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Message-ID: <fb57172e-2517-498c-9412-76f62929d24a@kwiboo.se>
Date: Mon, 8 Apr 2024 17:14:40 +0200
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Subject: Re: [PATCH 1/1] arm64: dts: rockchip: enable onboard spi flash for
 rock-3a
To: "=?UTF-8?Q?Heiko_St=C3=BCbner?=" <heiko@sntech.de>, Chukun Pan
 <amadeus@jmu.edu.cn>
Cc: 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: <20240408124005.182565-1-amadeus@jmu.edu.cn>
 <421ab43b-ff92-41c6-9904-3c7681c926be@kwiboo.se>
 <b32c284e-f3ec-44b0-abbd-7fa403bc9870@kwiboo.se> <3066222.xgJ6IN8ObU@diego>
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From: Jonas Karlman <jonas@kwiboo.se>
In-Reply-To: <3066222.xgJ6IN8ObU@diego>
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On 2024-04-08 17:04, Heiko Stübner wrote:
> Am Montag, 8. April 2024, 16:56:59 CEST schrieb Jonas Karlman:
>> On 2024-04-08 16:44, Jonas Karlman wrote:
>>> On 2024-04-08 14:40, Chukun Pan wrote:
>>>> There is a mx25u12835f spi flash on this board, enable it.
>>>>
>>>> [    2.525805] spi-nor spi4.0: mx25u12835f (16384 Kbytes)
>>>>
>>>> Signed-off-by: Chukun Pan <amadeus@jmu.edu.cn>
>>>> ---
>>>>  arch/arm64/boot/dts/rockchip/rk3568-rock-3a.dts | 12 ++++++++++++
>>>>  1 file changed, 12 insertions(+)
>>>>
>>>> diff --git a/arch/arm64/boot/dts/rockchip/rk3568-rock-3a.dts b/arch/arm64/boot/dts/rockchip/rk3568-rock-3a.dts
>>>> index a5e974ea659e..d8738cc47c73 100644
>>>> --- a/arch/arm64/boot/dts/rockchip/rk3568-rock-3a.dts
>>>> +++ b/arch/arm64/boot/dts/rockchip/rk3568-rock-3a.dts
>>>> @@ -757,6 +757,18 @@ &sdmmc2 {
>>>>  	status = "okay";
>>>>  };
>>>>  
>>>> +&sfc {
>>>
>>> This is missing:
>>>
>>> 	#address-cells = <1>;
>>> 	#size-cells = <0>;
>>>
>>>> +	status = "okay";
>>>> +
>>>> +	flash@0 {
>>>> +		compatible = "jedec,spi-nor";
>>>> +		reg = <0x0>;
>>>> +		spi-max-frequency = <50000000>;
>>>
>>> At least in U-Boot the spi clock only support 24, 100 or 200 mhz and I
>>> am pretty sure the spi flash support 100mhz, so I would suggest you test
>>> with 100mhz, same as used on other rk356x boards.
>>
>> Sorry, looked at spi clock instead of sfc clock.
>> sfc clock support 24, 50, 75, 100, 125 and 150 mhz.
> 
> I think in some previous discussion the agreement was that the node
> should specify the max frequency the flash supports and have the
> controller worry about its own clock ranges.

Interesting, sounds like there is a need to do some modification to spi
and clk drivers in U-Boot to support that.

> 
> Though in this case the 50MHz for the flash even matches the clock
> frequency supported by the sfc

I think the on-board spi nor flash support 104/108/133 mhz so 50 mhz is
wrong in any case.

Regards,
Jonas

> 
>