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

[Biju Das]

Hi Wolfram,

Thanks for the feedback.

> -----Original Message-----
> From: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
> Sent: 17 June 2026 13:41
> Subject: Re: [PATCH v17 08/17] mmc: renesas_sdhi: Add tuning_delay hw_info flag
> 
> On Wed, Jun 03, 2026 at 07:57:08AM +0100, Biju wrote:
> > From: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> >
> > 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@xxxxxxxxxxxxxx>
> > ---
> > 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?

OK.

> 
> 
> >  /* 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?

OK, you mean this function along with SH_MOBILE_SDHI_SCC_* macro upwards?

Cheers,
Biju