Messages in this thread | | | Date | Tue, 15 Nov 2022 11:07:19 +0100 | From | Marco Felsch <> | Subject | Re: [PATCH V5 08/12] arm64: dts: imx8mn-evk: set off-on-delay-us in regulator |
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On 22-11-15, Peng Fan (OSS) wrote: > From: Peng Fan <peng.fan@nxp.com> > > 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: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Marco Felsch <m.felsch@pengutronix.de>
> --- > arch/arm64/boot/dts/freescale/imx8mn-evk.dtsi | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/arch/arm64/boot/dts/freescale/imx8mn-evk.dtsi b/arch/arm64/boot/dts/freescale/imx8mn-evk.dtsi > index 261c36540079..2b4395854283 100644 > --- a/arch/arm64/boot/dts/freescale/imx8mn-evk.dtsi > +++ b/arch/arm64/boot/dts/freescale/imx8mn-evk.dtsi > @@ -36,6 +36,7 @@ reg_usdhc2_vmmc: regulator-usdhc2 { > regulator-min-microvolt = <3300000>; > regulator-max-microvolt = <3300000>; > gpio = <&gpio2 19 GPIO_ACTIVE_HIGH>; > + off-on-delay-us = <12000>; > enable-active-high; > }; > > -- > 2.37.1 > > >
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