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References: <20221213090047.3805-1-victor.shih@genesyslogic.com.tw>
 <20221213090047.3805-15-victor.shih@genesyslogic.com.tw> <fcd88dd6-4538-cb35-a4e8-750bef1a6c08@intel.com>
In-Reply-To: <fcd88dd6-4538-cb35-a4e8-750bef1a6c08@intel.com>
From:   Victor Shih <victorshihgli@gmail.com>
Date:   Thu, 26 Jan 2023 18:58:51 +0800
Message-ID: <CAK00qKB7byDgsRtRFVxFzDZAtrqTM7wny7q+zGqnY+M+sNAfUw@mail.gmail.com>
Subject: Re: [PATCH V6 14/24] mmc: sdhci-uhs2: add set_ios()
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 5:28 AM Adrian Hunter <adrian.hunter@intel.com> wrote:
>
> On 13/12/22 11:00, Victor Shih wrote:
> > This is a sdhci version of mmc's set_ios operation.
> > It covers both UHS-I and UHS-II.
> >
> > 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 | 96 +++++++++++++++++++++++++++++++++++
> >  drivers/mmc/host/sdhci-uhs2.h |  1 +
> >  drivers/mmc/host/sdhci.c      | 53 +++++++++++--------
> >  drivers/mmc/host/sdhci.h      |  2 +
> >  4 files changed, 131 insertions(+), 21 deletions(-)
> >
> > diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
> > index 00b1b69b49ea..3d52d35a91a5 100644
> > --- a/drivers/mmc/host/sdhci-uhs2.c
> > +++ b/drivers/mmc/host/sdhci-uhs2.c
> > @@ -213,6 +213,68 @@ void sdhci_uhs2_set_timeout(struct sdhci_host *host, struct mmc_command *cmd)
> >  }
> >  EXPORT_SYMBOL_GPL(sdhci_uhs2_set_timeout);
> >
> > +/**
> > + * sdhci_uhs2_clear_set_irqs - set Error Interrupt Status Enable register
> > + * @host:    SDHCI host
> > + * @clear:   bit-wise clear mask
> > + * @set:     bit-wise set mask
> > + *
> > + * Set/unset bits in UHS-II Error Interrupt Status Enable register
> > + */
> > +void sdhci_uhs2_clear_set_irqs(struct sdhci_host *host, u32 clear, u32 set)
> > +{
> > +     u32 ier;
> > +
> > +     ier = sdhci_readl(host, SDHCI_UHS2_INT_STATUS_ENABLE);
> > +     ier &= ~clear;
> > +     ier |= set;
> > +     sdhci_writel(host, ier, SDHCI_UHS2_INT_STATUS_ENABLE);
> > +     sdhci_writel(host, ier, SDHCI_UHS2_INT_SIGNAL_ENABLE);
> > +}
> > +EXPORT_SYMBOL_GPL(sdhci_uhs2_clear_set_irqs);
> > +
> > +static void __sdhci_uhs2_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
> > +{
> > +     struct sdhci_host *host = mmc_priv(mmc);
> > +     u8 cmd_res, dead_lock;
> > +     u16 ctrl_2;
> > +
> > +     /* UHS2 Timeout Control */
> > +     sdhci_calc_timeout_uhs2(host, &cmd_res, &dead_lock);
> > +
> > +     /* change to use calculate value */
> > +     cmd_res |= FIELD_PREP(SDHCI_UHS2_TIMER_CTRL_DEADLOCK_MASK, dead_lock);
> > +
> > +     sdhci_uhs2_clear_set_irqs(host,
> > +                               SDHCI_UHS2_INT_CMD_TIMEOUT |
> > +                               SDHCI_UHS2_INT_DEADLOCK_TIMEOUT,
> > +                               0);
> > +     sdhci_writeb(host, cmd_res, SDHCI_UHS2_TIMER_CTRL);
> > +     sdhci_uhs2_clear_set_irqs(host, 0,
> > +                               SDHCI_UHS2_INT_CMD_TIMEOUT |
> > +                               SDHCI_UHS2_INT_DEADLOCK_TIMEOUT);
> > +
> > +     /* UHS2 timing */
>
> Please extend comment to include:
>
>         Note, UHS2 timing is disabled when powering off
>
> > +     ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
> > +     if (ios->timing == MMC_TIMING_SD_UHS2)
> > +             ctrl_2 |= SDHCI_CTRL_UHS2 | SDHCI_CTRL_UHS2_ENABLE;
> > +     else
> > +             ctrl_2 &= ~(SDHCI_CTRL_UHS2 | SDHCI_CTRL_UHS2_ENABLE);
> > +     sdhci_writew(host, ctrl_2, SDHCI_HOST_CONTROL2);
> > +
> > +     if (!(host->quirks2 & SDHCI_QUIRK2_PRESET_VALUE_BROKEN))
> > +             sdhci_enable_preset_value(host, true);
> > +
> > +     if (host->ops->set_power)
> > +             host->ops->set_power(host, ios->power_mode, ios->vdd);
> > +     else
> > +             sdhci_uhs2_set_power(host, ios->power_mode, ios->vdd);
>
> sdhci_set_ios_common() already set the power.  Are both needed?
