[PATCH 5/9] ram: stm32mp1: tuning: deactivate derating during BIST test

[Patrice CHOTARD]

On 3/6/20 11:14 AM, Patrick Delaunay wrote:
> The derating (timing parameter derating using MR4 read value)
> can't be activated during BIST test, as the MR4 read answer will
> be not understood by BIST (BISTGSR.BDONE bit stay at 0,
> BISTWCSR.DXWCNT = 0x206 instead of BISTWCR.BWCNT = 0x200).
>
> This patch only impacts the tuning on LPDDR2/LPDDR3,
> if derateen.derate_enable = 1.
>
> Signed-off-by: Patrick Delaunay <patrick.delaunay at st.com>
> ---
>
>  drivers/ram/stm32mp1/stm32mp1_tuning.c | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)
>
> diff --git a/drivers/ram/stm32mp1/stm32mp1_tuning.c b/drivers/ram/stm32mp1/stm32mp1_tuning.c
> index cab6cf087a..37d3ec8fef 100644
> --- a/drivers/ram/stm32mp1/stm32mp1_tuning.c
> +++ b/drivers/ram/stm32mp1/stm32mp1_tuning.c
> @@ -1288,11 +1288,16 @@ static enum test_result do_read_dqs_gating(struct stm32mp1_ddrctl *ctl,
>  {
>  	u32 rfshctl3 = readl(&ctl->rfshctl3);
>  	u32 pwrctl = readl(&ctl->pwrctl);
> +	u32 derateen = readl(&ctl->derateen);
>  	enum test_result res;
>  
> +	writel(0x0, &ctl->derateen);
>  	stm32mp1_refresh_disable(ctl);
> +
>  	res = read_dqs_gating(ctl, phy, string);
> +
>  	stm32mp1_refresh_restore(ctl, rfshctl3, pwrctl);
> +	writel(derateen, &ctl->derateen);
>  
>  	return res;
>  }
> @@ -1303,11 +1308,16 @@ static enum test_result do_bit_deskew(struct stm32mp1_ddrctl *ctl,
>  {
>  	u32 rfshctl3 = readl(&ctl->rfshctl3);
>  	u32 pwrctl = readl(&ctl->pwrctl);
> +	u32 derateen = readl(&ctl->derateen);
>  	enum test_result res;
>  
> +	writel(0x0, &ctl->derateen);
>  	stm32mp1_refresh_disable(ctl);
> +
>  	res = bit_deskew(ctl, phy, string);
> +
>  	stm32mp1_refresh_restore(ctl, rfshctl3, pwrctl);
> +	writel(derateen, &ctl->derateen);
>  
>  	return res;
>  }
> @@ -1318,11 +1328,16 @@ static enum test_result do_eye_training(struct stm32mp1_ddrctl *ctl,
>  {
>  	u32 rfshctl3 = readl(&ctl->rfshctl3);
>  	u32 pwrctl = readl(&ctl->pwrctl);
> +	u32 derateen = readl(&ctl->derateen);
>  	enum test_result res;
>  
> +	writel(0x0, &ctl->derateen);
>  	stm32mp1_refresh_disable(ctl);
> +
>  	res = eye_training(ctl, phy, string);
> +
>  	stm32mp1_refresh_restore(ctl, rfshctl3, pwrctl);
> +	writel(derateen, &ctl->derateen);
>  
>  	return res;
>  }

Acked-by: Patrice Chotard <patrice.chotard at st.com>

Thanks

Patrice