[PATCH 5/5] power: supply: rk817-charger: Clear SYS_CAN_SD register by default

[Chris Morgan <macroalpha82@gmail.com>]

From: Chris Morgan <macromorgan@hotmail.com>

The BSP driver for the rk817 charger by default sets the SYS_CAN_SD
register unless a specific attribute is set in the device tree. This
register tells the PMIC that the system voltage can be shut down in
battery off mode.

Though the BSP sets this value by default, it also has a device tree
value to override it.

When this value is not set, it can result in a persistent power
drain while the device is off, as observed by users.

Fixes: 11cb8da0189b ("power: supply: Add charger driver for Rockchip RK817")
Signed-off-by: Chris Morgan <macromorgan@hotmail.com>
Suggested-by: Zetarancio <zetarancio@users.noreply.github.com>
---
 drivers/power/supply/rk817_charger.c | 9 +++++++++
 include/linux/mfd/rk808.h            | 1 +
 2 files changed, 10 insertions(+)

diff --git a/drivers/power/supply/rk817_charger.c b/drivers/power/supply/rk817_charger.c
index b6714d8e4fed..6971f572c68d 100644
--- a/drivers/power/supply/rk817_charger.c
+++ b/drivers/power/supply/rk817_charger.c
@@ -1148,6 +1148,15 @@ static int rk817_battery_init(struct rk817_charger *charger,
 	regmap_write_bits(rk808->regmap, RK817_PMIC_CHRG_IN, RK817_USB_ILIM_EN,
 			  (0x01 << 3));
 
+	/*
+	 * Shutdown the system voltage in bat_off mode, unless
+	 * gate-function-disable is set.
+	 */
+	if (!device_property_read_bool(charger->dev,
+				       "rockchip,gate-function-disable"))
+		regmap_clear_bits(rk808->regmap,
+				  RK817_PMIC_CHRG_TERM, RK817_SYS_CAN_SD);
+
 	return 0;
 }
 
diff --git a/include/linux/mfd/rk808.h b/include/linux/mfd/rk808.h
index 72419d311626..2bc58de53d82 100644
--- a/include/linux/mfd/rk808.h
+++ b/include/linux/mfd/rk808.h
@@ -1297,6 +1297,7 @@ enum rk809_reg_id {
 #define RK817_USB_ILIM_EN		(0x01 << 3)
 #define RK817_USB_ILIM_SEL		(0x07 << 0)
 #define RK817_PMIC_CHRG_TERM		0xe6
+#define RK817_SYS_CAN_SD		(0x01 << 7)
 #define RK817_CHRG_TERM_ANA_DIG		(0x01 << 2)
 #define RK817_CHRG_TERM_ANA_SEL		(0x03 << 0)
 #define RK817_CHRG_EN			(0x01 << 6)
-- 
2.53.0