *hwmon, 119 const struct thermal_zone_device *tz) 120 { 121 struct thermal_hwmon_temp *temp; 122 123 mutex_lock(&thermal_hwmon_list_lock); 124 list_for_each_entry(temp, &hwmon->tz_list, hwmon_node) 125 if (temp->tz == tz) { 126 mutex_unlock(&thermal_hwmon_list_lock); 127 return temp; 128 } 129 mutex_unlock(&thermal_hwmon_list_lock); 130 131 return NULL; 132 } 133 134 static bool thermal_zone_crit_temp_valid(struct thermal_zone_device *tz) 135 { 136 int temp; 137 return tz->ops->get_crit_temp && !tz->ops->get_crit_temp(tz, &temp); 138 } 139 140 int thermal_add_hwmon_sysfs(struct thermal_zone_device *tz) 141 { 142 struct thermal_hwmon_device *hwmon; 143 struct thermal_hwmon_temp *temp; 144 int new_hwmon_device = 1; 145 int result; 146 147 hwmon = thermal_hwmon_lookup_by_type(tz); 148 if (hwmon) { 149 new_hwmon_device = 0; 150 goto register_sys_interface; 151 } 152 153 hwmon = kzalloc(sizeof(*hwmon), GFP_KERNEL); 154 if (!hwmon) 155 return -ENOMEM; 156 157 INIT_LIST_HEAD(&hwmon->tz_list); 158 strscpy(hwmon->type, tz->type, THERMAL_NAME_LENGTH); 159 strreplace(hwmon->type, '-', '_'); 160 hwmon->device = hwmon_device_register_for_thermal(&tz->device, 161 hwmon->type, hwmon); 162 if (IS_ERR(hwmon->device)) { 163 result = PTR_ERR(hwmon->device); 164 goto free_mem; 165 } 166 167 register_sys_interface: 168 temp = kzalloc(sizeof(*temp), GFP_KERNEL); 169 if (!temp) { 170 result = -ENOMEM; 171 goto unregister_name; 172 } 173 174 temp->tz = tz; 175 hwmon->count++; 176 177 snprintf(temp->temp_input.name, sizeof(temp->temp_input.name), 178 "temp%d_input", hwmon->count); 179 temp->temp_input.attr.attr.name = temp->temp_input.name; 180 temp->temp_input.attr.attr.mode = 0444; 181 temp->temp_input.attr.show = temp_input_show; 182 sysfs_attr_init(&temp->temp_input.attr.attr); 183 result = device_create_file(hwmon->device, &temp->temp_input.attr); 184 if (result) 185 goto free_temp_mem; 186 187 if (thermal_zone_crit_temp_valid(tz)) { 188 snprintf(temp->temp_crit.name, 189 sizeof(temp->temp_crit.name), 190 "temp%d_crit", hwmon->count); 191 temp->temp_crit.attr.attr.name = temp->temp_crit.name; 192 temp->temp_crit.attr.attr.mode = 0444; 193 temp->temp_crit.attr.show = temp_crit_show; 194 sysfs_attr_init(&temp->temp_crit.attr.attr); 195 result = device_create_file(hwmon->device, 196 &temp->temp_crit.attr); 197 if (result) 198 goto unregister_input; 199 } 200 201 mutex_lock(&thermal_hwmon_list_lock); 202 if (new_hwmon_device) 203 list_add_tail(&hwmon->node, &thermal_hwmon_list); 204 list_add_tail(&temp->hwmon_node, &hwmon->tz_list); 205 mutex_unlock(&thermal_hwmon_list_lock); 206 207 return 0; 208 209 unregister_input: 210 device_remove_file(hwmon->device, &temp->temp_input.attr); 211 free_temp_mem: 212 kfree(temp); 213 unregister_name: 214 if (new_hwmon_device) 215 hwmon_device_unregister(hwmon->device); 216 free_mem: 217 kfree(hwmon); 218 219 return result; 220 } 221 EXPORT_SYMBOL_GPL(thermal_add_hwmon_sysfs); 222 223 void thermal_remove_hwmon_sysfs(struct thermal_zone_device *tz) 224 { 225 struct thermal_hwmon_device *hwmon; 226 struct thermal_hwmon_temp *temp; 227 228 hwmon = thermal_hwmon_lookup_by_type(tz); 229 if (unlikely(!hwmon)) { 230 /* Should never happen... */ 231 dev_dbg(&tz->device, "hwmon device lookup failed!\n"); 232 return; 233 } 234 235 temp = thermal_hwmon_lookup_temp(hwmon, tz); 236 if (unlikely(!temp)) { 237 /* Should never happen... */ 238 dev_dbg(&tz->device, "temperature input lookup failed!\n"); 239 return; 240 } 241 242 device_remove_file(hwmon->device, &temp->temp_input.attr); 243 if (thermal_zone_crit_temp_valid(tz)) 244 device_remove_file(hwmon->device, &temp->temp_crit.attr); 245 246 mutex_lock(&thermal_hwmon_list_lock); 247 list_del(&temp->hwmon_node); 248 kfree(temp); 249 if (!list_empty(&hwmon->tz_list)) { 250 mutex_unlock(&thermal_hwmon_list_lock); 251 return; 252 } 253 list_del(&hwmon->node); 254 mutex_unlock(&thermal_hwmon_list_lock); 255 256 hwmon_device_unregister(hwmon->device); 257 kfree(hwmon); 258 } 259 EXPORT_SYMBOL_GPL(thermal_remove_hwmon_sysfs); 260 261 static void devm_thermal_hwmon_release(struct device *dev, void *res) 262 { 263 thermal_remove_hwmon_sysfs(*(struct thermal_zone_device **)res); 264 } 265 266 int devm_thermal_add_hwmon_sysfs(struct thermal_zone_device *tz) 267 { 268 struct thermal_zone_device **ptr; 269 int ret; 270 271 ptr = devres_alloc(devm_thermal_hwmon_release, sizeof(*ptr), 272 GFP_KERNEL); 273 if (!ptr) 274 return -ENOMEM; 275 276 ret = thermal_add_hwmon_sysfs(tz); 277 if (ret) { 278 devres_free(ptr); 279 return ret; 280 } 281 282 *ptr = tz; 283 devres_add(&tz->device, ptr); 284 285 return ret; 286 } 287 EXPORT_SYMBOL_GPL(devm_thermal_add_hwmon_sysfs); 288 289 MODULE_IMPORT_NS(HWMON_THERMAL); 290