[PATCH 1/2] ARM: dts: stm32: Enable internal pull-ups for SDMMC1 on DHCOM SoM

[Alexandre TORGUE]

Hi Marek

On 12/1/20 12:14 PM, Marek Vasut wrote:
> 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 on DHCOM SoM. Note that on SoMs with SD bus
> voltage level shifter, the pull ups are built into the level shifter,
> however that has no negative impact.
> 
> Signed-off-by: Marek Vasut <marex at denx.de>
> Cc: Alexandre Torgue <alexandre.torgue at st.com>
> Cc: Maxime Coquelin <mcoquelin.stm32 at gmail.com>
> Cc: Patrice Chotard <patrice.chotard at st.com>
> Cc: Patrick Delaunay <patrick.delaunay at st.com>
> Cc: linux-stm32 at st-md-mailman.stormreply.com
> To: linux-arm-kernel at lists.infradead.org
> ---
>   arch/arm/boot/dts/stm32mp15xx-dhcom-som.dtsi | 14 ++++++++++++++
>   1 file changed, 14 insertions(+)
> 
> diff --git a/arch/arm/boot/dts/stm32mp15xx-dhcom-som.dtsi b/arch/arm/boot/dts/stm32mp15xx-dhcom-som.dtsi
> index daff5318f301..97c6e0cd582c 100644
> --- a/arch/arm/boot/dts/stm32mp15xx-dhcom-som.dtsi
> +++ b/arch/arm/boot/dts/stm32mp15xx-dhcom-som.dtsi
> @@ -400,6 +400,20 @@ &sdmmc1 {
>   	status = "okay";
>   };
>   
> +&sdmmc1_b4_pins_a {
> +	/*
> +	 * SD bus pull-up resistors:
> +	 * - optional on SoMs with SD voltage translator
> +	 * - mandatory on SoMs without SD voltage translator
> +	 */
> +	pins1 {
> +		bias-pull-up;
> +	};
> +	pins2 {
> +		bias-pull-up;
> +	};
> +};
> +
>   &sdmmc2 {
>   	pinctrl-names = "default", "opendrain", "sleep";
>   	pinctrl-0 = <&sdmmc2_b4_pins_a &sdmmc2_d47_pins_a>;
> 

Applied on stm32-next.

Thanks.
Alex