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