Re: [RFC PATCH v3.1 16/27] mmc: sdhci-uhs2: add set_ios()

AKASHI Takahiro
2020-11-30T07:52:40Z

On Thu, Nov 26, 2020 at 10:17:11AM +0200, Adrian Hunter wrote:
> On 6/11/20 4:27 am, AKASHI Takahiro 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>
> > ---
> > drivers/mmc/host/sdhci-uhs2.c | 100 ++++++++++++++++++++++++++++++++++
> > drivers/mmc/host/sdhci-uhs2.h | 1 +
> > drivers/mmc/host/sdhci.c | 40 +++++++++-----
> > drivers/mmc/host/sdhci.h | 2 +
> > 4 files changed, 128 insertions(+), 15 deletions(-)
> >
> > diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
> > index d9e98c097bfe..637464748cc4 100644
> > --- a/drivers/mmc/host/sdhci-uhs2.c
> > +++ b/drivers/mmc/host/sdhci-uhs2.c
> > @@ -263,6 +263,74 @@ 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_ERR_INT_STATUS_EN);
> > + ier &= ~clear;
> > + ier |= set;
> > + sdhci_writel(host, ier, SDHCI_UHS2_ERR_INT_STATUS_EN);
> > + sdhci_writel(host, ier, SDHCI_UHS2_ERR_INT_SIG_EN);
> > +}
> > +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;
> > + unsigned long flags;
> > +
> > + /* FIXME: why lock? */
> > + spin_lock_irqsave(&host->lock, flags);
> > +
> > + /* UHS2 Timeout Control */
> > + sdhci_calc_timeout_uhs2(host, &cmd_res, &dead_lock);
> > +
> > + /* change to use calculate value */
> > + cmd_res |= dead_lock << SDHCI_UHS2_TIMER_CTRL_DEADLOCK_SHIFT;
> > +
> > + sdhci_uhs2_clear_set_irqs(host,
> > + SDHCI_UHS2_ERR_INT_STATUS_RES_TIMEOUT |
> > + SDHCI_UHS2_ERR_INT_STATUS_DEADLOCK_TIMEOUT,
> > + 0);
> > + sdhci_writeb(host, cmd_res, SDHCI_UHS2_TIMER_CTRL);
> > + sdhci_uhs2_clear_set_irqs(host, 0,
> > + SDHCI_UHS2_ERR_INT_STATUS_RES_TIMEOUT |
> > + SDHCI_UHS2_ERR_INT_STATUS_DEADLOCK_TIMEOUT);
> > +
> > + /* UHS2 timing */
> > + ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
> > + if (ios->timing == MMC_TIMING_UHS2)
> > + ctrl_2 |= SDHCI_CTRL_UHS_2 | SDHCI_CTRL_UHS2_INTERFACE_EN;
> > + else
> > + ctrl_2 &= ~(SDHCI_CTRL_UHS_2 | SDHCI_CTRL_UHS2_INTERFACE_EN);
> > + 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_set_power(host, ios->power_mode, ios->vdd);
> > + udelay(100);
> > +
> > + host->timing = ios->timing;
> > + sdhci_set_clock(host, host->clock);
>
> sdhci_set_ios_common() already called ->set_clock() and ->set_power(), so I
> am not really following what is going on here. Can you explain some more?

To be frank, I don't know. The logic in Intel's (and/or Ben's?)
original code does so.
What I changed is to remove the code of setting (ios->vdd and) ios->vdd2,
which is executed before calling set_power(), in __sdhci_uhs2_set_ios().

So yes, effectively it may be of no use to call set_power() here.

-Takahiro Akashi

> > +
> > + spin_unlock_irqrestore(&host->lock, flags);
> > +}
> > +
> > /*****************************************************************************\
> > * *
> > * MMC callbacks *
> > @@ -286,6 +354,37 @@ static int sdhci_uhs2_start_signal_voltage_switch(struct mmc_host *mmc,
> > return sdhci_start_signal_voltage_switch(mmc, ios);
> > }
> >
> > +void sdhci_uhs2_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
> > +{
> > + struct sdhci_host *host = mmc_priv(mmc);
> > +
> > + if (!(host->version >= SDHCI_SPEC_400) ||
> > + !(host->mmc->flags & MMC_UHS2_SUPPORT &&
> > + host->mmc->caps & MMC_CAP_UHS2)) {
> > + sdhci_set_ios(mmc, ios);
> > + return;
> > + }
> > +
> > + 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);
> > + if (!IS_ERR_OR_NULL(mmc->supply.vmmc2) &&
> > + ios->power_mode == MMC_POWER_OFF)
> > + mmc_regulator_set_ocr(mmc, mmc->supply.vmmc2, 0);
> > + return;
> > + }
> > +
> > + /* FIXME: host->timing = ios->timing */
> > +
> > + sdhci_set_ios_common(mmc, ios);
> > +
> > + __sdhci_uhs2_set_ios(mmc, ios);
> > +}
> > +
> > /*****************************************************************************\
> > * *
> > * Driver init/exit *
> > @@ -296,6 +395,7 @@ 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.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 efe70577bc74..c1ff4ac1ab7a 100644
> > --- a/drivers/mmc/host/sdhci-uhs2.h
> > +++ b/drivers/mmc/host/sdhci-uhs2.h
> > @@ -214,5 +214,6 @@ 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);
> > 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 0b741eb546cb..becb228330af 100644
> > --- a/drivers/mmc/host/sdhci.c
> > +++ b/drivers/mmc/host/sdhci.c
> > @@ -48,8 +48,6 @@
> > 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)
> > @@ -1836,6 +1834,9 @@ 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_UHS2:
> > + preset = sdhci_readw(host, SDHCI_PRESET_FOR_UHS2);
> > + break;
> > default:
> > pr_warn("%s: Invalid UHS-I mode selected\n",
> > mmc_hostname(host->mmc));
> > @@ -2249,20 +2250,9 @@ void sdhci_set_uhs_signaling(struct sdhci_host *host, unsigned timing)
> > }
> > EXPORT_SYMBOL_GPL(sdhci_set_uhs_signaling);
> >
> > -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);
> > - u8 ctrl;
> > -
> > - 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.
> > @@ -2299,6 +2289,25 @@ 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);
> > + u8 ctrl;
> > +
> > + 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 (host->ops->platform_send_init_74_clocks)
> > host->ops->platform_send_init_74_clocks(host, ios->power_mode);
> > @@ -2869,7 +2878,7 @@ 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)
> > @@ -2897,6 +2906,7 @@ 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 2b5b8295cf92..e84ebddb20d8 100644
> > --- a/drivers/mmc/host/sdhci.h
> > +++ b/drivers/mmc/host/sdhci.h
> > @@ -851,6 +851,8 @@ 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);
> >
>