Re: [PATCH] arm64: dts: rockchip: enable SD UHS-I on Firefly-RK3399

From: Heiko Stuebner <heiko@sntech.de>
To: Yaozhong Li <yaozhonguwl@gmail.com>,
	Shawn Lin <shawn.lin@rock-chips.com>
Cc: shawn.lin@rock-chips.com, Rob Herring <robh@kernel.org>,
	linux-arm-kernel@lists.infradead.org,
	linux-rockchip@lists.infradead.org
Subject: Re: [PATCH] arm64: dts: rockchip: enable SD UHS-I on Firefly-RK3399
Date: Sun, 01 Nov 2026 18:55:25 +0100	[thread overview]
Message-ID: <2120863.kXSN5OTJKJ@phil> (raw)
In-Reply-To: <b8221ba4-dccb-42f5-ae77-a6c087fa1d05@rock-chips.com>

Am Sonntag, 1. November 2026, 17:10:04 Mitteleuropäische Normalzeit schrieb Shawn Lin:
> 在 2026/09/22 星期二 13:50, Yaozhong Li 写道:
> > The SD slot on this board stays at 50 MHz with 3.3V signalling. The
> 
> ...
> 
> > 
> > I have no schematic for this board. The claim about what LDO4 feeds
> > rests on the vendor firmware device tree plus the measurements above.
> > 
> 
> It's easy to find one:
> https://github.com/armbian/armbian.github.io/blob/main/board-schematics/firefly-rk3399.pdf
> 
> Too bad it was designed this way! What if sdio-wifi is working on UHS
> modebut people insert a HighSpeed only sd card?

Hmm, when I read the schematics correctly, all parts of the sdio + wifi
supplied by vcc_1v8 (both APIO3_VDD_1V8 and also vddio of the wifi module
itself), while vcc_sdio only supplies SDMMC0_VDD?

Yaozhong Li: please trim that commit message down a lot, it doesn't
have to be novel size please.

Heiko

> 
> > The analysis and the commit message were drafted with the help of an
> > LLM-based assistant (Claude Code), cross-reviewed with a second one
> > (OpenAI Codex). The device tree change, the measurements and the final
> > wording are mine.
> > 
> >   arch/arm64/boot/dts/rockchip/rk3399-firefly.dts | 3 ++-
> >   1 file changed, 2 insertions(+), 1 deletion(-)
> > 
> > diff --git a/arch/arm64/boot/dts/rockchip/rk3399-firefly.dts b/arch/arm64/boot/dts/rockchip/rk3399-firefly.dts
> > index 0568dfa..7cabbc1 100644
> > --- a/arch/arm64/boot/dts/rockchip/rk3399-firefly.dts
> > +++ b/arch/arm64/boot/dts/rockchip/rk3399-firefly.dts
> > @@ -777,7 +777,6 @@ &sdio0 {
> >   
> >   	/* Power supply */
> >   	vqmmc-supply = <&vcc1v8_s3>;	/* IO line */
> > -	vmmc-supply = <&vcc_sdio>;	/* card's power */
> >   
> >   	#address-cells = <1>;
> >   	#size-cells = <0>;
> > @@ -804,6 +803,8 @@ &sdmmc {
> >   	max-frequency = <150000000>;
> >   	pinctrl-names = "default";
> >   	pinctrl-0 = <&sdmmc_clk &sdmmc_cmd &sdmmc_bus4>;
> > +	sd-uhs-sdr104;
> > +	vqmmc-supply = <&vcc_sdio>;
> >   	status = "okay";
> >   };
> >   
> > 
> > base-commit: 940de590b839f71d6dc846160534bf202401b8b7
> 
> 

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