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 ret = tz->ops->get_crit_temp(tz, &temperature); 81 if (ret) 82 return ret; 83 84 return sprintf(buf, "%d\n", temperature); 85 } 86 87 88 static struct thermal_hwmon_device * 89 thermal_hwmon_lookup_by_type(const struct thermal_zone_device *tz) 90 { 91 struct thermal_hwmon_device *hwmon; 92 char type[THERMAL_NAME_LENGTH]; 93 94 mutex_lock(&thermal_hwmon_list_lock); 95 list_for_each_entry(hwmon, &thermal_hwmon_list, node) { 96 strcpy(type, tz->type); 97 strreplace(type, '-', '_'); 98 if (!strcmp(hwmon->type, type)) { 99 mutex_unlock(&thermal_hwmon_list_lock); 100 return hwmon; 101 } 102 } 103 mutex_unlock(&thermal_hwmon_list_lock); 104 105 return NULL; 106 } 107 108 /* Find the temperature input matching a given thermal zone */ 109 static struct thermal_hwmon_temp * 110 thermal_hwmon_lookup_temp(const struct thermal_hwmon_device *hwmon, 111 const struct thermal_zone_device *tz) 112 { 113 struct thermal_hwmon_temp *temp; 114 115 mutex_lock(&thermal_hwmon_list_lock); 116 list_for_each_entry(temp, &hwmon->tz_list, hwmon_node) 117 if (temp->tz == tz) { 118 mutex_unlock(&thermal_hwmon_list_lock); 119 return temp; 120 } 121 mutex_unlock(&thermal_hwmon_list_lock); 122 123 return NULL; 124 } 125 126 static bool thermal_zone_crit_temp_valid(struct thermal_zone_device *tz) 127 { 128 int temp; 129 return tz->ops->get_crit_temp && !tz->ops->get_crit_temp(tz, &temp); 130 } 131 132 int thermal_add_hwmon_sysfs(struct thermal_zone_device *tz) 133 { 134 struct thermal_hwmon_device *hwmon; 135 struct thermal_hwmon_temp *temp; 136 int new_hwmon_device = 1; 137 int result; 138 139 hwmon = thermal_hwmon_lookup_by_type(tz); 140 if (hwmon) { 141 new_hwmon_device = 0; 142 goto register_sys_interface; 143 } 144 145 hwmon = kzalloc(sizeof(*hwmon), GFP_KERNEL); 146 if (!hwmon) 147 return -ENOMEM; 148 149 INIT_LIST_HEAD(&hwmon->tz_list); 150 strlcpy(hwmon->type, tz->type, THERMAL_NAME_LENGTH); 151 strreplace(hwmon->type, '-', '_'); 152 hwmon->device = hwmon_device_register_with_info(&tz->device, hwmon->type, 153 hwmon, NULL, NULL); 154 if (IS_ERR(hwmon->device)) { 155 result = PTR_ERR(hwmon->device); 156 goto free_mem; 157 } 158 159 register_sys_interface: 160 temp = kzalloc(sizeof(*temp), GFP_KERNEL); 161 if (!temp) { 162 result = -ENOMEM; 163 goto unregister_name; 164 } 165 166 temp->tz = tz; 167 hwmon->count++; 168 169 snprintf(temp->temp_input.name, sizeof(temp->temp_input.name), 170 "temp%d_input", hwmon->count); 171 temp->temp_input.attr.attr.name = temp->temp_input.name; 172 temp->temp_input.attr.attr.mode = 0444; 173 temp->temp_input.attr.show = temp_input_show; 174 sysfs_attr_init(&temp->temp_input.attr.attr); 175 result = device_create_file(hwmon->device, &temp->temp_input.attr); 176 if (result) 177 goto free_temp_mem; 178 179 if (thermal_zone_crit_temp_valid(tz)) { 180 snprintf(temp->temp_crit.name, 181 sizeof(temp->temp_crit.name), 182 "temp%d_crit", hwmon->count); 183 temp->temp_crit.attr.attr.name = temp->temp_crit.name; 184 temp->temp_crit.attr.attr.mode = 0444; 185 temp->temp_crit.attr.show = temp_crit_show; 186 sysfs_attr_init(&temp->temp_crit.attr.attr); 187 result = device_create_file(hwmon->device, 188 &temp->temp_crit.attr); 189 if (result) 190 goto unregister_input; 191 } 192 193 mutex_lock(&thermal_hwmon_list_lock); 194 if (new_hwmon_device) 195 list_add_tail(&hwmon->node, &thermal_hwmon_list); 196 list_add_tail(&temp->hwmon_node, &hwmon->tz_list); 197 mutex_unlock(&thermal_hwmon_list_lock); 198 199 return 0; 200 201 unregister_input: 202 device_remove_file(hwmon->device, &temp->temp_input.attr); 203 free_temp_mem: 204 kfree(temp); 205 unregister_name: 206 if (new_hwmon_device) 207 hwmon_device_unregister(hwmon->device); 208 free_mem: 209 kfree(hwmon); 210 211 return result; 212 } 213 EXPORT_SYMBOL_GPL(thermal_add_hwmon_sysfs); 214 215 void thermal_remove_hwmon_sysfs(struct thermal_zone_device *tz) 216 { 217 struct thermal_hwmon_device *hwmon; 218 struct thermal_hwmon_temp *temp; 219 220 hwmon = thermal_hwmon_lookup_by_type(tz); 221 if (unlikely(!hwmon)) { 222 /* Should never happen... */ 223 dev_dbg(&tz->device, "hwmon device lookup failed!\n"); 224 return; 225 } 226 227 temp = thermal_hwmon_lookup_temp(hwmon, tz); 228 if (unlikely(!temp)) { 229 /* Should never happen... */ 230 dev_dbg(&tz->device, "temperature input lookup failed!\n"); 231 return; 232 } 233 234 device_remove_file(hwmon->device, &temp->temp_input.attr); 235 if (thermal_zone_crit_temp_valid(tz)) 236 device_remove_file(hwmon->device, &temp->temp_crit.attr); 237 238 mutex_lock(&thermal_hwmon_list_lock); 239 list_del(&temp->hwmon_node); 240 kfree(temp); 241 if (!list_empty(&hwmon->tz_list)) { 242 mutex_unlock(&thermal_hwmon_list_lock); 243 return; 244 } 245 list_del(&hwmon->node); 246 mutex_unlock(&thermal_hwmon_list_lock); 247 248 hwmon_device_unregister(hwmon->device); 249 kfree(hwmon); 250 } 251 EXPORT_SYMBOL_GPL(thermal_remove_hwmon_sysfs); 252 253 static void devm_thermal_hwmon_release(struct device *dev, void *res) 254 { 255 thermal_remove_hwmon_sysfs(*(struct thermal_zone_device **)res); 256 } 257 258 int devm_thermal_add_hwmon_sysfs(struct thermal_zone_device *tz) 259 { 260 struct thermal_zone_device **ptr; 261 int ret; 262 263 ptr = devres_alloc(devm_thermal_hwmon_release, sizeof(*ptr), 264 GFP_KERNEL); 265 if (!ptr) 266 return -ENOMEM; 267 268 ret = thermal_add_hwmon_sysfs(tz); 269 if (ret) { 270 devres_free(ptr); 271 return ret; 272 } 273 274 *ptr = tz; 275 devres_add(&tz->device, ptr); 276 277 return ret; 278 } 279 EXPORT_SYMBOL_GPL(devm_thermal_add_hwmon_sysfs); 280