Merge tag 'regulator-fix-v4.10-rc6' of git://git.kernel.org/pub/scm/linux/kernel...
[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 name_show(struct device *dev, struct device_attribute *attr, char *buf)
63 {
64         struct thermal_hwmon_device *hwmon = dev_get_drvdata(dev);
65         return sprintf(buf, "%s\n", hwmon->type);
66 }
67 static DEVICE_ATTR_RO(name);
68
69 static ssize_t
70 temp_input_show(struct device *dev, struct device_attribute *attr, char *buf)
71 {
72         int temperature;
73         int ret;
74         struct thermal_hwmon_attr *hwmon_attr
75                         = container_of(attr, struct thermal_hwmon_attr, attr);
76         struct thermal_hwmon_temp *temp
77                         = container_of(hwmon_attr, struct thermal_hwmon_temp,
78                                        temp_input);
79         struct thermal_zone_device *tz = temp->tz;
80
81         ret = thermal_zone_get_temp(tz, &temperature);
82
83         if (ret)
84                 return ret;
85
86         return sprintf(buf, "%d\n", temperature);
87 }
88
89 static ssize_t
90 temp_crit_show(struct device *dev, struct device_attribute *attr, char *buf)
91 {
92         struct thermal_hwmon_attr *hwmon_attr
93                         = container_of(attr, struct thermal_hwmon_attr, attr);
94         struct thermal_hwmon_temp *temp
95                         = container_of(hwmon_attr, struct thermal_hwmon_temp,
96                                        temp_crit);
97         struct thermal_zone_device *tz = temp->tz;
98         int temperature;
99         int ret;
100
101         ret = tz->ops->get_crit_temp(tz, &temperature);
102         if (ret)
103                 return ret;
104
105         return sprintf(buf, "%d\n", temperature);
106 }
107
108
109 static struct thermal_hwmon_device *
110 thermal_hwmon_lookup_by_type(const struct thermal_zone_device *tz)
111 {
112         struct thermal_hwmon_device *hwmon;
113
114         mutex_lock(&thermal_hwmon_list_lock);
115         list_for_each_entry(hwmon, &thermal_hwmon_list, node)
116                 if (!strcmp(hwmon->type, tz->type)) {
117                         mutex_unlock(&thermal_hwmon_list_lock);
118                         return hwmon;
119                 }
120         mutex_unlock(&thermal_hwmon_list_lock);
121
122         return NULL;
123 }
124
125 /* Find the temperature input matching a given thermal zone */
126 static struct thermal_hwmon_temp *
127 thermal_hwmon_lookup_temp(const struct thermal_hwmon_device *hwmon,
128                           const struct thermal_zone_device *tz)
129 {
130         struct thermal_hwmon_temp *temp;
131
132         mutex_lock(&thermal_hwmon_list_lock);
133         list_for_each_entry(temp, &hwmon->tz_list, hwmon_node)
134                 if (temp->tz == tz) {
135                         mutex_unlock(&thermal_hwmon_list_lock);
136                         return temp;
137                 }
138         mutex_unlock(&thermal_hwmon_list_lock);
139
140         return NULL;
141 }
142
143 static bool thermal_zone_crit_temp_valid(struct thermal_zone_device *tz)
144 {
145         int temp;
146         return tz->ops->get_crit_temp && !tz->ops->get_crit_temp(tz, &temp);
147 }
148
149 int thermal_add_hwmon_sysfs(struct thermal_zone_device *tz)
150 {
151         struct thermal_hwmon_device *hwmon;
152         struct thermal_hwmon_temp *temp;
153         int new_hwmon_device = 1;
154         int result;
155
156         hwmon = thermal_hwmon_lookup_by_type(tz);
157         if (hwmon) {
158                 new_hwmon_device = 0;
159                 goto register_sys_interface;
160         }
161
162         hwmon = kzalloc(sizeof(*hwmon), GFP_KERNEL);
163         if (!hwmon)
164                 return -ENOMEM;
165
166         INIT_LIST_HEAD(&hwmon->tz_list);
167         strlcpy(hwmon->type, tz->type, THERMAL_NAME_LENGTH);
168         hwmon->device = hwmon_device_register(NULL);
169         if (IS_ERR(hwmon->device)) {
170                 result = PTR_ERR(hwmon->device);
