Re: [PATCH v1 3/5] mmc: sdhci_am654: Add missing OTAP/ITAP enable

[Andrew Davis <afd@ti.com>]

On 1/31/24 3:50 PM, Judith Mendez wrote:
> Currently the OTAP/ITAP delay enable functionality is missing in
> the am654_set_clock function which is used for MMC0 on AM62p
> and AM64x devices. The OTAP delay is not enabled when timing <
> SDR25 bus speed mode. The ITAP delay is not enabled for all bus
> speed modes.
> 
> Add this OTAP/ITAP delay functionality according to the datasheet
> [1] OTAPDLYENA and ITAPDLYENA for MMC0.
> 
> [1] https://www.ti.com/lit/ds/symlink/am62p.pdf
> 
> Fixes: 8ee5fc0e0b3b ("mmc: sdhci_am654: Update OTAPDLY writes")
> Signed-off-by: Judith Mendez <jm@ti.com>
> ---
>   drivers/mmc/host/sdhci_am654.c | 48 +++++++++++++++++++---------------
>   1 file changed, 27 insertions(+), 21 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci_am654.c b/drivers/mmc/host/sdhci_am654.c
> index ff18a274b6f2..5ac82bc70706 100644
> --- a/drivers/mmc/host/sdhci_am654.c
> +++ b/drivers/mmc/host/sdhci_am654.c
> @@ -143,6 +143,7 @@ struct sdhci_am654_data {
>   	struct regmap *base;
>   	int otap_del_sel[ARRAY_SIZE(td)];
>   	int itap_del_sel[ARRAY_SIZE(td)];
> +	u8 itap_del_ena[ARRAY_SIZE(td)];

Why u8? Seems this is always manipulated as a u32. In fact
the same is true for `otap_del_sel` and `itap_del_sel` above.
Those needed fixed also.

>   	int clkbuf_sel;
>   	int trm_icp;
>   	int drv_strength;
> @@ -171,11 +172,13 @@ struct sdhci_am654_driver_data {
>   };
>   
>   static void sdhci_am654_write_itapdly(struct sdhci_am654_data *sdhci_am654,
> -				      u32 itapdly)
> +				      u32 itapdly, u32 enable)
>   {
>   	/* Set ITAPCHGWIN before writing to ITAPDLY */
>   	regmap_update_bits(sdhci_am654->base, PHY_CTRL4, ITAPCHGWIN_MASK,
>   			   0x1 << ITAPCHGWIN_SHIFT);
> +	regmap_update_bits(sdhci_am654->base, PHY_CTRL4, ITAPDLYENA_MASK,
> +			   enable << ITAPDLYENA_SHIFT);
>   	regmap_update_bits(sdhci_am654->base, PHY_CTRL4, ITAPDLYSEL_MASK,
>   			   itapdly << ITAPDLYSEL_SHIFT);
>   	regmap_update_bits(sdhci_am654->base, PHY_CTRL4, ITAPCHGWIN_MASK, 0);
> @@ -249,7 +252,8 @@ static void sdhci_am654_setup_dll(struct sdhci_host *host, unsigned int clock,
>   		return;
>   	}
>   
> -	sdhci_am654_write_itapdly(sdhci_am654, sdhci_am654->itap_del_sel[timing]);
> +	sdhci_am654_write_itapdly(sdhci_am654, sdhci_am654->itap_del_sel[timing],
> +				  sdhci_am654->itap_del_ena[timing]);
>   }
>   
>   static void sdhci_am654_setup_delay_chain(struct sdhci_am654_data *sdhci_am654,
> @@ -263,8 +267,8 @@ static void sdhci_am654_setup_delay_chain(struct sdhci_am654_data *sdhci_am654,
>   	mask = SELDLYTXCLK_MASK | SELDLYRXCLK_MASK;
>   	regmap_update_bits(sdhci_am654->base, PHY_CTRL5, mask, val);
>   
> -	sdhci_am654_write_itapdly(sdhci_am654,
> -				  sdhci_am654->itap_del_sel[timing]);
> +	sdhci_am654_write_itapdly(sdhci_am654, sdhci_am654->itap_del_sel[timing],
> +				  sdhci_am654->itap_del_ena[timing]);
>   }
>   
>   static void sdhci_am654_set_clock(struct sdhci_host *host, unsigned int clock)
> @@ -273,20 +277,17 @@ static void sdhci_am654_set_clock(struct sdhci_host *host, unsigned int clock)
>   	struct sdhci_am654_data *sdhci_am654 = sdhci_pltfm_priv(pltfm_host);
>   	unsigned char timing = host->mmc->ios.timing;
>   	u32 otap_del_sel;
> -	u32 otap_del_ena;
>   	u32 mask, val;
>   
>   	regmap_update_bits(sdhci_am654->base, PHY_CTRL1, ENDLL_MASK, 0);
>   
>   	sdhci_set_clock(host, clock);
>   
> -	/* Setup DLL Output TAP delay */
> +	/* Setup Output TAP delay */
>   	otap_del_sel = sdhci_am654->otap_del_sel[timing];
> -	otap_del_ena = (timing > MMC_TIMING_UHS_SDR25) ? 1 : 0;
>   
>   	mask = OTAPDLYENA_MASK | OTAPDLYSEL_MASK;
> -	val = (otap_del_ena << OTAPDLYENA_SHIFT) |
> -	      (otap_del_sel << OTAPDLYSEL_SHIFT);
> +	val = (0x1 << OTAPDLYENA_SHIFT) | (otap_del_sel << OTAPDLYSEL_SHIFT);
>   
>   	/* Write to STRBSEL for HS400 speed mode */
>   	if (timing == MMC_TIMING_MMC_HS400) {
> @@ -319,14 +320,20 @@ static void sdhci_j721e_4bit_set_clock(struct sdhci_host *host,
>   	struct sdhci_am654_data *sdhci_am654 = sdhci_pltfm_priv(pltfm_host);
>   	unsigned char timing = host->mmc->ios.timing;
>   	u32 otap_del_sel;
> +	u32 itap_del_ena;
>   	u32 mask, val;
>   
> -	/* Setup DLL Output TAP delay */
> +	/* Setup Output TAP delay */
>   	otap_del_sel = sdhci_am654->otap_del_sel[timing];
>   
>   	mask = OTAPDLYENA_MASK | OTAPDLYSEL_MASK;
> -	val = (0x1 << OTAPDLYENA_SHIFT) |
> -	      (otap_del_sel << OTAPDLYSEL_SHIFT);
> +	val = (0x1 << OTAPDLYENA_SHIFT) | (otap_del_sel << OTAPDLYSEL_SHIFT);

