diff options
Diffstat (limited to 'drivers/mmc')
| -rw-r--r-- | drivers/mmc/host/sdhci-msm.c | 48 |
1 files changed, 47 insertions, 1 deletions
diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c index cc4274a023fd3..1f59f00089302 100644 --- a/drivers/mmc/host/sdhci-msm.c +++ b/drivers/mmc/host/sdhci-msm.c @@ -410,6 +410,52 @@ retry: return rc; } +static void sdhci_msm_set_uhs_signaling(struct sdhci_host *host, + unsigned int uhs) +{ + struct mmc_host *mmc = host->mmc; + u16 ctrl_2; + + ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2); + /* Select Bus Speed Mode for host */ + ctrl_2 &= ~SDHCI_CTRL_UHS_MASK; + switch (uhs) { + case MMC_TIMING_UHS_SDR12: + ctrl_2 |= SDHCI_CTRL_UHS_SDR12; + break; + case MMC_TIMING_UHS_SDR25: + ctrl_2 |= SDHCI_CTRL_UHS_SDR25; + break; + case MMC_TIMING_UHS_SDR50: + ctrl_2 |= SDHCI_CTRL_UHS_SDR50; + break; + case MMC_TIMING_MMC_HS200: + case MMC_TIMING_UHS_SDR104: + ctrl_2 |= SDHCI_CTRL_UHS_SDR104; + break; + case MMC_TIMING_UHS_DDR50: + case MMC_TIMING_MMC_DDR52: + ctrl_2 |= SDHCI_CTRL_UHS_DDR50; + break; + } + + /* + * When clock frequency is less than 100MHz, the feedback clock must be + * provided and DLL must not be used so that tuning can be skipped. To + * provide feedback clock, the mode selection can be any value less + * than 3'b011 in bits [2:0] of HOST CONTROL2 register. + */ + if (host->clock <= 100000000 && + (uhs == MMC_TIMING_MMC_HS400 || + uhs == MMC_TIMING_MMC_HS200 || + uhs == MMC_TIMING_UHS_SDR104)) + ctrl_2 &= ~SDHCI_CTRL_UHS_MASK; + + dev_dbg(mmc_dev(mmc), "%s: clock=%u uhs=%u ctrl_2=0x%x\n", + mmc_hostname(host->mmc), host->clock, uhs, ctrl_2); + sdhci_writew(host, ctrl_2, SDHCI_HOST_CONTROL2); +} + static const struct of_device_id sdhci_msm_dt_match[] = { { .compatible = "qcom,sdhci-msm-v4" }, {}, @@ -422,7 +468,7 @@ static const struct sdhci_ops sdhci_msm_ops = { .reset = sdhci_reset, .set_clock = sdhci_set_clock, .set_bus_width = sdhci_set_bus_width, - .set_uhs_signaling = sdhci_set_uhs_signaling, + .set_uhs_signaling = sdhci_msm_set_uhs_signaling, }; static const struct sdhci_pltfm_data sdhci_msm_pdata = { |