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