Re: [PATCH V6 11/24] mmc: sdhci-uhs2: add set_power() to support vdd2

From: Adrian Hunter
Date: Thu Jan 05 2023 - 16:27:22 EST

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@xxxxxxxxxxxxxxxxxxx>
> Signed-off-by: AKASHI Takahiro <takahiro.akashi@xxxxxxxxxx>
> Signed-off-by: Victor Shih <victor.shih@xxxxxxxxxxxxxxxxxxx>
> ---
> 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);

> + /* 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

> +
> + 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;

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

return SDHCI_POWER_300;

> + 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:


> + pwr = SDHCI_POWER_330;
> + break;

return SDHCI_POWER_330;

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

return 0;

> + }
> +
> + return pwr;

Not needed. Control never reaches it anymore.

> +}
> +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);