Re: [RFC PATCH v3.1 13/27] mmc: sdhci-uhs2: add set_power() to support vdd2

[AKASHI Takahiro <takahiro.akashi@linaro.org>]

On Thu, Nov 26, 2020 at 10:16:27AM +0200, Adrian Hunter wrote:
> On 6/11/20 4:27 am, AKASHI Takahiro wrote:
> > This is a UHS-II version of sdhci's set_power operation.
> > VDD2, as well as VDD, is handled here.
> > 
> > Signed-off-by: Ben Chuang <ben.chuang@genesyslogic.com.tw>
> > Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
> > ---
> >  drivers/mmc/host/sdhci-uhs2.c | 80 +++++++++++++++++++++++++++++++++++
> >  drivers/mmc/host/sdhci-uhs2.h |  2 +
> >  drivers/mmc/host/sdhci.c      | 58 +++++++++++++++----------
> >  drivers/mmc/host/sdhci.h      |  2 +
> >  4 files changed, 119 insertions(+), 23 deletions(-)
> > 
> > diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
> > index e2b9743fe17d..2bf78cc4e9ed 100644
> > --- a/drivers/mmc/host/sdhci-uhs2.c
> > +++ b/drivers/mmc/host/sdhci-uhs2.c
> > @@ -98,6 +98,86 @@ void sdhci_uhs2_reset(struct sdhci_host *host, u16 mask)
> >  }
> >  EXPORT_SYMBOL_GPL(sdhci_uhs2_reset);
> >  
> > +void sdhci_uhs2_set_power(struct sdhci_host *host, unsigned char mode,
> > +			  unsigned short vdd)
> 
> This function isn't used, so let's rename it sdhci_uhs2_set_power_noreg and
> drop regulator support.

I have no strong opinion, but here Ben might want to further rework
the new sdhci_uhs2_set_power_noreg() now that it is almost the same as
GLI's gl9755_set_power()(, adding a new quirk?).

> > +{
> > +	struct mmc_host *mmc = host->mmc;
> > +	u8 pwr;
> > +
> > +	/* FIXME: check if flags & MMC_UHS2_SUPPORT? */
> > +	if (!(host->mmc->caps & MMC_CAP_UHS2)) {
> 
> As commented in another patch, please use a helper fn

As said, I would defer this.

> > +		sdhci_set_power(host, mode, vdd);
> > +		return;
> > +	}
> > +
> > +	if (mode != MMC_POWER_OFF) {
> > +		pwr = sdhci_get_vdd_value(vdd);
> 
> Simpler to open code this esp. as there are only 2 valid values:
> 
> 		switch (1 << vdd) {

Can you ignore MMC_VDD_165_195 and MMC_VDD_20_21 here?

> 		case MMC_VDD_29_30..MMC_VDD_30_31:
> 			pwr = SDHCI_POWER_300;
> 			break;
> 		case MMC_VDD_32_33..MMC_VDD_33_34:
> 			pwr = SDHCI_POWER_330;
> 			break;
> 		default:
> 			WARN(1, "%s: Invalid vdd %#x\n",
> 			     mmc_hostname(host->mmc), vdd);
> 			break;
> 		}
> 
> 
> > +		if (!pwr)
> > +			WARN(1, "%s: Invalid vdd %#x\n",
> > +			     mmc_hostname(host->mmc), vdd);
> > +
> > +		pwr |= SDHCI_VDD2_POWER_180;
> > +	}
> > +
> > +	if (host->pwr == pwr)
> > +		return;
> > +	host ->pwr = pwr;
> > +
> > +	if (pwr == 0) {
> > +		sdhci_writeb(host, 0, SDHCI_POWER_CONTROL);
> > +
> > +		if (!IS_ERR(host->mmc->supply.vmmc))
> > +			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);
> > +		if (!IS_ERR_OR_NULL(host->mmc->supply.vmmc2))
> > +			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc2, 0);
> > +
> > +		if (host->quirks2 & SDHCI_QUIRK2_CARD_ON_NEEDS_BUS_ON)
> 
> Please drop support for legacy quirk SDHCI_QUIRK2_CARD_ON_NEEDS_BUS_ON

Okay.

