Merge tag 'usb-ci-v4.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/peter...
[linux-2.6-microblaze.git] / drivers / thermal / thermal_hwmon.c
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);