[PATCH] ARM: dts: stm32: Consistently enable internal pull-ups for SD bus

From: Patrick DELAUNAY <patrick.delaunay@foss.st.com>
To: u-boot@lists.denx.de
Subject: [PATCH] ARM: dts: stm32: Consistently enable internal pull-ups for SD bus
Date: Wed, 9 Dec 2020 11:22:12 +0100	[thread overview]
Message-ID: <4bb00bf5-5fe5-794b-24b5-9f39e8c5b505@foss.st.com> (raw)
In-Reply-To: <de661f344d554feb9e14a78e742e9bb1@SFHDAG2NODE3.st.com>

Hi Marek,

On 12/9/20 11:11 AM, Patrick DELAUNAY wrote:
> From: Marek Vasut <marex@denx.de>
> Sent: vendredi 9 octobre 2020 23:08
>
> The default state of SD bus and clock line is logical HI. SD card IO is open-drain and pulls the bus lines LO. Always enable the SD bus pull ups to guarantee this behavior. Note that on systems with bus voltage level shifter on the SD bus, the pull ups might also be built into the level shifter, however that should have no negative impact.
>
> Signed-off-by: Marek Vasut <marex@denx.de>
> Cc: Patrice Chotard <patrice.chotard@st.com>
> Cc: Patrick Delaunay <patrick.delaunay@st.com>
> ---
>   arch/arm/dts/stm32mp15-pinctrl.dtsi | 8 ++++----
>   1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/arch/arm/dts/stm32mp15-pinctrl.dtsi b/arch/arm/dts/stm32mp15-pinctrl.dtsi
> index 154832983c..2f8ff44a7a 100644
> --- a/arch/arm/dts/stm32mp15-pinctrl.dtsi
> +++ b/arch/arm/dts/stm32mp15-pinctrl.dtsi
> @@ -1184,13 +1184,13 @@
>   				 <STM32_PINMUX('D', 2, AF12)>; /* SDMMC1_CMD */
>   			slew-rate = <1>;
>   			drive-push-pull;
> -			bias-disable;
> +			bias-pull-up;
>   		};
>   		pins2 {
>   			pinmux = <STM32_PINMUX('C', 12, AF12)>; /* SDMMC1_CK */
>   			slew-rate = <2>;
>   			drive-push-pull;
> -			bias-disable;
> +			bias-pull-up;
>   		};
>   	};
>   
> @@ -1340,13 +1340,13 @@
>   				 <STM32_PINMUX('G', 6, AF10)>; /* SDMMC2_CMD */
>   			slew-rate = <1>;
>   			drive-push-pull;
> -			bias-disable;
> +			bias-pull-up;
>   		};
>   		pins2 {
>   			pinmux = <STM32_PINMUX('E', 3, AF9)>; /* SDMMC2_CK */
>   			slew-rate = <2>;
>   			drive-push-pull;
> -			bias-disable;
> +			bias-pull-up;
>   		};
>   	};
>   
> --
> 2.28.0
>
I don't see consensus on this device tree modification in Linux kernel 
side [1].

And for the DH board the modification is now done in SOM dtsi files 
after [2].

So can I close this patchset in patchwork ?

And if the modification is accepted in kernel device tree , I will get 
it with my next device

tree alignment...

[1] 
https://st-md-mailman.stormreply.com/pipermail/linux-stm32/2020-October/008554.html

[2] "ARM: dts: stm32: Enable internal pull-ups for SDMMC1 on DHCOM SoM 
<http://patchwork.ozlabs.org/project/uboot/list/?series=217761>"

http://patchwork.ozlabs.org/project/uboot/list/?series=217761&state=*

Regards

Patrick