[PATCH] arm64: dts: meson: switch TFLASH_VDD_EN pin to open drain on Odroid-C4

[Marek Szyprowski]

For the proper reboot Odroid-C4 board requires to switch TFLASH_VDD_EN
pin to the high impedance mode, otherwise the board is stuck in the
middle of loading early stages of the bootloader from SD card.

This can be achieved by using the OPEN_DRAIN flag instead if the
ACTIVE_HIGH, what will leave the pin in input to achieve high state (pin
has the pull-up) and solve the issue.

Suggested-by: Neil Armstrong <narmstrong at baylibre.com>
Fixes: 326e57518b0d ("arm64: dts: meson-sm1: add support for Hardkernel ODROID-C4")
Signed-off-by: Marek Szyprowski <m.szyprowski at samsung.com>
---
Here is a discussion on u-boot's mailing list that inspired this patch:
https://lists.denx.de/pipermail/u-boot/2020-December/435295.html
---
 arch/arm64/boot/dts/amlogic/meson-sm1-odroid-c4.dts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/amlogic/meson-sm1-odroid-c4.dts b/arch/arm64/boot/dts/amlogic/meson-sm1-odroid-c4.dts
index cf5a98f0e47c..a712273c905a 100644
--- a/arch/arm64/boot/dts/amlogic/meson-sm1-odroid-c4.dts
+++ b/arch/arm64/boot/dts/amlogic/meson-sm1-odroid-c4.dts
@@ -52,7 +52,7 @@
 		regulator-min-microvolt = <3300000>;
 		regulator-max-microvolt = <3300000>;
 
-		gpio = <&gpio_ao GPIOAO_3 GPIO_ACTIVE_HIGH>;
+		gpio = <&gpio_ao GPIOAO_3 GPIO_OPEN_DRAIN>;
 		enable-active-high;
 		regulator-always-on;
 	};
-- 
2.17.1