1 /* 2 * thermal_hwmon.c - Generic Thermal Management hwmon support. 3 * 4 * Code based on Intel thermal_core.c. Copyrights of the original code: 5 * Copyright (C) 2008 Intel Corp 6 * Copyright (C) 2008 Zhang Rui <rui.zhang@intel.com> 7 * Copyright (C) 2008 Sujith Thomas <sujith.thomas@intel.com> 8 * 9 * Copyright (C) 2013 Texas Instruments 10 * Copyright (C) 2013 Eduardo Valentin <eduardo.valentin@ti.com> 11 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 12 * 13 * This program is free software; you can redistribute it and/or modify 14 * it under the terms of the GNU General Public License as published by 15 * the Free Software Foundation; version 2 of the License. 16 * 17 * This program is distributed in the hope that it will be useful, but 18 * WITHOUT ANY WARRANTY; without even the implied warranty of 19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 20 * General Public License for more details. 21 * 22 * You should have received a copy of the GNU General Public License along 23 * with this program; if not, write to the Free Software Foundation, Inc., 24 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. 25 * 26 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 27 */ 28 #include <linux/hwmon.h> 29 #include <linux/thermal.h> 30 #include <linux/slab.h> 31 #include <linux/err.h> 32 #include "thermal_hwmon.h" 33 34 /* hwmon sys I/F */ 35 /* thermal zone devices with the same type share one hwmon device */ 36 struct thermal_hwmon_device { 37 char type[THERMAL_NAME_LENGTH]; 38 struct device *device; 39 int count; 40 struct list_head tz_list; 41 struct list_head node; 42 }; 43 44 struct thermal_hwmon_attr { 45 struct device_attribute attr; 46 char name[16]; 47 }; 48 49 /* one temperature input for each thermal zone */ 50 struct thermal_hwmon_temp { 51 struct list_head hwmon_node; 52 struct thermal_zone_device *tz; 53 struct thermal_hwmon_attr temp_input; /* hwmon sys attr */ 54 struct thermal_hwmon_attr temp_crit; /* hwmon sys attr */ 55 }; 56 57 static LIST_HEAD(thermal_hwmon_list); 58 59 static DEFINE_MUTEX(thermal_hwmon_list_lock); 60 61 static ssize_t 62 temp_input_show(struct device *dev, struct device_attribute *attr, char *buf) 63 { 64 int temperature; 65 int ret; 66 struct thermal_hwmon_attr *hwmon_attr 67 = container_of(attr, struct thermal_hwmon_attr, attr); 68 struct thermal_hwmon_temp *temp 69 = container_of(hwmon_attr, struct thermal_hwmon_temp, 70 temp_input); 71 struct thermal_zone_device *tz = temp->tz; 72 73 ret = thermal_zone_get_temp(tz, &temperature); 74 75 if (ret) 76 return ret; 77 78 return sprintf(buf, "%d\n", temperature); 79 } 80 81 static ssize_t 82 temp_crit_show(struct device *dev, struct device_attribute *attr, char *buf) 83 { 84 struct thermal_hwmon_attr *hwmon_attr 85 = container_of(attr, struct thermal_hwmon_attr, attr); 86 struct thermal_hwmon_temp *temp 87 = container_of(hwmon_attr, struct thermal_hwmon_temp, 88 temp_crit); 89 struct thermal_zone_device *tz = temp->tz; 90 int temperature; 91 int ret; 92 93 ret = tz->ops->get_crit_temp(tz, &temperature); 94 if (ret) 95 return ret; 96 97 return sprintf(buf, "%d\n", temperature); 98 } 99 100 101 static struct thermal_hwmon_device * 102 thermal_hwmon_lookup_by_type(const struct thermal_zone_device *tz) 103 { 104 struct thermal_hwmon_device *hwmon; 105 106 mutex_lock(&thermal_hwmon_list_lock); 107 list_for_each_entry(hwmon, &thermal_hwmon_list, node) 108 if (!strcmp(hwmon->type, tz->type)) { 109 mutex_unlock(&thermal_hwmon_list_lock); 110 return hwmon; 111 } 112 mutex_unlock(&thermal_hwmon_list_lock); 113 114 return NULL; 115 } 116 117 /* Find the temperature input matching a given thermal zone */ 118 static struct thermal_hwmon_temp * 119 thermal_hwmon_lookup_temp(const struct thermal_hwmon_device *hwmon, 120 const struct thermal_zone_device *tz) 121 { 122 struct thermal_hwmon_temp *temp; 123 124 mutex_lock(&thermal_hwmon_list_lock); 