Re: [PATCH 3/4] mmc: fsl_esdhc: add pulse width detection workaround

[Jaehoon Chung]

On 3/17/21 11:01 PM, Michael Walle wrote:
> HS400 mode on the LS1028A SoC isn't reliable. The linux driver has a
> workaroung for the pulse width detection. Apply this workaround in
> u-boot, too.
> 
> This will make HS400 mode work reliably on the LS1028A SoC.
> 
> Signed-off-by: Michael Walle <mich...@walle.cc>
> ---
>  arch/arm/cpu/armv8/fsl-layerscape/Kconfig | 1 +
>  drivers/mmc/Kconfig                       | 3 +++
>  drivers/mmc/fsl_esdhc.c                   | 6 +++++-
>  include/fsl_esdhc.h                       | 3 +++
>  4 files changed, 12 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm/cpu/armv8/fsl-layerscape/Kconfig 
> b/arch/arm/cpu/armv8/fsl-layerscape/Kconfig
> index c0190a233e..9d1ba4c771 100644
> --- a/arch/arm/cpu/armv8/fsl-layerscape/Kconfig
> +++ b/arch/arm/cpu/armv8/fsl-layerscape/Kconfig
> @@ -48,6 +48,7 @@ config ARCH_LS1028A
>       select SYS_FSL_ERRATUM_A009942 if !TFABOOT
>       select SYS_FSL_ERRATUM_A050382
>       select SYS_FSL_ERRATUM_A011334
> +     select SYS_FSL_ESDHC_UNRELIABLE_PULSE_DETECTION_WORKAROUND
>       select RESV_RAM if GIC_V3_ITS
>       imply PANIC_HANG
>  
> diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig
> index 0b6755fd90..f7620c9cd1 100644
> --- a/drivers/mmc/Kconfig
> +++ b/drivers/mmc/Kconfig
> @@ -815,3 +815,6 @@ config SYS_FSL_ERRATUM_ESDHC_A001
>  
>  config SYS_FSL_ERRATUM_A011334
>       bool
> +
> +config SYS_FSL_ESDHC_UNRELIABLE_PULSE_DETECTION_WORKAROUND

How about using QUIRK instead of WORKAROUD

Best Regards,
Jaehoon Chung

> +     bool
> diff --git a/drivers/mmc/fsl_esdhc.c b/drivers/mmc/fsl_esdhc.c
> index 09ea1a9de9..7501fdb71e 100644
> --- a/drivers/mmc/fsl_esdhc.c
> +++ b/drivers/mmc/fsl_esdhc.c
> @@ -71,7 +71,8 @@ struct fsl_esdhc {
>       uint    sdtimingctl;    /* SD timing control register */
>       char    reserved8[20];  /* reserved */
>       uint    dllcfg0;        /* DLL config 0 register */
> -     char    reserved9[12];  /* reserved */
> +     uint    dllcfg1;        /* DLL config 1 register */
> +     char    reserved9[8];   /* reserved */
>       uint    dllstat0;       /* DLL status 0 register */
>       char    reserved10[664];/* reserved */
>       uint    esdhcctl;       /* eSDHC control register */
> @@ -767,6 +768,9 @@ static int esdhc_init_common(struct fsl_esdhc_priv *priv, 
> struct mmc *mmc)
>       /* Set timout to the maximum value */
>       esdhc_clrsetbits32(&regs->sysctl, SYSCTL_TIMEOUT_MASK, 14 << 16);
>  
> +     if 
> (IS_ENABLED(CONFIG_SYS_FSL_ESDHC_UNRELIABLE_PULSE_DETECTION_WORKAROUND))
> +             esdhc_clrbits32(&regs->dllcfg1, DLL_PD_PULSE_STRETCH_SEL);
> +
>       return 0;
>  }
>  
> diff --git a/include/fsl_esdhc.h b/include/fsl_esdhc.h
> index 850a304bd7..f86afe5dad 100644
> --- a/include/fsl_esdhc.h
> +++ b/include/fsl_esdhc.h
> @@ -190,6 +190,9 @@
>  #define DLL_RESET            0x40000000
>  #define DLL_FREQ_SEL         0x08000000
>  
> +/* DLL config 1 register */
> +#define DLL_PD_PULSE_STRETCH_SEL 0x80000000
> +
>  /* DLL status 0 register */
>  #define DLL_STS_SLV_LOCK     0x08000000
>  
>