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 */
 23struct class *power_supply_class;
 24EXPORT_SYMBOL_GPL(power_supply_class);
 25
 26static struct device_type power_supply_dev_type;
 27
 28static 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
 42static 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
 57void power_supply_changed(struct power_supply *psy)
 58{
 59	dev_dbg(psy->dev, "%s\n", __func__);
 60
 61	schedule_work(&psy->changed_work);
 62}
 63EXPORT_SYMBOL_GPL(power_supply_changed);
 64
 65static 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
 84int 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}
 95EXPORT_SYMBOL_GPL(power_supply_am_i_supplied);
 96
 97static 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
111int 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}
120EXPORT_SYMBOL_GPL(power_supply_is_system_supplied);
121
122int 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}
131EXPORT_SYMBOL_GPL(power_supply_set_battery_charged);
132
133static 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
141struct 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}
148EXPORT_SYMBOL_GPL(power_supply_get_by_name);
149
150static 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
156int 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	INIT_WORK(&psy->changed_work, power_supply_changed_work);
175
176	rc = kobject_set_name(&dev->kobj, "%s", psy->name);
177	if (rc)
178		goto kobject_set_name_failed;
179
180	rc = device_add(dev);
181	if (rc)
182		goto device_add_failed;
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
192create_triggers_failed:
193	device_del(dev);
194kobject_set_name_failed:
195device_add_failed:
196	put_device(dev);
197success:
198	return rc;
199}
200EXPORT_SYMBOL_GPL(power_supply_register);
201
202void power_supply_unregister(struct power_supply *psy)
203{
204	cancel_work_sync(&psy->changed_work);
205	power_supply_remove_triggers(psy);
206	device_unregister(psy->dev);
207}
208EXPORT_SYMBOL_GPL(power_supply_unregister);
209
210static 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
223static void __exit power_supply_class_exit(void)
224{
225	class_destroy(power_supply_class);
226}
227
228subsys_initcall(power_supply_class_init);
229module_exit(power_supply_class_exit);
230
231MODULE_DESCRIPTION("Universal power supply monitor class");
232MODULE_AUTHOR("Ian Molton <spyro@f2s.com>, "
233	      "Szabolcs Gyurko, "
234	      "Anton Vorontsov <cbou@mail.ru>");
235MODULE_LICENSE("GPL");