>
> > +     udelay(100);
>
> Please add a comment for why this delay is here.
>
> > +
> > +     host->timing = ios->timing;
>
> Please move this up to where the timing change is.
>

The ios->timing was changed in sd_uhs2_power_up function and not
modified in this function(__sdhci_uhs2_set_ios), therefore would you
want me to move this to the sd_uhs2_power_up function?

As I know the ios->timing is used in sdhci_set_clock function, setting
the host->timing before call the sdhci_set_clock function ensures that
the host->timing used in sdhci_set_clock function is the most recent
value. What do you think about this?

> > +     sdhci_set_clock(host, host->clock);
> > +}
> > +
> >  /*****************************************************************************\
> >   *                                                                           *
> >   * MMC callbacks                                                             *
> > @@ -234,6 +296,39 @@ static int sdhci_uhs2_start_signal_voltage_switch(struct mmc_host *mmc,
> >       return sdhci_start_signal_voltage_switch(mmc, ios);
> >  }
> >
> > +int sdhci_uhs2_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
>
> Should be static
>
> > +{
> > +     struct sdhci_host *host = mmc_priv(mmc);
> > +
> > +     if (!(host->version >= SDHCI_SPEC_400) ||
> > +         !(host->mmc->flags & MMC_UHS2_SUPPORT &&
> > +           host->mmc->caps2 & MMC_CAP2_SD_UHS2)) {
>
> This can be just:
>
>         if (!sdhci_uhs2_mode(host)) {
>
> Not sure if this is actually possible?
>
> > +             sdhci_set_ios(mmc, ios);
> > +             return 0;
> > +     }
> > +
> > +     if (ios->power_mode == MMC_POWER_UNDEFINED)
> > +             return 0;
> > +
> > +     if (host->flags & SDHCI_DEVICE_DEAD) {
> > +             if (!IS_ERR(mmc->supply.vmmc) &&
> > +                 ios->power_mode == MMC_POWER_OFF)
> > +                     mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);
> > +             if (!IS_ERR_OR_NULL(mmc->supply.vmmc2) &&
> > +                 ios->power_mode == MMC_POWER_OFF)
> > +                     mmc_regulator_set_ocr(mmc, mmc->supply.vmmc2, 0);
>
> This can be just:
>
>                 if (ios->power_mode == MMC_POWER_OFF) {
>                         mmc_opt_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);
>                         mmc_opt_regulator_set_ocr(mmc, mmc->supply.vmmc2, 0);
>                 }
>
> > +             return -1;
> > +     }
> > +
> > +     host->timing = ios->timing;
>
> __sdhci_uhs2_set_ios() does this so it is not needed here.
>
> > +
> > +     sdhci_set_ios_common(mmc, ios);
> > +
> > +     __sdhci_uhs2_set_ios(mmc, ios);
> > +
> > +     return 0;
> > +}
> > +
> >  /*****************************************************************************\
> >   *                                                                           *
> >   * Driver init/exit                                                          *
> > @@ -244,6 +339,7 @@ static int sdhci_uhs2_host_ops_init(struct sdhci_host *host)
> >  {
> >       host->mmc_host_ops.start_signal_voltage_switch =
> >               sdhci_uhs2_start_signal_voltage_switch;
> > +     host->mmc_host_ops.uhs2_set_ios = sdhci_uhs2_set_ios;
> >
> >       return 0;
> >  }
> > diff --git a/drivers/mmc/host/sdhci-uhs2.h b/drivers/mmc/host/sdhci-uhs2.h
> > index a58ef19c08aa..184fee80253c 100644
> > --- a/drivers/mmc/host/sdhci-uhs2.h
> > +++ b/drivers/mmc/host/sdhci-uhs2.h
> > @@ -178,5 +178,6 @@ void sdhci_uhs2_dump_regs(struct sdhci_host *host);
> >  bool sdhci_uhs2_mode(struct sdhci_host *host);
> >  void sdhci_uhs2_reset(struct sdhci_host *host, u16 mask);
> >  void sdhci_uhs2_set_timeout(struct sdhci_host *host, struct mmc_command *cmd);
> > +void sdhci_uhs2_clear_set_irqs(struct sdhci_host *host, u32 clear, u32 set);
> >
> >  #endif /* __SDHCI_UHS2_H */
> > diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> > index 99633a3ef549..49bbdc155b2b 100644
> > --- a/drivers/mmc/host/sdhci.c
> > +++ b/drivers/mmc/host/sdhci.c
> > @@ -47,8 +47,6 @@
> >  static unsigned int debug_quirks = 0;
> >  static unsigned int debug_quirks2;
> >
> > -static void sdhci_enable_preset_value(struct sdhci_host *host, bool enable);
> > -
> >  static bool sdhci_send_command(struct sdhci_host *host, struct mmc_command *cmd);
> >
> >  void sdhci_dumpregs(struct sdhci_host *host)
> > @@ -1877,6 +1875,9 @@ static u16 sdhci_get_preset_value(struct sdhci_host *host)
> >       case MMC_TIMING_MMC_HS400:
> >               preset = sdhci_readw(host, SDHCI_PRESET_FOR_HS400);
