power: supply: core: Add power_supply_battery_info and API

power_supply_get_battery_info() reads battery data from devicetree.
struct power_supply_battery_info provides battery data to drivers.
Its fields correspond to elements in enum power_supply_property.
Drivers may surface battery data in sysfs via corresponding
POWER_SUPPLY_PROP_* fields.

Signed-off-by: Matt Ranostay <matt@ranostay.consulting>
Signed-off-by: Liam Breck <kernel@networkimprov.net>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
index 4bd3405..34345d7 100644
--- a/include/linux/power_supply.h
+++ b/include/linux/power_supply.h
@@ -289,6 +289,25 @@ struct power_supply_info {
 	int use_for_apm;
 };
 
+/*
+ * This is the recommended struct to manage static battery parameters,
+ * populated by power_supply_get_battery_info(). Most platform drivers should
+ * use these for consistency.
+ * Its field names must correspond to elements in enum power_supply_property.
+ * The default field value is -EINVAL.
+ * Power supply class itself doesn't use this.
+ */
+
+struct power_supply_battery_info {
+	int energy_full_design_uwh;	    /* microWatt-hours */
+	int charge_full_design_uah;	    /* microAmp-hours */
+	int voltage_min_design_uv;	    /* microVolts */
+	int precharge_current_ua;	    /* microAmps */
+	int charge_term_current_ua;	    /* microAmps */
+	int constant_charge_current_max_ua; /* microAmps */
+	int constant_charge_voltage_max_uv; /* microVolts */
+};
+
 extern struct atomic_notifier_head power_supply_notifier;
 extern int power_supply_reg_notifier(struct notifier_block *nb);
 extern void power_supply_unreg_notifier(struct notifier_block *nb);
@@ -307,6 +326,9 @@ static inline struct power_supply *
 devm_power_supply_get_by_phandle(struct device *dev, const char *property)
 { return NULL; }
 #endif /* CONFIG_OF */
+
+extern int power_supply_get_battery_info(struct power_supply *psy,
+					 struct power_supply_battery_info *info);
 extern void power_supply_changed(struct power_supply *psy);
 extern int power_supply_am_i_supplied(struct power_supply *psy);
 extern int power_supply_set_battery_charged(struct power_supply *psy);