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Message-ID: <832d6c37-a6c5-4468-9a23-1637b2affb90@kwiboo.se>
Date: Thu, 2 May 2024 14:17:58 +0200
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Subject: Re: [PATCH v2 2/2] arm64: dts: rockchip: Add Radxa ROCK 3C
To: Dragan Simic <dsimic@manjaro.org>, Folker Schwesinger
 <dev@folker-schwesinger.de>
Cc: Chukun Pan <amadeus@jmu.edu.cn>, Heiko Stuebner <heiko@sntech.de>,
 Conor Dooley <conor+dt@kernel.org>, Krzysztof Kozlowski
 <krzk+dt@kernel.org>, Rob Herring <robh@kernel.org>,
 linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org,
 linux-kernel@vger.kernel.org, devicetree@vger.kernel.org
References: <20240428123618.72170-1-amadeus@jmu.edu.cn>
 <20240428123618.72170-3-amadeus@jmu.edu.cn>
 <D0X7UJELGST3.2IL1AFDJ89N07@folker-schwesinger.de>
 <ded928414323ef4be51f2575d00ba7d1@manjaro.org>
Content-Language: en-US
From: Jonas Karlman <jonas@kwiboo.se>
In-Reply-To: <ded928414323ef4be51f2575d00ba7d1@manjaro.org>
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Hi Dragan and Folker,

On 2024-05-02 03:28, Dragan Simic wrote:
> Hello Folker,
> 
> On 2024-04-30 07:42, Folker Schwesinger wrote:
>> On Sun Apr 28, 2024 at 2:36 PM CEST, Chukun Pan wrote:
>>> [...]
>>> +&sdhci {
>>> +	bus-width = <8>;
>>> +	max-frequency = <200000000>;
>>> +	mmc-hs200-1_8v;
>>
>> Out of curiosity, does this board also support HS400? From a very brief
>> look this board seems quite similar to Rock 4 series boards, that do
>> support HS400.
> 
> In a word, no, unfortunately.  In more detail, the Rockchip RK3566
> and RK3568 SoCs support the eMMC modes up to and including HS200, but
> not the HS400 mode.

The datasheet for RK3568 only mention HS200 mode, however, HS400 mode is
working in U-Boot after adjusting tap number for transmit clock [1].
Linux may need similar adjustment to make HS400 mode work on RK3568.

RK3566 that this board use only support HS200, as specified in datasheet.

[1] https://source.denx.de/u-boot/u-boot/-/commit/5c053f3adc69eaf83645b5d44c6adbb2d49a3fa7

Regards,
Jonas

> 
>>> +	non-removable;
>>> +	pinctrl-names = "default";
>>> +	pinctrl-0 = <&emmc_bus8 &emmc_clk &emmc_cmd &emmc_datastrobe>;
>>> +	vmmc-supply = <&vcc_3v3>;
>>> +	vqmmc-supply = <&vcc_1v8>;
>>> +	status = "okay";
>>> +};
>>