> 
> > +			sdhci_runtime_pm_bus_off(host);
> > +	} else {
> > +		if (!IS_ERR(host->mmc->supply.vmmc))
> > +			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, vdd);
> > +		if (!IS_ERR_OR_NULL(host->mmc->supply.vmmc2))
> > +			/* support 1.8v only for now */
> > +			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc2,
> > +					      fls(MMC_VDD2_165_195) - 1);
> > +
> > +		/*
> > +		 * Spec says that we should clear the power reg before setting
> > +		 * a new value. Some controllers don't seem to like this though.
> > +		 */
> > +		if (!(host->quirks & SDHCI_QUIRK_SINGLE_POWER_WRITE))
> 
> Please drop support for legacy quirk here and several cases below.  As I
> mentioned in another patch, just put a comment somewhere listing what is
> not supported for UHS2 host controllers.

Okay.

-Takahiro Akashi

> 
> > +			sdhci_writeb(host, 0, SDHCI_POWER_CONTROL);
> > +
> > +		/*
> > +		 * At least the Marvell CaFe chip gets confused if we set the
> > +		 * voltage and set turn on power at the same time, so set the
> > +		 * voltage first.
> > +		 */
> > +		if (host->quirks & SDHCI_QUIRK_NO_SIMULT_VDD_AND_POWER)
> > +			sdhci_writeb(host, pwr, SDHCI_POWER_CONTROL);
> > +
> > +		/* vdd first */
> > +		pwr |= SDHCI_POWER_ON;
> > +		sdhci_writeb(host, pwr & 0xf, SDHCI_POWER_CONTROL);
> > +		mdelay(5);
> > +
> > +		pwr |= SDHCI_VDD2_POWER_ON;
> > +		sdhci_writeb(host, pwr, SDHCI_POWER_CONTROL);
> > +		mdelay(5);
> > +
> > +		if (host->quirks2 & SDHCI_QUIRK2_CARD_ON_NEEDS_BUS_ON)
> > +			sdhci_runtime_pm_bus_on(host);
> > +
> > +		/*
> > +		 * Some controllers need an extra 10ms delay of 10ms before
> > +		 * they can apply clock after applying power
> > +		 */
> > +		if (host->quirks & SDHCI_QUIRK_DELAY_AFTER_POWER)
> > +			mdelay(10);
> > +	}
> > +}
> > +EXPORT_SYMBOL_GPL(sdhci_uhs2_set_power);
> > +
> >  /*****************************************************************************\
> >   *                                                                           *
> >   * Driver init/exit                                                          *
> > diff --git a/drivers/mmc/host/sdhci-uhs2.h b/drivers/mmc/host/sdhci-uhs2.h
> > index 7bb7a0d67109..3c19d8e44c36 100644
> > --- a/drivers/mmc/host/sdhci-uhs2.h
> > +++ b/drivers/mmc/host/sdhci-uhs2.h
> > @@ -211,5 +211,7 @@ struct sdhci_host;
> >  
> >  void sdhci_uhs2_dump_regs(struct sdhci_host *host);
> >  void sdhci_uhs2_reset(struct sdhci_host *host, u16 mask);
> > +void sdhci_uhs2_set_power(struct sdhci_host *host, unsigned char mode,
> > +			  unsigned short vdd);
> >  
> >  #endif /* __SDHCI_UHS2_H */
> > diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> > index af336bdb4305..0b741eb546cb 100644
> > --- a/drivers/mmc/host/sdhci.c
> > +++ b/drivers/mmc/host/sdhci.c
> > @@ -187,13 +187,14 @@ static void sdhci_disable_card_detection(struct sdhci_host *host)
> >  	sdhci_set_card_detection(host, false);
> >  }
> >  
> > -static void sdhci_runtime_pm_bus_on(struct sdhci_host *host)
> > +void sdhci_runtime_pm_bus_on(struct sdhci_host *host)
> >  {
> >  	if (host->bus_on)
> >  		return;
> >  	host->bus_on = true;
