power_supply_core.c revision a9b12619f7b6f19c871437ec24a088787a04b1de 
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
21struct class *power_supply_class;
22
23static 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
37static 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, NULL, psy,
45			      __power_supply_changed_work);
46
47	power_supply_update_leds(psy);
48
49	kobject_uevent(&psy->dev->kobj, KOBJ_CHANGE);
50}
51
52void 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
59static 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
78int power_supply_am_i_supplied(struct power_supply *psy)
79{
80	int error;
81
82	error = class_for_each_device(power_supply_class, NULL, psy,
83				      __power_supply_am_i_supplied);
84
85	dev_dbg(psy->dev, "%s %d\n", __func__, error);
86
87	return error;
88}
89
90int 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, psy,
95				 "%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
115create_triggers_failed:
116	power_supply_remove_attrs(psy);
117create_attrs_failed:
118	device_unregister(psy->dev);
119dev_create_failed:
120success:
121	return rc;
122}
123
124void 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
132static 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
144static void __exit power_supply_class_exit(void)
145{
146	class_destroy(power_supply_class);
147}
148
149EXPORT_SYMBOL_GPL(power_supply_changed);
150EXPORT_SYMBOL_GPL(power_supply_am_i_supplied);
151EXPORT_SYMBOL_GPL(power_supply_register);
152EXPORT_SYMBOL_GPL(power_supply_unregister);
153
154/* exported for the APM Power driver, APM emulation */
155EXPORT_SYMBOL_GPL(power_supply_class);
156
157subsys_initcall(power_supply_class_init);
158module_exit(power_supply_class_exit);
159
160MODULE_DESCRIPTION("Universal power supply monitor class");
161MODULE_AUTHOR("Ian Molton <spyro@f2s.com>, "
162	      "Szabolcs Gyurko, "
163	      "Anton Vorontsov <cbou@mail.ru>");
164MODULE_LICENSE("GPL");
165