power: supply: bq27xxx: Add cache parameter to bq27xxx_battery_current_and_status()

Add a cache parameter to bq27xxx_battery_current_and_status() so that
it can optionally use cached flags instead of re-reading them itself.

This is a preparation patch for making bq27xxx_battery_update() check
the status and have it call power_supply_changed() on status changes.

Fixes: 297a533 ("bq27x00: Cache battery registers")
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

Author: jwrdegoede

drivers/power/supply/bq27xxx_battery.c

@@ -1840,7 +1840,8 @@ static bool bq27xxx_battery_is_full(struct bq27xxx_device_info *di, int flags)
 static int bq27xxx_battery_current_and_status(
 	struct bq27xxx_device_info *di,
 	union power_supply_propval *val_curr,
-	union power_supply_propval *val_status)
+	union power_supply_propval *val_status,
+	struct bq27xxx_reg_cache *cache)
 {
 	bool single_flags = (di->opts & BQ27XXX_O_ZERO);
 	int curr;
@@ -1852,10 +1853,14 @@ static int bq27xxx_battery_current_and_status(
 		return curr;
 	}
 
-	flags = bq27xxx_read(di, BQ27XXX_REG_FLAGS, single_flags);
-	if (flags < 0) {
-		dev_err(di->dev, "error reading flags\n");
-		return flags;
+	if (cache) {
+		flags = cache->flags;
+	} else {
+		flags = bq27xxx_read(di, BQ27XXX_REG_FLAGS, single_flags);
+		if (flags < 0) {
+			dev_err(di->dev, "error reading flags\n");
+			return flags;
+		}
 	}
 
 	if (di->opts & BQ27XXX_O_ZERO) {
@@ -2001,7 +2006,7 @@ static int bq27xxx_battery_get_property(struct power_supply *psy,
 
 	switch (psp) {
 	case POWER_SUPPLY_PROP_STATUS:
-		ret = bq27xxx_battery_current_and_status(di, NULL, val);
+		ret = bq27xxx_battery_current_and_status(di, NULL, val, NULL);
 		break;
 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 		ret = bq27xxx_battery_voltage(di, val);
@@ -2010,7 +2015,7 @@ static int bq27xxx_battery_get_property(struct power_supply *psy,
 		val->intval = di->cache.flags < 0 ? 0 : 1;
 		break;
 	case POWER_SUPPLY_PROP_CURRENT_NOW:
-		ret = bq27xxx_battery_current_and_status(di, val, NULL);
+		ret = bq27xxx_battery_current_and_status(di, val, NULL, NULL);
 		break;
 	case POWER_SUPPLY_PROP_CAPACITY:
 		ret = bq27xxx_simple_value(di->cache.capacity, val);