power: reset: sc27xx: Power off the external subsystems' connection

When powering off the whole system, we should power off some external
subsystems' connection firstly, otherwise some external subsystems
will hold some power and result in powering down abnormally.

Signed-off-by: Sherry Zong <sherry.zong@unisoc.com>
Signed-off-by: Baolin Wang <baolin.wang7@gmail.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

diff --git a/drivers/power/reset/sc27xx-poweroff.c b/drivers/power/reset/sc27xx-poweroff.c
index 29fb08b..2bedd4c 100644 (file)
--- a/drivers/power/reset/sc27xx-poweroff.c
+++ b/drivers/power/reset/sc27xx-poweroff.c
@@ -13,6 +13,8 @@
 
 #define SC27XX_PWR_PD_HW       0xc2c
 #define SC27XX_PWR_OFF_EN      BIT(0)
+#define SC27XX_SLP_CTRL                0xdf0
+#define SC27XX_LDO_XTL_EN      BIT(3)
 
 static struct regmap *regmap;
 
@@ -40,6 +42,9 @@ static struct syscore_ops poweroff_syscore_ops = {
 
 static void sc27xx_poweroff_do_poweroff(void)
 {
+       /* Disable the external subsys connection's power firstly */
+       regmap_write(regmap, SC27XX_SLP_CTRL, SC27XX_LDO_XTL_EN);
+
        regmap_write(regmap, SC27XX_PWR_PD_HW, SC27XX_PWR_OFF_EN);
 }