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| author | Prathamesh Shete <pshete@nvidia.com> | 2021-12-14 14:36:53 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-12-29 14:28:56 +0300 |
| commit | 46e2fc260543bba2ec2ce3f72db2f62174329d20 (patch) | |
| tree | 61f0003cbd892ad7cf710b8b8aa68fe386141875 /drivers/mmc/host | |
| parent | e5dd3e61baed74d0abfc63d05d69dbff9e48d1bd (diff) | |
| download | linux-46e2fc260543bba2ec2ce3f72db2f62174329d20.tar.xz | |
mmc: sdhci-tegra: Fix switch to HS400ES mode
commit 4fc7261dbab139d3c64c3b618262504e16cfe7ee upstream.
When CMD13 is sent after switching to HS400ES mode, the bus
is operating at either MMC_HIGH_26_MAX_DTR or MMC_HIGH_52_MAX_DTR.
To meet Tegra SDHCI requirement at HS400ES mode, force SDHCI
interface clock to MMC_HS200_MAX_DTR (200 MHz) so that host
controller CAR clock and the interface clock are rate matched.
Signed-off-by: Prathamesh Shete <pshete@nvidia.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Fixes: dfc9700cef77 ("mmc: tegra: Implement HS400 enhanced strobe")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20211214113653.4631-1-pshete@nvidia.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/mmc/host')
| -rw-r--r-- | drivers/mmc/host/sdhci-tegra.c | 43 |
1 files changed, 26 insertions, 17 deletions
diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c index a5001875876b..9762ffab2e23 100644 --- a/drivers/mmc/host/sdhci-tegra.c +++ b/drivers/mmc/host/sdhci-tegra.c @@ -356,23 +356,6 @@ static void tegra_sdhci_set_tap(struct sdhci_host *host, unsigned int tap) } } -static void tegra_sdhci_hs400_enhanced_strobe(struct mmc_host *mmc, - struct mmc_ios *ios) -{ - struct sdhci_host *host = mmc_priv(mmc); - u32 val; - - val = sdhci_readl(host, SDHCI_TEGRA_VENDOR_SYS_SW_CTRL); - - if (ios->enhanced_strobe) - val |= SDHCI_TEGRA_SYS_SW_CTRL_ENHANCED_STROBE; - else - val &= ~SDHCI_TEGRA_SYS_SW_CTRL_ENHANCED_STROBE; - - sdhci_writel(host, val, SDHCI_TEGRA_VENDOR_SYS_SW_CTRL); - -} - static void tegra_sdhci_reset(struct sdhci_host *host, u8 mask) { struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); @@ -793,6 +776,32 @@ static void tegra_sdhci_set_clock(struct sdhci_host *host, unsigned int clock) } } +static void tegra_sdhci_hs400_enhanced_strobe(struct mmc_host *mmc, + struct mmc_ios *ios) +{ + struct sdhci_host *host = mmc_priv(mmc); + u32 val; + + val = sdhci_readl(host, SDHCI_TEGRA_VENDOR_SYS_SW_CTRL); + + if (ios->enhanced_strobe) { + val |= SDHCI_TEGRA_SYS_SW_CTRL_ENHANCED_STROBE; + /* + * When CMD13 is sent from mmc_select_hs400es() after + * switching to HS400ES mode, the bus is operating at + * either MMC_HIGH_26_MAX_DTR or MMC_HIGH_52_MAX_DTR. + * To meet Tegra SDHCI requirement at HS400ES mode, force SDHCI + * interface clock to MMC_HS200_MAX_DTR (200 MHz) so that host + * controller CAR clock and the interface clock are rate matched. + */ + tegra_sdhci_set_clock(host, MMC_HS200_MAX_DTR); + } else { + val &= ~SDHCI_TEGRA_SYS_SW_CTRL_ENHANCED_STROBE; + } + + sdhci_writel(host, val, SDHCI_TEGRA_VENDOR_SYS_SW_CTRL); +} + static unsigned int tegra_sdhci_get_max_clock(struct sdhci_host *host) { struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); |