[PATCH v3 3/6] mmc: zynq_sdhci: Use Mask writes for Tap delays

[Jaehoon Chung]

On 7/9/21 8:53 PM, Ashok Reddy Soma wrote:
> Restrict tap_delay value to the allowed size(8bits for itap and 6 bits
> for otap) before writing to the tap delay register.
> 
> Clear ITAP and OTAP delay bits before updating with the new tap value
> for Versal platform.
> 
> Signed-off-by: Ashok Reddy Soma <ashok.reddy.soma at xilinx.com>


Reviewed-by: Jaehoon Chung <jh80.chung at samsung.com>

Best Regards,
Jaehoon Chung

> ---
> 
> Changes in v3:
>  - Updated macro's with BIT() and GENMASK() for readability
> 
>  drivers/mmc/zynq_sdhci.c | 58 +++++++++++++++++++++-------------------
>  1 file changed, 31 insertions(+), 27 deletions(-)
> 
> diff --git a/drivers/mmc/zynq_sdhci.c b/drivers/mmc/zynq_sdhci.c
> index f65a87a4e1..bf638e9675 100644
> --- a/drivers/mmc/zynq_sdhci.c
> +++ b/drivers/mmc/zynq_sdhci.c
> @@ -19,11 +19,13 @@
>  #include <sdhci.h>
>  #include <zynqmp_tap_delay.h>
>  
> -#define SDHCI_ARASAN_ITAPDLY_REGISTER   0xF0F8
> -#define SDHCI_ARASAN_OTAPDLY_REGISTER   0xF0FC
> -#define SDHCI_ITAPDLY_CHGWIN            0x200
> -#define SDHCI_ITAPDLY_ENABLE            0x100
> -#define SDHCI_OTAPDLY_ENABLE            0x40
> +#define SDHCI_ARASAN_ITAPDLY_REGISTER	0xF0F8
> +#define SDHCI_ARASAN_ITAPDLY_SEL_MASK	GENMASK(7, 0)
> +#define SDHCI_ARASAN_OTAPDLY_REGISTER	0xF0FC
> +#define SDHCI_ARASAN_OTAPDLY_SEL_MASK	GENMASK(5, 0)
> +#define SDHCI_ITAPDLY_CHGWIN		BIT(9)
> +#define SDHCI_ITAPDLY_ENABLE		BIT(8)
> +#define SDHCI_OTAPDLY_ENABLE		BIT(6)
>  
>  #define SDHCI_TUNING_LOOP_COUNT		40
>  #define MMC_BANK2			0x2
> @@ -297,6 +299,7 @@ static int sdhci_versal_sdcardclk_set_phase(struct sdhci_host *host,
>  	struct mmc *mmc = (struct mmc *)host->mmc;
>  	u8 tap_delay, tap_max = 0;
>  	int timing = mode2timing[mmc->selected_mode];
> +	u32 regval;
>  
>  	/*
>  	 * This is applicable for SDHCI_SPEC_300 and above
> @@ -329,16 +332,16 @@ static int sdhci_versal_sdcardclk_set_phase(struct sdhci_host *host,
>  
>  	tap_delay = (degrees * tap_max) / 360;
>  
> +	/* Limit output tap_delay value to 6 bits */
> +	tap_delay &= SDHCI_ARASAN_OTAPDLY_SEL_MASK;
> +
>  	/* Set the Clock Phase */
> -	if (tap_delay) {
> -		u32 regval;
> -
> -		regval = sdhci_readl(host, SDHCI_ARASAN_OTAPDLY_REGISTER);
> -		regval |= SDHCI_OTAPDLY_ENABLE;
> -		sdhci_writel(host, regval, SDHCI_ARASAN_OTAPDLY_REGISTER);
> -		regval |= tap_delay;
> -		sdhci_writel(host, regval, SDHCI_ARASAN_OTAPDLY_REGISTER);
> -	}
> +	regval = sdhci_readl(host, SDHCI_ARASAN_OTAPDLY_REGISTER);
> +	regval |= SDHCI_OTAPDLY_ENABLE;
> +	sdhci_writel(host, regval, SDHCI_ARASAN_OTAPDLY_REGISTER);
> +	regval &= ~SDHCI_ARASAN_OTAPDLY_SEL_MASK;
> +	regval |= tap_delay;
> +	sdhci_writel(host, regval, SDHCI_ARASAN_OTAPDLY_REGISTER);
>  
>  	return 0;
>  }
> @@ -358,6 +361,7 @@ static int sdhci_versal_sampleclk_set_phase(struct sdhci_host *host,
>  	struct mmc *mmc = (struct mmc *)host->mmc;
>  	u8 tap_delay, tap_max = 0;
>  	int timing = mode2timing[mmc->selected_mode];
> +	u32 regval;
>  
>  	/*
>  	 * This is applicable for SDHCI_SPEC_300 and above
> @@ -390,20 +394,20 @@ static int sdhci_versal_sampleclk_set_phase(struct sdhci_host *host,
>  
>  	tap_delay = (degrees * tap_max) / 360;
>  
> +	/* Limit input tap_delay value to 8 bits */
> +	tap_delay &= SDHCI_ARASAN_ITAPDLY_SEL_MASK;
> +
>  	/* Set the Clock Phase */
> -	if (tap_delay) {
> -		u32 regval;
> -
> -		regval = sdhci_readl(host, SDHCI_ARASAN_ITAPDLY_REGISTER);
> -		regval |= SDHCI_ITAPDLY_CHGWIN;
> -		sdhci_writel(host, regval, SDHCI_ARASAN_ITAPDLY_REGISTER);
> -		regval |= SDHCI_ITAPDLY_ENABLE;
> -		sdhci_writel(host, regval, SDHCI_ARASAN_ITAPDLY_REGISTER);
> -		regval |= tap_delay;
> -		sdhci_writel(host, regval, SDHCI_ARASAN_ITAPDLY_REGISTER);
> -		regval &= ~SDHCI_ITAPDLY_CHGWIN;
> -		sdhci_writel(host, regval, SDHCI_ARASAN_ITAPDLY_REGISTER);
> -	}
> +	regval = sdhci_readl(host, SDHCI_ARASAN_ITAPDLY_REGISTER);
> +	regval |= SDHCI_ITAPDLY_CHGWIN;
> +	sdhci_writel(host, regval, SDHCI_ARASAN_ITAPDLY_REGISTER);
> +	regval |= SDHCI_ITAPDLY_ENABLE;
> +	sdhci_writel(host, regval, SDHCI_ARASAN_ITAPDLY_REGISTER);
> +	regval &= ~SDHCI_ARASAN_ITAPDLY_SEL_MASK;
> +	regval |= tap_delay;
> +	sdhci_writel(host, regval, SDHCI_ARASAN_ITAPDLY_REGISTER);
> +	regval &= ~SDHCI_ITAPDLY_CHGWIN;
> +	sdhci_writel(host, regval, SDHCI_ARASAN_ITAPDLY_REGISTER);
>  
>  	return 0;
>  }
>