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 #include "thermal_core.h" 21 22 /* hwmon sys I/F */ 23 /* thermal zone devices with the same type share one hwmon device */ 24 struct thermal_hwmon_device { 25 char type[THERMAL_NAME_LENGTH]; 26 struct device *device; 27 int count; 28 struct list_head tz_list; 29 struct list_head node; 30 }; 31 32 struct thermal_hwmon_attr { 33 struct device_attribute attr; 34 char name[16]; 35 }; 36 37 /* one temperature input for each thermal zone */ 38 struct thermal_hwmon_temp { 39 struct list_head hwmon_node; 40 struct thermal_zone_device *tz; 41 struct thermal_hwmon_attr temp_input; /* hwmon sys attr */ 42 struct thermal_hwmon_attr temp_crit; /* hwmon sys attr */ 43 bool temp_crit_present; 44 }; 45 46 static LIST_HEAD(thermal_hwmon_list); 47 48 static DEFINE_MUTEX(thermal_hwmon_list_lock); 49 50 static ssize_t 51 temp_input_show(struct device *dev, struct device_attribute *attr, char *buf) 52 { 53 int temperature; 54 int ret; 55 struct thermal_hwmon_attr *hwmon_attr 56 = container_of(attr, struct thermal_hwmon_attr, attr); 57 struct thermal_hwmon_temp *temp 58 = container_of(hwmon_attr, struct thermal_hwmon_temp, 59 temp_input); 60 struct thermal_zone_device *tz = temp->tz; 61 62 ret = thermal_zone_get_temp(tz, &temperature); 63 64 if (ret) 65 return ret; 66 67 return sysfs_emit(buf, "%d\n", temperature); 68 } 69 70 static ssize_t 71 temp_crit_show(struct device *dev, struct device_attribute *attr, char *buf) 72 { 73 struct thermal_hwmon_attr *hwmon_attr 74 = container_of(attr, struct thermal_hwmon_attr, attr); 75 struct thermal_hwmon_temp *temp 76 = container_of(hwmon_attr, struct thermal_hwmon_temp, 77 temp_crit); 78 struct thermal_zone_device *tz = temp->tz; 79 int temperature; 80 int ret; 81 82 guard(thermal_zone)(tz); 83 84 ret = tz->ops.get_crit_temp(tz, &temperature); 85 if (ret) 86 return ret; 87 88 return sysfs_emit(buf, "%d\n", temperature); 89 } 90 91 92 static struct thermal_hwmon_device * 93 thermal_hwmon_lookup_by_type(const struct thermal_zone_device *tz) 94 { 95 struct thermal_hwmon_device *hwmon; 96 char type[THERMAL_NAME_LENGTH]; 97 98 mutex_lock(&thermal_hwmon_list_lock); 99 list_for_each_entry(hwmon, &thermal_hwmon_list, node) { 100 strscpy(type, tz->type); 101 strreplace(type, '-', '_'); 102 if (!strcmp(hwmon->type, type)) { 103 mutex_unlock(&thermal_hwmon_list_lock); 104 return hwmon; 105 } 106 } 107 mutex_unlock(&thermal_hwmon_list_lock); 108 109 return NULL; 110 } 111 112 /* Find the temperature input matching a given thermal zone */ 113 static struct thermal_hwmon_temp * 114 thermal_hwmon_lookup_temp(const struct thermal_hwmon_device *hwmon, 115 const struct thermal_zone_device *tz) 116 { 117 struct thermal_hwmon_temp *temp; 118 119 mutex_lock(&thermal_hwmon_list_lock); 120 list_for_each_entry(temp, &hwmon->tz_list, hwmon_node) 121 if (temp->tz == tz) { 122 mutex_unlock(&thermal_hwmon_list_lock); 123 return temp; 124 } 125 mutex_unlock(&thermal_hwmon_list_lock); 126 127 return NULL; 128 } 129 130 static bool thermal_zone_crit_temp_valid(struct thermal_zone_device *tz) 131 { 132 int temp; 133 return tz->ops.get_crit_temp && !tz->ops.get_crit_temp(tz, &temp); 134 } 135 136 int thermal_add_hwmon_sysfs(struct thermal_zone_device *tz) 137 { 138 struct thermal_hwmon_device *hwmon; 139 struct thermal_hwmon_temp *temp; 140 int new_hwmon_device = 1; 141 int result; 142 143 hwmon = thermal_hwmon_lookup_by_type(tz); 144 if (hwmon) { 145 new_hwmon_device = 0; 146 goto register_sys_interface; 147 } 148 149 hwmon = kzalloc_obj(*hwmon); 150 if (!hwmon) 151 return -ENOMEM; 152 153 INIT_LIST_HEAD(&hwmon->tz_list); 154 strscpy(hwmon->type, tz->type, THERMAL_NAME_LENGTH); 155 strreplace(hwmon->type, '-', '_'); 156 hwmon->device = hwmon_device_register_for_thermal(&tz->device, 