Re: [PATCH v3 40/57] ram: rk3399: Update lpddr4 vref_mode_ac

[Kever Yang <kever.yang@xxxxxxxxxxxxxx>]

On 2019/7/16 下午7:57, Jagan Teki wrote:
> Update vref_mode_ac for lpddr4 based on VDDQ/3/2=16.8%
>
> Signed-off-by: Jagan Teki <jagan@xxxxxxxxxxxxxxxxxxxx>
> Signed-off-by: YouMin Chen <cym@xxxxxxxxxxxxxx>

Reviewed-by: Kever Yang <Kever.yang@xxxxxxxxxxxxxx>

Thanks,
 - Kever
> ---
>   drivers/ram/rockchip/sdram_rk3399.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/ram/rockchip/sdram_rk3399.c b/drivers/ram/rockchip/sdram_rk3399.c
> index 63763062f9..e3f1abf7e7 100644
> --- a/drivers/ram/rockchip/sdram_rk3399.c
> +++ b/drivers/ram/rockchip/sdram_rk3399.c
> @@ -366,7 +366,8 @@ static int phy_io_config(const struct chan_info *chan,
>   			vref_value_dq = (rd_vref - 15300) / 521;
>   		}
>   		vref_mode_ac = 0x6;
> -		vref_value_ac = 0x1f;
> +		/* VDDQ/3/2=16.8% */
> +		vref_value_ac = 0x3;
>   	} else if (params->base.dramtype == LPDDR3) {
>   		if (params->base.odt == 1) {
>   			vref_mode_dq = 0x5;  /* LPDDR3 ODT */



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