[PATCH] arm64: dts: rockchip: Enable SPI NOR flash on Rock64

[frieder.schrempf@exceet.de (Frieder Schrempf)]

On 26.09.2018 06:53, Chen-Yu Tsai wrote:
> The Pine64 Rock64 board comes with a GigaDevice GD25Q128CSIG
> or GD25Q127CSIG chip, which is a 128 Mbit SPI NOR flash chip
> that supports the JEDEC read-ID command.
> 
> This patch enables the SPI controller and adds a device node
> for the flash chip using the generic "jedec,spi-nor" comaptible.
> 
> Signed-off-by: Chen-Yu Tsai <wens@csie.org>
> ---
> 
> This was working on linux-next 20180910, but now fails on linux-next
> 20180925, with the following error messages:
> 
>      m25p80 spi0.0: error -22 reading 9f
>      m25p80: probe of spi0.0 failed with error -2
> 
> Reverting the spi/for-next branch makes it work again:
> 
>      m25p80 spi0.0: gd25q128 (16384 Kbytes)
> 
> Not sure what's up.

The reason is probably an issue that was introduced here: [1], and it 
was fixed here: [2].

[1] 
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/drivers/spi?id=380583227c0c7f52383b0cd5c0e2de93ed31d553
[2] 
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/drivers/spi?id=4c53f98555fdbf1cc291cab8ffa5e1507a4f25d9

> 
> ---
>   arch/arm64/boot/dts/rockchip/rk3328-rock64.dts | 12 ++++++++++++
>   1 file changed, 12 insertions(+)
> 
> diff --git a/arch/arm64/boot/dts/rockchip/rk3328-rock64.dts b/arch/arm64/boot/dts/rockchip/rk3328-rock64.dts
> index 9ee4f57557f3..2170cf63845e 100644
> --- a/arch/arm64/boot/dts/rockchip/rk3328-rock64.dts
> +++ b/arch/arm64/boot/dts/rockchip/rk3328-rock64.dts
> @@ -290,6 +290,18 @@
>   	};
>   };
>   
> +&spi0 {
> +	status = "okay";
> +
> +	spiflash at 0 {
> +		compatible = "jedec,spi-nor";
> +		reg = <0>;
> +
> +		/* maximum speed for Rockchip SPI */
> +		spi-max-frequency = <50000000>;
> +	};
> +};
> +
>   &tsadc {
>   	rockchip,hw-tshut-mode = <0>;
>   	rockchip,hw-tshut-polarity = <0>;
>