[PATCH 1/2] ARM: dts: imx8m: increase off-on delay on the SD Vcc regulator

[Andrey Zhizhikin]

Some SD Card controller and power circuitry has increased capacitance,
which keeps the internal logic remains powered after regulator is switch
off. This is generally the case when card is switched to SD104 mode,
where a power cycle should be performed. In case if the card internal
logic remains powered, it causes a subsequent failure of mode
transition, effectively leading to failed enumeration.

Introduce a delay of 20 msec in order to provide a possibility for
internal card circuitry to drain voltages and perform a power cycle
correctly.

Similar fix is done in commit c49d0ac38a76 ("ARM: dts: rmobile: Increase
off-on delay on the SD Vcc regulator") targeted Renesas SOCs.

Signed-off-by: Andrey Zhizhikin <andrey.zhizhikin at leica-geosystems.com>
Cc: Stefano Babic <sbabic at denx.de>
---
 arch/arm/dts/imx8mm-beacon-kit-u-boot.dtsi | 4 ++++
 arch/arm/dts/imx8mm-evk-u-boot.dtsi        | 4 ++++
 arch/arm/dts/imx8mn-ddr4-evk-u-boot.dtsi   | 4 ++++
 arch/arm/dts/imx8mp-evk-u-boot.dtsi        | 4 ++++
 arch/arm/dts/imx8mq-evk.dts                | 1 +
 arch/arm/dts/imx8mq-phanbell.dts           | 1 +
 6 files changed, 18 insertions(+)

diff --git a/arch/arm/dts/imx8mm-beacon-kit-u-boot.dtsi b/arch/arm/dts/imx8mm-beacon-kit-u-boot.dtsi
index fc1aebb2fe..6d80a529ae 100644
--- a/arch/arm/dts/imx8mm-beacon-kit-u-boot.dtsi
+++ b/arch/arm/dts/imx8mm-beacon-kit-u-boot.dtsi
@@ -37,6 +37,10 @@
 	/delete-property/ assigned-clock-rates;
 };
 
+&reg_usdhc2_vmmc {
+	u-boot,off-on-delay-us = <20000>;
+};
+
 &fec1 {
 	phy-reset-gpios = <&gpio4 22 GPIO_ACTIVE_LOW>;
 };
diff --git a/arch/arm/dts/imx8mm-evk-u-boot.dtsi b/arch/arm/dts/imx8mm-evk-u-boot.dtsi
index b5c12105a9..9f77d3c6ff 100644
--- a/arch/arm/dts/imx8mm-evk-u-boot.dtsi
+++ b/arch/arm/dts/imx8mm-evk-u-boot.dtsi
@@ -46,6 +46,10 @@
 	u-boot,dm-spl;
 };
 
+&reg_usdhc2_vmmc {
+	u-boot,off-on-delay-us = <20000>;
+};
+
 &pinctrl_reg_usdhc2_vmmc {
 	u-boot,dm-spl;
 };
diff --git a/arch/arm/dts/imx8mn-ddr4-evk-u-boot.dtsi b/arch/arm/dts/imx8mn-ddr4-evk-u-boot.dtsi
index 4419679d4c..98b0b9891b 100644
--- a/arch/arm/dts/imx8mn-ddr4-evk-u-boot.dtsi
+++ b/arch/arm/dts/imx8mn-ddr4-evk-u-boot.dtsi
@@ -47,6 +47,10 @@
 	u-boot,dm-spl;
 };
 
+&reg_usdhc2_vmmc {
+	u-boot,off-on-delay-us = <20000>;
+};
+
 &pinctrl_uart2 {
 	u-boot,dm-spl;
 };
diff --git a/arch/arm/dts/imx8mp-evk-u-boot.dtsi b/arch/arm/dts/imx8mp-evk-u-boot.dtsi
index 24a93ac2d6..2452e9175c 100644
--- a/arch/arm/dts/imx8mp-evk-u-boot.dtsi
+++ b/arch/arm/dts/imx8mp-evk-u-boot.dtsi
@@ -48,6 +48,10 @@
 	u-boot,dm-spl;
 };
 
+&reg_usdhc2_vmmc {
+	u-boot,off-on-delay-us = <20000>;
+};
+
 &reg_usdhc2_vmmc {
 	u-boot,dm-spl;
 };
diff --git a/arch/arm/dts/imx8mq-evk.dts b/arch/arm/dts/imx8mq-evk.dts
index 55294ba9c8..9663683f69 100644
--- a/arch/arm/dts/imx8mq-evk.dts
+++ b/arch/arm/dts/imx8mq-evk.dts
@@ -39,6 +39,7 @@
 		regulator-max-microvolt = <3300000>;
 		gpio = <&gpio2 19 GPIO_ACTIVE_HIGH>;
 		enable-active-high;
+		u-boot,off-on-delay-us = <20000>;
 	};
 
 	buck2_reg: regulator-buck2 {
diff --git a/arch/arm/dts/imx8mq-phanbell.dts b/arch/arm/dts/imx8mq-phanbell.dts
index 4892ad5ee1..bc6b2638ee 100644
--- a/arch/arm/dts/imx8mq-phanbell.dts
+++ b/arch/arm/dts/imx8mq-phanbell.dts
@@ -34,6 +34,7 @@
 		regulator-max-microvolt = <3300000>;
 		gpio = <&gpio2 19 GPIO_ACTIVE_HIGH>;
 		enable-active-high;
+		u-boot,off-on-delay-us = <20000>;
 	};
 };
 
-- 
2.17.1