[PATCH v2] arm64: dts: meson: switch TFLASH_VDD_EN pin to open drain on Odroid-C4

[PATCH v2] 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 of the
ACTIVE_HIGH, what will leave the pin in input mode to achieve high state
(pin has the pull-up) and solve the issue.

Suggested-by: Neil Armstrong <narmstrong@baylibre.com>
Fixes: 326e57518b0d ("arm64: dts: meson-sm1: add support for Hardkernel ODROID-C4")
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Martin Blumenstingl <martin.blumenstingl@googlemail.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

Changelog:
v2:
- fixed typo in the commit message

v1: https://lore.kernel.org/linux-amlogic/20201218102228.16211-1-m.szyprowski@samsung.com/
- initial version
---
 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


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Re: [PATCH v2] arm64: dts: meson: switch TFLASH_VDD_EN pin to open drain on Odroid-C4

[Neil Armstrong]

On 22/01/2021 06:52, Marek Szyprowski wrote:
> 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 of the
> ACTIVE_HIGH, what will leave the pin in input mode to achieve high state
> (pin has the pull-up) and solve the issue.
> 
> Suggested-by: Neil Armstrong <narmstrong@baylibre.com>
> Fixes: 326e57518b0d ("arm64: dts: meson-sm1: add support for Hardkernel ODROID-C4")
> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
> Acked-by: Martin Blumenstingl <martin.blumenstingl@googlemail.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
> 
> Changelog:
> v2:
> - fixed typo in the commit message
> 
> v1: https://lore.kernel.org/linux-amlogic/20201218102228.16211-1-m.szyprowski@samsung.com/
> - initial version
> ---
>  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;
>  	};
> 

Hi Kevin,

The same fix was pushed on u-boot and solves the issue.

Could you take it for fixes ?

Acked-by: Neil Armstrong <narmstrong@baylibre.com>

Neil

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Re: [PATCH v2] arm64: dts: meson: switch TFLASH_VDD_EN pin to open drain on Odroid-C4

[Kevin Hilman]

On Fri, 22 Jan 2021 06:52:18 +0100, Marek Szyprowski wrote:
> 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 of the
> ACTIVE_HIGH, what will leave the pin in input mode to achieve high state
> (pin has the pull-up) and solve the issue.

Applied, thanks!

[1/1] arm64: dts: meson: switch TFLASH_VDD_EN pin to open drain on Odroid-C4
      commit: c649d91a8ec4dda78bcbd3890156bffb4df2fa16

Best regards,
-- 
Kevin Hilman <khilman@baylibre.com>

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