power: supply: bq27xxx: Move cycle count reading out of update loop

Most of the functions that read values return a status and put the value
itself in an a function parameter. Update cycle count reading to match.

As cycle count is not checked for changes as part of the update loop,
remove the read of this from the periodic update loop. This saves I2C/1W
bandwidth. It also means we do not have to cache it, fresh values are
read when requested.

Signed-off-by: Andrew Davis <afd@ti.com>
Link: https://lore.kernel.org/r/20240325203129.150030-5-afd@ti.com
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

Author: glneo

drivers/power/supply/bq27xxx_battery.c

@@ -1690,15 +1690,18 @@ static int bq27xxx_battery_read_temperature(struct bq27xxx_device_info *di,
  * Return the battery Cycle count total
  * Or < 0 if something fails.
  */
-static int bq27xxx_battery_read_cyct(struct bq27xxx_device_info *di)
+static int bq27xxx_battery_read_cyct(struct bq27xxx_device_info *di,
+				     union power_supply_propval *val)
 {
 	int cyct;
 
 	cyct = bq27xxx_read(di, BQ27XXX_REG_CYCT, false);
 	if (cyct < 0)
 		dev_err(di->dev, "error reading cycle count total\n");
 
-	return cyct;
+	val->intval = cyct;
+
+	return 0;
 }
 
 /*
@@ -1872,8 +1875,6 @@ static void bq27xxx_battery_update_unlocked(struct bq27xxx_device_info *di)
 		cache.capacity = bq27xxx_battery_read_soc(di);
 		di->cache.flags = cache.flags;
 		cache.health = bq27xxx_battery_read_health(di);
-		if (di->regs[BQ27XXX_REG_CYCT] != INVALID_REG_ADDR)
-			cache.cycle_count = bq27xxx_battery_read_cyct(di);
 
 		/*
 		 * On gauges with signed current reporting the current must be
@@ -2082,7 +2083,7 @@ static int bq27xxx_battery_get_property(struct power_supply *psy,
 	case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
 		return -EINVAL;
 	case POWER_SUPPLY_PROP_CYCLE_COUNT:
-		ret = bq27xxx_simple_value(di->cache.cycle_count, val);
+		ret = bq27xxx_battery_read_cyct(di, val);
 		break;
 	case POWER_SUPPLY_PROP_ENERGY_NOW:
 		ret = bq27xxx_battery_read_energy(di, val);

include/linux/power/bq27xxx_battery.h

@@ -47,7 +47,6 @@ struct bq27xxx_access_methods {
 };
 
 struct bq27xxx_reg_cache {
-	int cycle_count;
 	int capacity;
 	int flags;
 	int health;