Re: [EXT] Re: [PATCH] mmc: sdhci-xenon: add gpio hard reset support

Jisheng Zhang
2017-08-16T02:49:32Z

On Wed, 16 Aug 2017 08:32:09 +0800 Shawn Lin wrote:

> Hi
>
> On 2017/8/16 6:40, Zhoujie Wu wrote:
> > Hi Shawn,
>
> >> ----------------------------------------------------------------------
> >> Hi
> >>
> >> On 2017/8/15 6:19, Zhoujie Wu wrote:
> >>> On some platforms, like armada3700, SD card need to
> >>> do hard reset by gpio toggling to make it work properly
> >>> after warm reset the board.
> >>
> >> I don't get this that SD card need to do hard reset...
> >>
> >> I assume what you talk about is either for eMMC or a power-cycle
> >> for SD card.
> >
> > The subject of the patch confused you. What I want is a power-cycle for
> > the SD card. The gpio is used to enable/disable the vdd power supply
> > for sd card.
> > Actually on a3700, when warm reset the board, their is no power-cycle
> > for SD card, which will lead sd card can't response correct ocr and
> > never set S18A unless a power-cycle.
> > This is the purpose I submit this patch.
> >
>
> Well, if that is the case, I suggest you to use regulator-gpio.

Oh yes! If the gpio is for power, why not make use of regulator? then
except the dts, we don't need do anything.