1 // SPDX-License-Identifier: GPL-2.0
3 * thermal_hwmon.c - Generic Thermal Management hwmon support.
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>
10 * Copyright (C) 2013 Texas Instruments
11 * Copyright (C) 2013 Eduardo Valentin <eduardo.valentin@ti.com>
13 #include <linux/hwmon.h>
14 #include <linux/thermal.h>
15 #include <linux/slab.h>
16 #include <linux/err.h>
17 #include "thermal_hwmon.h"
20 /* thermal zone devices with the same type share one hwmon device */
21 struct thermal_hwmon_device
{
22 char type
[THERMAL_NAME_LENGTH
];
23 struct device
*device
;
25 struct list_head tz_list
;
26 struct list_head node
;
29 struct thermal_hwmon_attr
{
30 struct device_attribute attr
;
34 /* one temperature input for each thermal zone */
35 struct thermal_hwmon_temp
{
36 struct list_head hwmon_node
;
37 struct thermal_zone_device
*tz
;
38 struct thermal_hwmon_attr temp_input
; /* hwmon sys attr */
39 struct thermal_hwmon_attr temp_crit
; /* hwmon sys attr */
42 static LIST_HEAD(thermal_hwmon_list
);
44 static DEFINE_MUTEX(thermal_hwmon_list_lock
);
47 temp_input_show(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
51 struct thermal_hwmon_attr
*hwmon_attr
52 = container_of(attr
, struct thermal_hwmon_attr
, attr
);
53 struct thermal_hwmon_temp
*temp
54 = container_of(hwmon_attr
, struct thermal_hwmon_temp
,
56 struct thermal_zone_device
*tz
= temp
->tz
;
58 ret
= thermal_zone_get_temp(tz
, &temperature
);
63 return sprintf(buf
, "%d\n", temperature
);
67 temp_crit_show(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
69 struct thermal_hwmon_attr
*hwmon_attr
70 = container_of(attr
, struct thermal_hwmon_attr
, attr
);
71 struct thermal_hwmon_temp
*temp
72 = container_of(hwmon_attr
, struct thermal_hwmon_temp
,
74 struct thermal_zone_device
*tz
= temp
->tz
;
78 ret
= tz
->ops
->get_crit_temp(tz
, &temperature
);
82 return sprintf(buf
, "%d\n", temperature
);
86 static struct thermal_hwmon_device
*
87 thermal_hwmon_lookup_by_type(const struct thermal_zone_device
*tz
)
89 struct thermal_hwmon_device
*hwmon
;
91 mutex_lock(&thermal_hwmon_list_lock
);
92 list_for_each_entry(hwmon
, &thermal_hwmon_list
, node
)
93 if (!strcmp(hwmon
->type
, tz
->type
)) {
94 mutex_unlock(&thermal_hwmon_list_lock
);
97 mutex_unlock(&thermal_hwmon_list_lock
);
102 /* Find the temperature input matching a given thermal zone */
103 static struct thermal_hwmon_temp
*
104 thermal_hwmon_lookup_temp(const struct thermal_hwmon_device
*hwmon
,
105 const struct thermal_zone_device
*tz
)
107 struct thermal_hwmon_temp
*temp
;
109 mutex_lock(&thermal_hwmon_list_lock
);
110 list_for_each_entry(temp
, &hwmon
->tz_list
, hwmon_node
)
111 if (temp
->tz
== tz
) {
112 mutex_unlock(&thermal_hwmon_list_lock
);
115 mutex_unlock(&thermal_hwmon_list_lock
);
120 static bool thermal_zone_crit_temp_valid(struct thermal_zone_device
*tz
)
123 return tz
->ops
->get_crit_temp
&& !tz
->ops
->get_crit_temp(tz
, &temp
);
126 int thermal_add_hwmon_sysfs(struct thermal_zone_device
*tz
)
