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

AKASHI Takahiro
2020-11-30T07:16:38Z

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);
> >
>