171                 goto free_mem;
172         }
173         dev_set_drvdata(hwmon->device, hwmon);
174         result = device_create_file(hwmon->device, &dev_attr_name);
175         if (result)
176                 goto free_mem;
177
178  register_sys_interface:
179         temp = kzalloc(sizeof(*temp), GFP_KERNEL);
180         if (!temp) {
181                 result = -ENOMEM;
182                 goto unregister_name;
183         }
184
185         temp->tz = tz;
186         hwmon->count++;
187
188         snprintf(temp->temp_input.name, sizeof(temp->temp_input.name),
189                  "temp%d_input", hwmon->count);
190         temp->temp_input.attr.attr.name = temp->temp_input.name;
191         temp->temp_input.attr.attr.mode = 0444;
192         temp->temp_input.attr.show = temp_input_show;
193         sysfs_attr_init(&temp->temp_input.attr.attr);
194         result = device_create_file(hwmon->device, &temp->temp_input.attr);
195         if (result)
196                 goto free_temp_mem;
197
198         if (thermal_zone_crit_temp_valid(tz)) {
199                 snprintf(temp->temp_crit.name,
200                                 sizeof(temp->temp_crit.name),
201                                 "temp%d_crit", hwmon->count);
202                 temp->temp_crit.attr.attr.name = temp->temp_crit.name;
203                 temp->temp_crit.attr.attr.mode = 0444;
204                 temp->temp_crit.attr.show = temp_crit_show;
205                 sysfs_attr_init(&temp->temp_crit.attr.attr);
206                 result = device_create_file(hwmon->device,
207                                             &temp->temp_crit.attr);
208                 if (result)
209                         goto unregister_input;
210         }
211
212         mutex_lock(&thermal_hwmon_list_lock);
213         if (new_hwmon_device)
214                 list_add_tail(&hwmon->node, &thermal_hwmon_list);
215         list_add_tail(&temp->hwmon_node, &hwmon->tz_list);
216         mutex_unlock(&thermal_hwmon_list_lock);
217
218         return 0;
219
220  unregister_input:
221         device_remove_file(hwmon->device, &temp->temp_input.attr);
222  free_temp_mem:
223         kfree(temp);
224  unregister_name:
225         if (new_hwmon_device) {
226                 device_remove_file(hwmon->device, &dev_attr_name);
227                 hwmon_device_unregister(hwmon->device);
228         }
229  free_mem:
230         if (new_hwmon_device)
231                 kfree(hwmon);
232
233         return result;
234 }
235 EXPORT_SYMBOL_GPL(thermal_add_hwmon_sysfs);
236
237 void thermal_remove_hwmon_sysfs(struct thermal_zone_device *tz)
238 {
239         struct thermal_hwmon_device *hwmon;
240         struct thermal_hwmon_temp *temp;
241
242         hwmon = thermal_hwmon_lookup_by_type(tz);
243         if (unlikely(!hwmon)) {
244                 /* Should never happen... */
245                 dev_dbg(&tz->device, "hwmon device lookup failed!\n");
246                 return;
247         }
248
249         temp = thermal_hwmon_lookup_temp(hwmon, tz);
250         if (unlikely(!temp)) {
251                 /* Should never happen... */
252                 dev_dbg(&tz->device, "temperature input lookup failed!\n");
253                 return;
254         }
255
256         device_remove_file(hwmon->device, &temp->temp_input.attr);
257         if (thermal_zone_crit_temp_valid(tz))
258                 device_remove_file(hwmon->device, &temp->temp_crit.attr);
259
260         mutex_lock(&thermal_hwmon_list_lock);
261         list_del(&temp->hwmon_node);
262         kfree(temp);
263         if (!list_empty(&hwmon->tz_list)) {
264                 mutex_unlock(&thermal_hwmon_list_lock);
265                 return;
266         }
267         list_del(&hwmon->node);
268         mutex_unlock(&thermal_hwmon_list_lock);
269
270         device_remove_file(hwmon->device, &dev_attr_name);
271         hwmon_device_unregister(hwmon->device);
272         kfree(hwmon);
273 }
274 EXPORT_SYMBOL_GPL(thermal_remove_hwmon_sysfs);