157 hwmon->type, hwmon); 158 if (IS_ERR(hwmon->device)) { 159 result = PTR_ERR(hwmon->device); 160 goto free_mem; 161 } 162 163 register_sys_interface: 164 temp = kzalloc_obj(*temp); 165 if (!temp) { 166 result = -ENOMEM; 167 goto unregister_name; 168 } 169 170 temp->tz = tz; 171 hwmon->count++; 172 173 snprintf(temp->temp_input.name, sizeof(temp->temp_input.name), 174 "temp%d_input", hwmon->count); 175 temp->temp_input.attr.attr.name = temp->temp_input.name; 176 temp->temp_input.attr.attr.mode = 0444; 177 temp->temp_input.attr.show = temp_input_show; 178 sysfs_attr_init(&temp->temp_input.attr.attr); 179 result = device_create_file(hwmon->device, &temp->temp_input.attr); 180 if (result) 181 goto free_temp_mem; 182 183 if (thermal_zone_crit_temp_valid(tz)) { 184 snprintf(temp->temp_crit.name, 185 sizeof(temp->temp_crit.name), 186 "temp%d_crit", hwmon->count); 187 temp->temp_crit.attr.attr.name = temp->temp_crit.name; 188 temp->temp_crit.attr.attr.mode = 0444; 189 temp->temp_crit.attr.show = temp_crit_show; 190 sysfs_attr_init(&temp->temp_crit.attr.attr); 191 result = device_create_file(hwmon->device, 192 &temp->temp_crit.attr); 193 if (result) 194 goto unregister_input; 195 196 temp->temp_crit_present = true; 197 } 198 199 mutex_lock(&thermal_hwmon_list_lock); 200 if (new_hwmon_device) 201 list_add_tail(&hwmon->node, &thermal_hwmon_list); 202 list_add_tail(&temp->hwmon_node, &hwmon->tz_list); 203 mutex_unlock(&thermal_hwmon_list_lock); 204 205 return 0; 206 207 unregister_input: 208 device_remove_file(hwmon->device, &temp->temp_input.attr); 209 free_temp_mem: 210 kfree(temp); 211 unregister_name: 212 if (new_hwmon_device) 213 hwmon_device_unregister(hwmon->device); 214 free_mem: 215 if (new_hwmon_device) 216 kfree(hwmon); 217 218 return result; 219 } 220 EXPORT_SYMBOL_GPL(thermal_add_hwmon_sysfs); 221 222 void thermal_remove_hwmon_sysfs(struct thermal_zone_device *tz) 223 { 224 struct thermal_hwmon_device *hwmon; 225 struct thermal_hwmon_temp *temp; 226 227 hwmon = thermal_hwmon_lookup_by_type(tz); 228 if (unlikely(!hwmon)) { 229 /* Should never happen... */ 230 dev_dbg(&tz->device, "hwmon device lookup failed!\n"); 231 return; 232 } 233 234 temp = thermal_hwmon_lookup_temp(hwmon, tz); 235 if (unlikely(!temp)) { 236 /* Should never happen... */ 237 dev_dbg(&tz->device, "temperature input lookup failed!\n"); 238 return; 239 } 240 241 device_remove_file(hwmon->device, &temp->temp_input.attr); 242 if (temp->temp_crit_present) 243 device_remove_file(hwmon->device, &temp->temp_crit.attr); 244 245 mutex_lock(&thermal_hwmon_list_lock); 246 list_del(&temp->hwmon_node); 247 kfree(temp); 248 if (!list_empty(&hwmon->tz_list)) { 249 mutex_unlock(&thermal_hwmon_list_lock); 250 return; 251 } 252 list_del(&hwmon->node); 253 mutex_unlock(&thermal_hwmon_list_lock); 254 255 hwmon_device_unregister(hwmon->device); 256 kfree(hwmon); 257 } 258 EXPORT_SYMBOL_GPL(thermal_remove_hwmon_sysfs); 259 260 static void devm_thermal_hwmon_release(struct device *dev, void *res) 261 { 262 thermal_remove_hwmon_sysfs(*(struct thermal_zone_device **)res); 263 } 264 265 int devm_thermal_add_hwmon_sysfs(struct device *dev, struct thermal_zone_device *tz) 266 { 267 struct thermal_zone_device **ptr; 268 int ret; 269 270 ptr = devres_alloc(devm_thermal_hwmon_release, sizeof(*ptr), 271 GFP_KERNEL); 272 if (!ptr) { 273 dev_warn(dev, "Failed to allocate device resource data\n"); 274 return -ENOMEM; 275 } 276 277 ret = thermal_add_hwmon_sysfs(tz); 278 if (ret) { 279 dev_warn(dev, "Failed to add hwmon sysfs attributes\n"); 280 devres_free(ptr); 281 return ret; 282 } 283 284 *ptr = tz; 285 devres_add(dev, ptr); 286 287 return ret; 288 } 289 EXPORT_SYMBOL_GPL(devm_thermal_add_hwmon_sysfs); 290 291 MODULE_IMPORT_NS("HWMON_THERMAL"); 292