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Date:   Mon, 14 Sep 2020 14:45:37 +0900
From:   AKASHI Takahiro <takahiro.akashi@linaro.org>
To:     Adrian Hunter <adrian.hunter@intel.com>
Cc:     Ben Chuang <benchuanggli@gmail.com>, ulf.hansson@linaro.org,
        linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org,
        ben.chuang@genesyslogic.com.tw, greg.tu@genesyslogic.com.tw
Subject: Re: [RFC PATCH V3 15/21] mmc: sdhci: UHS-II support, modify
 set_power() to handle vdd2
Message-ID: <20200914054537.GA2738017@laputa>
Mail-Followup-To: AKASHI Takahiro <takahiro.akashi@linaro.org>,
        Adrian Hunter <adrian.hunter@intel.com>,
        Ben Chuang <benchuanggli@gmail.com>, ulf.hansson@linaro.org,
        linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org,
        ben.chuang@genesyslogic.com.tw, greg.tu@genesyslogic.com.tw
References: <20200710111140.29725-1-benchuanggli@gmail.com>
 <97c43596-a18f-4c7a-c226-5209772d91d1@intel.com>
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Adrian,

On Fri, Aug 21, 2020 at 05:11:18PM +0300, Adrian Hunter wrote:
> On 10/07/20 2:11 pm, Ben Chuang wrote:
> > From: AKASHI Takahiro <takahiro.akashi@linaro.org>
> > 
> > VDD2 is used for powering UHS-II interface.
> > Modify sdhci_set_power_and_bus_voltage(), sdhci_set_power_noreg()
> > and sdhci_set_power_noreg() to handle VDD2.
> 
> vdd2 is always 1.8 V and I suspect there may never be support for anything
> else, so we should start with 1.8 V only.

What do you mean here?
You don't want to add an extra argument, vdd2, to sdhci_set_power().
Correct?

> Also can we create uhs2_set_power_reg() and uhs2_set_power_noreg() and use
> the existing ->set_power() callback

Again what do you expect here?

Do you want to see any platform-specific mmc driver who supports UHS-II
to implement its own call back like:

void sdhci_foo_set_power(struct sdhci_host *host, unsigned char mode,
                                  unsigned short vdd)
{
        sdhci_set_power(host, mode,vdd);

        /* in case that sdhci_uhs2 module is not inserted */
        if (!(mmc->caps & MMC_CAP_UHS2))
                return;

        /* vdd2 specific operation */
        if (IS_ERR_OR_NULL(host->mmc->supply.vmmc2))
                sdhci_uhs2_set_power_noreg(host, mode);
        else
                sdhci_uhs2_set_power_reg(host, mode);

        /* maybe more platform-specific initialization */
}

struct sdhci_ops sdhci_foo_ops = {
        .set_power = sdhci_foo_set_power,
        ...
}

Is this what you mean?
(I'm not quite sure yet that sdhci_ush2_set_power_noreg() can be split off
from sdhci_set_power_noreg().)

