[RFC PATCH 3/3] arm64: dts: rockchip: fix power-off on Firefly-RK3399

[Yaozhong Li <yaozhonguwl@gmail.com>]

poweroff on this board drops the rails and immediately brings them back
up, so it reboots instead of staying off and U-Boot reports a power-on
reset.

Firefly's BSP drives GPIO1_D0 and GPIO1_B5 low during shutdown, before
writing the RK808's shutdown bit. Mainline does not describe GPIO1_D0 at
all, and describes GPIO1_B5 as the backlight enable GPIO - the vendor's
own backlight node has no enable GPIO. Nothing therefore releases either
line at power-off, and while the backlight owns GPIO1_B5 it can hold it
asserted, which is enough to make the board come back up on its own.

Describe both lines in the PMIC node and drop the backlight enable-gpios,
with the settle time the vendor uses.

Fixes: 171582e00db1 ("arm64: dts: rockchip: add support for firefly-rk3399 board")
Signed-off-by: Yaozhong Li <yaozhonguwl@gmail.com>
---
 arch/arm64/boot/dts/rockchip/rk3399-firefly.dts | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/rockchip/rk3399-firefly.dts b/arch/arm64/boot/dts/rockchip/rk3399-firefly.dts
index 0568dfa..75b75fe 100644
--- a/arch/arm64/boot/dts/rockchip/rk3399-firefly.dts
+++ b/arch/arm64/boot/dts/rockchip/rk3399-firefly.dts
@@ -27,7 +27,6 @@ chosen {
 
 	backlight: backlight {
 		compatible = "pwm-backlight";
-		enable-gpios = <&gpio1 RK_PB5 GPIO_ACTIVE_HIGH>;
 		pwms = <&pwm0 0 25000 0>;
 		brightness-levels = <
 			  0   1   2   3   4   5   6   7
@@ -327,6 +326,9 @@ rk808: pmic@1b {
 		pinctrl-names = "default";
 		pinctrl-0 = <&pmic_int_l>;
 		system-power-controller;
+		power-hold-gpios = <&gpio1 RK_PD0 GPIO_ACTIVE_HIGH>,
+				   <&gpio1 RK_PB5 GPIO_ACTIVE_HIGH>;
+		power-hold-delay-ms = <200>;
 		wakeup-source;
 
 		vcc1-supply = <&vcc_sys>;
-- 
2.55.0.windows.3