Re: [PATCH u-boot-marvell 10/11] arm: mvebu: turris_mox: Fix unstable board topology reading

[Stefan Roese <sr@denx.de>]

On 11/3/21 03:02, Marek Behún wrote:
> From: Marek Behún <marek.behun@nic.cz>
> 
> The pre-relocation board topology reading in board_fix_fdt() is
> unstable: sometimes wrong data are read from the SPI bus.
> 
> This is due to wrong order of SPI bus configuration instructions: we
> first need to set the pins to SPI mode, and only after that configure
> the bus.
> 
> Also add a 1ms delay before enabling chip-select, so that the clock pin
> is high for some time before reading the bus.
> 
> Signed-off-by: Marek Behún <marek.behun@nic.cz>

Reviewed-by: Stefan Roese <sr@denx.de>

Thanks,
Stefan

> ---
>   board/CZ.NIC/turris_mox/turris_mox.c | 4 +++-
>   1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/board/CZ.NIC/turris_mox/turris_mox.c b/board/CZ.NIC/turris_mox/turris_mox.c
> index 502f6fc010..809ce82d20 100644
> --- a/board/CZ.NIC/turris_mox/turris_mox.c
> +++ b/board/CZ.NIC/turris_mox/turris_mox.c
> @@ -56,9 +56,11 @@ int board_fix_fdt(void *blob)
>   	 * to read SPI by reading/writing SPI registers directly
>   	 */
>   
> -	writel(0x10df, ARMADA_37XX_SPI_CFG);
>   	/* put pin from GPIO to SPI mode */
>   	clrbits_le32(ARMADA_37XX_NB_GPIO_SEL, BIT(12));
> +	/* configure cpol, cpha, prescale */
> +	writel(0x10df, ARMADA_37XX_SPI_CFG);
> +	mdelay(1);
>   	/* enable SPI CS1 */
>   	setbits_le32(ARMADA_37XX_SPI_CTRL, BIT(17));
>   
> 

Viele Grüße,
Stefan Roese

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