-Takahiro Akashi

}

> > 
> > Signed-off-by: Ben Chuang <ben.chuang@genesyslogic.com.tw>
> > Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
> > ---
> >  drivers/mmc/host/sdhci-omap.c     |  2 +-
> >  drivers/mmc/host/sdhci-pci-core.c |  4 +--
> >  drivers/mmc/host/sdhci-pxav3.c    |  4 +--
> >  drivers/mmc/host/sdhci-xenon.c    |  4 +--
> >  drivers/mmc/host/sdhci.c          | 42 ++++++++++++++++++++++++-------
> >  drivers/mmc/host/sdhci.h          |  9 +++----
> >  6 files changed, 43 insertions(+), 22 deletions(-)
> > 
> > diff --git a/drivers/mmc/host/sdhci-omap.c b/drivers/mmc/host/sdhci-omap.c
> > index 1ec74c2d5c17..1926585debe5 100644
> > --- a/drivers/mmc/host/sdhci-omap.c
> > +++ b/drivers/mmc/host/sdhci-omap.c
> > @@ -678,7 +678,7 @@ static void sdhci_omap_set_clock(struct sdhci_host *host, unsigned int clock)
> >  }
> >  
> >  static void sdhci_omap_set_power(struct sdhci_host *host, unsigned char mode,
> > -			  unsigned short vdd)
> > +			  unsigned short vdd, unsigned short vdd2)
> >  {
> >  	struct mmc_host *mmc = host->mmc;
> >  
> > diff --git a/drivers/mmc/host/sdhci-pci-core.c b/drivers/mmc/host/sdhci-pci-core.c
> > index bb6802448b2f..40f5a24a8982 100644
> > --- a/drivers/mmc/host/sdhci-pci-core.c
> > +++ b/drivers/mmc/host/sdhci-pci-core.c
> > @@ -629,12 +629,12 @@ static int bxt_get_cd(struct mmc_host *mmc)
> >  #define SDHCI_INTEL_PWR_TIMEOUT_UDELAY	100
> >  
> >  static void sdhci_intel_set_power(struct sdhci_host *host, unsigned char mode,
> > -				  unsigned short vdd)
> > +				  unsigned short vdd, unsigned short vdd2)
> >  {
> >  	int cntr;
> >  	u8 reg;
> >  
> > -	sdhci_set_power(host, mode, vdd);
> > +	sdhci_set_power(host, mode, vdd, -1);
> >  
> >  	if (mode == MMC_POWER_OFF)
> >  		return;
> > diff --git a/drivers/mmc/host/sdhci-pxav3.c b/drivers/mmc/host/sdhci-pxav3.c
> > index e55037ceda73..457e9425339a 100644
> > --- a/drivers/mmc/host/sdhci-pxav3.c
> > +++ b/drivers/mmc/host/sdhci-pxav3.c
> > @@ -298,12 +298,12 @@ static void pxav3_set_uhs_signaling(struct sdhci_host *host, unsigned int uhs)
> >  }
> >  
> >  static void pxav3_set_power(struct sdhci_host *host, unsigned char mode,
> > -			    unsigned short vdd)
> > +			    unsigned short vdd, unsigned short vdd2)
> >  {
> >  	struct mmc_host *mmc = host->mmc;
> >  	u8 pwr = host->pwr;
> >  
> > -	sdhci_set_power_noreg(host, mode, vdd);
> > +	sdhci_set_power_noreg(host, mode, vdd, -1);
> >  
> >  	if (host->pwr == pwr)
> >  		return;
> > diff --git a/drivers/mmc/host/sdhci-xenon.c b/drivers/mmc/host/sdhci-xenon.c
> > index 4703cd540c7f..2b0ebb91895a 100644
> > --- a/drivers/mmc/host/sdhci-xenon.c
> > +++ b/drivers/mmc/host/sdhci-xenon.c
> > @@ -214,12 +214,12 @@ static void xenon_set_uhs_signaling(struct sdhci_host *host,
> >  }
> >  
> >  static void xenon_set_power(struct sdhci_host *host, unsigned char mode,
> > -		unsigned short vdd)
> > +		unsigned short vdd, unsigned short vdd2)
> >  {
> >  	struct mmc_host *mmc = host->mmc;
> >  	u8 pwr = host->pwr;
> >  
> > -	sdhci_set_power_noreg(host, mode, vdd);
> > +	sdhci_set_power_noreg(host, mode, vdd, -1);
> >  
> >  	if (host->pwr == pwr)
> >  		return;
> > diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> > index d38d734ec83f..ca3d4a506e01 100644
> > --- a/drivers/mmc/host/sdhci.c
> > +++ b/drivers/mmc/host/sdhci.c
> > @@ -2089,12 +2089,15 @@ void sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
> >  EXPORT_SYMBOL_GPL(sdhci_set_clock);
> >  
> >  static void sdhci_set_power_reg(struct sdhci_host *host, unsigned char mode,
> > -				unsigned short vdd)
> > +				unsigned short vdd, unsigned short vdd2)
> >  {
> >  	struct mmc_host *mmc = host->mmc;
> >  
> >  	mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, vdd);
> >  
> > +	if (mmc->caps & MMC_CAP_UHS2 && !IS_ERR(mmc->supply.vmmc2))
> > +		mmc_regulator_set_ocr(mmc, mmc->supply.vmmc2, vdd2);
> > +
> >  	if (mode != MMC_POWER_OFF)
> >  		sdhci_writeb(host, SDHCI_POWER_ON, SDHCI_POWER_CONTROL);
> >  	else
> > @@ -2102,7 +2105,7 @@ static void sdhci_set_power_reg(struct sdhci_host *host, unsigned char mode,
> >  }
> >  
> >  void sdhci_set_power_noreg(struct sdhci_host *host, unsigned char mode,
