power: supply: axp20x_battery: Fix fault handling for AXP717

Correct the fault handling for the AXP717 by changing the i2c write
from regmap_update_bits() to regmap_write_bits(). The update bits
function does not work properly on a RW1C register where we must
write a 1 back to an existing register to clear it.

Additionally, as part of this testing I confirmed the behavior of
errors reappearing, so remove comment about assumptions.

Fixes: 6625767 ("power: supply: axp20x_battery: add support for AXP717")
Signed-off-by: Chris Morgan <macromorgan@hotmail.com>
Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Link: https://lore.kernel.org/r/20250131231455.153447-2-macroalpha82@gmail.com
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

Author: macromorgan

drivers/power/supply/axp20x_battery.c

@@ -466,10 +466,9 @@ static int axp717_battery_get_prop(struct power_supply *psy,
 
 	/*
 	 * If a fault is detected it must also be cleared; if the
-	 * condition persists it should reappear (This is an
-	 * assumption, it's actually not documented). A restart was
-	 * not sufficient to clear the bit in testing despite the
-	 * register listed as POR.
+	 * condition persists it should reappear. A restart was not
+	 * sufficient to clear the bit in testing despite the register
+	 * listed as POR.
 	 */
 	case POWER_SUPPLY_PROP_HEALTH:
 		ret = regmap_read(axp20x_batt->regmap, AXP717_PMU_FAULT,
@@ -480,26 +479,26 @@ static int axp717_battery_get_prop(struct power_supply *psy,
 		switch (reg & AXP717_BATT_PMU_FAULT_MASK) {
 		case AXP717_BATT_UVLO_2_5V:
 			val->intval = POWER_SUPPLY_HEALTH_DEAD;
-			regmap_update_bits(axp20x_batt->regmap,
-					   AXP717_PMU_FAULT,
-					   AXP717_BATT_UVLO_2_5V,
-					   AXP717_BATT_UVLO_2_5V);
+			regmap_write_bits(axp20x_batt->regmap,
+					  AXP717_PMU_FAULT,
+					  AXP717_BATT_UVLO_2_5V,
+					  AXP717_BATT_UVLO_2_5V);
 			return 0;
 
 		case AXP717_BATT_OVER_TEMP:
 			val->intval = POWER_SUPPLY_HEALTH_HOT;
-			regmap_update_bits(axp20x_batt->regmap,
-					   AXP717_PMU_FAULT,
-					   AXP717_BATT_OVER_TEMP,
-					   AXP717_BATT_OVER_TEMP);
+			regmap_write_bits(axp20x_batt->regmap,
+					  AXP717_PMU_FAULT,
+					  AXP717_BATT_OVER_TEMP,
+					  AXP717_BATT_OVER_TEMP);
 			return 0;
 
 		case AXP717_BATT_UNDER_TEMP:
 			val->intval = POWER_SUPPLY_HEALTH_COLD;
-			regmap_update_bits(axp20x_batt->regmap,
-					   AXP717_PMU_FAULT,
-					   AXP717_BATT_UNDER_TEMP,
-					   AXP717_BATT_UNDER_TEMP);
+			regmap_write_bits(axp20x_batt->regmap,
+					  AXP717_PMU_FAULT,
+					  AXP717_BATT_UNDER_TEMP,
+					  AXP717_BATT_UNDER_TEMP);
 			return 0;
 
 		default: