[PATCH V6 11/12] arm64: dts: imx8m[m,q]-evk: change to use off-on-delay-us in regulator

Shawn Guo shawnguo at kernel.org
Fri Nov 18 19:11:58 PST 2022


On Thu, Nov 17, 2022 at 05:54:02PM +0800, Peng Fan (OSS) wrote:
> From: Haibo Chen <haibo.chen at 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: Haibo Chen <haibo.chen at nxp.com>
> Signed-off-by: Peng Fan <peng.fan at nxp.com>
> Reviewed-by: Marco Felsch <m.felsch at pengutronix.de>

Applied, thanks!



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