> >               break;
> > +     case MMC_TIMING_SD_UHS2:
> > +             preset = sdhci_readw(host, SDHCI_PRESET_FOR_UHS2);
> > +             break;
> >       default:
> >               pr_warn("%s: Invalid UHS-I mode selected\n",
> >                       mmc_hostname(host->mmc));
> > @@ -2325,24 +2326,9 @@ static bool sdhci_presetable_values_change(struct sdhci_host *host, struct mmc_i
> >              (sdhci_preset_needed(host, ios->timing) || host->drv_type != ios->drv_type);
> >  }
> >
> > -void sdhci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
> > +void sdhci_set_ios_common(struct mmc_host *mmc, struct mmc_ios *ios)
> >  {
> >       struct sdhci_host *host = mmc_priv(mmc);
> > -     bool reinit_uhs = host->reinit_uhs;
> > -     bool turning_on_clk = false;
> > -     u8 ctrl;
> > -
> > -     host->reinit_uhs = false;
> > -
> > -     if (ios->power_mode == MMC_POWER_UNDEFINED)
> > -             return;
> > -
> > -     if (host->flags & SDHCI_DEVICE_DEAD) {
> > -             if (!IS_ERR(mmc->supply.vmmc) &&
> > -                 ios->power_mode == MMC_POWER_OFF)
> > -                     mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);
> > -             return;
> > -     }
> >
> >       /*
> >        * Reset the chip on each power off.
> > @@ -2359,8 +2345,6 @@ void sdhci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
> >               sdhci_enable_preset_value(host, false);
> >
> >       if (!ios->clock || ios->clock != host->clock) {
> > -             turning_on_clk = ios->clock && !host->clock;
> > -
> >               host->ops->set_clock(host, ios->clock);
> >               host->clock = ios->clock;
> >
> > @@ -2381,6 +2365,32 @@ void sdhci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
> >               host->ops->set_power(host, ios->power_mode, ios->vdd);
> >       else
> >               sdhci_set_power(host, ios->power_mode, ios->vdd);
> > +}
> > +EXPORT_SYMBOL_GPL(sdhci_set_ios_common);
> > +
> > +void sdhci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
> > +{
> > +     struct sdhci_host *host = mmc_priv(mmc);
> > +     bool reinit_uhs = host->reinit_uhs;
> > +     bool turning_on_clk = false;
> > +     u8 ctrl;
> > +
> > +     host->reinit_uhs = false;
> > +
> > +     if (ios->power_mode == MMC_POWER_UNDEFINED)
> > +             return;
> > +
> > +     if (host->flags & SDHCI_DEVICE_DEAD) {
> > +             if (!IS_ERR(mmc->supply.vmmc) &&
> > +                 ios->power_mode == MMC_POWER_OFF)
> > +                     mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);
> > +             return;
> > +     }
> > +
> > +     sdhci_set_ios_common(mmc, ios);
> > +
> > +     if (!ios->clock || ios->clock != host->clock)
> > +             turning_on_clk = ios->clock && !host->clock;
> >
> >       if (host->ops->platform_send_init_74_clocks)
> >               host->ops->platform_send_init_74_clocks(host, ios->power_mode);
> > @@ -2959,7 +2969,7 @@ int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
> >  }
> >  EXPORT_SYMBOL_GPL(sdhci_execute_tuning);
> >
> > -static void sdhci_enable_preset_value(struct sdhci_host *host, bool enable)
> > +void sdhci_enable_preset_value(struct sdhci_host *host, bool enable)
> >  {
> >       /* Host Controller v3.00 defines preset value registers */
> >       if (host->version < SDHCI_SPEC_300)
> > @@ -2987,6 +2997,7 @@ static void sdhci_enable_preset_value(struct sdhci_host *host, bool enable)
> >               host->preset_enabled = enable;
> >       }
> >  }
> > +EXPORT_SYMBOL_GPL(sdhci_enable_preset_value);
> >
> >  static void sdhci_post_req(struct mmc_host *mmc, struct mmc_request *mrq,
> >                               int err)
> > diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> > index df7fa0c0ebf8..c2f989dc2361 100644
> > --- a/drivers/mmc/host/sdhci.h
> > +++ b/drivers/mmc/host/sdhci.h
> > @@ -850,6 +850,8 @@ void sdhci_set_bus_width(struct sdhci_host *host, int width);
> >  void sdhci_reset(struct sdhci_host *host, u8 mask);
> >  void sdhci_set_uhs_signaling(struct sdhci_host *host, unsigned timing);
> >  int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode);
> > +void sdhci_enable_preset_value(struct sdhci_host *host, bool enable);
> > +void sdhci_set_ios_common(struct mmc_host *mmc, struct mmc_ios *ios);
> >  void sdhci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios);
> >  int sdhci_start_signal_voltage_switch(struct mmc_host *mmc,
> >                                     struct mmc_ios *ios);
>

Thanks, Victor Shih