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 */ 23struct 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 31struct thermal_hwmon_attr { 32 struct device_attribute attr; 33 char name[16]; 34}; 35 36/* one temperature input for each thermal zone */ 37struct 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 44static LIST_HEAD(thermal_hwmon_list); 45 46static DEFINE_MUTEX(thermal_hwmon_list_lock); 47 48static ssize_t 49temp_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 68static ssize_t 69temp_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 88static struct thermal_hwmon_device * 89thermal_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 */ 109static struct thermal_hwmon_temp * 110thermal_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 126static 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 132int 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 if (new_hwmon_device) 210 kfree(hwmon); 211 212 return result; 213} 214EXPORT_SYMBOL_GPL(thermal_add_hwmon_sysfs); 215 216void thermal_remove_hwmon_sysfs(struct thermal_zone_device *tz) 217{ 218 struct thermal_hwmon_device *hwmon; 219 struct thermal_hwmon_temp *temp; 220 221 hwmon = thermal_hwmon_lookup_by_type(tz); 222 if (unlikely(!hwmon)) { 223 /* Should never happen... */ 224 dev_dbg(&tz->device, "hwmon device lookup failed!\n"); 225 return; 226 } 227 228 temp = thermal_hwmon_lookup_temp(hwmon, tz); 229 if (unlikely(!temp)) { 230 /* Should never happen... */ 231 dev_dbg(&tz->device, "temperature input lookup failed!\n"); 232 return; 233 } 234 235 device_remove_file(hwmon->device, &temp->temp_input.attr); 236 if (thermal_zone_crit_temp_valid(tz)) 237 device_remove_file(hwmon->device, &temp->temp_crit.attr); 238 239 mutex_lock(&thermal_hwmon_list_lock); 240 list_del(&temp->hwmon_node); 241 kfree(temp); 242 if (!list_empty(&hwmon->tz_list)) { 243 mutex_unlock(&thermal_hwmon_list_lock); 244 return; 245 } 246 list_del(&hwmon->node); 247 mutex_unlock(&thermal_hwmon_list_lock); 248 249 hwmon_device_unregister(hwmon->device); 250 kfree(hwmon); 251} 252EXPORT_SYMBOL_GPL(thermal_remove_hwmon_sysfs); 253 254static void devm_thermal_hwmon_release(struct device *dev, void *res) 255{ 256 thermal_remove_hwmon_sysfs(*(struct thermal_zone_device **)res); 257} 258 259int devm_thermal_add_hwmon_sysfs(struct thermal_zone_device *tz) 260{ 261 struct thermal_zone_device **ptr; 262 int ret; 263 264 ptr = devres_alloc(devm_thermal_hwmon_release, sizeof(*ptr), 265 GFP_KERNEL); 266 if (!ptr) 267 return -ENOMEM; 268 269 ret = thermal_add_hwmon_sysfs(tz); 270 if (ret) { 271 devres_free(ptr); 272 return ret; 273 } 274 275 *ptr = tz; 276 devres_add(&tz->device, ptr); 277 278 return ret; 279} 280EXPORT_SYMBOL_GPL(devm_thermal_add_hwmon_sysfs); 281