diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c index fc65475a26ee..b461b290ce25 100644 --- a/drivers/mmc/core/sd.c +++ b/drivers/mmc/core/sd.c @@ -925,6 +925,13 @@ static int mmc_sd_init_card(struct mmc_host *host, u32 ocr, /* Card is an ultra-high-speed card */ mmc_sd_card_set_uhs(card); + + /* + * Since initialization is now complete, enable preset + * value registers for UHS-I cards. + */ + if (host->ops->enable_preset_value) + host->ops->enable_preset_value(host, true); } else { /* * Attempt to change to high-speed (if supported) @@ -1095,6 +1102,10 @@ int mmc_attach_sd(struct mmc_host *host) if (err) return err; + /* Disable preset value enable if already set since last time */ + if (host->ops->enable_preset_value) + host->ops->enable_preset_value(host, false); + err = mmc_send_app_op_cond(host, 0, &ocr); if (err) return err; diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index 8a56eacea34d..a1ab22415883 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -1649,6 +1649,37 @@ out: return err; } +static void sdhci_enable_preset_value(struct mmc_host *mmc, bool enable) +{ + struct sdhci_host *host; + u16 ctrl; + unsigned long flags; + + host = mmc_priv(mmc); + + /* Host Controller v3.00 defines preset value registers */ + if (host->version < SDHCI_SPEC_300) + return; + + spin_lock_irqsave(&host->lock, flags); + + ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2); + + /* + * We only enable or disable Preset Value if they are not already + * enabled or disabled respectively. Otherwise, we bail out. + */ + if (enable && !(ctrl & SDHCI_CTRL_PRESET_VAL_ENABLE)) { + ctrl |= SDHCI_CTRL_PRESET_VAL_ENABLE; + sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2); + } else if (!enable && (ctrl & SDHCI_CTRL_PRESET_VAL_ENABLE)) { + ctrl &= ~SDHCI_CTRL_PRESET_VAL_ENABLE; + sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2); + } + + spin_unlock_irqrestore(&host->lock, flags); +} + static const struct mmc_host_ops sdhci_ops = { .request = sdhci_request, .set_ios = sdhci_set_ios, @@ -1656,6 +1687,7 @@ static const struct mmc_host_ops sdhci_ops = { .enable_sdio_irq = sdhci_enable_sdio_irq, .start_signal_voltage_switch = sdhci_start_signal_voltage_switch, .execute_tuning = sdhci_execute_tuning, + .enable_preset_value = sdhci_enable_preset_value, }; /*****************************************************************************\ diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h index ca7007fdb399..6716bd12eccd 100644 --- a/include/linux/mmc/host.h +++ b/include/linux/mmc/host.h @@ -137,6 +137,7 @@ struct mmc_host_ops { int (*start_signal_voltage_switch)(struct mmc_host *host, struct mmc_ios *ios); int (*execute_tuning)(struct mmc_host *host); + void (*enable_preset_value)(struct mmc_host *host, bool enable); }; struct mmc_card;