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References: <20221213090047.3805-1-victor.shih@genesyslogic.com.tw>
 <20221213090047.3805-12-victor.shih@genesyslogic.com.tw> <d828948f-2cd4-9bc1-688d-5de6bd7b58bc@intel.com>
In-Reply-To: <d828948f-2cd4-9bc1-688d-5de6bd7b58bc@intel.com>
From:   Victor Shih <victorshihgli@gmail.com>
Date:   Fri, 24 Feb 2023 18:22:40 +0800
Message-ID: <CAK00qKDyez21Cy=x=dp_yNPnconabPzJna6a+GmV_pHdsDEZOw@mail.gmail.com>
Subject: Re: [PATCH V6 11/24] mmc: sdhci-uhs2: add set_power() to support vdd2
To:     Adrian Hunter <adrian.hunter@intel.com>
Cc:     ulf.hansson@linaro.org, linux-mmc@vger.kernel.org,
        linux-kernel@vger.kernel.org, benchuanggli@gmail.com,
        HL.Liu@genesyslogic.com.tw, Greg.tu@genesyslogic.com.tw,
        takahiro.akashi@linaro.org, dlunev@chromium.org,
        Victor Shih <victor.shih@genesyslogic.com.tw>,
        Ben Chuang <ben.chuang@genesyslogic.com.tw>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

Hi, Adrian

On Fri, Jan 6, 2023 at 5:27 AM Adrian Hunter <adrian.hunter@intel.com> wrote:
>
> On 13/12/22 11:00, Victor Shih 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>
> > Signed-off-by: Victor Shih <victor.shih@genesyslogic.com.tw>
> > ---
> >  drivers/mmc/host/sdhci-uhs2.c | 46 +++++++++++++++++++++++++
> >  drivers/mmc/host/sdhci.c      | 63 +++++++++++++++++++----------------
> >  drivers/mmc/host/sdhci.h      |  1 +
> >  3 files changed, 82 insertions(+), 28 deletions(-)
> >
> > diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
> > index ae862e1eadab..780491781613 100644
> > --- a/drivers/mmc/host/sdhci-uhs2.c
> > +++ b/drivers/mmc/host/sdhci-uhs2.c
> > @@ -57,6 +57,13 @@ EXPORT_SYMBOL_GPL(sdhci_uhs2_dump_regs);
> >   *                                                                           *
> >  \*****************************************************************************/
> >
> > +static inline int mmc_opt_regulator_set_ocr(struct mmc_host *mmc,
> > +                                         struct regulator *supply,
> > +                                         unsigned short vdd_bit)
> > +{
> > +     return IS_ERR_OR_NULL(supply) ? 0 : mmc_regulator_set_ocr(mmc, supply, vdd_bit);
> > +}
> > +
> >  bool sdhci_uhs2_mode(struct sdhci_host *host)
> >  {
> >       return host->mmc->flags & MMC_UHS2_SUPPORT;
> > @@ -95,6 +102,45 @@ void sdhci_uhs2_reset(struct sdhci_host *host, u16 mask)
> >  }
> >  EXPORT_SYMBOL_GPL(sdhci_uhs2_reset);
> >
> > +static void sdhci_uhs2_set_power(struct sdhci_host *host, unsigned char mode,
> > +                       unsigned short vdd)
> > +{
> > +     struct mmc_host *mmc = host->mmc;
> > +     u8 pwr;
> > +
> > +     if (mode != MMC_POWER_OFF) {
> > +             pwr = sdhci_get_vdd_value(vdd);
> > +             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);
> > +
> > +             mmc_opt_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);
> > +             mmc_opt_regulator_set_ocr(mmc, mmc->supply.vmmc2, 0);
> > +     } else {
> > +             mmc_opt_regulator_set_ocr(mmc, mmc->supply.vmmc, vdd);
> > +             /* support 1.8v only for now */
> > +             mmc_opt_regulator_set_ocr(mmc, mmc->supply.vmmc2, fls(MMC_VDD2_165_195) - 1);
> > +
>                 /* Clear the power reg before setting a new value */
>                 sdhci_writeb(host, 0, SDHCI_POWER_CONTROL);
>

I will update it in V7 version.

> > +             /* 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);
> > +     }
> > +}
> > +
> >  /*****************************************************************************\
> >   *                                                                           *
> >   * Driver init/exit                                                          *
> > diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> > index 9b66b9a32c72..99633a3ef549 100644
> > --- a/drivers/mmc/host/sdhci.c
> > +++ b/drivers/mmc/host/sdhci.c
> > @@ -23,7 +23,7 @@
> >  #include <linux/regulator/consumer.h>
> >  #include <linux/pm_runtime.h>
> >  #include <linux/of.h>
> > -
> > +#include <linux/bug.h>
> >  #include <linux/leds.h>
> >
> >  #include <linux/mmc/mmc.h>
> > @@ -2061,41 +2061,48 @@ 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;
>
> It is simpler without pwr
>

I will update it in V7 version.

> > +
> > +     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;
>
>                 return SDHCI_POWER_180;
>

I will update it in V7 version.

> > +     case MMC_VDD_29_30:
> > +     case MMC_VDD_30_31:
> > +             pwr = SDHCI_POWER_300;
> > +             break;
>
>                 return SDHCI_POWER_300;
>

I will update it in V7 version.

> > +     case MMC_VDD_32_33:
> > +     case MMC_VDD_33_34:
>
> Missing:
>
>         /*
>          * 3.4 ~ 3.6V are valid only for those platforms where it's
>          * known that the voltage range is supported by hardware.
>          */
>         case MMC_VDD_34_35:
>         case MMC_VDD_35_36:
>
>

I will update it in V7 version.

> > +             pwr = SDHCI_POWER_330;
> > +             break;
>
>                 return SDHCI_POWER_330;
>

I will update it in V7 version.

> > +     default:
> > +             pwr = 0;
> > +             break;
>
>                 return 0;
>

I will update it in V7 version.

> > +     }
> > +
> > +     return pwr;
>
> Not needed. Control never reaches it anymore.
>

I will update it in V7 version.

> > +}
> > +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:
> > -             /*
> > -              * 3.4 ~ 3.6V are valid only for those platforms where it's
> > -              * known that the voltage range is supported by hardware.
> > -              */
> > -             case MMC_VDD_34_35:
> > -             case MMC_VDD_35_36:
> > -                     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;
> >               }
> >       }
> >
> > diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> > index f41c19c76994..df7fa0c0ebf8 100644
> > --- a/drivers/mmc/host/sdhci.h
> > +++ b/drivers/mmc/host/sdhci.h
> > @@ -840,6 +840,7 @@ 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);
> >  int sdhci_get_cd_nogpio(struct mmc_host *mmc);
>

Thanks, Victor Shih