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arm64: dts: imx8m[m,q]-evk: change to use off-on-delay-us in regulator

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Some SD Card controller and power circuitry has increased capacitance,
so the usual toggling of regulator to power the card off and on
is insufficient.

According to SD spec, for sd card power reset operation, the sd card
supply voltage needs to be lower than 0.5v and keep over 1ms, otherwise,
next time power back the sd card supply voltage to 3.3v, sd card can't
support SD3.0 mode again.

This patch add the off-on-delay-us, make sure the sd power reset behavior
is align with the specification. Without this patch, when do quick system
suspend/resume test, some sd card can't work at SD3.0 mode after system
resume back.

Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Marco Felsch <m.felsch@pengutronix.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
This commit is contained in:
Haibo Chen 2022-11-17 17:54:02 +08:00 • committed by Shawn Guo
parent a8ea275d16
commit 2a6b56aafb
2 changed files with 2 additions and 0 deletions
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1
arch/arm64/boot/dts/freescale/imx8mm-evk.dtsi
View file

@ -56,6 +56,7 @@
regulator-min-microvolt = <3300000>;
regulator-max-microvolt = <3300000>;
gpio = <&gpio2 19 GPIO_ACTIVE_HIGH>;
off-on-delay-us = <20000>;
enable-active-high;
};

1
arch/arm64/boot/dts/freescale/imx8mq-evk.dts
View file

@ -46,6 +46,7 @@
regulator-min-microvolt = <3300000>;
regulator-max-microvolt = <3300000>;
gpio = <&gpio2 19 GPIO_ACTIVE_HIGH>;
off-on-delay-us = <20000>;
enable-active-high;
};