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Subject: Re: [PATCH] arm64: dts: rockchip: include uhs support for rockpro64
To:     =?UTF-8?Q?Christian_L=c3=b6hle?= <CLoehle@hyperstone.com>,
        "robh+dt@kernel.org" <robh+dt@kernel.org>,
        "heiko@sntech.de" <heiko@sntech.de>,
        "jbx6244@gmail.com" <jbx6244@gmail.com>,
        "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
        "linux-arm-kernel@lists.infradead.org" 
        <linux-arm-kernel@lists.infradead.org>,
        "linux-rockchip@lists.infradead.org" 
        <linux-rockchip@lists.infradead.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
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From:   Soeren Moch <smoch@web.de>
Message-ID: <8466ba81-7334-d23c-8496-b3d11adcd595@web.de>
Date:   Wed, 28 Apr 2021 10:43:36 +0200
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On 28.04.21 08:28, Christian L=C3=B6hle wrote:
> Oh okay, I was not aware of this issue
> and have not encountered it yet.
> But wouldn't it be more appropriate
> to get u-boot to power cycle the host controller at boot?
This is not about power-cycling the host controller. We have to
power-cycle the SD card itself to switch it back to default speed and
3.3V operation. This is the mode the boot ROM expects.

Unfortunately there is no separate power switch for SD card power on
RockPro64. So we have to power-cycle the whole SoC. This obviously
cannot be done easily after reboot in u-boot, but can be done in trusted
firmware (TF-A, was called ATF before) at reboot. This is what I use on
my boards, see the hack in [1]. Rockchip seems to prefer soft reset,
maybe someone from Rockchip can comment on the exact reasons.

Regards,
Soeren


[1] https://github.com/s-moch/arm-trusted-firmware-rockpro64
>
>
> From: Soeren Moch <smoch@web.de>
> Sent: Tuesday, April 27, 2021 5:07 PM
> To: Christian L=C3=B6hle <CLoehle@hyperstone.com>; robh+dt@kernel.org <r=
obh+dt@kernel.org>; heiko@sntech.de <heiko@sntech.de>; jbx6244@gmail.com <=
jbx6244@gmail.com>; devicetree@vger.kernel.org <devicetree@vger.kernel.org=
>; linux-arm-kernel@lists.infradead.org <linux-arm-kernel@lists.infradead.=
org>; linux-rockchip@lists.infradead.org <linux-rockchip@lists.infradead.o=
rg>; linux-kernel@vger.kernel.org <linux-kernel@vger.kernel.org>
> Subject: Re: [PATCH] arm64: dts: rockchip: include uhs support for rockp=
ro64
> =C2=A0
> On 27.04.21 08:20, Christian L?hle wrote:
>> The DesignWare Host Controller has full UHS-I support, so use it.
> Enabling this UHS support makes 'reboot' hang when booting the RockPro64
> from SD card. It would work when booting from eMMC, or with a modified
> ATF which does a power cycle on reboot.
>
> But for general use it is not save to enable UHS support, or did I miss
> some recent changes?
>
> Regards,
> Soeren
>> Signed-off-by: Christian Loehle <cloehle@hyperstone.com>
>> ---
>> =C2=A0 arch/arm64/boot/dts/rockchip/rk3399-rockpro64.dtsi | 1 +
>> =C2=A0 1 file changed, 1 insertion(+)
>>
>> diff --git a/arch/arm64/boot/dts/rockchip/rk3399-rockpro64.dtsi b/arch/=
arm64/boot/dts/rockchip/rk3399-rockpro64.dtsi
>> index 6bff8db7d33e..d22a489ec214 100644
>> --- a/arch/arm64/boot/dts/rockchip/rk3399-rockpro64.dtsi
>> +++ b/arch/arm64/boot/dts/rockchip/rk3399-rockpro64.dtsi
>> @@ -722,6 +722,7 @@ &sdmmc {
>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 max-frequency =3D <150000000=
>;
>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 pinctrl-names =3D "default";
>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 pinctrl-0 =3D <&sdmmc_clk &s=
dmmc_cmd &sdmmc_bus4>;
>> +=C2=A0=C2=A0=C2=A0=C2=A0 sd-uhs-sdr104;
>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 vmmc-supply =3D <&vcc3v0_sd>=
;
>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 vqmmc-supply =3D <&vcc_sdio>=
;
>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 status =3D "okay";
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