You are not changing anything in this line, so why reformat it? If
you want to do some reformatting put it in a separate patch. And in
this case, I like it better how it was.

Andrew

> +
> +	itap_del_ena = sdhci_am654->itap_del_ena[timing];
> +
> +	mask |= ITAPDLYENA_MASK;
> +	val |= (itap_del_ena << ITAPDLYENA_SHIFT);
> +
>   	regmap_update_bits(sdhci_am654->base, PHY_CTRL4, mask, val);
>   
>   	regmap_update_bits(sdhci_am654->base, PHY_CTRL5, CLKBUFSEL_MASK,
> @@ -503,12 +510,8 @@ static int sdhci_am654_platform_execute_tuning(struct sdhci_host *host,
>   
>   	memset(fail_window, 0, sizeof(fail_window[0]) * ITAPDLY_LENGTH);
>   
> -	/* Enable ITAPDLY */
> -	regmap_update_bits(sdhci_am654->base, PHY_CTRL4, ITAPDLYENA_MASK,
> -			   1 << ITAPDLYENA_SHIFT);
> -
>   	for (itap = 0; itap < ITAPDLY_LENGTH; itap++) {
> -		sdhci_am654_write_itapdly(sdhci_am654, itap);
> +		sdhci_am654_write_itapdly(sdhci_am654, itap, 1);
>   
>   		curr_pass = !mmc_send_tuning(host->mmc, opcode, NULL);
>   
> @@ -532,7 +535,7 @@ static int sdhci_am654_platform_execute_tuning(struct sdhci_host *host,
>   	itap = sdhci_am654_calculate_itap(host, fail_window, fail_index,
>   					  (sdhci_am654->dll_enable ? true : false));
>   
> -	sdhci_am654_write_itapdly(sdhci_am654, itap);
> +	sdhci_am654_write_itapdly(sdhci_am654, itap, 1);
>   
>   	return 0;
>   }
> @@ -681,9 +684,12 @@ static int sdhci_am654_get_otap_delay(struct sdhci_host *host,
>   				host->mmc->caps2 &= ~td[i].capability;
>   		}
>   
> -		if (td[i].itap_binding)
> -			device_property_read_u32(dev, td[i].itap_binding,
> -						 &sdhci_am654->itap_del_sel[i]);
> +		if (td[i].itap_binding) {
> +			ret = device_property_read_u32(dev, td[i].itap_binding,
> +						       &sdhci_am654->itap_del_sel[i]);
> +				if (!ret)
> +					sdhci_am654->itap_del_ena[i] = 0x1;
> +		}
>   	}
>   
>   	return 0;