125 list_for_each_entry(temp, &hwmon->tz_list, hwmon_node) 126 if (temp->tz == tz) { 127 mutex_unlock(&thermal_hwmon_list_lock); 128 return temp; 129 } 130 mutex_unlock(&thermal_hwmon_list_lock); 131 132 return NULL; 133 } 134 135 static bool thermal_zone_crit_temp_valid(struct thermal_zone_device *tz) 136 { 137 int temp; 138 return tz->ops->get_crit_temp && !tz->ops->get_crit_temp(tz, &temp); 139 } 140 141 int thermal_add_hwmon_sysfs(struct thermal_zone_device *tz) 142 { 143 struct thermal_hwmon_device *hwmon; 144 struct thermal_hwmon_temp *temp; 145 int new_hwmon_device = 1; 146 int result; 147 148 hwmon = thermal_hwmon_lookup_by_type(tz); 149 if (hwmon) { 150 new_hwmon_device = 0; 151 goto register_sys_interface; 152 } 153 154 hwmon = kzalloc(sizeof(*hwmon), GFP_KERNEL); 155 if (!hwmon) 156 return -ENOMEM; 157 158 INIT_LIST_HEAD(&hwmon->tz_list); 159 strlcpy(hwmon->type, tz->type, THERMAL_NAME_LENGTH); 160 hwmon->device = hwmon_device_register_with_info(NULL, hwmon->type, 161 hwmon, NULL, NULL); 162 if (IS_ERR(hwmon->device)) { 163 result = PTR_ERR(hwmon->device); 164 goto free_mem; 165 } 166 167 register_sys_interface: 168 temp = kzalloc(sizeof(*temp), GFP_KERNEL); 169 if (!temp) { 170 result = -ENOMEM; 171 goto unregister_name; 172 } 173 174 temp->tz = tz; 175 hwmon->count++; 176 177 snprintf(temp->temp_input.name, sizeof(temp->temp_input.name), 178 "temp%d_input", hwmon->count); 179 temp->temp_input.attr.attr.name = temp->temp_input.name; 180 temp->temp_input.attr.attr.mode = 0444; 181 temp->temp_input.attr.show = temp_input_show; 182 sysfs_attr_init(&temp->temp_input.attr.attr); 183 result = device_create_file(hwmon->device, &temp->temp_input.attr); 184 if (result) 185 goto free_temp_mem; 186 187 if (thermal_zone_crit_temp_valid(tz)) { 188 snprintf(temp->temp_crit.name, 189 sizeof(temp->temp_crit.name), 190 "temp%d_crit", hwmon->count); 191 temp->temp_crit.attr.attr.name = temp->temp_crit.name; 192 temp->temp_crit.attr.attr.mode = 0444; 193 temp->temp_crit.attr.show = temp_crit_show; 194 sysfs_attr_init(&temp->temp_crit.attr.attr); 195 result = device_create_file(hwmon->device, 196 &temp->temp_crit.attr); 197 if (result) 198 goto unregister_input; 199 } 200 201 mutex_lock(&thermal_hwmon_list_lock); 202 if (new_hwmon_device) 203 list_add_tail(&hwmon->node, &thermal_hwmon_list); 204 list_add_tail(&temp->hwmon_node, &hwmon->tz_list); 205 mutex_unlock(&thermal_hwmon_list_lock); 206 207 return 0; 208 209 unregister_input: 210 device_remove_file(hwmon->device, &temp->temp_input.attr); 211 free_temp_mem: 212 kfree(temp); 213 unregister_name: 214 if (new_hwmon_device) 215 hwmon_device_unregister(hwmon->device); 216 free_mem: 217 if (new_hwmon_device) 218 kfree(hwmon); 219 220 return result; 221 } 222 EXPORT_SYMBOL_GPL(thermal_add_hwmon_sysfs); 223 224 void thermal_remove_hwmon_sysfs(struct thermal_zone_device *tz) 225 { 226 struct thermal_hwmon_device *hwmon; 227 struct thermal_hwmon_temp *temp; 228 229 hwmon = thermal_hwmon_lookup_by_type(tz); 230 if (unlikely(!hwmon)) { 231 /* Should never happen... */ 232 dev_dbg(&tz->device, "hwmon device lookup failed!\n"); 233 return; 234 } 235 236 temp = thermal_hwmon_lookup_temp(hwmon, tz); 237 if (unlikely(!temp)) { 238 /* Should never happen... */ 239 dev_dbg(&tz->device, "temperature input lookup failed!\n"); 240 return; 241 } 242 243 device_remove_file(hwmon->device, &temp->temp_input.attr); 244 if (thermal_zone_crit_temp_valid(tz)) 245 device_remove_file(hwmon->device, &temp->temp_crit.attr); 246 247 mutex_lock(&thermal_hwmon_list_lock); 248 list_del(&temp->hwmon_node); 249 kfree(temp); 250 if (!list_empty(&hwmon->tz_list)) { 251 mutex_unlock(&thermal_hwmon_list_lock); 252 return; 253 } 254 list_del(&hwmon->node); 255 mutex_unlock(&thermal_hwmon_list_lock); 256 257 hwmon_device_unregister(hwmon->device); 258 kfree(hwmon); 259 } 260 EXPORT_SYMBOL_GPL(thermal_remove_hwmon_sysfs); 261