e87ea515675568dc7e67aa7fb0eb2310cbe9916c
[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/device.h>
17 #include <linux/err.h>
18 #include <linux/power_supply.h>
19 #include "power_supply.h"
20
21 struct class *power_supply_class;
22
23 static void power_supply_changed_work(struct work_struct *work)
24 {
25         struct power_supply *psy = container_of(work, struct power_supply,
26                                                 changed_work);
27         int i;
28
29         dev_dbg(psy->dev, "%s\n", __FUNCTION__);
30
31         for (i = 0; i < psy->num_supplicants; i++) {
32                 struct device *dev;
33
34                 down(&power_supply_class->sem);
35                 list_for_each_entry(dev, &power_supply_class->devices, node) {
36                         struct power_supply *pst = dev_get_drvdata(dev);
37
38                         if (!strcmp(psy->supplied_to[i], pst->name)) {
39                                 if (pst->external_power_changed)
40                                         pst->external_power_changed(pst);
41                         }
42                 }
43                 up(&power_supply_class->sem);
44         }
45
46         power_supply_update_leds(psy);
47
48         kobject_uevent(&psy->dev->kobj, KOBJ_CHANGE);
49
50         return;
51 }
52
53 void power_supply_changed(struct power_supply *psy)
54 {
55         dev_dbg(psy->dev, "%s\n", __FUNCTION__);
56
57         schedule_work(&psy->changed_work);
58
59         return;
60 }
61
62 int power_supply_am_i_supplied(struct power_supply *psy)
63 {
64         union power_supply_propval ret = {0,};
65         struct device *dev;
66
67         down(&power_supply_class->sem);
68         list_for_each_entry(dev, &power_supply_class->devices, node) {
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                                         goto out;
79                         }
80                 }
81         }
82 out:
83         up(&power_supply_class->sem);
84
85         dev_dbg(psy->dev, "%s %d\n", __FUNCTION__, ret.intval);
86
87         return ret.intval;
88 }
89
90 int power_supply_register(struct device *parent, struct power_supply *psy)
91 {
92         int rc = 0;
93
94         psy->dev = device_create(power_supply_class, parent, 0,
95                                  "%s", psy->name);
96         if (IS_ERR(psy->dev)) {
97                 rc = PTR_ERR(psy->dev);
98                 goto dev_create_failed;
99         }
100
101         dev_set_drvdata(psy->dev, psy);
102
103         INIT_WORK(&psy->changed_work, power_supply_changed_work);
104
105         rc = power_supply_create_attrs(psy);
106         if (rc)
107                 goto create_attrs_failed;
108
109         rc = power_supply_create_triggers(psy);
110         if (rc)
111                 goto create_triggers_failed;
112
113         power_supply_changed(psy);
114
115         goto success;
116
117 create_triggers_failed:
118         power_supply_remove_attrs(psy);
119 create_attrs_failed:
120         device_unregister(psy->dev);
121 dev_create_failed:
122 success:
123         return rc;
124 }
125
126 void power_supply_unregister(struct power_supply *psy)
127 {
128         flush_scheduled_work();
129         power_supply_remove_triggers(psy);
130         power_supply_remove_attrs(psy);
131         device_unregister(psy->dev);
132         return;
133 }
134
135 static int __init power_supply_class_init(void)
136 {
137         power_supply_class = class_create(THIS_MODULE, "power_supply");
138
139         if (IS_ERR(power_supply_class))
140                 return PTR_ERR(power_supply_class);
141
142         power_supply_class->dev_uevent = power_supply_uevent;
143
144         return 0;
145 }
146
147 static void __exit power_supply_class_exit(void)
148 {
149         class_destroy(power_supply_class);
150         return;
151 }
152
153 EXPORT_SYMBOL_GPL(power_supply_changed);
154 EXPORT_SYMBOL_GPL(power_supply_am_i_supplied);
155 EXPORT_SYMBOL_GPL(power_supply_register);
156 EXPORT_SYMBOL_GPL(power_supply_unregister);
157
158 /* exported for the APM Power driver, APM emulation */
159 EXPORT_SYMBOL_GPL(power_supply_class);
160
161 subsys_initcall(power_supply_class_init);
162 module_exit(power_supply_class_exit);
163
164 MODULE_DESCRIPTION("Universal power supply monitor class");
165 MODULE_AUTHOR("Ian Molton <spyro@f2s.com>, "
166               "Szabolcs Gyurko, "
167               "Anton Vorontsov <cbou@mail.ru>");
168 MODULE_LICENSE("GPL");