From: Marek Vasut <marex@denx.de>
Date: Tue, 1 Dec 2020 10:29:17 +0000 (+0100)
Subject: ARM: dts: stm32: Enable internal pull-ups for SDMMC1 on DHCOM SoM
X-Git-Url: http://git.dujemihanovic.xyz/html/index.html?a=commitdiff_plain;h=845c6720eca92be09127f7d306349ab31dbf372d;p=u-boot.git

ARM: dts: stm32: Enable internal pull-ups for SDMMC1 on DHCOM SoM

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@denx.de>
Cc: Patrice Chotard <patrice.chotard@st.com>
Cc: Patrick Delaunay <patrick.delaunay@st.com>
Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
---

diff --git a/arch/arm/dts/stm32mp15xx-dhcom.dtsi b/arch/arm/dts/stm32mp15xx-dhcom.dtsi
index f022d8395c..9049245c5b 100644
--- a/arch/arm/dts/stm32mp15xx-dhcom.dtsi
+++ b/arch/arm/dts/stm32mp15xx-dhcom.dtsi
@@ -339,6 +339,20 @@
 	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";
 	pinctrl-0 = <&sdmmc2_b4_pins_a &sdmmc2_d47_pins_a>;