[PATCH 1/3] power: core: Add generic interface to get battery specification.

[Jonghwa Lee <jonghwa3.lee@samsung.com>]

In power supply system, battery specification's dealt as static
information regardless of battery chainging. And it often assumed
fuelgauge's role to hold battery specification even same driver is
used with different batteries. To make subsystem handles above cases
properly, this patch adds helper functions to manager the battery
specification.

Signed-off-by: Jonghwa Lee <jonghwa3.lee@samsung.com>
---
 drivers/power/power_supply_core.c |   91 +++++++++++++++++++++++++++++++++++++
 include/linux/power_supply.h      |    7 +++
 2 files changed, 98 insertions(+)

diff --git a/drivers/power/power_supply_core.c b/drivers/power/power_supply_core.c
index 078afd6..59207d9 100644
--- a/drivers/power/power_supply_core.c
+++ b/drivers/power/power_supply_core.c
@@ -653,6 +653,97 @@ static void __exit power_supply_class_exit(void)
 subsys_initcall(power_supply_class_init);
 module_exit(power_supply_class_exit);
 
+/****************************************************************
+ *                   Battery information interface              *
+ ****************************************************************/
+
+ATOMIC_NOTIFIER_HEAD(psy_battery_info_notifier);
+static LIST_HEAD(psy_battery_info_list);
+
+struct psy_battery_info {
+	struct list_head entry;
+	struct power_supply_info *info;
+};
+
+enum battery_info_notifier_events {
+	PSY_BATT_INFO_REGISTERED,
+	PSY_BATT_INFO_UNREGISTERED,
+};
+
+int psy_battery_info_notifier_register(struct notifier_block *nb)
+{
+	return atomic_notifier_chain_register(&psy_battery_info_notifier, nb);
+}
+EXPORT_SYMBOL_GPL(psy_battery_info_notifier_register);
+
+void psy_battery_info_notifier_unregister(struct notifier_block *nb)
+{
+	atomic_notifier_chain_unregister(&psy_battery_info_notifier, nb);
+}
+EXPORT_SYMBOL_GPL(psy_battery_info_notifier_unregister);
+
+struct power_supply_info *psy_get_battery_info(const char *name)
+{
+	struct psy_battery_info *battery;
+
+	/* Sanity check */
+	if (!name)
+		goto err_out;
+
+	list_for_each_entry(battery, &psy_battery_info_list, entry) {
+		if (!strcmp(battery->info->name, name))
+			return battery->info;
+	}
+
+err_out:
+	return NULL;
+}
+EXPORT_SYMBOL(psy_get_battery_info);
+
+int psy_register_battery_info(struct power_supply_info *info)
+{
+	struct psy_battery_info *battery;
+
+	/* Sanity check */
+	if (!info->name)
+		return -EINVAL;
+
+	/* Check if same data is existed */
+	list_for_each_entry(battery, &psy_battery_info_list, entry)
+		if (!strcmp(battery->info->name, info->name))
+			return -EEXIST;
+
+	battery = kzalloc(sizeof(*battery), GFP_KERNEL);
+	if (!battery)
+		return -ENOMEM;
+
+	battery->info = info;
+	list_add_tail(&battery->entry, &psy_battery_info_list);
+
+	atomic_notifier_call_chain(&psy_battery_info_notifier,
+				PSY_BATT_INFO_REGISTERED, info);
+
+	return 0;
+}
+EXPORT_SYMBOL(psy_register_battery_info);
+
+void psy_unregister_battery_info(struct power_supply_info *info)
+{
+	struct psy_battery_info *battery, *tmp;
+
+	list_for_each_entry_safe(battery, tmp, &psy_battery_info_list, entry) {
+		if (battery->info == info) {
+			list_del(&battery->entry);
+			kfree(battery);
+			return;
+		}
+	}
+
+	atomic_notifier_call_chain(&psy_battery_info_notifier,
+				PSY_BATT_INFO_UNREGISTERED, info);
+}
+EXPORT_SYMBOL(psy_unregister_battery_info);
+
 MODULE_DESCRIPTION("Universal power supply monitor class");
 MODULE_AUTHOR("Ian Molton <spyro@f2s.com>, "
 	      "Szabolcs Gyurko, "
diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
index f3dea41..99306aa 100644
--- a/include/linux/power_supply.h
+++ b/include/linux/power_supply.h
@@ -276,6 +276,13 @@ extern int power_supply_powers(struct power_supply *psy, struct device *dev);
 /* For APM emulation, think legacy userspace. */
 extern struct class *power_supply_class;
 
+/* Battery information helper */
+extern int psy_battery_info_notifier_register(struct notifier_block *);
+extern void psy_battery_info_notifier_unregister(struct notifier_block *);
+extern struct power_supply_info *psy_get_battery_info(const char *);
+extern int psy_register_battery_info(struct power_supply_info *);
+extern void psy_unregister_battery_info(struct power_supply_info *);
+
 static inline bool power_supply_is_amp_property(enum power_supply_property psp)
 {
 	switch (psp) {
-- 
1.7.9.5