> > -			   unsigned short vdd)
> > +			   unsigned short vdd, unsigned short vdd2)
> >  {
> >  	u8 pwr = 0;
> >  
> > @@ -2133,6 +2136,20 @@ void sdhci_set_power_noreg(struct sdhci_host *host, unsigned char mode,
> >  		}
> >  	}
> >  
> > +	if (mode != MMC_POWER_OFF) {
> > +		if (vdd2 != (unsigned short)-1) {
> > +			switch (1 << vdd2) {
> > +			case MMC_VDD2_165_195:
> > +				pwr |= SDHCI_VDD2_POWER_180;
> > +				break;
> > +			default:
> > +				WARN(1, "%s: Invalid vdd2 %#x\n",
> > +				     mmc_hostname(host->mmc), vdd2);
> > +				break;
> > +			}
> > +		}
> > +	}
> > +
> >  	if (host->pwr == pwr)
> >  		return;
> >  
> > @@ -2159,7 +2176,13 @@ void sdhci_set_power_noreg(struct sdhci_host *host, unsigned char mode,
> >  			sdhci_writeb(host, pwr, SDHCI_POWER_CONTROL);
> >  
> >  		pwr |= SDHCI_POWER_ON;
> > +		if (vdd2 != (unsigned short)-1)
> > +			pwr |= SDHCI_VDD2_POWER_ON;
> > +
> > +		sdhci_writeb(host, pwr & 0xf, SDHCI_POWER_CONTROL);
> > +		mdelay(5);
> >  		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);
> > @@ -2175,12 +2198,12 @@ void sdhci_set_power_noreg(struct sdhci_host *host, unsigned char mode,
> >  EXPORT_SYMBOL_GPL(sdhci_set_power_noreg);
> >  
> >  void sdhci_set_power(struct sdhci_host *host, unsigned char mode,
> > -		     unsigned short vdd)
> > +		     unsigned short vdd, unsigned short vdd2)
> >  {
> >  	if (IS_ERR(host->mmc->supply.vmmc))
> > -		sdhci_set_power_noreg(host, mode, vdd);
> > +		sdhci_set_power_noreg(host, mode, vdd, vdd2);
> >  	else
> > -		sdhci_set_power_reg(host, mode, vdd);
> > +		sdhci_set_power_reg(host, mode, vdd, vdd2);
> >  }
> >  EXPORT_SYMBOL_GPL(sdhci_set_power);
> >  
> > @@ -2192,14 +2215,15 @@ EXPORT_SYMBOL_GPL(sdhci_set_power);
> >   */
> >  void sdhci_set_power_and_bus_voltage(struct sdhci_host *host,
> >  				     unsigned char mode,
> > -				     unsigned short vdd)
> > +				     unsigned short vdd,
> > +				     unsigned short vdd2)
> >  {
> >  	if (!IS_ERR(host->mmc->supply.vmmc)) {
> >  		struct mmc_host *mmc = host->mmc;
> >  
> >  		mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, vdd);
> >  	}
> > -	sdhci_set_power_noreg(host, mode, vdd);
> > +	sdhci_set_power_noreg(host, mode, vdd, -1);
> >  }
> >  EXPORT_SYMBOL_GPL(sdhci_set_power_and_bus_voltage);
> >  
> > @@ -2377,9 +2401,9 @@ void sdhci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
> >  	}
> >  
> >  	if (host->ops->set_power)
> > -		host->ops->set_power(host, ios->power_mode, ios->vdd);
> > +		host->ops->set_power(host, ios->power_mode, ios->vdd, -1);
> >  	else
> > -		sdhci_set_power(host, ios->power_mode, ios->vdd);
> > +		sdhci_set_power(host, ios->power_mode, ios->vdd, -1);
> >  
> >  	/* 4.0 host support */
> >  	if (host->version >= SDHCI_SPEC_400) {
> > diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> > index ecf55394ea46..f6732f33f29f 100644
> > --- a/drivers/mmc/host/sdhci.h
> > +++ b/drivers/mmc/host/sdhci.h
> > @@ -689,7 +689,7 @@ struct sdhci_ops {
> >  
> >  	void	(*set_clock)(struct sdhci_host *host, unsigned int clock);
> >  	void	(*set_power)(struct sdhci_host *host, unsigned char mode,
> > -			     unsigned short vdd);
> > +			     unsigned short vdd, unsigned short vdd2);
> >  
> >  	u32		(*irq)(struct sdhci_host *host, u32 intmask);
> >  
> > @@ -852,13 +852,10 @@ u16 sdhci_calc_clk(struct sdhci_host *host, unsigned int clock,
> >  		   unsigned int *actual_clock);
> >  void sdhci_set_clock(struct sdhci_host *host, unsigned int clock);
> >  void sdhci_enable_clk(struct sdhci_host *host, u16 clk);
> > -void sdhci_set_power(struct sdhci_host *host, unsigned char mode,
> > -		     unsigned short vdd);
> >  void sdhci_set_power_and_bus_voltage(struct sdhci_host *host,
> >  				     unsigned char mode,
> > -				     unsigned short vdd);
> > -void sdhci_set_power_noreg(struct sdhci_host *host, unsigned char mode,
> > -			   unsigned short vdd);
> > +				     unsigned short vdd,
> > +				     unsigned short vdd2);
> >  void sdhci_request(struct mmc_host *mmc, struct mmc_request *mrq);
> >  int sdhci_request_atomic(struct mmc_host *mmc, struct mmc_request *mrq);
> >  void sdhci_set_bus_width(struct sdhci_host *host, int width);
> > 
>