128 struct thermal_hwmon_device
*hwmon
;
129 struct thermal_hwmon_temp
*temp
;
130 int new_hwmon_device
= 1;
133 hwmon
= thermal_hwmon_lookup_by_type(tz
);
135 new_hwmon_device
= 0;
136 goto register_sys_interface
;
139 hwmon
= kzalloc(sizeof(*hwmon
), GFP_KERNEL
);
143 INIT_LIST_HEAD(&hwmon
->tz_list
);
144 strlcpy(hwmon
->type
, tz
->type
, THERMAL_NAME_LENGTH
);
145 strreplace(hwmon
->type
, '-', '_');
146 hwmon
->device
= hwmon_device_register_with_info(NULL
, hwmon
->type
,
148 if (IS_ERR(hwmon
->device
)) {
149 result
= PTR_ERR(hwmon
->device
);
153 register_sys_interface
:
154 temp
= kzalloc(sizeof(*temp
), GFP_KERNEL
);
157 goto unregister_name
;
163 snprintf(temp
->temp_input
.name
, sizeof(temp
->temp_input
.name
),
164 "temp%d_input", hwmon
->count
);
165 temp
->temp_input
.attr
.attr
.name
= temp
->temp_input
.name
;
166 temp
->temp_input
.attr
.attr
.mode
= 0444;
167 temp
->temp_input
.attr
.show
= temp_input_show
;
168 sysfs_attr_init(&temp
->temp_input
.attr
.attr
);
169 result
= device_create_file(hwmon
->device
, &temp
->temp_input
.attr
);
173 if (thermal_zone_crit_temp_valid(tz
)) {
174 snprintf(temp
->temp_crit
.name
,
175 sizeof(temp
->temp_crit
.name
),
176 "temp%d_crit", hwmon
->count
);
177 temp
->temp_crit
.attr
.attr
.name
= temp
->temp_crit
.name
;
178 temp
->temp_crit
.attr
.attr
.mode
= 0444;
179 temp
->temp_crit
.attr
.show
= temp_crit_show
;
180 sysfs_attr_init(&temp
->temp_crit
.attr
.attr
);
181 result
= device_create_file(hwmon
->device
,
182 &temp
->temp_crit
.attr
);
184 goto unregister_input
;
187 mutex_lock(&thermal_hwmon_list_lock
);
188 if (new_hwmon_device
)
189 list_add_tail(&hwmon
->node
, &thermal_hwmon_list
);
190 list_add_tail(&temp
->hwmon_node
, &hwmon
->tz_list
);
191 mutex_unlock(&thermal_hwmon_list_lock
);
196 device_remove_file(hwmon
->device
, &temp
->temp_input
.attr
);
200 if (new_hwmon_device
)
201 hwmon_device_unregister(hwmon
->device
);
203 if (new_hwmon_device
)
208 EXPORT_SYMBOL_GPL(thermal_add_hwmon_sysfs
);
210 void thermal_remove_hwmon_sysfs(struct thermal_zone_device
*tz
)
212 struct thermal_hwmon_device
*hwmon
;
213 struct thermal_hwmon_temp
*temp
;
215 hwmon
= thermal_hwmon_lookup_by_type(tz
);
216 if (unlikely(!hwmon
)) {
217 /* Should never happen... */
218 dev_dbg(&tz
->device
, "hwmon device lookup failed!\n");
222 temp
= thermal_hwmon_lookup_temp(hwmon
, tz
);
223 if (unlikely(!temp
)) {
224 /* Should never happen... */
225 dev_dbg(&tz
->device
, "temperature input lookup failed!\n");
229 device_remove_file(hwmon
->device
, &temp
->temp_input
.attr
);
230 if (thermal_zone_crit_temp_valid(tz
))
231 device_remove_file(hwmon
->device
, &temp
->temp_crit
.attr
);
233 mutex_lock(&thermal_hwmon_list_lock
);
234 list_del(&temp
->hwmon_node
);
236 if (!list_empty(&hwmon
->tz_list
)) {
237 mutex_unlock(&thermal_hwmon_list_lock
);
240 list_del(&hwmon
->node
);
241 mutex_unlock(&thermal_hwmon_list_lock
);
243 hwmon_device_unregister(hwmon
->device
);
246 EXPORT_SYMBOL_GPL(thermal_remove_hwmon_sysfs
);