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 */
24struct 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
32struct thermal_hwmon_attr {
33 struct device_attribute attr;
34 char name[16];
35};
36
37/* one temperature input for each thermal zone */
38struct 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
45static LIST_HEAD(thermal_hwmon_list);
46
47static DEFINE_MUTEX(thermal_hwmon_list_lock);
48
49static ssize_t
50temp_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, temp: &temperature);
62
63 if (ret)
64 return ret;
65
66 return sprintf(buf, fmt: "%d\n", temperature);
67}
68
69static ssize_t
70temp_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)(T: tz);
82
83 ret = tz->ops.get_crit_temp(tz, &temperature);
84 if (ret)
85 return ret;
86
87 return sprintf(buf, fmt: "%d\n", temperature);
88}
89
90
91static struct thermal_hwmon_device *
92thermal_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(lock: &thermal_hwmon_list_lock);
98 list_for_each_entry(hwmon, &thermal_hwmon_list, node) {
99 strscpy(type, tz->type);
100 strreplace(str: type, old: '-', new: '_');
101 if (!strcmp(hwmon->type, type)) {
102 mutex_unlock(lock: &thermal_hwmon_list_lock);
103 return hwmon;
104 }
105 }
106 mutex_unlock(lock: &thermal_hwmon_list_lock);
107
108 return NULL;
109}
110
111/* Find the temperature input matching a given thermal zone */
112static struct thermal_hwmon_temp *
113thermal_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(lock: &thermal_hwmon_list_lock);
119 list_for_each_entry(temp, &hwmon->tz_list, hwmon_node)
120 if (temp->tz == tz) {
121 mutex_unlock(lock: &thermal_hwmon_list_lock);
122 return temp;
123 }
124 mutex_unlock(lock: &thermal_hwmon_list_lock);
125
126 return NULL;
127}
128
129static 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
135int 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(list: &hwmon->tz_list);
153 strscpy(hwmon->type, tz->type, THERMAL_NAME_LENGTH);
154 strreplace(str: hwmon->type, old: '-', new: '_');
155 hwmon->device = hwmon_device_register_for_thermal(dev: &tz->device,
156 name: hwmon->type, drvdata: hwmon);
157 if (IS_ERR(ptr: hwmon->device)) {
158 result = PTR_ERR(ptr: 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(buf: temp->temp_input.name, size: sizeof(temp->temp_input.name),
173 fmt: "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(device: hwmon->device, entry: &temp->temp_input.attr);
179 if (result)
180 goto free_temp_mem;
181
182 if (thermal_zone_crit_temp_valid(tz)) {
183 snprintf(buf: temp->temp_crit.name,
184 size: sizeof(temp->temp_crit.name),
185 fmt: "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(device: hwmon->device,
191 entry: &temp->temp_crit.attr);
192 if (result)
193 goto unregister_input;
194 }
195
196 mutex_lock(lock: &thermal_hwmon_list_lock);
197 if (new_hwmon_device)
198 list_add_tail(new: &hwmon->node, head: &thermal_hwmon_list);
199 list_add_tail(new: &temp->hwmon_node, head: &hwmon->tz_list);
200 mutex_unlock(lock: &thermal_hwmon_list_lock);
201
202 return 0;
203
204 unregister_input:
205 device_remove_file(dev: hwmon->device, attr: &temp->temp_input.attr);
206 free_temp_mem:
207 kfree(objp: temp);
208 unregister_name:
209 if (new_hwmon_device)
210 hwmon_device_unregister(dev: hwmon->device);
211 free_mem:
212 kfree(objp: hwmon);
213
214 return result;
215}
216EXPORT_SYMBOL_GPL(thermal_add_hwmon_sysfs);
217
218void 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(dev: hwmon->device, attr: &temp->temp_input.attr);
238 if (thermal_zone_crit_temp_valid(tz))
239 device_remove_file(dev: hwmon->device, attr: &temp->temp_crit.attr);
240
241 mutex_lock(lock: &thermal_hwmon_list_lock);
242 list_del(entry: &temp->hwmon_node);
243 kfree(objp: temp);
244 if (!list_empty(head: &hwmon->tz_list)) {
245 mutex_unlock(lock: &thermal_hwmon_list_lock);
246 return;
247 }
248 list_del(entry: &hwmon->node);
249 mutex_unlock(lock: &thermal_hwmon_list_lock);
250
251 hwmon_device_unregister(dev: hwmon->device);
252 kfree(objp: hwmon);
253}
254EXPORT_SYMBOL_GPL(thermal_remove_hwmon_sysfs);
255
256static void devm_thermal_hwmon_release(struct device *dev, void *res)
257{
258 thermal_remove_hwmon_sysfs(*(struct thermal_zone_device **)res);
259}
260
261int 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(res: ptr);
277 return ret;
278 }
279
280 *ptr = tz;
281 devres_add(dev, res: ptr);
282
283 return ret;
284}
285EXPORT_SYMBOL_GPL(devm_thermal_add_hwmon_sysfs);
286
287MODULE_IMPORT_NS("HWMON_THERMAL");
288