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From:   Chen-Yu Tsai <wens@csie.org>
Date:   Fri, 29 Nov 2019 17:26:39 +0800
Message-ID: <CAGb2v64oCx90LQScKTiHVyHLd6c7Rgs_g5L79Yr1J8kgS8-Kyg@mail.gmail.com>
Subject: Re: [linux-sunxi] [PATCH 1/3] arm64: dts: allwinner: a64: olinuxino:
 Fix eMMC supply regulator
To:     Stefan Mavrodiev <stefan@olimex.com>
Cc:     Maxime Ripard <mripard@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        "moderated list:ARM/Allwinner sunXi SoC support" 
        <linux-arm-kernel@lists.infradead.org>,
        "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
        <devicetree@vger.kernel.org>,
        open list <linux-kernel@vger.kernel.org>,
        linux-sunxi <linux-sunxi@googlegroups.com>
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On Fri, Nov 29, 2019 at 5:14 PM Stefan Mavrodiev <stefan@olimex.com> wrote:
>
> A64-OLinuXino-eMMC uses 1.8V for eMMC supply. This is done via a triple
> jumper, which sets VCC-PL to either 1.8V or 3.3V. This setting is different
> for boards with and without eMMC.
>
> This is not a big issue for DDR52 mode, however the eMMC will not work in
> HS200/HS400, since these modes explicitly requires 1.8V.
>
> Signed-off-by: Stefan Mavrodiev <stefan@olimex.com>
> ---
>  arch/arm64/boot/dts/allwinner/sun50i-a64-olinuxino-emmc.dts | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm64/boot/dts/allwinner/sun50i-a64-olinuxino-emmc.dts b/arch/arm64/boot/dts/allwinner/sun50i-a64-olinuxino-emmc.dts
> index 96ab0227e82d..7d135decbd53 100644
> --- a/arch/arm64/boot/dts/allwinner/sun50i-a64-olinuxino-emmc.dts
> +++ b/arch/arm64/boot/dts/allwinner/sun50i-a64-olinuxino-emmc.dts
> @@ -14,8 +14,8 @@
>  &mmc2 {
>         pinctrl-names = "default";
>         pinctrl-0 = <&mmc2_pins>;
> -       vmmc-supply = <&reg_dcdc1>;
> -       vqmmc-supply = <&reg_dcdc1>;
> +       vmmc-supply = <&reg_eldo1>;

If I'm reading the schematics correctly, VCC on the eMMC is from 3.3V.
This corresponds to the vmmc-supply property. So you shouldn't change it.

> +       vqmmc-supply = <&reg_eldo1>;

vqmmc-supply is from the VCC-PC rail, which is the one you say is triple-
jumpered. So this change makes sense.

ChenYu