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Date: Fri, 15 Dec 2023 19:15:05 +0100
From: Dragan Simic <dsimic@manjaro.org>
To: Stefan Nagy <stefan.nagy@ixypsilon.net>
Cc: Heiko Stuebner <heiko@sntech.de>, linux-rockchip@lists.infradead.org,
 linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org,
 linux-kernel@vger.kernel.org
Subject: Re: [PATCH] arm64: dts: rockchip: Increase maximum frequency of SPI
 flash for ROCK Pi 4A/B/C
In-Reply-To: <20231215122848.59534-1-stefan.nagy@ixypsilon.net>
References: <20231215122848.59534-1-stefan.nagy@ixypsilon.net>
Message-ID: <33e632c38fa57053585c0016652ed8c8@manjaro.org>
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On 2023-12-15 13:28, Stefan Nagy wrote:
> The ROCK Pi 4A/B/C boards come with a 32 Mbit SPI NOR flash chip (XTX
> Technology Limited XT25F32) which has a maximum clock frequency of 108
> MHz. However, the Rockchip SPI controller driver limits the maximum
> SPI clock frequency to 50 MHz. Use this limit for spi-max-freq.
> 
> This patch has been tested on ROCK Pi 4A.
> 
> Signed-off-by: Stefan Nagy <stefan.nagy@ixypsilon.net>
> ---
>  arch/arm64/boot/dts/rockchip/rk3399-rock-pi-4a.dts | 2 +-
>  arch/arm64/boot/dts/rockchip/rk3399-rock-pi-4b.dts | 2 +-
>  arch/arm64/boot/dts/rockchip/rk3399-rock-pi-4c.dts | 2 +-
>  3 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/arm64/boot/dts/rockchip/rk3399-rock-pi-4a.dts
> b/arch/arm64/boot/dts/rockchip/rk3399-rock-pi-4a.dts
> index d5df8939a..30e63e62a 100644
> --- a/arch/arm64/boot/dts/rockchip/rk3399-rock-pi-4a.dts
> +++ b/arch/arm64/boot/dts/rockchip/rk3399-rock-pi-4a.dts
> @@ -19,6 +19,6 @@ &spi1 {
>  	flash@0 {
>  		compatible = "jedec,spi-nor";
>  		reg = <0>;
> -		spi-max-frequency = <10000000>;
> +		spi-max-frequency = <50000000>;
>  	};
>  };
> diff --git a/arch/arm64/boot/dts/rockchip/rk3399-rock-pi-4b.dts
> b/arch/arm64/boot/dts/rockchip/rk3399-rock-pi-4b.dts
> index bee6d7588..7122bf6c0 100644
> --- a/arch/arm64/boot/dts/rockchip/rk3399-rock-pi-4b.dts
> +++ b/arch/arm64/boot/dts/rockchip/rk3399-rock-pi-4b.dts
> @@ -37,7 +37,7 @@ &spi1 {
>  	flash@0 {
>  		compatible = "jedec,spi-nor";
>  		reg = <0>;
> -		spi-max-frequency = <10000000>;
> +		spi-max-frequency = <50000000>;
>  	};
>  };
> 
> diff --git a/arch/arm64/boot/dts/rockchip/rk3399-rock-pi-4c.dts
> b/arch/arm64/boot/dts/rockchip/rk3399-rock-pi-4c.dts
> index de2ebe4cb..8af75bc7c 100644
> --- a/arch/arm64/boot/dts/rockchip/rk3399-rock-pi-4c.dts
> +++ b/arch/arm64/boot/dts/rockchip/rk3399-rock-pi-4c.dts
> @@ -49,7 +49,7 @@ &spi1 {
>  	flash@0 {
>  		compatible = "jedec,spi-nor";
>  		reg = <0>;
> -		spi-max-frequency = <10000000>;
> +		spi-max-frequency = <50000000>;
>  	};
>  };

It would be better to upstream these changes to the Linux kernel first, 
and then sync them back to U-Boot.