power_supply: Fix use after free and memory leak
[linux-2.6.git] / drivers / power / power_supply_core.c
1 /*
2  *  Universal power supply monitor class
3  *
4  *  Copyright © 2007  Anton Vorontsov <cbou@mail.ru>
5  *  Copyright © 2004  Szabolcs Gyurko
6  *  Copyright © 2003  Ian Molton <spyro@f2s.com>
7  *
8  *  Modified: 2004, Oct     Szabolcs Gyurko
9  *
10  *  You may use this code as per GPL version 2
11  */
12
13 #include <linux/module.h>
14 #include <linux/types.h>
15 #include <linux/init.h>
16 #include <linux/slab.h>
17 #include <linux/device.h>
18 #include <linux/err.h>
19 #include <linux/power_supply.h>
20 #include "power_supply.h"
21
22 /* exported for the APM Power driver, APM emulation */
23 struct class *power_supply_class;
24 EXPORT_SYMBOL_GPL(power_supply_class);
25
26 static struct device_type power_supply_dev_type;
27
28 static int __power_supply_changed_work(struct device *dev, void *data)
29 {
30         struct power_supply *psy = (struct power_supply *)data;
31         struct power_supply *pst = dev_get_drvdata(dev);
32         int i;
33
34         for (i = 0; i < psy->num_supplicants; i++)
35                 if (!strcmp(psy->supplied_to[i], pst->name)) {
36                         if (pst->external_power_changed)
37                                 pst->external_power_changed(pst);
38                 }
39         return 0;
40 }
41
42 static void power_supply_changed_work(struct work_struct *work)
43 {
44         struct power_supply *psy = container_of(work, struct power_supply,
45                                                 changed_work);
46
47         dev_dbg(psy->dev, "%s\n", __func__);
48
49         class_for_each_device(power_supply_class, NULL, psy,
50                               __power_supply_changed_work);
51
52         power_supply_update_leds(psy);
53
54         kobject_uevent(&psy->dev->kobj, KOBJ_CHANGE);
55 }
56
57 void power_supply_changed(struct power_supply *psy)
58 {
59         dev_dbg(psy->dev, "%s\n", __func__);
60
61         schedule_work(&psy->changed_work);
62 }
63 EXPORT_SYMBOL_GPL(power_supply_changed);
64
65 static int __power_supply_am_i_supplied(struct device *dev, void *data)
66 {
67         union power_supply_propval ret = {0,};
68         struct power_supply *psy = (struct power_supply *)data;
69         struct power_supply *epsy = dev_get_drvdata(dev);
70         int i;
71
72         for (i = 0; i < epsy->num_supplicants; i++) {
73                 if (!strcmp(epsy->supplied_to[i], psy->name)) {
74                         if (epsy->get_property(epsy,
75                                   POWER_SUPPLY_PROP_ONLINE, &ret))
76                                 continue;
77                         if (ret.intval)
78                                 return ret.intval;
79                 }
80         }
81         return 0;
82 }
83
84 int power_supply_am_i_supplied(struct power_supply *psy)
85 {
86         int error;
87
88         error = class_for_each_device(power_supply_class, NULL, psy,
89                                       __power_supply_am_i_supplied);
90
91         dev_dbg(psy->dev, "%s %d\n", __func__, error);
92
93         return error;
94 }
95 EXPORT_SYMBOL_GPL(power_supply_am_i_supplied);
96
97 static int __power_supply_is_system_supplied(struct device *dev, void *data)
98 {
99         union power_supply_propval ret = {0,};
100         struct power_supply *psy = dev_get_drvdata(dev);
101
102         if (psy->type != POWER_SUPPLY_TYPE_BATTERY) {
103                 if (psy->get_property(psy, POWER_SUPPLY_PROP_ONLINE, &ret))
104                         return 0;
105                 if (ret.intval)
106                         return ret.intval;
107         }
108         return 0;
109 }
110
111 int power_supply_is_system_supplied(void)
112 {
113         int error;
114
115         error = class_for_each_device(power_supply_class, NULL, NULL,
116                                       __power_supply_is_system_supplied);
117
118         return error;
119 }
120 EXPORT_SYMBOL_GPL(power_supply_is_system_supplied);
121
122 int power_supply_set_battery_charged(struct power_supply *psy)
123 {
124         if (psy->type == POWER_SUPPLY_TYPE_BATTERY && psy->set_charged) {
125                 psy->set_charged(psy);
126                 return 0;
127         }
128
129         return -EINVAL;
130 }
131 EXPORT_SYMBOL_GPL(power_supply_set_battery_charged);
132
133 static int power_supply_match_device_by_name(struct device *dev, void *data)
134 {
135         const char *name = data;
136         struct power_supply *psy = dev_get_drvdata(dev);
137
138         return strcmp(psy->name, name) == 0;
139 }
140
141 struct power_supply *power_supply_get_by_name(char *name)
142 {
143         struct device *dev = class_find_device(power_supply_class, NULL, name,
144                                         power_supply_match_device_by_name);
145
146         return dev ? dev_get_drvdata(dev) : NULL;
147 }
148 EXPORT_SYMBOL_GPL(power_supply_get_by_name);
149
150 static void power_supply_dev_release(struct device *dev)
151 {
152         pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
153         kfree(dev);
154 }
155
156 int power_supply_register(struct device *parent, struct power_supply *psy)
157 {
158         struct device *dev;
159         int rc;
160
161         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
162         if (!dev)
163                 return -ENOMEM;
164
165         device_initialize(dev);
166
167         dev->class = power_supply_class;
168         dev->type = &power_supply_dev_type;
169         dev->parent = parent;
170         dev->release = power_supply_dev_release;
171         dev_set_drvdata(dev, psy);
172         psy->dev = dev;
173
174         rc = kobject_set_name(&dev->kobj, "%s", psy->name);
175         if (rc)
176                 goto kobject_set_name_failed;
177
178         rc = device_add(dev);
179         if (rc)
180                 goto device_add_failed;
181
182         INIT_WORK(&psy->changed_work, power_supply_changed_work);
183
184         rc = power_supply_create_triggers(psy);
185         if (rc)
186                 goto create_triggers_failed;
187
188         power_supply_changed(psy);
189
190         goto success;
191
192 create_triggers_failed:
193         device_del(dev);
194 kobject_set_name_failed:
195 device_add_failed:
196         put_device(dev);
197 success:
198         return rc;
199 }
200 EXPORT_SYMBOL_GPL(power_supply_register);
201
202 void power_supply_unregister(struct power_supply *psy)
203 {
204         flush_scheduled_work();
205         power_supply_remove_triggers(psy);
206         device_unregister(psy->dev);
207 }
208 EXPORT_SYMBOL_GPL(power_supply_unregister);
209
210 static int __init power_supply_class_init(void)
211 {
212         power_supply_class = class_create(THIS_MODULE, "power_supply");
213
214         if (IS_ERR(power_supply_class))
215                 return PTR_ERR(power_supply_class);
216
217         power_supply_class->dev_uevent = power_supply_uevent;
218         power_supply_init_attrs(&power_supply_dev_type);
219
220         return 0;
221 }
222
223 static void __exit power_supply_class_exit(void)
224 {
225         class_destroy(power_supply_class);
226 }
227
228 subsys_initcall(power_supply_class_init);
229 module_exit(power_supply_class_exit);
230
231 MODULE_DESCRIPTION("Universal power supply monitor class");
232 MODULE_AUTHOR("Ian Molton <spyro@f2s.com>, "
233               "Szabolcs Gyurko, "
234               "Anton Vorontsov <cbou@mail.ru>");
235 MODULE_LICENSE("GPL");