> >  	pm_runtime_get_noresume(host->mmc->parent);
> >  }
> > +EXPORT_SYMBOL_GPL(sdhci_runtime_pm_bus_on);
> >  
> >  void sdhci_runtime_pm_bus_off(struct sdhci_host *host)
> >  {
> > @@ -2017,36 +2018,47 @@ static void sdhci_set_power_reg(struct sdhci_host *host, unsigned char mode,
> >  		sdhci_writeb(host, 0, SDHCI_POWER_CONTROL);
> >  }
> >  
> > +unsigned short sdhci_get_vdd_value(unsigned short vdd)
> > +{
> > +	u8 pwr;
> > +
> > +	switch (1 << vdd) {
> > +	case MMC_VDD_165_195:
> > +	/*
> > +	 * Without a regulator, SDHCI does not support 2.0v
> > +	 * so we only get here if the driver deliberately
> > +	 * added the 2.0v range to ocr_avail. Map it to 1.8v
> > +	 * for the purpose of turning on the power.
> > +	 */
> > +	case MMC_VDD_20_21:
> > +		pwr = SDHCI_POWER_180;
> > +		break;
> > +	case MMC_VDD_29_30:
> > +	case MMC_VDD_30_31:
> > +		pwr = SDHCI_POWER_300;
> > +		break;
> > +	case MMC_VDD_32_33:
> > +	case MMC_VDD_33_34:
> > +		pwr = SDHCI_POWER_330;
> > +		break;
> > +	default:
> > +		pwr = 0;
> > +	}
> > +
> > +	return pwr;
> > +}
> > +EXPORT_SYMBOL_GPL(sdhci_get_vdd_value);
> > +
> >  void sdhci_set_power_noreg(struct sdhci_host *host, unsigned char mode,
> >  			   unsigned short vdd)
> >  {
> >  	u8 pwr = 0;
> >  
> >  	if (mode != MMC_POWER_OFF) {
> > -		switch (1 << vdd) {
> > -		case MMC_VDD_165_195:
> > -		/*
> > -		 * Without a regulator, SDHCI does not support 2.0v
> > -		 * so we only get here if the driver deliberately
> > -		 * added the 2.0v range to ocr_avail. Map it to 1.8v
> > -		 * for the purpose of turning on the power.
> > -		 */
> > -		case MMC_VDD_20_21:
> > -			pwr = SDHCI_POWER_180;
> > -			break;
> > -		case MMC_VDD_29_30:
> > -		case MMC_VDD_30_31:
> > -			pwr = SDHCI_POWER_300;
> > -			break;
> > -		case MMC_VDD_32_33:
> > -		case MMC_VDD_33_34:
> > -			pwr = SDHCI_POWER_330;
> > -			break;
> > -		default:
> > +		pwr = sdhci_get_vdd_value(vdd);
> > +		if (!pwr)
> >  			WARN(1, "%s: Invalid vdd %#x\n",
> >  			     mmc_hostname(host->mmc), vdd);
> > -			break;
> > -		}
> >  	}
> >  
> >  	if (host->pwr == pwr)
> > diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> > index b9932423db08..2b5b8295cf92 100644
> > --- a/drivers/mmc/host/sdhci.h
> > +++ b/drivers/mmc/host/sdhci.h
> > @@ -831,6 +831,7 @@ static inline void sdhci_read_caps(struct sdhci_host *host)
> >  	__sdhci_read_caps(host, NULL, NULL, NULL);
> >  }
> >  
> > +void sdhci_runtime_pm_bus_on(struct sdhci_host *host);
> >  void sdhci_runtime_pm_bus_off(struct sdhci_host *host);
> >  u16 sdhci_calc_clk(struct sdhci_host *host, unsigned int clock,
> >  		   unsigned int *actual_clock);
> > @@ -841,6 +842,7 @@ void sdhci_set_power(struct sdhci_host *host, unsigned char mode,
> >  void sdhci_set_power_and_bus_voltage(struct sdhci_host *host,
> >  				     unsigned char mode,
> >  				     unsigned short vdd);
> > +unsigned short sdhci_get_vdd_value(unsigned short vdd);
> >  void sdhci_set_power_noreg(struct sdhci_host *host, unsigned char mode,
> >  			   unsigned short vdd);
> >  void sdhci_request(struct mmc_host *mmc, struct mmc_request *mrq);
> > 
>