power: supply: bq27xxx: Move time 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 time reading to match.

As time is not checked for changes as part of the update loop, remove
the read of the 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/20240325203129.150030-2-afd@ti.com
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

Author: glneo

drivers/power/supply/bq27xxx_battery.c

@@ -1696,7 +1696,8 @@ static int bq27xxx_battery_read_cyct(struct bq27xxx_device_info *di)
  * Read a time register.
  * Return < 0 if something fails.
  */
-static int bq27xxx_battery_read_time(struct bq27xxx_device_info *di, u8 reg)
+static int bq27xxx_battery_read_time(struct bq27xxx_device_info *di, u8 reg,
+				     union power_supply_propval *val)
 {
 	int tval;
 
@@ -1710,7 +1711,9 @@ static int bq27xxx_battery_read_time(struct bq27xxx_device_info *di, u8 reg)
 	if (tval == 65535)
 		return -ENODATA;
 
-	return tval * 60;
+	val->intval = tval * 60;
+
+	return 0;
 }
 
 /*
@@ -1857,13 +1860,6 @@ static void bq27xxx_battery_update_unlocked(struct bq27xxx_device_info *di)
 	if ((cache.flags & 0xff) == 0xff)
 		cache.flags = -1; /* read error */
 	if (cache.flags >= 0) {
-		if (di->regs[BQ27XXX_REG_TTE] != INVALID_REG_ADDR)
-			cache.time_to_empty = bq27xxx_battery_read_time(di, BQ27XXX_REG_TTE);
-		if (di->regs[BQ27XXX_REG_TTECP] != INVALID_REG_ADDR)
-			cache.time_to_empty_avg = bq27xxx_battery_read_time(di, BQ27XXX_REG_TTECP);
-		if (di->regs[BQ27XXX_REG_TTF] != INVALID_REG_ADDR)
-			cache.time_to_full = bq27xxx_battery_read_time(di, BQ27XXX_REG_TTF);
-
 		cache.charge_full = bq27xxx_battery_read_fcc(di);
 		cache.capacity = bq27xxx_battery_read_soc(di);
 		if (di->regs[BQ27XXX_REG_AE] != INVALID_REG_ADDR)
@@ -2046,13 +2042,13 @@ static int bq27xxx_battery_get_property(struct power_supply *psy,
 		ret = bq27xxx_battery_read_temperature(di, val);
 		break;
 	case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW:
-		ret = bq27xxx_simple_value(di->cache.time_to_empty, val);
+		ret = bq27xxx_battery_read_time(di, BQ27XXX_REG_TTE, val);
 		break;
 	case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
-		ret = bq27xxx_simple_value(di->cache.time_to_empty_avg, val);
+		ret = bq27xxx_battery_read_time(di, BQ27XXX_REG_TTECP, val);
 		break;
 	case POWER_SUPPLY_PROP_TIME_TO_FULL_NOW:
-		ret = bq27xxx_simple_value(di->cache.time_to_full, val);
+		ret = bq27xxx_battery_read_time(di, BQ27XXX_REG_TTF, val);
 		break;
 	case POWER_SUPPLY_PROP_TECHNOLOGY:
 		if (di->opts & BQ27XXX_O_MUL_CHEM)

include/linux/power/bq27xxx_battery.h

@@ -47,9 +47,6 @@ struct bq27xxx_access_methods {
 };
 
 struct bq27xxx_reg_cache {
-	int time_to_empty;
-	int time_to_empty_avg;
-	int time_to_full;
 	int charge_full;
 	int cycle_count;
 	int capacity;