diff options
Diffstat (limited to 'drivers/mmc/host')
| -rw-r--r-- | drivers/mmc/host/sdhci.c | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index 8a56eacea34..a1ab2241588 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, }; /*****************************************************************************\ |