af1633eb3b707c9c53c50e578f0ed5859ee69d96
[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 int __power_supply_changed_work(struct device *dev, void *data)
24 {
25         struct power_supply *psy = (struct power_supply *)data;
26         struct power_supply *pst = dev_get_drvdata(dev);
27         int i;
28
29         for (i = 0; i < psy->num_supplicants; i++)
30                 if (!strcmp(psy->supplied_to[i], pst->name)) {
31                         if (pst->external_power_changed)
32                                 pst->external_power_changed(pst);
33                 }
34         return 0;
35 }
36
37 static void power_supply_changed_work(struct work_struct *work)
38 {
39         struct power_supply *psy = container_of(work, struct power_supply,
40                                                 changed_work);
41
42         dev_dbg(psy->dev, "%s\n", __func__);
43
44         class_for_each_device(power_supply_class, psy,
45                               __power_supply_changed_work);
46
47         power_supply_update_leds(psy);
48
49         kobject_uevent(&psy->dev->kobj, KOBJ_CHANGE);
50 }
51
52 void power_supply_changed(struct power_supply *psy)
53 {
54         dev_dbg(psy->dev, "%s\n", __func__);
55
56         schedule_work(&psy->changed_work);
57 }
58
59 static int __power_supply_am_i_supplied(struct device *dev, void *data)
60 {
61         union power_supply_propval ret = {0,};
62         struct power_supply *psy = (struct power_supply *)data;
63         struct power_supply *epsy = dev_get_drvdata(dev);
64         int i;
65
66         for (i = 0; i < epsy->num_supplicants; i++) {
67                 if (!strcmp(epsy->supplied_to[i], psy->name)) {
68                         if (epsy->get_property(epsy,
69                                   POWER_SUPPLY_PROP_ONLINE, &ret))
70                                 continue;
71                         if (ret.intval)
72                                 return ret.intval;
73                 }
74         }
75         return 0;
76 }
77
78 int power_supply_am_i_supplied(struct power_supply *psy)
79 {
80         int error;
81
82         error = class_for_each_device(power_supply_class, psy,
83                                       __power_supply_am_i_supplied);
84
85         dev_dbg(psy->dev, "%s %d\n", __func__, error);
86
87         return error;
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_drvdata(power_supply_class, parent, 0,
95                                          psy, "%s", psy->name);
96         if (IS_ERR(psy->dev)) {
97                 rc = PTR_ERR(psy->dev);
98                 goto dev_create_failed;
99         }
100
101         INIT_WORK(&psy->changed_work, power_supply_changed_work);
102
103         rc = power_supply_create_attrs(psy);
104         if (rc)
105                 goto create_attrs_failed;
106
107         rc = power_supply_create_triggers(psy);
108         if (rc)
109                 goto create_triggers_failed;
110
111         power_supply_changed(psy);
112
113         goto success;
114
115 create_triggers_failed:
116         power_supply_remove_attrs(psy);
117 create_attrs_failed:
118         device_unregister(psy->dev);
119 dev_create_failed:
120 success:
121         return rc;
122 }
123
124 void power_supply_unregister(struct power_supply *psy)
125 {
126         flush_scheduled_work();
127         power_supply_remove_triggers(psy);
128         power_supply_remove_attrs(psy);
129         device_unregister(psy->dev);
130 }
131
132 static int __init power_supply_class_init(void)
133 {
134         power_supply_class = class_create(THIS_MODULE, "power_supply");
135
136         if (IS_ERR(power_supply_class))
137                 return PTR_ERR(power_supply_class);
138
139         power_supply_class->dev_uevent = power_supply_uevent;
140
141         return 0;
142 }
143
144 static void __exit power_supply_class_exit(void)
145 {
146         class_destroy(power_supply_class);
147 }
148
149 EXPORT_SYMBOL_GPL(power_supply_changed);
150 EXPORT_SYMBOL_GPL(power_supply_am_i_supplied);
151 EXPORT_SYMBOL_GPL(power_supply_register);
152 EXPORT_SYMBOL_GPL(power_supply_unregister);
153
154 /* exported for the APM Power driver, APM emulation */
155 EXPORT_SYMBOL_GPL(power_supply_class);
156
157 subsys_initcall(power_supply_class_init);
158 module_exit(power_supply_class_exit);
159
160 MODULE_DESCRIPTION("Universal power supply monitor class");
161 MODULE_AUTHOR("Ian Molton <spyro@f2s.com>, "
162               "Szabolcs Gyurko, "
163               "Anton Vorontsov <cbou@mail.ru>");
164 MODULE_LICENSE("GPL");