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

From: Adrian Hunter
Date: Thu Nov 26 2020 - 03:16:53 EST

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@xxxxxxxxxxxxxxxxxxx>
> Signed-off-by: AKASHI Takahiro <takahiro.akashi@xxxxxxxxxx>
> ---
> 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.

> +{
> + 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

> + 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) {
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

> + 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.

> + 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);
>