[PATCH v2 2/2] arm64: dts: rockchip: Add Radxa ROCK 3C

[Jonas Karlman]

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";
>>> +};
>>