Re: [PATCH v17 08/17] mmc: renesas_sdhi: Add tuning_delay hw_info flag

[Wolfram Sang <wsa+renesas@sang-engineering.com>]

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On Wed, Jun 03, 2026 at 07:57:08AM +0100, Biju wrote:
> From: Biju Das <biju.das.jz@bp.renesas.com>
> 
> As per the RZ/G2L hardware manual, the TMPOUT bit field in the SCC_TMPPORT
> register needs to be set to 0 when transferring at 3.3V, and to 1 when
> transferring at 1.8V.
> 
> Add a tuning_delay bitfield to renesas_sdhi_hw_info to indicate hardware
> that requires an adjustment when the signal voltage changes.
> 
> Add sdhi_hw_info_rzg2l with tuning_delay = 1 and assign it to
> of_rzg2l_compatible, enabling the adjustment for RZ/G2L. All other
> platforms retain sdhi_hw_info_generic with tuning_delay = 0 and
> are unaffected.
> 
> Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
> ---
> v1->v2:
>  * No change.
> ---
>  drivers/mmc/host/renesas_sdhi.h               |  2 +
>  drivers/mmc/host/renesas_sdhi_core.c          | 83 +++++++++++--------
>  drivers/mmc/host/renesas_sdhi_internal_dmac.c |  8 +-
>  3 files changed, 58 insertions(+), 35 deletions(-)
> 
> diff --git a/drivers/mmc/host/renesas_sdhi.h b/drivers/mmc/host/renesas_sdhi.h
> index a42934e6d49d..a3c5fa368242 100644
> --- a/drivers/mmc/host/renesas_sdhi.h
> +++ b/drivers/mmc/host/renesas_sdhi.h
> @@ -44,6 +44,8 @@ struct renesas_sdhi_of_data {
>  struct renesas_sdhi_hw_info {
>  	u64 clk_mask;
>  	unsigned int max_divider;
> +	/* hardware features */
> +	unsigned tuning_delay:1;	/* Has tuning delay */
>  };
>  
>  struct renesas_sdhi_of_data_with_info {
> diff --git a/drivers/mmc/host/renesas_sdhi_core.c b/drivers/mmc/host/renesas_sdhi_core.c
> index 16ed6fd8470d..868ba6a6919e 100644
> --- a/drivers/mmc/host/renesas_sdhi_core.c
> +++ b/drivers/mmc/host/renesas_sdhi_core.c
> @@ -257,40 +257,6 @@ static int renesas_sdhi_card_busy(struct mmc_host *mmc)
>  		 TMIO_STAT_DAT0);
>  }
>  
> -static int renesas_sdhi_start_signal_voltage_switch(struct mmc_host *mmc,
> -						    struct mmc_ios *ios)
> -{
> -	struct tmio_mmc_host *host = mmc_priv(mmc);
> -	struct renesas_sdhi *priv = host_to_priv(host);
> -	struct pinctrl_state *pin_state;
> -	int ret;
> -
> -	switch (ios->signal_voltage) {
> -	case MMC_SIGNAL_VOLTAGE_330:
> -		pin_state = priv->pins_default;
> -		break;
> -	case MMC_SIGNAL_VOLTAGE_180:
> -		pin_state = priv->pins_uhs;
> -		break;
> -	default:
> -		return -EINVAL;
> -	}
> -
> -	/*
> -	 * If anything is missing, assume signal voltage is fixed at
> -	 * 3.3V and succeed/fail accordingly.
> -	 */
> -	if (IS_ERR(priv->pinctrl) || IS_ERR(pin_state))
> -		return ios->signal_voltage ==
> -			MMC_SIGNAL_VOLTAGE_330 ? 0 : -EINVAL;
> -
> -	ret = mmc_regulator_set_vqmmc(host->mmc, ios);
> -	if (ret < 0)
> -		return ret;
> -
> -	return pinctrl_select_state(priv->pinctrl, pin_state);
> -}
> -

I don't think this function needs to be moved downwards?


>  /* SCC registers */
>  #define SH_MOBILE_SDHI_SCC_DTCNTL	0x000
>  #define SH_MOBILE_SDHI_SCC_TAPSET	0x002
> @@ -351,6 +317,55 @@ static inline void sd_scc_write32(struct tmio_mmc_host *host,
>  	writel(val, priv->scc_ctl + (addr << host->bus_shift));
>  }
>  
> +static void renesas_sdhi_set_hw_adjustment_delay(struct tmio_mmc_host *host)
> +{
> +	struct renesas_sdhi *priv = host_to_priv(host);
> +
> +	if (!priv->info->tuning_delay)
> +		return;
> +
> +	if (host->mmc->ios.signal_voltage == MMC_SIGNAL_VOLTAGE_330)
> +		sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_TMPPORT2, 0x0);
> +	else
> +		sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_TMPPORT2, 0x1);
> +}

Isn't it enough to move this upwards? I don't see anything requiring
this function to be so late. Am I overlooking something?


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