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From:   =?UTF-8?B?Q2zDqW1lbnQgUMOpcm9u?= <peron.clem@gmail.com>
Date:   Fri, 2 Oct 2020 17:40:20 +0200
Message-ID: <CAJiuCccgdG0MNi8-q1HCC=FiUKpNSv_HvdyS0jEzab5+b=Enqg@mail.gmail.com>
Subject: Re: [PATCH] arm64: dts: allwinner: h6: add eMMC voltage property for
 Beelink GS1
To:     Maxime Ripard <maxime@cerno.tech>
Cc:     Rob Herring <robh+dt@kernel.org>, Chen-Yu Tsai <wens@csie.org>,
        devicetree <devicetree@vger.kernel.org>,
        linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
        linux-kernel <linux-kernel@vger.kernel.org>
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Hi Maxime,

On Wed, 30 Sep 2020 at 12:27, Maxime Ripard <maxime@cerno.tech> wrote:
>
> Hi,
>
> On Mon, Sep 28, 2020 at 05:00:37PM +0200, Cl=C3=A9ment P=C3=A9ron wrote:
> > VQMMC supply is connected to BLDO2 which provides 1.8V.
> >
> > Let's reflect this in the device-tree.
>
> This commit log doesn't really explain what is going on though?
>
> > Fixes: 089bee8dd119 ("arm64: dts: allwinner: h6: Introduce Beelink GS1 =
board")
> > Signed-off-by: Cl=C3=A9ment P=C3=A9ron <peron.clem@gmail.com>
> > ---
> >  arch/arm64/boot/dts/allwinner/sun50i-h6-beelink-gs1.dts | 1 +
> >  1 file changed, 1 insertion(+)
> >
> > diff --git a/arch/arm64/boot/dts/allwinner/sun50i-h6-beelink-gs1.dts b/=
arch/arm64/boot/dts/allwinner/sun50i-h6-beelink-gs1.dts
> > index 049c21718846..3f20d2c9bbbb 100644
> > --- a/arch/arm64/boot/dts/allwinner/sun50i-h6-beelink-gs1.dts
> > +++ b/arch/arm64/boot/dts/allwinner/sun50i-h6-beelink-gs1.dts
> > @@ -145,6 +145,7 @@ &mmc2 {
> >       vqmmc-supply =3D <&reg_bldo2>;
>
> The Device Tree already expresses that the vqmmc supply is connected to
> BLDO2 which provides 1.8V here (together with the reg_bldo2 node).
>
> >       non-removable;
> >       cap-mmc-hw-reset;
> > +     mmc-hs200-1_8v;
>
> Whereas this indicates that the eMMC supports the HS200 MMC mode at 1.8V

What about a comment like this:

Sunxi mmc driver can't distinguish at runtime what's the I/O voltage
for HS200 mode.
Add a property in the device-tree to notify mmc core about this configurati=
on.


Regards,
Clement

>
> Maxime