[U-Boot] [PATCH 3/9] mx23evk: Fix DDR pin iomux settings

[Marek Vasut]

Dear Fabio Estevam,

> From: Fabio Estevam <fabio.estevam at freescale.com>
> 
> Registers HW_PINCTRL_DRIVE9, HW_PINCTRL_DRIVE10, HW_PINCTRL_DRIVE11,
> HW_PINCTRL_DRIVE12, HW_PINCTRL_DRIVE13 and HW_PINCTRL_DRIVE14 control the
> drive strength and the voltage selection for the DDR pins.
> 
> The reset values of the voltage selection pins are '1', which is marked as
> 'reserved' in the mx23 reference manual.
> 
> Clear these bits for proper operation of DDR.
> 
> Also change MUX_CONFIG_EMI, which results in better stability and match the
> bootlets code from Freescale.
> 
> Signed-off-by: Fabio Estevam <fabio.estevam at freescale.com>

Uh, should the pinctrl/iomux stuff not set these up properly?

> ---
>  board/freescale/mx23evk/spl_boot.c |   12 +++++++++++-
>  1 file changed, 11 insertions(+), 1 deletion(-)
> 
> diff --git a/board/freescale/mx23evk/spl_boot.c
> b/board/freescale/mx23evk/spl_boot.c index b6f4e7e..035a29c 100644
> --- a/board/freescale/mx23evk/spl_boot.c
> +++ b/board/freescale/mx23evk/spl_boot.c
> @@ -26,7 +26,7 @@
>  #include <asm/arch/sys_proto.h>
> 
>  #define	MUX_CONFIG_SSP1	(MXS_PAD_3V3 | MXS_PAD_8MA | MXS_PAD_PULLUP)
> -#define	MUX_CONFIG_EMI	(MXS_PAD_3V3 | MXS_PAD_16MA | MXS_PAD_PULLUP)
> +#define	MUX_CONFIG_EMI	MXS_PAD_12MA
> 
>  const iomux_cfg_t iomux_setup[] = {
>  	/* DUART */
> @@ -110,5 +110,15 @@ void mxs_adjust_memory_params(uint32_t *dram_vals)
> 
>  void board_init_ll(void)
>  {
> +	struct mxs_pinctrl_regs *pinctrl =
> +		(struct mxs_pinctrl_regs *)MXS_PINCTRL_BASE;
> +	/* Clear the voltage bits for EMI pins as the reset value is invalid */
> +	writel(0, &pinctrl->drive9);
> +	writel(0, &pinctrl->drive10);
> +	writel(0, &pinctrl->drive11);
> +	writel(0, &pinctrl->drive12);
> +	writel(0, &pinctrl->drive13);
> +	writel(0, &pinctrl->drive14);
> +	writel(0, &pinctrl->drive9);
>  	mxs_common_spl_init(iomux_setup, ARRAY_SIZE(iomux_setup));
>  }

Best regards,
Marek Vasut